Method of production of methacrylic acids by catalytic oxidation of propylene or isobutylene (versions), method of decomposition of by-product (versions) and plant for realization of this method

FIELD: industrial production of methacrylic acids at reduced amount of industrial wastes.

SUBSTANCE: proposed method is performed by catalytic oxidation of propane, propylene or isobutylene in vapor phase at separation of final product and forming of high-boiling mixture as by-product which contains (according to Michaels addition) water, alcohol or methacrylic acid added to methacrylic group. By-product is decomposed in thermal decomposition reactor at simultaneous distillation of decomposition products in distilling column from which methacrylic acid is taken in form of distillate. Flow of liquid decomposition residue is forced for peripheral direction by means of mixing blades before withdrawal from reactor. Peripheral direction is obtained with the aid of liquid fed from the outside of decomposition reactor; to this end use is made of initial high-boiling material or flow of liquid discharged from decomposition reactor. If necessary, etherification stage is performed through interaction with alcohol for obtaining methecrylic ester. Decomposition of by-product formed at obtaining methacrylic acid by oxidation of propylene or isobutylene or at obtaining methacrylic acid by interaction of acid with alcohol by alcohol through introduction of by-product into thermal decomposition reactor provided with distilling column which has plates made in form of disks and toroids for simultaneous decomposition and distillation. Plant proposed for realization of this method includes thermal decomposition reactor and distilling column, level meters and lines for discharge of liquid containing easily polymerized compounds. Level indicator mounted at area of accumulation of liquid shows pressure differential. Line for detecting the side of high pressure of this level meter is connected with accumulated liquid discharge line.

EFFECT: updated technology; increased yield of target products.

38 cl, 14 dwg, 2 tbl, ex

 

The technical FIELD

This invention relates to advantageous for the industrial production method for producing a (meth)acrylic acid at a high speed extraction by reducing the amount of industrial waste through decomposition by-products, such as the addition products according to Michael (meth)acrylic acid or meth(acrylic) ester, formed as by-products in the stage of obtaining a (meth)acrylic acids, and extraction of various compounds such as (meth)acrylic acid, esters of (meth)acrylic acid and alcohols.

In this description, the term "(meth)acrylic acid" is a General term for acrylic acid and methacrylic acid, and can mean either one, or both of them. Hereinafter, the term "(meth)acrylic acid" is a generic term for these acids and esters of (meth)acrylic acids derived from such acids and alcohols, and this term means containing at least one of these compounds.

The level of technology

A. As a method of decomposition of the reaction products of the accession of Michael, formed as by-products during receiving of acrylic acid or esters of acrylic acid, typically use a method of thermal decomposition without the use of catalyst in the case of the method of producing acrylic acid (JP-A-11-12222), whereas in the case of the procedure of obtaining the acrylic ester is known decomposition when heated in the presence of a Lewis acid or base Lewis (the Japan patent JP-A-49-55614, JP-B-7-68168, JP-A-9-110791, JP-A-9-124552, JP-A-10-45670). Further, as a reactive system decomposition products join Michael usually use reactive distillation, in which the desired decomposed product of the reaction is distilled off by distillation during the reaction of decomposition. Further, there is also known a method in which the addition products of the reaction of Michael, formed as by-products at the stage of obtaining acrylic acid, and addition products of the reaction of Michael, formed as by-products at the stage of obtaining the acrylic ester, unite together, followed by thermal decomposition. The known method of thermal decomposition using reactive distillation systems in the absence of any catalyst (JP-A-8-225486) and the method of decomposition with the use of highly concentrated acid catalyst (JP-A-9-183753).

To increase the speed of extraction of acrylic acid, ester of acrylic acid or alcohol that is used as a product or as a starting material for the reaction, in the upper part of this column decomposition reactions, it is necessary to increase the temperature of the decomposition reaction and to reduce the amount of discharge from the lower part, which still existed the problem lies in the fact that the liquid bottom is part tends to be Silvashi fluid; when the decomposition temperature is high, is formed, probably, oligomer or polymer of acrylic acid or acrylic ester, which leggopoker.com substance; and some of the substances contained in the source material for this reaction, tend to be precipitated, whereby at the bottom of the column of the decomposition reaction will be to Deposit the solids formed polymer due to the presence of liquid contained in the sediment (sludge), and such sediment will flow in the discharge line of the liquid; and, therefore, was not the right way through which the column of the decomposition reaction can be run continuously for a long time. Mainly in the case when the solid is accumulated in the lower part of the column of the decomposition reaction, easily curable liquid absorbed in deferred solid substance that has a tendency to be extremely curable, because it cannot flow, and the temperature of the decomposition reaction is relatively high, which leads hence to the phenomenon, when the amount of sludge will increase even more when such polymerization. Thus, it is desirable to solve the problem.

b. As an example of solving this problem is possible the way in which the diameter of the pipeline to transfer fluid the lower part of the smart is the culprit for transferring fluid at a high flow rate, but it was impossible to use this method, because the pump for such transfer must be type high-pressure pump, which is economically disadvantageous for industrial method of obtaining. Further, it is possible to use also the way in which to reduce the viscosity of the liquid, the lower part can be added to the return fluid from the stage or can be added to water again, but this will lead to a reduction in temperature of the liquid, whereby the clogging tends to slightly accelerate or to require the addition of such water in large quantities. Thus, the use of this method is practical impossible.

C. on the other hand, as is well known, there is a way of oxidation in the vapor phase propylene as the formation of acrylic acid. For such a method of producing acrylic acid by oxidation of propylene has a two-stage oxidation method in which the oxidation to acrolein and the next stage of oxidation to acrylic acid is carried out in separate reactors, respectively, as the conditions of oxidation are different, and the way in which oxidation to acrylic acid is carried out directly with the one-stage oxidation.

Fig.9 shows an example of a scheme for the formation of acrylic acid by two-stage oxidation with posleduyuschiey with alcohol with the formation of ester of acrylic acid. Namely, propylene, steam and air are subjected to two-stage oxidation using the first and second reactors filled with, for example, a catalyst of the type molybdenum, to form a gas containing acrylic acid. This contains acrylic acid gas is put into contact with water in the collecting column with obtaining an aqueous solution of acrylic acid, which is extracted in the extraction column by adding a suitable extracting solvent, and then extracting the solvent is separated in the column for separation of the solvent. Then acetic acid is separated in the column for the separation of acetic acid with obtaining crude acrylic acid, and in the fractionation column from this crude acrylic acid is separated by-product to obtain a purified product of acrylic acid. Further, this acrylic acid (purified product) etherification in the column of the esterification reaction and then using extraction columns and column separation lightweight component get the crude ester of acrylic acid. From this crude ester of acrylic acid is separated by-product (high-boiling product) in a fractionation column to obtain a purified product of an ester of acrylic acid.

Here, depending on the type of acrylic ester may be the case the th, in which technological scheme will be such as shown in figure 10. In this case, a by-product obtained as residue (ledogorov) in the column separation of acrylic acid.

In the method of producing acrylic ester figure 10 acrylic acid, alcohol, extracted acrylic acid and extracted alcohol is served, respectively, in the reactor for esterification. This esterification reactor filled with a catalyst, such as a strongly acidic ion-exchange resin. A mixture of the esterification reaction, containing educated ether, unreacted acrylic acid, unreacted alcohol, water formed, etc. allocated from this reactor, is fed into the column separation of acrylic acid.

From the bottom of this column for the separation of acrylic acid liquid, the lower part containing unreacted acrylic acid, divert and recycle to the reactor for esterification. Part of the liquid bottom served in the column separating the high-boiling component, through which separate the high-boiling component from the bottom and it is served in a reactor for the decomposition of the high-boiling component, and disposed (not shown). The decomposition product containing the valuable substance formed by the decomposition will be recycled in the process. In this process, where recycle this product decomposition varies in is depending on the process conditions. High-boiling impurities such as polymers, will be discharged from the reactor for the decomposition of the high-boiling component output from this system.

From the top of this column separation of acrylic acid is distilled ester of acrylic acid, unreacted alcohol and water formed. A portion of this distillate recycle in the form of liquid phlegmy in the column separation of acrylic acid, and the remainder is fed into the extraction column.

In this extraction column to supply water for the extraction of alcohol. Water containing alcohol, resulting from the lower part, is fed into the column regeneration alcohol. Distilled alcohol is recycled to the reactor for esterification.

The crude ester of acrylic acid from the top of the extraction column is fed to the column compartment boiling components, and boiling material is removed from the upper part and recycle it in the process. In this process, where it recirculates varies depending on the process conditions. The crude ester of acrylic acid containing a remote low-boiling material will be fed to the column cleanup product ester of acrylic acid, whereby from the top there is obtained the ester of acrylic acid of high purity. The liquid in the lower part contains a large amount of acrylic acid and, therefore, recirc who can be encouraged in this process. In this process, where it recirculates varies depending on the process conditions.

Further, in recent years, instead of the method of extraction solvent, in which the extracting acrylic acid from the above-described aqueous solution of acrylic acid is conducted by way of the extraction solvent, spend way azeotropic separation, in which the distillation is carried out with the use of water and the azeotropic solvent, so that from the upper part of the column azeotropic separation distilled azeotropic mixture containing water and the azeotropic solvent, and from the lower part of the distilling acrylic acid.

Further, practically used is also the way in which acrylic acid is obtained by using propane instead of propylene and using a mixed oxide catalyst of the type Mo-V-Te or mixed oxide catalyst of the type Mo-V-Sb. In the case of methacrylic acid and methacrylic acid are used isobutylene or tert-butyl alcohol instead of propylene, and the purified product of methacrylic acid and the purified product of methacrylic acid get through a similar oxidation process and the subsequent process of esterification.

Further, as a method of forming ester of (meth)acrylic acid (ester of acrylic acid or methacrylic acid) used the method in which oterom ester of (meth)acrylic acid lower alcohol and the higher alcohol is subjected to interesterification reaction using, for example, acid as catalyst with obtaining ether (meth)acrylic acid higher alcohol. The crude ester of (meth)acrylic acid obtained by the interesterification reaction, is subjected to such stages as the catalyst separation, concentration and fractionation of obtaining a purified ether (meth)acrylic acid.

A useful by-product, such as product join Michael is contained in the fraction separated by distillation and purification of the above crude acrylic acid, the crude methacrylic acid, the crude ester of acrylic acid or crude methacrylic acid. Thus, this byproduct destroy for the regeneration of the (meth)acrylic acid or its ester or alcohol starting material.

To date, the methods described above in A. have been known as methods of decomposition joining Michael formed side while obtaining acrylic acid or acrylic ester. Thus, the first was a common decomposition product of joining Michael formed side while obtaining ester of acrylic acid, to regenerate through this valuable substances, such as acrylic acid, ester of acrylic acid or alcohol. As this method of decomposition and regeneration usually use the Lee system reactive (reactive) distillation in which the distillation is carried out when carrying out the decomposition reaction.

For system reactive distillation using a reactor equipped at the top of the distillation column. As such distillation columns are usually used with a plate column provided within the various plates or Packed column filled with a variety of supplementary materials for the occurrence of fractionation effects. These plates can be, for example, nozzle plates, single-threaded plates, flexible plates, ballast plates, perforated plates (sieve plates), extractor plates, covered with ripples plates, double-flow plates double or bubble plates. Supplementary material can be, for example, supplementary material type rings, such as ring process (contact material for Packed columns), spiral rings or metal Pall rings, or supplementary material saddle type, such as saddle-shaped head Burleigh for Packed columns or internal saddle, or other materials, such as nozzle Goodloe ring Dickson, saddle-shaped mesh nozzle MacMahon or vertically adjustable nozzle material nozzle type flat dish.

However, in both methods of obtaining acrylic acid and of acrylic ester starting material, which must be submitted at the stage of decomposition by-product, is the fraction obtained by the concentration of high boiling point component formed in the reaction system or cleaning system. In addition, acrylic acid and esters of acrylic acid are very easily curable materials and, therefore, the original product of the decomposition reaction contains the formed polymers. Further, the decomposition reaction is carried out at high temperature and, therefore, will produce the polymer during the decomposition reaction. Thus, it is likely that a solid substance is already present in the source material subject to decomposition, and even in the absence of solids in the source material it can Deposit again or solid substance may be formed during the operation of distillation separation or in the stage of decomposition, where at the same time carry out a chemical reaction. When this adhesion, deposition or accumulation of such solids have a place on plates or in free space of the Packed material in the distillation column, whereby, for example, be an increase in gauge pressure (pressure drop), the violation of the condition of the contact gas/liquid and additional blockage. Thus, there was a problem, which consists in the fact that su is it tends to impede the availability of high-speed extraction of valuable substances or to prevent a continuous mode of operation.

Thus, in both methods of obtaining acrylic acid and acrylic ester is desirable solution to the above challenges and the development of the method of decomposition joining Michael, through which can be continuously achieved high recovery rates.

d. Further, in the method of regeneration (meth)acrylic acid or ester of (meth)acrylic acid by carrying out the decomposition reaction of the reaction product attaching to Michael formed by side during the process of obtaining a (meth)acrylic acid or ester of (meth)acrylic acid, if the temperature of the decomposition reaction are doing high for high speed regeneration for such a (meth)acrylic acid ester (meth)acrylic acid or alcohol, will be formed oligomer or polymer of (meth)acrylic acid or ester of (meth)acrylic acid, which is easily curable substance. To prevent such polymerization assumes the addition of molecular oxygen, addition polymerization inhibitor such as hydroquinone, methoxyhydroquinone, phenothiazines or hydroxylamine, in the decomposition reactor (for example, the above-mentioned Japan patent JP-A-10-45670, paragraphs 0012 and 0019).

However, using this method may be the case that can be not only not received adequate action in respect of the prevention of polymerization of (meth)acrylic acid or ester of (meth)acrylic acid in the product decomposition by oxygen, but it can also accelerate the polymerization and, therefore, may be a case where the above-mentioned reaction of the decomposition may not continue for a long time.

E. Next, the gas containing acrylic acid obtained by catalytic oxidation in the vapor phase with molecular oxygen propylene and/or acrolein usually contains maleic acid as a side product in the amount of approximately 0.2 to 1.6 wt.% in the calculation of the acrylic acid. Maleic acid is a dicarboxylic acid represented by NASO-CH=CH-CO2N, and it is in equilibrium with the anhydride of the carboxylic acid with one molecule of water, digidratirovannogo in the molecule in the solution. Further, if there are no other indications, maleic acid and maleic anhydride will be called together maleic acid. When the gas containing acrylic acid, collecting the solvent in the form of a solution containing acrylic acid, at the same time will be collected maleic acid. The boiling point of maleic acid is high compared with the boiling point of acrylic acid and in the stage of purification by distillation of maleic acid is concentrated in the residues.

When the exposure of two molecules of acrylic acid accession Michael will be formed dimer is krylovii acid. Not there are ways to prevent the formation of such a dimer of acrylic acid in a solution of acrylic acid and the rate of formation increases as the temperature becomes high. Further, higher oligomer, such as the trimer of acrylic acid to be sequentially to form acrylic acid and dimer of acrylic acid. In the stage of purification of acrylic acid dimer (or oligomer) acrylic acid will be formed mainly in the distillation column, where they conduct heat, in particular in the lower part, where the temperature is high and the retention time is long.

To improve the speed of regeneration of acrylic acid at the stage of purification is usually regenerate acrylic acid formed from the oligomer acrylic acid.

As a method of regeneration of the oligomer acrylic acid can be used, for example, the way in which conduct thermal decomposition under reduced pressure in the presence or in the absence of catalyst and acrylic acid recovered in the form of distilled gas or distilled liquid, as described in Japan patent JP-B-45-19281. In this case, the distilled gas and the distilled liquid acrylic acid contains a large amount of high-boiling compounds, other than the recycled acrylic acid, is aka as maleic acid. When the temperature of operation increases to increase the speed of regeneration of acrylic acid, the concentration of maleic acid in the recycled acrylic acid will also increase.

As a way to reduce such maleic acid in the method described in Japan patent JP-A-11-12222, the crude acrylic acid containing 3 to 10 wt.% maleic acid and other oligomers of acrylic acid, injected into the column for regeneration of acrylic acid and acrylic acid is distilled from the top, and the liquid in the lower part of thermally decompose and such fluid the lower part of the recycle column regeneration, and the amount of maleic acid can be reduced to the level of 0-3 wt.%.

In this method of extraction by thermal decomposition of the oligomer of acrylic acid with maleic acid as an impurity take away in the form of precipitation devices for the reaction of thermal decomposition or distillation device. At this time, if the amount of maleic acid contained in the extracted acrylic acid is large, the amount of maleic acid, recircularize in this system will increase, whereby will increase the equipment and the heat load at this stage of treatment. The easiest way to prevent this is to reduce the quantity is of oligomer acrylic acid, removed by thermal decomposition, but the rate of extraction of acrylic acid at this stage of treatment is thereby reduced and it will get worse economic efficiency.

To improve the degree of extraction of acrylic acid and reduce the recirculating amount of maleic acid is there a way to add a distillation column as described in the method described in Japan patent JP-A-11-1222. However, since acrylic acid is leggopoker.com connection, usually conduct the distillation under reduced pressure to prevent polymerization by lowering the operating temperature, but since the boiling point of maleic acid is higher than the melting point of acrylic acid, even if the working pressure is reduced, the increase in the operating temperature cannot be eliminated. This will not only alleviate the clogging of the distillation device as a result of polymerization, but tends to accelerate the formation of oligomer of acrylic acid in the acrylic acid extracted by thermal decomposition. Further, to increase the degree of vacuum distillation diameter distillation column increases, as a result will also increase the load during construction and operation.

Next, a concentrated maleina the second acid is discharged from the bottom of the column. However, the maleic acid is a solid at room temperature and, therefore, there is a problem, which consists in the fact that the viscosity of this fluid tends to rise from the bottom to the bottom of the distillation column and is likely to lead to a deterioration of the ability of a separation due to contamination or deposition of polymer or obstruct.

Such problems are observed when maleic acid, which mixture is separated in the form of high-boiling substances by distillation.

In order to enable phase concentration of maleic acid by distillation and to improve the efficiency of extraction of acrylic acid by thermal decomposition, it is necessary to conduct without giving great heat, as by distillation, either (1) reducing the concentration of maleic acid in a solution of acrylic acid fed to the device for the reaction of thermal decomposition, or (2) the reduction of maleic acid in a solution of acrylic acid to be extracted from the device reaction of thermal decomposition.

f. Further, in the first device for producing acrylic acid or the like, it was common for measuring pressure by means of mounting the detecting portion of the high pressure side of the meter liquid level directly associated with the main what obosom installation. However, using the conventional method for mounting measuring the liquid level of the polymerization inhibitor to be used to obtain lignopolimering connection or formed polymer enters the detecting portion of the high pressure side of the gauge of level of a liquid and a solid substance should probably be accumulated, resulting in the observed erroneous operation of the gauge of level of a liquid, usually used for observation level.

Thus it is usually difficult to carry out accurate measurement continuously by measuring the liquid level, making it difficult to carry out continuous operation of such a facility for a long period of time.

Description of the INVENTION

A. The purpose of this invention is to overcome the problems in the conventional decomposition reaction product of the accession of Michael acrylic acid or acrylic ester, that by this not to give a deposition to remain in the column of the decomposition reaction, to prevent the formation of polymer in the column of the decomposition reaction and to prevent unexpected clogging of the pipeline discharge, so as to ensure stable operation.

b. Further, the purpose of this invention is the provision of a method of decomposition by-product during production (methacrylic acid, whereby during regeneration of valuable substances by decomposition via reactive distillation systems education product join Michael formed by side in the process of obtaining a (meth)acrylic acid or ester of (meth)acrylic acid, adhesion, deposition or accumulation of such solids are prevented, high speed retrieve (meth)acrylic acid ester (meth)acrylic acid and alcohol may be kept and may be held constant continuous operation over a long period of time.

C. Further, the purpose of this invention is the provision of a remedy recyclization maleic acid in the cleaning system of acrylic acid, providing thermal decomposition and removing the oligomer of acrylic acid at the stage of distillation purification, containing acrylic acid fluid, and easy cleanup without problems polymerization of acrylic acid or clogging of the equipment at this stage of treatment.

d. Further, the purpose of this invention is the provision of a method of installation of the meter liquid level on the unit to get lignopolimering connection through which can continuously be carried out accurate measurement, by preventing the formation and accumulation firmly what about the substance of the subject measured fluid detection part of the high pressure side of the meter liquid level.

The authors of this invention have conducted various studies to achieve the above objectives and as a result have complied with this invention, having the following main aspects.

(1) a method of obtaining a (meth)acrylic acid, which provides the decomposition in the decomposition reactor high-boiling mixtures formed as a by-product while obtaining (meth)acrylic acid, characterized in that the high-boiling product mixture contains joining Michael, containing water, alcohol or (meth)acrylic acid attached to (meth)acryloyloxy group; while through the compulsory giving of fluid flow in the peripheral direction of the liquid residue of the reaction in the reactor for the decomposition of this liquid residue of the reaction unload and remove the (meth)acrylic acid or ester of (meth)acrylic acid.

(2) the Method according to item (1), characterized in that the fluid flow in the peripheral direction is given mixing blades mounted in the reactor decay.

(3) the Method according to item (1), characterized in that the fluid flow in the peripheral direction is given by the liquid supplied from the outside of the reactor decay.

(4) the Method according to item (3), characterized in that the liquid supplied from the outside of the reactor decomposition is storable mater the scarlet served as source material, or return fluid liquid residue of the reaction, discharged from the decomposition reactor.

(5) the Method according to any of items (1)to(4), characterized in that the liquid residue of the reaction periodically discharged from the decomposition reactor.

(6) the Method according to any of items (1)to(5), characterized in that during the extraction of valuable substances by carrying out distillation and thermal decomposition of high-boiling mixture, the distillation is carried out with the use of a distillation column which is provided with an inside plates of the type disks and toroids.

(7) the Method according to any of items (1)to(6), characterized in that the distillate from the reactor decomposition of added oxygen-containing gas.

(8) the Method according to any of items (1)to(7), characterized in that the liquid to be added to the reactor thermal decomposition, or from the liquid extracted from the reactor thermal decomposition, precipitated and separated maleic acid contained in the specified fluid.

(9) the Method according to any of (1)to(8), characterized in that the reactor thermal decomposition of the installed meter liquid level and line detection the high pressure side of the meter liquid level is connected to the discharge line of the liquid reactor decay.

This invention has the following preferred options (the)-(f).

A1. A method of obtaining a (meth)acrylic acid, which is a way of obtaining acrylic acid or (meth)acrylic acid (called hereinafter referred to in General as well as (meth)acrylic acid) or ester (meth)acrylic acid ((meth)acrylic acid and an ester of (meth)acrylic acid can be called forth in the General form of (meth)acrylic acids), through phase reactions involving catalytic oxidation in the vapor phase propylene, propane or isobutylene, and then, if necessary, the reaction involving the stage of esterification, characterized in that at that time, when the high-boiling mixture (hereinafter referred to as the high-boiling material)containing the product of the joining Michael decomposed in the reactor, decomposition for extraction of (meth)acrylic acids, liquid balance this reaction is discharged through the compulsory giving of fluid flow in the peripheral direction of this liquid residue of the reaction in the reactor decay.

A2. The method according to item A1, where the flow of the fluid in the peripheral direction is given mixing blades mounted in the reactor decay.

A3. The way the points A1 or A2, where the mixing blades are anchor blade, multi-blade blades, multi-inclined impeller blades or lattice the blades.

A4. The method according to A1 or A2, where the design of the stirring blades is such that on rotation of the rod, installed vertically in the Central part of the reactor, radial flow-type blades attached in two or more steps in the direction of the axis of rotation, so that the blades are adjacent in the direction of the axis of rotation toward the direction of the axis of rotation so that their phases are offset from each other by no more than 90aboutand the lower part of one of the blades of the upper-stage neighboring in the direction of the axis of rotation is located below the highest part of the blade bottom step.

A5. The method according to A1, where the flow of the fluid in the peripheral direction is given by the liquid supplied from the outside of the reactor decay.

A6. The method according to A1 or A5, where the liquid is supplied from the outside of the reactor decay, is a high-boiling material, supplied as source material, or return fluid liquid residue of the reaction, discharged from the decomposition reactor.

b1. A method of obtaining a (meth)acrylic acid, which is a way of obtaining acrylic acid, (meth)acrylic acid or ester of (meth)acrylic acid by the reaction involving the catalytic oxidation in the vapor phase propylene, propane or isobutylene, and then, if the need the reaction involving the stage of esterification, characterized in that at a time when high-boiling mixture (hereinafter referred to as the high-boiling material)containing the product of the joining Michael decomposed in the reactor, decomposition for extraction of (meth)acrylic acid, a liquid residue of the reaction periodically discharged from the decomposition reactor.

b2. The method according to item b1, where the stop time of the discharge is from 5 sec to 5 min and unloading time is from 2 seconds to 5 minutes

b3. The way the points b1 and b2, where the liquid high-boiling material is continuously fed into the reactor decay and (meth)acrylic acid is continuously discharged from the vapor phase.

C1. In the process, which provides for the introduction of by-product formed during retrieval (meth)acrylic acid and/or by-product formed during retrieval ether (meth)acrylic acid in a reactor equipped with a distillation column, for thermal decomposition of by-product and simultaneous distillation for recovery of valuable substances, the method of decomposition by-product formed during retrieval (meth)acrylic acid, characterized in that, as specified distillation columns use the distillation column, which is provided inside the plates of the type disks and toroids.

C2. The method according to item C1, where by-product formed during retrieval (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining (meth)acrylic acid as a by-product formed during retrieval ether (meth)acrylic acid is a liquid, the lower part of the fractionation column for the separation of high-boiling fractions of the stage of purification of the ester (meth)acrylic acid.

C3. The method according to C1 or C2, where a by-product formed during retrieval (meth)acrylic acid, and/or by-product formed during retrieval ether (meth)acrylic acid, contains the product of the joining Michael, containing water, alcohol or (meth)acrylic acid attached to (meth)acryloyloxy group.

C4. The method according to any of the C1-C3, where the reaction temperature of thermal decomposition is equal 120-280aboutC and reaction time of thermal decomposition is from 0.5 to 50 hours.

d1. The method of decomposition by-product formed during retrieval (meth)acrylic acid, involving the decomposition in the decomposition reactor byproduct formed during retrieval (meth)acrylic acid and/or by-product formed during retrieval ether (meth)acrylic acid, and distillation of the decomposed product of the decomposition reactor, the tives such as those to the distillate from the reactor decomposition of added oxygen-containing gas.

d2. The method according to d1, where by-product formed during retrieval (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining (meth)acrylic acid as a by-product formed during retrieval ether (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining ether (meth)acrylic acid or precipitation columns for the separation of (meth)acrylic acid.

d3. The method according to d1 or d2, where by-product, which must be decomposed, contains the product of the joining Michael.

d4. The method according to any of d1-d3, where the gas containing oxygen is air or oxygen diluted with an inert gas.

d5. The method according to any of d1-d4, where the gas containing oxygen is added to the discharge line for distillate from the reactor decomposition or in the upper part of the reactor decay.

E1. In the production method of acrylic acid, which provides the interaction with the solvent containing the acrylic acid gas obtained by the catalytic oxidation of propane or propylene, for collecting the acrylic acid in the form containing acrylic acid solution and purification of acrylic acid by distillation obtained containing acrylic acid R is the target, the method of extraction of acrylic acid, characterized in that the residues obtained from the lower part of the fractionation column to acrylic acid, or a liquid obtained by heating and concentration of such residue, served in the reactor for thermal decomposition for the decomposition of the oligomer of acrylic acid in the liquid and the obtained acrylic acid is extracted at the stage of purification in which the liquid fed to the reactor for thermal decomposition, or from the liquid extracted from the reactor for thermal decomposition, precipitated and separated maleic acid contained in the liquid.

E2. The method according to E1, where the composition of the liquid fed to the reactor thermal decomposition, or liquid extracted from the reactor thermal decomposition adjusted to obtain a solution containing at least 70 wt.% acrylic acid, 1,6-28 wt.% maleic acid and/or maleic anhydride and water, having a molar ratio:

Water

--------------------------(molar ratio) is less than or equal to 1.0

maleic acid+

maleic anhydride x 2

and maleic acid precipitated at 20-70aboutWith in the range of 0.5-5 hours, followed by filtration and separation.

E3. The method according to E1 or E2, where during the operation of the Department of maleic acid type aliphatic or aromatic hydrocarbon 0.5-4-cu is coherent volume.

E4. The method according to E3, where the added hydrocarbon solvent is to be used for collection containing acrylic acid gas, or azeotropic agent that should be used for dehydration distillation purification of acrylic acid.

f1. Method of establishing meter liquid level when measuring liquid level set in the place where fluid accumulates containing lignopolimering connection, installing obtain lignopolimering connection, characterized in that the line detection the high pressure side of the meter liquid level is connected with a discharge line for the collected liquid.

f2. The method according to f1, where the angle of attach α between line detection of the high-pressure side and the line of discharge of the liquid is 5-90about.

f3. The method according to f1, where the ratio of the size of D2/D1is 1-20, where D1is the diameter of the pipe line detection of the high-pressure side, and D2is the diameter of the pipe line discharging liquid.

f4. The method according to f1, where the line of discharge of the liquid attached to the distillation column, the reservoir return phlegmy distillation columns, the column of the decomposition reaction, film evaporator, reservoir fluid from condensed gas the top of the column, vertical storage tanks, horizontal storage tank or cistern.

f5. The method according to any of the f1-f4, where the line detection of the high-pressure side and/or the detection of the low pressure level meter fluid is heated or is heated.

f6. The method according to any of the f1-f5, where the line detection of the high-pressure side and/or the detection of the low pressure level meter fluid connected to the inlet opening for a gas and/or liquid.

f7. The method according to any of the f1-f6, where lignopolimering compound is (meth)acrylic acid or its ester and the liquid being measured by the level meter fluid comprises at least one compound selected from a dimer of acrylic acid, esters β-(meth)aryloxypropanolamine acid, esters β-alkoxyamino acid, β-hydroxypropionic acid and esters β-hydroxypropionic acid.

BRIEF DESCRIPTION of FIGURES

Figure 1 shows an example of the line receiving means of the reaction of thermal decomposition (spiral is formed over the liquid returned to the reactor decomposition).

Figure 2 shows an example of the line receiving means of the reaction of thermal decomposition (spiral formed within the liquid source material fed to the reactor RA the situation).

Figure 3 shows an example of the line receiving means of the reaction of thermal decomposition (spiral formed during mixing blades).

Figure 4 is a view showing a view in cross-section in the horizontal direction of the reactor And decay and the positional relationship for the connection with these lines for the formation of spiral flow.

Figure 5 is a view schematically showing a solid substance, nakaplivavshiesya at the bottom of the reactor And decomposition (view in cross-section in the longitudinal direction of the column).

6 shows an example of the line receiving means of the reaction of thermal decomposition.

Fig.7(a) is a schematic view in cross section showing the distillation column equipped with a flat plate disks and toroids, suitable for carrying out the method of decomposition by-product formed during retrieval (meth)acrylic acid in accordance with this invention.

Fig.7(b) is an enlarged perspective view of main parts Fig.7(a).

Fig(a) is a schematic view in cross section showing the distillation column provided with a beveled plate disks and toroids, suitable for carrying out the method of decomposition by-product formed during retrieval (meth)acrylic acid is accordance with this invention.

Fig(b) is an enlarged perspective view of main parts Fig(a).

Figure 9 is an example schematic of obtaining acrylic acid and acrylic ester.

Figure 10 is another example of the arrangement of receipt of the acrylic ester.

11 is a diagram of the decomposition of the high-boiling liquid.

Fig is a view showing the whole setup, where the way of establishing the level meter fluid of the present invention applied to a column of the decomposition reaction (high boiling material) and the upper tank of gas-cooled fluid in obtaining acrylic acid.

Fig is a partial enlarged view showing the gauge of level of a liquid, mounted on the column of the decomposition reaction (high boiling material) 11.

Fig is a partial enlarged view showing the gauge of level of a liquid, mounted on the column of the decomposition reaction (high boiling material) 11.

Explanation of reference symbols

A: the decomposition Reactor

In: the lower Pump part

With: a heat Exchanger for heating

D: Mixing tool

E: Deposition

F: Valve control periodic unloading

1: the supply Line of the high-boiling material

2: the Line of discharge of the liquid bottom

2-1, 2-2: Line discharging residual liquid

3: the supply Line to the heat exchanger of the La heat

3-2: the return Line for heating

4: Line unloading balance reactions

5: return Line, forming a spiral flow.

6: Line regeneration extraction of valuable substances

7: supply Line fluid

8: production Line of coolant

31, 33: Distillation columns

31D, 33D: Orifice discharge residue

32A, 34A: Disc plates

32V, 34B: Toroidal plates

35: Switchgear

41: Column decomposition reaction

42, 46: Pumps

43: a heat Exchanger for heating

44a: gas Pipeline upper part of the column

44, 47 Heat

45: Tank with chilled liquid

6A: Column decomposition reaction (high boiling material)

6TH: a Tank of gas-cooled fluid to the upper part of the column

H1N2: gauges liquid level

62: Line discharging liquid bottom

A: Short pipeline discharging liquid bottom

62b: Pipeline discharging liquid bottom

65: Line discharging liquid bottom

65A: Short pipeline discharging liquid bottom

65b: Pipeline discharging liquid bottom

11, 13: Line detection of the high-pressure side

11a, 13A: Short pipelines detecting the high pressure side

11b, 13b: Pipelines detection part of high pressure to the I

12, 14: Line detection of the low pressure

12A, 14a: Short pipelines detection of the low pressure

12b, 14b: Pipelines detection of the low pressure

α: the connection Angle between the center line of the detection of the high-pressure side and a discharge line fluid

The BEST OPTION of carrying out the INVENTION

Option a

This option has been made on the basis of detection of the fact that in the decomposition reaction product of the joining of Michael acrylic acid or acrylic ester is very effective is the implementation of fluid flow in the lower part of the column in the peripheral direction to prevent the accumulation of solids in the lower part of the column for the decomposition reaction and thereby eliminate polymerization as a result of such accumulation.

1. (Meth)acrylic acid and an ester of (meth)acrylic acid

This invention can be applied to handle the decomposition of the high-boiling mixture (high boiling material)obtained while obtaining (meth)acrylic acid or ester of (meth)acrylic acid. For example, it can be applied to a method for producing (meth)acrylic acid by catalytic oxidation in the vapor phase propylene or isobutylene in the presence of a mixed oxide of the type Mo-Bi in cachestatistics education acrolein or methacrolein followed by catalytic oxidation in the vapor phase in the presence of a mixed oxide of the type Mo-V as a catalyst. In this case, the preliminary reaction with the formation of acrolein or methacrolein oxidation of propylene or the like, and a later reaction with the formation of mainly (meth)acrylic acid by oxidation of acrolein or methacrolein may be conducted in separate reactors, respectively, or such reaction can be carried out in one reactor, filled as the catalyst prior to the reaction, and the catalyst for later reactions. Further, this invention is applicable also to a method for producing acrylic acid by oxidation in the vapor phase propane using a mixed oxide of the type Mo-V-Te as a catalyst or a complex oxide of the type Mo-V-Sb as a catalyst. Further, it is applicable also to a method for producing ester of acrylic acid by the reaction of an alcohol with (meth)acrylic acid.

The high-boiling mixture (high boiling material)obtained after separation of the desired product in these ways, is also subject to decomposition with the use of this invention. As the acrylic ester can be mentioned With1-8-alkilany or cycloalkenyl ether. For example, there can be mentioned methyl acrylate, acrylate, butyl acrylate, isobutylamine, tert-butyl acrylate, 2-ethyl hexyl acrylate, 2-hydroxyethylacrylate, 2-hydroxypropylmethacrylate or methoxyethylamine. In relation to e the Ira (meth)acrylic acid can be mentioned ethers, similar to the above-mentioned esters.

Product joining Michael

Product joining Michael is contained in the high boiling material, as subject to decomposition object of this invention is a product having a combination of active hydrogen, such as water, alcohol or (meth)acrylic acid attached in the form of an ion to the double bond carbon-carbon (meth)acrylic acid or ester of (meth)acrylic acid. Specifically, the product of the joining Michael in the case of obtaining acrylic acid can be, for example, a dimer of acrylic acid (hereinafter referred to as dimer, trimer of acrylic acid (hereinafter referred to as trimer, tetramer of acrylic acid (hereinafter referred to as a tetramer) or β-oeprational acid, as shown below.

Dimer: N2C=CH-C(=O)-O-CH2-CH2-C(=O)-HE

The trimer: N2C=CH-C(=O)-O-CH2-CH2-C(=O)-CH2-CH2-C(=O)-HE

The tetramer: N2C=CH-C(=O)-O-CH2-CH2-C(=O)-CH2-CH2-C(=O)-O-CH2-CH2-C(=O)-HE

β-oxopropionate acid: BUT-CH2-CH2-C(=O)-HE

On the other hand, the product of the joining Michael in the case of obtaining the acrylic ester can be, for example, the product of the accession of Michael acrylic acid to the above-mentioned ether, acrylic acid, in particular, ether β -aryloxypropanolamine acid (ether dimer); the product of the joining Michael alcohol, in particular an ester of the dimer, trimer or tetramer, β-oxopropanoic acid, esters β-oxopropanoic acid or esters β-acceptability acid.

Ether β-aryloxypropanolamine acid: H2C=CH-C(=O)-O-CH2-CH2-C(=O)-OR

Ether β-alkoxyamino acid: RO-CH2-CH2-C(=O)-OR

Ester trimer: N2C=CH-C(=O)-O-CH2-CH2-C(=O)-O-CH2-CH2-C(=O)-OR

Ether β-oxopropanoic acid: BUT-CH2-CH2-C(=O)-OR

β-oxopropionate acid: BUT-CH2-CH2-C(=O)-HE

As for methacrylic acid and methacrylic acid, also use essentially the same as described above. The only difference is that the replacement of the hydrogen in position α methyl group propionic acid (ester) becomes somaclonal acid (ester).

High-boiling material, which should be supplied to the decomposition reactor is a high boiling point mixture containing the above-described product join Michael. Product content join Michael can vary greatly depending on the method of obtaining. However, the General is the use of high-boiling material, terasawa product joining Michael in the amount of 1-90 wt.%, preferably 2-70 wt.%. This high boiling material contains a compound formed by side on the stage of obtaining a (meth)acrylic acid, or a substance that should be used as an auxiliary agent in this way. Specifically, there may be mentioned, for example, (meth)acrylic acid, esters of (meth)acrylic acid, maleic acid, esters of maleic acid, furfural, benzaldehyde, polymers, oligomers, alcohols, used as materials for producing esters, or polymerization inhibitors, in particular acrylate copper, dithiocarbamate copper connection (derived) phenol or a compound (derivative) fenotiazina.

Dithiocarbamate copper can be, for example, dialkyldithiocarbamato copper, such as copper dimethyldithiocarbamate, copper diethyldithiocarbamate, dipropylthiocarbamate copper or dibutyldithiocarbamate copper, cyclic alkylenediamines copper, such as atlantajournal copper, tetramethylthiuram copper, pentametilenditiokarbamata copper or hexamethylenediisocyanate copper, or cyclic oxyvalerianate copper, such as occipitocervical copper.

The connection of the phenol may be hydroquinone, methoxyhydroquinone (methoxyimino), pyragollole, resorcinol, phenol or cresol. Connection fenotiazina may be, for example, the dryer is diazinon, bis(α-methylbenzyl)phenothiazines, 3,7-doctrination or bis(α-dimethylbenzyl)phenothiazines. In some cases, may contain substances other than those mentioned above, depending on the process without adversely affecting the invention.

A method of obtaining a (meth)acrylic acids

The above high-boiling material may be, for example, obtained through the stages of purification such as extraction or distillation, after contacting containing (meth)acrylic acid gas obtained by the catalytic oxidation in the vapor phase propylene or acrolein, with water or an organic solvent for collecting (meth)acrylic acid in the form of a solution. The method of producing ether (meth)acrylic acid includes, for example, the stage of the esterification reaction of interaction of (meth)acrylic acid with an alcohol in the presence of an organic acid or a cation exchange resin or the like, as a catalyst, and the stage of cleaning, carrying out extraction, evaporation or distillation as a single operation for the concentration of a solution of the crude ester of (meth)acrylic acid obtained by this reaction. Each such operation is chosen appropriately depending on the ratio of the (meth)acrylic acid and alcohol starting material in this esterification reaction, the type of catalyst used is used for the esterification reaction, or physical properties of starting materials, side reaction products, etc.

The reaction scheme for thermal decomposition of high boiling material

The description will use links on the graphic illustrations. Figure 1 is an example of line retrieve (continuous line) using the reaction of thermal decomposition of this invention. High-boiling material is served by line 1 into the reactor And decay. The feed to the reactor And the decomposition can be carried out continuously or periodically (semi-continuous), but preferred is a continuous flow. Valuable substance, formed in the decomposition reactor, and part of the materials comprising the high-boiling material will be continuously discharged in a gaseous state line extraction 6 and will return to this production process as it is in a gaseous state, or by cooling in a liquid state. When the decomposition reactor And the reactor is of the type column, part of the cooled fluid may be returned in the form of liquid phlegmy in the upper part of the reactor decay.

The residual liquid will be discharged through line 2 discharging residual liquid in the pump At the bottom and part of it is fed to the heat exchanger for heating using lines 3 and is returned to the reactor decomposition of A. the Remainder will be discharged from the system through line 4. The ratio between the amount of returned fluid and the amount of discharge can be appropriately set depending on various factors such as the heat balance in the heat exchanger for heating and retention time in the reactor decay. Over in the peripheral direction (hereinafter sometimes referred to as spiral flow) in the decomposition reactor of the present invention is formed of the return fluid line 5 in figure 1. Line 5 is located in a tangential direction relative to the main body of the reactor, decomposition, and spiral course be formed in the reactor by the flow of liquid is supplied from line 5. The number of returned fluid line 5 is usually chosen in the 0.2-to 5-fold range by weight based on the amount of starting material fed from line 1. If the number of returned fluid is less than the above range, it is hardly formed adequate spiral course. The liquid is returned to the heat flowing through the line 3-2, is not associated with the formation of spiral flow and its velocity is determined depending on, for example, from thermal equilibrium.

Figure 2 is an example in which the flow in the peripheral direction is performed by the liquid source material supplied to the decomposition reactor and the liquid is conducted by line 1. INIA 1 is located in a tangential direction relative to the main body of the reactor, decomposition, and spiral course be formed in the reactor liquid is supplied from the line 1. In this case, line 1 should be regulated so that the surface of this liquid was below the surface of the reaction liquid held in the reactor for the decomposition.

Figure 3 is an example of a device for the formation of spiral flow in the reactor decomposition using stirring blades.

High-boiling material is fed through line 1 into reactor decomposition of A. Valuable substance and part of the materials comprising the high-boiling material is decomposed in the decomposition reactor And will be allocated on line retrieve 6 and will be back in the flow of the process of obtaining as-is in a gaseous state, or when they are cooled in a liquid state. When the decomposition reactor And the reactor is of the type column, part of the cooled fluid may be returned in the form of liquid phlegmy in the upper part of the decomposition reactor. The residual liquid will be discharged from line 4 from this system. Line 7 supply and line 8 release coolant are approximate and depending on the type of coolant, the provisions of the supply line and the discharge line can be changed.

Over in the peripheral direction (spiral) in this decomposition reactor of the present invention is plumage is asiausa means D residual liquid figure 3. Mixing means D includes a mixing blade (scapula), stirring rod and a motor for mixing, whereby the internal fluid of the reactor decay can form a fluid flow in the peripheral direction. Rotational speed of the stirring blades is usually chosen appropriately depending on the shape or diameter of the blades so that the velocity of the leading edge of the blades is typically equal to 0.2-5 m/sec. Residual liquid, forming a spiral flow will be diverted through line 2-1 or 2-2 discharging residual liquid. Line 2-1 discharging residual liquid is an example in which it is located in the tangential direction (tangent) of the main body of reactor decay, and the line 2-2 shows an example in which it is located in the Central part of the decomposition reactor. In the case of line unloading 2-1 together with the mixing action of the blades may be supported by a good spiral flow.

Figure 4 is a view showing a cross-section of the reactor decomposition of A. Line 5 (the return line 5, forming a spiral flow) of figure 1 or line 1 (line 1 the submission of high-boiling material) in figure 2 are arranged in the tangential direction relative to the main body of the decomposition reactor, whereby the reactor razloga the Oia may be formed over the peripheral direction (spiral). Next, line 2-1 discharging residual liquid figure 3 is located in a tangential direction relative to the main body of the decomposition reactor, whereby together with the mixing action of the blades may be supported by a good spiral flow.

Figure 5 is a view (a view in longitudinal cross-section of the column), schematically showing the solids accumulated in the bottom of the reactor decomposition of A. If the left and right accumulated products incorporate, holes for unloading will be in the blocked state, resulting in the removal of the fluid lower part will fail and the pump In the lower part may be subjected to cavitation.

The reaction of the decomposition of the high-boiling material

Product joining Michael is contained in the high boiling material, can be decomposed to a monomer containing (meth)acrylic acid as a main component. When in high-boiling material contains ester of (meth)acrylic acid, it can be hydrolyzed to (meth)acrylic acid and alcohol or can be extracted as features, in the form of ether, without decomposition, depending on the conditions.

The temperature of the decomposition reaction is brought to 110-250VaboutWith, preferably 120-230aboutC. figure 1 high-boiling material is heated in the heat exchanger for nagrywania temperature regulate. In another case than the case in which the heater is installed outside of the reactor decomposition And, as shown in figure 1, is suitable internal heater type steam coil installed in the reactor, decomposition, or a heater of the type of shirt that is installed around the reactor, decomposition, and may also be used in the heating device of any type.

Retention time for decomposition reaction varies depending on the presence or absence of a catalyst and the reaction temperature of decomposition. When the temperature of the decomposition reaction is low, this time is relatively long, such as 10-50 hours, and when the temperature of the decomposition reaction is high, it is 30 minutes to 10 hours. The pressure of the reaction may or conditions of reduced pressure, or atmospheric pressure.

The decomposition reaction can be carried out using only the high-boiling material as the object reaction. However, for the purpose of accelerating decomposition reactions, it can be carried out in the presence of an acid catalyst or in the presence of water. As a catalyst for the decomposition reaction mainly use acid or a Lewis acid, such as sulfuric acid, phosphoric acid, methanesulfonate acid, para-toluensulfonate acid or gloridomini. The catalyst and/or water can be pre-mixed with the high-boiling material, or may be supplied to the decomposition reactor And separately from the high-boiling material. When in high-boiling material contains a polymer, a polymerization inhibitor, a catalyst, etc., they usually remain and are concentrated in the residue of the decomposition without destruction.

The design of the reactor decomposition

The design of the reactor decomposition And may be of any design, such as design type of the column or the design type of tank. In the case of reactor type columns can be set as the contents of the dish or filling (Packed) materials that are commonly used in the distillation column, whereby it may be held not only the reaction of the decomposition, but can also be carried out the distillation operation that is preferred. As the filling material can be used such filling material, as, for example, a SULZER PACKING, made SULZER BROTHERS LTD., SUMITOMO SULZER PACKING or MELLAPACK manufactured SUMITOMO HEAVY INDUSTRIES, LTD., GEMPAK, made GLITSCH, MONTZ PACK, made MONTZ, GOODROLL PACKING, manufactured TOKYO TOKUSHU KANAAMI K.K., HONEYCOMB PACKING, made NGK INSULATORS, LTD. or IMPULSE PACKING, made NAGAOKA INTERNATIONAL CORPORATION.

As unusual filler can be, for example, mentioned ITALOX SADDLE, manufactured NORTON, TELLERETTE, made Nittetu Chemical Engineering Ltd., PALL RING, manufactured by BASF, CASCADE MINI-RING, made MASS TRANSFER or FLEXIRING manufactured JGC CORPORATION. Can be used any of such fillers or can be used several of them in combination.

The plates can be, for example, nozzle plates, perforated plates, bubble plates, sverhprochny plates or maximum flow plates having a drain pipe, or double plates or plates of the drive type and type toroids do not have drain pipes. These plates or filling (Packed) materials may be used in combination or such content may not be present in the reactor decay.

In this invention the fluid flow in the peripheral direction (spiral flow) is the current that is generated by force, and this can be done by applying high-boiling material or fluid returned from the sediment (nedogona) (liquid sludge)from the tangential direction of the reactor. When the inlet opening of the feed from the tangential direction is absent, the spiral is formed during mixing blades provided in the reactor, both these methods can be used in combination.

In the case of type reactor tank with plumage is ishibaysky blades, can be used sparging, if required. Mixing blades can be blades of any type until they are able to generate the peripheral current. Specifically, there may be mentioned anchor blades (at least one stage)multistage impeller blades, multi-angled blade blade, grating blade, MAXLEND-blades (trade name, manufactured SUMITOMO HEAVY INDUSTRIES, LTD.), FULLZONE VANES (trade name, manufactured SHINKO PANTEC CO., LTD.), etc. and can be used at least one type in at least one stage. FULLZONE blade are such that the radial flow-type blades attached in two steps in the direction of the rotation axis so that the blades are adjacent in the direction of the axis of rotation toward the direction of the axis of rotation so that their phases are offset from each other by no more than 90aboutand the lower part of one of the blades of the upper-stage neighboring in the direction of the axis of rotation is located below the highest part of the blade the lower level (see JP-A-7-33804). Especially preferred as the stirring blades are anchor blade, grating blade or blades FULLZONE.

As for the bubble plates (hereinafter called dampers, mounted together with mixing blades, in this breath is reenie there are no restrictions against them. Can be used with any type or bubble plates can not be installed. Specifically, there may be mentioned, for example, the type of rod, the type of record, type of comb and can be installed in at least one type and at least one connection. Especially preferred is the establishment of a single type of rod or one type of dish.

Unloading the remainder of the reactor decomposition

The rest of the expansion can be unloaded from the reactor decomposition in an appropriate way. Unloading position the bottom of the decomposition reactor can be anywhere, as long as it is part of the lower end of the column. It is preferably within 1/2 of the diameter of the column from the bottom of this lower part of the reactor. If it is located above the end portion, the end portion will accumulate solid. This residue is stored, for example, in the tank and then recycle it for processing by incineration or in the process of obtaining. On the other hand, acrylic acid, methacrylic acid, alcohol, etc. as decomposition products product join Michael, or air will be continuously discharged from the upper part (top of the column) of the decomposition reactor. They are discharged into the treatment system or recycle in a suitable position in the production process.

Option b

This is Ariant was achieved based on the discovery of the fact, the reaction of the decomposition product of joining Michael (meth)acrylic acid can be carried out without clogging for a long time by means of a pulsed discharge, i.e. the periodic discharge of the liquid bottom instead of a continuous discharge from the lower part of the reactor. The reason can be effectively prevented clogging, has not been elucidated fully. However, on the basis of experimental evidence, the authors of the present invention believe that the clogging in the pipe at a constant current is to disrupt the flow of liquid through periodic currents and due to the infringing actions of such fluid flow occlusion may extremely effectively be suppressed, despite the fact that the fluid flow will be temporarily staying.

The terms "(meth)acrylic acid and (meth)acrylic ester, product of joining Michael" and "a method of obtaining a (meth)acrylic acid" shall have the same meaning as in option A.

Scheme of the production line using the reaction of thermal decomposition of high boiling material

6 is an example of a production line using the reaction of thermal decomposition of this invention, which is the same as in the case of option a, except that denotes a heat exchanger in which rewane, F denotes a control valve for periodic discharge, and 3 denotes the supply line to the heat exchanger for heating.

High-boiling material is supplied from the line 1 in the reactor And decay. The feed to the reactor And the decomposition can be carried out continuously or periodically (semi-continuous), but preferred is a continuous flow. Valuable substance and part of the materials comprising the high-boiling material, formed in the decomposition reactor, continuously discharged in a gaseous state from the line extraction 6 and will return to this production process as it is in a gaseous state, or by cooling in a liquid state. When the decomposition reactor And the reactor is of the type column, part of the cooled fluid may be returned in the form of liquid phlegmy in the upper part of the column for the decomposition reaction. The liquid in the lower part is diverted from line 2 and through the pump In and part of it is served in a heat exchanger to heat and returns to the reactor decomposition of A. the Remainder will be discharged from this system of lines 4 through valve D regulation periodic unloading as one of the advantages of the present invention. Reference numeral 5 denotes a pipeline transportation in the reservoir for storage.

The terms "reaction of decomposition of high boiling material and the design of the reactor R is slorenia" are the same as in the case of option.

Periodic unloading

In option b the most significant feature is that the rest of the expansion is periodically discharged from the decomposition reactor. This periodic unloading is performed by the valve D regulation periodic unloading. The time of a closed state of the valve D is usually equal to 5 seconds - 5 minutes, preferably 10 seconds to 2 minutes, and the open state of the valve D is usually equal to 2 seconds - 5 minutes, preferably 3 seconds to 2 minutes. The share of the open state of the valve regulation D (the percentage of time of the open state(open state+time closed state)is preferably in the range of 2-50%, more preferably 5-30%. If the closed state is shorter, and the open state is longer than the above range, the effect of suppressing the clogging may be insufficient due to the inertia of the flow of residue decomposition. If the closed state is prolonged, and the time of the open state is short, the clogging of the pipeline is likely to occur due to the influence of the static state of the liquid in the pipeline, which is undesirable. When continuous discharge (degree open state: 100%) plugging the line the gadfly will take place, as is also evident from the comparative example below.

On the other hand, acrylic acid, methacrylic acid, alcohol, etc. as decomposition products product join Michael, or air will be continuously discharged from the upper part (top of the column) of the decomposition reactor. They are discharged into the treatment system or recycle in a suitable position in the way of getting.

Option

In the variant with the use of trays for distillation columns disk and toroidal plates, whereby can be solved the problems of adhesion, deposition and accumulation of solids. Namely, circular and toroidal plates are such that the disk plates and toroidal plates alternating manner are mounted with a suitable interval, and as shown in Fig.7 and 8, this design is very simple and the hole is extremely large, therefore can be solved the problems of adhesion, deposition and accumulation of solids.

Thus, using a distillation column with plates of the type disks and toroids, decomposition by-product and the extraction of valuable substances in obtaining (meth)acrylic acid can be carried out continuously. Plate type disks and toroids have a design that is chrisv the tea simple. Thus, in comparison with distillation column using conventional plates or conventional material-filler, there is an advantage in that the production cost of this distillation columns and expenses for design, such as the costs of making plates, can be very low.

Now will be described in detail practical variant of the method of decomposition by-product formed during retrieval (meth)acrylic acid in accordance with option C. First with reference to Fig.7 and 8 will be described the design of distillation columns with plates of the type disks and toroids, suitable for option C. Fig 7(a) is a schematic view in cross section showing the distillation column equipped with disks and toroids type of flat plates, and Fig.7(b) is an enlarged perspective view of main parts Fig.7(a). Next, Fig(a) is a schematic view in cross section showing the distillation column equipped with a disk and toroidal plates type of inclined plates, and Fig(b) is an enlarged perspective view of main parts Fig(a).

Plate type disks and toroids are such that the number plates in the form of discs and plates in the form of toroids alternating manner are suitable races what being between them in this distillation column, and in the distillation column 31 figure 7 in this column are interleaved image plates in the form of discs 32A and plates in the form of toroids 32V type of flat plates, while in the distillation column 3 Fig there are alternate ways of plates in the form of discs 34A and plates in the form of toroids 34B type of inclined plates. In distillation columns 31 and 33 in figures 7 and 8 has inlet openings for the liquid, and V and 33B are inlets for steam. Next, S and 33C are outlets for steam and 31D and 33D are outlet openings for the liquid bottom. 35 on Fig a distribution device (dispersing device).

The distance between the plates in the form of discs 32A and 34A and between the plates in the form of toroids 32V and 34B (L 7 and 8) is preferably at least 250 mm to suppress entrainment of liquid. If this distance L is excessively large, the height of the distillation column must be increased and, therefore, it is preferably a maximum of 500 mm

The shape of the top view of the plate in the form of a disc 32A or 34A is preferably an exact circle and its center is preferably located in the center of the distillation column. Similarly, the shape of the top view of the plate in the shape of a toroid 32V or 34B is preferably exact ring around and on uina the periphery of the plates in the form of a toroid 32V or 34B is preferably in close contact with the inner wall of the distillation column 31 or 33.

The diameter of the plates in the form of a disc 32A or 33A (D17 and 8) and the diameter of the orifice plates in the form of a toroid 32V or 34B (D27 and 8) (hereinafter sometimes called the "inner diameter") is appropriately selected in the range 55-74% of the internal diameter of the distillation column 31 or 33. This size corresponds to the range 30-55%, represented by the ratio of the open area in the distillation column 31 or 33.

Avoid short path (short pipe) running down the flow of liquid in the distillation column 31 or 33, the diameter D1plates in the form of a disc 32A or 34A is preferably slightly larger than the inner diameter of D2plates in the form of a toroid 32V or 34B.

As for the form of plates, are preferred plates 32A and 32V type of flat plates, as shown in Fig.7. However, as shown in Fig, using plates 34A and 34B, are slightly tilted relative to the direction of fluid flow, it is possible to further reduce the accumulation of solids. The angle in this case has no special limitation, but it is usually set in the range of 5-45aboutWith to the horizontal direction.

A method of setting plates in the form of discs 32A and 34A and plates in the form of toroids 32V and 34B in the distillation column 31 or 33 may be any method. It can be, for example, methods for the om fixing them by means of holders, projecting from the walls of distillation columns, by way of sticking them to the walls of the distillation column or the manner in which the respective plates in the form of discs and plates in the form of toroids entirely fixed with a vertical holder and mounted in the distillation column in the form of integral construction.

The number of plates plates in the form of discs and plates in the form of toroids, which must be installed in the distillation column is not particularly limited, and it is chosen appropriately so that you can achieve the capacity of Department required for this particular method. If the number of plates is too low, the distilled amount of high-boiling component tends to be large, and the amount of recycled component will be increased and the manufacturing capacity of this reactor for the decomposition will be reduced, which is undesirable. On the other hand, if the number of plates is increased more than necessary, will not only increase construction costs, but will also decrease the concentration by distillation in the upper part of the polymerization inhibitor contained in the liquid source material, resulting, probably, is undesirable polymerization reaction of the distillate that is tender is undesirable. Thus, the number of plates in the form of discs and plates in the form of toroids, which should be installed, preferably chosen in the range of 5-20 plates (number plates one plate in the form of a disc or a plate in the shape of a toroid will be considered as a single plate).

(Meth)acrylic acid in the variant with is preferably (meth)acrylic acid obtained by catalytic oxidation reaction in the vapor phase propane, propylene, acrolein, isobutylene, tert-butyl alcohol or the like, and a gaseous product of the oxidation reaction is rapidly cooled and quenched with water. Then carry out the separation of the water and (meth)acrylic acid by the method of azeotropic distillation that uses azeotropic solvent or extraction method using a solvent. Further, low-boiling compounds such as acetic acid, separated and then separated heavy component, such as product join Michael to obtaining (meth)acrylic acid of high purity. In another case, water and acetic acid can be separated simultaneously with the use of azeotropic agent. The above product join Michael will be concentrated in the high boiling fraction and preferably this fraction, i.e. the liquid in the lower part of the fractionation column, mixed with by-product formed in the pick-ether (meth)acrylic acid, so process them all together.

Ester of (meth)acrylic acid in the example is not particularly limited and may be, for example, methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, n-hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-octyl(meth)acrylate, methoxyethyl(meth)acrylate, isononyl(meth)acrylate or Isodecyl(meth)acrylate.

Product joining Michael is a by-product formed during the reaction or at the stage of purification in the method of obtaining a (meth)acrylic acid and ester of (meth)acrylic acid, and it is a substance containing (meth)acrylic acid, acetic acid, alcohol, or water, is joined by Michael reaction in α-position or β-position of the compounds having the group of the (meth)acrylic acid present in this way obtain. A compound containing the group of (meth)acrylic acid present in this method of production, can be, for example, (meth)acrolein, (meth)acrylic acid, carboxylic acid having a (meth)acryloyloxy group, such as β-aryloxyphenoxy acid or β-methacryloxyethyl acid (hereinafter both are called in the General form of a dimer containing (meth)acrylic acid, added by Michael to such (meth)acrylic acid, trimer (meth)acrylic acid (hereinafter called the ' trimer), having a (meth)acrylic acid, added by Michael in such a dimer, or tetramer (meth)acrylic acid (hereinafter referred to as a tetramer), with (meth)acrylic acid, added by Michael in such a trimer, or a corresponding ester of (meth)acrylic acid with a carboxylic acid having a (meth)acryloyloxy group esterified with alcohol. Next, in a similar manner may also contain a compound containing (meth)acrylic acid, added by Michael (meth)acrolein. Specifically, the product of the joining Michael the present invention includes β-aryloxyphenoxy acid or β-methacryloxyethyl acid and ether or aldehyde compound (β-aryloxypropanolamine or β-methacryloxyethyl), β-aloxiprin acid or esters, β-oxopropionate acid or β-oxidizable acid, and their esters or aldehydes, and their dimers, trimers, tetramer etc. and they β-acroloxidae, β-acetoxysilane, β-alkoxysilane and β-hydroxycodone. Further, the present compound containing acetic acid, added by Michael (meth)acryloyloxy group, although it may be in very small quantities.

In the variant with as a method of producing ether (meth)acrylic acid is usually used method R. the action of alcohol with (meth)acrylic acid for the esterification or the method of producing acrylic ester of higher alcohol by reaction of the ester of acrylic acid lower alcohol, higher alcohol for the transesterification. Further, this method of obtaining can be either periodic system or a continuous system. As catalyst for the esterification or interesterification usually use an acid catalyst.

The method of producing ether (meth)acrylic acid preferably includes the step of the reaction and the purification stage for holding washing, extraction, evaporation, distillation or the like as a single operation for separation from the catalyst, concentration, purification, etc. of the crude ester of (meth)acrylic acid obtained at this stage of the reaction. The molar ratio of the source material (meth)acrylic acid or ester of (meth)acrylic acid to alcohol in the reaction may be appropriately selected depending on the type and amount of catalyst used for this reaction, the reaction system, the reaction conditions or the type of alcohol used as the starting material.

Product joining Michael in the main side formed by this reaction, will concentrate in the lower part of the distillation column (fractionation column for the separation of high-boiling fractions. Thus, in this invention the liquid the lower part of the object, which must be processed is subjected to thermal decomposition, together with by-product with n is adidasa stage of obtaining (meth)acrylic acid, and received valuable component will be extracted for the reaction to ether with (meth)acrylic acid or the cleanup phase.

In this case, the distillation column separating the high-boiling fraction may vary depending on the type of the resulting ester of (meth)acrylic acid or method used, but usually it is a column separation (meth)acrylic acid and high-boiling fractions or column for separation of the ether with (meth)acrylic acid and high-boiling fractions or column for separation of (meth)acrylic acid, alcohol, and ether (meth)acrylic acid and high-boiling fractions. This invention can be applied to all of them.

In a liquid the bottom of the column separating the high-boiling fraction is concentrated above product join Michael, but, in addition, significant quantities of (meth)acrylic acid and/or ester (meth)acrylic acid and, in addition, contains the high-boiling components such as a polymerization inhibitor used in this way, the oligomer or polymer formed in this way, the high-boiling impurities in the source material or their reaction products. Further, in some cases, may contain the catalyst used for the stage of the esterification or interesterification.

As mentioned above, the product connection on Micah is Liu, side formed during the stage of obtaining a (meth)acrylic acid, is usually concentrated in the lower part of the distillation column (fractionation column for the separation of the product of (meth)acrylic acid from the heavy fraction. In this liquid the lower part also contains a significant amount of (meth)acrylic acid and, in addition, also contains a polymerization inhibitor used in this way, the oligomer formed in this way, or the high-boiling components.

In the variant with as a reactive distillation system, which simultaneously carry out the reaction of the decomposition product join Michael and the distillation and extraction of valuable substances that can be used with any system, such as a continuous system, the periodic system, paliperidonesee system or a system with periodic unloading, but preferred is a continuous system. Further, the type of reactor may be any selected from a reactor type full mixing with peremeshivajutsa tank reactor, reactor circulation type tank reactor full mixing or simple hollow reactor without limitation to any particular type.

As a catalyst can be used a known catalyst which is a Lewis acid or Lewis base but can be used for simple thermal decomposition without the use of catalyst. As conditions for the decomposition reaction temperature is usually equal to 120-280°C, preferably 140-240°and the retention time of the fluid based on the fluid discharge is 0.5-50 hours, preferably 1-20 hours. As for pressure reaction conditions are chosen so that most of the (meth)acrylic acid ester (meth)acrylic acid, alcohol, etc. that need to be extracted, distilled at the reaction temperature.

In the variant with a distillation column equipped with a plate-type disks and toroids shown in Fig.7 and 8, is installed in the reactor for reactive distillation. This part of the distillation column may be a column directly connected to the reactor, or independent column system which is connected to the steam system piping from the reactor and piping system for the supply of liquid from the distillation column, and hence this system is not particularly limited. Further, the heating system for reactive distillation is not particularly limited and may be a system of coil type reactor type internal mnogotranshevogo heat exchanger, system type outer jacket or system type of the external heat exchanger.

When the reactive distillation is carried out in a continuous system, the original mater what al can be fed to the part of the distillation column or in a part of the reactor at the bottom, but it is preferable to supply it part of the distillation column.

Further, in this invention a by-product formed during retrieval (meth)acrylic acid-containing product join Michael and by-product formed during retrieval ether (meth)acrylic acid, may be separately processed thermal decomposition or they can be mixed and processed thermal decomposition.

Option d

Option d is a variant of serving the oxygen or oxygen-containing gas directly into the distillate containing a decomposition product formed by the decomposition reaction of the above by-product, and option to suppress the polymerization of the easily curable compounds in the product decomposition of the effect of oxygen. As a result of numerous studies, it was found that polymerization lignopolimering compounds in the decomposition product can be sufficiently suppressed by adding an oxygen or oxygen-containing gas. This is attributed to the fact that the added oxygen will increase the vast polymerization of action inhibitor of polymerization, usually contained in the source material for the decomposition reaction.

In option d ester of (meth)acrylic acid is particularly not ogranichivaetsya, but there may be mentioned esters, similar to the one described in option C. Further, as product join Michael, may be mentioned the products similar to the one described in option C.

Feed liquid (hereinafter sometimes referred to as the high-boiling liquid), which must be submitted in the column of the decomposition reaction, also contains substances used or generated in the process of obtaining acrylic acid or esters of acrylic acid. Specifically, they are acrylic acid, esters of acrylic acid, maleic acid, esters of maleic acid, furfural, benzaldehyde, polymers, oligomers, alcohols, used as materials for producing esters, and the polymerization inhibitor (acrylate copper, dithiocarbamate copper connection (derived) phenol or a compound (derivative) fenotiazina etc).

The above dithiocarbamate copper may be the same as described in option A. Further, the above compound phenol may be the same as described in option A.

Depending on the specific method may contain substances other than the above.

(Meth)acrylic acid in option d is the same as described in option C. Next, a method of producing ether (meth)acrylic acid in option d includes, for example, the stage of interaction of alcohol with (meth)acrylic acid is for esterification using cation-exchange resin as a catalyst and purification step of carrying out the washing, extraction, evaporation, distillation or the like to separate the catalyst, concentration, purification, etc. of the crude solution of acrylic ester obtained by reaction stage. The molar ratio of the source material (meth)acrylic acid or ester of (meth)acrylic acid to alcohol on the reaction type and amount of catalyst used for this reaction, the reaction system, reaction conditions, etc. can be appropriately selected depending on the type of alcohol used as the starting material. Product joining Michael in the main side formed in the stage of the esterification reaction, will concentrate in the form of heavy fractions in the lower part of the reaction column to retrieve the variable component.

A by-product formed in obtaining acrylic acid by-product formed during retrieval of the acrylic ester can be subjected to decomposition together.

In option d for the reaction of the decomposition product of joining Michael can be used with any system, such as a continuous system, the periodic system, paliperidonesee system or a system with periodic unloading, but preferred is a continuous system. The type of reactor is also not particularly limited and may be use the van of any type such as the reactor type flow tubular reactor, flowing a thin-film reactor with the descent, peremeshivayte the reactor tank type tank complete mixing type reactor tank full mixing of the circulating type. To obtain the valuable components contained in the reaction product of decomposition, can be used a way to obtain them by evaporation or by distillation during the reaction or the method of obtaining them by evaporation or by distillation after the reaction of decomposition. However, to obtain a high output, it is preferable to the first reactive distillation.

In the case of reactive distillation pressure of the reaction depends mainly on following the reaction temperature and using such a pressure that a large part of valuable components, such as acrylic acid, acrylic ester, alcohol, etc. obtained in the decomposition reaction and contained in the original material for the decomposition reaction, will evaporate.

The catalyst may be selected from acids, Lewis bases Lewis, inorganic acid, such as sulfuric acid or phosphoric acid, and organic acids, such as methanesulfonate acid or para-toluensulfonate acid. In a column for the decomposition reaction can be served water, so according to the position can be carried out in the presence of high-boiling fraction and water.

The concentration of the acid catalyst is preferably 0.1 to 1.0 wt.%, particularly preferably 0.2 to 0.8 wt.% in the calculation of the loaded liquid.

The temperature of the decomposition reaction preferably equal to 110 -250aboutS, particularly preferably 120-230aboutC. the retention Time of the fluid based on the fluid discharge is preferably 0.5 to 50 hours. Further, when the temperature of the decomposition reaction is lower, the time is preferably 10-50 hours, and when the temperature of the decomposition reaction is higher, it is preferably 0.5 to 10 hours. Further, in the case where the decomposition reaction is carried out in a continuous reaction against the reaction time, the retention time of the fluid, calculated on paged fluid can be regarded as the reaction time. For example, in the case where the capacity of the liquid in the reactor is equal to 500 l, and the number of paged fluid is 100 l/h, the retention time is 5 hours.

For the distilling column decomposition reaction add oxygen or oxygen-containing gas (hereinafter sometimes referred to as "oxygen or the like") to prevent polymerization. As oxygen or the like can be used, for example, pure oxygen, a gas containing oxygen diluted with an inert gas, air or gas, the content is of ashy air, diluted with an inert gas. The inert gas may be, for example, nitrogen, carbon dioxide, argon or neon. Adding an inert gas is to prevent the formation of explosive gas. The inert gas preferably is present in 3,76-18,05 times the amount by volume relative to oxygen, and in the case of air, inert gas preferably is present in 0.3 to 3 times the amount by volume relative to the air. From a cost perspective, it is obvious that the air is cheaper than oxygen. Oxygen or the like is preferably added in a volume ratio of 0.0001 to 0.01, in particular in a volume ratio of 0.0005-0.005 factor, calculated as the ratio of oxygen to distilled gas.

Further, in this invention the addition of oxygen or the like in distilled gas columns for the decomposition reaction can be carried out in line after discharge from the column for decomposition reaction or oxygen or the like may be added in the upper part of the column for the decomposition reaction, which is mainly formed distilled gas.

11 is a diagram showing the process of the decomposition reaction. High-boiling liquid is fed to the column 41 of the decomposition reaction and thermally decompose. Here the column 41 of the decomposition reaction can be equipped with a mixer for mixing the liquid in the column. Next, column 41 of the decomposition reaction can be is provided with a jacket for heating the used water vapor or organic coolant as a heat source.

The liquid in the lower part of the column 41 decomposition reaction assign using a pump 42 and a portion of it using a recirculation line 43A is heated using a heat exchanger 43 for heating and recycle, and the rest is unloaded from the system.

The distillate formed by the decomposition reaction, is distilled from the top of column 41 of the decomposition reaction and, after the addition of oxygen or the like through the pipeline 44a of the upper part of the column is cooled and oiaut using a heat exchanger 44 and is introduced into the tank 5 to the cooled liquid. In the case of line phlegmy tank 45 for chilled liquid may be missing. Figure 11 gaseous component in the reservoir 45 for chilled divert fluid from the reservoir 45 to the cooled fluid to the heat exchanger 7 and is cooled, whereby a valuable substance will asiatica. Neskondensirovannyh gas fed to the apparatus for extracting a valuable substance or in a vacuum unit (not shown). The liquid in the tank 45 for chilled divert fluid through the pump 46 and part of it after adding the polymerization inhibitor recycle through the heat exchanger 44 in the reservoir 45 to the cooled liquid, and the rest of the output as a decomposition product. This product decomposition of return in the process of obtaining acrylic acid sludge is ester of acrylic acid, as was mentioned above.

The reactor 41 decomposition can be equipped with plates or filling (Packed) material, which is usually used in the distillation column. In this case it will work as a reactive distillation column for decomposition. As the filling material can be mentioned conventional filling material such as, for example, a SULZER PACKING, made SULZER BROTHERS LTD., SUMITOMO SULZER PACKING, manufactured SUMITOMO HEAVY INDUSTRIES, LTD., MELLAPACK, manufactured SUMITOMO HEAVY INDUSTRIES, LTD., GEMPAK, made GLITSCH, MONTZ PACK, made MONTZ, GOODROLL PACKING, manufactured TOKYO TOKUSHU KANAAMI K.K., HONEYCOMB PACKING, made NGK INSULATORS, LTD., or IMPULSE PACKING, made NAGAOKA INTERNATIONAL CORPORATION, or unusual filler, such as INTALOX SADDLE, made NORTON, TELLERETTE, made Nittetu Chemical Engineering Ltd., PALL RING, manufactured by BASF, CASCADE MINI-RING, made MASS TRANSFER, or FLEXIRING, made JGC CORPORATION. Can be used any of such fillers or can be used several of them in combination.

The plates can be, for example, nozzle plates, the plates in the form of perforated plates, bubble plates, sverhprochny plates, the maximum flow plates having a drain pipe, or double plates, etc. that do not have drain pipes. These plates or Packed materials can be used for the munali.

Further, such content may not be present in the column for the decomposition reaction. In this case, the distillation column or the like can be mounted as required in a particular case.

When the column 41 for decomposition reaction equipped with a mixing means mixing blades can be of any type, and, for example, they can be the anchor blades (at least one stage), multi-inclined impeller blades, as a special blades, MAXLEND-blades (bursting discs SUMITOMO HEAVY INDUSTRIES, LTD.) or FULLZONE-blades (bursting discs SHINKO PANTEC CO., LTD). Can be used several types in more than one level, i.e. in multi-stage designs. Especially preferred are the anchoring blades or grating lobes.

Bubble plates (valves)installed with mixing blades may be of any type. Specifically, they can be, for example, the type of rod, plate, type of comb and can be installed more than one type or more than one plate. However, bubble plates may be missing.

The fraction enriched (meth)acrylic acid ester, (meth)acrylic acid and alcohol, obtained by the decomposition reaction, remove completely for the stage of obtaining the acrylic ester. The place where re is to irculate extracted fraction, is not particularly limited. However, this fraction contains a small amount of light fraction and, therefore, it is preferable to carry out its recycling together in front of the stage of separation of the light fraction.

Option e

The invention of this option, e refers to the method of extraction of the acrylic acid. In particular, in the method which involves reacting acrylic acid, maleic acid, in particular containing acrylic acid gas obtained by the catalytic oxidation in the vapor phase propylene with a solvent for collecting the acrylic acid in the form containing the acrylic acid solution, the distillation of low-boiling component containing acrylic acid solution by azeotropic distillation or by straight distillation, then obtaining acrylic acid fractionation during thermal decomposition of the oligomer of acrylic acid contained in the residues (Neogene) the lower part of the distillation column, and removing acrylic acid and recycling it in the purification step, the invention of option e is the effective way removal of maleic acid as impurities from the liquid, which must be fed into the reactor for thermal decomposition, or from the distillate.

The invention of option e was made on the basis of detection by the authors of this izaberete the Oia following facts:

- Maleic acid is formed together with acrylic acid in the reactor for oxidation, is present in the form of dicarboxylic acids having two carbocycle group, in aqueous solution, but in the acrylic acid it can be in the form of maleic anhydride with one molecule of water, digidratirovannogo of its molecules. Maleic acid and maleic anhydride are in equilibrium in solution of acrylic acid, which must be submitted in an installation for extraction of the reaction of thermal decomposition of the oligomer acrylic acid, the concentration of water as a component with a low boiling point is low, therefore this equilibrium is displaced essentially in the direction of maleic anhydride.

- When adding water to the liquid portion of the maleic anhydride is converted to maleic acid in accordance with the quantity of water added.

- In the liquid (or gas) upper part of the column reactor thermal decomposition of water is present, formed by thermal decomposition of 3-hydroxypropionic acid, etc. and part of the maleic anhydride will interact with this water with the formation of maleic acid.

- For the reaction equilibrium takes time and balance will be accelerated by heating.

- The solubility of maleic acid in the acrylic acid t is aetsa low in comparison with maleic anhydride and probably, maleic acid shall be subjected to deposition.

The degree of precipitation depends on the concentration of maleic acid or water in the liquid and the temperature of operation and the deposition will be accelerated by adding a water-insoluble solvent.

- It is possible to facilitate the precipitation and separation of the decrease in solubility by conversion of maleic anhydride to maleic acid in the liquid, which must be fed into the reactor for thermal decomposition of acrylic acid, or in the liquid extracted from the reactor thermal decomposition.

Using this method, the circulation in the cleaning system of maleic acid involved in thermal decomposition and removal of the oligomer acrylic acid, formed at the stage of distillation and purification containing acrylic acid liquid, can be easily reduced by sedimentation and separation of solids from liquids using chemical equilibrium maleic acid and maleic anhydride, whereby it is possible to extract acrylic acid with no problem of clogging as a result of polymerization.

Now option e will be described in detail in relation to each of the objects Reactor thermal decomposition", "Getting solution of acrylic acid, Reaction of maleic acid", "Operation of sedimentation and sludge Separation".

The reactor thermal decomposition

The liquid in the lower part of the column for purification (product) acrylic acid or a liquid obtained by concentrating and heating the liquid bottom film evaporator or the like, is used as the liquid, which must be submitted, and thermal decomposition of the oligomer of acrylic acid is carried out in the temperature range 120-220°C. This stage of thermal decomposition and phase separation decomposed products can be carried out in the same equipment, such as reactive distillation column, or in individual equipments, such as the combination of the heating tank and the evaporator. For this reaction, thermal decomposition can be used catalyst. As the type of catalyst may be mentioned, for example, a compound having a secondary or tertiary amino group or a tertiary phosphine. However, the catalyst is not limited. Or the reaction of the decomposition can be carried out in the absence of any catalyst.

Obtaining a solution of acrylic acid

The liquid feed to the reactor thermal decomposition or liquid extracted from the reactor thermal decomposition (distillate)should be processed.

The concentration of maleic acid or maleic anhydride in sulecin the second liquid is in the range of 1.6-28 wt.%, preferably 2.5 to 25 wt.%. If the concentration of maleic acid is low, the precipitation tends to be difficult, and if this concentration is too high, increasing the loss of acrylic acid during the separation of precipitated maleic acid.

The water concentration is in molar ratio, shown as follows:

Water

------------------------- less than or equal to 1.0

maleic acid

+ maleic anhydride x 2.

Especially preferably, it is in the range [maleic anhydride] x 0.8 ≤ [water] ≤ [maleic acid] x 0.5 + [maleic anhydride]. If the water concentration is too high, the amount of precipitated maleic acid decreases and the time required for deposition, will be long.

The concentration of acrylic acid is equal to at least 70 wt.%. If it is below this, the nature of this liquid will be different and will be the case when the effect of the present invention may not be obtained.

The reaction of maleic acid

In the solution there are maleic acid and maleic anhydride. In comparison with maleic anhydride maleic acid has a low solubility in the acrylic acid. Thus, the greater the ratio of maleic acid/maleic anhydride in the solution, the more effective removal through which Sardinia.

To accelerate the formation of maleic acid by the interaction of maleic anhydride with water liquid temperature can be increased to 50-70°C. If the temperature rises above this range, the rate of formation of the oligomer acrylic acid will increase, whereby will decrease not only the efficiency of heating, decomposition and extraction of the oligomer, but also is likely to occur polymerization of acrylic acid, which is undesirable.

The reservoir for the reaction is not particularly limited. However, preferably it is equipped with a system for mixing mortar, such as mixing blades, or external circulation pump is used to prevent polymerization in the tank.

When the amount of maleic acid (without anhydride) in the solution exceeds 2 wt.%, the above operation may be omitted.

The operation of the deposition

Maleic acid is precipitated from the above solution. Used for such deposition vessel may be a vessel used for the above-described operations, or they may be separate tank. The time required for deposition is preferably in the range of 0.5-5 hours, along with the time of the above operation. If this time is too short, the effectiveness osuzhdeni which is usually weak. From the point of view of efficiency, the longer the required time, the better. However, the equipment required for this purpose must be large, which is uneconomical.

The temperature of this operation is in the range 20-70aboutWith, preferably 20-40°C. If the temperature of this operation is too low, the cooling load will increase, which is uneconomical. Further, the melting point of acrylic acid is 13°and may be freezing acrylic acid. The higher the temperature, the more is polymerized acrylic acid and the solubility of maleic acid will increase, which is undesirable.

Can be added to the solvent, capable of forming double layers of liquid water, through what can be an increased amount of deposition and the deposition rate of maleic acid. The solvent which can be used for this purpose may be, for example, aliphatic hydrocarbons such as hapten or octene, an aromatic hydrocarbon, such as toluene, xylene or ethyl benzene, ether, such as isopropylacetate, or a ketone such as methyl isobutyl ketone, but they are not alone. More preferred is a solvent of low polarity, such as aromatic or aliphatic hydrocarbons. The number is predpochtitel is but 0.5 to 4-fold volume relative to the volume of the solution extracted acrylic acid. If this number is too small, then usually do not get adequate actions in relation to the number of deposition. On the other hand, an excessive amount of added burdens this process in terms of size and efficiency of the installation, which is uneconomical. Exactly can be used azeotropic agent used for the dehydration stage distillation, and in this case, thermal load to remove the added solvent essentially will not grow.

Mixing can be done to prevent deposits on the wall of the reactor crystals deposited in the tank. In addition, the crystals having a uniform particle size, will be deposited by stirring, which facilitates subsequent phase separation.

The sludge separation

Department besieged maleic acid can be carried out in the vessel used for the deposition. However, it is convenient to carry out this division in relation to the liquid withdrawn from the tank for the deposition, so that the operation can continue.

As a means for removal of precipitated maleic acid are paged fluid may be useful, for example, the replaceable strainer. However, this tool is not limited to them and can be used the usual separator for separating firmly what about the substances and liquids. Can be used thickener (hub), reservoir sedimentation, cyclone separator, strainer, centrifugal separator (centrifuge) or the like Separated liquid can be removed through the opening. However, it can be dissolved in a small amount of warm water and can be disposed of as waste water. Depending on the installation of separated solid material can be continuously discharged. A solution of acrylic acid after removal of the precipitate contains water and an organic solvent added for the operation of the deposition, and, therefore, preferably is recycled to the stage of purification before column purification of acrylic acid.

In the above-described operation, the concentration of maleic acid in the extracted acrylic acid will be reduced to the level of 1.4 to 3 wt.%. The contents of this level will not be harmful influence on the purity of this product, even when recycling at the stage of cleaning.

Option f

The invention of option f is a way of establishing the level meter of the liquid used for this equipment to obtain lignopolimering connection. More specifically, it relates to a method of establishing part detection (detecting part) the high pressure side of the meter liquid level and refers to the method of installation and the measurer of the liquid level, whereby it became possible continuous operation of this equipment without clogging detection part of the meter liquid level.

Fig is a view showing the entire installation, in which the method of establishing meter liquid level variant of the invention f is applied to the column of the decomposition reaction (high boiling material) and to the reservoir of gas-cooled liquid upper part in obtaining acrylic acid, Fig is a partial enlarged view showing the gauge of level of a liquid, mounted on the column of the decomposition reaction (high boiling material) Fig and Fig is a partial enlarged view showing the gauge of level of a liquid, mounted on the tank of gas-cooled fluid top Fig.

First, with reference to Fig will be described in the General form of device for producing acrylic acid. 6A is a column decomposition reaction (high boiling material) and the supply line 61 is attached to the casing 6A of the decomposition reaction (high boiling material). 6V1is the pump lower part, and the intake side of the pump 6V1the lower part is connected to the line 62 of the discharge fluid of the lower part connected with the lower part of the column 6A decomposition reaction (high boiling material), and its output side connected to the line 64 unloading ostad the decomposition.

6C is a heat exchanger for heating, and the intake side of the heat exchanger for heating connected to the line 63 feed to a heat exchanger for heating, branches off from line 64 of the discharge of residue decomposition and its output side connected to the wall of the lower side of the column 6A decomposition reaction (high boiling material) by means of a pipeline.

6D is a heat exchanger for cooling the gas in the upper part of the column, and the inlet side of the heat exchanger 6D for gas cooling of the upper part of the column connected to the line 66 of gas extraction decomposition, attached to the upper part of the column 6A decomposition reaction (high boiling material), and its output side connected to the intake side of 6TH tank of gas-cooled fluid to the upper part of the column through a pipeline.

Further, the output side of 6TH tank of gas-cooled fluid to the upper part of the column connected to the line 68 discharging cooled gas liquid upper part of the column through line 65 to the discharge fluid of the lower part of the tank and the pump 6V2and gas-cooled liquid, the upper part of the column is transferred via the line 68 in the following setting.

Line 69 return chilled liquid, branches off from line 68 discharging cooled gas liquid upper part of the column attached to the inlet side of the heat is of obmennik 6D for gas cooling of the upper part of the column.

6F is a heat exchanger for cooling the gas exhaust through the vent and the intake side of the heat exchanger 6F to cool this off-gas is attached to the 6TH tank of gas-cooled fluid to the upper part of the column by means of the pipeline. The exhaust gas passing into the heat exchanger 6F for cooling the flue gas will be cooled and after extracting valuable substances contained in the gas to be in line 67 discharging the exhaust gas.

H1and H2are the gauges liquid level of the meter type differential pressure, and method of installation of such meters liquid level H1and H2is a very important characteristic of the present invention.

Namely, the high pressure side of the meter H1the liquid level of the meter type differential pressure connected to the line 62 discharging liquid bottom through line 11 detecting the high pressure side and low pressure side of the meter H1the liquid level of the meter type differential pressure attached to the wall of the bottom side of the column 6A decomposition reaction (high boiling material) through the line 12 to the detection of the low pressure.

The high pressure side of the meter H2the liquid level of the meter type differential pressure connected to the line 6 discharging liquid bottom through line 13 to the detection side high pressure, and the low-pressure side of the meter H2the liquid level of the meter type differential pressure attached to the bottom of the 6TH tank of gas-cooled fluid to the upper part of the column through line 14 detection of the low pressure.

Will now be explained in detail specific examples of the method of setting the above-described measuring liquid level type gauges, differential pressure H1and H2with reference to figures 13 and 14.

On Fig (1) and (2) 6A is the column of the decomposition reaction (high boiling material) and the liquid accumulated in the lower part of the column 6A decomposition reaction (high boiling material)is removed from the column through line 62 to the discharge of liquid the bottom of the column, consisting of a short pipe a discharging liquid bottom attached to the bottom of the column, and pipe 62b unloading of liquid the bottom of the column.

H1is a measure of the liquid level type of temperature measuring differential pressure and the high pressure side of the meter H1the liquid level of the meter type differential pressure attached either to a short pipeline a or pipe 62b, consisting of line 62 discharging liquid bottom through line 11 detection of the high-pressure side, consisting of a short pipe 11 is detecting the high pressure side and the pipeline 11b detect the high pressure side.

Angle attach α between line 11 detecting the high pressure side and a line 62 discharging liquid bottom equal 5-90°preferably 10-90°.

If this angle of connections is less than 5°, the accession is practically difficult to implement, and if this angle is joining more than 90°then the solid substance in the liquid will probably flow in line 11 of the detection of the high-pressure side, which is undesirable.

The ratio of the size of D2/D1is 1-20, preferably 1.3 to 10, where D1is the diameter of the pipe line detection of the high-pressure side, and D2is the diameter of the pipe line discharging liquid.

If the relation D2/D1less than 1, the solid substance in the liquid will probably flow in line 11 of the detection of the high-pressure side, which is undesirable, and if D2/D1exceeds 20, the detection of the liquid level, is likely to be difficult.

The low-pressure side of the meter H1the liquid level of the meter type differential pressure attached to the wall of the bottom side of the column 6A decomposition reaction (high boiling material) through line 12 to the detection of the low pressure, consisting of a pipe 12b detection of the low pressure and short the th pipeline 12A detection of the low pressure.

Fig (1) is an example in which the line 11 of detecting the high pressure side connected to the vertical portion of the line 62 of the discharge fluid of the lower part, whereas Fig (2) is an example in which the line 11 of detecting the high pressure side is attached to the horizontal part of the line 62 discharging liquid bottom.

On Fig (1) and (2) 6E is a tank of gas-cooled fluid to the upper part of the column, and the liquid accumulated in the 6TH tank of gas-cooled fluid to the upper part of the column is drained from the tank through line 65 to the discharge fluid of the lower part of the tank, consisting of a short pipe 65A unloading of liquid the bottom of the tank, attached to the bottom of the tank, and pipe 65b unloading of liquid the bottom of the tank.

H2is a measure of the liquid level type of temperature measuring differential pressure and the high pressure side of the meter H2the liquid level of the meter type differential pressure attached either to a short pipe 65A or pipe 65b, a line 65 to the discharge fluid of the lower part of the tank through line 13 to the detection of the high-pressure side, consisting of a short pipe 13A detection of the high-pressure side and pipeline 13b detection side height is anyone pressure.

Further, the low-pressure side of the meter H2the liquid level of the meter type differential pressure attached to the underside of the tank E gas-cooled fluid to the upper part of the column through line 14 detection of the low pressure, consisting of a pipe 14b detection of the low pressure and short pipe 14a detection of the low pressure.

Angle attach α between line 13 detection of the high-pressure side and a line 65 to the discharge fluid of the lower part of the tank and the size of D2/D1where D1is the diameter of the pipe line 13 detection of the high-pressure side, and D2is the diameter of the pipe line 65 of the discharge fluid of the lower part of the tank, are acceptable if they meet the relation between the center line 11 of the detection of the high-pressure side and the line 62 of the discharge fluid, as described in detail with reference to the above example Fig.

Here Fig (1) is an example in which the detection line 13 the high pressure side connected to the vertical portion of the line 65 of the discharge fluid of the lower part of the tank, and Fig (2) is an example in which the detection line 13 the high pressure side is attached to the horizontal part of the line 65 of the discharge fluid of the lower cha the tee tank.

The above line of discharge of the liquid attached to the place where fluid accumulates containing lignopolimering connection, such as a distillation column, the reservoir phlegmy for distillation columns, column decomposition reaction, film evaporator, tank cooled gas liquid upper part of the column, vertical storage tanks, horizontal storage tank or cistern, and line detection the high pressure side of the meter liquid level attached to this place in such a way that can be measured liquid level.

Further, the level meter fluid used in this invention may be, for example, by measuring the liquid level of the meter type differential pressure gauge liquid level type glass measuring instrument or type tubular measuring device direct observation or level indicator pressure type.

Preferably, if the inlet gas and/or liquid is connected to the line detection of the high-pressure side and/or line detection of the low pressure side of such meter liquid level.

When through some operational change of a solid substance in the liquid flowing in this line detection, it is possible if try uploading this solids by gas and/or liquid. Such a gas or a liquid can be fed continuously or periodic mode.

The gas used for this purpose is preferably nitrogen, carbon dioxide or the like, and as a liquid it is preferable to use the same fluid that flows in the line of discharge of the liquid, such as acrylic acid or acrylic ester.

Further, preferably, the part is heated or heated to prevent deposition of solids in the liquid line detection of the high-pressure side and/or line detection of the low pressure gauge liquid level.

The measurement is easily curable compounds using the method of establishing the level meter fluid of the present invention is effective in obtaining (meth)acrylic acid or ester of (meth)acrylic acid.

Further, as the fluid measured by the meter liquid level, is especially effective liquid containing at least one type selected from a dimer of acrylic acid, esters β-(meth)aryloxypropanolamine acid, esters β-alkoxyamino acid, β-oxopropanoic acid and esters β-oxopropanoic acid formed as by-products during retrieval (meth)acrylic acid or its esters.

POR WHAT MEASURES

Now the invention will be described in more detail with reference to examples and comparative examples, but the invention is not limited to these examples. Here is the analysis of the composition of the high boiling material in accordance with a conventional method using a gas chromatograph equipped with a flame ionization detector (FID).

EXAMPLE A1

The reaction of the decomposition of the high-boiling material was performed using the setup shown in figure 1. As decomposition reactor, used reactor type columns, made of Hastelloy C and having an outer diameter of 600 mm and a length of 1800 mm as a starting material of the high-boiling material having the following composition was continuously applied from line 1 with a speed of 580 kg/hour.

The composition of the high boiling material (source material)
The butyl acrylate:22 wt.%
Butylβ-butoxypropan:67 wt.%
Butylacrylamide:4 wt.%
Butylβ-oxopropionate:2 wt.%
Hydroquinone:3 wt.%
Methoxinine:2 wt.%

Further, as a catalyst for the decomposition reaction was filed Mas.%-aqueous solution of sulfuric acid at the rate of 58 kg/h (10 wt.% regarding fed liquid source material) and the decomposition reaction was carried out at the pressure of the reaction of 100 kPa at the decomposition temperature of 190° With over a retention time of 1 hour.

From line 6 in the upper part of the valuable substance, consisting mainly of acrylic acid and butanol were removed at a speed of 438 kg/h, while the remainder of the reaction having the following composition was discharged from the system through line 4 at 200 kg/hour.

The composition of the remainder of the reaction
The butyl acrylate:of 11.0 wt.%
Butylβ-butoxypropan:68.5 wt.%
Butylacrylamide:2.0 wt.%
Butylβ-oxopropionate:0.3 wt.%
Hydroquinone:to 8.7 wt.%
Methoxinine:5.8 wt.%
Butanol:to 0.8 wt.%
Sulfuric acid:2.9 wt.%

From line 2 of the reactor And the liquid bottom were taken at a speed of 35350 kg/h and from line 5 (see figure 4), installed in the tangential direction relative to reactor A, 350 kg/h of liquid, the lower part was returned to the reactor through valve speed control current (not shown in figure 1)that is installed on the line 5. The remainder 34800 kg/hour returned into the reactor And through the heat exchanger for heating and the return line 3-2 for heating. In this mo is UNT formed spiral flow in the lower part of the reactor And the liquid, return from line 5. Further, a pipe for line 3 was 4V, and a pipe for line 5 was 1 (1,5) Century

After continuous operation for 6 months, the operation was stopped and examined the internal space of the column of the decomposition reaction. Did not observe accumulation in the lower part of the column of the decomposition reaction. In addition, during this operation no clogging in the transport pipeline for the remainder of the reaction.

COMPARATIVE EXAMPLE A1

The operation was performed using the same setup (figure 1), as in example A1, except that the accession line 5 to reactor decomposition reaction has set in towards the centre of the column, i.e. not in the tangential direction. After working for 2 months in the pump suddenly occurred cavitation. This column decomposition reaction was terminated and the internal space of the column were examined, resulting in the observed accumulation of solids in the lower part of the column of the decomposition reaction. The condition of the solids accumulated in the bottom of the column of the decomposition reaction, shown in figure 5.

EXAMPLE A2

Using the same setup (figure 1), as in example A1, the high-boiling material having the following composition was continuously applied from line 1 with a speed of 580 kg/hour.

The composition of the high boiling material (source material)
Acrylic acid:of 45.3 wt.%
Maleic acid:10.0 wt.%
The dimer of acrylic acid

(aryloxyphenoxy acid):
42,4 wt.%
Hydroquinone:1.3 wt.%
Phenothiazines:1.0 wt.%

The decomposition reaction was carried out at the pressure of the reaction 72 kPa at the decomposition temperature of 190°during the retention time of 1 hour. From line 6 in the upper part of the valuable substance, consisting mainly of acrylic acid, extracted with a speed of 449 kg/h, while the remainder of the reaction having the following composition was taken from the system through line 4 with a speed of 131 kg/hour.

The composition of the remainder of the reaction
Acrylic acid:8.0 wt.%
Maleic acid:of 14.0 wt.%
The dimer of acrylic acid

(aryloxyphenoxy acid):
67,2 wt.%
Hydroxyine:5.8 wt.%
Phenothiazines:4.4 wt.%
The oligomer and polymer:0.6%

The liquid bottom Castellani decomposition reaction were taken from the tip 3/4B (line 2), set in the lowest position of the lower part, and filed in the Century pump Via a pump In it was taken from the line 4 at a speed of 131 kg/h, while in line 3 it was served at a speed 32000 kg/h liquid return to the column of the decomposition reaction through the heat exchanger for heating with the use of tubing having a diameter 4V.

On the other hand, the liquid in the lower part of the column of the decomposition reaction was applied in the form of liquid returning through the pump from the line 5 with the formation of currents in the peripheral direction in the column of the decomposition reaction. The diameter of the pipe line 5 was 1 and 1/2 (1,5), and the flow rate was 400 kg/h and such regulation was performed using a valve controlling the speed of current (not shown in Fig.), installed in the line 5.

After continuous operation for 6 months, the operation was stopped and examined the internal space of the column of the decomposition reaction. Did not observe accumulation in the lower part of the column of the decomposition reaction. In addition, during this operation no clogging in the transport pipeline for the remainder of the reaction.

COMPARATIVE EXAMPLE A2

The work was performed using the same setup as in example A2, except that the accession line 5 to reactor decomposition reaction has set in is upravlenii center of the column, and not in the tangential direction.

After working for 70 days in the pump suddenly occurred cavitation. This column decomposition reaction was terminated and the internal space of the column were examined, resulting in the observed accumulation of solids in the lower part of the column of the decomposition reaction. The condition of the solids accumulated in the bottom of the column of the decomposition reaction, shown in figure 5.

EXAMPLE A3

The reaction of the decomposition of the same high-boiling material as in example A2 was performed using a column of the decomposition reaction (without septum), shown in figure 3, with anchor blades as stirring blades. This column decomposition reaction has a shirt and has a diameter of 600 mm and a height of 1000 mm, the diameter of the anchor blade was 540 mm Work was carried out under the same operating conditions as in example A2, bringing the rotational speed of anchor blades up to 20 rpm six months Later, this work was stopped and the interior space of the column were examined, resulting in the observed accumulation of solids in the column. In addition, observed a blockage in the discharge line installed in the lowest part of the bottom of the column, during the same period.

EXAMPLE b1

The reaction of the decomposition vysokoyebased the material was performed using a setup shown in Fig.6. As decomposition reactor, used reactor type columns, made of Hastelloy C and having an outer diameter of 600 mm and a length of 1800 mm as a starting material of the high-boiling material having the following composition was continuously applied from line 1 with a speed of 580 kg/hour.

The composition of the high boiling material (source material)
The butyl acrylate:22 wt.%
Butylβ-butoxypropan:69 wt.%
Butylacrylamide:4 wt.%
Butylβ-oxopropionate:2 wt.%
Hydroquinone:2 wt.%
Methoxinine:1 wt.%

Further, as a catalyst for the decomposition reaction was applied to 1 wt.%-aqueous solution of sulfuric acid at the rate of 58 kg/h (10 wt.% regarding fed liquid source material) and the decomposition reaction was carried out at the pressure of the reaction of 100 kPa at the decomposition temperature of 190°during the retention time of 1 hour.

From the top of column a valuable substance, consisting mainly of acrylic acid and butanol were removed at a speed of 449,5 kg/h and on the other hand, from the bottom of the column, has periodically removed if the residue of the reaction of the following composition at a speed of 188,5 kg/hour. That is, the valve D regulation periodic discharge, shown in Fig.6, worked for a time closed 75 seconds and time of the open state of 5 seconds (the ratio of the open state: 6,3%).

Paged fluid directed into the storage tank for the remainder of the reaction, installed at a distance of 800 m, with the use of tubing having a diameter of 3/4 In (inner diameter: 22.2 mm). Continuous operation was carried out for 3 months, but did not observe any blockage in the transport pipeline for the remainder of the reaction. The results are shown in table 1.

The composition of the remainder of the reaction
The butyl acrylate:to 11.7 wt.%
Butylβ-butoxypropan:72,7 wt.%
Butylacrylamide:2.1 wt.%
Butylβ-hydroxypropionate:0.4 wt.%
Hydroquinone:6.2 wt.%
Methoxinine:3.1 wt.%
Butanol:to 0.8 wt.%
Sulfuric acid:3.1 wt.%

In addition, the degree of decomposition of the corresponding components in the high-boiling material were as follows:

Butylβ-butoxypropan:about 67 wt.%
Butylacrylamide:about 83 wt.%
Butylβ-hydroxypropionate:about 74 wt.%

Here for each component in the high-boiling material was determined by the degree of decomposition of [1-(discharged quantity of the decomposition reactor)/(submitted number in the decomposition reactor)] x 100 (%).

EXAMPLES b2 - b4

Residual liquid reaction obtained using the same setup and operation as in example b1 was sent to the storage tank for the remainder of the reaction in the same manner as in example b1, except that the periodic time of discharge (the ratio of the open state) has changed relative to this condition, as shown in table 1. If any condition is not observed clogging in the transport pipeline in the continuous operation for 3 months. In addition, the intensity of decomposition of high boiling material was essentially the same as in example b1, in respect of each component. These results are shown in table 1.

COMPARATIVE EXAMPLE b1

Residual liquid reaction obtained using the same setup and operation as in example b1 was sent continuously to the storage tank for the remainder of the reaction t is Kim the same way as in example b1. Around the fifth day after the beginning of the work observed a gradual decrease in the transported quantity of residual water of reaction. Conducted mechanical shaking of the pipeline from the outside, whereby clogging partially and temporarily eliminated, but full recovery of the transported quantity was impossible. After that, the number of discharge continuously decreased and, accordingly, the retention time in the reactor decay gradually increased. As a result, the condition of the fluid in the remainder of the reaction became very viscous and on the 25th day of the decomposition reactor had to be terminated. In addition, the degree of decomposition of the high-boiling material during stationary operation before stop was essentially the same as in example b1, in respect of each component. These results are shown in table 1.

EXAMPLES b5 to b8

Using the same setup as in example b1, the decomposition reaction is carried out by applying a high boiling point material having the following composition as the source material at a speed of 580 kg/hour.

The composition of the high boiling material (source material)
Acrylic acid:to 46.0 wt.%
Malinova the acid: 10.0 wt.%
The dimer of acrylic acid

(aryloxyphenoxy acid):
42,4 wt.%
Hydroquinone:0.9 wt.%
Phenothiazines:0.7 wt.%

The reaction conditions of decomposition were pressure reaction 72 kPa, decomposition temperature 190aboutC and a retention time of 1 hour and no filing of a catalyst.

From the top of column a valuable substance, consisting mainly of acrylic acid and butanol were removed at a speed of 449,5 kg/h, while from the bottom of the column was periodically extracted residue of the reaction of the following composition at a speed of 130,5 kg/hour. That is, the time of a closed state and the open state of the valve D regulation periodic discharge, shown in Fig.6, has established, as shown in table 2, and perform this operation.

Paged fluid directed into the storage tank for the remainder of the reaction, installed at a distance of 800 m, with the use of tubing having a diameter of 3/4B (inner diameter: 22.2 mm). Continuous operation was carried out for 3 months, but did not observe any blockage in the transport pipeline for the remainder of the reaction. In addition, the degree of decomposition of the dimer of acrylic acid was approximately 72%. These results are shown in table 2.

The composition of the remainder of the reaction
Acrylic acid:to 9.0 wt.%
Maleic acid:of 14.0 wt.%
The dimer of acrylic acid

(aryloxyphenoxy acid):
for 69.5 wt.%
Hydroquinone:4.0 wt.%
Phenothiazines:3.1 wt.%
The oligomer and polymer:0.4 wt.%

COMPARATIVE EXAMPLE b2

Residual liquid reaction obtained using the same setup and operation, as in examples b5 to b8, was sent continuously to the storage tank for the remainder of the reaction in the same manner as in example b5-b8. Around the fifth day after the beginning of the work observed a gradual decrease in transported to the storage tank for the amount of residual liquid reactions. Conducted mechanical shaking of the pipeline from the outside, whereby clogging partially and temporarily eliminated, but full recovery of the transported quantity was impossible. After that, the number of discharge continuously decreased and, accordingly, the retention time in the reactor decay gradually increased. As a result, the condition of the fluid in the remainder of the reaction became very viscous and on the 18th day of work reacto the and decomposition had to be terminated. These results are shown in table 2.

Table 1
ExamplesComparative example
b1b2b3b4b1
The control valve periodic unloadingThe open state (s)531020Continuously open
Time closed state (s)75601201800
The ratio of the open state6,34,87,710100
State of the transport pipeline in relation to the residual liquid reactionThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThe transported quantity is gradually decreased and on the 25th

the day of the decomposition reactor was

to be stopped
Table 2
ExamplesComparative example
b5b6B7b8b2
The control valve periodic unloadingThe open state (s)531020Continuously open
Time closed state (s)6040901200
The ratio of the open state7,771014,3100
State of the transport pipeline in relation to the residual liquid reactionThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThere is no clogging in the tech. 3 monthsThe transported quantity is gradually decreased and on the 18th

the day of the decomposition reactor was

to be stopped

EXAMPLE C1

The decomposition reaction was carried out in accordance with this invention using as the starting material liquid of the lower part of the column separating the high-boiling fraction in the method of producing methyl acrylate, and the source material had the following SOS is AB:

The composition of the liquid bottom
Acrylic acid:20 wt.%
β-oxopropionate acid:1 wt.%
Methyl-β-hydroxypropionate:8 wt.%
β-aryloxyphenoxy acid:8 wt.%
Methyl-β-acrilchimproject:7 wt.%
β-methoxypropionate acid:41 wt.%
Methyl-β-methoxypropionate:12 wt.%
Other high-boiling components, etc.:3 wt.%

As the reactor part in the lower part of the column of the decomposition reaction used a mix tank, made of Hastelloy C having an inner diameter of 1000 mm and height 2000 mm, and the coolant was applied to the outer jacket to control the temperature at 200°and the pressure of the reaction was maintained at 130 kPa. Next, at the top of this stir tank reactor was connected distillation column having an inner diameter of 400 mm and a height of 4000 mm, and, in addition, a capacitor, whereby the decomposition reaction was performed using reactive distillation.

Internal about what transto this distillation column, shown in Fig.7, the plate 2A in the form of disks with diameter D1280 mm, in five steps with a distance of 600 mm from the top to the bottom, and between them were installed plate 2B in the form of toroids with a hole having an inner diameter of D2260 mm, in four stages with the same distance.

The feeding position of the liquid source material is positioned above the disk, the upper stage and the aforementioned liquid bottom was applied at 150 kg/hour. The retention time of the fluid controlled by the liquid level in the reactor decay and adjust so that the retention time on the basis of paged fluid was equal to 10 hours. The reactor was continued for 1 month at a temperature decomposition reaction 200°C, resulting in the observed increase of the pressure drop and could work in stable conditions.

After this operation of the reactor internal space of the distillation column were subjected to visual inspection, which did not observe the accumulation of solids. The number of discharge residue decomposition during this period averaged 76 kg/h and the composition was analyzed by gas chromatography to obtain the following results:

The composition of the balance
Water:0.2 wt.%
Methanol:0.2 wt.%
MMA:0.3 wt.%
Acrylic acid:39 wt.%
β-oxopropionate acid:0.3 wt.%
Methyl-β-hydroxypropionate:7 wt.%
β-aryloxyphenoxy acid:4 wt.%
Methyl-β-acrilchimproject:4 wt.%
β-methoxypropionate acid:31 wt.%
Methyl-β-methoxypropionate:8 wt.%
Other high-boiling components, etc.:6 wt.%

COMPARATIVE EXAMPLE C1

The decomposition reaction was performed using the same setup, same source material and the same reaction conditions as in example C1, except that as part of the distillation columns used distillation column equipped with a 2000 mm spiral (coil) as supplementary material, instead of the plates in the form of disks and toroids. No clear differences in comparison with example C1 in relation paged quantity or composition of the residue, but during this period, the difference is Alenia between the upper and lower part of the distillation column was gradually increased and after 1 month observed an increase in differential pressure of 2.6 kPa. Next, after 1 month the reactor was stopped and the Packed material was taken out and examined visually, as a result it was found that accumulated a significant amount of solids.

As can be seen from the results of the above examples and comparative examples, using the method of the present invention can be continuous operation under stable conditions without disruption, for example, due to clogging or increasing pressure drop and to prevent the deposition or accumulation of solids.

EXAMPLE d1

The reaction of the decomposition of the high-boiling liquid was performed using the setup shown figure 11. The decomposition reactor has a diameter column of 1000 mm and the length of the column 2800 mm and made of Hastelloy C. the high-boiling liquid had the following composition: 22% of butyl acrylate, 67 wt.% butylβ-butoxypropyl, 4 wt.% butylenediamine, 2 wt.% butylβ-hydroxypropionate, 3 wt.% hydroquinone and 2 wt.% methoxyimino and this liquid was applied at a speed of 580 kg/hour.

As a catalyst for the decomposition of a 1 wt.% an aqueous solution of sulfuric acid was applied in a mass ratio of 10% with respect to the supplied liquid and the decomposition reaction was carried out at the pressure of the reaction of 100 kPa at a temperature of decomposition 190aboutWith over retention time hour whereby the decomposed gas containing the 45.8 wt.% of butyl acrylate, 23 wt.% acrylic acid, 16 wt.% butanol, to 11.9 wt.% water, 2.9 wt.% butylβ-butoxypropan, of 0.003 wt.% hydroquinone, 0.007 wt.% methoxyimino and 0.39 wt.% other components were obtained from the upper part of the column of the decomposition reaction at a speed of 437,9 kg/hour. To the heat exchanger for cooling the gas decomposition liquid obtained by cooling the gas decomposition, returned with a speed of 800 kg/hour.

As oxygen or the like filed the air at a speed of 3 Nm3/hour and nitrogen as inert dilution gas at a rate of 3 Nm3per hour in the pipeline 44a of the upper part of the column, as shown in figure 11.

After continuous operation for 3 months operation of the reactor was stopped and examined the internal space of the column of the decomposition reaction. Not watched polymer in the inner space of the column decomposition reaction or the heat exchanger for cooling the gas in the upper part of the column.

COMPARATIVE EXAMPLE d1

The work was performed using the same setup as in example d1, except that the oxygen or the like, the air at a speed of 6 Nm3/hour and nitrogen as the dilution inert gas at a speed of 6 Nm3per hour fed into the recirculation line 43A before the heat exchanger 43 for heating, i.e., not the pipeline 44a of the upper part of the column.

After continuous operation for 3 months, the reactor was stopped and examined the internal space of the column of the decomposition reaction. Watched the polymer in the inner space of the column of the decomposition reaction. The polymer was not observed in the heat exchanger 44 for cooling the gas in the upper part of the column.

COMPARATIVE EXAMPLE d2

The reactor was performed in the same manner as in comparative example d1, except that the air was applied at a rate of 3 Nm3/hour and nitrogen as inert dilution gas was served with a speed of 3 Nm3/hour.

After continuous operation for 3 months, the reactor was stopped and examined the internal space of the column of the decomposition reaction. Watched the polymer in the inner space of the column of the decomposition reaction, but his number was approximately 1/3 of this amount in the comparative example d1. In addition, the polymer was also observed in the heat exchanger for cooling the gas in the upper part of the column.

EXAMPLE d2

Decomposition of high boiling liquid was performed using the same setup as in example d1. High-boiling liquid had the following composition: 5.3 wt.% of acrylic acid, 10 wt.% maleic acid, 42,4 wt.% dimer of acrylic acid (aryloxypropanolamine acid), 1.3 wt.% hydroquinone and 1 wt.% fenati is Zina and this liquid was applied with a speed of 580 kg/hour.

The decomposition reaction was carried out at the pressure of the reaction 72 kPa at the decomposition temperature of 190°during the retention time of 1 hour, whereby was obtained a gas decomposition containing an 85.1 wt.% acrylic acid, to 8.7 wt.% maleic acid, 2.1 wt.% dimer of acrylic acid (aryloxypropanolamine acid), 0.03 wt.% hydroquinone and 4,07 wt.% other components of the upper part of the column of the decomposition reaction at a speed of 449,5 kg/hour. In the heat exchanger for cooling the gas decomposition liquid obtained by cooling the gas decomposition, returned with a speed of 500 kg/hour.

As oxygen or the like filed the air at a speed of 2 Nm3per hour in the pipeline 44a of the upper part of the column, as shown in figure 11.

After continuous operation for 3 months operation of the reactor was stopped and examined the internal space of the column of the decomposition reaction. Not watched polymer in the inner space of the column decomposition reaction or the heat exchanger for cooling the gas in the upper part of the column.

COMPARATIVE EXAMPLE d3

The reactor was performed using the same setup as in example d1, except that as oxygen or the like, the air was applied at a rate of 3 Nm3/h in-line recirculation 3A.

After continuous use for 3 months operation of the reactor OST alibali and examined the internal space of the column of the decomposition reaction. Watched the polymer in the inner space of the column of the decomposition reaction. In addition, the polymer was also observed in the heat exchanger for cooling the gas in the upper part of the column.

EXAMPLE E1

The liquid extracted from the reactor thermal decomposition
Acrylic acid:88 wt.%
The dimer of acrylic acid:1.1 wt.%
The trimer of acrylic acid:100 wt. mind
Maleic acid:1.5 wt.%
Maleic anhydride:5.7 wt.%

Water:

Water

------------------------------(molar ratio)=0,34

maleic acid +

maleic anhydride x 2

Operation

20 ml of the liquid of the above composition was placed in a test tube with a stopper and subjected to horizontal shaking in an oil bath at 70°C for 2 hours with an amplitude of 3 cm at a cycle of 1 sec. Then added toluene in the amount of two volumes volume ratio and the mixture was left to stand at 35°C for 1 hour, after which the precipitated solid substance was separated. The separation of the solids was carried out at room temperature using vacuum filtration using a filter paper with a hole the parties 1 μ . Separated solid substance contained mixed crystals 96% maleic acid and maleic anhydride and acrylic acid and very small amounts of impurities, impregnated in them. The concentration of maleic acid with maleic anhydride after removal of the solids was 2.6 wt.%, as it was calculated through the elimination of added toluene.

EXAMPLE E2

The separation of the solid matter carried out under the same conditions as in example E1, except that did not add toluene. The concentration of maleic acid with maleic anhydride after removal of the solids was 3.2 wt.%.

EXAMPLE E3

The operation was conducted under the same conditions as in example E1, the addition of 0.08 wt.% water when heated at 70aboutC. the Amount of water at this time was:

Water

------------------------------(molar ratio)=0,38

maleic acid +

maleic anhydride x 2

The concentration of maleic acid with maleic anhydride after removal of the solids was 2.4 wt.%.

COMPARATIVE EXAMPLE E1

The operation was conducted under the same conditions as in example E2, except that I added 3 wt.% water during heating at 70aboutC. the Amount of water at this time was:

Water

-------------------------------(molar ratio)=1,63

maleic anhydride x 2

Not observed deposition of solids and the concentration of maleic acid with maleic anhydride was unchanged 7.2 wt.%.

EXAMPLE f1

The reaction of the decomposition of the high-boiling liquid was performed using the setup shown in Fig and 13.

High-boiling liquid had the following composition: 22% of butyl acrylate, 67 wt.% butylβ-butoxypropyl, 4 wt.% butylenediamine, 2 wt.% butylβ-hydroxypropionate, 3 wt.% hydroquinone and 2 wt.% methoxyimino and this liquid was applied with a speed of 580 kg/hour.

As a catalyst for the decomposition of a 1 wt.%-aqueous solution of sulfuric acid was applied in a mass ratio of 10% with respect to the supplied liquid and the decomposition reaction was carried out at the pressure of the reaction of 100 kPa at a temperature of decomposition 190aboutWith over a retention time of 1 hour, whereby the residue of the reaction, containing an 11.7 wt.% of butyl acrylate, 68.5 wt.% butylβ-butoxypropyl, 2 wt.% butylenediamine, 0.3 wt.% butylβ-hydroxypropionate, to 8.7 wt.% hydroquinone, 5.8 wt.% methoxyimino, 0.8 wt.% butanol and 2.9 wt.% sulfuric acid was given with the speed 200,1 kg/hour and unloaded from the bottom.

The liquid in the lower part of the column of the decomposition reaction were unloaded from the line 62 to the discharge fluid of the lower part that is attached in the lower position the Institute this bottom. Measuring liquid level H1in the lower part was measuring the liquid level of the meter type differential pressure and was installed as shown in Fig (1). Angle attach α between line 11 detection of the high-pressure side and the line of discharge of the liquid bottom was installed as an angle of 45°.

After continuous operation for 6 months operation of the reactor was stopped and examined the short pipe 11a of the detection of the high-pressure side and the pipeline 11b of the detection part of high-pressure lines 11 detecting the high pressure side of the meter H1liquid level. As a result of this survey were not observed deposits in any of them.

COMPARATIVE EXAMPLE f1

The work was carried out under the same conditions as in example f1, except that the line 11 of detecting the high pressure side of the meter H1the liquid level of the meter type differential pressure H1connected horizontally with the wall of the lower side of the column decomposition reaction of 6A. After working for 2 months in the pump lower part of In1suddenly there was cavitation. Work columns 6A decomposition reaction was immediately stopped and the interior space was examined, whereby it was found that the liquid was not present is in the lower part of the column 6A of the decomposition reaction and the reading on the meter H 1the liquid level was erroneous.

Short pipe 11a of the detection of the high-pressure side and the pipeline 11b of the detection part of high-pressure lines 11 detecting the high pressure side of the meter H1the liquid level was examined, whereby it was found that the short pipe 11a and the pipeline 11b were corked.

COMPARATIVE EXAMPLE f2

The work was carried out under the same conditions as in example f1, except that the line 11 of detecting the high pressure side of the meter H1the liquid level of the meter type differential pressure H1attach angle attach α 45° to the wall of the lower side of the column 6A decomposition reaction.

After working for 3 months in the pump lower part of In1suddenly there was cavitation. Work columns 6A decomposition reaction was immediately stopped and examined the interior space. In the result, it was found that the liquid was not present in the lower part of the column And decomposition reactions, and the reading on the meter H1the liquid level was erroneous.

Short pipe 11a of the detection of the high-pressure side and the pipeline 11b of the detection part of high-pressure lines 11 detecting the high pressure side of the meter H1level the fluid examined, whereby it was found that the short pipe 11a and the pipeline 11b were corked.

EXAMPLE f3

The operation of evaporation, satisfying the following conditions, was performed using a film evaporator.

As the composition of the starting material (crude acrylic monomer) mixture of 66.6 wt.% acrylic acid, 8.0 wt.% maleic acid, to 25.0 wt.% the oligomer of acrylic acid, 0.5 wt.% hydroquinone and 0.5 wt.% fenotiazina, was applied at 85°at the rate of 3000 kg/hour.

This operation was carried out at the pressure of the upper part of column 9 kPa and at a pressure lower part 10 kPa at a temperature of the upper part of the column 95°and the temperature of the lower portion 98°whereby from the top of this column were unloaded 53% of the added amount and got acrylic acid with a purity of at least 88 wt.%.

From the bottom of the unloaded mixture containing 41,1 wt.% acrylic acid, 10.9 wt.% maleic acid, 46,16 wt.% the oligomer acrylic acid, of 0.92 wt.% hydroquinone and 0.92 wt.% fenotiazina.

The liquid in the lower part of the thin film evaporator was unloaded using the line of discharge of liquid the bottom, attached to the lowest position of the lower part. Measuring the liquid level in the lower part was measuring the liquid level of the meter type differential pressure was set the priority, as shown in Fig (1). Angle attach α between line 11 detection of the high-pressure side and the line of discharge of the liquid bottom was installed as an angle of 45°.

After continuous operation for 6 months, the operation was stopped and a short pipe 11a of the detection of the high-pressure side and the pipeline 11b of the detection part of high-pressure lines 11 detection meter liquid level was examined. In the result it was found that none of them were fat.

COMPARATIVE EXAMPLE f3

The operation of the evaporation was conducted under the same conditions as the conditions in example 2, except that the line 11 of detecting the high pressure side of the gauge of level of a liquid of the type of meter pressure drop was attached to the wall of the lower side film evaporator.

After working for 1 month in the pump lower part suddenly occurred cavitation. The film evaporator is stopped and examined the interior space. It was found that the liquid film evaporator was not present and the reading on the meter liquid level was erroneous.

Short pipe 11a of the detection of the high-pressure side and the pipeline 11b of the detection part of high-pressure lines 11 of the detection side of the high pressure level meter fluid examined, whereby it was found that the short pipe 11a and the pipeline 11b were corked.

INDUSTRIAL APPLICABILITY

A. According to this invention in the process of extracting valuable substances by heating and decomposition of high boiling material containing the product of the joining Michael (meth)acrylic acid, the residue of the decomposition reaction can be transported without clogging of the reactor decay in the storage tank, whereby it will be possible continuous operation for a long time.

b. Further, according to the method of decomposition by-product formed during retrieval (meth)acrylic acid of the present invention, during the extraction of valuable substances, such as (meth)acrylic acid, ester of (meth)acrylic acid and alcohol, by thermal decomposition using a reactive distillation system a by-product formed during retrieval (meth)acrylic acid and/or by-product formed during retrieval ether (meth)acrylic acid, it becomes possible to perform continuous operation in stable conditions, prevention of adhesion, deposition or accumulation of solids and maintaining the speed of the extraction of this valuable substance at a high level without any such PR is the issue, as a blockage (occlusion) or an increase in differential pressure distillation column as a result of violations of state contact gas-liquid. In addition, in this invention can be used distillation column, having a very simple design, resulting in the advantage that the cost of this design will be very low in comparison with other distillation columns using a plate or Packed material.

C. Further, according to this invention can be processed on the decomposition product of joining Michael formed by side on the stage of obtaining a (meth)acrylic acid and/or ester (meth)acrylic acid, stabilized conditions whereby (meth)acrylic acid, ester of (meth)acrylic acid and alcohol etc. can be extracted at high speed retrieve.

d. Further, according to this invention contains the acrylic acid gas obtained by the catalytic oxidation of propane or propylene lead in the interaction with the solvent for collecting the acrylic acid in the form containing acrylic acid solution obtained containing acrylic acid solution is distilled for purification of acrylic acid, whereas the oligomer of acrylic acid from the liquid, the lower part containing the oligomer acrylic acid, obtained from the olony cleaning, thermally decompose and can be extracted acrylic acid with a low content of maleic acid.

E. Further, if the apparatus for receiving lignopolimering connections use a method of establishing measuring liquid level, it is possible to prevent the flow of solids present in the liquid lignopolimering connection, in-line detection of the high-pressure side of the meter liquid level. Thus, this part of the detection probe liquid level will not cause the measured fluid, resulting in possible accurate measurement continuous level meter liquid, whereby the plant can operate for an extended period of time.

1. A method of obtaining a (meth)acrylic acid by catalytic oxidation of propane, propylene or isobutylene in the vapor phase with the separation of the final product and education as a by-product of high-boiling mixture directed to decomposition, characterized in that the high-boiling mixture, which contains the product of the joining Michael, containing water, alcohol or (meth)acrylic acid attached to (meth)acryloyloxy the group that is decomposed in the reactor thermal decomposition with simultaneous distillation of decomposition products in the distillation columns is e, from which is taken in the form of distillate (meth)acrylic acid, and the liquid stream containing the resulting residue decomposition, forcibly attach the peripheral direction before its discharge from the reactor.

2. The method according to claim 1, characterized in that the fluid flow in the peripheral direction give agitating blades mounted in the reactor decay.

3. The method according to claim 1, characterized in that the fluid flow in the peripheral direction give the liquid supplied from the outside of the reactor decay.

4. The method according to claim 3, characterized in that the liquid supplied from the outside of the reactor decay, is a high-boiling material, supplied as source material, or return fluid stream of liquid discharged from the decomposition reactor.

5. The method according to any one of claims 1 to 4, characterized in that the fluid flow is periodically discharged from the decomposition reactor.

6. The method according to any one of claims 1 to 4, characterized in that during the extraction of valuable substances by carrying out distillation and thermal decomposition of high-boiling mixture, the distillation is carried out with the use of a distillation column, which is provided inside the plates of the type disks and toroids.

7. The method according to any one of claims 1 to 4, characterized in that the distillate from the reactor decay add content is the overall oxygen gas.

8. The method according to any one of claims 1 to 4, characterized in that the liquid to be added to the reactor thermal decomposition, or from the liquid extracted from the reactor thermal decomposition, precipitated and separated maleic acid contained in the specified fluid.

9. The method according to any one of claims 1 to 4, characterized in that the reactor thermal decomposition of the installed meter liquid level and line detection the high pressure side of the meter liquid level is connected to the discharge line of the liquid reactor decay.

10. A method of obtaining a (meth)acrylic acid by catalytic oxidation of propane, propylene or isobutylene in the vapor phase and, if necessary, the stage of esterification to obtain the ester of (meth)acrylic acid interaction with alcohol, with formation of high-boiling by-products subjected to thermal decomposition and distillation, characterized in that at a time when high-boiling mixture (hereinafter referred to as the high-boiling material)containing the product of the joining Michael decomposed in the reactor, decomposition for extraction of (meth)acrylic acids, liquid balance reactions discharged through forced make the fluid flow in the peripheral direction of this liquid residue the reaction in the reactor decay.

11. The method according to claim 10, Otley is audica fact, this fluid flow in the peripheral direction of give due to the stirring blades installed in the reactor decay.

12. The method according to claim 10 or 11, characterized in that these mixing blades are anchor blade, multi-blade blades, multi-inclined impeller blades or grating lobes.

13. The method according to claim 10 or 11, characterized in that the design of the stirring blades is such that on rotation of the rod, installed vertically in the Central part of the reactor, radial flow-type blades attached in two or more steps in the direction of the axis of rotation, so that the blades are adjacent in the direction of the axis of rotation toward the direction of the axis of rotation so that their phases are shifted relative to each other by not more than 90°and the lower part of one of the blades of the upper-stage neighboring in the direction of the axis of rotation is located below the highest part of the blades of the lower level.

14. The method according to claim 10, characterized in that the fluid flow in the peripheral direction give the liquid supplied from the outside of the reactor decay.

15. The method according to claim 10 or 14, characterized in that the liquid supplied from the outside of the reactor decay, is a high-boiling material, served as the source material, or return fluid liquid residue of the reaction, discharged from the decomposition reactor.

16. A method of obtaining a (meth)acrylic acid, which is a way of obtaining acrylic acid, methacrylic acid or ester of (meth)acrylic acid by the reaction involving the catalytic oxidation in the vapor phase propylene, propane or isobutylene, and then, if necessary, the reaction involving the stage of esterification, characterized in that at a time when high-boiling mixture (hereinafter referred to as the high-boiling material)containing the product of the joining Michael decomposed in the reactor, decomposition for extraction of (meth)acrylic acid, a liquid residue of the reaction periodically discharged from the decomposition reactor.

17. The method according to item 16, characterized in that the stop time of the discharge is 5 C - 5 min and unloading time is 2 - 5 minutes

18. The method according to item 16 or 17, characterized in that the liquid high-boiling material is continuously fed into the reactor decay and (meth)acrylic acid is continuously discharged from the vapor phase.

19. The method of decomposition by-product formed in obtaining (meth)acrylic acid by oxidation of propylene or isobutylene, or upon receipt of ether (meth)acrylic acid by the interaction of the acid with the alcohol, by introducing side cont the KTA in the reactor thermal decomposition, equipped with a distillation column, while carrying out the decomposition and distillation to recover valuable product, characterized in that, as specified distillation columns use the distillation column, which is provided inside the plates of the type disks and toroids.

20. The method according to claim 19, characterized in that the by-product formed during retrieval (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining (meth)acrylic acid as a by-product formed during retrieval ether (meth)acrylic acid is a liquid, the lower part of the fractionation column for separating the high-boiling fraction at the stage of purification of the ester of (meth)acrylic acid.

21. The method according to claim 19 or 20, characterized in that the by-product formed during retrieval (meth)acrylic acid, and/or by-product formed during retrieval ether (meth)acrylic acid, contains the product of the joining Michael, containing water, alcohol or (meth)acrylic acid attached to (meth)acryloyloxy group.

22. The method according to claim 19 or 20, characterized in that the reaction temperature of thermal decomposition is equal 120-280°and the response time of thermal decomposition is 0.5-50 hours

23. The method of decomposition by-product formed Ave is obtaining (meth)acrylic acid by oxidation of propylene or isobutylene, or upon receipt of ether (meth)acrylic acid interaction with alcohol, in the decomposition reactor with distillation of the product of decomposition, characterized in that the distillate from the reactor decay add oxygen or oxygen-containing gas.

24. The method according to item 23, wherein the by-product formed during retrieval (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining (meth)acrylic acid as a by-product formed during retrieval ether (meth)acrylic acid is a liquid, the lower part of the fractionation column the final stage of obtaining ether (meth)acrylic acid or precipitation columns separating (meth)acrylic acid.

25. The method according to item 23 or 24, characterized in that it is subject to decomposition by-product contains a product join Michael.

26. The method according to item 23 or 24, characterized in that the gas containing oxygen is air or oxygen diluted with an inert gas.

27. The method according to any one of claims 1, 10, 16, 19 or 23, characterized in that the gas containing oxygen is added to the discharge line for distillate from the reactor decomposition or in the upper part of the reactor decay.

28. The method of obtaining acrylic acid by catalytic oxidation of propane or propylene by contacting the gaseous products of reaction with the solvent for the extraction of acrylic acid in the form of the of astora, contains acrylic acid and subsequent purification of the acid by distillation of the solution, characterized in that the residues obtained from the lower part of the fractionation column to acrylic acid, or a liquid obtained by heating and kontsentrirovaniem such residues, served in the reactor thermal decomposition for the decomposition of the oligomer of acrylic acid in the liquid and the obtained acrylic acid is extracted at the stage of purification in which the fluid to be fed into the reactor thermal decomposition, or from the liquid extracted from the reactor for thermal decomposition, precipitated and separated maleic acid contained in the liquid.

29. The method according to p, characterized in that the composition of the liquid to be fed into the reactor thermal decomposition, or liquid extracted from the reactor thermal decomposition, regulate the obtaining of a solution containing at least 70 wt.% acrylic acid, 1,6-28 wt.% maleic acid and/or maleic anhydride and water, with a molar ratio

and maleic acid precipitated at 20-70°in the range of 0.5-5 h followed by filtration and separation.

30. The method according to p or 29, characterized in that during the operation of the Department of maleic acid type aliphatic or aromatic Ugledar the d in 1/2-to 4-fold volume per volume of solution extracted acrylic acid.

31. The method according to item 30, wherein the added hydrocarbon solvent is used for collection containing acrylic acid gas, or azeotropic agent used for dehydration distillation purification of acrylic acid.

32. Device for producing (meth)acrylic acid by extraction of high-boiling by-products formed during the oxidation of propylene, comprising a reactor thermal decomposition and distillation column, the level meters and the line of discharge of the liquid containing an easily curable compounds, characterized in that place, where fluid accumulates, a measuring liquid level, recording the differential pressure and line detection the high pressure side of the meter liquid level is connected with a discharge line for the collected liquid.

33. Installation p, characterized in that the angle of attach α between line detection of the high-pressure side and the line of discharge of the liquid is 5-90°.

34. Installation p, characterized in that the ratio of the size of D2/D1is 1-20, where D1is the diameter of the pipe line detection of the high-pressure side, a D2is the diameter of the pipe line discharging liquid.

35. Installation p, otlichayas the same time, what line of discharge of the liquid attached to the distillation column, the reservoir return phlegmy distillation column, the column for the decomposition reaction, film evaporator, reservoir fluid from condensed gas to the upper part of the column, vertical storage tanks, horizontal storage tank or cistern.

36. Installation according to any one of p-35, characterized in that the line detection of the high-pressure side and/or line detection of the low pressure level meter fluid is heated or warmed up.

37. Installation p or 35, characterized in that the line detection of the high-pressure side and/or line detection of the low pressure level meter fluid connected to the inlet opening for a gas and/or liquid.

38. Installation p or 35, characterized in that easily curable compound is a (meth)acrylic acid or its ester and the liquid being measured by the level meter fluid comprises at least one compound selected from a dimer of acrylic acid, esters β-(meth)aryloxypropanolamine acid, esters β-alkoxyamino acid, β-oxopropanoic acid and esters β-oxopropanoic acid formed as by-products when obtaining (meth)acrylic acid is or its ester.

Priority items:

16.05.2002 according to claims 1-4, 10-15, 16-18;

04.12.2001 on pp.5-9, 32-38;

25.12.2001 on p-22;

05.12.2001 on PP-27;

18.12.2001 on PP-31.



 

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