Method of oxidising alkyl aromatic compounds

FIELD: chemistry.

SUBSTANCE: invention relates to a method and a mixture for oxidising an alkyl aromatic compound. The mixture contains: an alkyl aromatic compound, a solvent, a bromine source, a catalyst and ammonium acetate; wherein the solvent includes a carboxylic acid having 1-7 carbon atoms and optionally water, and the catalyst substantially consists of at least one metal selected from cobalt, titanium, manganese, chromium, copper, nickel, vanadium, iron, molybdenum, tin, cerium and zirconium, present in form of acetates or hydrates thereof.

EFFECT: present invention enables to obtain products of higher purity which enables to eliminate or minimise purification costs.

10 cl, 1 tbl, 3 ex

 

This application claims the priority of provisional application US 61/360,281 which was filed June 30, 2010.

The technical field to which the invention relates.

The present invention relates to methods and compounds suitable for the oxidation of alkylaromatic compounds. More specifically the invention relates to the oxidation of alkylaromatic compounds in the presence of a solvent, a catalyst, a source of bromide and ammonium acetate.

Prior art

The oxidation of alkylaromatic compounds, for example, toluene and xylenes is an important industrial process. Can be obtained by a variety of oxidation products, including aromatic carboxylic acids, such as terephthalic acid (1,4-benzylcarbamoyl acid and isophthalic acid (1,3-benzylcarbamoyl acid), which are used, for example, in the industry of polymers.

US 2833816 reveals the ways oxidation of aromatic compounds to the corresponding aromatic carboxylic acid. In the process of liquid-phase oxidation of alkylaromatic compounds using molecular oxygen, metal or metal ions and bromine or bromide ions in the presence of acid. The metals may include cobalt and/or manganese. Examples of acids are the lower aliphatic monocarboxylic acid containing 1 to 8 carbon atoms, in cast the STI acetic acid.

US 6355835 describes a method of obtaining benzylcarbamoyl acids by liquid-phase oxidation of xylene isomers using oxygen or air oxidation in the presence of acetic acid as solvent, cobalt salts as catalyst and initiator. Stage oxidation is accompanied by distillation of the specified reaction mixture to remove volatiles and cooling and filtration to obtain a crude benzylcarbamoyl acid in the form of a solid product and a filtrate. Also disclosed recrystallization of the crude benzylcarbamoyl acid to produce at least 99% purity and a return to the cycle of the filtrate.

In addition, in the present prior art it is known that the oxidation products, such as aromatic aldehyde, aromatic alcohols, aromatic ketones and aromatic carboxylic acids can be allocated in a solid form or crystallize under conditions of oxidation and/or by cooling the reaction mixture. Thus, there can be obtained a mixture of oxidation products that require further processing to enhance the purity of the target product. For example, in the production of terephthalic acid, the oxidation product is often called crude terephthalic acid, because it contains impurities, including dyed products and intermediate products of oxidation, in particular, 4-carbox the benzaldehyde (4-CBA). To obtain purified terephthalic acid or terephthalic acid polymer skill in the prior art various stages of cleaning, including washing of the crude terephthalic acid with water and/or solvent, additional stages of oxidation or crystallization and interaction of a solution of dissolved crude terephthalic acid with hydrogen at hydrogenation conditions, which typically include a catalyst containing palladium and carbon. Often use several stages of refinement.

US 7692036 discloses an optimized method and apparatus for more efficient and economical conduct liquid-phase oxidation of oxidizable compounds. Such liquid-phase oxidation is carried out in a bubble column reactor that provides a highly efficient reaction at relatively low temperatures. When the oxidizable compound is para-xylene and the reaction product of the oxidation is crude terephthalic acid (CTA), such CTA can be purified and separated more efficient ways than the usual high-temperature oxidation method.

In the prior art there remains a need for alternative ways of oxidizing alkylaromatic compounds, including oxidation processes, which give an aromatic carboxylic acid. The required oxidation processes, which give the products of higher purity to eliminate or minimize cleanup costs. The obtained products with different ratios of pollutants can give new intermediate substances suitable as raw materials in other applications.

The invention

It was found that the oxidation of alkylaromatic compounds in the presence of ammonium acetate can give a solid oxidation product of a different composition compared to the product obtained in conventional processes. In one implementation of the invention provides a solid oxidation product of higher purity.

In one implementation of the invention is a method for the oxidation of alkylaromatic compounds comprising forming a mixture containing alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate; and contacting the mixture with an oxidizing agent at oxidizing conditions to obtain a solid oxidation product containing at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid; and the solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and the catalyst includes at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium.

In another implementation of the invention is setidle oxidation of alkylaromatic compounds includes: alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate; and the solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and the catalyst includes at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium.

The implementation of the invention

In General, the invention relates to methods and compounds or compositions for the oxidation of alkylaromatic compounds to obtain one or more oxidation products, for example, aromatic aldehydes, aromatic alcohols, aromatic ketones and aromatic carboxylic acids. Examples of ways in accordance with the invention include oxidation of para-xylene to terephthalic acid, the oxidation of ortho-xylene to phthalic acid and the oxidation of meta-xylene to isophthalic acid.

Suitable for the oxidation of alkylaromatic compounds or source materials include aromatic compounds containing at least one benzene ring, at least one alkyl group. Metal, ethyl and ISO-propyl alkyl groups are preferred, but not mandatory alkyl groups. In one implementation of the alkylaromatic compound selected from the group consisting of toluene, par is-xylene, ortho-xylene, meta-xylene. Source materials may include more than one alkylaromatic compounds. Because the oxidation reaction usually takes place in several successive stages of oxidation, suitable starting compound also include partially oxidized intermediate with respect to the desired oxidation product. For example, in the production of terephthalic acid source alkylaromatic materials may include a pair of Truelove acid and/or 4-carboxybenzene (4-CBA).

In one implementation of the invention is a mixture or composition comprising alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate. The solvent comprises a carboxylic acid having 1 to 7 carbon atoms. In one implementation of the carboxylic acid comprises acetic acid. The solvent may include more than one carboxylic acid. For example, the solvent may optionally include benzoic acid. In another implementation of the carboxylic acid solvent is acetic acid.

If necessary, the solvent may optionally contain water. Water can be added to the mixture or formed during the oxidation process. In one implementation, the amount of water is about 0.01-5% wt. relative to the weight carboxylic acid having 1 to atomov carbon. The amount of water may be about 0.1-2% wt. relative to the weight carboxylic acid having 1 to 7 carbon atoms. In one implementation, the ratio of solvent to alkylaromatic compound in the mixture is about 1.5:1 to 6:1 mass. The ratio of solvent to alkylaromatic compound may be about 2:1 to 4:1 mass.

The catalyst includes at least one metal selected from cobalt, manganese, titanium, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium. In one implementation, the catalyst contains cobalt and manganese. The metal can be in the form of inorganic or organic salts. For example, a metal catalyst may be in the form of a salt of carboxylic acid, such as a metal acetate and its hydrates. Examples of catalysts include acetate tetrahydrate cobalt(II) and manganese acetate(II) individually or in combination. In one implementation, the amount of manganese acetate(II) less than the number of acetate tetrahydrate cobalt(II) by mass.

The amount of catalyst used in the invention may vary within wide limits. For example, the amount of cobalt may be about 0.001 to 2 wt%. in relation to the weight of the solvent. In one implementation, the number of cobalt is about 0.05-2% of the mass. in relation to the weight of the solvent. The number Marg the NCA may be about 0.001 to 2 wt%. in relation to the weight of the solvent. In one implementation, the amount of manganese is about 0.05-2% of the mass. in relation to the weight of the solvent. In another implementation, the ratio of cobalt to manganese is 3:1-1:2 by weight in terms of elemental metal.

Sources of bromine, as a rule, are known in the prior art activators of the catalyst and include bromine, bromine ions, for example, HBr, NaBr, KBr, NH4Br; and/or organic bromides which are known to provide bromide ions in oxidation conditions, such as benzylbromide, mono - and dibromohexane acid, bromoacetamide, tetrabromide, ethylenedibromide. In one implementation, the source of bromine is at least one of HBr, NaBr, KBr, NH4Br, benzylbromide, monobromoacetic acid, dibromoquinone acid, bromoacetamide, tetrabromoethane and ethylenedibromide. In another implementation, the source of bromine comprises or essentially consists of hydrogen bromide. The amount of hydrogen bromide may be about 0.01-5% wt. in relation to the weight of the solvent. In another implementation, the amount of HBR is about 0.05-2% of the mass. in relation to the mass of solvent.

The mixture also includes ammonium acetate. In one implementation, the amount of ammonium acetate is about 1-100% of the mass. relative to the weight of the solvent. Thus, in broad is the implementation of the invention is a mixture, comprising alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate, in which the solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and optionally water, and the catalyst includes at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium. In one implementation, the mixture comprises alkylaromatic compound, a solvent comprising acetic acid, and optionally water, a source of bromine, including bromide hydrogen, the catalyst comprising cobalt and manganese, ammonium acetate.

In another implementation of the invention is a method for the oxidation of alkylaromatic compounds, comprising: forming a mixture comprising alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate; and contacting the mixture with an oxidizing agent at oxidizing conditions to obtain oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid. The solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and optionally water and a catalyst comprising at least one metal of cobalt, titanium, manganese, chromium, copper, Nickel, in the hope, iron, molybdenum, tin, cerium and zirconium. In one implementation, the mixture comprises alkylaromatic compound, ammonium acetate, a solvent comprising acetic acid, and optionally water, a source of bromine, including bromide hydrogen, the catalyst comprising cobalt and manganese.

Methods of oxidation in accordance with the invention can be implemented in scale from laboratory experiments to full-scale industrial operations. The method can operate in periodic mode, continuous mode or semi-continuous mode. The above mixture can be formed in various ways. The order of adding the components of the mixture (for example, alkyl aromatic compounds, a solvent, a source of bromine, catalyst and ammonium acetate) is not critical. In one implementation, two or more components may be combined or mixed prior to combining or mixing with other components. At least a portion of the mixture forms a liquid phase, although the dissolution of one or more components of the mixture may not always be completed in the course of the method. The liquid phase can be formed by mixing the components in the environment. In another implementation, the liquid phase is formed when the temperature of the mixture to a temperature of oxidation. The mixture can be formed up to the stage Oka the population in the same or another vessel, which is used at the stage of oxidation. In another implementation, the mixture formed in the oxidation reactor, for example, the addition of various flow components separately and/or combined in a continuous or semi-continuous oxidation reactor. Mixture and/or different threads of the components of the mixture can be heated before mixing them.

Although many conventional methods of oxidation of alkylaromatic compounds, as a rule, are carried out in a mixed phase and often include three phases (for example, solid, gaseous and liquid), they are often referred to in the well-known techniques as "liquid-phase" methods of oxidation, because the conditions of oxidation are supported to save at least part of the mixture in the liquid phase. In the prior art it is also known that the number of phases present may vary in time during the process. Methods in accordance with the present invention can also be carried out in the liquid phase or mixed phase in the same manner as in the prior art.

Conventional liquid-phase oxidation reactors of the prior art can be used to carry out the invention. Examples of reactors include vessels, which may have one or more mechanical stirrer, and a variety of bubble column reactors, such as described in US 7692036. Design, working conditions and control the ü such reactors and the conditions used for the oxidation in the oxidation reaction, including, for example, temperature, pressure, amount of liquid and gas, and corrosive properties of the liquid and gas phases are well known (see, for example, US 7692036 and US 6137001).

The method of the invention also includes at least one stage, contacting the mixture with an oxidizing agent at oxidizing conditions to obtain oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid. Thus, in another implementation, the mixture additionally contains an oxidizing agent. In another implementation, the mixture further includes an oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid. The oxidation product may include aromatic carboxylic acid.

The oxidant suitable for a method, serves as a source of oxygen atoms for the oxidation of alkylaromatic compounds and/or intermediate oxidation product used in oxidizing conditions. Examples of oxidizing agents include peroxides, superoxides and nitrogen compounds containing oxygen, such as nitric acid. In one implementation, the oxidant is a gas containing oxygen, for example air, carbon dioxide, molecule the hydrated oxygen. The gas may be a mixture of gases. The amount of oxygen used in the process preferably is in excess relative to the stoichiometric amount required for the desired oxidation process. In one implementation, the amount of oxygen in contact with the mixture exceeds the stoichiometric amount of about 1.2 to 100 times. If necessary, the amount of oxygen in contact with the mixture exceeds the stoichiometric amount of about 2-30 times.

The oxidation conditions typically include a temperature 125-275°C, pressure range from atmospheric, i.e. the 0 MPa (wt.), up to about 6 MPa (wt.) and the residence time in the range from 5 seconds to 2 weeks. The temperature and pressure of the mixture are within these limits and can be maintained within these limits over time. In another implementation, the temperature is about 175-225°C and can be about 190-235°C. In one implementation, the pressure is about 1.2 to 6.0 MPa (wt.) and may be about 1.5 to 6.0 MPa (wt.). In another implementation, the residence time is from about 10 minutes to about 12 hours. Temperature, pressure and residence time in the oxidation may vary depending on various factors, including, for example, the configuration of the reactor, the size and the fact whether the process is periodic, continuous or polunepreryvnykh the m The oxidation conditions can also vary depending on the oxidation conditions. For example, the use of a certain range of temperatures may allow change the range of time.

In one implementation, the oxidation product obtained in accordance with the present invention, may be deposited, to crystallize or to stand out as a solid in a liquid-phase mixture under oxidizing conditions and/or after cooling of the mixture. Thus, the mixture according to the invention may additionally contain a solid oxidation product. Other compounds, including dyed products and other products of oxidation, can be isolated in solid form or captured solid oxidation products, thereby reducing the purity of the target product. In one implementation, the mixture comprises a liquid phase. The mixture can include a gas phase, for example, when the oxidizing agent is added in the form of gas. The mixture can include a solid phase, for example, a component of the mixture, the oxidation product or undissolved by-product or the product, isolated in solid form in the mixture. In one implementation, the mixture comprises a liquid phase, solid phase and optional gas phase. In another implementation, the mixture comprises a liquid phase and a gas phase.

As indicated above, and will be discussed below, it was found that the invention can be used for gaining the solid oxidation product, having a different composition compared to the product obtained in the usual way. In addition, the invention offers new ways to control the content of various pollutants in the solid oxidation product. In one implementation of the method of the invention further includes the formation of oxidation products in the form of solids, not necessarily in terms of oxidation, to obtain a solid oxidation product and the mother liquor. The solid oxidation product can be formed after cooling of the mixture. The solid oxidation product may be separated from the mother liquor, i.e. the liquid phase and the mother liquor may be recycled and reused at the stage of contact, or other stages of the process, described below.

Methods in accordance with the invention may include one or more additional stages of oxidation. In one implementation, the second oxidation step includes a second temperature oxidation, which is lower than the temperature of the first stage of oxidation. Methods in accordance with the invention may include additional stages of contact, as described above, and/or they can be combined with other oxidation stages, such as conventional oxidation stage of the prior art. Several stages of contact or oxidation can be carried out is sledovatelno and/or in parallel and can be combined with other stages of the method, such as the stage of purification described in the description.

In a sequential implementation of the invention includes a second stage of oxidation, in which part or all of the solid oxidation product, or mother liquor, or a solid oxidation product and the mother liquor obtained in the first stage oxidation to form a second mixture with a second solvent, a second source of bromine, ammonium acetate and the second catalyst. The second mixture is in contact with the second oxidant in the second oxidation conditions to produce a second solid oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid. The second solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and the catalyst includes at least one metal of cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium. The second solvent, the second source of bromine, the second catalyst and the second oxidation conditions can be individually or jointly, equal or different from these parameters, the first stage of oxidation. Optional part of alkylaromatic compounds can be included in the second mixture. Optional elements and optional stages described above for the first is Tadei oxidation, equally applicable to this second stage of oxidation.

In the parallel implementation of the invention additionally includes a second stage of oxidation, forming a second mixture comprising part of alkylaromatic compounds, the second solvent, the second source of bromine and the second catalyst. The second mixture is in contact with the second oxidant in the second oxidation conditions to obtain a second solid oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid. The second solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and the second catalyst comprises at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium. If necessary, the second mixture further comprises ammonium acetate. The second solvent, the second source of bromine, the second catalyst and the second oxidation conditions can be individually or jointly, equal or different from these parameters, the first stage of oxidation. Optional elements and optional stages described above for the first stage of oxidation, equally applicable to this second stage of oxidation.

In another domestic the invention additionally includes the removal of solid oxidation products. Cleaning may include one or more additional stages of separation and purification of the solid oxidation product. Examples of stages of purification include: the Department, on which the solid oxidation product is separated from the mother liquor or other liquid phase, for example, filtration and/or centrifugation; washing, in which the solid oxidation product is washed, for example, water and/or another component of the solvent; drying the solid oxidation product; and the process of hydrogenation. Such additional stages of processing, which will be used in various combinations for the treatment of solid oxidation products of the invention have been described in the General literature and well known to experts in the art (see, for example, the links provided in the description of the prior art).

Cleaning stage of the present invention may optionally include one or several stages of contact with the solvent. Stage of contact with the solvent comprises contacting the solid oxidation product comprising also washed or dried solid oxidation product, with a second solvent comprising at least one component selected from water, carboxylic acids having 1 to 7 carbon atoms, and the mother liquor to obtain a second solid oxidation product. In one implementation of the second the second solvent is chosen from the group consisting of mother liquor, carboxylic acids having 1 to 7 carbon atoms, water, and combinations thereof. Contact with the solvent may be leaching contaminants from the solid oxidation product and/or solid oxidation product may be partially or completely dissolved in the solvent. Contact conditions with the solvent include temperature contact with the solvent. The temperature of contact with the solvent is lower than the temperature of oxidation. In one implementation, the temperature of contact with the solvent, of at least 20°C below the temperature of oxidation. Contact with the solvent may be carried out, for example, in one or more crystallizers, located after the oxidation reactor in some conventional processes. The second solid oxidation product may be produced in solid form, to precipitate or crystallize in the second solvent at the stage of contact with the solvent.

In one implementation of the invention is a method, further comprising contacting the solid product of the oxidation and solution, including the mother solution, in terms of engagement, including a second temperature to obtain a second solid oxidation product and a second mother liquor; a second temperature lower than the temperature of oxidation. Optional what about the method further includes separating the second solid oxidation product from the second mother liquor, and the method may further include cleaning the second solid oxidation product.

The solid oxidation product obtained in accordance with the present invention, can be cleaned by known methods, including the use stage of the hydrogenation. In the example implementation is not required stage hydrogenation. In one implementation, the method includes one or several stages of purification that eliminates stage hydrogenation. Stage cleaning method can be selected from the stages of washing, separating, drying, contacting with the solvent, and combinations thereof.

Examples

Examples are presented to further illustrate certain aspects and advantages of the invention and should not be construed as limiting the scope of the claims of the invention.

Example 1

Experimental procedure: in a fume hood loaded into the reactor Parra specified number of components for this experiment, the reactor sealed. The Parr reactor includes a gas distributor for passing the gas through the hole of 1.6 mm in the fluid mechanical gas stirrer and baffles to ensure thorough mixing. The Parr reactor is placed in a heater at room temperature and connect the gas supply line to the reactor and the fridge at the reactor outlet. During operation, gases out of the reactor through Jolo is ilnik, then through the trap and then through the back pressure regulator. Connect the safety valve with bursting disc and thermocouple to the reactor. Connect the device to the circulation of cooling water in the refrigerator and begin circulation of cooling water. Hold the test pressure Parr reactor at room temperature and 1.4 MPa (wt.) (200 pounds per square inch) using nitrogen to the lack of pressure for 15 minutes. Set the value of the pressure required in the experiment, the regulator back pressure at the reactor outlet and hold the test pressure reactor in a nitrogen atmosphere. Start raising the reactor temperature to a temperature required for the experiment, in an atmosphere of nitrogen. Instructions should be followed for each specific reactor, including the limits of temperature and pressure. When the reactor reaches the desired temperature, begin to add the air with the speed required in the experiment, and to control the temperature and pressure in the reactor during the entire testing time. During the test, the air flow in the reactor support equal to 1250 standard cm3per minute, pressure support at 4.1 MPa (wt.) and the mixer rotation speed is 1600 rpm At the end of the test turn off the heat, stop the air flow and allow the reactor is kladitis. When the reactor is cooled to less than 35°C, open the check valve, stop the supply of cooling water, remove the contents and clean the reactor for solid oxidation product and the mother liquor.

The mother liquor and the products filtered under vacuum to separate solids and liquids. The solids are then mixed with about 100 ml of deionized water at room temperature and decanted. Mixing and decantation of deionized water at room temperature are repeated twice. On the fourth rinsing deionized water heated to about 95°C for 30 minutes and then filtered. Solids dried at 80°C for 8-24 hours before analysis.

Examples 2-3

Examples 2-3 are separate tests carried out using equipment and techniques described in example 1. The components of the mixture, given in grams operating temperature, time, and the results are shown in table 1.

Table 1
Number example23
The temperature oxidation °C200200
The time of oxidation watch 66
The components of the mixture, grams
para-Xylene2020
Glacial acetic acid10080
Water20,4
Ammonium acetate020
Methyl hydrogen0,40,4
Acetate tetrahydrate cobalt(II)0,80,8
Manganese acetate(II)0,60,6
Analysis of the solid product
Terephthalic acid, % wt.98,699,5
4-Carboxybenzene, % of the mass.1,100,37
pair-Tolarova acid, % wt. 0,260,07
Benzoic acid, ppm-mass.2300
4-Hydroxymethylbenzene acid, h/million masses.55583

Example 2 (comparative): make a test without ammonium acetate, to demonstrate the level of impurity content using conventional solvents under standard oxidation conditions.

Example 3: the same oxidation conditions as example 2, except for the replacement of ammonium acetate to a certain amount of acetic acid. The inclusion of ammonium acetate significantly increases the purity of terephthalic acid and reduces the concentration of 4-CBA, p-Truelove acid, benzoic acid and 4-hydroxymethylbenzene acid.

1. The mixture for the oxidation of alkylaromatic compounds, including: alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate; and the solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and optionally water, and a catalyst essentially consists of at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium present in the form of acetates Il is their hydrates.

2. The mixture according to claim 1, in which the alkylaromatic compound selected from the group consisting of toluene, xylene, para-xylene, ortho-xylene and meta-xylene.

3. The mixture according to claims 1-2, in which the catalyst comprises cobalt and manganese, and the ratio of cobalt to manganese in the optional catalyst is about 3:1-1:2 by weight in terms of elemental metal.

4. The method of oxidation of alkylaromatic compounds, including:
forming a mixture comprising alkylaromatic compound, a solvent, a source of bromine, the catalyst and ammonium acetate; and
contacting the mixture with an oxidizing agent at oxidizing conditions to obtain a solid oxidation product comprising at least one substance selected from an aromatic aldehyde, an aromatic alcohol, an aromatic ketone, and an aromatic carboxylic acid;
moreover, the solvent comprises a carboxylic acid having 1 to 7 carbon atoms, and optionally water, and a catalyst essentially consists of at least one metal selected from cobalt, titanium, manganese, chromium, copper, Nickel, vanadium, iron, molybdenum, tin, cerium and zirconium present in the form of acetates or their hydrates.

5. The method according to claim 4, in which the ratio of solvent to the alkylaromatic compound is about 1.5:1 to 6:1 by weight.

6. The method according to claims 4 and 5, in the cat the rum carboxylic acid comprises acetic acid.

7. The method according to claims 4 and 5, in which the oxidant is a gas containing oxygen.

8. The method according to claims 4 and 5, in which the source of bromine is at least one substance selected from HBr, NaBr, KBr, NH4Br, benzylbromide, monobromoacetic acid, dibromoquinone acid, bromoacetamide, tetrabromoethane and ethylenedibromide.

9. The method according to claims 4 and 5, in which the oxidation conditions include a temperature in the range of 125-275°C and a pressure in the range 0-6 MPa (gage).

10. The method according to claims 4 and 5, in which, when the contacts are additionally formed the mother solution and additionally carry out the separation of the solid oxidation product from the mother liquor, contacting the separated solid product oxidation with the second solvent in the conditions of contact with a solvent comprising a second temperature, to obtain a purified solid product oxidation, separation of the purified solid oxidation product from the second solvent, washing and drying the purified solid product oxidation to obtain the final purified product of oxidation.



 

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FIELD: chemistry.

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14 cl, 2 tbl, 44 ex, 4 dwg

FIELD: chemistry.

SUBSTANCE: present invention pertains to new compounds with general formula (I), in which X1 is phenyl, 9-member bicyclic heteroaryl, containing S or O as heteroatoms, or 5-member heteroaryl, containing S or O as heteroatoms, each of which is optionally substituted with one or more substitutes, chosen from halogen or C1-6alkyl, which is optionally substituted with one or more halogens. X2 is phenyl, which is optionally substituted with one or more substitutes, chosen from halogen, or 5-member heteroaryl, containing S or O as heteroatoms. Ar is phenylene, which is optionally substituted with one or more substitutes, chosen from halogen, or C1-6alkyl, phenyl, C1-6alkoxy, each of which is optionally substituted with one or more halogens. Y1 is O or S, and Y2 represents O, Z represents -(CH2)n-, where n equals 1, 2 or 3. R1 is hydrogen or C1-6alkoxy and R2 is hydrogen, C1-6alkyl. The invention also relates to pharmaceutical salts of these compounds or any of their tautomeric forms, stereoisomers, stereoisomer mixtures, including racemic mixtures.

EFFECT: invention also pertains to use of these compounds as pharmaceutical compositions, with effect on receptors, activated by the peroxisome proliferator PPARδ subtype, and to pharmaceutical compositions, containing these compounds (I).

36 cl, 41 ex

FIELD: chemistry.

SUBSTANCE: claimed method of obtaining alkylaromatic monocarboxylic acids involves liquid phase oxidation of dialkyl-substituted aromatic hydrocarbons by oxygen-containing gas in the presence of catalyst at high temperature. Alkyltrimethylammonium bromide with alkyl C14-C16 or their mix at 0.3-0.5 wt % of hydrocarbon weight is used as catalyst. Process is performed at 90-120°C until mass ratio of alkylaromatic acid to alkylaromatic aldehyde in the mix reaches 1:1.3-3.0, then alkylaromatic acid is separated, and unreacted hydrocarbon and aldehyde are returned to the process.

EFFECT: possibility to perform mild partial oxidation of dialkyl-substituted aromatic hydrocarbons selectively by one alkyl group without adding transition metals.

2 cl, 8 ex

FIELD: reagent methods of cleaning waste printed circuit board pickling solutions from copper (II); chemical technology of organic agents.

SUBSTANCE: cleaning is performed by adding to waste solution reagent containing monocarbonic acid of aromatic series or its salt, or anhydride at subsequent forming of sediment of salt of copper (II) with anion of monocarbonic acid of aromatic series.

EFFECT: low cost of method; high purity.

19 cl, 1 tbl,, 7 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing aromatic carboxylic acid ammonium salts by reaction of aromatic carboxylic acid with ammonia in aprotonic solvent medium. Method involves carrying out the reaction in the closed vessel by continuous addition of aromatic carboxylic acid in aprotonic solvent medium and passing gaseous ammonia under condition providing maintenance of ammonia partial pressure in the range from 0.1 to 3 bars and elimination of ammonium salt suspension in aprotonic solvent. Method allows preparing ammonium salts as crystals of a definite size that exhibit narrow distribution by size.

EFFECT: improved preparing method.

9 cl, 1 dwg, 6 ex

The invention relates to the field of fine organic synthesis, particularly to a method of obtaining p-butylbenzoic acid

The invention relates to substituted benzoic acids, in particular to an improved method polucheniya p-oksibenzoynoy acid, which nahodiat used in the manufacture of dyes, pharmaceuticals, upon receipt of liquid-crystal compositions

FIELD: chemistry.

SUBSTANCE: invention relates to methods of destruction of toxic substances, namely to utilisation of toxic chlorine-containing substance 2-(2-chlorobenzylidene)malonodinitrile(CS) with obtaining 2-chlorobenzoic acid, which is a marketable product for synthesis of various organic compounds: pesticides, dyes, medications. Method consists in boiling 2-(2-chlorobenylidene)malononitrile in water solution of potassium permanganate for 3-3.5 hours. After that, mixture is kept at room temperature for 14-16 hours, obtained sediment is washed with hot water. Filtrate is evaporated, acidified with 10-15% hydrochloric acid, sediment from filtrate is washed with water and re-crystallised to obtain 2-chlorobenzoic acid.

EFFECT: invention makes it possible to eliminate toxic reagents from technological process and harmful emissions into atmosphere.

2 ex

FIELD: chemistry.

SUBSTANCE: reactor contains reactor case, and device of air input of distribution type and device of air input of cyclone type are located in lower parts of reactor case, device of air input of distribution type contains a series of tubes of air distribution, and device of air input of cyclone type consists of several tubes of cyclone air input, located below tubes of air distribution, with segment of air output of said tubes of cyclone air input being inclined at 45-60° relative to reservoir case radius. Application of combined device of air input can make liquid at the bottom of reactor rotate under pressure of proper amount of air, in addition reactor has good air dispersion, in such way, preserving materials in suspended state.

EFFECT: reactor improvement.

9 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of converting a raw material stream containing at least one C8 aromatic compound, ortho-xylene, meta-xylene, para-xylene and ethylbenzene, into at least one product stream containing isophthalic acid and terephthalic acid (IPA/TA), which comprises the following steps: a) removing ethylbenzene from said raw material stream to form a raw material stream poor in ethylbenzene; b) removing ortho-xylene from said ethylbenzene-poor raw material stream to form a raw material stream poor in ortho-xylene, containing meta-xylene and para-xylene; c) oxidising said ortho-xylene-poor raw material stream to form a product stream containing IPA/TA in ratio of 0.5% to 99.5% IPA and 0.5% to 99.5% TA; d) drying said product stream in a drier to remove residual solvent and water; e) removing the substantially purified IPA/TA product stream; f) dissolving said product stream; and g) separating said IPA and said TA from said dissolved product stream.

EFFECT: method enables to obtain optimum amounts of IPA and TA from a raw material stream containing at least one C8 aromatic compound, in order to optimise output of IPA and TA.

7 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of filling a longitudinal section of a contact pipe with a homogeneous part of a solid catalyst bed. The method of filling a longitudinal section of a contact pipe with a homogeneous part of a solid catalyst bed, the active mass of which is at least one multielement oxide which contains a) elements Mo, Fe and Bi, or, b) elements Mo and V, or c) element V, and additionally P and/or Sb, or the active mass of which contains elementary silver on an oxide support-article, and which consists of only one type Si, or a homogenised mixture of various types Si of catalytically active moulded articles of a defined geometrical shape or catalytically active moulded articles and inert moulded articles of a defined geometrical shape, wherein the median of the maximum longitudinal dimensions Lsi of the articles of a defined geometrical shape of type Si is characterised by the value Dsi, at least within one type Si of moulded articles of a defined geometrical shape, the following set of conditions M is satisfied, such that 40 to 70% of the total number of moulded articles of a defined geometrical shape belonging to S1, have a maximum longitudinal dimension Lsi, for which the inequality 0.98·Dsi≤Lsi≤1.02·DSi holds, at least 10% of the total number of moulded articles of a defined geometrical shape belonging to Si have a maximum longitudinal dimension Lsi, for which the inequality 0.94·Dsi≤Lsi<0.98·Dsi holds, at least 10% of the total number of moulded articles of a defined geometrical shape belonging to S1 have a maximum longitudinal dimension Lsi for which the inequality 1.02·Dsi<Lsi≤1.10·Dsi holds, less than 5% of the total number of moulded articles of a defined geometrical shape belonging to Si have a maximum longitudinal dimension Lsi for which the inequality 0.94·Dsi>Lsi holds, and less than 5% of the total number of moulded articles of a defined geometrical shape belonging to Si have a maximum longitudinal dimension Lsi for which the inequality 1.10·Dsi<Lsi holds, wherein the sum of all moulded articles of a defined geometrical shape belonging to Si is 100%; described also is a method of loading a contact pipe with a solid catalyst bed, a shell-and-tube reactor, a method for oxidation of an organic compound and a method for synthesis of separate organic compounds.

EFFECT: high selectivity of moulding the final synthesis product.

17 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of organic and petrochemical synthesis, specifically to the technology of producing isophthalic acid and a by-product - formic acid by liquid-phase oxidation with O2 gas in the medium of acetic acid in the presence of a Co and Mn salt catalyst at high temperature and pressure, followed by extraction of isophthalic acid and purification thereof by recrystallisation in a water-acetic solvent, extracting formic acid by distillation from the anhydrous acetic acid condensate formed when cooling the vapour-gas mixture removed from the reaction zone with spent air, where there is oxidation of m-diisopropylbenzene or m-ethyl-isopropylbenzene in three steps while raising temperature in steps in the range of (°C) 130-150; 140-160; 165-185°C, pressure (MPa) 0.3-0.6; 0.6-0.8; 0.9-1.2, overall concentration of the Co-Mn-Ni catalyst (ppm) 800 - 1060; 1000 - 1435; 1250 - 1744; and during air flow through the oxidation zone, concentration of CO/CO2 in the spent gas after each step is kept in the following ranges (vol. %): 0.16, 0.17, 0.18-0.25, 0.26 / 0.24, 0.25, 0.9-1.12, 1.19, 1.20, 1.21; 0.18, 0.2-0.3 / 0.9, 1.1-1.42; 0.2, 0.23-0.42 / 1.15, 1.2-1.6,1.8; 93.2-98.8% content of isophthalic acid in oxidation products extracted from the cooled oxidation product of step 3 is achieved, after which process isophthalic acid is purified by successive recrystallisation in CH3COOH while heating the suspension to 180-200°C, and then in H2O while heating the suspension to 200-230°C to obtain highly pure isophthalic acid, and formic acid formed during the oxidation process is extracted from the vapour-gas mixture from the oxidation reactor by cooling the vapour-gas mixture to 30-40°C, separating the formed condensate and treatment thereof with n-butyl acetate in ratio of acid to n-butyl acetate of 1:0.17; further, reaction water in form of its azeotropic mixture with n-butyl acetate and then formic acid and acetic acid are successively extracted from the obtained mixture by fractionation.

EFFECT: method enables to obtain to commercial products - aromatic isophthalic acid and aliphatic formic acid and increases output of the end products.

3 cl, 1 dwg, 2 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing aromatic carboxylic acid. Said method involves an oxidative step for oxidising an alkyl aromatic compound in the presence of a bromine compound to obtain an aromatic carboxylic acid; and a step for burning exhaust gas formed at the oxidation step in an incinerator. The gas obtained after burning the exhaust gas at burning temperature ranging from 450°C to 1000°C is cooled to 250°C or lower, and the time for cooling from 450°C to 250°C in the cooling process is not more than 1 second.

EFFECT: use of the present method enables to inhibit formation of bromine-containing dioxins.

11 cl, 1 tbl, 4 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing and purifying isophthalic acid, involving step-by-step oxidation of m-substituted alkylbenzenes with atmospheric oxygen in acetic acid in the presence of a Co-Mn-Br catalyst at high temperature and pressure, followed by purification of the formed isophthalic acid via recrystallisation, wherein pure isophthalic acid is obtained via oxidation of m-xylene (or m-cymene) in two steps in narrow ranges of parameters on the steps (1, 2): T, °C - 191-194/194-195, with total concentration of Co and Mn - 800-1200 ppm, ratio Co:Mn=2.1-3.0:1, concentration of [H2O] in oxidation zones - 3.8-7.0/3.2-6.0 wt %, [O2] in spent O2 gas 2-4-5 vol. % and within 30-50 minutes, [m-KBA]=0.015-0.025% colour index ≤18°H is achieved in oxidation products, after which the extracted high-quality isophthalic acid is purified by recrystallising in water at temperature 170-225°C, and if said [m-KBA] and colour index are exceeded in high output conditions by increasing the load of m-xylene, the purification process is combined with hydrogenation of impurities on a composite catalyst consisting of Ru and Pd in weight ratio Ru:Pd=1:0.25-1.5 with total concentration [Ru+Pd]=0.5 wt %, in porous material based on a carbon support, activated carbon or a graphite-like material with total pore volume 0.6-0.8 cm3/g, and hydrogenation is carried out for 36-60 minutes at 170-225 °C.

EFFECT: high efficiency of production and purification, simple process.

2 cl, 1 dwg, 1 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing crude terephthalic acid for use at a hydrogenation purification step via liquid-phase oxidation with an oxygen-containing gas in an oxidation reactor fitted with a mixer, using as the starting material para-xylene in a solvent - acetic acid, in the presence of a metal-containing catalyst which contains cobalt (Co), manganese (Mn) and bromine (Br) as an oxidation promoter, where the oxidation reaction temperature is controlled such that is lies in the interval from 185 to 197°C, average dwell time of the starting mixture in the reactor for liquid-phase oxidation ranges from 0.7 to 1.5 hours, content of water in the reaction solvent is controlled such that it ranges from 8 to 15 wt %, and the composition of the catalyst in the solvent is controlled in a range defined depending on the reaction temperature such that it includes: (1) a catalytically active metal (Co+Mn) in amount of 2650 ppm or less and in amount equal to or more than a value determined by the following relationship: (Co+Mn) = -0.460(t-185)3+18.4(t-185)2-277.5(t-185)+2065, in which (Co+Mn) is the content of (Co+Mn) in ppm, t is the reaction temperature (°C) (temperature range from 185 to 200°C), (2) weight ratio Mn/Co is controlled in a range from 0.2 to 1.5, preferably from 0.2 to 1; (3) content of Br is equal to or less than 1.7, if represented by a value Br/(Co+Mn) in form of weight ratio, and in amount equal to or greater than a value given by the equation: Br/Mn = -0.00115(t-185)3+0.0362(t-185)2-0.5803(t-185)+5.18, in which Br/Mn is weight ratio Br/Mn (wt/wt), and t is reaction temperature (°C) (temperature range from 185 to 200°C), and crude terephthalic acid is obtained with content of 4-carboxybenzaldehyde in amount from 2000 to 3500 ppm as an intermediate product of liquid-phase oxidation. The method provides cheap production of crude terephthalic acid for use in hydrogenation purification and use of a controlled amount of oxidation catalyst, which does not have undesirable effect on the life of a hydrogenation purification catalyst, as well as conditions for carrying out the corresponding reaction.

EFFECT: obtaining terephthalic acid during liquid-phase oxidation of the corresponding dialkylated aromatic hydrocarbon using a solvent, acetic acid, carried out by reducing the oxidised amount of acetic acid lost during oxidation, limiting formation of ash in the obtained terephthalic acid, and enabling control of the composition of the oxidation catalyst depending on reaction temperature.

12 tbl, 7 dwg, 15 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing a composition of aromatic dicarboxylic acid, involving (a) oxidation of a multiphase reaction medium in a primary oxidation reactor to obtain a first suspension; (b) further oxidation of at least a portion of said first suspension in a secondary oxidation reactor which is of the bubble column type, wherein the method further involves feeding an aromatic compound into said primary oxidation reactor, where at least about 80 wt % of said aromatic compound fed into said primary oxidation reactor is oxidised therein, wherein head gases are moved from the top of the secondary oxidation reactor into the primary oxidation reactor. Disclosed are an optimised process and equipment for more efficient and cheaper liquid-phase oxidation. Such liquid-phase oxidation is carried out in a bubble column type reactor which ensures a highly efficient reaction at relatively low temperatures. When the oxidised compound is para-xylene and the oxidation reaction product is crude terephthalic acid (TPA), such a product, TPA, can e purified and extracted using cheaper methods than when TPA is obtained using the conventional high-temperature oxidation process.

EFFECT: improved method of producing a composition of aromatic dicarboxylic acid.

30 cl, 4 tbl, 31 dwg

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