Optimised liquid-phase oxidation

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and a reactor-type bubble column. A stream of oxidising agent which contains molecular oxygen and a stream of starting material containing the oxidised compound are fed into the reaction zone of the bubble column reactor. As a result of oxidation, a solid-phase product from at least approximately 10 wt % of the oxidised compound is obtained. At least a portion of the reaction medium containing the solid-phase product is taken from the reaction zone through one or more openings lying at a higher level than the inlet zone of at least a portion of the molecular oxygen into the reaction zone. Average gas flow rate per unit cross section of the stream at half the height of the said reaction medium is kept equal to at least approximately 0.3 m/s. The proposed installation has a bubble column reactor with a perforated shell, a reaction medium container and a channel designed for carrying spent reaction medium into the container.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

32 cl, 35 dwg, 7 tbl, 13 ex

 

The technical FIELD

This invention in General relates to a method of liquid-phase catalytic oxidation of aromatic compounds. One aspect of the invention relates to the partial oxidation dialkylamino connection (for example, para-xylene) with raw crude aromatic dicarboxylic acid (e.g., raw crude terephthalic acid), which can then be subjected to purification and separation. Another aspect of the invention relates to an improved bubbler reactor column, which allows for more efficient and economical way of liquid-phase oxidation.

The LEVEL of TECHNOLOGY

The reaction liquid-phase oxidation is used in a wide range of existing commercial methods. For example, liquid-phase oxidation of currently used for the oxidation of aldehydes to obtain acids (e.g. propionic aldehyde to obtain propionic acid), oxidation of cyclohexane to obtain adipic acid and oxidation of alkylaromatic to obtain alcohols, acids or decislon. By way of commercial oxidation, with particularly important and relevant to the last category (oxidation alkylaromatic)is the liquid-phase catalytic partial oxidation of para-xylene to obtain terephthalic acid. Reptilia acid is an important compound, characterized by a wide range of applications. The main use case of terephthalic acid is used as a source of raw materials for the production of polyethylene terephthalate (PET). PET is a well-known plastic used in large quantities around the world to obtain products such as bottles, fibers and packaging.

In a typical method of liquid-phase oxidation, including partial oxidation of para-xylene to obtain terephthalic acid, the flow of liquid source material supplied and the flow of gaseous oxidant is injected into the reactor and in the reactor, they form a multiphase reaction medium. Introduced into the reactor the flow of liquid source feed material contains at least one oxidizable organic compound (for example, para-xylene), while the flow of gas-phase oxidant contains molecular oxygen. At least part of the molecular oxygen introduced into the reactor as a gas dissolved in a liquid phase reaction medium that ensures the availability of oxygen for liquid-phase reactions. If the liquid phase of the multiphase reaction medium will contain insufficient concentration of molecular oxygen (i.e., if certain parts of the reaction medium will be "oxygen-depleted"), then there is lateline adverse reactions can lead to the formation of impurities, and/or the target reaction can slow down the speed. If the liquid phase reaction medium will contain excessively little oxidizable compounds, then the reaction rate may be undesirable low. In addition, if the liquid phase reaction medium will contain excess concentration of oxidizable compounds, then additional undesirable side reactions may lead to the formation of impurities.

Commonly used reactors liquid-phase oxidation is equipped with means for stirring, intended for mixing multi-phase reaction medium contained in them. Stirring of the reaction medium is carried out in order to promote the dissolution of molecular oxygen in the liquid phase reaction medium, keeping relatively homogeneous concentrations of dissolved oxygen in the liquid phase reaction medium and incubation in the liquid phase reaction medium relatively homogeneous concentrations of oxidizable organic compounds.

Stirring of the reaction medium subjected to liquid-phase oxidation, often carried out using a mechanical means of mixing in containers, such as, for example, capacitive reactors with continuous mixing (CSTR). Despite the fact that the CSTR reactors can provide thorough mixing reactionnaire, reactors CSTR has several disadvantages. For example, the CSTR reactors are characterized by relatively high capital costs due to having the need for expensive motors, bearings, water seal and drive shafts and/or complex mixing mechanisms. In addition, rotating and/or oscillating mechanical components commonly used reactors CSTR require regular technology services. Work and stop time associated with conducting such maintenance, increase operating costs for reactors CSTR. However, even with regular maintenance mechanical mixing system used in the CSTR reactors, prone to failure of mechanical parts and may require replacement after relatively short periods of time.

Bubble column reactor represent an attractive alternative for CSTR reactors and other reactors oxidation with mechanical stirring. Bubble column reactor provide mixing of the reaction medium without any need for expensive and unreliable mechanical equipment. Bubble column reactor typically includes an elongated upright the reaction zone within which is contained Acciona environment. Stirring of the reaction medium in the reaction zone is mainly due to the natural buoyancy of gas bubbles rising through the liquid phase reaction medium. This is due to the natural emergence of mixing achieved in the bubble reactor columns, leads to the reduction of capital costs and maintenance costs in comparison with a reactor with mechanical stirring. Furthermore, essentially no moving mechanical parts associated with bubbling reactor columns, provides the system of oxidation, which is less prone to failure of the mechanical part in relation to the reactor with mechanical agitation.

If the liquid-phase partial oxidation of para-xylene will conduct commonly used in the oxidation reactor (CSTR or bubble column), then the product is taken from the reactor will usually be a suspension containing crude crude terephthalic acid (CTA) and the mother liquor. One HUNDRED is characterized by relatively high levels of impurities (for example, 4-carboxybenzene, para-Truelove acid, fluorenone and other colored substances), which makes it unsuitable for use as a source of raw materials for the production of PET. Thus, one HUNDRED received about is a rule used in the oxidation reactors, usually subjected to a process of purification, which turns a HUNDRED in purified terephthalic acid (MOUTH), suitable for use in obtaining PET.

One typical method of cleaning during the transformation of a HUNDRED in the MOUTH includes the following stages: (1) the replacement of the mother liquor in suspension, containing a HUNDRED, on the water, (2) heating the suspension HUNDRED/water for dissolving a HUNDRED in water, (3) catalytic hydrogenation of a solution of a HUNDRED/water for the conversion of the impurities in the more desirable and/or easier detachable connection, (4) deposition resulting from the MOUTH of subjected to hydrogenation solution when using multiple stages of crystallization and (5) separating the crystallized MOUTH from the remaining liquids. Despite its effectiveness, this type of commonly used cleaning method can be very expensive. Individual factors contributing to the high cost of commonly used cleaning methods one HUNDRED, include, for example, thermal energy required to stimulate the dissolution of a HUNDRED in the water, catalyst, necessary for carrying out the hydrogenation, the flow of hydrogen required for hydrogenation, the loss of output caused by the hydrogenation of some parts of terephthalic acid, and the presence of several capacities needed to conduct multi-crystal is Itachi. Thus, it would be desirable product offering of a HUNDRED, which can be cleaned without any needs stimulated with heat-dissolved in water, hydrogenation and/or multi-stage crystallization.

The PURPOSE of the INVENTION

Therefore, the aim of the present invention is to offer a more efficient and economical reactor and method of liquid-phase oxidation.

Another objective of the invention is to offer a more efficient and economical reactor and method for liquid-phase catalytic partial oxidation of para-xylene to obtain terephthalic acid.

Another objective of the invention is to offer a bubble column reactor, which facilitates improved reactions liquid-phase oxidation at low efficiency of formation of impurities.

Another object of the invention is to offer a more efficient and cost-effective system designed for obtaining pure terephthalic acid (MOUTH) in the liquid-phase oxidation of para-xylene with raw crude terephthalic acid (CTA), and after that cleaning one HUNDRED to obtain the MOUTH.

An additional objective of the invention is to offer a bubble column reactor, intended for oxidation of para-xylene and obtain product is one HUNDRED, able to receive treatment without any needs stimulated by heating the dissolution of a HUNDRED in the water, hydrogenation of dissolved HUNDRED and/or multi-stage crystallization gidrirovannoe MOUTH.

It should be noted that the scope of the present invention defined in the attached claims is not limited to methods or devices, which are able to ensure the implementation of all the objectives listed above. Instead, the scope of the claimed invention may include a wide range of systems that do not allow you to achieve all or any of the above purposes. Additional objectives and advantages of the present invention will become obvious to a person skilled in the relevant field of technology after reading the following detailed description and accompanying drawings.

SUMMARY of INVENTION

One embodiment of the present invention relates to a method comprising the following stages: (a) introducing a flow of oxidant containing molecular oxygen in the reaction zone bubble column reactor; (b) oxidation of the oxidizable compound in a liquid phase, multi-phase reaction medium contained in the reaction zone where the oxidation results in the reaction medium, of at least about 10 mass numbers of the oxidizable compound solid-phase product, where sredneuralskoj flow rate per cross sectional area of flow at half the height of the reaction medium is at least approximately 0.3 meters per second; and (C) selecting at least part of the solid product from the reaction zone through one or more holes elevated location, where at least part of the molecular oxygen fed into the reaction zone below the holes elevated location.

Another embodiment of the present invention relates to a method comprising the following stages: (a) introducing a flow of oxidant containing molecular oxygen in the reaction zone bubble column reactor; (b) oxidation of the oxidizable compound in a liquid phase, multi-phase reaction medium contained in the reaction zone; and (C) selecting at least part of the reaction medium from the reaction zone through one or more holes elevated location, where at least part of the molecular oxygen fed into the reaction zone below the holes elevated location where the temperature of the reaction medium in the holes elevated location, at least about 1°C higher than the temperature of the reaction medium at the lowest point in the reaction zone.

Another embodiment of the present invention relates to a method obtained the I terephthalic acid, includes the following stages: (a) introducing a stream predominantly liquid source feed material containing para-xylene in the reaction zone bubble column reactor; (b) introducing into the reaction zone of the flow is predominantly gaseous oxidant containing molecular oxygen; (C) oxidizing para-xylene in a liquid phase reaction medium contained in the reaction zone, to obtain, thus, raw crude terephthalic acid; (d) selecting at least part of the raw crude terephthalic acid from the reaction zone through one or more holes elevated location, where at least part of para-xylene and at least part of the molecular oxygen enter into the reaction zone below the holes elevated location; and (e) oxidizing at least part of the raw crude terephthalic acid in a secondary oxidation reactor to obtain, thus, purer terephthalic acid.

As another embodiment of the present invention relates to a bubbling reactor column intended for the reaction between the predominately liquid-phase stream and a predominately gas-phase stream to obtain, thus, the solid-phase product. Bubble column reactor includes a shell capacity, one is whether a few holes for gas, one or more openings for fluid and one or more holes elevated location for the product. The shell of the vessel defines an extended reaction zone. The reaction zone includes the normally lower edge and a normally upper edge, spaced from each other in axial length (L). The reaction zone is characterized by a maximum diameter (D) and the ratio L:D, equal to at least about 6:1. One or more holes for gas provide to the introduction of gas-phase stream into the reaction zone. At least one of the holes for the gas is separated from the normally lower edge of the reaction zone at an axial distance less than approximately 0,25D. One or more openings to provide fluid introduction liquid-phase stream into the reaction zone. At least about 50 percent of the total surface area of the living section, certain all the holes for the fluid are less than about 2,5D from the hole for the gas closest to the normally lower edge. One or more holes elevated location to provide product selection solid-phase product from the reaction zone. In comparison, at least one of the holes for the gas and at least one of the holes for the fluid hole for a product in the axial direction have the further from normal bottom edge.

BRIEF DESCRIPTION of DRAWINGS

Preferred implementations of the invention are described in detail hereinafter with reference to the accompanying drawings where:

Figure 1 is a side view of the oxidation reactor, constructed in accordance with one implementation of the present invention, particularly illustrating the introduction of streams of initial feed material, oxidizer and medium irrigation in the reactor, the presence in the reactor of the multi-phase reaction medium and extraction of gas and slurry from the top and bottom of the reactor, respectively;

Figure 2 is an enlarged side view in cross section of the bottom of the bubble column reactor by line 2-2 on figure 3, particularly illustrating the location and configuration of the bubbler oxidant used for introduction into the reactor oxidant stream;

Figure 3 is a top view for the bubbler oxidant figure 2, particularly illustrating the holes for the oxidant in the area of the top of the bubbler oxidant;

Figure 4 is a bottom view for the bubbler oxidant figure 2, particularly illustrating the holes for the oxidant in the area of the bottom of the bubbler oxidant;

Figure 5 is a side view in cross section of the bubbler oxidant, along the line 5-5 on figure 3, particularly illustrating the orientation of the holes oxide is of Italia in the areas of the top and bottom of the bubbler oxidant;

Figure 6 is an enlarged side view of the lower part of the bubble column reactor, in particular, illustrating a system designed for introduction into the reactor flow of the source material supplied in several spaced vertical positions;

Figure 7 is a top view in section, along the line 7-7 in figure 6, particularly illustrating how the system of the introduction of the original feed material, shown in figure 6, controls the flow of the original feed material in the preferred radial feed source feed material (FZ) and more than one azimuthal quadrant (Q1, Q2, Q3, Q4);

Figure 8 is a top view in section, similar to figure 7 but illustrating an alternative means issue flow source feed material into the reactor using a bayonet tubes, each of which has many small holes for the source of the feed material;

Figure 9 is an isometric drawings for the alternative system intended for the introduction of a flow of the source material supplied to the reaction zone in several spaced vertical positions without any need for multiple entry points into the container, in particular, illustrating that the system of distribution of the original feed material may at least partly be based on the bubbler oxidant;

Figure 10 is a side view of a distribution system source feed material with a single point of entry capacity and bubbler oxidant, is illustrated in figure 9;

Figure 11 is a top view in section, along the line 11-11 in figure 10, and additionally illustrating a distribution system source feed material with a single point of entry into the vessel based on the bubbler oxidant;

Figure 12 is an isometric drawings for alternative bubbler oxidant, all holes oxidant which are located in the area of lower annular element;

Figure 13 is a top view of the alternate bubbler oxidant figure 12;

Figure 14 is a bottom view of the alternative bubbler oxidant figures 12, particularly illustrating the location of the lower holes for introducing the oxidant stream into the reaction zone;

Figure 15 is a side view in cross section of the bubbler oxidant, along the line 15-15 in figure 13, particularly illustrating the orientation of the bottom hole oxidant;

Figure 16 is a side view of a bubble column reactor equipped with internal deaeration capacity, location is close to the bottom outlet of the reactor;

Figure 17 is an enlarged side view in cross section of the lower part of the bubble column reactor of figure 16, along the line 17-17 in figure 18, in particular, illustrating the configuration of the inner deaerating tank, located at the bottom outlet bubble column reactor;

Figure 18 is a top view in section, along the line 18-18 in figure 16, in particular, illustrating a flow conditioner located in the deaeration capacity;

Figure 19 is a side view of a bubble column reactor equipped with external deaeration capacity, illustrating the method by which part of the deaerated suspension, leaving the bottom of the deaerating tank, can be used for washing lines reduce the fill factor, which is connected with the bottom of the reactor;

Figure 20 is a side view of a bubble column reactor, equipped with a hybrid internal/external deaeration capacity, intended for separating the gas phase reaction medium selected from a side position elevated location in the reactor;

Figure 21 is a side view of a bubble column reactor equipped with alternative hybrid deaeration capacity in the vicinity of the bottom of the reactor;

Figure 22 presents yet an enlarged side view in cross section of the lower part of the bubble column reactor of figure 21, in particular, illustrating the use of alternative bubbler oxidant, using the channels of the inlet holes that accept the flow of oxidant through the bottom plate of the reactor;

Figure 23 is an enlarged side view in section, similar to figure 22, in particular, illustrating an alternative means of introducing the oxidant stream into the reactor through the many holes in the bottom plate of the reactor and optionally with the use of rumble strips for a more uniform distribution of the flow of oxidant in the reactor;

Figure 24 is a side view of a bubble column reactor using an internal channel for the flow in order to enhance the dispersion of oxidizable compounds in the recirculation of the reaction medium with its transition from the upper part of the reactor in the lower part of the reactor;

Figure 25 is a side view of a bubble column reactor using an external channel for the flow in order to enhance the dispersion of oxidizable compounds in the recirculation of the reaction medium with its transition from the upper part of the reactor in the lower part of the reactor;

Figure 26 is a side view in cross section of a horizontal eductor that can be used to improve the dispersion of oxidizable compounds in R is the actor oxidation, in particular, illustrating eductor, which uses the incoming liquid source supplied material to tighten the reaction medium in eductor and produces a mixture of the original feed material and reaction medium in the reaction zone at high speed;

Figure 27 is a side view in cross section of vertical eductor that can be used to improve the dispersion of oxidizable compounds in the oxidation reactor, in particular, illustrating eductor, which combines liquid source supplied material and gas from the inlet holes and uses the combined two-phase fluid environment for tightening the reaction medium in eductor, and produces a mixture of liquid source feed gas inlet and a reaction medium in the reaction zone at high speed;

Figure 28 is a side view of a bubble column reactor containing a multiphase reaction medium, in particular, illustrating the reaction medium is theoretically divided into 30 horizontal lobes with equal volume in order to quantitatively establish certain gradients in the reaction environment;

Figure 29 is a side view of a bubble column reactor containing a multiphase reaction medium, in particular, illustrating the first and second discrete the 20-percent continuous volume of the reaction medium, which are characterized by substantially different oxygen concentrations and/or rates of consumption of oxygen;

Figure 30 is a side view of two spaced one above the other reaction vessels, with or without the use of an optional mechanical mixing, containing multiphase reaction medium, in particular, illustrating the fact that capacity can accommodate discrete 20-percent continuous volume of the reaction medium, characterized by significantly different oxygen concentrations and/or rates of consumption of oxygen;

Figure 31 is a side view of three adjacent each other reaction vessels, with or without the use of an optional mechanical mixing, containing multiphase reaction medium, in particular, illustrating the fact that capacity can accommodate discrete 20-percent continuous volume of the reaction medium, characterized by significantly different oxygen concentrations and/or rates of consumption of oxygen;

Figures 32A and 32V represent the enlarged image for particles of raw crude terephthalic acid (CTA), obtained in accordance with one implementation of the present invention, particularly illustrating that each particle is a HUNDRED is asticou, characterized by low density and a large specific surface area and consists of many loosely related subparticles of a HUNDRED;

Figures 33A and 33B are enlarged image to usually get a HUNDRED, in particular, illustrating that the conventional particle HUNDRED is characterized by a large particle size, lower density and a lower specific surface area in comparison with the particle HUNDRED of the invention of figures 32A and 32V;

Figure 34 is a simplified process flow diagram for a method of obtaining purified terephthalic acid (MOUTH) of the prior art;

Figure 35 is a simplified process flow diagram for a method of obtaining a MOUTH in accordance with one implementation of the present invention.

DETAILED DESCRIPTION

One embodiment of the present invention relates to liquid-phase partial oxidation of oxidizable compounds. This oxidation is preferably carried out in the liquid phase, multi-phase reaction medium contained in one or more reactors with mixing. Suitable reactors with mixing include, for example, reactors with bubbling stirring (for example, a bubble column reactor), the reactor with mechanical agitation (e.g., capacitive reactors with continuous the m mixing) and reactors with mixing flow (for example, jet reactors). In one embodiment, the implementation of liquid-phase oxidation is carried out in one bubbling reactor column.

In accordance with the usage in this document the term "bubble column reactor" shall mean the reactor is designed to facilitate chemical reactions in multiphase reaction medium, where mixing of the reaction medium is mainly provided in the moving gas bubbles upward through the reaction medium. In accordance with the usage in this document, the term "mixing" shall mean the work required in the reaction medium, which leads to a flow and/or mixing of the fluid. In accordance with the usage in this document, the terms "main part", "mainly" and "primarily" shall mean more than 50 percent. In accordance with the usage in this document, the term "mechanical agitation" shall mean the mixing of the reaction medium caused by the physical movement of a rigid or flexible elements (element) relative to the reaction medium or inside of the reaction mass. For example, mechanical mixing can be ensured when using rotation, oscillation and/or vibration of the internal agitators, paddles, vibrators and the acoustic diaphragms, located in the reaction medium. In accordance with the usage in this document, the term "mixing flow" shall mean the mixing of the reaction medium caused by high-speed injectionem and/or recirculation of one or more of the fluid in the reaction medium. For example, the mixing flow can be ensured when using nozzles, ejectors and/or Doctorow.

In a preferred implementation of the present invention is less than about 40 percent of the value of the mixing of the reaction medium in a bubbling reactor column during oxidation provide the result of mechanical mixing and/or mixing of the stream, more preferably less than about 20 percent of the value of mixing ensures that the result of mechanical mixing and/or mixing of the flow, and most preferably less than approximately 5 percent of the value of mixing ensures that the result of mechanical mixing and/or mixing flow. Preferably the amount of mechanical mixing and/or mixing a stream attached to a multiphase reaction medium during the oxidation, is less than approximately 3 kilowatts per cubic meter of reaction with the food, more preferably less than approximately 2 kilowatts per cubic meter, and most preferably less than 1 kilowatt per cubic meter.

If we turn now to the figure 1, we can say that there is illustrated a preferred bubble column reactor 20, which includes the shell of the vessel 22, which includes a reaction section 24 and the section of the compartment 26. The reaction section 24 defines an inner reaction zone 28, while section division 26 defines an inner separation zone 30. The flow is predominantly liquid source feed material is introduced into the reaction zone 28 via the inlet openings for the source feed material 32A, b, c, d. The flow is predominantly gas-phase oxidant is injected into the reaction zone 28 through the bubbler oxidizer 34 located in the lower part of the reaction zone 28. The flow of liquid source material supplied and the flow of gas-phase oxidant together form a multiphase reaction medium 36 within the reaction zone 28. Multiphase reaction medium 36 includes a liquid phase and a gas phase. More preferably multiphase reaction medium 36 includes a three-phase environment, including solid-phase, liquid-phase and gas-phase components. Solid-phase component of the reaction medium 36 is preferably precipitates within the reaction zone 28 in the PR is walking oxidation reaction, carried out in the liquid phase of reaction medium 36. Bubble column reactor 20 includes a discharge outlet for the suspension 38, located near the bottom of the reaction column 28, and an outlet for gas 40, located near the top of the zone of separation 30. The exhaust flow of the suspension, including liquid-phase and solid-phase components of the reaction medium 36, is withdrawn from the reaction zone 28 through the exhaust hole for suspension 38, while the exhaust stream is predominantly gas is withdrawn from the zone compartment 30 through the outlet for gas 40.

The flow of the liquid source feed material introduced into bubbling reactor column 20 through the inlet to the original feed material 32A, b, c, d, preferably includes an oxidizable compound, the solvent and the catalyst.

Oxidizable compound present in the flow of the liquid source feed material, preferably has at least one hydrocarbonous group. More preferably, the oxidizable compound is an aromatic compound. Even more preferably, the oxidizable compound is an aromatic compound having at least one attached hydrocarbonous group or at least one substituted attached hydrocarbon the ing group or containing, at least one attached heteroatom or at least one attached carboxylic acid functionality (-COOH). Even more preferably, the oxidizable compound is an aromatic compound having at least one attached hydrocarbonous group or at least one substituted attached hydrocarbonous group, each attached group contains from 1 to 5 carbon atoms. And even more preferably oxidizable compound is an aromatic compound having no more, no less than two attached groups, each attached group contains no more, no less than one atom of carbon and consists of methyl groups and/or substituted by methyl groups and/or at most one group of carboxylic acid. Even more preferably, the oxidizable compound is a para-xylene, meta-xylene, para-Truelove aldehyde, meta-Truelove aldehyde, para-Truelove acid, meta-Truelove acid and/or acetaldehyde. Most preferably, the oxidizable compound is a para-xylene.

"Gidrolabilna group" in accordance with the definition in this document represents at least one atom of carbon, which is associated with only hydrogen atoms or one is mi carbon atoms. "Substituted gidrolabilna group" in accordance with the definition in this document represents at least one atom of carbon, associated with at least one heteroatom and at least one hydrogen atom. "Heteroatoms" in accordance with the definition in this document represent all atoms other than carbon atoms and hydrogen. Aromatic compounds in accordance with the definition herein include aromatic ring, preferably containing at least 6 carbon atoms, more preferably containing only carbon atoms as part of the ring. Suitable examples of such aromatic rings include, but are not limited to: benzene, biphenylene, terpinolene, naphthalene and other condensed aromatic ring carbon-based.

Suitable examples of oxidizable compounds include aliphatic hydrocarbons (e.g. alkanes, branched alkanes, cyclic alkanes, aliphatic alkenes, branched alkenes and cyclic alkenes); aliphatic aldehydes (e.g. acetaldehyde, propionic aldehyde, somerley aldehyde and n-butyric aldehyde); aliphatic alcohols (e.g. ethanol, isopropanol, n-propanol, n-butanol and Isobutanol); aliphatic ketones (e.g. the, dimethylketone, ethylmethylketone, diethylketone and isopropylethylene); aliphatic esters (for example, methylformate, methyl acetate, ethyl acetate); aliphatic peroxides, percolate and hydroperoxides (for example, tert-butylhydroperoxide, peracetic acid, and di-tert-butylhydroperoxide); aliphatic compounds having groups which are combinations of the above-mentioned aliphatic options plus other heteroatoms (e.g., aliphatic compounds containing one or more molecular segments of hydrocarbons, aldehydes, alcohols, ketones, esters, peroxides, perkiset and/or hydroperoxides in combination with sodium, bromine, cobalt, manganese and zirconium); various benzene ring, naphthalene ring, biphenyls, terphenyls, and other aromatic groups having one or more attached hydrocarbonrich groups (for example, toluene, ethylbenzene, isopropylbenzene, n-propylbenzene, neopentylene, para-xylene, meta-xylene, ortho-xylene, all isomers of trimethylbenzenes, all isomers of tetramethylbenzene, pentamethylbenzene, hexamethylbenzene, all isomers of ethylmethylamino, all isomers of diethylbenzene, all isomers of ethyldimethylamine, all isomers of dimethylnaphthalene, all isomers of ethylmethylketone, all isomers of diethylketone, all isomers of dimethylbiphenyl, all somery of ethylmethylamino and all isomers of ditiberio, stilbene and stilbene, having one or more attached hydrocarbonrich groups, fluorene and fluorene having one or more attached hydrocarbonrich groups, anthracene and anthracene having one or more attached hydrocarbonrich groups, and diphenylethan having one or more attached hydrocarbonrich groups); various benzene ring, naphthalene ring, biphenyls, terphenyls, and other aromatic groups having one or more attached hydrocarbonrich groups and/or containing one or more attached heteroatoms, which can combine with other atoms or groups of atoms (e.g., phenol, all isomers of METHYLPHENOL, all isomers dimethylphenol, all isomers napolov, simple benzylmethylamine ether, all isomers of bromophenols, Brabanthal, all isomers of brontallo, including alpha broncolor, debrabant, naphtalene cobalt and all isomers of bromobiphenyl); various benzene ring, naphthalene ring, biphenyls, terphenyls, and other aromatic groups having one or more attached hydrocarbonrich groups and/or containing one or more attached heteroatoms, and/or having one or more attached substituted hydrocarbonrich groups (e.g., benzaldehyde, all isomers of bromobenzaldehyde, all isomers b is mirovnih Truelove aldehydes, including all isomers of alpha-bromeliae aldehydes, all isomers of hydroxybenzaldehyde, all isomers of bromhidrosisbacterial, all isomers of benzodioxolyl, all isomers of benzotrichloride, para-Truelove aldehyde, meta-Truelove aldehyde, ortho-Truelove aldehyde, all isomers of colordialog1.showdialog, all isomers of toluoldiisocyanates, all isomers of colormatrixfilter, all isomers of dimethylaminobenzaldehyde, all isomers of dimethylaminobenzaldehyde, all isomers of dimethylaminobenzaldehyde, all isomers of trimethylbenzaldehyde, all isomers of ethyltoluene, all isomers of trimethylbenzaldehyde, tetramethyldisiloxane, hydroxymethylbenzene, all isomers of hydroxymethylcellulose, all isomers of hydroxymethylbutyrate, all isomers hydroxymethylcellulose aldehydes, all isomers hydroxymethylbutyrate aldehydes, benzylhydroxylamine benzoylperoxide, all isomers of trimethylhydrazine and all isomers of methylphenyldichlorosilane); various benzene ring, naphthalene ring, biphenyls, terphenyls, and other aromatic groups having one or more attached selected groups, and the selected group are gidrolabilna group and/or p is soedinenie heteroatoms, and/or substituted gidrolabilna groups, groups and/or carboxylic acid groups and/or peroxyacids (e.g., benzoic acid, para-tolarova acid, meta-tolarova acid, ortho-tolarova acid, all isomers ethylbenzene acids, all isomers propylbenzene acids, all isomers butylbenzoic acids, all isomers pentylbenzoic acids, all isomers dimethylbenzoic acids, all isomers ethylmethylamine acids, all isomers trimethylbenzoic acids, all isomers tetramethylbenzene acids, pentamethylbenzene acid, all isomers diethylbenzene acids, all isomers benzylcarbamoyl acids, all isomers benzotriazole acids, all isomers methylbenzeneboronic acids, all isomers dimethylphenylcarbinol acids, all isomers methylbenzotriazole acids, all isomers brombenzoic acids, all isomers dibromobenzoic acids, all isomers bromeliae acids, including alpha-Bromeliaceae acid, trilocana acid, all isomers of hydroxybenzoic acids, all isomers hydroxymethylbenzene acids, all isomers hydroxytoluene acids, all isomers hydroxymethylcellulose acids, all isomers hydroxyethylmethylcellulose acids, all isomers hydroxypropanoic acids, all isomers hydroxyprolisilane acids, all isomers hydroxymethylpropane eunuch acids, all isomers of carboxybenzaldehydes, all isomers of dicarboxaldehyde, derbentina acid, all isomers hydroperoxidation acids, all isomers hydroperoxidation acids, all isomers hydroperoxidation acids, all isomers of hydroperoxyalkyl, all isomers methylpiperidino acids, all isomers dimethylphenylcarbinol acids, all isomers methylpiperidino acids, all isomers biphenyldicarboxylic acids, all isomers of stilbene, having one or more attached selected groups, all isomers of fluorenone having one or more attached selected groups, all isomers naphthalene having one or more attached selected groups, benzyl, and all isomers of benzyl having one or more attached selected groups, benzophenone, all isomers of benzophenone having one or more attached selected groups, anthraquinone, all isomers of anthraquinone with one or more attached selected groups, all isomers of diphenylethane having one or more attached selected groups, benzocoumarin and all isomers of benzocoumarin having one or more attached selected groups).

If oxidizable compound present in the stream of liquid source material supplied, Bud is t to be a connection, solid under normal conditions (i.e. solid at standard temperature and pressure), then it is preferred that when introduced into the reaction zone 28 oxidizable compound would be essentially dissolved in the solvent. It is preferable that the boiling point of oxidizable compounds at atmospheric pressure would be equal to at least about 50°C. More preferably the boiling point of oxidizable compounds is in the range from about 80 to about 400°C., and most preferably in the range from 125 to 155°C. the Amount of oxidizable compounds present in the liquid source feed material, preferably is in the range from about 2 to about 40 weight percent, more preferably in the range of from about 4 to about 20 weight percent, and most preferably in the range from 6 to 15 mass percent.

At the moment, it should be noted that the oxidizable compound present in the liquid source feed material can include a combination of two or more different oxidizable reactants. The data flow of two or more different chemicals can be when mixed in the flow of the liquid source material supplied, or it can be done with their section of the Institute on several threads of the original feed material. For example, oxidizable compound comprising para-xylene, meta-xylene, para-Truelove aldehyde, para-Truelove acid and acetaldehyde, can be fed into the reactor through a single inlet or several separate inlet ports.

The solvent present in the liquid-phase flow of the original feed material, preferably includes an acid component and water component. The solvent is preferably present in the flow of the liquid source feed material with a concentration in the range of from about 60 to about 98 weight percent, more preferably in the range of from about 80 to about 96 weight percent, and most preferably in the range of from 85 to 94 mass%. The acid component of the solvent preferably is a mainly organic low molecular weight monocarboxylic acid containing 1-6 carbon atoms, more preferably 2 carbon atoms. Most preferably the acid component of the solvent is a mainly acetic acid. Preferably the acid component comprises at least about 75 weight percent solvent, more preferably at least about 80 weight percent solvent, and the pre is respectfully from 85 to 98 weight percent of the solvent, when this balance is dominated by water. The solvent is introduced into bubbling reactor column 20 may contain small amounts of impurities, such as, for example, para-Truelove aldehyde, terephthalic aldehyde, 4-carboxybenzene (4-CBA), benzoic acid, para-tolarova acid, para-Truelove aldehyde, alpha-bromo-para-tolarova acid, isophthalic acid, phthalic acid, trimellitate acid, polyaromatic and/or suspended dispersed material. Is preferred that the total amount of impurities in the solvent introduced into bubbling reactor column 20 would be less than about 3 weight percent.

The catalyst is present in the flow of the liquid source feed material, preferably a homogeneous liquid-phase catalyst capable of promoting the passage of oxidation (including partial oxidation) of oxidizable compounds. More preferably the catalyst comprises at least one multivalent transition metal. Even more preferably multivalent transition metal comprises cobalt. Even more preferably the catalyst comprises cobalt and bromine. Most preferably, the catalyst comprises cobalt, bromine and manganese.

In the case of risotti in the catalyst of cobalt is preferred that the amount of cobalt present in the flow of the liquid source feed material would be such that the cobalt concentration in the liquid phase of reaction medium 36 was maintained would be in the range of from about 300 to about 6000 mass parts per million parts (h/mn (wt)), more preferably in the range of from approximately 700 to approximately 4200 hours/mn (wt.), and most preferably in the range from 1200 to 3000 h/mn (wt.). In the case of the presence of a catalyst bromine is preferred that the amount of bromine present in the flow of the liquid source feed material would be such that the concentration of bromine in the liquid phase of reaction medium 36 was maintained would be in the range of from about 300 to about 5000 h/mn (wt.), more preferably in the range of from about 600 to about 4000 h/mn (wt.), and most preferably in the range from 900 to 3000 h/mn (wt.). In the case of the presence of a catalyst of manganese is preferred that the amount of manganese present in the flow of the liquid source feed material would be such that the manganese concentration in the liquid phase of reaction medium 36 was maintained would be in the range of from about 20 to about 1000 h/mn (wt.), more preferably in the range of from about 40 to the roughly 500 hours/mn (wt.), most preferably in the range from 50 to 200 h/mn (wt.).

Concentrations of cobalt, bromine and/or manganese in the liquid phase of reaction medium 36, shown above, is expressed as srednerazmernyh and volumetric average values. In accordance with the usage in this document the term "sredneuralskoj" shall mean the average of at least 10 measurements at equal intervals of time during a continuous period of at least 100 seconds. In accordance with the usage in this document, the term "volumetric average" shall mean the average of at least 10 measurements over homogeneous 3-dimensional intervals around a certain amount.

The mass ratio between cobalt and bromine (:Br) in the catalyst introduced into the reaction zone 28, preferably is in the range from approximately 0.25:1 to about 4:1, more preferably in the range of from about 0.5:1 to about 3:1, and most preferably in the range of from 0.75:1 to 2:1. The mass ratio between cobalt and manganese (Co:Mn) in the catalyst introduced into the reaction zone 28, preferably is in the range from approximately 0.3:1 to about 40:1, more preferably in the range of from about 5:1 to AP is sustained fashion 30:1, and most preferably in the range of from 10:1 to 25:1.

The flow of the liquid source feed material introduced into bubbling reactor column 20 may contain small amounts of impurities, such as, for example, toluene, ethylbenzene, para-Truelove aldehyde, terephthalic aldehyde, 4-carboxybenzene (4-CBA), benzoic acid, para-tolarova acid, para-Truelove aldehyde, alpha-bromo-para-tolarova acid, isophthalic acid, phthalic acid, trimellitate acid, polyaromatic and/or suspended dispersed material. In the case of bubble column reactor 20 to obtain terephthalic acid, meta-xylene and ortho-xylene are also considered as impurities. Is preferred that the total amount of impurities in the flow of the liquid source feed material introduced into bubbling reactor column 20 would be less than about 3 weight percent.

Although figure 1 illustrates the embodiment in which the oxidizable compound, the solvent and the catalyst are mixed with each other and injected into the bubbling reactor column 20 in the form of a single thread of the original feed material, in alternative implementations of the present invention oxidizable compound, solvent and catalyst can be introduced in a bubble reactor column 20 separately. For example, the flow of pure para-xylene can be served in a bubbling reactor column 20 through a separate inlet, and not through the inlet opening (s) for solvent and catalyst.

The flow is predominantly gas-phase oxidant introduced into bubbling reactor column 20 through the bubbler oxidizer 34 includes molecular oxygen (O2). Preferably the oxidant stream comprises molecular oxygen in a quantity in the range of from about 5 to about 40 mole percent, more preferably molecular oxygen in a quantity in the range of from about 15 to about 30 mole percent, and most preferably molecular oxygen in a quantity in the range from 18 to 24 mole percent. Is preferred to balance the flow of oxidant mainly would be the gas or gases, such as nitrogen, which is inert to oxidation. More preferably the flow of the oxidizer consists essentially of molecular oxygen and nitrogen. Most preferably, the oxidant stream is a dry air, which contains about 21 mole percent molecular oxygen and nitrogen in the range of from about 78 to about 81 mole percent. In alternative implementations of this image is placed to the flow of oxidant may include essentially pure oxygen.

If we refer again to figure 1, we can say that bubbling reactor column 20 is preferably equipped with a valve protection irrigation 42 located above the upper surface 44 of the reaction medium 36. The dispenser medium irrigation 42 may function in such a way as to enter the drops flow primarily liquid-phase medium irrigation in the separation zone 30 using any tools drop-known state of the art. More preferably the dispenser medium irrigation 42 produces spray droplets downward toward the upper surface 44 of the reaction medium 36. Preferably the spray droplets in the direction of top-down influences (i.e. spread and impact)of at least approximately 50 percent of the maximum area of a horizontal cross-sectional area of the compartment 30. More preferably, the spray of droplets having an impact, at least about 75 percent of the maximum area of a horizontal cross-sectional area of the compartment 30. Most preferably, the spray of droplets having an impact, at least 90 percent of the maximum area of a horizontal cross-sectional area of the compartment 30. This dispersion liquid medium irrigation in the direction from the above down can help prevent foaming at or above the upper surface 44 of the reaction medium 36, and can also contribute to the separation of any liquid droplets or suspension, captured in the moving bottom-up gas, which moves in the direction of the outlet openings for gas 40. In addition, the liquid medium irrigation can be used to reduce the amount of dispersed material and potentially precipitating compounds (for example, dissolved benzoic acid, para-Truelove acid, 4-CBA, terephthalic acid and a metal salt catalyst), leaving with the exhaust gas stream taken from the zone of separation 30 through the outlet for gas 40. In addition, as a result of the distillation of the introduction of drops of medium irrigation in the separation zone 30 can be used to regulate the composition of the exhaust gas stream taken from the outlet of the gas 40.

The flow of liquid medium irrigation entered into the bubbling reactor column 20 through the dispenser medium irrigation 42, preferably has approximately the same composition, as formed by the solvent flow component liquid source feed material introduced into bubbling reactor column 20 through the inlet to the original feed material 32A, b, c, d. Thus, it is preferred that the flow of liquid medium irrigation would contain an acid component and water. Acid to the ponent of flow irrigation preferably is a low molecular weight organic monocarboxylic acid, containing 1-6 carbon atoms, more preferably 2 carbon atoms. Most preferably the acid component of flow irrigation is an acetic acid. Preferably the acid component comprises at least about 75 weight percent of flow irrigation, more preferably at least about 80 weight percent of flow irrigation, and most preferably from 85 to 98 weight percent of flow irrigation, and the balance is water. Because the flow of irrigation usually has essentially the same composition as the solvent in a stream of liquid source feed material, then, when this description will refer to "total solvent introduced into the reactor, such "total solvent" shall include both the flow of irrigation and formed by the solvent part of the flow of the original feed material.

During liquid-phase oxidation in a bubbling reactor column 20 is preferred that the threads of the original feed material, oxidizer and medium irrigation in the reaction zone 28 is essentially continuously be introduced, while the exhaust gas flows and suspensions from the reaction zone 28 is essentially continuously'd selected. In accordance with the use herein of the term "beings who continuously" shall mean the period, at least 10 hours with breaks lasting less than 10 minutes. Is preferred that during the oxidation of the oxidizable compound (e.g., para-xylene) essentially continuously introduced into the reaction zone 28 at a flow rate equal to at least about 8000 pounds per hour, more preferably at a flow rate in the range from about 13000 to approximately 80000 pounds per hour, even more preferably in the range of from about 18000 to approximately 50,000 pounds per hour, and most preferably in the range of 22,000 to 30,000 pounds per hour. Despite the fact that in the General case, it is preferable that the costs of the incoming flows of the original feed material, oxidizer and medium irrigation essentially would be stationary at the moment, it should be noted that one embodiment of the present invention provides a surge of incoming flow of the original feed material, oxidizer and/or the environment irrigation in order to improve the passage of mixing and mass transfer. In the case of the introduction of the incoming flow of the original feed material, oxidizer and/or medium irrigation in the pulsing mode is preferred that their costs ranged would range from approximately 0 to approximately 500 percent from referenced herein article is transient expenses more preferably in the range from approximately 30 to approximately 200 percent of the referenced herein fixed costs, and most preferably in the range from 80 to 120 percent of the referenced herein fixed costs.

The average reaction rate in one pass per unit of time (STR) in a bubbling reactor oxidizing column 20 is defined as the mass of oxidizable compound applied per unit volume of reaction medium 36 per unit time (for example, pounds of para-xylene fed to one cubic meter per hour). In normal use, the amount of oxidizable compounds not converted into a product that normally would subtract from the amount of oxidizable compounds in the stream of the original feed material before calculating the value of STR. However, for many oxidizable compounds, preferred herein (e.g., para-xylene), the degree of conversion and outputs are normally high, and in this document this term is convenient to define as stated above. Among other things, for reasons related to capital expenditure and working fill factor, in the General case is preferred that the reaction was carried out under high STR value. However, carrying out the reaction at a much higher STR can have effect the quality or the output of the partial oxidation. Bubble column reactor 20 is particularly suitable for use when the STR value for oxidizable compound (e.g., para-xylene) is in the range from about 25 kilograms per cubic meter per hour to about 400 kilograms per cubic meter per hour, more preferably in the range of from about 30 kilograms per cubic meter per hour to approximately 250 kilograms per cubic meter per hour, even more preferably from about 35 kilograms per cubic meter per hour to about 150 kilograms per cubic meter per hour, and most preferably in the range from 40 kilograms per cubic meter per hour to 100 kilograms per cubic meter per hour.

The STR value for oxygen in the bubble reactor column 20 is defined as the molecular mass of oxygen consumed per unit volume of reaction medium 36 per unit time (for example, the molecular weight of oxygen consumed per cubic meter per hour). Among other things, for reasons related to capital expenditure and expenditure of solvent during the oxidation, in the General case is preferred that the reaction was carried out under high STR value for oxygen. However, carrying out the reaction at a much higher STR for KIS is orodo ultimately leads to deterioration of the quality or output of the partial oxidation. Wrong bind themselves by theory, it appears that this is possible is due to the transfer rate of molecular oxygen from the gas phase into the liquid on the area of the interfacial surface and, consequently, the volume of liquid. Excessively high value STR oxygen may lead to an excessively low level of dissolved oxygen in the liquid phase reaction medium.

The value of the global average STR oxygen in this document is defined as the mass of the total oxygen consumed in the entire volume of reaction medium 36 per unit time (for example, the molecular weight of oxygen consumed per cubic meter per hour). Bubble column reactor 20 is particularly suitable for use when the value of the global average STR oxygen is in the range from about 25 kilograms per cubic meter per hour to about 400 kilograms per cubic meter per hour, more preferably in the range of from about 30 kilograms per cubic meter per hour to approximately 250 kilograms per cubic meter per hour, even more preferably from about 35 kilograms per cubic meter per hour to about 150 kilograms per cubic meter per hour, and most preferably in the range of from calligrammes on one cubic meter per hour to 100 kilograms per cubic meter per hour.

Is preferred that during oxidation in a bubbling reactor column 20, the ratio between the mass flow of the total solvent of the threads as the original feed material, and environment irrigation) and mass flow oxidizable compounds entering the reaction zone 28, was maintained would be in the range of from about 2:1 to about 50:1, more preferably in the range of from about 5:1 to about 40:1, and most preferably in the range of from 7.5:1 to 25:1. Preferably the ratio between the mass flow of the solvent entered as part of the flow of the original feed material, and the mass flow rate of solvent introduced as part of flow irrigation is kept in a range from about 0.5:1 to level zero flow medium irrigation, more preferably in the range of from about 0.5:1 to about 4:1, even more preferably in the range of from about 1:1 to about 2:1, and most preferably in the range of from 1.25:1 to 1.5:1.

Is preferred that during liquid-phase oxidation in a bubbling reactor column 20, the flow of oxidant introduced would be in a bubble reactor column 20 in number, which provides some extra amount of molecular oxygen in comparison with the stoichiometric what potrebnostey oxygen. The amount of excess molecular oxygen required for achieving the best results for a particular oxidizable compounds, has an impact on overall economic performance liquid-phase oxidation. Is preferred that during liquid-phase oxidation in a bubbling reactor column 20, the ratio between the mass flow rate of the oxidizer mass flow oxidizable organic compounds (e.g., para-xylene)entering the reactor 20, was maintained would be in the range of from about 0.5:1 to about 20:1, more preferably in the range of from about 1:1 to about 10:1, and most preferably in the range of from 2:1 to 6:1.

If we refer again to figure 1, we can say that the threads of the original feed material, oxidizer and medium irrigation entered into the bubbling reactor column 20 together form at least part of a multiphase reaction medium 36. The reaction medium 36 is preferably a three-phase environment, including solid phase, liquid phase and gas phase. As mentioned above, oxidation of the oxidizable compound (e.g., para-xylene) occurs mainly in the liquid phase of reaction medium 36. Thus, the liquid phase of reaction medium 36 contains dissolved oxygen and oxidizable compound. Ectotherm the economic nature of the oxidation reaction, which flows in the bubble reactor column 20, causes the boiling/evaporation of part of the solvent (for example, acetic acid and water), introduced through the inlet to the original feed material 32A, b, c, d. Thus, the gas phase reaction medium 36 in the reactor 20 is formed mainly from the evaporated solvent and undissolved and unreacted part of the flow of oxidizer. Certain oxidation reactors of the prior art use of heat-exchange tubes/fins for heating or cooling the reaction medium. However, such a heat-exchange structure may be desirable in the reactor and the method of the invention described herein. Thus, it is preferred to bubble column reactor 20 is essentially not include surfaces that are in contact with the reaction medium 36 and demonstrate srednekraevoy heat flow density in excess of 30,000 watts per square meter.

The concentration of dissolved oxygen in the liquid phase of reaction medium 36 forms a dynamic equilibrium between the rate of mass transfer from the gas phase and the consumption rate due to the reaction in the liquid phase (i.e. it is not simply set the partial pressure of molecular oxygen in the incoming gas phase, Ho whom I was one factor in the rate of supply of dissolved oxygen, and he actually has an effect on the upper limit of the concentration of dissolved oxygen). The amount of dissolved oxygen varies locally, it will be higher close to the interfacial surfaces of the bubbles. In General, the amount of dissolved oxygen depends on the balance between the factors of supply and demand in different parts of reaction medium 36. In time the amount of dissolved oxygen depends on the homogeneity of mixing gas and liquid relative to the rates of chemical consumption. When designing for achieving a good match between supply and demand in relation to dissolved oxygen in the liquid phase of reaction medium 36, it is preferable to Sredneuralskaya and volumetric average oxygen concentration in the liquid phase of reaction medium 36 was maintained at greater than approximately 1 h/m (mol.), more preferably in the range from approximately 4 to approximately 1000 h/m (mol.), even more preferably in the range of from about 8 to about 500 h/m (mol.), and most preferably in the range from 12 to 120 h/m (mol.).

The reaction liquid-phase oxidation is carried out in a bubbling reactor column 20, preferably represents a reaction deposition, which produces TV is RDA phase. More preferably, the liquid-phase oxidation is carried out in a bubbling reactor column 20, leads to the fact that a solid connection (for example, particles of raw crude terephthalic acid in the reaction medium 36 is to form at least about 10 mass percent of the oxidizable compound (e.g., para-xylene), injected into the reaction zone 28. Even more preferably, the liquid-phase oxidation leads to the fact that the solid compound in the reaction medium 36 will form, at least about 50 mass percent of the oxidizable compound. Most preferably the liquid-phase oxidation leads to the fact that the solid compound in the reaction medium 36 will form, at least 90 mass percent of the oxidizable compound. Is preferred that the total amount of solid phase in the reaction medium 36 would have been more than about 3 weight percent when expression through srednerazmernye and volumetric average values. More preferably the total amount of solid phase in the reaction medium 36 is kept in the range from about 5 to about 40 weight percent, even more preferably in the range of from about 10 to about 35 weight percent, and most preferably in the range of from 15 to 30 mass percent. Predpochitays is, to a substantial portion of the oxidation product (e.g., terephthalic acid), resulting in bubbling reactor column 20, exist in the reaction medium 36 in the form of a solid phase as opposed to substance, the remaining dissolved in the liquid phase of reaction medium 36. The number of solid-phase oxidation product present in the reaction medium 36, is preferably at least about 25 weight percent of the total (solid and liquid) of the oxidation product in the reaction medium 36, more preferably at least about 75 weight percent of the total oxidation product in the reaction medium 36, and most preferably at least 95 weight percent of the total oxidation product in the reaction medium 36. Numerical ranges given above for the quantity of the solid phase in the reaction medium 36, are used for essentially stationary regime in bubble columns 20 for essentially continuous period of time, not to start, stop, or not quite optimal functioning in bubble column reactor 20. The amount of solid phase in the reaction medium 36 determined using gravimetric method. In this gravimetric method, representative part of the suspension otber the Ute from the reaction medium and weighed. In terms that effectively provide for keeping the total separation of solid and liquid phases flowing in the reaction medium, free liquid from the part formed by the solid phase, effectively remove when using sedimentation or filtration, without loss of precipitated solid phase and persisting in part, formed by the solid phase, less than about 10 percent of the original mass of the liquid. The remaining liquid in the solid phase effectively evaporated to dryness without sublimation of the solid phase. The remaining part is formed by solid phase weighed. The relationship between the mass portion formed by the solid phase, and the mass of the original part, formed by the suspension, represents the fraction of the solid phase, usually expressed as a percentage.

The deposition reaction carried out in a bubble reactor column 20, can cause fouling (i.e. the accumulation of deposits of a solid phase) on the surface of certain rigid structures that are in contact with the reaction medium 36. Thus, in one implementation of the present invention is preferred to bubble column reactor 20 in the reaction zone 28 is essentially not include any internal heat exchanger, mixing or dam structures, such as the design, the options would be susceptible to fouling. If in the reaction zone 28 will be present interior design, then it would be desirable to avoid the presence of internal structures having outer surfaces that are characterized by a significant amount of space uppermost planar surfaces, such as upward planar surface would be highly susceptible to the occurrence of fouling. Thus, if the reaction zone 28 will be any interior design, it is then preferred that essentially planar surfaces inclined at an angle less than approximately 15 degrees from horizontal, would have been formed in less than about 20 percent of the total surface area of upward exposed external surfaces of such internal structures.

If we refer again to figure 1, we can say that the physical configuration of the bubble column reactor 20 helps to ensure the optimized oxidation of the oxidizable compound (e.g., para-xylene) with a minimum formation of impurities. Is preferred that elongated reaction section 24 of the shell of the tank 22 would include essentially cylindrical main body 46 and bottom plate 48. The top edge of the reaction zone 28 is defined by a horizontal plane 50, passing the th through the top of the cylindrical main body 46. The bottom edge 52 of reaction zone 28 is defined by the lower inner surface of the bottom plate 48. Usually the bottom edge 52 of reaction zone 28 is located near the mouth of the outlet openings for the suspension 38. Thus, elongated reaction zone 28 defined within the bubble column reactor 20 has a maximum length "L"measured from the top edge 50 to the lower edge 52 of reaction zone 28 along the longitudinal axis of the cylindrical main body 46. The length "L" of the reaction zone 28 is preferably in the range from approximately 10 to approximately 100 meters, more preferably in the range of from about 20 to about 75 meters, and most preferably in the range of from 25 to 50 meters. The reaction zone 28 has a maximum diameter (width) "D", which is usually equal to the maximum inner diameter of the cylindrical main body 46. The maximum diameter "D" of the reaction zone 28 is preferably in the range from approximately 1 to approximately 12 meters, more preferably in the range of from about 2 to about 10 meters, more preferably in the range of from about 3.1 to about 9 meters, and most preferably in the range of from 4 to 8 meters. In a preferred implementation of the present invention, the reaction zone 28 is characterized by the ratio DL is t to the diameter "L:D" in the range of from about 6:1 to about 30:1. Even more preferably, the reaction zone 28 is characterized by a ratio of L:D in the range from about 8:1 to about 20:1. Most preferably, the reaction zone 28 is characterized by a ratio of L:D in the range from 9:1 to 15:1.

As discussed above, the reaction zone 28 in bubble column reactor 20 contains a multiphase reaction medium 36. The reaction medium 36 has a lower edge coincident with the bottom edge 52 of reaction zone 28, and an upper edge located at the level of the upper surface 44. The upper surface 44 of the reaction medium 36 is determined by the position along the horizontal plane that passes through the reaction zone 28 in the vertical position, where the contents of the reaction zone 28 is transferred from the gas-phase solid state to the liquid-phase solid state. The upper surface 44 is preferably located in the vertical position, where the local Sredneuralskaya value retention of gas in a thin horizontal share the contents of the reaction zone 28 is 0.9.

The reaction medium 36 has a maximum height "H"measured between its upper and lower edges. The maximum width "W" of the reaction medium 36 is generally equal to the maximum diameter "D" of the cylindrical main body 46. Is preferred that during liquid-phase oxidation in a bubbling reactor column 20 value N withstood least d is apatone from approximately 60 to approximately 120 percent of L, more preferably from about 80 to about 110 percent of L, and most preferably from 85 to 100 percent of L. In the preferred implementation of the present invention, the reaction medium 36 is characterized by the ratio of height to width "H:W, greater than about 3:1. More preferably, the reaction medium 36 is characterized by the ratio H:W in the range from about 7:1 to about 25:1. Even more preferably, the reaction medium 36 is characterized by the ratio H:W in the range from about 8:1 to about 20:1. Most preferably, the reaction medium 36 is characterized by the ratio H:W in the range from 9:1 to 15:1. In one embodiment of the invention L=H and D=W, so that different sizes or ratios presented in this document for L and D, also belong to H and W, and Vice versa.

The relatively high ratio of L:D and H:W provided in accordance with one variant of the invention can contribute in some significant advantages of the system of the invention. As discussed in more detail later, it was found that the higher the ratio L:D and H:W, as well as certain other characteristics, discussed next, can help create a favorable vertical gradients in the concentrations of molecular oxygen and/is whether the oxidizable compound (e.g., para-xylene) in reaction medium 36. In contrast to conventional wisdom, according to which would be best to have a well mixed reaction medium at a relatively uniform concentration throughout the volume, it was found that splitting vertically on the stage in relation to the concentrations of oxygen and/or oxidizable compounds facilitates more effective and efficient completion of the oxidation reaction. To minimize the concentrations of oxygen and oxidizable compounds near the top of reaction medium 36 can help prevent losses of unreacted oxygen and unreacted oxidizable compounds in the ash through the upper outlet for a gas 40. However, if the concentration of oxidizable compounds and unreacted oxygen will be low throughout the volume of reaction medium 36, then the rate and/or selectivity of the oxidation will decrease. Thus, it is preferred that the concentration of molecular oxygen and/or oxidizable compounds would be significantly higher near the bottom of reaction medium 36 in comparison with what takes place near the top of reaction medium 36.

In addition, a high ratio of L:D and H:W lead to the fact that the pressure of the bottom of reaction medium 36 is substantially pre is Yeti pressure of the top of reaction medium 36. This pressure gradient in vertical direction is a consequence of the height and density of the reaction medium 36. One advantage of the presence of this pressure gradient vertically is that the increased pressure of the bottom of the vessel becomes the driving force for achieving greater solubility and mass transfer of oxygen in comparison with what could be achieved in other cases with comparable temperatures and pressures of the top of the reactor in small reactors. Thus, the oxidation reaction can be conducted at lower temperatures in comparison with what would be required in smaller containers. In the case of bubble column reactor 20 for the partial oxidation of para-xylene to obtain crude crude terephthalic acid (CTA) the ability of functioning at low temperatures the reaction under the same or better speeds mass transfer of oxygen allows you to take advantage of several benefits. For example, low-temperature oxidation of para-xylene leads to reduction of quantity of solvent combusted during the passage of the reaction. As discussed in more detail later, low-temperature oxidation also favors the formation of small, characterized by a large specific surface area, loosely is knitted, soluble particles HUNDRED, which can be subjected to more economical methods of treatment in comparison with large, characterized by low specific surface area, particle density HUNDRED, obtained in accordance with commonly used methods of high-temperature oxidation.

Is preferred that during the oxidation reactor 20 srednekraevoy and volumetric average temperature of the reaction medium 36 was passed would be in the range of from about 125 to about 200°C., more preferably in the range of from about 140 to about 180°C., and most preferably in the range of from 150 to 170°C. the Pressure of the top of the reactor above the reaction medium 36 is preferably kept in the range from about 1 to about 20 bar gauge pressure (bar (psig), more preferably in the range of from about 2 to about 12 barg.), and most preferably in the range of from 4 to 8 barg.). Preferably the pressure difference between the top of reaction medium 36 and the bottom of reaction medium 36 is in the range from approximately 0.4 to approximately 5 bar, more preferably the pressure is in the range from about 0.7 to about 3 bar, and most preferably the pressure is in the range from 1 to 2 bar. Though the OC, in the General case, it is preferable that the pressure of the top of the reactor above the reaction medium 36 was maintained at a relatively constant value, one embodiment of the present invention provides for the presence of pressure pulsations of the top of the reactor to facilitate improved through mixing and/or mass transfer in the reaction medium 36. In the case of pressure pulsation of the top of the reactor is preferred that the pressure pulsations would be in the range of from about 60 to about 140 percent from mentioned herein stationary pressure of the top of the reactor, more preferably from about 85 to about 115 percent of mentioned herein stationary pressure of the top of the reactor, and most preferably from 95 to 105 percent of mentioned herein stationary pressure of the top of the reactor.

An additional advantage of a high ratio of L:D to the reaction zone 28 is that it can contribute to the increase in the average consumption per unit of flow section for the reaction medium 36. The terms "flow rate per cross sectional area of flow and the gas flow rate per unit cross section of the stream in accordance with the usage in this document in respect of reaction medium 36 is to indicate a volume of supplies is on the gas phase reaction medium 36 at some level height in the reactor, divided by the square horizontal cross-section of the reactor at this level height. Increased consumption per unit cross section of the stream is reached due to the high ratio of L:D to the reaction zone 28 can facilitate passage of the local mixing and increase the retention of gas in the reaction medium 36. Srednerazmernye costs per unit of flow section for the reaction medium 36 at one quarter of the height, half height and/or three-quarters the height of reaction medium 36 is preferably exceeds about 0.3 meters per second, more preferably in the range from approximately 0.8 to approximately 5 meters per second, more preferably in the range of from about 0.9 to about 4 meters per second, and most preferably in the range of from 1 to 3 meters per second.

If we refer again to figure 1, it can be said that the section of branch 26 of the bubble column reactor 20 is simply extended part of the shell of the tank 22 located directly above the reaction section 24. Section division 26 provides a reduction in the speed of moving up from the bottom of the gas phase in bubble reactor column 20 when the gas phase rises above the upper surface 44 of the reaction medium 36 and close to the outlet for gas 40. This is the reduction of the velocity of the gas phase from the bottom up helps facilitate the removal of liquid and/or solid phases, captured in the flowing bottom-up gas phase, and, thus, leads to a decrease in unwanted loss of certain components present in the liquid phase of reaction medium 36.

Section division 26 preferably includes transitional wall, generally forming surface of a truncated cone, 54, in the General case wide cylindrical side wall 56 and the top plate 58. Narrow bottom edge transition wall 54 connects with the top of the cylindrical main body 46 of the reaction section 24. Wide top edge transition wall 54 connects with the bottom of the wide side wall 56. Is preferred that a transition wall 54 would pass from the bottom up and from the inside out from its narrow bottom edge at an angle in the range from approximately 10 to approximately 70 degrees from the vertical, more preferably in the range of from about 15 to about 50 degrees from the vertical, and most preferably in the range of from 15 to 45 degrees from the vertical. Wide side wall 56 has a maximum diameter "X", which in General is larger than the maximum diameter "D" of the reaction section 24, although, if the upper part of the reaction section 24 will have a smaller diameter in comparison with the total maximum diameter of the reaction section 24, then X can actually be less than D. In predpochtitel the Ohm variant of realization of the present invention, the ratio between the diameter of the wide side walls 56 and maximum diameter of the reaction section 24 "X D" ranges from about 0.8:1 to about 4:1, most preferably in the range of from 1.1:1 to 2:1. The top plate 58 is connected with the top of the wide side wall 56. The top plate 58 preferably is an element in the General case in the form of an elliptical plate defining a Central opening, which makes possible the maintenance of gas from the zone compartment 30 through the outlet for gas 40. In alternative implementations, the upper plate 58 may be of any shape, including conical. The separation zone 30 has a maximum height "Y", measured from the top 50 of the reaction zone 28 of the uppermost part of the zone of separation 30. The ratio between the length of the reaction zone 28 and the height of the zone of separation 30 "L:Y" is preferably in the range from about 2:1 to about 24:1, more preferably in the range of from about 3:1 to about 20:1, and most preferably in the range of from 4:1 to 16:1.

If we turn now to figures 1-5, we can say that will now be discussed in more detail the location and configuration of the bubbler oxidizer 34. Figures 2 and 3 demonstrate that the bubbler oxidizer 34 may include an annular element 60, the transverse element 62 and a pair of channels for input oxidant 64A, b. In a convenient embodiment, the data channels for input oxidant 64A, b can enter into the container at the level of height above the annular element 60, and p is the next to turn down so, as illustrated in figures 2 and 3. In an alternative embodiment, the channel input oxidant 64A, b can enter into the container below the annular element 60, or approximately on the same horizontal plane as the annular element 60. Each channel input oxidant 64A, b includes a first edge connected to the respective inlet for oxidant 66A, b, formed in the shell of the tank 22, and a second edge, through the fluid connecting with the annular element 60. The annular element 60 is preferably formed of channels, more preferably from a variety of straight sections of the channels, and most preferably a multitude of straight pipe sections, rigidly connected with each other with obtaining a tubular polygonal ring. Preferably the annular element 60 is formed, at least 3 straight pipe sections, more preferably from 6-10 pipe sections, and most preferably from 8 pipe sections. Accordingly, if the annular element 60 is formed of 8 pipe sections, then he will have in the General case, octagonal configuration. The transverse element 62 is preferably produced from essentially a straight pipe section, through which the fluid is connected with the opposite pipe sections of the ring element 60 and passes diagonally between them. Pipe is under, used for control element 62 preferably has essentially the same diameter as the pipe sections are used to obtain the annular element 60. It is preferable that the pipe sections, which form channels for input oxidant 64A, b, the annular element 60 and the transverse element 62, would have a nominal diameter greater than about 0.1 m, more preferably in the range from approximately 0.2 to approximately 2 meters, and most preferably in the range from 0.25 to 1 meter. As can best be illustrated in figure 3, each element selected from the annular element 60 and the transverse element 62, is characterized by the presence of many top holes for oxidizer 68 intended for release flow of oxidant from the bottom up in the reaction zone 28. As can be best illustrated in figure 4, the annular element 60 and/or the transverse element 62 may be characterized by the presence of one or more lower openings for oxidant 70 intended for release flow of oxidant from top to bottom in the reaction zone 28. The lower holes for oxidant 70 can also be used for the production of liquid and/or solid phases, which can penetrate the annular element 60 and/or cross member 62. In order to prevent accumulated the e of the solid phase inside the bubbler oxidizer 34, through the bubbler 34 can be continuously or periodically to the bypass flow of fluid to flush any amounts accumulated solid phase.

If we refer again to figures 1-4, we can say that during oxidation in a bubbling reactor column 20 threads oxidant perepuskat through the inlet for oxidant 66A, b channels for input oxidant 64A, b, respectively. After that, the flow of oxidant is transported through the channels for input oxidant 64A, b in the annular element 60. As soon as the oxidant stream received in the annular element 60, the flow of oxidant will be distributed on all the interior volume of the annular element 60 and the cross member 62. Thereafter, the flow of oxidant is displaced from the bubbler oxidizer 34 into the reaction zone 28 through upper and lower holes oxidizer 68, 70 of the annular element 60 and the cross member 62.

The mouth of the upper holes for the oxidizer 68 spaced from one another in the lateral direction and are arranged essentially at the same level in height in the reaction zone 28. Thus, the mouth of the upper holes for the oxidizer 68 in General are on the essentially horizontal plane defined by the top of the bubbler oxidizer 34. The mouth of the lower holes oxidant 70 spaced in the lateral direction from one another and are located on codestone the same level in height in the reaction zone 28. Thus, the mouth of the lower holes oxidant 70 in General are on the essentially horizontal plane defined by the bottom of the bubbler oxidizer 34.

In one implementation of the present invention bubbler oxidizer 34 has at least approximately 20 top holes for oxidizer 68 formed therein. More preferably bubbler oxidizer 34 has formed therein the upper holes of the oxidant in amounts in the range from approximately 40 to approximately 800. Most preferably bubbler oxidizer 34 has formed therein the upper holes oxidizer 68 number in the range from 60 to 400. Bubbler oxidizer 34 preferably has at least about 1 bottom hole oxidizer 70 formed therein. More preferably bubbler oxidizer 34 has formed therein the lower holes for oxidant 70 in number in the range from about 2 to about 40. Most preferably bubbler oxidizer 34 has formed therein the lower holes for oxidant 70 in number in the range from 8 to 20. The ratio of the upper holes for the oxidizer 68 and bottom holes for oxidant 70 in the bubbler oxidizer 34 preferably is in the range from about 2:1 doprinosilo 100:1, more preferably in the range of from about 5:1 to about 25:1, and most preferably in the range of from 8:1 to 15:1. The diameters of substantially all of the upper and lower holes oxidizer 68, 70 preferably are essentially the same, so that the ratio between the volumetric flow rates of the oxidant from the upper and lower openings 68, 70 is essentially the same as the above ratios for the relative quantities of the upper and lower holes oxidizer 68, 70.

Figure 5 illustrates the direction of release of the oxidizer from the top and bottom holes for oxidizer 68, 70. As for the top holes for the oxidizer 68, it is preferred that at least part of the upper holes for the oxidizer 68 would have a production flow of an oxidant at an angle "A" from the vertical. It is preferable that the percentage of the top holes for the oxidizer 68, which is oriented at an angle a to the vertical, would be in the range of from about 30 to about 90 percent, more preferably in the range of from about 50 to about 80 percent, more preferably in the range from 60 to 75 percent, and most preferably would be approximately 67 percent. The angle "A" preferably is in the range from about 5 to about 60 is the radius, more preferably in the range of from approximately 10 to approximately 45 degrees, and most preferably in the range of from 15 to 30 degrees. As for the bottom holes for the oxidizer 70, it is preferred that essentially all of the lower holes oxidizer 70 would lie close to the bottom of the annular element 60 and/or cross member 62. Thus, any number of liquid and/or solid phases, which may unintentionally fall into the bubbler oxidizer 34, can be easily released from the bubbler oxidizer 34 through the bottom holes of the oxidizer 70. Preferably the lower holes for oxidant 70 provide production flow of oxidant from the top down substantially at an angle corresponding to the vertical. For the purposes of this description, the upper hole of the oxidant can be any opening that provides for the issuance of flow of the oxidizer in the General case in the upward direction (i.e. at an angle, measured up from horizontal), and the bottom hole of the oxidant can be any opening that provides for the issuance of flow of the oxidizer in the General case in the downward direction (i.e. the angle measured down from the horizontal).

In many commonly used bubble reactor columns containing multiphase reaction medium, essentially all of the reactions is fair Wednesday, below bubbler oxidant (or other mechanism for introducing a flow of oxidant in the reaction zone), is characterized by a very low amount of gas retention. Known state of the art, "holding gas" is simply the volume fraction of a multiphase environment, which is in the gaseous state. Zone low value retention of gas in the environment can also be called "neurorubine" zones. In many commonly used slurry bubble reactor columns a significant proportion of the total volume of the reaction medium is located below the bubbler oxidant (or other mechanism for introducing a flow of oxidant in the reaction zone). Thus, a significant portion of the reaction medium present in the area of lower typically used in bubble reactor columns, is nearisogenic.

It was found that minimizing the number nearisogenic zones in the reaction medium subjected to oxidation in a bubble reactor column can provide to minimize the formation of certain types of undesirable impurities. Neurorubine zone of the reaction medium contains a relatively small number of bubbles of oxidizing agent. This small volume of bubbles of oxidizing agent leads to a decrease in the number who and molecular oxygen, available for dissolution in the liquid phase reaction medium. Thus, the liquid phase in nearisogenic zone of the reaction medium is characterized by a relatively low concentration of molecular oxygen. Data hypoxic neurorubine zone of the reaction medium have a tendency to promote the passage of undesirable side reactions, instead of the desired oxidation reaction. For example, in the case of partial oxidation of para-xylene with obtaining terephthalic acid insufficient availability of oxygen in the liquid phase reaction medium can lead to the formation of undesirable large amounts of benzoic acid and conjugated aromatic rings, in particular, including in the highest degree undesirable molecules are colored substances, known as fluorenone and anthraquinones.

In accordance with one implementation of the present invention the liquid-phase oxidation is carried out in a bubble reactor column, configured and functioning in such a way as to minimize the volume fraction of the reaction medium, characterized by low values of gas retention. This minimizing of the number nearisogenic zones can be quantitatively described in theoretical separation of the total volume of the reaction medium 2,000 discrete horizontal to the her with the same amount. Except for the top and the bottom horizontal of the shares of each horizontal portion is a discrete volume limited by its lateral sides of the side wall of the reactor and bounded on its upper and lower sides of the imaginary horizontal planes. The upper horizontal portion is limited on the lower side of an imaginary horizontal plane, and on its upper side by the upper surface of the reaction medium. The lower horizontal portion is limited in its upper side an imaginary horizontal plane, and on its bottom side the bottom of the tank. As soon as the reaction medium is theoretically divided by 2,000 discrete horizontal lobes with equal volume, you can determine srednekraevoy and volumetric average size of holding gas for each horizontal lobe. In the case of the use of this method for determining the number nearisogenic zones is preferred that the number of horizontal lobes, characterized sredneuralskoj and volumetric average value retention of gas, the smaller of 0.1 would be a value less than 30, more preferably less 15, even more preferably less 6, even more preferably less 4, and most preferably less 2. It is preferable that the number of horizontal is Olya, characterized by the value of holding gas lesser of 0.2 would be a value less than 80, more preferably less 40, even more preferably less 20, even more preferably less 12, and most preferably less 5. It is preferable that the number of horizontal lobes, characterized by the value of holding gas lesser of 0.3 would be a value less than 120, more preferably less 80, even more preferably less 40, even more preferably less 20, and most preferably less 15.

If we refer again to figures 1 and 2, it was found that the lower the location of the bubbler oxidizer 34 in the reaction zone 28 achieves several advantages, including reducing the number nearisogenic zones in reaction medium 36. Given the height "H" of the reaction medium 36, the length "L" of the reaction zone 28 and maximum diameter "D" of the reaction zone 28 is preferred that the main part (i.e. >50 mass percent) of the stream of oxidizing agent introduced into the reaction zone 28 within approximately 0,N, 0,022L and/or 0,25D from the bottom edge 52 of reaction zone 28. More preferably the bulk of the flow of oxidant injected into the reaction zone 28 within approximately 0,N, 0,018L and/or 0,2D from the bottom edge 52 of reaction zone 28. Most preferably the main part of the flow will oxidize the La is injected into the reaction zone 28 within 0,N, 0,013L and/or 0,15D from the bottom edge 52 of reaction zone 28.

In a variant implementation, illustrated in figure 2, the vertical distance "Y1" between the lower edge 52 of reaction zone 28 and the mouths of the upper holes for the oxidizer 68 bubbler oxidizer 34 is less approximately 0,25N, 0,022L and/or 0,25D, so that essentially the entire flow of the oxidizer is fed into the reaction zone 28 within approximately 0,25N, 0,022L and/or 0,25D from the bottom edge 52 of reaction zone 28. More preferably Y1is less than approximately 0,N, 0,018L and/or 0,2D. Most preferably Y1is less than 0,N, 0,013L and/or 0,15D, but greater than 0,N, 0,004L and/or 0 06D. Figure 2 illustrates the start line of the bend 72 in the position in which the lower edge of the cylindrical main body 46 of the shell of the tank 22 is connected with the upper edge of the elliptical bottom plate 48 of the shell of the tank 22. In an alternative embodiment, the bottom plate 48 may be of any shape, including conical, and the start line of the bend is still defined as the lower edge of the cylindrical main body 46. The vertical distance "Y2" between the start line of the bend 72 and the top of the bubbler oxidizer 34 is preferably at least approximately 0,N, 0,001L and/or 0,01D; more preferably, at least about 0,N, 0,004L and/or 0,05D; athe most preferably, at least, 0,01H, 0,008L and/or 0,1D. The vertical distance "Y3" between the lower edge 52 of reaction zone 28 and the mouths of the lower holes oxidant 70 bubbler oxidizer 34 is preferably less than approximately 0,N, 0,013L and/or 0,15D; more preferably less than about 0,N, 0,01L and/or 0,1D; and most preferably less than 0,01H, 0,008L and/or 0,075D, but greater than 0,N, 0,002L and/or 0,025D.

In a preferred implementation of the present invention holes that allow the release of the oxidant stream and flow of the original feed material in the reaction zone are such a configuration, to (mass) flow rate of the oxidant or the original feed material discharged from the holes, would be directly proportional to the square of the living section of the hole. Thus, for example, if 50 percent of the total surface area of the living section, certain all holes oxidizer will be located within 0,15D from the bottom of the reaction zone, then into the reaction zone in the range of 0,15D from the bottom of the reaction zone will be 50 mass percent of the oxidant stream, and Vice versa.

In addition to the benefits resulting to minimize the number nearisogenic areas (i.e. areas with low value holding gas) into the reaction among the e 36, it was found that the passage of oxidation can be improved as the result of maximizing the value retention of gas for a total reaction medium 36. The reaction medium 36 is preferably characterized sredneuralskoj and volumetric average value retention of gas, equal to at least about 0.4, more preferably in the range from about 0.6 to about 0.9, and most preferably in the range of from 0.65 to 0.85. Some of the physical and operational characteristics of bubble column reactor 20 contribute as discussed above, the high value retention of gas. For example, for a data size of the reactor and flow rate for flow of oxidant high ratio of L:D to the reaction zone 28 results in a smaller diameter, causing an increase in flow rate per cross sectional area of flow in the reaction medium 36, which, in turn, leads to increased retention of gas. In addition, the average retention of gas even for a given constant flow rate per cross sectional area of flow, as is well known, influenced by the actual diameter of the bubble column and the ratio of L:d In addition, the contribution to the increased value of the holding gas contributes to minimize the number nearisogenic areas, particularly in the area of the bottom of the reaction zone 28. In addition, nestabilnosti functioning at a high cost per unit of flow and the quantities of gas retention, described herein, can be influenced by the pressure of the top of the reactor and the mechanical configuration of the bubble column reactor.

In addition, the inventors have identified the importance of the optimized pressure of the top of the reactor to obtain high gas retention and increased mass transfer. It may seem that the operation under reduced pressure the top of the reactor, which reduces the solubility of molecular oxygen in accordance with the action of Henry's law, would have led to a reduction in the rate of mass transfer of molecular oxygen from a gas to a liquid. In the vessel with mechanical stirring this option is normal and occurs because the levels of aeration and mass transfer rate mainly determined by the design of the mixing device and the pressure of the top of the reactor. However, in the case of a bubble column reactor, corresponding to the preferred implementation variant of the present invention, it was revealed how to use negative pressure to the top of the reactor in order to stimulate the activity of a given mass flux of gas-phase oxidant larger volume, causing an increase in flow rate per cross sectional area of flow in the reaction medium 36 and, in turn, leads to increased gas retention and transfer rate m is molecular oxygen.

The establishment of equilibrium between coalescence and fragmentation of bubbles is an extremely complex phenomenon, which, on the one hand, to the emergence of the foaming tendency, which causes a decrease in the velocity of the internal circulation of the liquid phase, and that may require a very, very large zones, and on the other hand, to the emergence of the tendency to have a smaller number of very large bubbles, which leads to reduced retention of gas and low mass transfer rate of flow of the oxidant in the liquid phase. As for the liquid phase, as is known, its composition, density, viscosity and surface tension, among other factors, interact in a very complex manner, resulting in obtaining a very complex results even in the absence of the solid phase. For example, in laboratory studies, researchers have found that reporting and evaluation of results according to the observations, even for simple water-air bubble columns is useful to establish the quality of water - whether it be tap water, distilled water or deionized water. In the case of complex mixtures in the liquid phase and in the case of adding the solid phase, the level of complexity increases. Important for the interaction of the solid phase with the liquid phase and the flow of oxidant in the definition of the AI, what the result will be the characteristics of ozonation and schematic flow with natural convection, among other things, are all parameters selectable from the surface inhomogeneities of the individual particles of the solid phase, the average solid particle size, distribution of particle size, the amount of solid phase in comparison with the number of the liquid phase and the ability of a liquid to moisten the surface of the solid phase.

Thus, the ability of the bubble column reactor to function properly at high costs per unit of flow and high value retention of gas described in this document depends on the proper choice of: (1) the composition of the liquid phase reaction medium; (2) the number and type of precipitated solid phase, where both parameters can be adjusted using the reaction conditions; (3) flow of oxidant fed to the reactor; (4) the pressure of the top of the reactor, which affects the volumetric flow rate of the oxidant, the stability of the bubbles and, through energy balance at the reaction temperature; (5) the reaction temperature, which affects the characteristics of flow properties of precipitated solid phase and the specific volume flow of the oxidizer; and (6) geometry and mechanical parts of the reaction vessel, including : the ratio L:D.

If we refer again to figure 1, we can say that it was discovered that obtain an improved distribution of the oxidizable compound (e.g., para-xylene) in reaction medium 36 can be achieved introducing a flow of liquid source material supplied to the reaction zone 28 in multiple positions, spaced vertically. Preferably the flow of the liquid source feed material is introduced into the reaction zone 28 using at least 3 holes for the original feed material, more preferably at least 4 holes for the original feed material. In accordance with the usage in this document, the term "hole for the source feed material" shall mean a hole through which the flow of liquid source feed material produced in the reaction zone 28 for mixing with the reaction medium 36. Preferred to have at least 2 holes for the source of the feed material would be spaced vertically relative to each other, at least approximately 0,5D, more preferably at least about 1,5D, and most preferably, at least 3D. However, it is preferred that the highest hole for the source feed material defended least vertically from himself the th bottom hole oxidizer not more than approximately 0,N, 0,65L and/or 8D; more preferably no more than approximately 0,5H, 0,4L and/or 5D; and most preferably not more than 0,4H, 0,35L and/or 4D.

Despite the fact that the introduction of a flow of liquid source feed material preferably conducted at several positions vertically, it is also been found that an improved distribution of oxidizable compounds in the reaction medium 36 will be achieved if the bulk of the flow of liquid source material supplied will be entered in the lower half of the reaction medium 36 and/or the reaction zone 28. Preferably in the lower half of the reaction medium 36 and/or the reaction zone 28 is administered at least about 75 mass percent of the flow of liquid source feed material. Most preferably in the lower half of the reaction medium 36 and/or the reaction zone 28 is injected at least 90 mass percent of the flow of liquid source feed material. In addition, it is preferable that at least about 30 weight percent of the flow of the liquid source feed material was introduced into the reaction zone 28 within about 1,5D from the lower vertical positions, where in the reaction zone 28 introducing the oxidant stream. This bottommost position vertically, where the oxidant stream is introduced into the reaction zone 28 is typically located in the region of the bottom of the bubbler oxidant; however, in one preferred implementation of the present invention provides for a wide range of alternative configurations for introducing a flow of oxidant in the reaction zone 28. Preferably, at least about 50 mass percent of the liquid source feed material is injected within approximately 2,5D from the lower vertical positions, where in the reaction zone 28 introducing the oxidant stream. Preferably, at least about 75 mass percent of the flow of liquid source feed material is injected within approximately 5D from the lower vertical positions, where in the reaction zone 28 introducing the oxidant stream.

Each hole for the source feed material determines the living section, through which the release of the original feed material. Is preferred that at least about 30 percent of the total surface area of the living section of all of the intake holes for the source feed material housed within about 1,5D from the lower vertical positions, where in the reaction zone 28 introducing the oxidant stream. Preferably, at least about 50 percent of the total surface area of the living section of all of the intake holes for the source of the feed material have the I within approximately 2,5D from the lowest position vertically where in the reaction zone 28 introducing the oxidant stream. Preferably, at least about 75 percent of the total surface area of the living section of all of the intake holes for the source of the feed material are within about 5D from the lower vertical positions, where in the reaction zone 28 introducing the oxidant stream.

If we refer again to figure 1, we can say that in one implementation of the present invention the inlet to the original feed material 32A, b, c, d are simply a series of holes that are vertically aligned on one side of the shell of the tank 22. These holes are for the original feed material preferably have essentially similar diameters smaller than approximately 7 cm, more preferably in the range from about 0.25 to about 5 centimeters, and most preferably in the range of from 0.4 to 2 inches. Bubbling reactor column 20 is preferably equipped with a system of flow control for flow of liquid source material supplied from each of the holes for the original feed material. Such a system flow control preferably includes a separate valve controlling the flow a, b, c, d for each respective vpusknogo the holes for the original feed material 32A, b, c, d. In addition, it is preferable to bubble column reactor 20 would be equipped with air flow control, which would allow at least part of the flow of liquid source feed material to introduce into the reaction zone 28 at an increased flow rate per cross sectional area of flow in the inlet opening equal to at least about 2 meters per second, more preferably at least about 5 meters per second, more preferably at least about 6 meters per second, and most preferably in the range from 8 to 20 meters second. In accordance with the usage in this document, the term "flow rate per cross sectional area of flow in the inlet hole" means sredneuralskoj volumetric flow rate for the flow of the source material supplied from the hole for the original feed material divided by the square holes for the original feed material. Preferably, at least about 50 weight percent of the flow of the original feed material is introduced into the reaction zone 28 at an increased flow rate per cross sectional area of flow in the inlet hole. Most preferably essentially the entire flow of the source feed material is introduced into the reaction zone 28 at an increased flow rate per cross sectional area of the pot is ka in the inlet hole.

If we turn now to figures 6-7, we can say that they illustrated an alternative system of introduction into the reaction zone 28 of the flow of the liquid source feed material. In this implementation, the flow of the original feed material is introduced into the reaction zone 28 at four different levels in height. At each level height equip the distribution of the original feed material 76A, b, c, d. Each distribution system source feed material 76 includes a primary channel for the source feed material 78 and the collector 80. Each collector 80 provide at least two outlets 82, 84 connected to the respective plug-in channels 86, 88, which pass into the reaction zone 28 of the shell of the tank 22. Each plug-in channel 86, 88 is characterized by the presence of the corresponding holes for the source feed material 87, 89, intended to produce flow of the source material supplied to the reaction zone 28. The holes for the original feed material 87, 89 preferably have essentially similar diameters smaller than approximately 7 cm, more preferably in the range from about 0.25 to about 5 centimeters, and most preferably in the range of from 0.4 to 2 inches. Is preferred that the holes for the original feed material 87, 89 in each distribution system source feed material 76A, b, c, d would be located on a diameter across from each other so that the flow of the original feed material to introduce into the reaction zone 28 in opposite directions. In addition, preferred to reside in diameter toward each other, the holes for the original feed material 86, 88 adjacent distribution systems source feed material 76 would be oriented with the turn angle of 90 degrees relative to each other. During operation the flow of liquid source feed material is loaded into the main channel for the source feed material 78, and then he enters the collector 80. The collector 80 evenly distributes the flow of the source material supplied to the simultaneous introduction from opposite sides of the reactor 20 through the holes for the original feed material 87, 89.

Figure 8 illustrates an alternate configuration, where each distribution system source feed material 76 is equipped bayonet tubes 90, 92, and do not plug the channels 86, 88 (shown in figure 7). Bayonet tubes 90, 92 are held in the reaction zone 28 and include many small holes for the source feed material 94, 96, intended for release liquid-phase source is th feed material in the reaction zone 28. It is preferable that the small holes for the source feed material 94, 96 at bayonet tubes 90, 92 would be essentially the same diameters smaller than about 50 mm, more preferably in the range from about 2 to about 25 millimeters, and most preferably from 4 to 15 mm.

Figures 9-11 illustrate an alternative system of distribution of the original feed material 100. Distribution system source feed material 100 provides an introduction flow of liquid source material supplied through multiple distributed vertically and spaced apart in the lateral direction positions without any need for multiple positions input through the side wall of the bubble column reactor 20. System introduction the original feed material 100 in the General case includes a single channel inlet 102, line 104, a lot of upright distributing pipes 106, the mechanism that creates lateral support 108 and the mechanism that creates the vertical support 110. The channel inlet 102 penetrates through the side wall of the main body 46 of the shell of the tank 22. The channel inlet 102 through the fluid connects with highway 104. Highway 104 distributes the flow of the original feed material coming from the feed inlet 102, between upright distribution pipes 106. Each distribution pipe 106 has a multitude of spaced vertical holes for the source feed material a, b, c, d, intended for release stream of the original feed material in the reaction zone 28. The mechanism that creates the side stand, 108 connects with each distribution pipe 106 and prevents relative lateral movement of distribution pipes 106. The mechanism that creates the vertical support 110 is preferably connected with the mechanism that creates lateral support 108 and the top of the bubbler oxidizer 34. The mechanism that creates the vertical support 110 is essentially prevents vertical movement of the distributing pipes 106 in the reaction zone 28. Is preferred that the holes for the original feed material 112 would be essentially the same diameters smaller than about 50 mm, more preferably in the range from about 2 to about 25 millimeters, and most preferably from 4 to 15 mm. Separation of vertical holes for the source feed material 112 in the distribution system source feed material 100, is illustrated in figures 9-11, may be essentially the same as described above in regard to the system the volumes of distribution of the original feed material figure 1.

It was found that schemes of flow of the reaction medium in many bubbling reactor columns can allow for uneven azimuthal distribution of oxidizable compounds in the reaction medium, particularly when the oxidizable compound is mainly imposed on one side of the reaction medium. In accordance with the usage in this document the term "azimuth" is to indicate the angle or spacing around the circumference of the relatively panostaja the longitudinal axis of the reaction zone. In accordance with the usage in this document to "erect" shall mean being in the range of 45° from the vertical. In one implementation of the present invention the flow of the original feed material containing the oxidizable compound (e.g., para-xylene)in the reaction zone is injected through multiple distributed in azimuth holes for the original feed material. Data posted on the azimuth of the hole for the source of the feed material can contribute to the prevention of occurrence in the reaction medium areas of excessively high and excessively low concentrations of oxidizable compounds. Various systems the introduction of the original feed material, is illustrated in figures 6-11, are examples of systems that can deliver good is it to explode in azimuth for the holes for the original feed material.

If we refer again to figure 7, we can say that in order to obtain quantitative characteristics for the posted in azimuth introducing a flow of liquid source material supplied to the reaction medium, the reaction medium can theoretically be divided into four upright azimuthal quadrant Q1, Q2, Q3, Q4" with approximately equal volume. Data azimuthal quadrants Q1, Q2, Q3, Q4" are determined by a pair of imaginary intersecting perpendicular vertical planes "P1, R2"beyond the maximum vertical size and the maximum radial dimension of the reaction medium. If the reaction medium is contained in a cylindrical tank, then the line of intersection of the imaginary intersecting vertical planes P1, R2will approximately coincide with the vertical center line of the cylinder, and each azimuthal quadrant Q1, Q2, Q3, Q4will represent in the General case, a wedge-shaped vertical volume having a height equal to the height of the reaction medium. It is preferable that a significant portion of oxidizable compounds would be released into the reaction medium through the holes for the original feed material, located at m is re, in two different azimuthal quadrants.

In a preferred implementation of the present invention through the holes for the original feed material, which may be in the same azimuthal quadrant, in the reaction medium produced no more than about 80 mass percent of the oxidizable compound. More preferably, through holes for the original feed material, which may be in the same azimuthal quadrant, in the reaction medium produced no more than about 60 mass percent of the oxidizable compound. Most preferably, through holes for the original feed material, which may be in the same azimuthal quadrant, in the reaction medium produced no more than about 40 mass percent of the oxidizable compound. Data parameters for the azimuthal distribution of oxidizable compounds measured when the azimuthal quadrants will azimuth is oriented so that one of the azimuthal quadrants to produce the maximum possible amount of oxidizable compounds. For example, if the total flow of the original feed material will be produced in the reaction environment through two holes for the original feed material, which will azimuthal visit the ENES from each other at 89 degrees, then for purposes of determining the azimuthal distribution in four azimuthal quadrants 100 mass percent of the flow of the original feed material will be produced in the reaction environment in the same azimuthal quadrant, because the azimuthal quadrants can be azimuthally oriented so that the two holes for the source of the feed material would be located in the same azimuthal quadrant.

In addition to the benefits associated with the proper azimuthal spacing of the holes for the source feed has also been found that in a bubbling reactor column substantial could be also proper radial spacing of the holes for the original feed material. It is preferable that a significant portion of oxidizable compounds introduced into the reaction medium, was released through the holes for the original feed material, which are radially spaced in the direction from the outside inwards from the side wall of the vessel. Thus, in one implementation of the present invention a substantial portion of the oxidizable compound enters the reaction zone through the holes for the original feed material, located in the "preferred radial zone for the source of the feed material, which extends in the direction of the WPI is e inward from the upright side walls, defining the reaction zone.

If we refer again to figure 7, it can be said that the preferred radial area of the original feed material "FZ" may take the form of theoretical upright cylinder, centered in the reaction zone 28 and having an external diameter "DO"0,9D, where "D" represents the diameter of the reaction zone 28. Thus, the external annular space "OA", having a thickness of 0,05D, is defined by the area between the preferred radial area for the source of the feed material FZ and the inner side of the side wall defining the reaction zone 28. It is preferable that through holes for the original feed material located in this outer annular space OA, in the reaction zone 28 was injected least a small amount of oxidizable compounds, or did not enter if at all.

In yet another variant implementation is preferred that a small amount of oxidizable compounds were introduced would be in the center of the reaction zone 28, or there did not enter it at all. Thus, as illustrated in figure 8, the preferred radial area of the original feed material FZ may take the form of theoretical upright annular space, centered in the reaction zone 28, having an outer diameter DO, rawny,9D, and having an inner diameter of DI0,2D. Thus, in this variant implementation of the centre's preferred radial zones for the source feed material FZ "cut out" the inner cylinder IC having a diameter of 0,2D. It is preferable that through holes for the original feed material located in this inner cylinder IC, in the reaction zone 28 was injected least a small amount of oxidizable compounds, or did not enter if at all.

In a preferred implementation of the present invention a substantial portion of the oxidizable compound in a reaction medium 36 is injected through the holes for the original feed material, located in the preferred radial zone for the original feed material, regardless of whether the preferred radial area for the source of the feed material to have a cylindrical or annular shape described above. More preferably, through holes for the original feed material, located in the preferred radial zone for the source of the feed material in the reaction medium 36 are released, at least about 25 mass percent of the oxidizable compound. Even more preferably, through holes for the original feed material, located in the preferred radial is the area for the source of the feed material, in reaction medium 36 release at least about 50 mass percent of the oxidizable compound. Most preferably, through holes for the original feed material, located in the preferred radial zone for the source of the feed material in the reaction medium 36 produce at least 75 mass percent of the oxidizable compound.

Despite the fact that theoretical azimuthal quadrants and theoretical preferred radial area of the original feed material, is illustrated in figures 7 and 8 are described with reference to the flow of liquid source feed material, it was found that the proper azimuthal and radial flow gas-phase oxidant may also provide certain advantages. Thus, in one implementation of the present invention description of the azimuthal and radial distribution of the flow of the liquid source feed material presented above also applies to the way in reaction medium 36 is injected stream of gas-phase oxidant.

If we turn now to figures 12-15, we can say that they illustrated an alternative bubbler oxidant 200, in the General case including a ring element 202 and a couple canelands input oxidizer 204, 206. Bubbler oxidant 200 with figures 12-15 similar to the bubbler oxidizer 34 with figures 1-11 when the following three main differences: (1) bubbler oxidant 200 does not include the diagonal cross member; (2) the upper part of the annular element 202 has no holes for release of oxidant in the upward direction; and (3) bubbler oxidant 200 has far more holes in the lower part of the annular element 202.

As may be best illustrated in figures 14 and 15, the lower part of the ring bubbler oxidant 202 is characterized by the presence of many holes for the oxidizer 208. The holes for the oxidizer 208 preferably are configured such that at least about 1 percent of the total surface area of the living section, certain holes oxidizer 208, is located below the Central line 210 (figure 15) of the ring element 202, where the Central line 210 is located at the level of the height to the midpoint of the volume of the annular element 202. More preferably, at least about 5 percent of the total surface area of the living section, certain all the holes for the oxidizer 208, are located below the Central line 210, in this case, at least approximately 2 percent of the total surface area of the living section is determined by the holes 208, which provide for the issue is to the flow of oxidant in the General case in the downward direction within about 30 degrees from the vertical. Even more preferably, at least about 20 percent of the total surface area of the living section, certain all the holes for the oxidizer 208, are located below the Central line 210, in this case, at least approximately 10 percent of the total surface area of the living section is determined by the holes 208, which provide production flow of oxidant in the General case in the downward direction within 30 degrees from the vertical. Most preferably, at least about 75 percent of the total surface area of the living section, certain all the holes for the oxidizer 208, are located below the Central line 210, in this case, at least approximately 40 percent of the total surface area of the living section is determined by the holes 208, which provide production flow of oxidant in the General case in the downward direction within 30 degrees from the vertical. The share of total living area of the cross section defined by all the holes for the oxidizer 208, which are located above the Central line 210, is preferably less than about 75 percent, more preferably less than about 50 percent, more preferably less than about 25 percent, and most preferably less than 5 percent.

As produced by lusterous on figures 14 and 15, the holes for the oxidizer 208 include holes facing downwards, a and holes oriented at an angle, 208b. Holes facing downwards, a have a configuration providing the output stream of the oxidant in the General case in the downward direction at an angle within about 30 degrees from the vertical, more preferably within about 15 degrees from the vertical, and most preferably within 5 degrees from the vertical. Holes oriented at an angle, 208b have a configuration providing the output stream of the oxidant in the General case, from the inside outwards and downwards at an angle "a", which is in the range from about 15 to about 75 degrees from the vertical, more preferably the angle is in the range from approximately 30 to approximately 60 degrees from the vertical, and most preferably the angle is in the range from 40 to 50 degrees from the vertical.

Is preferred that essentially all of the holes for the oxidizer 208 would have approximately the same diameter. The diameter of the holes for the oxidizer 208 preferably is in the range from about 2 to about 300 mm, more preferably in the range of from about 4 to about 120 millimeters, and most preferably in the range of from 8 to 60 mm the century The total number of holes for the oxidizer 208 in the annular element 202 is chosen in accordance with the criteria of low pressure drop, described in detail hereinafter. Preferably the total number of holes for the oxidizer 208 formed in the annular element 202 is at least about 10, more preferably the total number of holes for the oxidizer 208 has a value in the range from about 20 to about 200, and most preferably the total number of holes for the oxidizer 208 has a value in the range from 40 to 100.

Although figures 12-15 illustrate a very specific configuration of the bubbler oxidant 200, at the moment, it should be noted that to achieve the advantages described herein may be used in a wide range of configurations bubblers oxidant. For example, the bubbler oxidant need not have the configuration of an octagonal ring element, illustrated in figures 12-13. Instead, it is possible to bubbler oxidant would be obtained from any channel configuration (channel flow, which uses multiple spaced holes designed to release the flow of oxidizer. The size, number and direction of release, the character is based on holes in the oxidant channel for the flow, preferably within the above ranges. In addition, the bubbler oxidant preferably has a configuration that enables the azimuthal and radial distribution of molecular oxygen, as described above.

Regardless of the specific configuration of the bubbler oxidant is preferred that the bubbler oxidant would be the physical configuration and would function in accordance with the method, which allows to minimize the pressure drop associated with the release of the flow of oxidant from the channel (channels) to flow through the holes of the oxidant in the reaction zone. This pressure drop is expected in the form of srednerazmernogo static pressure of the oxidant stream within the channel to flow into the inlet holes oxidant 66A, b bubbler oxidant minus sredneuralskoe static pressure in the reaction zone at the level of the height, where half of the oxidant stream is injected above the given position vertically, and half of the oxidant stream enters below this position vertically. In a preferred implementation of the present invention sredneuralskoe the pressure drop associated with the release of the oxidant stream from the bubbler oxidant is less than approximately 0.3 MPa (MPa), more preferably less than priblisitelno,2 MPa, even more preferably less than about 0.1 MPa, and most preferably less than 0.05 MPa. In the preferred conditions for the operation of a bubble column reactor described herein, the pressure of the oxidant stream within the channel (channels) for the flow bubbler oxidant preferably is in the range from about 0.35 to about 1 MPa, more preferably in the range of from about 0.45 to about 0.85 MPa, and most preferably in the range from 0.5 to 0.7 MPa.

As mentioned earlier in regard to the configuration of the bubbler oxidant, is illustrated in figures 2-5, it may be desirable continuous or periodic flushing of the bubbler oxidant fluid (e.g., acetic acid, water and/or para-xylene) to prevent fouling of the bubbler oxidant deposits of a solid phase. In the case of using such a washing liquid is preferred that during at least one period of greater than one minute each day, through the bubbler oxidant and out of the holes for the oxidant was perepustili effective amount of liquid (i.e. not just a small number of drops of liquid, which naturally may be present in the stream oxidize the I). If the bubbler oxidant is continuously or periodically will release the liquid, then it is preferred to sredneuralskoe the ratio between the mass flow rate through the bubbler the oxidizer mass flow rate of molecular oxygen through the bubbler oxidant would be in the range from about 0.05:1 to about 30:1 or in the range of from about 0.1:1 to about 2:1, or even in the range of from 0.2:1 to 1:1.

In one implementation of the present invention, a significant portion of the oxidizable compound (e.g., para-xylene) can be introduced into the reaction zone through the bubbler oxidant. In this configuration, it is preferable that the release of oxidizable compounds and molecular oxygen from the bubbler oxidant would occur through the same hole in the bubbler oxidant. As noted above, the oxidizable compound is typically a liquid at STP. Therefore, in this embodiment, the implementation of the bubbler oxidant it is possible to produce two-phase flow, while the liquid phase will contain oxidizable compound, and the gas phase will contain molecular oxygen. However, you must realize that during the release of the bubbler oxidant, at least a portion of the oxidizable compound can be in the gaseous state. In one implementation, the liquid is ABC, manufactured from bubbler oxidant, predominantly forms the oxidizable compound. In yet another variant implementation of the liquid phase produced from the bubbler oxidant, has essentially the same composition as the stream source feed material described above. If the liquid phase produced from the bubbler oxidant, will have essentially the same composition as the stream source feed material, such liquid phase may contain a solvent and/or the catalyst in amounts and ratios described above in regard to the composition of the flow of the original feed material.

In one implementation of the present invention is preferred to through the bubbler oxidant was injected would at least about 10 weight percent of the total number of oxidizable compounds introduced into the reaction zone, more preferably through a bubbler of oxidant in the reaction zone is administered at least about 40 mass percent of the oxidizable compound, and most preferably through the bubbler oxidant in the reaction zone enter at least 80 mass percent of the oxidizable compound. If the entire quantity or part of oxidizable compounds will be introduced into the reaction zone through the bubbler oxidant, it is preferred that at least about 10 Usovich percent of the total number of molecular oxygen, introduced into the reaction zone, was introduced through the same bubbler oxidant, more preferably at least about 40 mass percent of the oxidizable compound in the reaction zone is injected through the same bubbler oxidant, and most preferably at least 80 mass percent of the oxidizable compound in the reaction zone is injected through the same bubbler oxidant. If the reaction zone through the bubbler oxidant will impose significant proportion of oxidizable compounds, then it is preferred that the bubbler oxidant would be established one or more devices, perceiving temperature (e.g., thermocouples). These temperature sensors can be used as an aid to help to make sure that the temperature of the bubbler oxidant does not become dangerously high.

If we turn now to figures 16-18, we can say that they are illustrated in bubble column reactor 20, including internal deaeration tank 300, located in the area of the bottom of the reaction zone 28 in the vicinity of the outlet for the suspension 38. It was found that during the de-aeration of the reaction medium 36 at a relatively high velocity flow of side reactions leading to the formation of impurities. In accordance with the use in the present the m document, the term "deaeration" shall mean the separation of a gas phase from a multiphase reaction medium. If the reaction medium 36 is vysokolegirovannoj (value holding gas >0,3), then the formation of impurities will be minimal. If the reaction medium 36 is vysokolegirovannoj (value holding gas <0,01), then the formation of impurities will also be minimal. However, if the reaction medium is partially aerated (value holding gas 0.01 to 0.3), then be stimulated by the passage of undesirable side reactions and will produce an increased amount of impurities. Deaerating tank 300 has the purpose of solving this and other problems is to minimize the amount of reaction medium 36 in a partially aerated condition and to minimize the time required for de-aeration of the reaction medium 36. Essentially deaerated suspension obtained from the bottom of the deaeration vessel 300, and it comes from the reactor 20 through the exhaust hole for the suspension 38. Essentially deaerated suspension preferably contains less than about 5 volume percent of the gas phase, more preferably less than about 2 volume percent of the gas phase, and most preferably less than 1 volume percent of the gas phase.

In figure 16 bubble column reactor 20 is illustrated as including a level controller 302 and the valve reg is modeling flow 304. The level regulator 302 and the valve controlling the flow 304 interact, providing the curing reaction medium 36 in the reaction zone 28 is essentially constant height. The level regulator 302 can function as a means of perception of the level height (for example, when using the perception of the level of the pressure difference or the perception of the level using a radioactive probe) to the top surface 44 of the reaction medium 36 and the generation of the control signal 306, forming a response to the level of height for the reaction medium 36. The valve controlling the flow 304 interprets the control signal 306 and regulates the flow of suspension through the channel outlet for the suspension 308. Thus, the flow of the suspension from the outlet slurry 38 can vary in the range from the maximum volumetric flow rate of the suspension (Fmaxthen, when the level height for the reaction medium 36 is excessively high, to the minimum volumetric flow rate of the suspension (Fminthen, when the level height for the reaction medium 36 is excessively low.

In order to remove the solid-phase oxidation products from the reaction zone 28, the part must first be bypassed through the deaerating tank 300. Deaerating tank 300 provides nizkotarifnogo internal volume, to the which allows the gas phase reaction medium 36 in a natural way, rising out of the liquid and solid phases of the reaction medium 36, as liquid and solid phases will flow downwards towards the outlet for the suspension 38. The rise of the gas phase from the liquid and solid phases is called the natural upward lifting force acting on the gas phase in the liquid and solid phases. In the case of the deaeration vessel 300 transition reaction medium 36 from the state of fully aerated phase environment in the state is completely deaerated two-phase suspension is fast and efficient.

If we turn now to figures 17 and 18, we can say that the deaerating tank 300 includes in General upright side wall 308 that defines the deaeration zone 312, limited by it. Preferably the side wall 308 passes from the bottom up within about 30 degrees from the vertical, more preferably within about 10 degrees from the vertical. Most preferably the side wall 308 is essentially vertical. The deaeration zone 312 is separated from the reaction zone 28 and has a height "h" and the diameter "d". The top edge 310 of the side wall 308 is open to accept the reaction medium from the reaction zone 28 into the inner volume 312. The bottom edge of the side wall 308 through the fluid to be linked with the issue is knymi hole for suspension 38 through the transition section 314. In certain cases, such as when the mouth of the outlet openings for the suspension 38 is large, or when the diameter "d" of the side wall 308 is small, the transition section 314 can be eliminated. As can best be illustrated in figure 18, the deaerating tank 300 may also include a flow conditioner 316 located in the deaeration zone 312. The stabilizer stream 316 may be any structure that functions to suppress the formation of vortices as solid and liquid phases will flow downwards in the direction of the outlet for the suspension 38.

In order to achieve adequate separation of the gas phase from the solid and liquid phases in the deaeration vessel 300, perform a careful selection of the height "h" and a square horizontal cross-section of the internal deaeration zone 312. The height "h" and the area of the horizontal cross-sectional internal deaeration zone 312 must achieve sufficient distance and time so that, in the selection of the maximum number of suspension (that is, when the selection of suspension for level Fmaxessentially the entire volume of the gas bubbles could, lifting, out of the solid and liquid phases before the gas bubbles reach the bottom outlet in the deaeration vessel 300. Thus, predpochitau the tsya, to the cross-sectional area of deaeration zone 312 would be such that the maximum speed in the downward direction (Vdfor the liquid and solid phases during the passage of deaeration zone 312 would be substantially less than the natural speed of rise (Vufor bubbles of the gas phase during the passage of the liquid and solid phases. Maximum speed in the downward direction (Vdfor the liquid and solid phases during the passage of deaeration zone 312 is at a maximum volumetric flow of the suspension (Fmax), discussed above. The natural speed of rise (Vufor gas bubbles during the passage of the liquid and solid phases varies depending on the size of the bubbles; however, the natural speed of rise (Vu0,5for gas bubbles with a diameter of 0.5 cm with the passage of the liquid and solid phases can be used as a cutoff value, because essentially the entire volume of the bubble, initially present in the reaction medium 36 will correspond to a value in excess of 0.5 centimeter. Preferably the cross-sectional area of deaeration zone 312 is such that Vdis less than approximately 75 percent of the Vu0,5more preferably Vdis less than approximately 40 percent of the Vu0,5most preferably V dis less than 20 percent of the Vu0,5.

Speed when moving from top to bottom for the liquid and solid phases in the deaeration zone 312 deaeration vessel 300 calculated as the volumetric flow of deaerated slurry through the discharge outlet for the suspension 38 divided by the minimum cross-sectional area of deaeration zone 312. Speed when moving from top to bottom for the liquid and solid phases in the deaeration zone 312 deaeration vessel 300 is preferably less than about 50 centimeters per second, more preferably less than about 30 centimeters per second, and most preferably less than 10 centimeters per second.

At the moment, it should be noted that, although the upright side wall 308 deaeration vessel 300 is illustrated as having a cylindrical configuration, the side wall 308 can include multiple side walls, which form a wide range of configurations (e.g., triangular, square or oval), up until the wall will determine the internal volume, characterized by the necessary amount, the cross-sectional area, the width "d" and height "h". In a preferred implementation of the present invention "d" ranges from about 0.2 to priblizitelen is 2 meters, more preferably in the range of from about 0.3 to about 1.5 meters, and most preferably in the range of from 0.4 to 1.2 meters. In a preferred implementation of the present invention "h" is in the range from about 0.3 meters to about 5 meters, more preferably in the range of from about 0.5 to about 3 meters, and most preferably in the range from 0.75 to 2 meters.

In a preferred implementation of the present invention, the side wall 308 is essentially vertical, so that the area of a horizontal cross section of deaeration zone 312 is essentially constant throughout the height "h" of deaeration zone 312. Preferably the maximum area of a horizontal cross section of deaeration zone 312 is less than about 25 percent of the maximum area of a horizontal cross section of the reaction zone 28. More preferably, the maximum area of a horizontal cross section of deaeration zone 312 is in the range from approximately 0.1 to approximately 10 percent of the maximum area of a horizontal cross section of the reaction zone 28. Most preferably the maximum area of a horizontal cross section of deaeration zone 312 is in the range from 0.25 to 4% of the comrade from the maximum area of a horizontal cross section of the reaction zone 28. Preferably the maximum area of a horizontal cross section of deaeration zone 312 is in the range from about 0.02 to about 3 square meters, more preferably in the range of from about 0.05 to about 2 square meters, and most preferably in the range from 0.1 to 1.2 square meters. The amount of deaeration zone 312 is preferably less than approximately 5 percent of the total volume of reaction medium 36 or the reaction zone 28. More preferably the amount of deaeration zone 312 is in the range from about 0.01 to about 2 percent of the total volume of reaction medium 36 or the reaction zone 28. Most preferably the amount of deaeration zone 312 is in the range from 0.05 to about 1 percent of the total volume of reaction medium 36 or the reaction zone 28. The amount of deaeration zone 312 is preferably less than about 2 cubic meters, more preferably in the range from approximately 0.01 to approximately 1 cubic meter, and most preferably in the range of from 0.05 to 0.5 cubic meters.

If we refer now to figure 19, we can say that it is illustrated in bubble column reactor 20, including external deaeration tank 400. In Dan the second configuration aerated reaction medium 36 is withdrawn from the reaction zone 28 through the hole in the side shell of the vessel 22 elevated location. Selected aerated medium is transported to the outer deaerating tank 400 through the channel outlet 402 to separate the gas phase from the solid and liquid phases. Separated gas phase leaves the deaerating tank 400 through the channel 404, while essentially deaerated suspension leaves the deaerating tank 400 through the channel 406.

In figure 19 the channel outlet 402 shown as being approximately straight, horizontal and orthogonal with respect to the shell of the vessel 22. It's just one convenient configuration; and a channel outlet 402 may be different in any respect provided that it provides a suitable connection bubble column reactor 20 and the external deaeration tank 400. If we turn to the channel 404, we can say that in an appropriate case, this channel is attached to the top or near the top of the deaeration tank 400 in order to resolve the issues of safety associated with pocket stagnating gas containing oxidizable compound and an oxidant. In addition, the channels 402 and 404 in an appropriate case, may include a means of cutting off the flow, such as valves.

If the reaction medium 36 will select from the reactor 20 through the outlet elevated location, as it demonstrated the and figure 19, it is then preferred to bubble column reactor 20 was equipped with a bottom outlet opening 408 in the vicinity of the bottom 52 of reaction zone 28. Bottom outlet 408 and bottom channel 410 attached to it, can be used to reduce the fill factor (i.e. emptying) of the reactor 20 during stops. Preferably one or more bottom outlet holes 408 are provided in the lower one-third of the height of reaction medium 36, more preferably in the bottom one-quarter of reaction medium 36, and most preferably at the lowest point of the reaction zone 28.

In the case of selection of suspension in positions elevated location and deaerating system, shown in figure 19, bottom channel 410 and outlet 408 is not used for selection of the suspension from the reaction zone 28 during oxidation. State of the art it is known that the solid phase has a tendency to settling under gravity in parinamah and nepriemyshami other way parts of the suspension, including in channels with stagnating over. In addition, the settled solid phase (e.g., terephthalic acid) may have a tendency to solidification in the form of large agglomerates due to the continued deposition and/or realignment of crystals. Thus, th is would prevent plugging of the lower channel for the flow 410, part of the deaerated slurry from the bottom of the deaerating tank 400 can be used for continuous or periodic washing of the lower channel 410 during normal operation of the reactor 20. A preferred method of providing such a washing channel 410 suspension is periodic opening of the valve 412 in the channel 410 and allowing part of the deaerated suspension to flow through the channel 410 in the reaction zone 28 through the bottom hole 408. Even when the valve 412 is fully or partially open, only part of the deaerated slurry will flow through the lower channel 410, and then back to the reaction zone 28. The remaining portion of the deaerated suspension, not used for washing the lower channels 410, output through the channel 414 of the reactor 20 for further processing in subsequent stages of the technological scheme (e.g. cleaning).

During normal operation of bubble column reactor 20 for a significant period of time (e.g., >100 hours is preferred that the number of deaerated suspension used for washing the lower channel 410, would be less than 50 mass percent of the total deaerated suspension obtained from the bottom of the deaerating tank 400, more preferably anisou, than about 20 weight percent, and most preferably less than about 5 mass percent. In addition, it is preferable that for a significant period of time, the average mass flow of deaerated suspension used for washing the lower channel 410, would be less than approximately 4 times the average mass flow rate of the oxidizable compound introduced into the reaction zone 28, more preferably less than about 2 times the average mass flow rate of the oxidizable compound introduced into the reaction zone 28, still more preferably less than the average mass flow rate of the oxidizable compound introduced into the reaction zone 28, and most preferably less than 0.5 times the average mass flow rate of the oxidizable compounds introduced into the reaction zone 28.

If we refer again to figure 19, we can say that the deaerating tank 400 includes essentially upright, preferably cylindrical side wall 416 that defines the deaeration zone 418. The deaeration zone 418 has a diameter "d" and height "h". The height "h" is measured as the distance vertically between a position in which aerated the reaction medium enters the deaerating tank 400, and the bottom side wall 416. The height "h", the diameter d, the surface area and volume of the deaeration zone 418 preference is sustained fashion are essentially the same, as what is described above in terms of deaeration zone 312 deaeration vessel 300, illustrated in figures 16-18. In addition, the deaerating tank 400 includes an upper section 420, the resulting extension of the side wall 416 above the deaeration zone 418. The top section 420 deaerating tank 400 may have any height, although preferably it passes upward to the level position or a position above the level of reaction medium 36 in the reaction zone 28. The top section 420 provides that the gas phase would have the space for a proper separation from the liquid and solid phases before leaving the deaerating tank 400 through the channel 404. At the moment, it should be noted that, although the channel 404 is illustrated as returning the separated gas phase in the separation zone of the reactor 20, in an alternative embodiment, the channel 404 can be connected to the shell of the vessel 22 at any level height above the channel of the outlet 402. Optional channel 404 can be connected to the channel outlet openings for gas 40 so that the separated gas phase from the deaeration tank 400 has teamed up with remote flow of vapor of the top of the reactor in the channel 40 and we would go on the next stage of the technological scheme for additional processing.

If we turn now is to figure 20, we can say that it is illustrated in bubble column reactor 20 as including hybrid internal-external deaeration tank 500. In this configuration, the portion of reaction medium 36 is withdrawn from the reaction zone 28 through a relatively large hole elevated location 502 in the side shell of the vessel 22. After that, the selected reaction medium 36 is transported through the knee channel 504 relatively large diameter, and it goes to the top of the deaeration tank 500. In figure 20 the knee channel 504 shown as orthogonal connecting a side wall of the shell of the tank 22 and includes a smooth rotation by an angle of approximately 90 degrees. It's just one convenient configuration; and knee channel 504 may be different in any respect provided that it provides a suitable connection bubble column reactor 20 and the external deaeration vessel 500 as described. In addition, the knee channel 504 in an appropriate case, may include a means of cutting off the flow, such as valves.

In the deaeration tank 500 gas phase moves upward, while the solid and liquid phases move from top to bottom. Moving upwards, the gas phase may re-enroll in the knee channel 504, and then go through the hole 502 back to C is well reaction 28. Thus, in the hole 502 may be a counter-current for flowing reaction medium 36 and separated waste gas. Deaerated suspension leaves the deaerating tank 500 through the channel 506. The deaeration capacity 500 includes essentially upright, preferably cylindrical side wall 508 defining a deaeration zone 510. The deaeration zone 510 has a height "h" and the diameter "d". It is preferable that the hole elevated location 502 and knee channel 504 would have a diameter identical to the diameter "d" of the deaeration zone 510 or exceeding it. The height "h", the diameter d, the surface area and volume of the deaeration zone 510 preferably are essentially the same as that described above in regard to the deaeration zone 312 deaeration vessel 300, illustrated in figures 16-18.

Figures 19 and 20 illustrate an embodiment of the bubble column reactor 20, in which the solid product (for example, raw crude terephthalic acid)obtained in the reaction zone 28, is withdrawn from the reaction zone 28 through the outlet elevated location. Selection aerated reaction medium 36 from a position elevated location above the bottom of the bubble column reactor 20 can help prevent the accumulation and stagnation of bad ariawan the th reaction medium 36 in the area of the bottom 52 of reaction zone 28. In accordance with other aspects of the present invention the concentration of oxygen and oxidizable compound (e.g., para-xylene) in reaction medium 36 near the top of reaction medium 36 are preferably of magnitude smaller than the relevant concentrations near the bottom. Thus, the selection of reaction medium 36 in a position elevated location can increase output by reducing the amount of unreacted reagents, taken out of the reactor 20. In addition, when a bubble column reactor 20 will operate at high STR value and the presence of gradients of chemical composition, described herein, the temperature of the reaction medium 36 will vary considerably in the vertical direction. In such conditions, the temperature of reaction medium 36 will usually have local minima close to the bottom edge and the top edge of the reaction zone 28. Close to the bottom edge of the at least refers to the evaporation of the solvent near the place where produce introduction of the entire amount or part of the oxidant. Near the upper edge of the at least again caused by the evaporation of the solvent, although in this case it is due to a reduction of the pressure inside the reaction medium. In addition to this, the gap between the top and bottom edges may be other local minima every time then when the reaction medium will enter the additional amount of source material supplied or oxidant. Thus, in the interval between the bottom edge and the top edge of the reaction zone 28 are one or more temperature highs, the driving force which is the exothermic heat of oxidation reactions. The selection of reaction medium 36 in a position elevated location at elevated temperature can be especially advantageous when at elevated temperatures will be processing in the subsequent stages of the technological scheme, because reduced energy costs associated with heating a selected environment intended for processing in subsequent stages of the technological scheme.

Thus, in a preferred implementation of the present invention and, in particular, when the processing in the subsequent stages of the technological scheme will be carried out at elevated temperatures, the reaction medium 36 of the bubble column reactor 20 are selected through the exhaust opening (s) elevated location above position (s)in which the reaction zone 28 receives at least 50 mass percent of the flow of liquid source material supplied and/or gas-phase flow is of cisitalia. More preferably the reaction medium 36 of the bubble column reactor 20 are selected through the exhaust opening (s) elevated location above position (s)in which the reaction zone 28 is supplied essentially the entire flow of liquid source material supplied and/or flow of gas-phase oxidant. Preferably through the exhaust opening (s) elevated location selected at least 50 mass% of solid-phase and liquid-phase components selected from the bubble column reactor 20. More preferably through the exhaust opening (s) elevated location selected essentially the entire quantity of solid-phase and liquid-phase components selected from the bubble column reactor 20. Preferably the outlet opening (s) high level layout of the place, at least approximately 1D above the lower edge 52 of reaction zone 28. More preferably the outlet opening (s) elevated locations have at least about 2D above the lower edge 52 of reaction zone 28. Most preferably the outlet opening (s) elevated location feature, at least in 3D above the lower edge 52 of reaction zone 28. When there is a height "H" Rea the operating environment 36 is preferred, to the outlet opening (s) elevated location would be placed vertically between approximately 0,2N and approximately 0,8H, more preferably between approximately 0,3N and approximately 0,7H, and most preferably between 0,4W 0,6N. In addition, it is preferable that the temperature of the reaction medium 36 at the outlet elevated location, leaving the reaction zone 28 at least 1°C would exceed the temperature of the reaction medium 36 at the lower edge 52 of reaction zone 28. More preferably, the temperature of reaction medium 36 at the outlet elevated location, leaving the reaction zone 28 is higher than the temperature of the reaction medium 36 at the lower edge 52 of reaction zone 28 at a value in the range from about 1.5 to about 16°C. Most preferably the temperature of the reaction medium 36 at the outlet elevated location, leaving the reaction zone 28 is higher than the temperature of the reaction medium 36 at the lower edge 52 of reaction zone 28 at a value in the range from 2 to 12°C.

If we turn now to the figure 21, we can say that it is illustrated in bubble column reactor 20, including alternative hybrid deaerating tank 600, located in the area of the bottom of the reactor 20. In this configuration, aerovane reaction medium 36 is withdrawn from the reaction zone 28 through a relatively large hole 602 on the bottom edge 52 of the shell of the tank 22. Hole 602 defines an open top edge of the deaerating tank 600. In the deaeration tank 600 gas phase moves upward at the same time, as solid and liquid phases move from top to bottom. Moving upwards, the gas phase may re-enter the reaction zone 28 through the opening 602. Thus, in the opening 602 may be a counter-current for flowing reaction medium 36 and separated waste gas. Deaerated suspension leaves the deaerating tank 600 through the channel 604. Deaerating tank 600 includes essentially upright, preferably cylindrical side wall 606 defining a deaeration zone 608. The deaeration zone 608 has a height "h" and the diameter "d". It is preferable that the hole 602 would have a diameter identical to the diameter "d" of the deaeration zone 608 or exceeding it. The height "h", the diameter d, the surface area and volume of the deaeration zone 608 preferably are essentially the same as that described above in regard to the deaeration zone 312 deaeration vessel 300, illustrated in figures 16-18.

If we refer now to figure 22, we can say that it is illustrated in bubble column reactor 20 figure 21, including alternative bubbler oxidant 620. Bubbler oxidant 620 includes a ring element 622 is a couple of channels of inlet holes 624, 626. The annular element 622 preferably has essentially the same configuration as the annular element 202 described above in regard to figures 12-15. The channel inlet ports 624, 626 pass upward through holes in the lower plate 48 of the shell of the tank 22 and provide a flow of oxidant in the annular element 622.

If we refer now to figure 23, we can say that it is illustrated in bubble column reactor 20 figure 21, which includes not using bubbler means of introducing the oxidant stream into the reaction zone 28. Configuration 23 the flow of oxidant into the reactor 20 provide through the channels for oxidant 630, 632. Channels for oxidant 630, 632 is connected with the corresponding holes for oxidant 634, 636 in the bottom plate 48 of the shell of the tank 22. The flow of oxidant injected directly into the reaction zone 28 through a hole oxidant 634, 636. To discard the current flow of oxidant immediately after its initial introduction into the reaction zone 28 can be provided for an optional chisels, 638, 640.

As mentioned above, it is preferable that the oxidation reactor would have a configuration and would function in accordance with the method, which allows to avoid areas of high concentrations of oxidizable compounds in the reaction medium, since such zones may Pref is particular to the formation of impurities. One way to improve the initial dispersion oxidizable compound (e.g., para-xylene) in the reaction medium is diluted oxidizable compounds liquid. The liquid used to dilute the oxidizable compounds, their source may be part of the reaction medium located at a considerable distance from the position (s)in which the reaction zone serves oxidizable compound. For a given fluid from a remote part of the reaction medium in the circulation can be fed to a position in the vicinity of the position of introduction of the oxidizable compounds through the channel for the flow, which is located inside and/or outside the main reaction vessel.

Figures 24 and 25 illustrate two preferred way of organizing the circulation of fluid from the distal part of the reaction medium feed position located close to the inlet for oxidizable compounds, when using the internal (figure 24) or external (figure 25) channel. Preferably the length of the channel to flow from its inlet holes (i.e. holes (holes), where the fluid enters the channel) to its outlet (i.e. holes (holes)where the liquid is released from the channel) is greater than about 1 meter, more preferably greater than around is about 3 meters, even more preferably in excess of about 6 meters, and most preferably greater than 9 meters. However, the actual length of the channel becomes less significant parameter, if the liquid is obtained from a separate container may be located immediately above or near capacity, which originally produced the original the feed material, formed by oxidative coupling. Fluid from any separate container containing at least some amount of the reaction medium, is the preferred source for the initial dilution of oxidizable compounds.

It is preferable that the liquid, return the fulfilled through the channel, regardless of the source would have a low stationary concentration of oxidizable compounds in comparison with the reaction medium adjacent at least one exhaust port. In addition, it is preferable that the liquid, return the fulfilled through the channel, would be the concentration of oxidizable compound in a liquid phase, less approximately 100000 hours/mn (wt.), more preferably less approximately 10,000 hours/mn (wt.), even more preferably, less approximately 1000 hours/mn (wt.), and most preferably less than 100 hours/mn (wt.), where the concentration is measured before adding to the channel portions on Asheboro oxidizable compound source material supplied and any optional separate source of supply of material, formed by the solvent. When carrying out measurement after adding portions formed oxidizable compound source material supplied and optional source feed material formed by the solvent, is preferred so that the combined stream of liquid flowing in the reaction medium, would be the concentration of oxidizable compound in a liquid phase, less approximately 300,000 hours/mn (wt.), more preferably less approximately 50,000 hours/mn (wt.), and most preferably less 10000 h/mn (wt.).

It is desirable to withstand the current through the channel at a level sufficiently low so that the circulating fluid is indeed suppressed desirable total gradient oxidizable compounds within the reaction medium. In this respect, it is preferable that the ratio between the mass of the liquid phase in the reaction zone, which originally release a portion of the oxidizable compound, and the mass flow rate, return the fulfilled through the channel, would exceed approximately 0.3 minutes, more preferably exceed about 1 minute, more preferably would be in the range from about 2 minutes to about 120 minutes, and most preferably from 3 minutes to 60 minutes.

There are many ways that stimulate the flow of liquids and through the channel. Preferred methods include the use of gravity, Doctorow of all types, using either gas or liquid or gas and the liquid as the motive fluid, and mechanical pumps of all types. In the case of the use of eductor in one embodiment of the invention as a driving fluid using at least one fluid medium selected from the group consisting of: the original feed material, formed by oxidative connection (liquid or gas), the original feed material, formed by the oxidizing agent (gas), the original feed material, formed by the solvent (liquid) and is supplied by a pump source to the reaction medium (suspension). In yet another variant implementation as a driving fluid using at least two fluids selected from the group consisting of: the original feed material, formed oxidizable compound, the original feed material, formed by the oxidant, and the original feed material, formed by the solvent. In yet another variant implementation as a driving fluid use a combination of the original feed material, formed oxidizable compound, the original feed material, formed by the oxidant, and the original feed material formed by the process is ielem.

Suitable diameter or diameters of the circulation channel can vary according to the quantity and properties of the transported material, the energy available to stimulate the flow, and considerations relating to capital expenditures. It is preferable that the minimum diameter of such a channel would exceed approximately 0,02 m, more preferably would be in the range of from about 0.06 to meter to about 2 meters, and most preferably from 0.12 to 0.8 meters.

As noted above, the current through the channel, it is desirable to regulate, soaking in certain preferred ranges. There are many known at the present level of ways of influencing the management of the job to the appropriate fixed geometry during fabrication of the channel for the flow. Another preferred embodiment is to use geometries, which may vary during operation, namely including the valves of all kinds and descriptions, including manual and mechanical control when using any means, including control loops with feedback from the receiving element or without it. Another preferred method of control for the diluted liquid is wererevealed energy between the inlet and the outlet of the channel. Preferred methods include the change in the flow rate for one or more driving fluid supplied to eductor, the change of the energy supply to the pump drive and the change of the difference in the densities or the difference of levels by height when using gravity. Data are the preferred methods also can be used in all combinations.

The channel used for the circulation of liquid from the reaction medium, can refer to any type known state of the art. In one embodiment, the implementation will use the channel, constructed entirely or partially using conventional materials for the manufacture of tubing. In yet another variant implementations use the channel, constructed entirely or partially using the walls of the reaction vessel as a part of the channel. The channel can be constructed fully included in the reaction vessel (figure 24), or it can be constructed located completely outside of the reaction vessel (figure 25), or it may include sections located both inside and outside the reaction vessel.

The inventors envisage that, especially in larger reactors, it may be desirable multiple channels and different options for moving fluid through the channel. In addition, it may be W the undesirable multiple outlets in multiple positions on a single channel or on all channels. Details of the construction will ensure the balance between the desirable total gradient of the stationary concentrations of oxidizable compounds and the desired initial dilution formed oxidizable compound source material supplied in accordance with other aspects of the present invention.

Figures 24 and 25 illustrate designs that use the deaerating tank, connected to the channel. This deaeration capacity ensures that part of the reaction medium used to dilute the incoming oxidizable compounds, represents essentially the deaerated suspension. However, at this point it should be noted that the liquid or slurry that is used to dilute the incoming oxidizable compounds can be in aerated form, and in deaerated form.

The use of fluid flowing through the channel, to provide dilution formed by oxidative coupling of the source feed material is particularly suitable for use in a bubbling reactor columns. In addition, bubbling reactor columns receive the greatest benefits from the initial dilution formed by oxidative coupling of the source of the feed material can be achieved even without dopamineproducing oxidizable compound source feed material directly into the channel provided that the outlet channel will be located close enough to the position of adding oxidizable compounds. In this implementation is preferred that the outlet channel was located to within about 27 diameters of the outlet channel from the closest position adding oxidizable compounds, more preferably within about 9 diameters of the outlet channel, even more preferably within about 3 diameters of the outlet channel, and most preferably within 1 diameter of the outlet channel.

It was also found that, even without the use of channels for receiving fluid dilution from a remote part of the reaction medium suitable for use in the initial dilution of the formed oxidized compound source material supplied in bubble columns oxidation, corresponding to one implementation variant of the present invention, can be eductor flow. In such cases, eductor have inside the reaction medium and he has a free pass from the reaction medium up to the neckline of eductor where low pressure will tighten adjoining reaction medium. Examples of two possible configurations of Doctorow illustrated in figures 26 and 27. In preference the equipment implementation of data Doctorow nearest the infeed position oxidizable compound is in the range of about 4 meters, more preferably within about 1 meter, and most preferably 0.3 meters from the mouth of eductor. In another embodiment, the implementation as a driving fluid under pressure serves oxidizable compound. In yet another variant implementation as an additional driving fluid together with the oxidizable compound is fed under pressure or solvent, or the oxidizer. And in yet another variant implementation as an additional driving fluid together with the oxidizable compound under pressure serves as a solvent and an oxidizing agent.

The inventors envisage that, especially in larger reactors, it may be desirable multiplicity of Doctorow various structures located in various positions within the reaction medium. Details of the construction will ensure the balance between the desirable total gradient of the stationary concentrations of oxidizable compounds and the desired initial dilution formed oxidizable compound source material supplied in accordance with other aspects of the present invention. In addition, the inventors envisage that the jet discharge from the outlet of eductor can be oriented in any direction. In the case of using the nogusta of Doctorow each eductor can be oriented individually, again in any direction.

As mentioned above, certain physical and operational characteristics of bubble column reactor 20, described above in regard to figures 1-27, ensure the presence of vertical gradients of pressure, temperature and concentration of the reagent (i.e. oxygen and oxidizable compounds) in reaction medium 36. As discussed above, the vertical gradients can provide more efficient and economical implementation of the method of oxidation in comparison with commonly used methods of oxidation that are favorable to obtaining a well-mixed reaction medium, characterized by a relatively uniform pressure, temperature and concentration of the reagent in all its parts. Further detail will be discussed vertical gradients for oxygen, oxidizable compound (e.g., para-xylene) and temperature, which make possible the use of the oxidation system in accordance with a variant implementation of the present invention.

If we turn now to the figure 28, we can say that in order to obtain quantitative characteristics of the gradients of the concentrations of the reactants present in the reaction medium 36 during oxidation in a bubbling reactor column 20, the total volume of reaction medium 36 can theoretically divide the ü 30 discrete horizontal lobes with equal volume. Figure 28 illustrates the concept of separation of reaction medium 36 30 discrete horizontal lobes with equal volume. Except for the top and the bottom horizontal lobes, each of the horizontal portion has a discrete volume limited by the upper and lower sides of the imaginary horizontal plane and bounded on its sides by the wall of the reactor 20. The upper horizontal portion is limited on the lower side of an imaginary horizontal plane, and on its upper side by the upper surface of the reaction medium 36. The lower horizontal portion is limited in its upper side an imaginary horizontal plane, and on its bottom side the bottom shell of the vessel. As soon as the reaction medium 36 is theoretically divided into 30 discrete horizontal lobes with equal volume, then it will be possible to determine srednekraevoy and volumetric average concentration for each horizontal lobe. Individual horizontal portion having the maximum concentration among all 30 horizontal lobes, can be identified as the horizontal portion of the C-max. Individual horizontal portion above the horizontal fraction of the C-max and have a minimum concentration among all horizontal lobes, located horizontally above the share of the C-max, can be identified as the horizontal portion of the C-min". After that, the vertical concentration gradient can be calculated as the ratio between the concentration in the horizontal lobe of the C-max and the concentration in the horizontal beat-minutes

As for obtaining quantitative characteristics of the gradient of oxygen concentration, when the reaction medium 36 is theoretically divided into 30 discrete horizontal lobes with equal volume, the horizontal portion About2-max identified as having the maximum oxygen concentration to 30 horizontal lobes, while the horizontal portion About2-min identify as having a minimum concentration of oxygen in the number of horizontal lobes located above the horizontal share About2-Max. oxygen Concentration in the horizontal fractions measured in the gas phase of reaction medium 36 in the form of srednerazmernyh and volumetric average molar quantities in the calculation for the wet state. It is preferable that the ratio between the concentration of oxygen in the horizontal fraction Of2-max and the concentration of oxygen in the horizontal fraction Of2min would be in the range from about 2:1 to about 25:1, more preferably in the range of from about 3:1 to about 15:1, and most preferably in the range of the t 4:1 to 10:1.

Usually, the horizontal portion About2-max will be located near the bottom of reaction medium 36, while the horizontal portion About2-min will be located near the top of reaction medium 36. Preferably, the horizontal portion About2-min will be one of the top 5 most horizontal share among the 30 discrete horizontal portion. Most preferably, the horizontal portion About2min represents the highest share among the 30 discrete horizontal lobes, as illustrated in figure 28. Preferably, the horizontal portion About2max is one of the 10 most lower horizontal share among the 30 discrete horizontal portion. Most preferably, the horizontal portion About2max is one of the 5 most lower horizontal share among the 30 discrete horizontal portion. For example, figure 28 illustrates the horizontal portion About2-max as a third horizontal portion from the bottom of reactor 20. Is preferred that the spacing vertically between the horizontal portions Of2-min and2max would be at least approximately 2W, more preferably at least about 4W, and most preferably at least 6W. Is preferred that the spacing in the vertical is between the horizontal portions Of 2-min and2max would be at least about 0.2 n, more preferably at least about 0,4H, and most preferably at least 0,6N.

Sredneuralskaya and volumetric average concentration of oxygen in the horizontal fraction Of2-min when calculating the wet state is preferably in the range from about 0.1 to about 3 mole percent, more preferably in the range of from about 0.3 to about 2 mole percent, and most preferably in the range from 0.5 to 1.5 mole percent. Sredneuralskaya and volumetric average concentration of oxygen in the horizontal fraction Of2max is preferably in the range from about 4 to about 20 mole percent, more preferably in the range of from about 5 to about 15 mole percent, and most preferably in the range from 6 to 12 mole percent. Sredneuralskaya oxygen concentration in the gaseous exhaust stream discharged from the reactor 20 through the outlet for gas 40, when calculating the dry state is preferably in the range from about 0.5 to about 9 mole percent, more preferably in the range of from about 1 to about 7 mole percent, and most ol doctitle in the range from 1.5 to 5 molar percent.

Since the concentration of oxygen is very noticeably decreases towards the top of reaction medium 36, it is desirable that the oxygen demand in the area of the top of reaction medium 36 would be reduced. For this reduced oxygen demand near the top of reaction medium 36 can be achieved in the establishment of a vertical gradient of concentration of the oxidizable compound (e.g., para-xylene), when the minimum concentration of oxidizable compounds will be near the top of reaction medium 36.

As for obtaining quantitative characteristics of the gradient of the concentration of oxidizable compound (e.g., para-xylene), then, when the reaction medium 36 is theoretically divided into 30 discrete horizontal lobes with equal volume, the horizontal portion of the OS-max will be identified as having the maximum concentration of oxidizable compounds among all 30 horizontal lobes, while the horizontal portion of the OS-min will be identified as having a minimum concentration of oxidizable compounds in the number of horizontal lobes located above the horizontal lobe OS-Max. concentration of oxidizable compound in a horizontal fractions measured in the liquid phase in calculating the value sredneuralskoj and volumetric average mass share. It is preferable that the ratio between the concentration of oxidizable compound in a horizontal lobe OS-max and the concentration of oxidizable compound in a horizontal lobe OS-min would have been more than about 5:1, more preferably exceed about 10:1, even more preferably exceed about 20:1, and most preferably would be in the range from 40:1 to 1000:1.

Usually the horizontal portion of the OS-max will be located near the bottom of reaction medium 36, while the horizontal portion of the OS-min will be located near the top of reaction medium 36. Preferably, the horizontal portion of the OS-min is one of the top 5 most horizontal share among the 30 discrete horizontal portion. Most preferably, the horizontal portion of the OS-min represents the highest share among the 30 discrete horizontal lobes, as illustrated in figure 28. Preferably, the horizontal portion of the OS-max is one of the 10 most lower horizontal share among the 30 discrete horizontal portion. Most preferably, the horizontal portion of the OS-max is one of the 5 most lower horizontal share among the 30 discrete horizontal portion. For example, figure 28 illustrates the horizontal portion of the OS-max as the fifth horizontal portion from the bottom of reactor 20. Is preferred that the spacing vertically between the horizontal portions of the OS-min and OC-max would be at least approximately 2W, where "W" is a Maxim is inuu width of reaction medium 36. More preferably the spacing vertically between the horizontal portions of the OS-min and OC-max is at least approximately 4W, and most preferably at least 6W. If the reaction medium 36 height "H" is preferred that the spacing vertically between the horizontal portions of the OS-min and OC-max would be at least about 0.2 n, more preferably at least about 0,4H, and most preferably at least 0,6N.

Sredneuralskaya and volumetric average concentration of oxidizable compound (e.g., para-xylene) in the liquid phase in the horizontal lobe OS-min is preferably less than approximately 5000 h/mn (wt.), more preferably less than approximately 2000 hours/mn (wt.), even more preferably less than approximately 400 hours/mn (wt.), and most preferably in the range from 1 h/mn (wt.) up to 100 hours/mn (wt.). Sredneuralskaya and volumetric average concentration of oxidizable compound in a liquid phase in the horizontal lobe OS-max is preferably in the range from approximately 100 h/mn (wt.) up to approximately 10,000 hours/mn (wt.), more preferably in the range of from about 200 h/mn (wt.) to about 5000 h/mn (wt.), and most preferably in the range from 500 h/mn (wt.) to C./mn (wt.).

Despite the fact that preferred to bubble column reactor 20 would be available for the concentration of oxidizable compounds gradients vertically, is preferred also that the volume percent of the reaction medium 36, having a concentration of oxidizable compound in a liquid phase in excess of 1000 hours/mn (wt.), would be minimized. Preferably sredneuralskoj volume percent of the reaction medium 36, having a concentration of oxidizable compound in a liquid phase in excess of 1000 hours/mn (wt.), is less than about 9%, more preferably less than about 6 percent, and most preferably less than 3 percent. Preferably sredneuralskoj volume percent of the reaction medium 36, having a concentration of oxidizable compound in a liquid phase in excess of 2500 hours/mn (wt.), is less than about 1.5%, more preferably less than about 1 percent, and most preferably less than 0.5 percent. Preferably sredneuralskoj volume percent of the reaction medium 36, having a concentration of oxidizable compound in a liquid phase in excess of 10000 hours/mn (wt.), is less than about 0.3%, more preferably less than about 0.1 percent, and is, most preferably less than 0.03 percent. Preferably sredneuralskoj volume percent of the reaction medium 36, having a concentration of oxidizable compound in a liquid phase in excess of 25000 hours/mn (wt.), is less than about 0.03%, more preferably less than approximately 0,015%, and most preferably less than 0.007 percent. The inventors have noted that the volume of reaction medium 36, characterized by elevated levels of oxidizable compounds, not necessarily coincide with one volume formed adjacent to each of its parts. At different points in time chaotic circuit currents in the reaction vessel in bubble columns lead to the formation of two or more solid, but the segregated parts of reaction medium 36, characterized by elevated levels of oxidizable compounds. In every moment of time that is used when averaged over time, all such solid, but segregated amounts in excess of 0.0001 volume percent of the total reaction medium, piled with each other to determine the total volume, which is characterized by elevated concentrations of oxidizable compounds in the liquid phase.

In addition to the gradients of the concentrations of oxygen and oxidizable compounds discussed in the above, is preferred that the reaction medium 36, there would be a temperature gradient. If we refer again to figure 28, we can say that the quantitative characteristics of this temperature gradient can be obtained by the method similar to obtaining quantitative characteristics of the gradients of concentrations, theoretical separation of reaction medium 36 30 discrete horizontal lobes of equal size and dimension sredneuralskoj and volumetric average temperature in each lobe. Then the horizontal portion, characterized by the lowest temperature among the bottom 15 of the horizontal lobes, can be identified as the horizontal portion of the T-min and a horizontal portion above the horizontal fraction of the T-min and a maximum temperature among all of the shares above the horizontal fraction of the T-min, after that you can identify as the horizontal portion of the T-max. It is preferable that the temperature of the horizontal fraction of T-max would be at least about 1°C higher than the temperature of the horizontal fraction of T-min is More preferable temperature horizontal lobe of the T-max is in the range of temperatures higher than the temperature of the horizontal fraction of the T-min value in the range from about 1.25 to about 12°C. Most preferably the rate is temperature horizontal lobe of the T-max is in the range of temperatures, higher than the temperature of the horizontal fraction of the T-min value in the range from 2 to 8°C. the temperature of the horizontal fraction of the T-max is preferably in the range from about 125 to about 200°C., more preferably in the range of from about 140 to about 180°C., and most preferably in the range of from 150 to 170°C.

Usually the horizontal portion of the T-max will be located close to the center of reaction medium 36, while the horizontal portion of the T-min will be located near the bottom of reaction medium 36. Preferably, the horizontal portion of the T-min is one of the 10 most lower horizontal share among the 15 most of the lower horizontal portion. Most preferably, the horizontal portion of the T-min is one of the 5 most lower horizontal share among the 15 most of the lower horizontal portion. For example, figure 28 illustrates the horizontal portion of the T-min as the second horizontal portion from the bottom of reactor 20. Preferably, the horizontal portion of the T-max is one of 20 middle horizontal share among the 30 discrete horizontal portion. Most preferably, the horizontal portion of the T-min is one of the 14 secondary horizontal share among the 30 discrete horizontal portion. For example, figure 28 illustrates the horizontal the stake T-max as the twentieth horizontal portion from the bottom of reactor 20 (that is one of the medium 10 horizontal equity). Is preferred that the spacing vertically between the horizontal portions of the T-min and T-max would be at least approximately 2W, more preferably at least about 4W, and most preferably at least 6W. Is preferred that the spacing vertically between the horizontal portions of the T-min and T-max would be at least about 0.2 n, more preferably at least about 0,4H, and most preferably at least 0,6N.

As discussed above, in the case of existence in reaction medium 36 temperature gradient vertically may be the best selection of reaction medium 36 in a position elevated location where the temperature of the reaction medium is maximum, especially when the later stages of the technological scheme of the selected product will be subjected to further processing at elevated temperatures. Thus, if the reaction medium 36 is withdrawn from the reaction zone 28 via one or more outlets elevated location, as illustrated in figures 19 and 20, it is preferred that the exhaust opening (s) elevated location would lie close to the horizontal in the share of T-Max. Preferably the outlet value is about level location is located within 10 horizontal stake from the horizontal fraction of T-max, more preferably within 5 horizontal stake from the horizontal fraction of T-max, and most preferably within 2 horizontal stake from the horizontal fraction of the T-max

At the moment, it should be noted that many of the features of the invention described herein can be used in systems with multiple oxidation reactors, not just in systems that use only the oxidation reactor. In addition, certain features of the invention described herein can be used in the oxidation reactors with mechanical stirring and/or mixing of the flow, and not just in reactors with bubbling stirring (i.e. bubbling reactor columns). For example, the inventors have identified certain advantages associated with the break on level/variation of concentration of oxygen and/or the rate of consumption of oxygen in the whole volume of the reaction medium. The advantages realized in the split in the degree of concentration/consumption of oxygen in the reaction medium, can be implemented regardless of whether the total volume of the reaction medium contained in a single container or in multiple containers. Furthermore, the benefits realized in the breaking in stage against the AI concentration/consumption of oxygen in the reaction medium, you can implement regardless of whether the reaction capacity (capacity) to have mechanical stirring, mixing, flow and/or bubbling stirring.

One way of obtaining quantitative characteristics for granularity on the level of concentration and/or the rate of consumption of oxygen in the reaction environment is to compare two or more distinct 20-percent continuous volume of the reaction medium. Data 20-percent continuous volumes do not necessarily have to be defined to any specific form. However, each 20-percent continuous volume must be generated from the volume of the reaction medium formed adjacent to each of its parts (that is, each volume is "solid"), and a 20-percent continuous volumes must not overlap with each other (i.e., the volumes are "detached"). Figures 29-31 illustrate that these separate 20-percent continuous volumes can reside in the same reactor (figure 29) or in several reactors (figures 30 and 31). It should be noted that the reactors illustrated in figures 29-31, can be a reactor with mechanical stirring, mixing, flow and/or bubble mixing. In one embodiment, the implementation is preferred that the reactor, Provillus is new in figures 29-31, would represent a reactor with bubble mixing (i.e. bubble column reactor).

If we refer now to figure 29, we can say that there is illustrated a reactor 20 containing reaction medium 36. The reaction medium 36 includes a first distinct 20-percent continuous volume 37 and the second distinct 20-percent continuous volume of 39.

If we turn now to the figure 30, we can say that there is illustrated a system with multiple reactors, including the first reactor a and second reactor 720b. Reactors a, b together contain the total volume of the reaction medium 736. The first reactor a accommodates the first part of the reaction medium a, while the second reactor 720b accommodates the second part of the reaction medium 736b. The first distinct 20-percent continuous volume 737 reaction medium 736 demonstrated as defined within the first reactor a, while the second distinct 20-percent continuous volume 739 reaction medium 736 demonstrated as defined within the second reactor 720b.

If we refer now to figure 31, we can say that there is illustrated a system with multiple reactors, including the first reactor a, the second reactor 820b and the third reactor s. Reactors a, b, c together contain the total volume of the reaction medium 836. First implement the tor a accommodates the first part of the reaction medium a; the second reactor 820b accommodates the second part of the reaction medium 836b; and a third reactor s holds the third part of the reaction medium s. The first distinct 20-percent continuous volume 837 reaction medium 836 demonstrated as defined within the first reactor a; second distinct 20-percent continuous volume 839 of the reaction medium 836 demonstrated as defined within the second reactor 820b; and a third distinct 20-percent continuous volume 841 of the reaction medium 836 demonstrated as defined within the third reactor s.

The split ratio in relation to the availability of oxygen in the reaction environment can be quantitatively described with reference to a 20-percent continuous volume of the reaction medium containing the most enriched molar fraction of oxygen in the gas phase, and when referring to a 20-percent continuous volume of the reaction medium containing the most depleted molar fraction of oxygen in the gas phase. In the gas phase separate 20-percent continuous volume of the reaction medium with higher concentration of oxygen in the gas phase, Sredneuralskaya and volumetric average concentration of oxygen in the calculation for the wet state, preferably is in the range from about 3 to about 18 mole percent, more preferably in the range is from about 3.5 to about 14 mole percent, and most preferably in the range of from 4 to 10 molar percent. In the gas phase separate 20-percent continuous volume of the reaction medium with the lowest concentration of oxygen in the gas phase, Sredneuralskaya and volumetric average concentration of oxygen in the calculation for the wet state, preferably is in the range from about 0.3 to about 5 mole percent, more preferably in the range of from about 0.6 to about 4 mole percent, and most preferably in the range of from 0.9 to 3 mole percent. In addition, the ratio between srednerazmernymi and volumetric average concentration of oxygen in the calculation for the wet state, in the most enriched 20-percent continuous volume of the reaction medium and in the most depleted in 20-percent continuous volume of the reaction medium is preferably in the range from about 1.5:1 to about 20:1, more preferably in the range of from about 2:1 to about 12:1, and most preferably in the range of from 3:1 to 9:1.

Quantitative characteristics for splitting ratio in relation to the rate of consumption of oxygen in the reaction medium can be obtained by expression through the STR value for oxygen, which originally was described above. The STR value for oxygen was earlier description is but in a global sense (i.e. from the perspective of the average value STR oxygen to the total reaction medium); however, the STR value for oxygen can also be understood in a local sense (i.e. part of the reaction medium in order to obtain quantitative characteristics for splitting ratio in relation to the rate of consumption of oxygen in the whole volume of the reaction medium.

The inventors have found that is very useful stimulus variation value STR oxygen throughout the volume of the reaction medium in accordance with the desired gradients described in this document in relation to the pressure in the reaction medium and the molar fraction of molecular oxygen in the gas phase reaction medium. Thus, it is preferred that the ratio between the amount of STR on oxygen for the first separate 20-percent continuous volume of the reaction medium and the STR value for oxygen for the second separate 20-percent continuous volume of the reaction medium would be in the range from about 1.5:1 to about 20:1, more preferably in the range of from about 2:1 to about 12:1, and most preferably in the range of from 3:1 to 9:1. In one embodiment, the implementation in comparison with the "second separate 20-percent continuous volume" "first distinct 20-percent continuous volume" is closer to the position where the reaction medium original is introducing molecular oxygen. Data large gradients of STR values for oxygen are desirable regardless of whether the reaction medium partial oxidation to fit in a bubble reactor column oxidation or any other type reaction vessel in which the pressure gradients and/or mole fraction of molecular oxygen in the gas phase of the reaction medium (for example, in the vessel with mechanical stirring, with multiple vertical zones of mixing that is achieved by using multiple impellers, characterized by the presence of strong radial flow, with the possible strengthening of the result in the availability of prefabricated modules as in the General case of the horizontal partitions, the oxidant stream rises in the General case upwards from the inlet near the bottom of the reaction vessel, despite the fact that within each located vertically mixing zone may be a significant level of back-mixing of the oxidant stream, and that a certain level of back-mixing of the oxidant stream may occur between adjacent spaced vertical mixing areas). That is, the inventors found that if the pressure gradient and/or mole fraction of molecular oxygen in the gas is howling phase reaction medium is desirable to create such a gradient in the chemical needs of dissolved oxygen in the ways described in this document.

Preferred ways to stimulate the local variation of STR values for oxygen are in management positions feed oxidizable compounds and in the management of agitation of the liquid phase reaction medium in order to regulate the gradients of the concentration of oxidizable compound in accordance with other aspects of the description of the present invention. Other suitable ways to stimulate the local variation of STR values include the promotion of variation of activity in response to the stimulation of the variation of the local temperature and the local changes of the mixture components of the catalyst and solvent (for example, the introduction of additional quantities of gas to promote cooling by evaporation in a specific part of the reaction medium and by adding a stream of solvent containing an increased amount of water to reduce activity in a specific part of the reaction medium).

As discussed above in regard to figures 30 and 31, the partial oxidation reaction in a suitable case can be performed in multiple reaction vessels, where at least part, preferably at least 25%, more preferably at least 50 percent, and most preferably, at the ore, 75 percent, from molecular oxygen, leaving the first reaction chamber, perepuskat in one or more subsequent reaction vessels for spending additional portion, preferably more than 10%, more preferably more than 20%, and most preferably more than 40 percent, from molecular oxygen, leaving the button before the flowsheet of the reaction vessel. When using such a sequential flow of molecular oxygen from one reactor to the other, it is desirable that the first reaction chamber would function at the intensity of the reaction was higher in comparison with what occurs in at least one subsequent reaction vessels, preferably with a ratio between the average capacity value STR oxygen within the first reaction vessel and the average capacity value STR oxygen within the subsequent reaction vessel in the range from about 1.5:1 to about 20:1, more preferably in the range of from about 2:1 to about 12:1, and most preferably in the range of from 3:1 to 9:1.

As discussed above, suitable for serial flow of molecular oxygen in the following reaction vessel in accordance with this is Subramaniam are all types of the first reaction vessel (for example, bubble column apparatus with mechanical stirring, with a back-mixing, with an internal division into stages, over in the ideal mode of displacement, and the like) and all the subsequent types of reaction vessels that can be treated or may not be related to the type different from the first reaction vessel. Ways to stimulate the reduction in average capacity value STR oxygen within the subsequent reaction vessels in an appropriate case, include decreasing temperature, decreasing concentrations of oxidizable compounds and the reduction in activity in response to specific mixture of catalyst components and solvent (e.g., reduced cobalt concentration, increasing the concentration of water and add a moderator of a catalyst, such as a small amount of ionic copper).

When the flow from the first reaction vessel in a subsequent reaction chamber, the oxidant stream may be processed using any of the methods known at the present level of technology, such as compression or reduction of pressure in the cooling or heating and the removal of mass or added mass in any number or any type. However, the use of the reduction in average capacity value STR oxygen in the following reaction vessels is in osobennosyatm then when the absolute pressure in the upper part of the first reaction vessel is less than about 2.0 MPa, more preferably less than approximately 1.6 R, and most preferably less than 1.2 R. In addition, the use of the reduction in average capacity value STR oxygen in the following reaction vessels is particularly useful when the ratio between the absolute pressure in the upper part of the first reaction vessel and the absolute pressure in the upper part, at least one subsequent reaction vessel is in the range from about 0.5:1 to 6:1, more preferably in the range from approximately 0.6:1 to about 4:1, and most preferably in the range of from 0.7:1 to 2:1. Reducing the pressure in the subsequent tanks to a level smaller data lower limits, is superimposed on the decreasing availability of molecular oxygen, and the increase in pressure above data upper limits requires significant costs in comparison with the use of fresh feed oxidant.

When using a serial flow of molecular oxygen in the following reaction vessel, characterized by a reduction in the average capacity values STR oxygen, fresh air flows source supplied is of the material, formed oxidizable compound, solvent and oxidant can flow into the subsequent reaction vessel and/or in the first reaction chamber. The flow of the liquid phase and the solid phase, if any, of the reaction medium can be moved in any direction between reaction vessels. The entire quantity or part of the gas phase leaving the first reaction chamber and received in a subsequent reaction vessel may flow separated from the parts of the liquid phase or the solid phase, if any, of the reaction medium from the first reaction vessel or may flow mixed with them. The flow of the product containing liquid phase and a solid phase, if any, may be directed to the selection of the reaction medium in any reaction vessel in the system.

If we refer again to figures 1-29, we can say that the oxidation is preferably carried out in a bubbling reactor column 20 in conditions which are in accordance with a preferred variant implementation, described herein, are significantly different from what occurs in the case of commonly used oxidation reactors. In the case of bubble column reactor 20 for carrying out liquid-phase partial oxidation of para-xylene to obtain crude crude terephthalic acid (CTA) in accordance with the tvii preferred variant implementation, described in this document, in the formation of particles of a HUNDRED, with a unique and advantageous properties, contribute to the spatial profiles of the local intensity of the reaction, the local evaporation rates and local temperature in combination with the schemes of fluid flow in the reaction medium and the preferred relatively low temperature oxidation.

Figures 32A and 32V illustrate the basic particles of a HUNDRED, obtained in accordance with one implementation of the present invention. Figure 32A shows the basic particles of a HUNDRED with a 500-fold increase, while figure 32V on an enlarged scale represents one of the basic particles HUNDRED and demonstrates the particle at 2000-fold increase. As can best be illustrated in figure 32V, each base particle HUNDRED usually formed from a large number of small agglomerate of subparticles of a HUNDRED, which, therefore, results in a base particle HUNDRED, with a relatively large specific surface area, high porosity, low density and good solubility. The base particles HUNDRED usually are characterized by an average particle size in the range from about 20 to about 150 microns, more preferably in the range of from about 30 to about 120 m of the crowns, and most preferably in the range of from 40 to 90 microns. Subunit HUNDRED usually are characterized by an average particle size in the range from about 0.5 to about 30 microns, more preferably from about 1 to about 15 microns, and most preferably in the range from 2 to 5 microns. A relatively large specific surface area of the base particles of a HUNDRED, is illustrated in figures 32A and 32V, can be quantitatively described using the method of measuring the specific surface area of Brunauer-Emmett-teller (BET). Preferably, the base particles are characterized by a HUNDRED average specific surface area according to BET method, is equal to at least approximately 0.6 square meters per gram (m2/g). More preferably, the base particles are characterized by a HUNDRED average specific surface area according to BET method in the range from approximately 0.8 to approximately 4 m2/, Most preferably, the base particles are characterized by a HUNDRED average specific surface area according to BET method in the range from 0.9 to 2 m2/, Physical properties (e.g. particle size, specific surface area according to BET method, porosity and solubility) of the base particles HUNDRED received in accordance with the optimized method ocil is of preferred embodiments of the present invention, make possible the cleaning particles HUNDRED by using more efficient and/or economical ways, described in more detail hereinafter in connection with figure 35.

Values of average particle sizes presented above was determined using microscopy in polarized light and methods of image analysis. The equipment used in the analysis of particle sizes, included optical microscope Nikon E800 lens 4×Plan Flour N. A. 0.13, digital camera Spot RT™ and a personal computer with installed software for image analysis Image Pro Plus™ V4.5.0.19. The method of analysis of particle sizes included the following main stages: (1) dispersing powder of a HUNDRED in mineral oil; (2) obtaining a preparation for microscopy as the variance between the objective and the cover glass microscope; (3) the emergence of the preparation for microscopy using microscopy in polarized light (the state of the crossed polarizers - particles are observed as bright objects on a black background); (4) fixation of different images for each case for the preparation of samples (the size of the image field = 3×2.25 mm; the size of the picture element = 1,84 microns/pixel image); (5) analysis of the images using the software Image Pro Plus™; (6) transfer of measurement results for particles in electroneutrality; and (7) the operation of the statistical processing characteristics in the spreadsheet. Stage (5) "analysis of the images using the software Image Pro Plus™" included a sub-phases: (a) setting a threshold value for the image in order to detect white particles on a dark background; (b) create a black and white image; (C) actuate the forward open filter for filtering noise of the image elements; (d) the measurement for all particles in the image; and (e) the issuance of data on the average diameter measured for each particle. The software Image Pro Plus™ determines the average diameter of individual particles in the form of srednekamennogo length of the diameters of the particles, measured at intervals of 2 degrees and passed through the operation of determining the center of gravity of the particles. Stage 7 the operation of the statistical processing characteristics in the spreadsheet includes the calculation of volume-weighted average particle size in the following way. The volume of each of the n particles in the sample is calculated as if it was spherical, as a result of using the formula π/6*di^3; multiplying the volume of each particle on its diameter with obtaining π/6*di^4; summation for all particles in the sample values π/6*di^4; summing the volumes of all particles in which brazze; and calculate the volume-weighted particle diameter as the sum of the values (π/6*di^4) for all n particles in the sample divided by the sum of (π/6*di^3) for all n particles in the sample. In accordance with the usage in this document, the "average particle size" means the volume-weighted average particle size, determined in accordance with the above-described test method; and it is also designated as D(4, 3).

In addition, the stage 7 includes the establishment of particle sizes for which various percentages of the total sample are characterized by smaller particles. For example, D(v, 0,1) represents the particle size for which 10 percent of the total sample are characterized by a smaller particle size, and 90 percent are large in particle size D(v, 0,5) represents the particle size for which half the volume of the sample is characterized by a large particle size, and the other half has a smaller particle size; D(v, 0,9) represents the particle size for which 90 percent of the total sample are characterized by a smaller particle size; and so on. In addition, the stage 7 includes calculating the value of D(v, 0,9) minus D(v, 0,1), which is herein defined as "the range of particle sizes; and stage 7 including the AET value calculation of the dispersion of particle sizes, divided by the value D(4, 3), which is herein defined as "the relative dispersion of particle sizes".

In addition, it is preferable that the value of D(v, 0,1) for particles of a HUNDRED, measured above, would be in the range from about 5 to about 65 microns, more preferably in the range of from about 15 to about 55 microns, and most preferably in the range of from 25 to 45 microns. It is preferable that the value of D(v, 0.5) is for particles HUNDRED, measured above, would be in the range from about 10 to about 90 microns, more preferably in the range of from about 20 to about 80 microns, and most preferably in the range of from 30 to 70 microns. It is preferable that the value of D(v, 0,9) for particles of a HUNDRED, measured above, would be in the range from about 30 to about 150 microns, more preferably in the range of from about 40 to about 130 microns, and most preferably in the range from 50 to 110 microns. Is preferred that the relative dispersion of particle sizes would be in the range from approximately 0.5 to approximately 2.0, more preferably in the range of from about 0.6 to about 1.5, and most preferably in the range from 0.7 to 1.3.

Values of specific surface area according to the met who do BET, above was measured using Micromeritics instrument ASAP2000 (available in the company Micromeritics Instrument Corporation of NORCROSS, GA). In the first stage of the method of measurement from 2 to 4 grams of sample particles were weighed and dried in vacuum at 50°C. then the sample was placed in a gas collector for analysis and cooled to 77 K. Isotherm adsorption of nitrogen was measured at least at 5 equilibrium pressures as a result of exposure to a sample of known volume of gaseous nitrogen and measuring the pressure drop. The equilibrium pressure in a suitable case was in the range of R/R0=0,01-0,20, where P represents the equilibrium pressure, and R0represents the vapor pressure of liquid nitrogen at 77 K. Then spent a graphic plot for the resulting isotherms in accordance with the following equation method BET:

,

where Varepresents the volume of gas adsorbed by the sample at R, Vmrepresents the volume of gas required to cover the total surface of the sample by a monolayer of gas, and is a constant. From this graph determine the values of Vmand C. then Vmwere counted in the specific surface area when using the cross-sectional area of nitrogen at 77 K according to the formula:

p> ,

where σ is the cross sectional area of nitrogen at 77 K, T is equal to 77 K, and R is the gas constant.

As mentioned above, a HUNDRED, obtained in accordance with one implementation of the present invention shows excellent characteristics of dissolution in comparison with the usual one HUNDRED obtained using other methods. This improved the dissolution rate makes possible the purification of one HUNDRED of the invention by using more efficient and/or more efficient methods of cleaning. The following description refers to the method by which it is possible to obtain quantitative characteristics for the dissolution rate of a HUNDRED.

The dissolution rate of a known quantity of solid phase in a known amount of solvent to stir the mixture can be measured in accordance with different protocols. In accordance with the use in the present invention, the method of measurement known as the "test dissolution time", is determined as follows. During all tests the dissolution time use the ambient pressure equal to approximately 0.1 to R. The ambient temperature used during the entire test on the dissolution time is approximately 22°C. in Addition, before whom rosedene tests for the solid phase, solvent and all the equipment for dissolution was achieved achieve full thermal equilibrium at a given temperature and for a period of time dissolve any appreciable heating or cooling chemical glass or its contents were noted. Formed by the solvent portion in the form of fresh tetrahydrofuran brand "pure for analysis by the method of ghvd" (with a purity of >99.9%), hereafter in this document referred to as THF, in the amount of 250 grams is placed in a cleaned glass chemical glass high form KIMAX volume of 400 ml (part number Kimble® 14020, the company Kimble/Kontes, Finland, new Jersey), which is metalloservisnymi having a smooth wall and generally cylindrical in shape. In chemical beaker placed magnetic stirrer with Teflon coating (VWR part number 58948-230, a length of approximately 1 inch and a diameter of 3/8 inch, with an octagonal cross-section, the company VWR International, West Chester, PA 19380), where it naturally falls to the bottom. The sample is stirred using a magnetic stirrer Variomag® multipoint 15 (H&P Labortechnik AG, Oberschleissheim, Germany) installing it on rotation at 800 revolutions per minute. This mixing begins not more than 5 minutes before adding the solid phase and stationary food is supplied for at least 30 minutes after adding the solid phase. In a non-stick cuvette for otoshiana samples weighed a solid sample in the form of particles of raw crude or purified TPA in the amount of 250 milligrams. At the initial time, denoted as t=0, all weighed a solid phase immediately pour in mixed THF and simultaneously start the stopwatch. With proper operation THF quickly wets the solid phase and forms a dilute well mixed suspension within 5 seconds. After that, the samples of the mix get in the subsequent moments of time, measured in minutes from t=0: 0,08, 0,25, 0,50, 0,75, 1,00, 1,50, 2,00, 2,50, 3,00, 4,00, 5,00, 6,00, 8,00, 10,00, 15,00 and 30,00. Every little diluted sample is withdrawn from the well-mixed mixture when using a new disposable syringe (Becton, Dickinson and Co, 5 ml, REF 30163, Franklin-the lakes, new Jersey 07417). Immediately after the selection of chemical glass in a new labeled glass vials for samples when using a new unused syringe filter (25 mm diameter, 0.45 micron Gelman GHP Acrodisc GF®, the company Pall Corporation, East hills, NY 11548) just released about 2 milliliters transparent liquid sample. The duration of each filling of the syringe, placing the filter in and released in vials for samples in a proper case the e is a value, less than about 5 seconds, and the interval in the appropriate case begins and ends within about 3 seconds in one direction or another from each target duration time of selection of the sample. Within approximately five minutes from each filling vials for samples covered with a lid and incubated at approximately a constant temperature until the subsequent chemical analysis. After selection of the final sample at the moment of time corresponding to the passage of 30 minutes after t=0, all sixteen samples analyzed to establish the amount of dissolved TRA when using ghud-DME, in the General case described elsewhere in this description. However, in this test as the calibration standards, and the results are calculated as milligrams of dissolved TRA per gram of solvent THF (here and hereinafter in this document, including per million) in THF"). For example, if all 250 milligrams of the solid phase would be a very clean TRA, and if this total amount would be fully dissolved in 250 grams of solvent THF before he was selected a particular sample, then correct the measured concentration would be approximately 1000 hours/million in THF.

If a HUNDRED, corresponding to the present invention, boutport described above to test the dissolution time then it is preferred that the sample taken after one minute after t=0, was dissolved up to a concentration equal to at least about 500 hours/million in THF, more preferably at least 600 hours/million in THF. In the case of a sample taken after two minutes after t=0, is preferred to a HUNDRED, corresponding to the present invention was dissolved up to a concentration equal to at least approximately 700 hours/million in THF, more preferably at least 750 hours/million in THF. In the case of a sample taken after four minutes after t=0, is preferred to a HUNDRED, corresponding to the present invention was dissolved up to a concentration equal to at least approximately 840 hours/million in THF, more preferably at least 880 hours/million in THF.

The inventors have found that when describing the time dependence for the complete data set of all tests for dissolution in appropriate time is a relatively simple model negative exponential growth regardless of the complexity of the particles and method of dissolution. Form of the equation, here and later in this document called "dissolution time"represents the following:

S=A+B*(1-exp(-C*t)), where

t - time unit minute;

S - solubility with a unit of measure hours/the LF in THF at time t;

exp - exponential function natural logarithm base 2;

A, b - constants regression with a unit of measure hours/million in THF, where a is primarily attributable to the rapid dissolution of smaller particles for very short periods of time, and where the sum a+b mainly refers to the total level of dissolved shortly before the completion of the specified test period; and

With the time constant regression with units of inverse time.

Constant regression adjust, seeking to minimize the sum of squared deviations of actual experimental data from the corresponding values in the model, this method is usually called the approximation by the method of "least squares". The preferred software package dedicated to the regression data is JMP Release 5.1.2 (SAS Institute Inc., JMP Software, SAS-Campus Drive, Cary, North Carolina 27513).

In the event, for a HUNDRED, corresponding to the present invention, a testing method for testing the dissolution time and approximation in accordance with the described above model the dissolution time is preferred to a HUNDRED could be characterized by a time constant "C"in excess of approximately 0.5 inverse minutes, more preferably greater than approximately 0.6 reverse is displaced, and most preferably greater than 0.7 and backward minutes.

Figures 33A and 33B illustrate a conventional particle HUNDRED, obtained using the conventional method of high-temperature oxidation in the hull reactor with continuous mixing (CSTR). Figure 33A illustrates a typical particle HUNDRED with a 500-fold increase, while figure 33B represents the image in an enlarged scale and shows the particle HUNDRED at 2000-fold increase. Visual mapping of HUNDRED particles of the invention illustrated in figures 32A and 32V, and the usual HUNDRED particles, illustrated in figures 33A and 33B, indicates that an average particle HUNDRED is characterized by increased density, smaller specific surface area, less porosity and a large particle size in comparison with a HUNDRED particles of the invention. In fact, the usual HUNDRED, shown in figures 33A and 33B, is characterized by an average particle size of approximately 205 microns and a specific surface area according to BET method, of approximately 0,57 m2/year

Figure 34 illustrates a commonly used method of obtaining a purified terephthalic acid (MOUTH). In the commonly used method of obtaining the mouth of the para-xylene is subjected to partial oxidation in high-temperature oxidation reactor with mechanical what remesiana 700. The suspension, containing one HUNDRED, from the reactor 700 selected, and then cleaned in the cleaning system 702. Product MOUTH cleaning system 702 is introduced into the separation system 706 for the separation and drying of the particles of the MOUTH. Cleaning system 702 is greater share of the costs associated with obtaining particles of the MOUTH when using conventional methods. Cleaning system 702 in the General case includes a system for adding water/exchange 708, the system dissolving 710, the system hydrogenation 712 and three separate crystallization capacity a, b, c. In the system of adding water/exchange 708 significant portion of the mother liquor displace water. After adding water, the suspension is water/HUNDRED injected into the system dissolving 710, where a mixture of water/one HUNDRED and heat up until the HUNDRED particles in the water is completely dissolved. After dissolution of the HUNDRED and the HUNDRED solution in water is subjected to hydrogenation in a hydrogenation system 712. After that, the exhaust flow hydrogenation product from the hydrogenation 712 spend three stages of crystallization in the crystallization tanks a, b, c followed by the separation of the MOUTH in the separation system 706.

Figure 35 illustrates the improved method of obtaining a MOUTH using bubbling reactor column oxidation 800 configured in accordance with a variant implementation of the present invention. From the reactor 800 select the initial suspension, the soda is containing solid particles HUNDRED and liquid mother liquor. Usually the initial slurry may contain solid particles HUNDRED in number, in the range of from about 10 to about 50 weight percent, and the balance is a liquid mother liquor. Solid particles HUNDRED present in the original suspension, usually contain at least about 400 hours/mn (wt.) 4-carboxyanhydride (4-CBA), more often at least about 800 hours/mn (wt.) 4-CBA, and most often 4-CBA in the amount ranging from 1000 to 15000 h/mn (wt.). The initial suspension taken from the reactor 800, is introduced into the purification system 802 to reduce the concentration of 4-CBA and other impurities present in a HUNDRED. In the cleaning system 802 receives more pure/purified suspension and it is subjected to separation and drying in the separation system 804, thereby obtaining particles more pure solid terephthalic acid containing less than approximately 400 hours/mn (wt.) 4-CBA, more preferably less than about 250 h/mn (wt.) 4-CBA, and most preferably 4-CBA in the amount in the range from 10 to 200 h/mn (wt.).

Cleaning system 802 of the system receiving MOUTH, illustrated in figure 35, achieves several advantages in comparison with cleaning system 802 of the system of the prior art, is illustrated in figure 34. Suppose the equipment cleaning system 802 in General includes the exchange system solution 806, heat exchanger 808 and one mold 810. In the exchange system solution 806, at least about 50 mass percent of the mother liquor present in the original suspension, exchanged for fresh solvent replacement with obtaining, thus, suspensions after exchanging the solvent containing particles of one HUNDRED and solvent replacement. Suspension after exchanging the solvent, leaving the exchange system solution 806, is introduced into the heat exchanger (or the secondary oxidation reactor) 808. In the heat exchanger 808 reaction secondary oxidation is carried out at somewhat higher temperatures in comparison with those used during the reaction the initial/the primary oxidation carried out in a bubbling reactor column 800. As discussed above, a large specific surface area, small particle size and low density of particles HUNDRED, obtained in the reactor 800, lead to the fact that certain impurities captured in the HUNDRED particles are available for oxidation in the heat exchanger 808 without any need for complete dissolution of the particles HUNDRED in the exchanger 808. Thus, the temperature in the heat exchanger 808 may be less than in many similar methods of the prior art. Secondary oxidation conducted in the heat exchanger 808, preferably leads to the decrease is the concentration of 4-CBA in a HUNDRED, at least 200 hours/mn (wt.), more preferably, at least about 400 hours/mn (wt.), and most preferably in an amount in the range from 600 to 6000 h/mn (wt.). Preferably the temperature of the secondary oxidation in the heat exchanger 808, at least about 10°C higher than the temperature of the primary oxidation bubbling reactor colon 800, more preferably higher than the temperature of the primary oxidation reactor 800 on a value in the range from approximately 20 to approximately 80°C., and most preferably higher than the temperature of the primary oxidation reactor 800 on a value in the range from 30 to 50°C. the temperature of the secondary oxidation preferably is in the range from about 160 to about 240°C., more preferably in the range of from about 180 to about 220°C., and most preferably in the range of from 190 to 210°C. the Purified product of the heat exchanger 808 requires only one stage of crystallization in the mold 810 before carrying out the separation in the separation system 804. Suitable methods of secondary oxidation/disposal are discussed in more detail in the publication of the patent application U.S. No. 2005/0065373, the description of which in its entirety clearly is incorporated herein by reference.

Terephthalic acid (example is, MOUTH), obtained using the system illustrated in figure 35, it is preferable to form particles of the MOUTH, characterized by an average particle size equal to at least about 40 microns, more preferably in the range from about 50 to about 2000 microns, and most preferably in the range of from 60 to 200 microns. Particles MOUTH preferably characterized by an average specific surface area according to BET method, of less than approximately 0.25 m2/g, more preferably in the range from approximately 0.005 to approximately 0.2 m2/g, and most preferably in the range from 0.01 to 0.18 m2/, MOUTH, obtained using the system illustrated in figure 35, is suitable for use as feedstock in obtaining a PET. Usually PET receive as a result of the esterification of terephthalic acid with ethylene glycol, followed by polycondensation. Preferably terephthalic acid, obtained in accordance with one implementation of the present invention, used as a source of feed material in the method of obtaining a PET in a tubular reactor described in patent application U.S. serial number 10/013318, filed December 7, 2001, the description of which in the present its entirety is incorporated herein by reference.

Particles HUNDRED, with preferred morphology described herein are particularly suitable for use in the above-described method of oxidative disposal, designed to reduce the content of 4-CBA. In addition, these preferred particles HUNDRED ensure the achievement of benefits in a wide range of other ways for further processing, including the dissolution and/or chemical reaction of the particles. These additional methods of further processing include, but are not limited to these: the reaction of at least one hydroxyl-containing compound with obtaining derivatives of esters, in particular, the reaction of one HUNDRED with methanol to obtain terephthalate and impurity esters; the reaction of at least one diola obtaining monomers of ester and/or a polymeric derivative of ester, in particular, the reaction of one HUNDRED with ethylene glycol to obtain a polyethylene terephthalate (PET); and full or partial dissolution in solvents, including the following, but not limited to these are: water, acetic acid and N-methyl-2-pyrrolidone, which may include additional processing, including the following, but is not limited to only these: eresident purer terephthalic acid and/or selective chemical reduction of carbonyl groups, other than carboxylic acid groups. In particular, included essentially the dissolution of a HUNDRED in a solvent, including water, in combination with partial hydrogenation, which leads to the reduction of aldehydes, in particular, 4-CBA, fluorenone, phenonom and/or anthraquinones.

The inventors also envisage the possibility of obtaining particles of a HUNDRED, having the preferred properties described herein, of particles of a HUNDRED who do not meet the preferred properties described herein (particles HUNDRED that do not meet the requirements, using methods that include the following, but is not limited to only these: mechanical grinding particles HUNDRED, noncompliant, and full or partial dissolution of the particles of a HUNDRED that do not meet the requirements, with subsequent complete or incomplete presidenial.

In accordance with one implementation of the present invention proposes a method for partial oxidation of oxidizable aromatic compounds to obtain one or more types of aromatic carboxylic acids, where the degree of purity of the formed solvent parts of the original feed material (i.e., "formed by the solvent source supplied material") and the degree of purity of the formed oxidized is Obedinenie part of the original feed material (i.e., "formed by oxidative coupling of the source of submitted material") govern in certain ranges, these next. Together with other variants of implementation of the present invention makes it possible to regulate the degree of purity of the liquid phase and, if any, of the solid phase and the joint phase of the suspension (i.e. the solid phase plus liquid phase reaction medium in certain preferred ranges indicated below.

As regards formed by the solvent of the original feed material, it is known oxidation of oxidizable aromatic compounds (compounds) to obtain an aromatic carboxylic acid, where the formed solvent source the feed material introduced into the reaction medium is a mixture of acetic acid and water with grades of "pure for analysis", and it is often used in laboratory scale and pilot plant scale. Likewise known an oxidation of oxidizable aromatic compounds to obtain an aromatic carboxylic acid, where the solvent leaving the reaction medium is separated from the resulting aromatic carboxylic acid, and then sent for recycling back into the reaction medium as a solvent in the original feed material mainly for reasons connected with the production cost. This shipment solvent for recycling over time when the result in accumulation in sent to recycling the solvent of certain impurities from the source feed material and by-products of the process. State of the art there are various ways to assist with clearance sent to recycling the solvent before re-introduction into the reaction medium. In General high degree of purification sent to recycling of the solvent results in a significantly higher production cost in comparison with what is achieved by a reduced degree of purification when using such methods. One embodiment of the present invention relates to the understanding and definition of the preferred ranges for a large number of impurities in the formed solvent source feed material, many of which until this time was perceived as mostly harmless, in order to find the optimal balance between the total production cost and the total degree of purity of the product.

"Sent for recycling from solvent source supplied material" is defined herein as formed by the solvent source the feed material comprising at least about 5 mass percent mass, which was previously perepustili through the reaction medium containing one or more oxidizable aromatic compounds, undergoes partial oxidation. For reasons connected with the fill factor R is storyteller and the duration of the operating cycle for a production plant, it is preferable that the part sent to recycling the solvent was perepustili through the reaction medium at least once daily functioning, more preferably at least once a day for at least seven consecutive days of operation, and most preferably at least once a day for at least 30 consecutive days of operation. For economic reasons it is preferable for the solvent to be sent to recycling, would constitute at least about 20 weight percent formed from a solvent source feed material directed into the reaction medium of the present invention, more preferably, at least about 40 weight percent, even more preferably at least about 80 weight percent, and most preferably at least 90 mass percent.

The inventors have discovered that for reasons connected with the activity in the reaction, and to account for the presence of metal impurities remaining in the oxidation product, the concentration of selected polyvalent metal sent for recycling from solvent source feed material are preferably in the ranges shown immediately below. Concentration is Oia iron sent to recycling the solvent is preferably an amount less approximately 150 hours/mn (wt.), more preferably lower by approximately 40 hours/mn (wt.), and most preferably in the range from 0 to 8 h/mn (wt.). Nickel concentration in sent to recycling the solvent preferably has a value of less than approximately 150 hours/mn (wt.), more preferably lower by approximately 40 hours/mn (wt.), and most preferably in the range from 0 to 8 h/mn (wt.). The concentration of chromium in sent to recycling the solvent preferably has a value of less than approximately 150 hours/mn (wt.), more preferably lower by approximately 40 hours/mn (wt.), and most preferably in the range from 0 to 8 h/mn (wt.). The concentration of molybdenum in sent to recycling the solvent preferably has a value of less than about 75 hours/mn (wt.), more preferably less approximately 20 hours/mn (wt.), and most preferably in the range from 0 to 4 h/mn (wt.). The concentration of titanium in sent to recycling the solvent preferably has a value of less than about 75 hours/mn (wt.), more preferably less approximately 20 hours/mn (wt.), and most preferably in the range from 0 to 4 h/mn (wt.). Copper concentration in sent for recycling solvent suppose the equipment has value less approximately 20 hours/mn (wt.), more preferably less approximately 4 h/mn (wt.), and most preferably in the range from 0 to 1 h/mn (wt.). Sent in for recycling the solvent is usually also contains other metal-containing impurities in the General case when the variation of content to even lower levels in the form of shares from one or more of the above metals. Regulation of the content of the above metals during curing in the preferred ranges will ensure the keeping of the content of other metal-containing impurities at appropriate levels.

These metals can be detected as impurities in any of the applicants in process original filed flows (for example, in the incoming oxidizable compound, the solvent, the oxidizing agent and the compounds of the catalyst). Alternatively, the metals can be formed as corrosion products in any of the processing units in contact with the reaction medium and/or in contact with sent to recycling the solvent. Methods of regulation of the metal content during curing in the described concentration ranges include ensuring appropriate technical characteristics and tracking purity on the I different source of supply of materials and the proper use of structural materials, includes the following, but not limited to only these: many commercial brands of titanium and stainless steels, including those brands that are known under the name of two-phase stainless steels and vysokoporodistyh stainless steel.

The inventors have also identified the preferred ranges for selected aromatic compounds in sent to recycling the solvent. These compounds include both precipitated and dissolved aromatic compounds in sent to recycling the solvent.

Surprisingly, but every precipitated product (e.g., TPA), obtained by partial oxidation of para-xylene, is a contaminant in respect of which it is necessary to take measures in case of solvent sent to recycling. Because, surprisingly, levels of solids in the reaction medium, there are preferred ranges, any precipitated product formed by the solvent source feed material directly reduces the amount of oxidizable compounds, which can be submitted along with him. In addition, as was found, the flow of precipitated solid phase formed by the TRA, sent to recycling the solvent at elevated levels has an adverse impact on the character of the particles, obrazu what's in the environment precipitation oxidation, which leads to giving unwanted nature of operations at the subsequent stages of the technological scheme (for example, filter the product, wash solvent, oxidation recycling of raw crude product, dissolving crude crude product for further processing, and the like). Another undesirable characteristic of the precipitated solids are sent to recycling the formed solvent source feed material is that it often has very high levels of precipitated impurities in comparison with the concentrations of impurities in the volume of the solid phase in suspensions TRA, of which a large number are sent to recycling the solvent. Possible increased concentrations of impurities observed in the solid phase suspended in the sent to recycling the filtrate, can relate to the time of nucleation, suitable for the deposition of certain impurities from sent to recycling the solvent and/or cooling are sent to recycling the solvent, either intentional or caused losses to the environment. For example, the concentration vysokoochishchennogo and unwanted 2,6-dicarboxylate was observed at much higher levels in the solid phase present in the sent is for recycling the solvent at 80°C, in comparison with what was observed in the solid phase TRA separated from the ship to the recycling of the solvent at 160°C. similarly, the concentration of isophthalic acid was observed at much higher levels in the solid phase present in the sent to recycling the solvent, in comparison with the levels observed in the solid phase TRA from the reaction environment. How exactly will behave a particular precipitated impurities captured in sent to recycling the solvent, with the re-introduction into the reaction medium, apparently, is a variable property. It depends maybe on the relative solubility of the impurity in the liquid phase reaction medium, can be how the besieged admixture forms layers of precipitated solid phase, and can be from the local deposition rate TRA where the solid phase is first re-introduced in the reaction medium. Thus, the inventors have found that the regulation of the level of certain impurities in sent for recycling solvent as described hereinafter, is useful regardless of whether these impurities to be sent in for recycling the solvent in the dissolved form, or they will be captured in the particles.

The quantity of precipitated solid phase present is sent in for recycling the filtrate, determined using the gravimetric method in the following way. Of the solvent, supplied in a reaction medium selected a representative sample at a time, as the solvent perepuskat in the channel in the direction of the reaction medium. A suitable sample size of approximately 100 grams, placed in a glass container containing approximately 250 ml of the inner volume. Before the release in terms of atmospheric pressure, but with simultaneous continuous propuskanii in the direction of the container for the sample to be sent to recycling the filtrate is cooled to less than 100°C.; the cooling produce in order to limit the evaporation of the solvent in a short period of time before a sealed closure in a glass container. After placing the sample in terms of atmospheric pressure glass container is immediately sealed. After that, the sample allow to cool to about 20°C and surrounded by air at a temperature of approximately 20°C, and in the absence of forced convection. After reaching approximately 20°C. the sample is kept in this state for at least about 2 hours. Then hermetically sealed container is strongly shaken until then, until you get isolino homogeneous distribution of the solid phase. Directly after that, the container for the sample is placed magnetic stirrer and ensure its rotation at a speed sufficient to effectively withstand uniform distribution of the solid phase. Pipetted and weighed aliquot of 10 ml of a mixed liquid containing suspended solid phase. After that, the volume of the liquid phase from this aliquot is separated in the distillation under vacuum still at approximately 20°and efficiency, to avoid loss of the solid phase. Wet the solid phase is filtered from this aliquot, then dried with efficiency, to avoid sublimation of the solid phase, and this dried solids weighed. The relationship between the mass of the dried solid phase and the mass of the initial aliquot of the suspension represents a fraction of the solid phase, usually expressed in the form of a percentage and referred to in this document levels of precipitated solid phase in the filtrate is sent to recycling, at 20°C.

The inventors have discovered that aromatic compounds dissolved in the liquid phase reaction medium and comprising aromatic carboxylic acid having no non-aromatic hydrocarbonrich groups (for example, isophthalic acid, benzoic acid, phthalic KIS the GTC, 2,5,4'-tricarboxymethyl), surprisingly, are harmful components. Despite the fact that these compounds have greatly reduced reactivity in this reaction medium in comparison with oxidizable compounds having non-aromatic gidrolabilna group, the inventors have found that these compounds, however, take part in numerous adverse reactions. Thus, it is advantageous to regulate the levels of these compounds in the liquid phase reaction medium during curing in the preferred ranges. This leads to the definition of the preferred ranges of selected compounds in sent for recycling from solvent source feed material, and the preferred ranges of selected precursors in the formed oxidizable aromatic compound source feed material.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain terephthalic acid (TPA), the inventors have found that vysokoosnaschenny and undesirable impurity 2,7-dicarboxylate (2,7-DCF) is almost not detected in the reaction medium and the selected product in the presence of meta-substituted aromatic compounds in the reaction medium at very low levels soda is Jania. The inventors have discovered that the presence in the formed solvent source feed material impurity isophthalic acid at increasing the levels of efficiency of formation of 2,7-DCF increases almost in direct proportion. The inventors also found that the presence in the original feed material, formed para-xylene, impurity meta-xylene efficiency education 2,7-DCF again increases almost in direct proportion. In addition, even in the absence of the formed solvent source feed material and formed by oxidative coupling of the source feed material meta-substituted aromatic compounds, the inventors have found that during a typical partial oxidation of very pure para-xylene is produced a certain amount of isophthalic acid, especially when in the liquid phase reaction medium is benzoic acid. This soobrazuyas isophthalic acid due to its higher solubility, in comparison with TPA, in a solvent containing acetic acid and water, over time, can accumulate in commercial installations, which are sent to recycling the solvent. Thus, all the characteristics selected from the number softala the Oh of the acid formed by the solvent of the original feed material, the number of meta-xylene in the formed oxidizable aromatic compound source feed material and the speed of self-isophthalic acid in the reaction medium, if appropriate, are considered in equilibrium with each other and in balance with any reactions that provide the expenditure of isophthalic acid. As it was found, in addition to the formation of 2,7-DCF isophthalic acid undergoes and other spending her reaction, as described next. In addition, the inventors have discovered that there are other issues that require attention in the case of an assignment of suitable ranges for the meta-substituted aromatic compounds by the incomplete oxidation of para-xylene to receive TRA. Other vysokoosnaschenny and undesirable impurities, such as 2,6-dicarboxylate (2,6-DCF), seems to be very closely related to dissolved para-substituted aromatic compounds, which are always present in the desired para-xylene original feed material is directed to liquid-phase oxidation. Thus, the suppression of the formation of 2,7-DCF is best seen in the perspective of communication with levels of other formed colored impurities.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain TRA inventors have discovered that p is increasing levels of isophthalic acid and phthalic acid in the reaction medium increases the efficiency of education trimellitic acid. Trimellitate acid is trifunctional carboxylic acid, the presence of which leads to branching of polymer chains during retrieval PET from TRA. In many applications of PET levels of branching should be regulated in maintaining low levels, and thus, the regulation trimellitic acid should ensure maintaining low levels in purified TPA. The presence of meta-substituted and ortho-substituted compounds in the reaction medium in addition to providing education trimellitic acid also becomes the cause of education and other tricarboxylic acids (e.g., 1,3,5-tricarboxylate). In addition, the increasing presence in the reaction medium tricarboxylic acids leads to an increase in the efficiency of education tetracosanoic acids (for example, 1,2,4,5-tetracarboxylate). One factor when setting the preferred levels of meta-substituted and ortho-substituted compounds are sent to recycling formed by the solvent of the original feed material, formed by oxidative coupling of the source feed material and reaction medium corresponding to the present invention is the regulation of the efficiency of the total education of all aromatic carboxylic acids having more than on the e group of carboxylic acid.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain TRA inventors have found that elevated levels in the liquid phase reaction medium short dissolved aromatic carboxylic acids that do not have non-aromatic hydrocarbonrich groups directly lead to increased efficiency of formation of carbon monoxide and carbon dioxide. This increased the efficiency of formation of oxides of carbon represents the loss of output, both in terms of oxidant, and oxidizable compounds, the latter being due to the fact that many of the passing of the obtained aromatic carboxylic acids, on the one hand, can be considered as impurities, on the other hand, they also have commercial value. Thus, the proper removal of relatively soluble carboxylic acids that do not have non-aromatic hydrocarbonrich groups, sent to recycling the solvent has an economic value in preventing loss of output in both oxidizable aromatic compound and an oxidant, in addition to the suppression of education in the highest degree undesirable impurities, such as various fluorenone and trimellitate acid.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain TRA is subretinal found that, education 2,5,4'-tricarboxymethyl, apparently, is inevitable. 2,5,4'-tricarboxymethyl represents an aromatic tricarboxylic acid, formed in the result of the coupling of two aromatic rings may be the result of pairing dissolved para-substituted aromatic compounds with aryl radical, maybe with aryl radical formed in the decarboxylation or decarbonylation para-substituted aromatic compounds. Fortunately, education 2,5,4'-tricarboxymethyl is usually to lower levels in comparison with trimellitic acid, and it usually does not cause a significant increase in difficulty due to branching of polymer molecules, while obtaining PET. However, the inventors have found that elevated levels 2,5,4'-tricarboxymethyl in the reaction medium, comprising the oxidation of alkylaromatic in accordance with a preferred variant implementation of the present invention, lead to higher levels of vysokoochishchennogo and unwanted 2,6-DCF. Elevated levels of 2,6-DCF may be formed with the participation of 2,5,4'-tricarboxymethyl in the circuit loop with loss of a water molecule, although the exact reaction mechanism not known for sure. If 2,5,4'-tricarboxylate is l, which is more soluble in the solvent containing acetic acid and water, in comparison with TPA, will be able to accumulate in sent to recycling the solvent to extremely high levels, then the degree of conversion of 2,6-DCF can become unacceptably large.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain TRA inventors have found that an aromatic carboxylic acid having no non-aromatic hydrocarbonrich groups (e.g., isophthalic acid) in the General case leads to a mild suppression of the chemical activity of the reaction medium in the presence in the liquid phase at a sufficient concentration.

For example, in the case of liquid-phase partial oxidation of para-xylene to obtain TRA inventors have found that the deposition is very often non-ideal (i.e. non-equilibrium) in terms of the relative concentrations of various chemical compounds in the solid phase and in the liquid phase. May be this is due to the fact that the deposition rate is very high when the reaction rate in one pass per unit of time, preferred in the present document, which leads to imperfect coprecipitation of impurities, or even occluding. Thus, in the case of the desirability of limiting the concentration determined what's impurities (for example, trimellitic acid and 2,6-DCF) in crude crude TPA in connection with the configuration operations on the subsequent stages of the technological scheme is preferred to adjust their concentration in the formed solvent source feed material and the speed of their formation in the reaction medium.

For example, the inventors have found that benzophenone connection (for example, 4,4'-dicarbocyanine and 2,5,4'-tricarbocyanine)received during the partial oxidation of para-xylene, are undesirable effect in the reaction medium to obtain a PET, even though benzophenone connections themselves are not so vysokoklassnymi in TRA as such are fluorenone and anthraquinones. Accordingly, it is desirable to limit the presence of benzophenone and elected predecessors sent in for recycling the solvent and formed oxidizable compound the original feed material. In addition, the inventors found that the presence of elevated levels of benzoic acid, regardless of whether she typed in sent to recycling the solvent or formed in the reaction medium leads to increased rates of receipt of 4,4'-dicarbocyanine.

Generally speaking, the inventors have discovered and sufficiently quantitatively Okha who was acharitable amazing array of reactions for aromatic compounds, not having a non-aromatic hydrocarbonrich groups that take place in the case of liquid-phase partial oxidation of para-xylene to receive TRA. Summarizing just the results for individual cases associated with benzoic acid, the inventors have found that elevated levels of benzoic acid in the reaction medium of certain variants of realization of the present invention lead to a significant increase in the efficiency of education vysokokratnoy and unwanted 9-fluorenone-2-carboxylic acid, to obtain significantly elevated levels of 4,4'-dicarboxylate, to obtain high levels of 4,4'-dicarbocyanine, soft suppression chemical activity when the target oxidation of para-xylene and to providing exceptional levels of oxides of carbon and concomitant loss of output. The inventors have found that elevated levels of benzoic acid in the reaction medium also leads to increased efficiency of education isophthalic acid and phthalic acid, the levels of which are desirable in the case of control, soaking in the low band in accordance with this aspect of the present invention. The number and importance of reactions involving benzoic acid, can be an even more surprising is sustained fashion, because some inventors recently include using benzoic acid instead of acetic acid as a main component of the solvent (see, for example, U.S. patent No. 6562997). In addition, the inventors of the present invention have observed that during the oxidation of para-xylene benzoic acid soobrazuya with speeds that are quite significant in comparison with its formation of impurities, such as toluene and ethylbenzene, are usually detected in the formed oxidized compound source feed material containing para-xylene technical purity.

On the other hand, the inventors have found minor importance for more regulation of the composition to be sent to recycling the solvent in regard to the presence of oxidizable aromatic compounds, and in regard to intermediates in the reaction of aromatics, which remain non-aromatic gidrolabilna group, and are also relatively soluble in the solvent, are sent to recycling. In General these compounds are either served in the reaction environment, or they are formed in the reaction medium, with speeds corresponding to a significant excess of the level of their presence in sent to recycling the solvent; and the speed of rashodovany the data connections in the reaction medium is large enough, while maintaining one or more non-aromatic hydrocarbonrich groups, which makes it possible to appropriately limit their accumulation in sent to recycling the solvent. For example, during the partial oxidation of para-xylene in a multiphase reaction medium, together with large quantities of solvent to a limited extent evaporates and para-xylene. In the case of abandonment, the data of the evaporated solvent reactor as part of the exhaust gas and its condensation to extract the solvent sent to recycling, here is condensed and also a substantial part of the evaporated para-xylene. There is no need to limit the concentration of the para-xylene in the solvent sent to recycling. For example, if you leave the suspension of the reaction medium in the oxidation of para-xylene solvent from the solid phase is separated, then this extracted solvent will contain a concentration of dissolved pair-Truelove acid, such concentrations that exist at the time of removal from the reaction medium. Despite the fact that the restriction of a stationary concentration of para-Truelove acid in the liquid phase reaction medium, see below, may be important, see below, there is no need for a separate regulation of the content of para-Truelove acid in this hour and sent to recycling the solvent because of its relatively good solubility and its low mass flow in comparison with the formation of pair-Truelove acid in the reaction medium. Similarly, the inventors have found little reason to limit concentrations in sent to recycling the solvent of aromatic compounds having methyl substituents (for example, Truelove acids), aromatic aldehydes (for example, terephthalic aldehyde, aromatic compounds having hydroxymethylene substituents (for example, 4-hydroxymethylbenzene acid) and brominated aromatic compounds, while retaining at least one non-aromatic hydrocarbonous group (for example, alpha-bromo-para-Truelove acid) levels, lower in comparison with those inherent in the liquid phase leaving the reaction environment, which exists when partial oxidation of xylene in accordance with a preferred variant implementation of the present invention. Surprisingly, however, the inventors have also discovered that there is no need in regulation sent to recycling the solvent concentration of selected phenols formed during the partial oxidation of xylene in accordance with its very nature, since these compounds are formed and dissolved in the reaction medium with velocities corresponding to a considerable excess of the level of their presence in the solvent sent to recycling. For example, the inventors have found is about, 4-hydroxybenzoic acid has relatively small effect on the chemical activity in the preferred embodiments of the present invention in the case of joint filing with the costs corresponding to more than 2 grams of 4-hydroxybenzoic acid in 1 kg of para-xylene, which is much higher than the natural presence sent to recycling the solvent, although other researchers have reported that it is essential poison in such reaction medium (see, for example, the work of W. Partenheimer, Catalysis Today 23 (1995) p. 81).

Thus, there are numerous reactions and numerous considerations for specifying the preferred ranges for the various aromatic impurities in the formed solvent source feed material, as currently described. These findings formulated in the expression of the total bulk composition of all threads in the solvent supplied into the reaction medium during a predetermined period of time, preferably one day, preferably one hour, and most preferably one minute. For example, if one formed by the solvent source submitted material will be bypassed essentially continuously with composition corresponding to 40 hours/mn (wt.) isophthalic acid, at a flow rate of 7 kg is s per minute, the second formed by the solvent source submitted material will be bypassed essentially continuously with composition corresponding to 2000 h/mn (wt.) isophthalic acid, at a flow rate of 10 pounds per minute, and no other threads formed by the solvent source feed material in the reaction environment do not, then the aggregate bulk composition for formed by solvent source feed material will count as(40*7+2000*10)/(7+10)=1193 h/mn (wt.) isophthalic acid. It should be noted that the weight of any formed by oxidative coupling of the source of submitted material or any oxidant formed by the original feed material, which may be mixed with the formed solvent source feed before entering the reaction medium, is not taken into account when calculating the total bulk composition formed by the solvent of the original feed material.

The following table 1 represents the preferred values for certain components in the formed solvent source feed material introduced into the reaction environment. Components formed by the solvent of the original feed material, are shown in table 1 represent the following: 4-carbon benzaldehyde (4-CBA), 4,4'-dicarbonitrile (4,4'-DCS), 2,6-dicarboxaldehyde (2,6-DCA), 2,6-dicarboxylate (2,6-DCF), 2,7-dicarboxylate (2,7-DCF), 3,5-dicarboxylate (3,5-DCF), 9-fluorenone-2-carboxylic acid (9F-2CA), 9-fluorenone-4-carboxylic acid (9F-4CA), the total range of fluorenone, including other fluorenone not listed individually (total range of fluorenone), 4,4'-dicarboxyethyl (4,4'-DCB), 2,5,4'-tricarboxymethyl (2,5,4'-TCB), phthalic acid (RA), isophthalic acid (IPA), benzoic acid (BA), trimellitate acid (TMA), 2,6-dicarboxylicacid (2,6-DCBC), 4,4'-dicarboxyethyl (4,4'-DCBZ), 4,4'-dicarbocyanine (4,4'-DCBP), 2,5,4'-tricarbocyanine (2,5,4'-the air bypass section), terephthalic acid (TPA), the precipitated solid phase at 20°C and the total range of aromatic carboxylic acids not having a non-aromatic hydrocarbonrich groups. The following table 1 represents the preferred amounts of these impurities in a HUNDRED, obtained in accordance with the variant of realization of the present invention.

TABLE 1
Components formed by the solvent source feed material introduced into the reaction medium
Component identificationThe preferred amount of (h/mn (wt.))The most preferred quantity (h/mn (wt.))
4-CBA<120030-60060-300
4,4'-DCS<3<2<1
2,6-DCA<60,1-30,2-1
2,6-DCF<200,1-100,5-5
2,7-DCF<100,1-50,5-2
3,5-DCF<10<5<2
9F-2CA<100,1-50,5-2
9F-4CA<5<3<1
Comprehensive range of fluorenone <40<201-8
4,4'-DCB<45< 150,5-5
2,5,4'-TCB<450.1 to 150,5-5
PA<100015-40040-150
IPA250040-1200120-400
BA<450050-1500150-500
TMA<100015-40040-150
2,6-DCBC<40<20<5
4,4'-DCBZ<40<20<5
4,4'-DCBP<40<20<5
2,5,4'-the air bypass section<40 <200,5-5
TPA<9000200-6000400-2000
The precipitated solid phase at 20°C<9000200-6000600-2000
Comprehensive range of aromatic carboxylic acids that do not have non-aromatic hydrocarbonrich groups<18000300-9000450-3000

Sent in for recycling the solvent is usually present also many other aromatic impurities, in General, when the variation of content to even lower levels and/or share content from one or more of the described aromatic compounds. Methods of regulation of the levels described aromatic compounds during curing in the preferred ranges will usually ensure adherence to appropriate levels and other aromatic impurities.

In the case of use in the reaction medium bromine, as is well known, a large number of ionic and organic forms of bromine will exist in a dynamic equilibrium. Data of various forms of bromine are characterized by different the mi characteristics stability immediately after leaving the reaction medium and passing through the operations in a variety of settings, related to be sent to recycling the solvent. For example, alpha-bromo-para-tolarova acid under certain conditions may be present as such or in other conditions may be subjected to hydrolysis with the formation of 4-hydroxymethylbenzene acid and hydrogen bromide. In the present invention is preferred that at least about 40 weight percent, more preferably at least about 60 weight percent, and most preferably at least about 80 weight percent of the total weight of bromine present in the aggregate formed by the solvent source feed material introduced into the reaction environment, would have a view of one or more of the following chemical forms: ionic bromine, alpha-bromo-para-tolarova acid and brooksyne acid.

Although the importance and value of regulation total mass-average degree of purity from a solvent source feed material during curing is described in desirable ranges of the present invention have hitherto not been disclosed and/or described, appropriate ways of regulating the degree of purity of the formed solvent source feed material can be composed of different ways, already known from the belt prior art. First, any solvent evaporated from the reaction medium, usually characterized by an appropriate degree of purity with the proviso that the liquid or solid phase of the reaction medium will not be captured evaporated solvent. In accordance with the description herein such capture properly restricts the flow of the drops of solvent medium irrigation in the space separating the exhaust gas over the reaction environment; and that the exhaust gas can be condensed sent to recycling the solvent with a suitable degree of purity in relation to aromatic compounds. Second, more difficult and expensive purification sent to recycling the formed solvent source feed material generally refers to the solvent taken from the reaction medium in liquid form, and to the solvent, which is subsequently comes into contact with liquid and/or solid phase reaction medium selected from the reaction vessel (i.e. sent to recycling the solvent obtained from the filter, in which the solid phase is concentrated and/or washed, sent to recycling the solvent obtained from the centrifuge, in which the solid phase is concentrated and/or washed, sent to recycling the solvent selected with crystallization, and the like). Though the state of the art known methods for clean-up required data are sent to recycling the solvent flows using one or more descriptions of the prior art. With regard to the regulation of the levels of precipitated solids are sent to recycling the solvent during curing within the specified ranges, then suitable methods of control include, but are not limited to these: gravimetric sedimentation, mechanical filtration using filter cloth on a rotating belt filters and rotary drum filters, mechanical filtering using fixed filter medium inside the vessels working under pressure, hydrocyclones and centrifuges. With regard to the regulation of the level of dissolved aromatic compounds in sent to recycling the solvent during curing within the specified ranges, the methods of control include, but are not limited to these: the methods described in U.S. patent No. 4939297 and the publication of the patent application U.S. No. 2005-0038288 included in this document for reference. However, none of these inventions of the prior art does not disclose and does not describe the preferred levels of purity in the aggregate formed by the solvent of the original feed material, as described herein. Instead, these inventions of the prior art simply offer ways is s cleaning elected and private flows are sent to recycling the solvent without removing the optimal values of the present invention for the composition of aggregate bulk from the solvent source supplied material introduced into the reaction environment.

Turning now to the purity of the original feed material, formed by oxidative coupling, we can say that it is known that in this case there are certain levels of isophthalic acid, phthalic acid and benzoic acid, and at low levels, the presence of these compounds in the purified TPA is used to obtain the polymer is valid. In addition, it is known that these compounds are relatively more soluble in many solvents, and in the best case they can be removed from the purified TPA using methods of crystallization. However, embodiments of the invention described herein, at the moment it is known that the regulation of the levels of several relatively soluble aromatic compounds, namely, compounds comprising isophthalic acid, phthalic acid and benzoic acid in the liquid phase reaction medium, surprisingly, is important in regulating the levels of polycyclic and painted aromatic compounds formed in the reaction medium, in the regulation of the levels of compounds having in the molecule more than 2 functionality carboxylic acids, regulation of activity in the reaction the AI in the reaction medium for the partial oxidation and regulation of output losses in the ratio of oxidizer and aromatic compounds.

State of the art it is known that isophthalic acid, phthalic acid and benzoic acid formed in the reaction medium as follows. Impurity meta-xylene from the original feed material with a good degree of conversion and the output is oxidized to obtain IPA. Impurity ortho-xylene from the original feed material with a good degree of conversion and the output is oxidized to obtain phthalic acid. Impurity ethylbenzene and toluene from the original feed material with a good degree of conversion and the output is oxidized to obtain the benzoic acid. However, the inventors have found that in the reaction medium containing para-xylene, significant amounts of isophthalic acid, phthalic acid and benzoic acid are formed by mechanisms other than oxidation of meta-xylene, ortho-xylene, ethylbenzene and toluene. Data other inherent nature of the system chemical routes may include decarbonylation, decarboxylation, reorganization transition States and accession methyl and carbonyl radicals to aromatic rings.

When determining the preferred ranges of the levels of impurities in the source feed material formed oxidizable compound, is has many factors. Any impurity in the source supplied the material is likely to be associated with the direct loss of output and the cost of cleaning product if the requirements for the degree of purity to the product of oxidation will be tough enough (for example, in the case of the reaction medium for the partial oxidation of para-xylene toluene and ethylbenzene, usually found in the para-xylene technical purity, lead to the formation of benzoic acid, and this benzoic acid largely removed from most commercial options TRA). In case of participation of a product of partial oxidation of the impurities from the source material supplied in additional reactions when considering the magnitude of costs needed for the treatment of the source of submitted material become significant factors other than simple loss of output and delete (for example, in the case of the reaction medium for the partial oxidation of para-xylene, among other things, ethylbenzene leads to the production of benzoic acid, and benzoic acid then leads to vysokokratnoy 9-fluorenone-2-carboxylic acid, to obtain isophthalic acid, to obtain phthalic acid and to obtain high amounts of carbon oxides). In the case of self-education in the reaction environment, additional quantities of impurities by chemical mechanisms not directly related to impurities in the original feed material, the analysis becomes even more complex (for example, in the case of the reaction medium for a portion of the aqueous oxidation of para-xylene benzoic acid is also soobrazuya of the para-xylene). In addition, the processing of the raw crude oxidation product at the subsequent stages of the technological scheme may have an impact on the considerations in the preferred purity of the original feed material. For example, the costs required for the removal of direct additives (benzoic acid) and subsequent impurities (isophthalic acid, phthalic acid, 9-fluorenone-2-carboxylic acid, and the like) to appropriate levels, can be the same, may be different from each other and may be different from the requirements for the destruction of mostly unrelated impurities (for example, the product of partial oxidation of 4-CBA in the oxidation of para-xylene to obtain TRA).

The following describes the ranges of purity for the source of the feed material in the case of para-xylene are preferred when para-xylene is served in the reaction medium together with the solvent and oxidant in order partial oxidation to receive TRA. These ranges are preferable in the production method of TRA, which includes stages subsequent oxidation to remove from the reaction medium of impurities other than the oxidant and solvent (for example, metals of the catalyst). These ranges are even more preferred in the methods of obtaining the TRA, which provide the more destruction of one HUNDRED additional quantities of 4-CBA (for example, the result of turning one HUNDRED per terephthalate plus impurity esters and subsequent separation of complex methyl ester 4-CBA when using distillation, as a result of implementation of the methods of oxidative disposal, designed to transform 4-CBA TPA, as a result of implementation methods hydrogenation designed for the conversion of 4-CBA in the para-Truelove acid, which is then separated using methods of fractional crystallization). These ranges are the most preferred ways to receive TRA, which enables the removal of additional quantities of 4-CBA from a HUNDRED as a result of implementation of the methods of oxidative disposal, designed to transform 4-CBA TPA.

When using new knowledge about the preferred ranges for aromatic compounds that are sent for recycling, and about the relative amounts of aromatic compounds formed as a direct result of the oxidation of the impurities from the source feed material in comparison with others inherent in the nature of a system of chemical routes have been identified improved ranges for levels of impurities corresponding to the foul para-xylene fed to the process of partial oxidation to receive TRA. The following table 2 present the employed, the preferred values for the number of meta-xylene, ortho-xylene and ethyl benzene + toluene in the desired para-xylene original feed material.

Experts in the relevant field of technology at the moment should be aware that the above-mentioned impurities in contaminated para-xylene may exert their greatest impact on the reaction medium after the products of their partial oxidation will accumulate in sent to recycling the solvent. For example, flow top number of the most preferred range for the meta-xylene - 400 h/mn (wt.) - in the liquid phase reaction medium will immediately result in approximately 200 hours/mn (wt.) isophthalic acid in the operation when the level of solids in the reaction medium, is equal to approximately 33 mass%. This is comparable with the introduction of the top number of the most preferred range for the content of isophthalic acid in sent for recycling solvent, equal to 400 h/mn (wt.), when after cooling the reaction medium by evaporation of a typical solvent reaches approximately 1200 hours/mn (wt.) isophthalic acid in the liquid phase reaction medium. Thus, it is the accumulation over time of products of partial oxidation sent to recycling solution the body detects the largest possible effect of impurity meta-xylene, ortho-xylene, ethylbenzene and toluene from the original feed material, formed contaminated para-xylene. In accordance with this preferred that the above-mentioned ranges of impurities in the formed contaminated para-xylene original feed material was aged would be in for at least half of each day of operation during any reaction medium for partial oxidation in specific industrial installation, more preferably for at least three quarters of every day for at least seven consecutive days of operation, and the most preferable is the case where the mass-weighted average values for composition formed contaminated para-xylene original feed material are within the preferred ranges during the least 30 consecutive days of operation.

Methods of obtaining contaminated para-xylene is the preferred purity is already known state of the art, and they include, but are not limited to: distillation, ways incomplete crystallization at temperatures below the ambient temperature and the use of molecular sieves using the selective adsorption of defined pore size. However, predpochtitel the data ranges purity, specified in this document, at its upper edge require greater effort and cost in comparison with what is typical when using in practice commercial suppliers of para-xylene; and, however, at the lower edge preferred ranges avoid overly expensive options purification of para-xylene, intended for submission to the reaction medium for partial oxidation, due to the disclosure and description of what the combined action of self impurities from the para-xylene and reactions expenditure of impurities in the reaction medium becomes more significant parameter in comparison with the speed of feed impurities together with contaminated steam-xylene.

If the content in the stream killsometime the original feed material selected contaminants such as benzene and/or toluene, oxidation of these impurities can lead to the formation of benzoic acid. In accordance with the usage in this document the term "benzoic acid formed from impurities" shall mean benzoic acid produced during the oxidation of xylene from any source other than xylene.

As described herein, the portion of the benzoic acid produced during the oxidation of xylene, is formed from the xylene. This floor is the group of benzoic acid from xylene clearly occurs in addition to receiving any part of the benzoic acid, which can be a benzoic acid, formed from impurities. Wrong bind themselves by theory it appears that the benzoic acid formed in the reaction medium of xylene when various intermediate oxidation products of xylene spontaneously undergo decarbonylation (loss of carbon monoxide) or decarboxylation (loss of carbon dioxide) to produce, therefore, aryl radicals. These aryl radicals can split the hydrogen atom from one of the many available sources in the reaction medium and to produce a self-generated benzoic acid. Regardless of the chemical mechanism of the term "soobrazuyas benzoic acid in accordance with the usage in this document shall mean benzoic acid during the oxidation of xylene obtained from xylene.

As also described herein, in the case of oxidation of para-xylene to obtain terephthalic acid (TPA) obtaining self-generated benzoic acid leads to loss of output in relation to para-xylene and yield loss in respect of an oxidant. In addition, the presence of self-generated benzoic acid in the liquid phase reaction medium correlates with the increase in the role of many unwanted side reactions, namely the of aacci, including education vysokoodarennyh compounds called monocarboxylates. Soobrazuyas benzoic acid also contributes to the undesirable accumulation of benzoic acid in sent to recycling the filtrate, which further increases the concentration of benzoic acid in the liquid phase reaction medium. Thus, the formation of self-generated benzoic acid, it is desirable to minimize, but this situation properly also consider at the same time and in connection with the benzoic acid formed from the impurities, with the factors influencing the spending of benzoic acid, with factors associated with other points defining the selectivity of the reaction, and General economic indicators.

The inventors have found that self-benzoic acid can be adjusted during curing at low levels in the proper selection, for example, temperature, distribution of xylene and the availability of oxygen in the reaction medium during the oxidation. Without wanting to be bound by theory we can say that low temperatures and improved availability of oxygen, apparently, lead to a decrease in the velocity of decarbonylation and/or decarboxylation, which thus eliminates the aspect of loss of output due to self-generated Benz is Inoi acid. Sufficient availability of oxygen, apparently, direct reaction of aryl radicals in the direction of formation of other safer products, in particular hydroxybenzoic acids. The balance between the degree of conversion of aryl radicals in benzoic acid or hydroxybenzoic acid may also be influenced by the distribution of xylene in the reaction medium. Regardless of the chemical mechanisms, the inventors have identified the conditions of the reaction, which, despite its sufficient softness in reducing the efficiency of education benzoic acid, are fairly rigid in relation to the oxidation of a large proportion of the hydroxybenzoic acid to obtain monoxide and/or carbon dioxide, which are easily removed from the oxidation product.

In a preferred implementation of the present invention the oxidation reactor configured and operated so as to minimize the formation of self-generated benzoic acid and to maximize the oxidation of hydroxybenzoic acids to obtain monoxide and/or carbon dioxide. In the case of oxidation reactor for the oxidation of para-xylene to obtain terephthalic acid is preferred that the para-xylene would be at least approximately 50 m is sovich percent of total xylene in the flow of the original feed material, introduced into the reactor. More preferably para-xylene is at least about 75 weight percent of the total xylene in the flow of the original feed material. Even more preferably para-xylene is at least 95 mass% of the total xylene in the flow of the original feed material. Most preferably para-xylene is essentially the entire quantity of total xylene in the flow of the original feed material.

In the case of using the reactor for the oxidation of para-xylene to obtain terephthalic acid is preferred that the rate of formation of terephthalic acid would be maximized, while the rate of formation of self-generated benzoic acid would be minimized. Preferably the ratio between the rate of formation (based on mass) of terephthalic acid and the rate of formation (based on mass) self-generated benzoic acid is at least about 500:1, more preferably at least about 1000:1, and most preferably at least 1500:1. As will be demonstrated hereinafter, the rate of formation of self-generated benzoic acid is preferably measured when the concentration of benzoic acid in the liquid phase of reaction the th environment has value less 2000 h/mn (wt.), more preferably less 1000 h/mn (wt.), and most preferably less 500 h/mn (wt.), because these low concentrations provide suppression of reactions that convert benzoic acid to other compounds, suitable to low speed.

If you combine Samoobrona benzoic acid and benzoic acid, formed from impurities, the ratio between the rate of formation (based on mass) of terephthalic acid and the rate of formation (based on mass) of the total benzoic acid is preferably at least about 400:1, more preferably at least about 700:1, and most preferably at least 1100:1. As will be demonstrated later, the total rate of formation of self-generated benzoic acid plus benzoic acid formed from the impurities, preferably measured when the concentration of benzoic acid in the liquid phase reaction medium is less 2000 h/mn (wt.), more preferably less 1000 h/mn (wt.), and most preferably less 500 h/mn (wt.), because these low concentrations provide suppression of reactions that convert benzoic acid to other compounds, suitable to low speed.

As described in esteem document elevated concentrations of benzoic acid in the liquid phase reaction medium to increase the efficiency of the formation of many other aromatic compounds, some of which are harmful impurities in ENGLAND; and, as described herein, increased concentrations of benzoic acid in the liquid phase reaction medium to increase the efficiency of formation of gaseous oxides of carbon, the formation of which corresponds to a yield loss in respect of an oxidant and in respect of aromatic compounds and/or solvent. In addition, in the moment should disclose that the inventors have found that a significant proportion of this increased efficiency of formation of other aromatic compounds and oxides of carbon originates reactions that make possible the conversion of a certain number of molecules of benzoic acid, in contrast to the occasion catalysis benzoic acid other reactions without spending it the most. In line with this, "the resulting formation of benzoic acid" is defined herein as srednekraevoy mass of the total amount of benzoic acid, leaving the reaction medium, minus srednekraevoy mass of the total amount of benzoic acid supplied to the reaction medium during the same prom is a terrible time. This resulting formation of benzoic acid is often a positive, driving force for what is the rate of formation of benzoic acid formed from the impurities, and self-generated benzoic acid. However, the inventors have found that the rate of conversion of benzoic acid to carbon dioxide and several other compounds, apparently, approximately increases linearly as in the liquid phase reaction medium will increase the concentration of benzoic acid, measurement of when the other conditions of the reaction, including temperature, oxygen availability, the value of STR and activity in the reaction, properly withstand constant. Thus, if the concentration of benzoic acid in the liquid phase reaction medium is large enough, it may be due to the high concentration of benzoic acid in sent to recycling the solvent, then the degree of transformation of molecules of benzoic acid to other compounds, including oxides of carbon, may be of equal or greater value corresponding to the chemical formation of new molecules of benzoic acid. In this case, the result of the formation of benzoic acid balance can be achieved in the field of zero or even negative values. Inventors OBN is Ruili, if the resulting formation of benzoic acid is positive, then the ratio between the rate of formation (based on mass) of terephthalic acid in the reaction medium and the speed of the resulting formation of benzoic acid in the reaction medium, preferably in excess of about 700:1, more preferably in excess of about 1100:1, and most preferably greater than 4000:1. The inventors found that if the resulting formation of benzoic acid is negative, then the ratio between the rate of formation (based on mass) of terephthalic acid in the reaction medium and the speed of the resulting formation of benzoic acid in the reaction medium, preferably in excess of approximately 200:(-1), more preferably greater than about 1000:(-1), and most preferably greater than 5000:(-1).

The inventors have also identified the preferred ranges for the composition of the suspension (liquid + solid phase), taken from the reaction medium, and formed a solid one HUNDRED parts of the suspension. Preferred compositions of the suspensions and the preferred compositions HUNDRED, surprisingly, are excellent and suitable for use. For example, purified TRA obtained from this preferred HUNDRED as a result of oxidation in the waste utilization technologies, characterized by relatively low levels of total impurities and colored impurities, so that the purified TPA is suitable for use, without hydrogenation of additional quantities of 4-CBA and/or colored impurities, for a wide range of applications associated with the fibers of the PET, and applications associated with the packaging of PET. For example, a preferred composition of the suspension ensures the production of the liquid phase reaction medium, which is characterized by a relatively low concentration of significant impurities, and it meaningful way reduces the effectiveness of education other even more undesirable impurities, described in this document. In addition, in accordance with the other options in the implementation of the present invention, the preferred composition of the suspension significantly facilitate the further processing of the liquid from the suspension, which is sent for recycling solvent with a suitable degree of purity.

One HUNDRED and obtained in accordance with one implementation of the present invention, contains less impurities related to the selected types, in comparison with a HUNDRED, obtained using conventional methods and apparatus, namely those that use a solvent that is sent for recycling. Primes is, which may be present in a HUNDRED, include the following: 4-carboxybenzene (4-CBA), 4,4'-dicarbonitrile (4,4'-DCS), 2,6-dicarboxaldehyde (2,6-DCA), 2,6-dicarboxylate (2,6-DCF), 2,7-dicarboxylate (2,7-DCF), 3,5-dicarboxylate (3,5-DCF), 9-fluorenone-2-carboxylic acid (9F-2CA), 9-fluorenone-4-carboxylic acid (9F-4CA), 4,4'-dicarboxyethyl (4,4'-DCB), 2,5,4'-tricarboxymethyl (2,5,4'-TCB), phthalic acid (RA), isophthalic acid (IPA), benzoic acid (BA), trimellitate acid (TMA), para-tolarova acid (RTAS), 2,6-dicarboxylicacid (2,6-DCBC), 4,4'-dicarboxyethyl (4,4'-DCBZ), 4,4'-dicarbocyanine (4,4'-DCBP), 2,5,4'-tricarbocyanine (2,5,4'-the air bypass section). The following table 3 represents the preferred values for the levels of these contaminants in a HUNDRED, obtained in accordance with the variant of realization of the present invention.

In addition, it is preferable to a HUNDRED, obtained in accordance with the variant of realization of the present invention, could be characterized by low levels of colored compounds in comparison with a HUNDRED, obtained using conventional methods and apparatus, namely those that use a solvent that is sent for recycling. Thus, it is preferred to one HUNDRED, obtained in accordance with one implementation option is altoadige of the invention, could be characterized by percent transmittance in the region of 340 nanometers (nm), equal to at least about 25 percent, more preferably at least about 50 percent, and most preferably at least about 60%. In addition, it is preferable to a HUNDRED, obtained in accordance with one implementation of the present invention, could be characterized by percent transmittance in the region of 400 nanometers (nm), equal to at least about 88%, more preferably at least about 90 percent, and most preferably at least 92 percent.

Test with determination of the percentage of transmission is a method of measuring the amount of colored light-absorbing impurities present in the TRA or a HUNDRED. In accordance with the usage in this document the test refers to the measurements performed for a part of the solution resulting from dissolution of 2.00 grams of dry solid TPA or a HUNDRED in of 20.0 milliliters of dimethyl sulfoxide (DMSO) analytical or even higher purity. After this part of this solution is placed in palomacrataceous Hellma cuvette, PN 176.700, which is made of quartz, and which is characterized by optical 1.0 cm and a volume of 0.39 ml (Hellma USA, 80 skyline Drive, Play the view, New York 11803). To measure the transmittance at various wavelengths of light for this filled in a flow cell using a spectrophotometer Agilent 8453 Diode Array Spectrophotometer (Agilent Technologies, 395 the page mill road, Palo Alto, California 94303). After proper correction of optical density to account for the absorption of the background, including the used cuvette and solvent, but not limited to, the results for the percentage passing, describing the fraction of incident light that passes through the solution, the machine issues directly. Percentage transmittance for wavelengths of light in the region of 340 nanometers and 400 nanometers are particularly suitable for use in the differentiation of the contribution of net TRA from the contribution of many impurities, usually find it.

Preferred ranges for the levels of various aromatic impurities in the phase of the suspension (solid phase+liquid phase) reaction medium is presented below in table 4.

Data preferred compositions for suspensions represent a preferred embodiment of the composition of the liquid phase reaction medium while simultaneously matching the elimination of experimental difficulties related to the deposition of additional components of the liquid phase of the reaction medium is receiving components of the solid phase during the sampling of the reaction medium, the separation of a liquid phase and a solid phase, and offset conditions to the conditions of analysis.

In the phase of the suspension reaction medium and in a HUNDRED of the reaction medium is usually also present many other aromatic impurities in the General case when the variation of content to even lower levels and/or share content from one or more of the described aromatic compounds. Regulation of the levels described aromatic compounds during curing in the preferred ranges will ensure adherence to appropriate levels and other aromatic impurities. Data best formulations for phase suspension in the reaction medium and the solid of one HUNDRED, taken directly from the suspension, become possible as a result of operations when using variants of the invention described in this document for the partial oxidation of para-xylene to receive TRA.

The measurement of the concentration of the components of the low level content in the solvent, the solvent is sent to recycling, HUNDRED, suspension from the reaction medium and MOUTH carried out using methods of liquid chromatography. At the moment, will be described two interchangeable implementations.

The method, referred to herein as jhud-DMD includes liquid chrome is tography high pressure (ghvd) coupled with diode-array detector (DMD), that provides separation and obtaining quantitative characteristics for different molecular compounds in a given sample. The instrument used in this measurement represents the model 1100 HPLC equipped with a DMD device, supplied by Agilent Technologies (Palo Alto, California), although commercially available are also other suitable devices purchased from other suppliers. As it is known at the present level of technology, as the time of elution, and the detector response was calibrated using known compounds present in known amounts, with connections and number are relevant compounds and quantities present in the actual unknown specimens.

The method, referred to herein as jhud-MC includes liquid chromatography high pressure (ghvd) in combination with mass spectrometry (MS), which provides the separation, identification and obtaining quantitative characteristics for different molecular compounds in a given sample. The instruments used in this measurement, represent Alliance HPLC and ZQ MS supplied by Waters Corp. (Milford, Massachusetts), although commercially available are also other suitable devices purchased from other suppliers. As it is known on the modern level of the e equipment, as the time of elution, and the response of the mass spectrometer is calibrated using known compounds present in known amounts, with connections and number are relevant compounds and quantities present in the actual unknown specimens.

Another embodiment of the present invention relates to the partial oxidation of oxidizable aromatic compound with an appropriate balance between the suppression of harmful aromatic impurities, on the one hand, and obtaining carbon dioxide and carbon monoxide, are collectively called oxides of carbon (SoH). These oxides of carbon usually leave a reaction chamber in the exhaust gas, and they correspond caused by the destruction of the loss of solvent and oxidized compounds, including, ultimately, the preferred derivatives of oxidized compounds (for example, acetic acid, para-xylene and TRA). The inventors have found lower bounds for the formation of carbon oxides, below which seems high efficiency harmful aromatic impurities, described later, and a low total degree of conversion inevitably become too poor to be attractive from the point of view of the economy. From rettele also found upper bounds for oxides of carbon, above which the formation of carbon oxides continues to grow at low additional value provided by reducing the efficiency of formation of harmful aromatic impurities.

The inventors have discovered that the reduction of concentrations in the liquid phase reaction medium formed for oxidizable aromatic compound source material supplied and aromatic intermediates leads to a decrease in the velocity of formation of impurities during the partial oxidation of oxidizable aromatic compounds. Data impurities include conjugated aromatic rings and/or aromatic molecules with more than desirable, the number of carboxylic acid groups (for example, in the case of oxidation of para-xylene impurities include 2,6-dicarboxaldehyde, 2,6-dicarboxylate, trimellitic acid, 2,5,4'-tricarboxymethyl and 2,5,4'-benzophenone). Aromatic intermediate compounds include aromatic compounds originating from the source feed material formed oxidizable aromatic compound, and still retains nah gidrolabilna group (for example, in the case of oxidation of para-xylene aromatic intermediate compounds include para-Truelove aldehyde, terephthalic aldehyde, para-Truelove acid, 4-With Whom And, 4-hydroxymethylbenzene acid and alpha-bromo-para-Truelove acid). Formed oxidizable aromatic compound source supplied material and aromatic intermediate compounds maintaining nah gidrolabilna group, in case of their presence in the liquid phase reaction medium, apparently, lead to harmful impurities by the method similar to what was already described in this document for dissolved aromatic compounds that do not have non-aromatic hydrocarbonrich groups (e.g., isophthalic acid).

Confronted with this fact needs increased activity in the reaction to inhibit the formation of harmful aromatic impurities during the partial oxidation of oxidizable aromatic compounds, the inventors have found that undesirable concomitant result is increasing the efficiency of formation of oxides of carbon. It is important to realize that these oxides of carbon represent a yield loss in respect of the oxidizable compound and oxidant, and not only solvent. It is obvious that a significant, and sometimes the bulk of oxides of carbon in its origin has oxidizable compound and its derivatives, not solvent; and often per unit of carbon oxidized connection is worth more than rest ritel. In addition, it is important to realize that the desired product in the form of carboxylic acid (e.g., TPA) is also subject to excessive oxidation to obtain carbon oxides in case of its presence in the liquid phase reaction medium.

It is also important to realize that the present invention relates to reactions in the liquid phase reaction medium and the concentrations of reagents in it. This distinguishes it from some of the inventions of the prior art, which are directly related to the extraction of aromatic compounds maintaining nah gidrolabilna group, in the form of precipitated solid phase. Specifically, in the case of partial oxidation of para-xylene to obtain TRA certain inventions of the prior art refers to the amount of 4-CBA, precipitated in the solid phase of the HUNDRED. However, the relationship between the amounts of 4-CBA in the solid phase and 4-CBA in the liquid phase, the inventors of the present invention discovered the variability of the order of more than two to one when using the same technical conditions regarding temperature, pressure, catalysis, composition of solvent and reaction rate in a single pass per unit of time for para-xylene depending on whether the partial oxidation is carried out in a well-mixed autoclave or in a reaction medium with breaking article on the penalties against oxygen and para-xylene in accordance with the present invention. In addition, the inventors have observed that the ratio between the amounts of 4-CBA in the solid phase and 4-CBA in the liquid phase may also vary in more than two-to-one or in a well-mixed reaction medium or the reaction medium with the division into stages depending on the reaction rate in one pass per unit of time for para-xylene with other similar technical conditions regarding temperature, pressure, catalysis and composition of the solvent. In addition, the 4-CBA in the solid phase of a HUNDRED, apparently, does not contribute to the formation of harmful impurities, and 4-CBA in the solid phase is possible without problems and with a high yield of extract and subjected to oxidation to obtain TRA (for example, as a result of oxidative utilization for the suspension of a HUNDRED, as described herein); whereas the removal of harmful impurities is much more difficult and expensive in comparison with the removal of 4-CBA solid phase, and obtaining oxides of carbon corresponds to an irreversible loss of output. Thus, it is important to realize that this aspect of the present invention relates to liquid-phase compositions in the reaction medium.

The inventors have found that regardless of whether the source can be a solvent or oxidizable compound, when the degrees of conversion, ensure the sustained achievement of the attractiveness from the point of view of economy, obtaining carbon oxides is closely associated with the level of overall activity in the reaction despite the presence of wide variability for a specific combination of temperature, metals, Halogens, temperature, acidity of the reaction medium according to the measurement of pH, concentration of water used to achieve the level of overall activity in the reaction. The inventors have found that in the case of partial oxidation of xylene is useful to assess the level of overall activity in the reaction using the concentration in the liquid phase Truelove acids at mid-height of the reaction medium, in the area of the bottom of the reaction medium and in the area of the top of the reaction medium.

This forms an important simultaneous balance, allowing to minimize the formation of harmful impurities in the result of increased activity in the reaction and at the same time, to minimize the formation of oxides of carbon as a result of reduced activity in the reaction. That is, if the total oxides of carbon will be suppressed too small, then will be formed excessive levels of harmful impurities, and Vice versa.

In addition, the inventors have found that the solubility and the relative reactivity of the desired carboxylic acid (e.g., TPA) and the presence of other dissolved aromatic connect the developments not having a non-aromatic hydrocarbonrich groups, provide the introduction is very important fulcrum of the lever when it reaches this balance between oxides of carbon and harmful impurities. The desired product in the form of a carboxylic acid is usually dissolved in the liquid phase reaction medium even in the presence of it in solid form. For example, at temperatures in the preferred ranges TRA is soluble in the reaction medium containing acetic acid and water, at levels in the range of approximately one thousand hours/mn (wt.) to more than 1 mass%, with increasing temperature, the solubility increases. Despite the existence of differences in the speeds of reactions leading to the formation of various harmful impurities formed of oxidizable aromatic compound source material supplied (for example, para-xylene), of aromatic intermediates in the reaction (for example, para-Truelove acid)of the desired product in the form of aromatic carboxylic acids (e.g., TPA) and aromatic compounds that do not have non-aromatic hydrocarbonrich groups (e.g., isophthalic acid), the presence and reactivity of the latter two groups defines the area reduction effect in terms of additional suppression for pervided groups, formed oxidizable aromatic compound source material supplied and aromatic intermediates in the reaction. For example, if in the case of partial oxidation of para-xylene to obtain TRA amount of dissolved TRA will be 7000 h/mn (wt.) in the liquid phase reaction medium under specified conditions, the amount of dissolved benzoic acid will be 8000 hours/mn (wt.), the amount of dissolved terephthalic acid will be 6000 h/mn (wt.), and the amount of dissolved phthalic acid will be 2000 hours/mn (wt.), then the trend towards further reducing the total content of harmful compounds will begin to diminish as the activity in the reaction will increase, providing suppression of the concentration in the liquid phase to vapor-Truelove acid and 4-CBA to values smaller similar levels. That is, the presence and concentration in the liquid phase reaction medium aromatic compounds that do not have non-aromatic hydrocarbonrich groups, are exposed to very small changes in the result of increased activity in the reaction, and their presence serves to expand up the area reduction effect in the decrease in the concentration of intermediates in the reaction in order to suppress the formation of harmful impurities.

Thus, the in an embodiment of the present invention achieves the preferred ranges of carbon oxides, limited with the lower edge of the low activity in the reaction and excess formation of harmful impurities, and with the top edge of redundant degrees of loss of carbon, but at levels lower in comparison with the previously disclosed and described as suitable for commercial use. In line with this, the formation of carbon oxides is preferably adjust as follows. The ratio of moles of the aggregate of carbon oxides and numbers of moles of supplied oxidizable aromatic compound preferably has a value of greater than approximately 0,02:1, more preferably greater than roughly 0.04:1, even more preferably greater than about 0.05:1, and most preferably greater than 0.06 to:1. At the same time, the ratio of moles of the aggregate of carbon oxides and numbers of moles of supplied oxidizable aromatic compounds is preferably less than about 0.24 to:1, more preferably less than about 0,22:1, even more preferably less than about 0,19:1, and most preferably less than about 0.15:1. The ratio of moles of the obtained carbon dioxide and the quantity of moles of supplied oxidizable aromatic compounds Ave is doctitle has value greater than about 0.01:1, more preferably greater than about 0.03:1, even more preferably greater than roughly 0.04:1, and most preferably greater than 0.05:1. At the same time, the ratio of moles of the obtained carbon dioxide and the quantity of moles of supplied oxidizable aromatic compounds is preferably less than approximately 0,21:1, more preferably less than about 0,19:1, even more preferably less than about 0,16:1, and most preferably less than 0,11:1. The ratio of moles of the obtained carbon monoxide and numbers of moles of supplied oxidizable aromatic compound preferably has a value of greater than approximately from 0.005:1, more preferably greater than about 0,010:1, even more preferably greater than approximately 0,015:1, and most preferably greater than 0,020:1. At the same time, the ratio of moles of the obtained carbon monoxide and numbers of moles of supplied oxidizable aromatic compounds is preferably less than approximately 0,09:1, more preferably less than about 0.07 to:1, even more preferably less than about 05:1, and most preferably less than 0,04:1.

The level of carbon dioxide in dry exhaust gas from the oxidation reactor is preferably a value greater than approximately 0.10 to molar percent, more preferably greater than about 0.20, the molar percent, more preferably greater than approximately 0.25 mole percent, and most preferably greater than 0,30 molar percent. At the same time, the level of carbon dioxide in dry exhaust gas from the oxidation reactor is preferably less than about 1.5 mole percent, more preferably less than about 1.2 mole percent, even more preferably less than approximately a 0.9 molar percent, and most preferably less than 0.8 mole percent. The content of carbon monoxide in dry exhaust gas from the oxidation reactor is preferably an amount greater than about 0.05 mole percent, more preferably greater than approximately 0,10 mol%, even more preferably greater than about 0.15, and most preferably greater than 0,18 molar percent. At the same time, the content of carbon monoxide in dry exhaust gas from the oxidation reactor PR is doctitle has value less than approximately 0,60 molar percent, more preferably less than about 0.50 mole percent, even more preferably less than around 0.35 mole percent, and most preferably less than 0,28 mol percent.

The inventors have found that an important factor in reducing the effectiveness of the oxides of carbon to these preferred ranges is improved purity sent to recycling the filtrate and the original feed material, formed oxidizable compound, by reducing the concentration of aromatic compounds that do not have non-aromatic hydrocarbonrich groups, in accordance with the description of the present invention, it simultaneously reduces the efficiency of formation of carbon oxides and contaminants. Another factor is the improved distribution of para-xylene and oxidant in the reaction vessel in accordance with the description of the present invention. Other factors that make possible the achievement of the above preferred levels of oxides of carbon, are functioning in the presence of gradients in the reaction medium described herein in relation to pressure in relation to temperature, in relation to the concentration of oxidizable compound in the fluid is phase and the oxidant in the gas phase. Other factors that make possible the achievement of the above preferred levels of oxides of carbon, are functioning within the framework of the description of this document in respect of options, preferred for the reaction rate in one pass per unit of time, pressure, temperature, solvent composition, catalyst composition and geometry of the mechanics of the reaction vessel.

An important advantage arising from the operation within the preferred ranges, the formation of oxides of carbon, is that can be reduced using molecular oxygen, although not to the stoichiometric values. Despite a good break on stage against oxidant and oxidizable compounds in accordance with the present invention an excess of oxygen must be maintained at greater than stoichiometric value calculated for only one of the original feed material, formed by oxidative connection that makes possible certain losses in connection with the oxides of carbon and ensures the presence of excess molecular oxygen to regulate the formation of harmful impurities. Specifically for the case in which the source of the supplied material, formed by the oxidizable compound is a xylene, the ratio of the giving in the original feed material between the mass of molecular oxygen and weight of xylene is preferably an amount greater than approximately 0,91:1,00, more preferably greater than about 0.95:1.00 and most preferably greater than 0,99:1,00. At the same time, the ratio in the original feed material between the mass of molecular oxygen and weight of xylene is preferably less than approximately 1,20:to 1.00, more preferably less than approximately 1,12:1.00 and most preferably less than 1,06:1,00. Specifically for the original feed material, formed by xylene, sredneuralskoj the content of molecular oxygen in dry flue gas from the oxidation reactor is preferably an amount greater than about 0.1 mole percent, more preferably greater than about 1 molar percent, and most preferably greater than 1.5 mole percent. At the same time sredneuralskoj the content of molecular oxygen in dry flue gas from the oxidation reactor is preferably less than about 6 mole percent, more preferably less than about 4 mole percent, and most preferably less than 3 mole percent.

Another important advantage arising from the operation within the preferred ranges oxide ug is erode, is that the oxides of carbon and other less valuable forms into a smaller number of aromatic compounds. This advantage is appreciate when using the sum of moles of all aromatic compounds, leaving the reaction medium, divided by the sum of moles of all aromatic compounds coming in the reaction medium, during the continuous period of time duration preferably in one hour, more preferably within one day, and most preferably 30 consecutive days. This ratio is hereafter in this document referred to as "mole fractions of survival for aromatic compounds during passage through the reaction medium and is expressed through a numerical percentage. If all incoming aromatic compounds will leave the reaction medium in the form of aromatic compounds, at least mainly in the oxidized forms coming aromatic compounds, then the molar proportion of survival will have its maximum value of 100 percent. If exactly 1 out of every 100 applicants aromatic molecules passing through the reaction medium will turn into oxides of carbon and/or other non-aromatic molecules (e.g., acetic acid), then the molar proportion of survival will be equal to 99 percent. Speaking concrete is for the case in which the main source of supplied material formed oxidizable aromatic compound is xylene, molar proportion of survival for aromatic compounds during passage through the reaction medium is preferably an amount greater than about 98 percent, more preferably greater than about 98.5%, and most preferably less than 99,0%. At the same time and in order to ensure the availability of sufficient total activity in the reaction molar proportion of survival for aromatic compounds during passage through the reaction medium is preferably less than about 99.9%, more preferably less than about 99.8 percent, and most preferably less than 99.7 percent, if the primary source of supplied material formed oxidizable aromatic compound is xylene.

Another aspect of the present invention comprises the production of methyl acetate in the reaction medium containing acetic acid and one or more oxidizable aromatic compounds. This acetate is a relatively volatile compound in comparison with water and acetic acid, and thus, it tends to follow the flue gas, if only for its extraction and/or des is the construction before the release of exhaust gas back into the environment will not be used additional operation in the cooling or the other installed. Thus, obtaining acetate carried out in the presence of operating costs and capital costs. It may well be that the acetate will be obtained by first combining a methyl radical, may be formed in the decomposition of acetic acid with oxygen from getting methylhydroperoxide, the subsequent decomposition of obtaining methanol and, finally, as a result of the reaction between the obtained methanol and residual acetic acid with getting acetate. Regardless of the way a chemical reaction, the inventors have found that whenever obtaining acetate occurs at very low speed, the efficiency of formation of carbon oxides is also extremely small, and the efficiency of formation of harmful aromatic impurities will be excessively large. If getting acetate will occur at excessively high speed, then also will be unnecessarily high and the efficiency of formation of oxides of carbon, leading to losses of output in relation to the solvent, oxidizable compound and oxidant. In the case of the preferred variants of the implementation described herein, the ratio to receive between the numbers of moles of the resulting acetate and quantities m the LEU supplied oxidizable aromatic compound is preferably an amount greater than approximately from 0.005:1, more preferably greater than about 0,010:1, and most preferably greater than 0,020:1. At the same time the ratio to receive between the numbers of moles of the resulting acetate and the numbers of moles of supplied oxidizable aromatic compounds is preferably less than approximately 0,09:1, more preferably less than about 0.07 to:1, even more preferably less than about 0.05:1, and most preferably less than 0,04:1.

This invention can be further illustrated using the following examples of its preferred options for implementation, although it should be understood that these examples are included merely for purposes of illustration and is not intended to limit the scope of the invention unless otherwise specifically indicated.

EXAMPLE 1

This is a working example of a commercial oxidation of para-xylene in a bubbling reactor column. This example illustrates, for example, that when, in accordance with aspects of the present invention uses appropriate geometric and technological conditions for concentrations of para-xylene are large vertical gradients.

In this example, the used capacity commercial bubble R. the actor column oxidation, having almost vertical, essentially cylindrical body, characterized by an inner diameter of approximately 2,44 meters. The height of the tank bubble column reactor oxidation was approximately 32 meters from the bottom line of the beginning of the bend (TL) to the upper TL. In the areas of the top and bottom of a cylinder capacity equipped with elliptical bottoms configuration approximately 2:1. Work level was about 25 meters of the reaction medium above the lower TL. Consumption when applying para-xylene technical purity in essence was fixed and equal to approximately 81 kilogram per minute, while the flow in a reaction chamber maintained through a round hole, available in the wall of the cylindrical section at the level of height, located approximately 4.35 meters above the lower TL. The internal diameter of the said hole in the wall was approximately 0,076 meters. The solvent of the filtrate was applied essentially at steady flow rate approximately equal to 777 kilograms per minute. Netherway share of the solvent of the filtrate, as assessed by the channel dimensions and pressure drops component of approximately 20 pounds per minute was applied as a wash liquid in the bubbler oxidant. The rest of the solvent of the filtrate, approximately 757 pounds in a mine is, filed thoroughly mixed with para-xylene technical purity. The combined flow of liquid source material supplied from the solvent of the filtrate and para-xylene technical purity, therefore, was approximately 838 pounds per minute, which for input flow through the said opening in the wall led to obtaining the flow rate per unit cross section of flow of approximately 3 meters per second. The solvent of the filtrate was transferred from system of administration on recycling in the installation and consisted of more than about 97 weight percent of acetic acid and water. The concentration of the catalyst components in the solvent of the filtrate was such that the composition of the liquid phase reaction medium corresponded to approximately 1777 h/mn (wt.) cobalt, about 1518 h/mn (wt.) bromine and approximately 107 h/m (wt.) manganese. A separate stream of solvent medium irrigation was applied in the form of droplets in the separation zone gas above the working level of the reaction medium essentially at steady flow rate approximately equal to 572 kilograms per minute. This solvent medium irrigation consisted of more than about 99 weight percent of acetic acid and water; and solvent medium irrigation came from a separate system of administration on recycling in the plant, for which the characteristic is Erno the absence of significant levels of catalyst components. The combined level of water content in the original feed material, formed by the solvent of the filtrate, and the original feed material, formed by the solvent environment, irrigation, was such that the water concentration in the liquid phase reaction medium was about to 6.0 mass%. Oxidant was compressed air supplied essentially at steady flow rate of approximately 384 kilograms per minute, through a bubbler oxidant such as that illustrated in figures 2-5. This bubbler oxidant included coupled with the angle of the channel for the flow, which represented approximately equilateral octagon, having a transverse element connecting one side with the opposite side and passing through the vertical axis of symmetry of the reaction vessel. Coupled with the angle of the channel currents were made from piping components, Schedule 10S with nominal 12 inches. The width of the octagon from the center of gravity of one side of the channel to flow to the center of gravity of the opposite side was approximately 1.83 meters. The octagon is located approximately horizontally, and a middle level height for an octagonal channel was located approximately 0.11 meters above the lower TL of the reaction vessel. Bubbler oxidant had a 75 round is twisty, which was characterized by a diameter approximately equal to 0.025 meters. The holes are approximately evenly spaced around the octagon and the transverse element near the top of the above 12-inch pipeline. Near the bottom of only one side of the octagonal channel had one round hole, characterized by a diameter approximately equal to 0,012 meters. Working pressure for gas the top of the reaction vessel was stationary value of approximately 0,52 MPa overpressure. A reaction chamber functioned essentially adiabatic mode so that the heat of reaction increased the temperature of the incoming source of supply of materials and evaporated significant portion of the solvent. Measured close to the median level height for the reaction environment operating temperature of approximately 160°C. the Exhaust stream of a suspension containing crude crude terephthalic acid (CTA)were removed from the area in the vicinity of the bottom of the lower elliptical bottom of the reaction vessel, essentially at steady flow. The flow rate for the exhaust flow of the suspension was approximately 408 kilograms per minute.

Samples of the suspension from the reaction medium were obtained at three levels along the height of the reaction the flask so, as described later. When determining the concentration of various substances in different positions in the reaction medium, it was necessary to take into account the stochastic nature of the system, selecting the number of samples sufficient to determine srednerazmernogo values with sufficient resolution.

One set of five samples was received from the channel for the exhaust flow of the suspension near the bottom of the lower elliptical bottom of the reaction vessel. Another set of five specimens were obtained from holes in the wall at the height, located approximately 12.4 meters above the lower TL of the reaction vessel. The third set of five samples were obtained from holes in the wall at the height, located approximately 17.2 meters above the lower TL of the reaction vessel.

All samples of the suspensions were subjected to analysis by the method of calibrated gas chromatography (GC), by setting the content of para-xylene and para-Truelove aldehyde in the liquid phase. The following table 5 shows the average for the five results in the column was obtained at three different levels in height. The results are presented as mass parts of analyte per million mass parts (h/mn (wt.)) the liquid phase.

TABLE 5
The position of the selected samplePara-xylene (h/mn (wt.))Pair-Truelove aldehyde (h/mn (wt.))
The side wall is approximately 17.2 meters21140
The side wall is approximately 12,4 m63317
Floor drain from the bottom of the bottom455960

These results demonstrate the presence of large gradients vertically in relation to local concentrations of para-xylene and para-Truelove aldehyde. For example, the gradient of concentration of para-xylene, the observed data in table 5, was a more than 20:1 (455:21). These results demonstrate that inherent in the system of mixing the fluid in the bubble column for the source of the feed material, formed by the coming of para-xylene, was significantly slower in comparison with the inherent system speed reactions. To a lesser extent, vertical gradients were observed also with respect to the concentrations of other related aromatic reaction-FPIC the service of the substances in the reaction medium (for example, pair-Truelove acid and 4-carboxybenzene).

As demonstrated in the following examples, detailed design models demonstrate that the actual range of the concentration of para-xylene in the liquid phase reaction medium of this example was considerably higher than 100:1. Even without the strict computational models of experts in the relevant field should understand that the actual maximum concentration of para-xylene was observed near the place where through the vessel wall bubble column reactor in the capacity of the injected source supplied material formed para-xylene. This level height corresponding to the maximum concentration of para-xylene, is approximately 4.35 meters above the lower TL in the interval between the sampling points from the position at the level of approximately 12,4 m and from the bottom drain. Similarly, the actual minimum concentration of para-xylene, apparently, was in the area of the top of the reaction medium, corresponding to approximately 25 meters, or in the area, located a short distance from it, which is much higher than the position with the maximum height from which were selected the above samples.

The concentration of para-xylene and other oxidizable compounds can be measured and for other positions in the reaction cf is de when using suitable mechanical devices for sampling from any point in the reaction medium vertically or horizontally. Concentrations in positions that did not make physical sampling and chemical analysis of samples, it is not necessarily possible to calculate with reasonable accuracy using computational models, characterized by complexity, sufficient to describe extremely complex schemes of flow of the fluid, the kinetics of chemical reactions, energy balance, equilibrium steam-liquid-solid phases and velocities interfacial exchange.

EXAMPLES 2-5

Examples 2-5 are the estimated models bubbling reactor columns, or identical to the reactor of example 1, or in General like him in the presence of these improvements. Modelling in computational fluid dynamics (CFD), which upon receipt of examples 2-5 were carried out in accordance with the method of modeling described patent application U.S. serial number 60/594774, entitled “Modeling of Liquid-Phase Oxidation, which is being reviewed concurrently with this patent application and the description of which in its entirety clearly is incorporated herein by reference.

In examples 2-5 CFD modelling carried out using the software CFX release 5.7 (ANSYS, Inc., 275 Technology Drive, Canonsburg, PA 15317). Each of examples 2-5 includes more than approximately 100,000 discrete space is s computational cells. Time steps suitable for use in examples 2-5, are values that are less than 0.1 seconds. When optimizing the parameters of the CFD model for a more accurate approximation to describe the average value of the retention of bubbles measured by measuring the differential pressure, the vertical profile of the magnitude of the retention of bubbles measured using gamma scanning, and horizontal profiles of the magnitude of the retention of bubbles measured using the scanning method of computed tomography (CT), suitable for use turned out to be a variety of sizes of bubbles with diameters in the range of approximately from 0.005 to about 0.20 per meter. In order to select the appropriate size and population of bubbles in the CFD models from examples 2-5, the actual operational data for the installation received when using a slurry bubble columns with internal diameters of the cylinders of approximately 2,44 meters and approximately 3,05 meters, and functioning when using the reaction medium, characterized by appropriate composition and process conditions which are close to those that are described next. Reference data for the total amount of retention of bubbles received when using the pressure difference, measured between the region in the vicinity of the first capacitance, until the field of exhaust gas of the top of the reactor. Reference data for the vertical profile of the magnitude of the retention of bubbles was obtained when using a gamma-emitting radioactive source and method of detecting movement upwards on the outer side of the reaction vessel with steps in the range from about 0.05 m to about 0.3 meters. Reference data for the horizontal profiles of the magnitude of the retention of bubbles received when using CT scans to be performed for a grid of nine by nine in the horizontal plane of the working bubble columns using gamma-emitting radioactive source and method of detection. That is, the source was positioned at a specified height at nine different positions, spaced approximately evenly along the perimeter of the bubble column. For each position of the gamma value of the gamma radiation passing through a reaction chamber and a reaction medium, were detected in nine different positions, spaced approximately evenly along the perimeter of the bubble column. Then these discrete data used various mathematical models and obtained estimates of changes in the value retention of bubbles in the reaction medium for the above-mentioned level height. Many horizontal scan is of Romani ARTICLE was received for two different days, on two different levels in height and at two different costs when submitting para-xylene, compressed air and the like.

Model chemical reactions that consume the para-xylene in the environment, was set up in accordance with the profiles of the reagent for para-xylene, found in example 1, together with other data like temperature, pressure, intensity of reactions, catalysis, concentration of water, and the like, obtained in tests of both industrial and semi-industrial scale. As an illustrative approximation, the time constant of pseudobersama order for the death of para-xylene reactive token equal to about 0.2 seconds to reverse at about 160°C and approximately average conditions for the reaction medium used in examples 2-4.

It is important to note that models for CFD flow fields obtained in examples 2-4, lead to large-scale fluctuations in relation to clusters of bubbles and fluid pulsations, which in General case is consistent with the observed low-frequency wave-like movements in the vessel operating bubble column reactor.

EXAMPLE 2

This example develops the calculations related to the mechanical configuration of example 1, and sets the basis for comparison with examples 3 and 4. In this example, the tavern is ical configuration of the bubble column reactor identical to the one what occurred in example 1, characterised by the presence of round inlet with a diameter 0,076 m in the wall of the reaction vessel, designed to flow the original feed material containing para-xylene and the solvent of the filtrate. Consumption when applying para-xylene is approximately 1.84 kilograms per second, exceeding that occurred in example 1. Consumption when applying solvent of the filtrate applied thoroughly mixed with para-xylene is about to 18.4 pounds per second. Thus, the flow rate per unit cross section of flow for the combined stream of para-xylene plus solvent of the filtrate flowing through the hole in the wall, approximately 4 meters per second. Consumption when applying solvent medium irrigation in free space to separate the gas above the liquid level is 12.8 pounds per second. Flow rate at compressed air through the bubbler oxidizer is approximately 9 kilograms per second. The level of solids in the suspension of the reaction medium is approximately 31 mass%. A suspension of the product is taken from the center of the bottom of the bottom of the reaction vessel using essentially stationary flow, providing holding approximately steady state level of approximately 25 what the parameters of the reaction medium. The average retention of gas on a middle level height for the reaction medium is approximately 55 percent when calculating for sredneformatnykh and srednerazmernyh values, where the length of the averaging time is at least approximately 100 seconds of time in the CFD model. The pressure in the space above the liquid level of the reaction medium is about 0.50 MPa overpressure. The temperature is approximately 160°C according to measurements close to the median level height for the reaction medium. The levels of water content and cobalt, bromine and manganese in the liquid part of the reaction medium are essentially the same as in example 1.

EXAMPLE 3

This example develops the calculations related to the improvement of the degree of dispersion for the original feed material, formed para-xylene, by increasing the flow rate per unit cross section of flow for the liquid source feed material containing para-xylene, at the point of its introduction into the reaction environment in accordance with one aspect of the present invention. In this example, the mechanical configuration of the bubble column reactor identical to the one that occurred in example 2, except that the round hole in the wall through which the injected liquid is asny source the feed material, containing para-xylene, are reduced to the diameter of 0.025 meters. Consumption when applying para-xylene and other process conditions are the same as in example 2, except that the flow rate per unit cross-section for flow combined liquid source feed material formed para-xylene plus solvent of the filtrate and coming through the hole in the wall, which in this case is approximately 36 meters per second.

The calculations in the model for CFD srednerazmernyh shares of the reaction medium with the concentration of para-xylene reactive token in the liquid phase, exceeding various threshold values presented in the following table 6. The volume of the reaction medium, with a very high concentration of para-xylene reactive token in the liquid phase decreases due to the operation at high speeds at the inlet for flow of liquid source feed material containing para-xylene, in accordance with the present invention. Reduced areas of high concentration of para-xylene, it is important to limit the passage of undesirable reactions mates, as determined by increased concentrations of many soluble aromatic substances, and due to the fact that such concentration is avodat to locally high expenditure of dissolved molecular oxygen and, thus, lead to a local suppression of the steady-state concentrations of dissolved molecular oxygen.

TABLE 6
Example 2Example 3Example 4
The diameter of the hole in the wall (m)0,0760,025Dispenser
The flow rate per unit cross section of flow for the incoming para-xylene + filtrate (m/s)436The variation of >15
The percentage of the reaction medium with the concentration of para-xylene,
More than 1000 h/mn (wt.) (%)
In excess of 2500 hours/mn (wt.) (%)
In excess of 10000 hours/mn (wt.) (%)
Exceeding 25000 h/mn (wt.) (%)
3,64
0,640
0,049
0,009
3,28
0,378
0,022
0,002
to 3.73
0,130
0,005
0,001
The volume of the reaction medium with the concentration of para-xylene,
More than 1000 h/mn (wt.) (liter)425038404360
In excess of 2500 hours/mn (wt.) (liter)749444152
In excess of 10000 hours/mn (wt.) (liter)57266
Exceeding 25000 h/mn (wt.) (liter)1021

EXAMPLE 4

This example develops the calculations for improved mechanical device intended for introduction into the bubbling reactor column oxidant and para-xylene. This example is implemented in the same bubbling reactor column, as used in examples 1-3. However, the reactor modify in relation to the way in which the reaction medium is injected as the oxidant, and para-xylene. During the discussion of the example 4, the priority should be given to a modified apparatus intended for the introduction of para-xylene in the reaction medium, which can reduce the number of areas with high concentrations of para-xylene. Secondly, attention should be paid to modi is annoy equipment, intended for introduction into the reaction medium oxidant, which can reduce the number of zones that are not aerated. In this case it is assumed that the two versions are completely independent in its results, this is just the staged representation.

The amount of reaction medium, with a very high concentration of para-xylene reactive token in the liquid phase, in example 4 is reduced through the use of the distribution system of liquid source feed material, in the General case shown in figures 9-11. In case the distribution system of liquid source material supplied has four channels for the flow in a convenient case, standing approximately vertically. Each of these four channels for the flow is located at a distance of approximately 0.75 m from the vertical axis of symmetry of the bubble column. The data of four channels for the flow in the case is made from piping components, Schedule 10S with a nominal value of 1.5 inches. The bottom edge of each rack in this example, a case is a section of a converging cone inner angle measured between the opposite sides of the cone, which is in a convenient case is approximately 24 degrees; however, for circuit n is held farther along the stream edge of the channel to flow suitable are also other forms (for example, a conical plug having a different internal corner cap in the form of a flat plate, plug cap pipe, wedge-shaped cap and the like). Each of these four channels for the flow in the aggregate, has nine round holes, each of which has a diameter of approximately 0,0063 meters. The lowest of the nine holes in each channel is located in the area of the bottom of the lower conical section. Each channel the bottom of this hole is located approximately 0.4 meters above the lower TL of the reaction vessel. When measuring in any case from the lower edge of the truncated conical bottom section of the next three holes in each channel are above approximately 0.3 meters, the next three holes are located above approximately 1.6 meters, and the top two holes are located above approximately 2.7 meters. Thus, the vertical distance from the bottom hole to the top hole in each channel is approximately 2.7 meters or approximately 1,1D. Linear distance (not vertically), corresponding to the largest spacing of the holes from the bottom hole of one of the vertical channel to the upper holes of the vertical channel located diagonally opposite, is the app is siteline 3,44 meters or approximately 1,4D. For each level openings have approximately evenly spaced around the circumference of each channel for the flow. The flow channel for the original feed material, formed oxidizable compound and a solvent, in the region of the top four approximately vertical channels in a convenient case is held approximately horizontally at the level of height, located approximately 3.60 meters above the lower TL of the reaction vessel. The feed channel in a convenient case is made from piping components, Schedule 10S with nominal 3 inches. In order to counteract both static and dynamic forces that occur during both normal and abnormal conditions, there are adequate mechanical cross-struts in this rally site and mechanical spacers between the data collecting node and bubbler oxidant and reaction capacity.

Possible are many other designs of this system of distribution of the liquid source feed material, although in this example, their calculations and missing. For example, the dimensions of the channels for the flow of fluid can be larger or smaller values, or may have a cross section other than roughly circular, or may have a number of channels other than four. For example, in each of the four p is essentially vertical flow channels could be independently through the channels for the flow, individually passing through the pressure wall of the reaction vessel. For example, the connecting element, which feeds coming in para-xylene and formed by the solvent of the original feed material, could lead to the area close to the median level in height, or in the area close to the level height for the bottom, or in the area at any level in height or more levels in height from approximately vertical channels. For example, the input channels would be approximately vertical when the distribution of holes on approximately horizontal channels, or both directions of flow could be oriented at an angle or to be non-linear or non-orthogonal. For example, the holes could have different radial, azimuthal and vertical location relative to the reaction medium. For example, you may use more or fewer holes and/or holes of different shapes and/or holes with mixed sizes and/or mixed forms. For example, instead of venting holes could be used exhaust nozzle. For example, out-of-channel flow in the vicinity of the outlet and in the path of the fluid at the exit of the reaction medium can be positioned one or n is how many devices to discard the current.

Depending on the nature and level of solids, if any, in the merged source feed material formed para-xylene and the solvent or reaction medium and, depending on the methods of starting, stopping, and other operational procedures used to carry out the actual operations required may be blowing the solid phase from the internal space of the distribution system of liquid source feed material. Hole to blow in an appropriate case, may be larger than openings of uniform size, as demonstrated in this example, although in this example the calculations and missing. The hole on the bottom edge of each of the four approximately vertical racks is particularly suitable for blowing the solid phase, although it is not the only possible way. More complex mechanical devices, such as prefabricated nodes valves, check valves, overflow valves, valves with servo motor and the like, can be used either to prevent the ingress of solid phase, or to release the accumulated solid phase from the distribution system of liquid source material supplied.

At this point attention should be paid n the bubbler oxidant, which in General is what is demonstrated in figures 12-15. The annular element bubbler oxidant in a convenient case includes connected at an angle to the channel for the flow, which is convenient and close the case is an equilateral octagon without transverse element. Coupled with the angle of the channel to flow in a convenient case is made from piping components, Schedule 10S with a nominal value of 10 inches. The width of the octagon from the center of gravity of one side of the channel to flow to the center of gravity of the opposite side of approximately of 1.12 meters. The octagonal cross-section in a handy case is located approximately horizontally, and a middle level height for an octagonal cross-section is approximately 0.24 m below the lower TL of the reaction vessel. This option clearly differs from the ring element bubbler oxidant from examples 1-3, the levels at the height for which centered above the lower TL of the reaction vessel. The octagonal part of the channel perforined using approximately 64 round holes, each of which has a diameter approximately equal to 0,030 meters, and which are located on the channel approximately evenly. About half of the holes have a channel in positions that ori is mounted at an angle, approximately equal to 45 degrees measured from the horizontal down, taking measurements from each hole to the nearest center of gravity of the cross section of the channel for the flow. About half of the holes have a channel in positions that are close to the bottom of the channel for the flow (i.e. at an angle approximately equal to 90 degrees and measured from the horizontal down, taking measurements from each hole to the nearest center of gravity of the cross section of the channel for the flow). Inventors again should be a comment, such comments in respect of the distributor at the inlet for the liquid phase, due to the fact that the bubbler oxidant is possible and a number of other concrete structures that fall in the scope of several aspects of the present invention. For example, through the pressure wall can be more or less than two feed channel. For example, the input channels of the bubbler oxidant can be constructed without the inclusion of the annular element. For example, there may be more than one ring-shaped element, and any ring element may have other than 8 the number of sides or may have an unbalanced hand. For example, the design may be preferred pressure drop or site is titanium quality aeration, or preferred character, to prevent fouling, while using other number or size or sizes or locations of the holes or points of release for the channel. For example, the design may use other diameters of the channels in the preferred ranges. For example, the design can provide character to prevent fouling due to the use of washing liquid.

In this example, the reaction medium is taken essentially at steady flow from the side of the reaction vessel at the level of the height corresponding to approximately 14 meters, through a round hole in the wall, which is characterized by an inner diameter approximately equal to 0,076 meters. Selected reaction medium is divided into a suspension of the product containing crude crude terephthalic acid, and the exhaust gas resulting from the use of external deaeration capacity, which is fully described in example 6. The separated flue gas from an external deaeration capacity channel is transported to a junction with the main stream of the exhaust gas leaving the top of the reaction vessel.

Methods for CFD modeling of this example are essentially the same as in examples 2 and 3, if data are available except for the clusters. For advanced equipment that enables the distribution of incoming oxidant distribution of incoming oxidizable compounds and removal of suspension of the product from the side wall of the reaction vessel of about 14 meters above the lower TL, spatial grid partitioning modify properly known state of the art.

In order to evaluate the results of the CFD model with respect to the distribution of para-xylene reactive token, use the same methods as in examples 2 and 3. Namely, define srednerazmernye fraction of the reaction medium with the concentration of para-xylene reactive token in the liquid phase, exceeding various threshold values. To facilitate comparisons between the results of this example are presented in the above table 6. These results demonstrate that improved the distribution of para-xylene reactive token in this example, actually leads to a slight increase in the number of reaction medium, showing the excess of 1,000 hours/mn (wt.), but the levels corresponding to more harmful to a threshold of 2500 h/mn (wt.), 10000 h/mn (wt.) and 25000 h/mn (wt.), reduced. Obtaining these improvements is provided, for example, due to the increased speeds on the course for the source of the feed material together with improved vertical, radial and azimuthal location and spacing positions of the introduction of para-xylene in the reaction medium.

If we now turn to the quality of the aeration of the total volume of the reaction medium, it is possible to say that for estimation of unsatisfactory aerated volume in the reaction medium of examples 2-4 use the method of separation of 2000 horizontal lobes with equal subrange. Starting from the lower part of the reaction medium, namely from the bottom of the lower elliptical bottoms in this example, the reaction medium is divided into 2000 equal pogoryelov using theoretical horizontal planes. During each of the time intervals in the CFD model to determine the number of suspensions and the number of gas within each of these 2000 equal pogoryelov, which is used to calculate the average retention of gas in it. In order to take into account the stochastic nature of the process and its model CFD, the end result for the CFD model is subjected to temporal averaging over the time model with a duration of at least about 100 seconds and get srednerazmernye value retention of gas in each of 2000 equal pogoryelov.

Once for each of the 2000 equal pogoryelov will determine srednekraevoy the amount of gas retention, these values compare with ogbimi values, described in this document. For each threshold values take into account the aggregate amount does not correspond to the norm of pogoryelov and pogoryelov where there is no excess of specified thresholds. The following table 7 shows the number of horizontal lobes of the reaction medium from 2000 horizontal lobes with equal volume, for which Sredneuralskaya value retention of gas is less than 10 volume percent, less than 20 volume percent, and less than 30 volume percent, as for example 2 and example 4. Example 4 demonstrates a significant improvement in comparison with example 2.

TABLE 7
Example 2Example 4
Level height for the center of gravity of the ring element bubbler oxidant, counting from the bottom TL capacity (ft)+ 0,11- 0,24
The number of horizontal lobes of the reaction medium from 2000 horizontal fractions with an equal volume where Sredneuralskaya the value of the holding strip has value
Less than 10 volume percent7No
Less than 20 volume percent21No
Less than 30 volume percent41No

When comparing calculation examples 2 and 4 can also be noted that the source of the supplied material formed para-xylene, from example 4 release in the reaction medium below and closer to the stream of incoming oxidant in comparison with example 2.

EXAMPLES 5 and 6

Examples 5 and 6 represent working examples for commercial bubble column reactor oxidation, demonstrating the importance of minimizing the number of areas of poor aeration, improve how the introduction of the original feed material, formed para-xylene technical purity, ensuring the achievement of a greater degree vertical, azimuthal and radial dispersion, and lowering the point of introduction of the original feed material, formed para-xylene technical purity for its approximation to the maximum availability of molecular oxygen, with the availa able scientific C with the description of the present invention. In addition, these examples demonstrate advantages in terms of output, due to the presence of the outlet openings for the suspension of high level location.

During the partial oxidation of para-xylene is present in many different impurity compounds, usually resulting from conjugation of the aromatic rings. One of them is 4,4'-dicarbonitrile. This connection demonstrates a much higher absorption of light in comparison with terephthalic acid, and it greatly reduces the optical transmission of the target product. In addition, 4,4'-dicarbonitrile is a mixture, suitable for use in the monitoring of the quality of continuous oxidation, since it is selectively secreted into the solid phase reaction medium; therefore, the flow of solvent sent to recycling, industrial tanks bubbling reactor columns described in examples 5 and 6, there is normally very little 4,4'-decarboxylase. In examples 5 and 6, the concentration of 4,4'-decarboxylase was measured using an analytical method that uses ghud-MS calibration obtained using a suitable reference mixture containing the solvent and a known quantity of some of the analyzed substances in particular the inclusion of a known quantity of 4,4'-dicar is oxicillin. Analytical method ghud-MS is described in the above section "Detailed description".

EXAMPLE 5

Bubble column reactor used in this example has essentially the same mechanical configuration as the reactor of examples 1 and 2. The reactor is characterized by technological conditions, comparable with that in example 6, and it represents the basis for settlement. Work level was about 25 meters of the reaction medium. Steam-xylene technical purity was performed essentially stationary at a flow rate of approximately 81 kilogram per minute. The solvent of the filtrate was applied essentially at steady flow rate of approximately 793 kilograms per minute. Netherway share this material, according to the estimate of the size of the channel and the pressure drops component of approximately 20 pounds per minute was applied as a wash liquid in the bubbler oxidant. The rest of the solvent of the filtrate, approximately 773 kg per minute was applied thoroughly mixed with para-xylene technical purity. The combined liquid stream formed by the solvent of the filtrate and para-xylene technical purity, therefore, was approximately 854 kg per minute. The solvent of the filtrate is transported is of the system of administration on recycling in the installation, and it contained more than about 97 weight percent of acetic acid and water. The concentration of the catalyst components in the solvent of the filtrate was such that the composition of the liquid phase reaction medium corresponded to approximately 2158 h/mn (wt.) cobalt, about 1911 h/mn (wt.) bromine and approximately 118 hours/mn (wt.) manganese. A separate stream of solvent medium irrigation was applied in the form of droplets in the separation zone gas above the working level of the reaction medium essentially at steady flow rate approximately equal to 546 kilograms per minute. This solvent medium irrigation consisted of more than about 99 weight percent of acetic acid and water; and solvent medium irrigation came from a separate system of administration on recycling in the installation, which was characterized by the absence of significant levels of catalyst components. The combined level of water content in the original feed material, formed by the solvent of the filtrate, and the original feed material, formed by the solvent environment, irrigation, was such that the water concentration in the liquid phase reaction medium was approximately mass of 5.8 percent. Oxidant was compressed air supplied essentially at steady flow rate of approximately 352 kilograms per minute. Working pressure is the gas to the top of the reaction vessel was stationary value, approximately at 0.42 MPa overpressure. A reaction chamber functioned essentially adiabatic mode so that the heat of reaction increased the temperature of the incoming source of supply of materials and evaporated significant portion of the solvent. Measured close to the median level height for the reaction environment operating temperature was approximately 154, 6mm°C. the Exhaust stream of a suspension containing crude crude terephthalic acid (CTA)were removed from the area in the vicinity of the bottom of the lower elliptical bottom of the reaction vessel, essentially at steady flow rate of approximately 428 kilograms per minute.

In this example, the ratio between the rate of output of unwanted 4,4'-decarboxylase and the rate of output desired terephthalic acid was measured by the method ghud-MS for three independent samples of a suspension of the product and received approximately to 8.6, and 9.1 and 9.2 h/mn (wt.), thus, on average, gives approximately 9,0 h/mn (wt.). The concentration of para-xylene in the liquid phase of the waste stream of the suspension was measured according to the method of calibrated GC for three individual samples of a suspension of the product and received approximately 777, 539 and 618 h/mn (wt.), thus, on average, gives approximately 645 h/mn(wt.). The concentration of para-Truelove aldehyde in the liquid phase of the waste stream of the suspension was measured according to the method of calibrated GC for these individual samples of a suspension of the product and received approximately 1055, 961 and 977 h/mn (wt.), thus, on average, gives approximately 998 h/mn (wt.).

EXAMPLE 6

Bubble column reactor of this example corresponds to the mechanical configuration, developed in the current example 4. The reactor of this example includes improvements in the level of height, speed, quantity, and diversity of points of introduction of the original feed material, formed para-xylene, which, thus, provides improved distribution of the original feed material, formed para-xylene, and improved granularity level in relation to molecular oxygen. It also includes improvements in the quality of aeration in the reaction medium through the use of improved bubbler oxidant and in the level of height and method for the removal and de-aeration of suspension, leaving the reaction medium. In comparison with example 5, a significant improvement was observed in relation to the release of para-xylene, and a significant decrease is observed in respect of the receipt of impurities.

The reactor of this example, ha what have antiresonance improved mechanical configuration, described in example 4, the CFD model. Work level was about 25 meters of the reaction medium. Steam-xylene technical purity was performed essentially stationary at a flow rate of approximately 81 kilograms per minute. The solvent of the filtrate was applied thoroughly mixed with para-xylene technical purity essentially at steady flow rate of approximately 744 kilograms per minute. The combined stream of the original feed material, formed by the solvent of the filtrate and para-xylene technical purity, therefore, was approximately 825 pounds per minute. The solvent of the filtrate came from the same system of administration on recycling in the plant and was characterized by essentially the same composition as in example 5. The concentration of the catalyst components in the solvent of the filtrate was such that the composition of the liquid phase reaction medium corresponded to approximately 1996 h/mn (wt.) cobalt, about 1693 h/mn (wt.) bromine and approximately 108 hours/mn (wt.) manganese. A separate stream of solvent medium irrigation was applied in the form of droplets in the separation zone gas above the working level of the reaction medium essentially at steady flow rate of approximately 573 kilograms per minute. This solvent medium irrigation consisted of more than approx the positive 99 mass percent of acetic acid and water; and the solvent medium irrigation came from a separate system of administration on recycling in the installation, which was characterized by the absence of significant levels of catalyst components. The combined level of water content in the original feed material, formed by the solvent of the filtrate, and the original feed material, formed by the solvent environment, irrigation, was such that the water concentration in the liquid phase reaction medium was approximately mass of 5.7 percent. Oxidant was compressed air supplied essentially at steady flow rate of approximately 329 kilograms per minute. Working pressure for gas the top of the reaction vessel was stationary value of approximately 0,41 MPa overpressure. A reaction chamber functioned essentially adiabatic mode so that the heat of reaction increased the temperature of the incoming source of supply of materials and evaporated significant portion of the solvent. Measured close to the median level height for the reaction environment operating temperature was approximately 153,3°C.

Reaction medium was collected from the side of the reaction vessel at the level of the height corresponding to approximately 14 meters, through a round hole in the wall, is AutoRAE had an inner diameter, approximately 0,076 meters. Selected reaction medium transported through the essentially horizontal channel, made from piping components, Schedule 10S with a nominal 3 inch side region essentially vertical external deaeration tank. A circular cross-section external deaeration tank, made mainly from the pipe Schedule 10S with nominal 12 inches, had an inner diameter of approximately 0,315 meters. Square horizontal cross-section inside the outer deaerating vessel, therefore, was approximately 0,0779 square meter. It can be associated with a square horizontal cross-section inside the reaction vessel of approximately 4,67 square meter-level height, which make the selection of the reaction medium. Thus, the ratio between the smaller and larger squares horizontal cross-section was approximately 0,017.

External deaeration capacity were down approximately 1.52 meters from the height corresponding to the point of introduction of the reaction medium, and then its diameter was reduced to achieve compliance with the channel for the flow of the lower outlet. For essentially the deaerated slurry containing crude crude terephthalic acid and the walking from the area of lower external deaeration tank, was essentially stationary consumption of approximately 433 kilograms per minute. Thus, for essentially the deaerated suspension at lower levels along the height of the deaeration tank with a nominal 12 inches in the direction from top to bottom was the flow rate per unit cross section of the stream, which was approximately 0,093 meters per second; and capture harmful oxidant in this waste stream of the suspension was observed. The exhaust flow of slurry transported forward through the channel for the flow, made from piping components, Schedule 10S with nominal 3 inches, up to the process connection, located on technological scheme further. In this example, the flow control selected reaction medium was placed on the flow path, leaving the area of the bottom of the deaerating tank, although possible and suitable for use are, and other items control.

External deaeration tank passed upwards by approximately 14 metres from the height corresponding to the point of introduction of the reaction medium, and then the diameter of the pipeline with a nominal value of 12 inches was reduced to achieve compliance with the channel for the flow of the upper outlet, made from piping components, Schedule 10S with nominal 2 inches. The separated gas, is walking from the external deaeration tank, transported through this channel with a nominal 2 inches to a junction with the main stream of the exhaust gas leaving the area of the top of the reaction vessel.

In this example, the ratio between the rate of output of unwanted 4,4'-decarboxylase and the rate of output desired terephthalic acid was measured by the method ghud-MS for the three individual samples of a suspension of the product and received approximately 2.3, and 2.7 and 3.2 h/mn (wt.), that yields an average approximately 2.7 hours/mn (wt.). This is significantly lower value in comparison with example 5. The concentration of para-xylene in the liquid phase of the suspension, the exhaust from the side outlet elevated location, measured according to the method of calibrated GC for three individual samples of a suspension of the product and received approximately 86, 87 and 91 hours/mn (wt.), that yields an average of approximately 88 hours/mn (wt.). The concentration of para-Truelove aldehyde in the liquid phase of the waste slurry was measured by the method of calibrated GC for these individual samples of a suspension of the product and received approximately 467, and 423 442 h/mn (wt.), that yields an average of approximately 444 h/mn (wt.). This corresponds to an improvement of the degree of conversion and yield for selected flow of the suspension in comparison with example 5.

EXAMPLES 7-10

Examples 7-10 are estimated instances, specifically related to the initial dispersion of para-xylene in the reaction medium, but also showing other aspects of the present invention.

EXAMPLE 7

This example relates to the supply of the vaporized para-xylene. In this calculation example, the source of the supplied material formed para-xylene, prior to introduction into the reaction medium is heated and evaporated. This contributes to the initial dispersion of para-xylene. It provides increased feed volumes and facilitates the achievement of higher speeds. In addition, it slows down the transfer of incoming para-xylene in the volume of the liquid phase and leads to the displacement of the original feed material, formed para-xylene, in the direction of the liquid phase reaction medium in greater harmony with gaseous source of supplied material formed by molecular oxygen.

In this example, the capacity of the bubble column reactor oxidation has a vertical cylindrical body, characterized by an inner diameter equal 2,44 meters. The height of the tank bubble column reactor oxidation is 32 meters from the bottom line of the beginning of the bend (TL) to the upper TL. In the areas of the top and bottom of a cylinder capacity will be equipped with elliptical bottoms configuration 2:1. Operating level is approximately 25 the EAN reaction medium above the lower TL. Source of supplied material, formed by the solvent of the filtrate, which is separated from the para-xylene is fed at a flow rate equal to 18.4 pounds per second, through a circular inlet opening, characterized by the diameter 0,076 m, in the wall of the reaction vessel at the level of height, located at 4.35 meters above the lower TL. Consumption when applying solvent medium irrigation in the area of gas separation above the working level of the reaction medium is approximately 14.3 kilograms per second. Flow rate at compressed air through the bubbler oxidant, is essentially the same as in examples 4 and 6, is approximately 9 kilograms per second. The suspension, containing about 31 weight percent of the solid phase, is withdrawn from the reaction medium through the side of the discharge rack, essentially the same as in examples 4 and 6. The pressure in the space above the liquid level of the reaction medium is about 0.50 MPa overpressure. The levels of water content and cobalt, bromine and manganese in the liquid part of the reaction medium are essentially the same as in example 4.

Consumption when applying para-xylene is of 1.84 pounds per second. Before release into the reaction medium stream source feed material formed by the liquid phase of para-xylene, is subjected to environmenta is Yu excess pressure, and then evaporated under a pressure of approximately 0,69 MPa overpressure, as a result of heating from the storage temperature of approximately 40°C, up to a temperature of approximately 233°C. This requires the use of approximately 1.3 mega joules per second of heat applied to the thread of the original feed material, formed para-xylene. For this purpose apply a heat exchanger using steam at a pressure of 4 MPa, but equally sufficient and any other energy source with sufficient temperature, including waste heat process fluid. This heat input represents approximately 5 percent of the heat of reaction conversion of para-xylene to terephthalic acid. The removal of this additional heat load causes a slight rise in the temperature of the reaction medium at constant pressure in relation to the supply of liquid para-xylene (see example 8). Temperature of approximately 162°C according to measurements close to the median level height for the reaction medium. Optional pressure can be reduced for lowering the reaction temperature to 160°C according to measurements close to the median level height for the reaction medium.

Volumetric flow rate of evaporated the aqueous para-xylene is about 0,084 cubic meters per second. This stream is introduced into a reaction chamber at the level of height, located 0.1 meters above the lower TL of the vessel through 3 channels connected in parallel. Adjacent to the reaction capacity of each channel is made of components of the pipeline with a nominal value of 1.5 inches and is connected with a round hole of equal diameter in the vessel wall. 3 holes in the wall have a 120-degree horizontal azimuthal spacing from each other. The flow rate per unit flow for each incoming stream of para-xylene is approximately 21 meters per second, and received para-xylene is dispersed in the reaction medium at the same time until it dissolves in the liquid phase reaction medium, where and are the substance of the catalyst.

EXAMPLE 8

This example relates to the supply of partially evaporated para-xylene. In this calculation example, the source of the supplied material formed para-xylene, prior to introduction into the reaction medium was partially evaporated in the result of mixing with the supplied oxidant. This contributes to the initial dispersion of para-xylene. It provides increased feed volumes and facilitates the achievement of higher speeds; and this leads to the dilution of the concentration of para-xylene. In addition, it slows down the transfer of incoming para-xylene in YEM liquid phase and leads to the displacement of the original feed material, formed para-xylene, in the direction of the liquid phase reaction medium in greater harmony with gaseous source of supplied material formed by molecular oxygen.

In this example, the capacity of the bubble column reactor oxidation has a vertical cylindrical body, characterized by an inner diameter equal 2,44 meters. The height of the tank bubble column reactor oxidation is 32 meters from the bottom line of the beginning of the bend (TL) to the upper TL. In the areas of the top and bottom of a cylinder capacity will be equipped with elliptical bottoms configuration 2:1. Operating level is approximately 25 meters of the reaction medium above the lower TL. Source of supplied material, formed by the solvent of the filtrate, which is separated from the para-xylene is fed at a flow rate equal to 18.4 pounds per second, through a circular inlet opening, characterized by the diameter 0,076 m, in the wall of the reaction vessel at the level of height, located on of 4.35 meters above the lower TL. Consumption when applying solvent medium irrigation in the area of gas separation above the working level of the reaction medium is approximately equal to 12.8 pounds per second. Flow rate at compressed air through the bubbler oxidant, is essentially the same as in examples 4 and 6, is approximately 9 kilograms per second. Suspension, content is concerned about 31 weight percent of the solid phase, is withdrawn from the reaction medium through the side of the discharge rack, similar to that in examples 4 and 6, but modified as described hereinafter. The pressure in the space above the liquid level of the reaction medium is about 0.50 MPa overpressure. The levels of water content and cobalt, bromine and manganese in the liquid part of the reaction medium are essentially the same as in example 4.

Consumption when applying para-xylene again is of 1.84 pounds per second. Para-xylene in a liquid flows through the channels into the interior of the bubbler oxidizer, where the fluid in 4 positions release into the environment of compressed air when using nozzles for spraying liquid, known state of the art. At the point at which the liquid is introduced into the bubbler oxidant, optional you can use the channels for liquids with closed ends or nozzles for gas-liquid dispersion. In order precautions for safety bubbler oxidant place 4 temperature sensor. These temperature sensors are connected to alarm systems and locks to disconnect the supply of oxidizer and para-xylene, if it finds a high temperature. In the presence of compressed air at a temperature of approximately 80°C in the later manifestations of thermal effect of compression and lack aftercooler at the last stage of compression, and if you have the original feed material, formed para-xylene, at a temperature of approximately 40°C, under pressure prevailing in the bubbler oxidant, about 17 weight percent para-xylene to evaporate. The remaining liquid para-xylene is transferred into a reaction medium together with the gas in the form of two-phase flow mixture with gas at velocities approaching the velocity of the gas stream. In addition, the aforementioned remaining liquid helps to wash away from the bubbler oxidant of any amounts of the solid phase, which it entered, in accordance with aspects of the invention.

The temperature is approximately 160°C according to measurements close to the median level height for the reaction medium. Since no additional energy to any thread of the original feed material does not fail, is approximately the same as in examples 4 and 6.

In order to increase the proportion of para-xylene which enters into the reaction medium in the form of steam, before mixing in the bubbler oxidant source or the feed material formed by the compressed air source or the feed material formed para-xylene, optional can be preheated. For example, 300 kilojoules per second heat supplied to steam-XI is Olu, raising its temperature to about 124°C and increases the proportion of instantly evaporated para-xylene to about 33 percent. For example, 600 kilojoules per second heat supplied to the compressed air, raising its temperature to about 146°C and increases the proportion of instantly evaporated para-xylene to about 54 percent. In both cases, for heating requires more than low-grade energy in comparison with what is required in example 7. In fact, as all or part of the heat source you can use the waste heat of the gas exhaust from the reaction environment. However, if the source of the supplied materials to bring a certain amount of energy, then the temperature of the reaction medium will increase, at a stated pressure, flow and stabilizing compositions of the phases in the range from 160 to 162°C according to measurements close to the median level in height. For temperature control is not necessary, you can adjust the pressure. In addition, if the source of the supplied materials will bring a certain amount of energy, then will regulate the amount of solvent fed to the reaction vessel, if it is desirable to withstand the proportion of the solid phase is approximately constant. For example, in order videri the AMB share of the solid phase is approximately constant, close to 31 mass%, in examples 7 and 8, the flow of solvent medium irrigation range from about 12.8 to about 14,3 kilograms per second depending on the amount of energy input.

EXAMPLE 9

This example relates to the supply of para-xylene at a distance from the walls of the reaction vessel using a liquid of eductor. In this calculation example, the initial dispersion of the original feed material, formed of liquid para-xylene, improve the use of eductor using as the driving force of the fluid flow. The reactor of this example has the same mechanical configuration and boundary technological conditions, as in the case of example 4, with the exceptions described hereinafter. Mixed liquid-phase stream of para-xylene plus solvent of the filtrate flows through the wall of the reaction vessel at the same level in height on the same channel to flow with nominal 3 inches. However, the internal distribution of liquid source material supplied from example 4 is not used, and a mixed liquid source supplied material release in the reaction medium as a driving fluid in eductor flow, the known state of the art and demonstrated the ohms on figure 26. Eductor developed for the differential pressure driving the fluid, equal to 0.1 MPa. Eductor come and focus at the exit of the jet expiration vertically upward along the axial center line of the reaction vessel at the level of height, located approximately 4.5 meters above the lower TL. The volume of the reaction medium, eductional and stir with a driving fluid, varies over time depending on stochastic events associated with accumulation of bubbles in a bubble column at the inlet hole of eductor. However Sredneuralskaya value eductional flow exceeds the flow rate for the driving fluid, which thus provides a more rapid dilution of the incoming para-xylene. Subsequent mixing and chemical reaction proceed in accordance with the usual stochastic events in a bubble column.

EXAMPLE 10

This example relates to the supply of para-xylene at a distance from the walls of the reaction vessel when using eductor for gas and liquid. In this calculation example, the initial dispersion of the original feed material, formed para-xylene, improve the use of eductor using as the driving force of the gas stream. The reactor of this example is characterized by the same mechanism, the standard configuration and boundary technological conditions, as in the case of example 4, with the exceptions described hereinafter. Octagonal bubbler oxidant and distribution system of liquid-phase source of supply of material removed. Instead, the incoming oxidant stream and a mixed liquid source supplied material formed para-xylene plus solvent of the filtrate, served through independent channels in the inner space of the reaction vessel. There both streams unite as a driving fluid into the inlet hole in eductor flow, the known state of the art and shown on figure 27. Eductor align in the vertical direction along the axial center line of the reaction vessel. His position when contacting outlet down and have a 0.2 m below the lower line of the beginning of the bending reaction vessel. Eductor designed for differential pressure driving fluid, equal to 0.1 MPa. Close to the area where the first to combine the original supplied materials formed by compressed air and para-xylene, have two temperature sensor. These temperature sensors are connected to alarm systems and locks to disconnect the supply of oxidizer and para-xylene, if it finds a high temperature.

Volume eductional reaction medium increase is in comparison with example 9, and the initial dilution of the incoming para-xylene is additionally improved. In addition, the liquid-phase portion of the reaction medium with maximum local concentrations of para-xylene, more maps directly to a gas phase part with a maximum concentration of molecular oxygen. Subsequent mixing and chemical reaction proceed in accordance with the usual stochastic events in a bubble column.

EXAMPLES 11-13

Examples 11-13 are design examples, in particular, to the use of the flow of liquid from the reaction medium in the channels in order to facilitate the initial dispersion of para-xylene in the reaction medium, but also to demonstrate to other aspects of the present invention.

EXAMPLE 11

This example relates to the use of the channel for the flow in the reaction vessel for transporting fluid in order to facilitate the initial dispersion of the incoming para-xylene. The reactor of this example has the same mechanical configuration and boundary technological conditions, as in the case of example 4, with the exceptions described hereinafter. Reference is made to figure 24. Mixed liquid-phase stream of para-xylene plus solvent of the filtrate passes through the wall of the reaction container of the particular channel to flow with nominal 3 inch, similar to that in example 4. However, the internal distribution of the liquid source feed material of example 4 is removed, and the aforementioned mixed liquid stream free not in it, and in the channel to flow. The channel for the flow of a circular cross-section has an internal diameter equal to approximately 0.15 meters for most of its length, including its lower end, which is located 1 meter above the lower TL of the vessel. The total height of the passage channel for the flow in the vertical direction is 21 meters in counting from the bottom TL capacity. At the height of 20 meters from the bottom TL-capacity channel for the flow expands to the internal cross-section area of 0.5 square meter while passing in height by 1 meter. This top, which has a larger diameter section of the above-mentioned channel for the flow can be seen as internal deaeration capacity, and in fact it is partly form when using the wall of the reaction vessel. The channel for the flow is fully equipped inside the reaction vessel. In the position of the upper inlet channel for the flow of the reaction medium significantly depleted in para-xylene and para-Truelove aldehyde with the simultaneous presence of significant concentrations of para-Truelove acid and 4-carboxybenzene. The reaction among the a, arriving in the area of the top of the mentioned channel for the flow, essentially subjected to deaeration, allowing for more dense medium in the inner space of the above-mentioned channel for the flow in comparison with the rest of the reaction vessel. The suspension in the channel for the flow moves up and down with the flow, according to an estimate of approximately 150 kilograms per second, where in this case the pressure drop in the flow, integrally summarizes the total length of the above-mentioned channel for the flow reaches equilibrium with the difference of densities between internal and external spaces, integral summarizes the total length of the above-mentioned channel for the flow. In this moving downward flow of the slurry to approximately 104 kilograms per second is liquid, which is approximately 69 mass%. The flow of the original feed material, formed thoroughly mixed para-xylene and the solvent of the filtrate, in the aggregate, approximately 20,2 kilograms per second, is introduced into the said channel for flow of approximately 5 meters above the lower TL. Then within less than 1 second this mixture moves down the channel to flow even at 4 meters, which is approximately 27 diameters of the channel and is substantially displaced is Anna. Thus, before release into the main body of the reaction medium in a bubble column, the concentration of para-xylene in a suitable case is reduced to approximately 15000 h/mn (wt.). Subsequent mixing and chemical reaction proceed in accordance with the usual stochastic events in a bubble column.

EXAMPLE 12

This example refers to the use of external reaction vessel channel for the flow to transport the liquid in order to facilitate the initial dispersion of the incoming para-xylene. The reactor of this example has the same mechanical configuration and boundary technological conditions, as in the case of example 11, with the exceptions described hereinafter, and with reference to figure 25. Internal channel for the flow is removed, and replaced with an external channel for the flow. The section of the canal from the reaction vessel with an external deaeration section, has an inner diameter of its circular cross-section of 0.30 meters and is located on 20 meters above the lower TL. The inner diameter of the circular cross-section outer section deaeration is 1 m and its height is 2 meters. The inner diameter of the circular cross section of the channel for the flow below section deaeration is 0.20 m, which makes it possible to achieve more significant the data flow when using the power from approximately the same available level height. In order to regulate the flow rate in the desired range, the channel for the flow of injected air flow sensor and a valve controlling the flow. For example, for transportation of slurry flow regulator mounted on the achievement of 150 kilograms per second, what is the same thing according to the evaluation takes place in the case of internal channel for the flow of example 11. Mixed liquid-phase stream of para-xylene and the solvent of the filtrate is injected into the external channel for flow of approximately 5 meters above the lower TL of the reaction vessel. The outlet of the outer channel for the flow connected with the lower bottom of the reaction vessel. Thus, before release into the main body of the reaction medium in a bubble column, the concentration of para-xylene in a suitable case again reduced to approximately 15000 h/mn (wt.). Subsequent mixing and chemical reaction proceed in accordance with the usual stochastic events in a bubble column. Selection of suspension products for further processing is carried out in a branch of said channel to flow below the deaeration section and above the point of introduction of the liquid-phase stream of para-xylene and the solvent of the filtrate, thus, eliminates the need for separate removal system and de-aeration of suspension.

EXAMPLE 13

This example relates to the use of the channel flow, including sections, both outside and inside the reaction vessel for transporting fluid in order to facilitate the initial dispersion of the incoming para-xylene. This calculated example is identical to example 12 except that the second branch in the outer channel for the flow is located approximately 3 meters above the lower TL of the reaction vessel below the point of introduction of the mixed liquid stream formed by the para-xylene and the solvent of the filtrate. The round cross section of the channel for flow of the second branch also has an inner diameter of 0.20 meters. In the channel for flow of the second branch have a separate valve controlling the flow again to regulate flow. The channel for the flow branches passes through the side wall of the reaction vessel 3 meters above the lower TL, and a channel for the flow branches passes from inside the walls of the reaction vessel by 0.4 meters. Thus, the channel branching section includes both outside and inside the reaction vessel. The thread can enter into a reaction chamber either through the channel release the bottom of the bottom, or through the inner channel of the release of the side wall, or through both channels at once and in any ratio.

The invention has been described in detail, the specific reference to its preferred embodiments, but you must understand that within the scope and essence of the invention is possible to realize a variations and modifications.

1. The method of liquid-phase oxidation, including:
(a) introducing a flow of oxidant containing molecular oxygen, and flow of the source material containing the oxidizable compound in the reaction zone bubble column reactor,
(b) oxidation of oxidizable compounds in the liquid phase of the multiphase reaction medium in the reaction zone to produce in the reaction medium of the solid-phase product,
(c) selecting at least part of the reaction medium containing the aforementioned solid-phase product from the said reaction zone through one or more holes located at a higher level than the zone of injection of at least part of the mentioned molecular oxygen in the reaction zone,
characterized in that the solid-phase product is produced, at least about 10 wt.% oxidizable compounds, supporting the average gas consumption per unit cross section of the stream at half the height of the mentioned reaction medium is equal to at least approximately 0.3 m/s

2. The method according to claim 1, characterized in that the selected reaction medium containing at least about 50 wt.% of the total solid-phase product.

3. The method according to claim 1, characterized in that at least AP is sustained fashion 50 wt.% of said molecular oxygen is introduced into said reaction zone below mentioned holes for the selection of the reaction medium.

4. The method according to claim 1, characterized in that the selected reaction medium, containing essentially all of the solid-phase product, and essentially all of the molecular oxygen is introduced into the reaction zone below the holes for the selection of the reaction medium, where the area of the reaction medium has a maximum height H, and the holes for the selection of the reaction medium is placed at a distance equal to at least about 1H from the bottom of the reaction zone.

5. The method according to claim 1, characterized in that the reaction zone below the holes for the selection of the reaction medium is injected, at least part of the flow of the source material containing the oxidizable compound.

6. The method according to claim 5, characterized in that the selected reaction medium containing at least about 50 wt.% of the total solid-phase product.

7. The method according to claim 5, characterized in that at least approximately 50 wt.% from the flow of the source material containing the oxidizable compound, is introduced into the reaction zone below the holes for the selection of the reaction medium.

8. The method according to claim 5, characterized in that the zone of the reaction medium has a maximum width W, with holes for the selection of the reaction medium is placed at a distance equal to at least approximately 1W from the bottom of the reaction zone.

9. The method according to claim 8, characterized in that essentially all of the molecular oxygen is introduced into the zone is eacli below the holes for the selection of the reaction medium.

10. The method according to claim 5, characterized in that the reaction medium is characterized by a maximum height H, width W, and a ratio H:W, equal to at least approximately 3:1.

11. The method according to claim 10, characterized in that the holes for the selection of the reaction medium is placed at a distance equal to at least approximately 2W, from the bottom of the said reaction zone.

12. The method according to claim 10, characterized in that the ratio H:W is in the range from about 8:1 to about 20:1.

13. The method according to claim 10, characterized in that the main part of the molecular oxygen introduced into said reaction zone within about 0,25W and approximately 0,N from the bottom of the reaction zone.

14. The method according to claim 10, characterized in that at least about 30 wt.% from the stream source material is introduced into the reaction zone at a distance of approximately 1,5W from the bottom position, in which the reaction zone is injected mentioned molecular oxygen.

15. The method according to claim 10, characterized in that the flow of the original feed material in the reaction zone is injected through the many holes in the original feed material, where at least two of the holes for the original feed material spaced vertically from one another at least approximately 0,5W.

Cab according to claim 1, characterized in that the method further includes a deaeration selected through the openings of the reaction medium in the zone of deaeration with getting so essentially, deaerated slurry containing less than about 5 vol.% gas, the deaeration is carried out mainly by the natural buoyancy of the gas phase mentioned reaction medium in the solid and liquid phases mentioned reaction medium.

17. The method according to item 16, wherein the deaeration zone define one or more upright sidewalls deaerating tank, and the maximum area of a horizontal cross-sectional area deaeration is a value less than approximately 25% of the maximum square horizontal cross-sections referred to the reaction zone.

18. The method according to claim 1, characterized in that as oxidizable compounds using an aromatic compound.

19. The method according to claim 1, characterized in that as oxidizable compounds are used paraxylene.

20. The method according to claim 1, characterized in that sredneuralskoe and volumetric average number of solid-phase product from the oxidation reaction medium is from about 5 to about 40 wt.%.

21. The method according to claim 1, characterized in that the oxidation is carried out in the presence of the catalyst system is, containing cobalt.

22. The method according to item 21, wherein said catalyst additionally contains bromine and manganese.

23. The method according to claim 1, characterized in that at least a part of the above mentioned solid product selected from the bubble column reactor, optionally oxidized in the secondary oxidation reactor.

24. The method according to item 23, wherein the said oxidation in the above-mentioned secondary oxidation reactor is carried out at an average temperature of at least about 10°C higher than the temperature oxidation in a bubbling reactor column.

25. The method according to item 23, wherein the said oxidation in the above-mentioned secondary oxidation reactor is carried out at an average temperature above the average temperature for bubble column reactor at a value in the range from approximately 20 to approximately 80°C, and the oxidation bubbling reactor column is carried out at an average temperature in the range from about 140 to about 180°C., and the oxidation in the above-mentioned secondary oxidation reactor is carried out at an average temperature in the range of from about 180 to about 220°C.

26. Installation for liquid-phase oxidation, including:
bubbling reactor column with the shell,
the capacity for reactive environments is, containing solid product, and
channel, intended for transporting selected mentioned reaction medium in a container, the shell of the reactor column defines the length of the reaction zone having upper and lower edges spaced from each other in axial length L, where said reaction zone has a maximum diameter D, where said reaction zone is characterized by the ratio L:D, equal to at least about 6:1,
and jacket are made with one or more openings for introducing a gas-phase stream into said reaction zone,
one or more openings for introducing a liquid-phase stream into said reaction zone and
one or more holes for the selection of reaction medium containing the solid-phase product from the above reaction zone located axially in the direction farther from the lower edge at a higher level relative to the at least one orifice for introducing a vapor stream and at least one opening for introducing a liquid-phase flow,
characterized in that at least one of the holes for the introduction of gas-phase stream is separated from the lower side of the reaction zone at an axial distance less than approximately 0,25D, and the holes for the selection of the reaction medium is located at a distance equal the Ohm, at least approximately 1D from the bottom of the reaction zone.

27. Installation p, characterized in that at least approximately 50% of the holes for the introduction of liquid-phase flow are less than about 2,5D from the hole for the introduction of gas-phase stream that is closest to the bottom edge.

28. Installation p, characterized in that at least approximately 50% of holes for introducing the gas-phase flow are closer to the bottom than the holes for the selection of the reaction medium.

29. Installation p, characterized in that at least approximately 50% of the openings for liquid flow are closer to the bottom than the holes for the selection of the reaction medium.

30. Installation p, characterized in that all the openings for the introduction of gas-phase flow are closer to the bottom than the holes for the selection of the reaction medium, and, in fact, all the openings for the introduction of liquid-phase flow are closer to the bottom edge than said holes for selection of the reaction medium.

31. Installation p, characterized in that the said holes for selection of reaction medium are located at a distance equal to at least approximately 2D from the lower edge of the said reaction zone.

32. Installation p, characterized in that the reaction zone them is that the ratio of L:D in the range from about 8:1 to about 20:1.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and to the obtained crude terephthalic acid. Oxidation is carried out in a bubble column reactor which ensures a highly efficient process at relatively low temperature. Particles of the obtained terephthalic acid, which contains approximately less than 100 parts weight/million of 2,6-dicarboxyfluorenone, have transmission factor at 340 nm (%T340) greater than approximately 25%, additionally contains approximately less than 12 parts weight/million of 4,4-dicarboxystilbene and/or contains approximately less than 400 parts weight/million of isophthalic acid. Particles of the obtained terephthalic acid, characterised by average size ranging from approximately 20 to approximately 150 micrometres, are dissolved in tetrahydrofuran for one minute to concentration of a least approximately 500 parts/million and/or is characterised by average BET surface area greater than approximately 0.6 m2/g.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

37 cl, 36 dwg, 5 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method involves, for example: (a) evaporation of said oxidised discharge stream, containing terephthalic acid, metallic catalyst, impurities, water and solvent, in the first zone of an evaporator to obtain a vapour stream and a concentrated suspension of the discharge stream; and (b) evaporation of the said concentrated suspension of the discharge stream in the second zone of the evaporator to obtain a stream rich in solvent and a high-concentration suspension of the discharge stream, where the said second zone of the evaporator has an evaporator operating at temperature ranging from 20°C to 70°C, where from 75 to 99 wt % of the said solvent and water is removed by evaporation from the said oxidised discharge stream at step (a) and (b); (c) the said high-concentration suspension of the discharge stream is filtered in a zone for separating solid products and liquid to form a filtered product and a mother liquid; (d) washing the said filtered product using washing substances fed into the said zone for separating solid products and liquid to form a washed filtered product and washing filtrate; and dehydration of the said filtered product in the said zone for separating solid products and liquid to form a dehydrated filtered product; where the said zone for separating solid products and liquid has at least one pressure filtration device, where the said pressure filtration device works at pressure ranging from 1 atmosphere to 50 atmospheres; (e) mixing water and optionally extractive solvent with the said mother liquid and with all of the said washing filtrate or its portion in the mixing zone to form an aqueous mixture; (f) bringing the extractive solvent into contact with the said aqueous mixture in the extraction zone to form a stream of extract and a purified stream, where the said metallic catalyst is extracted from the said purified stream.

EFFECT: improved method of extracting metallic catalyst from an oxidised discharge stream obtained during production of terephthalic acid.

36 cl, 3 dwg, 2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a dry residue of aromatic dicarboxylic acid containing 8-14 carbon atoms, suitable for use as starting material for synthesis of polyester, where the said method involves the following sequence of stages, for example: (a) oxidation of aromatic material in the oxidation zone to obtain a suspension of carboxylic acid; (b) removal of impurities from the suspension of aromatic dicarboxylic acid in the liquid-phase mass-transfer zone where at least 5% liquid is removed, with formation of a residue or suspension of aromatic dicarboxylic acid, and a stream of mother solution, where the liquid-phase mass-transfer zone includes a device for separating solid substance and liquid; (c) removal of residual impurities from the suspension or residue of aromatic dicarboxylic acid obtained at stage (b) in the zone for countercurrent washing with a solvent to obtain a residue of aromatic dicarboxylic acid with the solvent and a stream of mother solution together with the solvent, where the number of steps for countercurrent washing ranges from 1 to 8, and the countercurrent washing zone includes at least one device for separating solid substance and liquid, and the said solvent contains acetic acid, (d) removal of part of the solvent from the residue of aromatic dicarboxylic acid together with the solvent obtained at stage (c) in the zone for countercurrent washing with water to obtain a residue of aromatic dicarboxylic acid wetted with water and a stream of liquid by-products together with the solvent/water, where the number of countercurrent washing ranges from 1 to 8, and the countercurrent washing zone includes at least one device for separating solid substance and liquid, where stages (b), (c) and (d) are combined into a single liquid-phase mass-transfer zone, and directing the residue of aromatic dicarboxylic acid wetted with water directly to the next stage (e), (e) drying the said residue of aromatic dicarboxylic acid wetted with water in the drying zone to obtain the said dry residue of aromatic dicarboxylic acid suitable for synthesis of polyester, where the said residue wetted with water retains the form of residue between stages (d) and (e).

EFFECT: design of an improved version of the method of preparing dry residue of aromatic dicarboxylic acid.

21 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a continuous stepped counterflow method of catalytic oxidation in a solvent of at least one benzene compound, containing two substituting groups, which are selected from alkyl, hydroxyalkyl, aldehyde, carboxyl groups and their mixtures, which can be oxidised to the corresponding acid derivative, involving the following steps: (a) introducing a mixture of material into the first oxidation step, containing at least part of the total amount of each of: (i) solvent, which is an organic acid, (ii) at least one catalytically active metal, selected from manganese, cobalt, nickel, zirconium, hafnium, cerium and their mixtures, and (iii) bromine in molar ratio, in terms of all catalytically active metals, in the interval from 1:20 to 5:1 and from 7 to 60 wt % of the total amount of at least one disubstituted benzene, introduced at steps (a) and (d); (b) partial oxidation of at least one disubstituted benzene at the first oxidation step in the presence of a gas, containing molecular oxygen initially in amount of 3 to 20 vol. %, at temperature ranging from 121°C to 205°C and relative quantities of disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 25 to 99.95 wt % disubstituted benzene, added at the first oxidation step, is oxidised with formation of a gaseous mixture, containing unreacted molecular oxygen, evaporated solvent and a first mixture of products, containing acid derivative, partially oxidised disubstituted benzene, unreacted disubstituted benzene and solvent, and at pressure from 8.96·105 to 14.8·105 Pa, sufficient for keeping disubstituted benzene, partially oxidised disubstituted benzene, acid derivative and solvent in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 0.3 to 2 vol. %; (c) extraction of the obtained first product mixture after the first oxidation step and supplying at least part of the extracted first product mixture to the second oxidation step; (d) supplying gas to the second oxidation step, containing molecular oxygen and residue form total amount of disubstituted benzene, catalytic metal, solvent and bromine; (e) oxidation at the second oxidation step of partially oxidised disubstituted benzene and unreacted disubstituted benzene, supplied to the second oxidation step, with a gas containing molecular oxygen in amount of 15 to 50 vol. %, at temperature ranging from 175°C to 216°C and relative quantities of disubstituted benzene, partially oxidised disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 96 to 100 wt % disubstituted benzene and partially oxidised disubstituted benzene is oxidised with formation of a gaseous mixture, which contains unreacted molecular oxygen, evaporated solvent and a second product mixture, containing acid derivative and solvent, and at pressure from 11.7·105 to 16.2·105 Pa so as to keep the acid derivative, partially oxidised disubstituted benzene and unreacted disubstituted benzene mainly in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 3 to 15 vol. %; (f) extraction after the second oxidation step of the second product mixture, containing acid derivative; and (g) tapping gas which contains residual molecular oxygen after the second oxidation step and returning it to the first oxidation step.

EFFECT: method allows for maximum use of oxygen without reducing quality of the desired carboxylic acid using a stepped counterflow oxidation system.

25 cl, 11 tbl, 29 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to the improved method for oxidising of aromatic hydrocarbon such as para-xylol, meta-xylol, 2,6-dimethylnaphthalene or pseudocumene with forming of corresponding organic acid. The oxidation is implemented by the source of molecular oxygen in liquid phase at temperature range from 50°C to 250°C in the presence of catalyst being a) oxidation catalyst based on at least one heavy metal representing cobalt and one or more additive metals being selected from manganese, cerium, zirconium, titanium, vanadium, molybdenum, nickel and hafnium; b) bromine source; and c) unsubstituted polycyclic aromatic hydrocarbon. The invention refers also to the catalytic system for obtaining of organic acid by the liquid-phase oxidation of aromatic hydrocarbons representing: a) oxidation catalyst based on at least one heavy metal representing cobalt and one or more additive metals being selected from manganese, cerium, zirconium, titanium, vanadium, molybdenum, nickel and hafnium; b) bromine source; and c) unsubstituted polycyclic aromatic hydrocarbon.

EFFECT: activation of the aromatic hydrocarbons oxidation increasing the yield of target products and allowing to decrease the catalyst concentration and the temperature of the process.

45 cl, 4 tbl, 16 ex

FIELD: chemistry.

SUBSTANCE: method of obtaining product - purified carboxylic acid, includes: (a) oxidation of aromatic initial materials in primary oxidation zone with formation of raw carboxylic acid suspension; where raw carboxylic acid suspension contains terephthalic acid; where said oxidation is carried out at temperature within the range from 120°C to 200°C; (b) withdrawal of admixtures from raw suspension of carboxylic acid, removed at temperature from 140°C to 170°C from stage of oxidation of paraxylol in primary oxidation zone and containing terephthalic acid, catalyst, acetic acid and admixtures, realised in zone of solid products and liquid separation with formation of mother liquid flow and product in form of suspension; where part of said catalyst in said suspension of raw carboxylic acid is removed in said mother liquid flow; and where into said zone of solid products and liquid separation optionally additional solvent is added; (c) oxidation of said product in form of suspension in zone of further oxidation with formation of product of further oxidation; where said oxidation is carried out at temperature within the range from 190°C to 280°C; and where said oxidation takes place in said zone of further oxidation at temperature higher than in said primary oxidation zone; (d) crystallisation of said product of further oxidation in crystallisation zone with formation of crystallised product in form of suspension; (e) cooling of said crystallised product in form of suspension in cooling zone with formation of cooled suspension of purified carboxylic acid; and (i) filtration and optionally drying of said cooled suspension of purified carboxylic acid in filtration and drying zone in order to remove part of solvent from said cooled suspension of carboxylic acid with obtaining of said product - purified carboxylic acid.

EFFECT: purified carboxylic acid with nice colour and low level of admixtures, without using stages of purification like hydration.

8 cl, 1 tbl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention pertains to improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid, which is terephtalic acid. Method involves: (1) supplying (i) p-xylene (ii) water acetic acid reaction medium, containing oxidation catalyst, containing source of cobalt, manganese and bromine source, dissolved in it, and (iii) acid containing gas in the first oxidation zone at high pressure, in which there is liquid phase, exothermal oxidation of p-xylene. In the first reactor, oxidation at high temperature and pressure is maintained at 150-165°C and 3.5-13 bars respectively; (2) removal from the upper part of the first reactor of vapour, containing water vapour, acetic acid reaction medium and oxygen depleted gas, and directing the vapour into the column for removing water; (3) removal from the lower part of the column for removing water of liquid, containing partially dehydrated acetic acid solution; (4) removal from the lower part of the first reactor of the oxidation product, containing (i) solid and dissolved terephtalic acid, 4-carboxybenzaldehyde and p-toluic acid, (ii) water acetic acid reaction medium, containing oxidation catalyst dissolved in it; (5) supplying (i) product of oxidation from stage (4), (ii) oxygen containing gas and (iii) solvent in vapour form, containing acetic acid, obtained from a portion of partially dehydrated acetic acid solvent from stage (3) into the second oxidation zone high pressure, in which there is liquid phase exothermal oxidation of 4-carboxybenzaldehyde and p-toluic acid, where temperature and pressure in the second reactor of oxidation at high pressure is maintained at 185-230°C and 4.5-18.3 bars respectively; (6) removal from the upper part of the second reactor of vapour, containing water vapour, acetic acid reaction medium, and oxygen depleted gas; (7) removal from the lower part of the second reactor of the product of second oxidation, containing (i) solid and dissolved terephtalic acid and (ii) water acetic acid reaction medium; and (8) separation of terephtalic acid from (ii) water acetic acid reaction medium from stage (7) with obtaining of terephtalic acid. The invention also relates to methods of obtaining terephtalic acid (versions). The obtained product is terephtalic acid, with an overall concentration of 4-carboxybenzaldehyde and p-toluic acid of 150 ppm or less.

EFFECT: improved method of lowering content of 4-carboxybenzoldehyde and p-toluic acid in benzenedicarboxylic acid and obtaining terephtalic acid.

13 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention pertains to the perfection of the method of regulating quantities of dissolved iron in liquid streams during the process of obtaining aromatic carboxylic acids or in the process of cleaning technical aromatic carboxylic acids, characterised by that, to at least, part of the liquid stream for regulating the quantity of dissolved iron in it, at least one peroxide with formula R1-O-O-R2 is added. Here R1 and R2 can be the same or different. They represent hydrogen or a hydrocarbon group, in quantities sufficient for precipitation of the dissolved iron from the liquid. The invention also relates to the perfection of the method of obtaining an aromatic carboxylic acid, through the following stages: A) contacting the crude aromatic material which can be oxidised, with molecular oxygen in the presence of an oxidising catalyst, containing at least, one metal with atomic number from 21 to 82, and a solvent in the form of C2-C5 aliphatic carboxylic acid in a liquid phase reaction mixture in a reactor under conditions of oxidation with formation of a solid product. The product contains technical aromatic carboxylic acid, liquid, containing a solvent and water, and an off-gas, containing water vapour and vapour of the solvent; B) separation of the solid product, containing technical aromatic carboxylic acid from the liquid; C) distillation of at least part of the off gas in a distillation column, equipped with reflux, for separating vapour of the solvent from water vapour. A liquid then forms, containing the solvent, and in the upper distillation cut, containing water vapour; D) returning of at least, part of the liquid from stage B into the reactor; E) dissolution of at least, part of the separated solid product, containing technical aromatic carboxylic acid, in a solvent from the cleaning stage with obtaining of a liquid solution of the cleaning stage; F) contacting the solution from the cleaning stage with hydrogen in the presence of a hydrogenation catalyst and under hydrogenation conditions, sufficient for formation of a solution, containing cleaned aromatic carboxylic acid, and liquid, containing a cleaning solvent; G) separation of the cleaned aromatic carboxylic acid from the solution, containing the cleaning solvent, which is obtained from stage E, with obtaining of solid cleaned aromatic carboxylic acid and a stock solution from the cleaning stage; H) retuning of at least, part of the stock solution from the cleaning stage, to at least, one of the stages B and E; I) addition of at least, one peroxide with formula R1-O-O-R2, where R1 and R2 can be the same or different, and represent hydrogen or a hydrocarbon group, in a liquid from at least one of the other stages, or obtained as a result from at least one of these stages, to which the peroxide is added, in a quantity sufficient for precipitation of iron from the liquid.

EFFECT: controlled reduction of the formation of suspension of iron oxide during production of technical aromatic acid.

19 cl, 1 dwg, 6 ex, 4 tbl

FIELD: carbon materials and hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention relates to improved crude terephthalic acid purification process via catalyzed hydrogenating additional treatment effected on catalyst material, which contains at least one hydrogenation metal deposited on carbonaceous support, namely plane-shaped carbonaceous fibers in the form of woven, knitted, tricot, and/or felt mixture or in the form of parallel fibers or ribbons, plane-shaped material having at least two opposite edges, by means of which catalyst material is secured in reactor so ensuring stability of its shape. Catalyst can also be monolithic and contain at least one catalyst material, from which at least one is hydrogenation metal deposited on carbonaceous fibers and at least one non-catalyst material and, bound to it, supporting or backbone member. Invention also relates to monolithic catalyst serving to purify crude terephthalic acid, comprising at least one catalyst material, which contains at least one hydrogenation metal deposited on carbonaceous fibers and at least one, bound to it, supporting or backbone member, which mechanically supports catalyst material and holds it in monolithic state.

EFFECT: increased mechanical strength and abrasion resistance.

8 cl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and to the obtained crude terephthalic acid. Oxidation is carried out in a bubble column reactor which ensures a highly efficient process at relatively low temperature. Particles of the obtained terephthalic acid, which contains approximately less than 100 parts weight/million of 2,6-dicarboxyfluorenone, have transmission factor at 340 nm (%T340) greater than approximately 25%, additionally contains approximately less than 12 parts weight/million of 4,4-dicarboxystilbene and/or contains approximately less than 400 parts weight/million of isophthalic acid. Particles of the obtained terephthalic acid, characterised by average size ranging from approximately 20 to approximately 150 micrometres, are dissolved in tetrahydrofuran for one minute to concentration of a least approximately 500 parts/million and/or is characterised by average BET surface area greater than approximately 0.6 m2/g.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

37 cl, 36 dwg, 5 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: group of inventions relates to liquid-phase catalytic oxidation of an aromatic compound and a reactor-type bubble column. A stream of starting material containing an oxidisable compound and an stream of oxidising agent containing molecular oxygen are fed into the reaction zone of a reactor-type bubble column with maximum height H and maximum width W. At least a portion of the said oxidisable compound is oxidised in liquid-phase by a multiple-phase reaction medium in the reaction zone when at least part of the reaction medium comes into contact with at least one deflector placed in the reaction zone. At least approximately 10 wt % of the oxidisable compound is converted to solid substance in the reaction medium. The ratio H:W of the column is at least approximately equal to 6:1. At least approximately 30 wt % of the oxidisable compound is fed into the reaction zone at a distance of approximately 1.5 H from the lowest mark for inlet of molecular oxygen into the reaction zone. When the oxidisable compound is paraxylene and the oxidation reaction product is crude terephthalic acid, the said product can be purified and extracted using methods which are cheaper than methods which would be used if the product were to be obtained via high-temperature oxidation.

EFFECT: more efficient and cheaper oxidation of the oxidisable compound at relatively low temperature.

38 cl, 58 dwg, 4 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: group of inventions relates to oxidation of para-xylene to obtain crude terephthalic acid and a reactor type bubble column. Mainly a gas-phase stream of oxidising agent containing molecular oxygen, and mainly a liquid-phase stream of initial materials containing para-xylene are fed into a reaction zone with maximum diametre D of the reactor type bubble column, and part of the para-xylene is oxidised in liquid phase of the multi-phase reaction medium contained in the reaction zone to obtain crude terephthalic acid. The initial materials are fed into the reaction zone through several inlet openings, at least two of which are spaced out from each other vertically by at least approximately 0.5D. At least part of the reaction zone is defined by one or more vertically lying side walls of the bubble column. At least approximately 25 wt % of para-xylene is fed into the said reaction zone in one or more places lying inside from the vertical side walls at a distance of at least 0.5D. Oxidation is carried out in the volume of the reaction medium with maximum height H, maximum width W and ratio H:W equal to at least approximately 3:1.

EFFECT: more efficient and economical liquid-phase oxidation of an oxidised compound at relatively low temperatures.

31 cl, 35 dwg, 7 tbl, 13 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing gold catalysts on a porous metal oxide support and aurichlorohydric acid as a precursor, a catalyst and its use for oxidising alcohols, aldehydes, polyhydroxy compounds and carbohydrates. Described is a method of making a supported gold catalyst, involving the following steps: a) preparation of the support in dry form, b) bringing the support into contact with a solution of precursor-aurichlorohydric acid, wherein the maximum volume of the solution is as great as the pore volume of the support, so that an impregnated catalyst precursor is obtained, and c) drying the impregnated catalyst precursor, where in aqueous solution of the precursor aurichlorohydric acid is a HAuCl4 solution and aqueous hydrochloric acid with acid concentration ranging from 0.1 mol/l to 12 mol/l. Described is a catalyst prepared using said method, its use to oxidise organic compounds, including for producing aldonic acids.

EFFECT: increased activity and selectivity of the catalyst.

16 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a continuous stepped counterflow method of catalytic oxidation in a solvent of at least one benzene compound, containing two substituting groups, which are selected from alkyl, hydroxyalkyl, aldehyde, carboxyl groups and their mixtures, which can be oxidised to the corresponding acid derivative, involving the following steps: (a) introducing a mixture of material into the first oxidation step, containing at least part of the total amount of each of: (i) solvent, which is an organic acid, (ii) at least one catalytically active metal, selected from manganese, cobalt, nickel, zirconium, hafnium, cerium and their mixtures, and (iii) bromine in molar ratio, in terms of all catalytically active metals, in the interval from 1:20 to 5:1 and from 7 to 60 wt % of the total amount of at least one disubstituted benzene, introduced at steps (a) and (d); (b) partial oxidation of at least one disubstituted benzene at the first oxidation step in the presence of a gas, containing molecular oxygen initially in amount of 3 to 20 vol. %, at temperature ranging from 121°C to 205°C and relative quantities of disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 25 to 99.95 wt % disubstituted benzene, added at the first oxidation step, is oxidised with formation of a gaseous mixture, containing unreacted molecular oxygen, evaporated solvent and a first mixture of products, containing acid derivative, partially oxidised disubstituted benzene, unreacted disubstituted benzene and solvent, and at pressure from 8.96·105 to 14.8·105 Pa, sufficient for keeping disubstituted benzene, partially oxidised disubstituted benzene, acid derivative and solvent in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 0.3 to 2 vol. %; (c) extraction of the obtained first product mixture after the first oxidation step and supplying at least part of the extracted first product mixture to the second oxidation step; (d) supplying gas to the second oxidation step, containing molecular oxygen and residue form total amount of disubstituted benzene, catalytic metal, solvent and bromine; (e) oxidation at the second oxidation step of partially oxidised disubstituted benzene and unreacted disubstituted benzene, supplied to the second oxidation step, with a gas containing molecular oxygen in amount of 15 to 50 vol. %, at temperature ranging from 175°C to 216°C and relative quantities of disubstituted benzene, partially oxidised disubstituted benzene, catalytic metal, solvent and bromine, introduced at step (a), so that from 96 to 100 wt % disubstituted benzene and partially oxidised disubstituted benzene is oxidised with formation of a gaseous mixture, which contains unreacted molecular oxygen, evaporated solvent and a second product mixture, containing acid derivative and solvent, and at pressure from 11.7·105 to 16.2·105 Pa so as to keep the acid derivative, partially oxidised disubstituted benzene and unreacted disubstituted benzene mainly in liquid state or in form of a suspension of solid substance in a liquid, so that concentration of residual molecular oxygen in the remaining gaseous mixture ranges from 3 to 15 vol. %; (f) extraction after the second oxidation step of the second product mixture, containing acid derivative; and (g) tapping gas which contains residual molecular oxygen after the second oxidation step and returning it to the first oxidation step.

EFFECT: method allows for maximum use of oxygen without reducing quality of the desired carboxylic acid using a stepped counterflow oxidation system.

25 cl, 11 tbl, 29 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method for prolonged heterogeneously catalysed partial oxidation of propene to acrylic acid in gaseous phase, in which the initial gaseous reaction mixture 1, containing propene, molecular oxygen and at least one inert gas, where molecular oxygen and propene are in molar ratio O2:C3H6≥1, is first passed through a fixed catalyst bed 1 at high temperature at the first stage of the reaction, where the active mass of the catalysts is at least one multimetal oxide, containing molybdenum and/or tungsten, as well as at least one element from a group consisting of bismuth, tellurium, antimony, tin and copper, so that, conversion of propene in a single passage is ≥93 mol % and associated selectivity of formation of acrolein, as well as formation of acrylic acid by-product together is ≥90 mol %, temperature of the product gaseous mixture 1 leaving the first reaction stage is reduced if necessary through direct and/or indirect cooling, and if necessary, molecular oxygen and/or inert gas is added to the product gaseous mixture 1, and after that, the product gaseous mixture 1, acting as initial reaction mixture 2, which contains acrolein, molecular oxygen and at least one inert gas, where molecular oxygen and acrolein are in molar ratio O2:C3H4O≥0.5, is passed through a second fixed catalyst bed 2 at high temperature at the second reaction stage, where the active mass of the catalysts is at least one multimetal oxide, containing molybdenum and vanadium so that, conversion of acrolein in a single passage is ≥90 mol % and selectivity of the resultant formation of acrylic acid at both stages is ≥80 mol % in terms of converted propene, and temperature of each fixed catalyst bed is increased independently of each other. Partial oxidation in gaseous phase is interrupted at least once and at temperature of fixed catalyst bed 1 ranging from 250 to 550°C and temperature of fixed catalyst bed 2 ranging from 200 to 450°C, gaseous mixture G, which consists of molecular oxygen, inert gas and water vapour if necessary, is first passed through fixed catalyst bed 1, and then, if necessary, through an intermediate cooler and then finally through fixed catalyst bed 2, in which at least a single interruption takes place before temperature of the fixed catalyst bed 2 increases by 8°C or 10°C, wherein prolonged increase of temperature by 8°C or 10°C, is possible when virtual passage of temperature of the fixed catalyst bed in the period of time on the leveling curve running through the measuring point using the Legendre-Gauss method of the least sum of squares of errors, temperature increase of 7°C or 10°C is achieved.

EFFECT: method increases service life of catalyst.

24 cl, 1 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to improvement of the method of producing (meth)acrylic acid or (meth)acrolein through gas-phase catalytic oxidation of at least one oxidisable substance, chosen from propylene, propane, isobutylene and (meth)acrolein, molecular oxygen or a gas, which contains molecular oxygen, using a multitubular reactor, with such a structure that, there are several reaction tubes, with one (or several) catalytic layer (catalytic layers) in the direction of the axis of the tube, and a coolant can flow outside the said reaction tubes so as to regulate temperature of reaction, in which temperature of the said reaction of gas-phase catalytic oxidation is increased by varying temperature of the coolant at the inlet for regulating temperature of the reaction, while (1) temperature of coolant at the inlet for regulating temperature of the reaction is varied by not more than 2°C for each variation as such, and (2) when variation is done continuously, the time interval from the variation operation, directly preceding the present, is not more than 10 minutes, and, in addition, the difference between the maximum value of peak temperature of reaction of the catalyst layer of the reaction tube and temperature of the coolant at the inlet for regulating temperature of reaction is not less than 20°C.

EFFECT: method in which sharp increase of temperature is suppressed even after changing reaction conditions with aim of increasing temperature for improving efficiency, thus preventing catalyst deactivation, and achieving stable output.

3 cl, 5 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of carrying out heterogenous catalytic partial oxidation in gas phase of acrolein into acrylic acid, during which reaction gas mixture, containing acrolein, molecular oxygen and at least one inert gas-thinner, is passed through having higher temperature catalytic still layer, whose catalysts are made in such way that their active mass contains at least one oxide of multimetal, containing elements Mo and V, and in which during time, temperature of catalytic still layer is increased, partial oxidation in gas phase being interrupted at least once and at temperature of catalytic still layer from 200 to 450°C acrolein-free, containing molecular oxygen, inert gas and, if necessary, water vapour, as well as, if necessary, CO, gas mixture of G oxidative action is passed through it, at least one interruption being performed before increase of catalytic still layer temperature constitutes 2°C or 4°C or 8°C or 10°C during a long period of time, temperature increase constituting 2°C or 4°C or 8°C or 10°C over a long period of time occurring when in plotting factual course of temperature of catalytic still layer during time on laid through measurement points equation curve according to elaborated by Legendre and Gauss method of the least sum of error squares 2°C or 4°C or 8°C or 10°C temperature increase is achieved.

EFFECT: ensuring spread of hot point with time which is less than in previous methods.

21 cl, 3 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing (met)acrolein and/or (met)acrylic acid through heterogeneous catalytic partial oxidation in gaseous phase, in which a fresh fixed-bed catalyst at 100-600°C in a reactor is loaded with a mixture of loading gas, which along with at least, one C3/C4 organic precursor compound subject to partial oxidation and oxidation with molecular oxygen, contains at least one gas-diluent. The process is carried out after establishing content of the mixture of loading gas at constant conversion of organic precursor compound and at constant content of the mixture of loading gas initially in the input period for 3-10 days with load of 40-80% of higher final load, and then at higher filling load of the catalyst with a mixture of loading gas. In the input period, maximum deviation of conversion of organic precursor compound from arithmetic time-averaged and maximum deviation of the volume ratio of one component of the mixture loading gas, oxidising agent, organic precursor compound and gas-diluent, from the arithmetic time-averaged volume ratio of the corresponding component of the mixture of loading gas should not exceed ±10% of the corresponding arithmetic mean value.

EFFECT: method allows for eliminating shortcomings of previous technical level.

3 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to an improved method of monitoring and/or controlling the process of producing (meth)acrolein and/or (meth)acrylic acid through partial oxidation in a gas of C3- and/or C4- precursor compounds in the presence of heterogeneous catalyst in form of particles, in a reactor with two or more vertical thermo-plates, placed parallel each other, forming gaps between them. A heterogeneous catalyst in form of particles is put in the gaps. The gaseous reaction mixture is passed through the gaps. The controlled and/monitored value chosen is one or several temperature values, which are measured in one or several gaps, in one or several points of measurement, which are distributed along the height of each gap.

EFFECT: provision for homogeneity of measured temperature zones with the aim of controlling the process.

25 cl, 7 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to liquid-phase catalytic oxidation of an aromatic compound and to the obtained crude terephthalic acid. Oxidation is carried out in a bubble column reactor which ensures a highly efficient process at relatively low temperature. Particles of the obtained terephthalic acid, which contains approximately less than 100 parts weight/million of 2,6-dicarboxyfluorenone, have transmission factor at 340 nm (%T340) greater than approximately 25%, additionally contains approximately less than 12 parts weight/million of 4,4-dicarboxystilbene and/or contains approximately less than 400 parts weight/million of isophthalic acid. Particles of the obtained terephthalic acid, characterised by average size ranging from approximately 20 to approximately 150 micrometres, are dissolved in tetrahydrofuran for one minute to concentration of a least approximately 500 parts/million and/or is characterised by average BET surface area greater than approximately 0.6 m2/g.

EFFECT: product can be extracted and purified using methods which are cheaper than those which can be used if the acid is obtained via a high-temperature oxidation method.

37 cl, 36 dwg, 5 tbl, 1 ex

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