Method of producing (met) acrylic acid and complex (met) acrylic esters

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid and complex (met)acrylic esters, involving the following stages: (A) reacting propane, propylene or isobutylene and/or (met)acrolein with molecular oxygen or with a gas, containing molecular oxygen through gas-phase catalytic oxidation, obtaining crude (met)acrylic acid; (B) purification of the obtained crude (met)acrylic acid, obtaining a (met)acrylic acid product; and (C) reacting raw (met)acrylic acid with alcohol, obtaining complex (met)acrylic esters, in the event that the installation used in any of the stages (B) and (C), taking place concurrently, stops. The obtained excess crude (met)acrylic acid is temporarily stored in a tank. After restoring operation of the stopped installation, the crude (met)acrylic acid, stored in the tank, is fed into the installation, used in stage (B), and/or into the installation used in stage (C). (Met)acrylic acid output of the installation used in stage (A) should be less than total consumption of (met)acrylic acid by installations used in stages (B) and (C).

EFFECT: the method allows for processing (met)acrylic acid, temporarily stored in a tank, when stage (B) or (C) stops, without considerable change in workload in stage (A).

2 ex

 

The technical field to which the invention relates.

The present invention relates to a method for producing (meth)acrylic acid and complex (meth)acrylic esters, and more particularly to a method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters, including the stage of (A) obtaining a crude (meth)acrylic acid; (B) purifying the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and (C) interaction of the crude (meth)acrylic acid with an alcohol, to obtain the complex (meth)acrylic esters in which, when set, used at any stage (B) and (C)carried out in parallel to each other, stops, get the excess crude (meth)acrylic acid from step (A) is temporarily stored in the tank, and when stopped the install again begins to work, the crude (meth)acrylic acid, stored in the tank, can be handled without any change in workload setup used in stage (A).

The level of technology

A common method of obtaining a (meth)acrylic acid includes a step (A) interaction of propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular oxygen, using the method of gas-phase catalytic oxidation, adding a reactive gas containing the produced (meth)acrylic KIS the GTC, in water, to obtain its aqueous solution, and then removing components with low boiling points, such as water and acetic acid from aqueous solution, to obtain the crude (meth)acrylic acid; and a phase (B) purification of the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid. In addition, (meth)acrylic acid obtained above, enter into interaction with alcohol at the stage (C) to obtain the complex (meth)acrylic esters.

Typically, the crude (meth)acrylic acid obtained in the above stage (A)is quite suitable for use as the source (meth)acrylic acid to obtain compound (meth)acrylic esters. For this reason, the manner in which the portion of the crude (meth)acrylic acid obtained in stage (A), is fed to stage (B) to obtain from it the product of (meth)acrylic acid, while the remainder of the crude (meth)acrylic acid is fed to the step (C) to obtain from it a complex (meth)acrylic esters is preferable to ensure a good efficiency of production of the relevant products, as well as on the basis of economic considerations, such as low cost of installation.

As described above, when the crude (meth)acrylic acid obtained in the installation used in stage (A), the settlement of which shall serve installation used in stages (B) and (C)carried out in parallel to each other, when any of the facilities used in stages (B) and (C)stops because of her refusal, the crude (meth)acrylic acid, which must be submitted stopped the installation, temporarily stored in the tank, thereby making possible the continuous operation of the other stages.

As a conventional method, implemented by consumption of crude (meth)acrylic acid, stored in the tank, is known such a method in which the crude (meth)acrylic acid is fed from the unit used in stage (A), in the setup used in stages (B) and (C), is reduced by lowering the workload of the installation used in stage (A), and crude (meth)acrylic acid, stored in the tank, enters the setup used in stages (B) and (C), the amount corresponding to the decrease in the number of crude (meth)acrylic acid is fed from the unit used in stage (A), thereby controlling the amount of crude (meth)acrylic acid, stored in the tank. This is because the performance of the setup used in stage (A), is usually calculated in such a way as to be identical to or slightly greater than the overall performance of the plants used in stages (B) and (C), taking into account the future increase in the number of proizvodimyh products. More specifically, since the amount of crude (meth)acrylic acid obtained in stage (A)is identical to or greater than the number of crude (meth)acrylic acid is used in stages (B) and (C), is usually necessary to reduce the working load of the installation used in stage (A), to handle the excess crude (meth)acrylic acid, stored in the tank.

However, if the working load setup used in stage (A), is changed, for example, if you change the working load distillation column used in stages (A) to remove components with low boiling points, (meth)acrylic acid has a tendency to polymerization in the distillation column, which leads to problems such as clogging, due to the resulting polymers. In particular, in the case where an aqueous solution of acrylic acid is distilled in the column for azeotropic distillation in the presence of an azeotropic solvent, there is a tendency to a negative impact on the process of distillation as the operating load of the column.

As the method for stable operation of distillation columns for a long period of time, preventing the occurrence of clogging due to polymerization in it, even if the working load of distillation columns is changed, know the ten this way, where the performance decreases when the produced amount of (meth)acrylic acid is reduced by α% in comparison with the value under normal operating conditions, the flowing amount of fluid/gas in the distillation column is reduced in a controlled manner to (100-α/2)% or more compared with the number occurring during normal conditions (for example, published patent application of Japan No. 2003-183219). However, in the above method, since the workload is also changed, the manifestation of the disadvantages associated with changes in workload, is inevitable.

Accordingly to the present time, there is a need to provide a method capable of processing the crude (meth)acrylic acid, temporarily stored in the tank, when stage (B) or (C) stops, without any significant changes in workload stage (A).

The problem that should be solved by the inventions

The present invention is intended to solve the above conventional problems. The aim of the present invention is to provide a method of producing (meth)acrylic acid and complex (meth)acrylic esters, which includes stages:

(A) interaction of propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular Ki is oxygen, using the method of catalytic gas-phase oxidation, to obtain the crude (meth)acrylic acid;

(B) purification of the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and

(C) communicating the crude (meth)acrylic acid with an alcohol, to obtain the complex (meth)acrylic esters

in which, when the installation is used at any stage (B) and (C)carried out in parallel to each other, stops, received excess crude (meth)acrylic acid is temporarily stored in the tank, and when a job is suspended installation is resumed, the crude (meth)acrylic acid, stored in the tank, can be processed without any changes workload setup used in stage (A).

Means for solving the problem

As a result of the earlier studies of the authors of the present invention to solve the above problems found that if the capacity of the plant that is used in stage (A), is calculated so that it was lower than the total consumption of plants used in stages (B) and (C), the crude (meth)acrylic acid, stored in the tank, can accordingly be processed in the units used in stages (B) and (C), without any significant changes in workload setup used to study the (A).

The present invention is based on the above data. For this purpose, in one aspect the present invention provides a method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters, which includes stages:

(A) interaction of propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular oxygen, using a gas-phase method for the catalytic oxidation, to obtain the crude (meth)acrylic acid;

(B) purification of the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and

(C) communicating the crude (meth)acrylic acid with alcohol to obtain a complex (meth)acrylic esters

and if you stop the installation used at any stage (B) and (C)carried out in parallel to each other, the resulting excess crude (meth)acrylic acid is temporarily stored in the tank, and after the resumption of the suspended installation crude (meth)acrylic acid, stored in the tank, enters the setup used in stage (B), and/or installation used at the stage (C), where the performance of the setup used in stage (A), is calculated so that it was lower than the total consumption of installations used on a hundred is the second (B) and (C).

Action inventions

In the method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters in accordance with the present invention, which includes the stages of (A) obtaining a crude (meth)acrylic acid; (B) purifying the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and (C) communicating the crude (meth)acrylic acid with an alcohol, to obtain the complex (meth)acrylic esters

in which, when the installation is used at any stage (B) and (C)carried out in parallel to each other, stops, received excess crude (meth)acrylic acid is temporarily stored in the tank, and

crude (meth)acrylic acid, stored in the tank, can be processed without any changes in workload in the installation used in stage (A), when resuming stopped the installation.

The preferred embodiment for carrying out the invention

The present invention is described in detail below. A method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters in accordance with the present invention includes a stage (A) interaction of propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular oxygen, using the method of catalytic gas-phase is R, obtaining a crude (meth)acrylic acid; (B) purifying the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and (C) communicating the crude (meth)acrylic acid with an alcohol, to obtain the complex (meth)acrylic esters. Stage (B) and (C) provide for the after stages (A) and are parallel to each other. Part of the crude (meth)acrylic acid obtained in stage (A), arrives at the above stage (B) to obtain from it the product of (meth)acrylic acid, while the remaining crude (meth)acrylic acid is fed to the step (C) to obtain from it a complex (meth)acrylic esters.

In the production method of the present invention, when an installation used at any stage (B) and (C), stops, you must temporarily save the raw (meth)acrylic acid, which must be entered in the stopped the installation in the tank. The tank is connected with the associated facilities used in stages (A), (B) and (C)through pipelines. When any of the facilities used in stages (B) and (C), stops, crude (meth)acrylic acid enters the tank from the unit used in stage (A). After resume the stopped installation crude (meth)acrylic acid, stored in the tank can be fed to the installation used in stage B), and/or installation used at the stage (C).

First, the explanatory notes to the stage (A). At the stage of (A) interact propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular oxygen, using a gas-phase method for the catalytic oxidation, to obtain the crude (meth)acrylic acid. More specifically, the crude (meth)acrylic acid can be obtained by using the method of manufacturing (meth)acrolein from propylene (isobutylene or tert-butanol, in the case of methacrolein) as a starting material in the presence of a catalyst based composite oxides of Mo-Bi, consisting of a Mo-Bi-Fe-Co-Ni-B-Na-Si-O and the like, and the subsequent impact on the obtained (meth)acrolein reaction of gas-phase catalytic oxidation in the presence of a catalyst based composite oxides of Mo-V, consisting of a Mo-V-Sb-Ni-Cu-Si-O and the like, or the effects on propane, as the source material gas-phase catalytic oxidation in the presence of a catalyst based composite oxides of Mo-Bi-Te-based catalyst composite oxides of Mo-Bi-Se or anything like that. In the following descriptions, a method of receiving according to the present invention is illustrated in connection with obtaining acrylic acid as a typical example. However, the method of obtaining a present is Adamu invention is also applicable to obtain methacrylic acid.

The oxidation reaction can be carried out using one-pass method, the method of recycling of unreacted propylene and method of recycling of leaving gas products of combustion. The method of receiving according to the present invention can be carried out using any of these methods.

(1) single-pass method:

One-pass method is a method in which at the initial stage of the reaction mixed gas consisting of propylene, air and steam, is supplied to convert this mixed gas, mainly acrolein and acrylic acid, and then the escaping gas from the initial stage of the reaction is fed to the final stage of the reaction without separation from it of the above reaction products. When submitting leaving gas on the final stage of the reaction, an additional amount of air and steam required at the final stage of the reaction, as a rule, can be introduced together with the output gas from the first reaction stage to the final stage of the reaction.

(2) Method of recycling unreacted propylene:

In the method of recycling of unreacted propylene, the reaction gas containing acrylic acid obtained at the final stage of the reaction, enters the device for collecting the acrylic acid in the form of its aqueous solution, and the portion facing the gas soteriades the unreacted propylene, which is obtained in the device for collection, arrives at the initial stage of the reaction for recycling and reuse it part of the unreacted propylene.

(3) the Method of recycling of leaving gas combustion products:

The way recycling of leaving gas products of combustion is a method in which the reaction gas containing acrylic acid obtained at the final stage of the reaction, enters the device for collecting the acrylic acid in the form of its aqueous solution, and then the entire quantity of the outgoing gas produced from the unit to collect, is oxidized by combustion to convert unreacted propylene or the like contained in the outgoing gas, mainly carbon dioxide and water, and the part thus obtained leaving gas products of combustion is added and recycled in the initial stage of the reaction.

Examples of the reactor used in the oxidation reaction may include Novotrubny reactors with a fixed layer, plate reactors with a fixed layer and a fluidized bed reactor, although they are not limited only to these reactors. Among these reactors Novotrubny reactors with a fixed layer are widely used for the production of acrolein or acrylic acid using the reaction gasof the EIT catalytic oxidation, in which propylene or isobutylene interact with molecular oxygen or gas containing molecular oxygen, in the presence of a catalyst based composite oxides. Novotrubny reactors with a fixed layer are not in any way limited, because these reactors are suitable for use in normal industrial applications.

Acrylic acid can usually be obtained from a gas containing acrylic acid obtained in the oxidation of using any of the following three ways:

(1) a Method of bringing into contact with gas containing acrylic acid, with water, for collecting the acrylic acid in the form of its aqueous solution; extracting acrylic acid from the thus obtained aqueous solution of acrylic acid, using an appropriate extraction solvent; and the subsequent separation of the obtained extract is acrylic acid and the solvent.

(2) a Method of bringing into contact with gas containing acrylic acid, with water, for collecting the acrylic acid in the form of its aqueous solution; distillatory thus obtained aqueous solution of acrylic acid in the presence of an azeotropic solvent in the column for azeotropic distillation for azeotropic selection crude acrylic acid from the bottom of the column; and the following is the removing acetic acid from the resulting crude acrylic acid.

(3) a Method of bringing into contact with gas containing acrylic acid, with an organic solvent, for collecting the acrylic acid in the form of a solution of acrylic acid in an organic solvent, simultaneous separation and removal of it this way, water, acetic acid and the like; and subsequent separation of acrylic acid from the thus obtained solution of acrylic acid in an organic solvent.

Water, acetic acid, an organic solvent, the solvent azeotropic solvent (examples of these solvents may include methyl isobutyl ketone, methyl ethyl ketone, toluene, propyl, ethyl acetate, and mixed solvents of two or more of them) and the like may be separated using conventional distillation columns. As distillation columns can be used in distillation columns typically used in chemical plants that consist of a single tower, or of two or more towers. Inside the distillation column can be provided by a plate or the materials of the nozzle. Plate or the materials of the nozzles used in the distillation column, are not specifically limited, and any conventional plates and the materials of the nozzles can be used in it accordingly. These plates and the materials of the nozzles can use the change in the combination of any two or more kinds of them.

Examples of the plates may include a plate having drain the glass, such as plate bubble cap, a perforated plate, valve plate, the plate SUPERFRAC and saucer MAX-FRAC, and plates without the drain of glasses, such as a plate, with a double thread. Examples of the material of the nozzle can include regular materials nozzles and non-material nozzles. Specific examples of materials of the nozzles may include "SULZER PACKING produced by Sulzer Brothers Limited, "SUMITOMO SULZER PACKING, a product by Sumitomo Jukikai Kogyo Co., Ltd., "MELLAPAK"produced by Sumitomo Jukikai Kogyo Co., Ltd., "GEM-PAK made Grich Inc., "MONTZ-PAK made Montz Inc., "GOODROLL PACKING ", produced by Tokyo Special Wire Netting Co. Ltd., "HONEYCOMB PACK"produced by Nihon Gaishi Co., Ltd., "IMPULSE PACKING produced by Nagaoka Co., Ltd., and "MC PACK"produced by Mitsubishi Chemical Engineering Co., Ltd. Specific examples of irregular materials of nozzles may include "INTERLOX SADDLES produced by Norton Inc., "TELLERETT"manufactured by Nittetsu Kakoki Co., Ltd., "POLE RINGS"produced by BASF AG, "CASCADE MINI-RING"produced by Mass-Transfer, Inc., and "FLEXI-RINGS"produced by Nikki Co.,Ltd.

As a cooling device connected to the distillation column, can be used top azoogleads the heat exchanger (condenser) and ventilation azoogleads exchanger (vent gas condenser), which can be attached to the distillation columns is E. These capacitors usually classified as capacitors that are installed inside the column, and capacitors that are installed outside of the column. The type of condenser and vent gas condenser is not limited specifically. Specific examples of these capacitors may include a vertical fixed tubular-plate capacitors, fixed horizontal tubular-plate capacitors, U-shaped tubular capacitors, capacitors with double tubes, spiral capacitors, capacitors with pyramidal blocks and disc capacitors.

The heat exchangers (reboiler)attached to a distillation column for heating the liquid in its lower part, in General, are classified as reboiler installed inside the column and reboiler installed outside of the column. Type reboiler attached to the distillation column does not specifically limited. Specific examples of reboilers may include vertical fixed tube plate reboiler, horizontal fixed tube plate reboiler, U-shaped tubular reboiler, reboiler with double tubes, spiral reboiler, reboiler with pyramidal blocks, plate reboiler and thin-film evaporative reboiler.

Materials of different nozzles, the hull of the columns of the, reboilers, condensers, ventilation gas condensers, piping, supports, deflection plates (including the top plate), and the like, distillation columns does not specifically limited and can be selected appropriately in accordance with the properties of the respective liquids to ensure the easily polymerizing compounds that should be treated conditions of temperature and anti-corrosion properties. In obtaining (meth)acrylic acid or complex (meth)acrylic esters examples of materials may include stainless steel, such as SUS304, SUS304L, SUS316, SUS316L, SUS317, SUS317L and SUS327, alloys, Hastelloy or the like.

Since acrylic acid is lignopolimering connection, it is preferable that components with low boiling points were removed from the reaction solution by adding thereto an inhibitor of polymerization. Examples of the polymerization inhibitor may include acrylate copper, dithiocarbamate copper, phenolic compounds, and phenothiazine compounds. Specific examples of dithiocarbamates copper may include dialkyldithiocarbamate copper, such as copper dimethyldithiocarbamate, copper diethyldithiocarbamate, dipropylthiocarbamate copper and dibutyldithiocarbamate copper; cyclic alkylenediamine copper, such as atlantajournal honey is, tetramethyldisilazane copper, pentametilenditiokarbamata copper and hexamethylenediisocyanate copper; and cyclic oxidantinduced copper, such as occipitocervical copper. Specific examples of phenolic compounds may include hydroquinone, mackinon, pyragollole, catechol, resorcinol, phenol and cresol. Specific examples of phenothiazine compounds may include phenothiazines, bis-(α-methylbenzyl)phenothiazines, 3,7-dioctyl phenothiazines and bis-(α,α'-dimethylbenzyl)phenothiazines. These compounds can be used individually or in combination of any two or more of them.

The following are explanations to stage (B). At the stage (B) crude (meth)acrylic acid is purified by obtaining (meth)acrylic acid of high purity (hereinafter referred to as the product of (meth)acrylic acid). Stage (B) typically includes a purification step crude (meth)acrylic acid (hereinafter referred to as crude acrylic acid is described as a typical example).

Stage refining of crude acrylic acid:

At the stage of purification of crude acrylic acid components with high boiling points are removed from the crude acrylic acid to obtain acrylic acid of high purity. Examples of components with high boiling points may include aldehydes, such as benzaldehyde and furfural, maleic sour is s, such as maleic anhydride, adducts of acrylic acid Michael or the like. Examples of the Michael adducts may include acrylic dimer, acrylic trimers, acrylic tetramer or the like.

When crude acrylic acid contains aldehydes and/or maleic acid, the crude acrylic acid is preferably pre-treated by any agent to remove aldehydes and/or maleic acid (cite to published applications for patents of Japan No. 2001-58970 and 2001-213839). More specifically, after adding hydrazine powered connection to the crude acrylic acid, for preliminary interaction of aldehydes and/or maleic acids contained in the crude acrylic acid, the crude acrylic acid is preferably subjected to distillation purification. The reaction device used for communicating between aldehydes and/or maleic acid contained in the crude acrylic acid, and hydrazine powered connection, does not specifically limited, provided that it can provide the temperature and time required for communication. Examples of the reaction device may include a reaction device equipped with a stirrer, and the reaction capacity of the tubular type. The reaction temperature preferably is Astola low, to the extent possible, more specifically it is in the range from the melting point of acrylic acid to 50°C. the reaction Time (residence time) is usually not less than 10 min, preferably from 30 minutes to 3 hours.

Examples of hydrazine powered connections can include hydrazine, hydrazine hydrate, phenyl hydrazine, hydrazine sulfate and hydrazine chloride. These hydrazine powered connections may be used in the form of a mixture of any two or more of them. The number of added hydrazine powered connection can be selected appropriately in accordance with the amounts of aldehydes and/or maleic acid, and also with acceptable concentrations of aldehydes and/or maleic acid contained in the acrylic acid of high purity, obtained after distillation.

Preferably hydrazine powered connection directly added to the crude acrylic acid. The molar ratio of added hydrazine powered compound is usually from 0.1 to 2, preferably from 0.5 to 2, more preferably from 0.5 to 1, relative to the total number of aldehydes and maleic acid contained in the crude acrylic acid.

How to add hydrazine powered connections not specifically limited. Since hydrazine powered connection is required for interaction with impurities that must be removed, the time is I stay away from adding hydrazine powered connection to the crude acrylic acid to producing purified (meth)acrylic acid as distillate in the upper part of the distillation column is preferably from 10 min to 5 hours, more preferably from 20 minutes to 3 hours. When the reaction time (residence time) is too short, hydrazine powered connection may not react with impurities in a sufficient degree. On the other hand, when the reaction time (residence time) is too large, there is a risk that the impurities will increase due to the decomposition of the reaction product. For this reason, the reaction time (residence time) is preferably selected from the above range.

In addition, adding hydrazine powered connection aldehydes can be removed from the crude acrylic acid with the use of the mercaptan compounds, such as n-butyl mercaptan, n-octyl mercaptan and n-dodecyl mercaptan. More specifically, the liquid obtained by adding the mercaptan compounds to the crude acrylic acid can pass through the column with resin filled with sulfonic acid cation exchange resin at a temperature of from 20 to 90°C, with volume time velocity (SV) of from 0.1 to 10/hour to remove aldehydes. The passage of liquid through the column with the resin can be carried out using either method downdraft either way with upward flow. Typically, the above agent for removing aldehyde can be used in an amount of from 1 to 8 moles per one mole of the aldehyde, to which is should be removed.

The crude acrylic acid is treated with hydrazine powered connection and/or mercaptans connection can usually be purified in the distillation column by adding a polymerization inhibitor, such as copper acrylate and dithiocarbamate copper. As the polymerization inhibitor can be used the same polymerization inhibitors, which are used in stage (A). Acrylic acid of high purity Argonauts from the top of the distillation column, while components with high boiling points remain in the liquid in the lower part of the column. The distillation method is not limited specifically and can be used different methods of distillation, such as a single distillation and precision distillation. In addition to this procedure, the distillation can be carried out using either a continuous manner or boot method.

At the same time, although the method of purification of crude acrylic acid by distillation explained above, in the present invention can also be applied to a method of purification of crude acrylic acid by crystallization.

Next are presented explanations to stage (C). At the stage (C) of the crude (meth)acrylic acid reacts with alcohols to obtain a complex (meth)acrylic esters. Specifically, stage (C) includes the step of the reaction esteri the requirements, interoperable crude (meth)acrylic acid with an alcohol in the presence of an acid catalyst, and complicated purification step (meth)acrylic ester by carrying out the procedures in a separate installation for concentrating the resulting reaction solution containing the crude complex (meth)acrylic esters, such as extraction, evaporation and distillation. Examples of complex (meth)acrylic esters obtained in accordance with the method of the present invention, may include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and methoxyethyl (meth)acrylate.

Stage esterification reaction:

The alcohols used at the stage of the esterification reaction may be selected from alcohols corresponding to the target esters. Examples of the alcohols may include methanol, ethanol, propanol, isopropanol, n-butanol, ISO-butanol, sec-butanol, tert-butanol, 2-ethylhexyloxy alcohol, 2-hydroxyethyloxy alcohol, 2-hydroxypropionic alcohol and methoxyethylamine alcohol.

Examples of the acid catalyst may include homogeneous acid catalysts and heterogeneous solid acid catalysts. Specific examples of homogeneous acid catalysts may include sulfuric acid is, p-toluensulfonate acid and methansulfonate acid. Specific examples of heterogeneous solid acid catalysts can include strongly acidic cation-exchange resin, activated clay and acid zeolite. Strongly acidic cation-exchange resin may be either porous type or gel type, and degree of cross-linkage is usually from 2 to 16%. Examples of usable industrial products strongly acidic cation-exchange resins can include porous strongly acidic cation exchange resin "PK-208", "PK-216" and "PK-228", produced by Mitsubishi Depending Co., Ltd., and the like.

The esterification reaction can be carried out using well-known methods without any particular limitation. A method for industrial production can be either a boot method or a continuous method. Molar ratio of starting materials used in the esterification reaction, the type and amount of catalyst used, method of interaction, reaction conditions and the like can be selected appropriately in accordance with the types of alcohols used for this. In addition, when the above-mentioned reaction and distillation gas containing oxygen as a polymerization inhibitor may be added to the reactor, distillation column to etomu like to prevent polymerization of the (meth)acrylic acid and complex (meth)acrylic esters, as the reaction products.

Cleaning stage complex (meth)acrylic ester:

The crude complex (meth)acrylic esters obtained in the above esterification reaction, purified using the procedures carried out in a private setting, such as extraction, evaporation and distillation. Distillation column (column purification), suitable for use with the relevant procedures performed in a separate unit can be the same as that described in stage (A). The terms of the applicable procedures carried out in a separate installation, can be selected appropriately in accordance with the molar relationship between the (meth)acrylic acid and alcohol as raw materials used in the esterification reaction, a catalyst used in the esterification reaction, as well as with the corresponding properties of the original materials, side reaction products and complex (meth)acrylic esters. During the above procedures, conducted in a private setting, complex (meth)acrylic esters as the target products are obtained from the upper part of the column for cleaning complex (meth)acrylic ester.

The bottom liquid obtained from the column for purification, contains mainly inhibitor of polymerization and the Michael adducts. Examples of the Michael adducts may include the Michael adducts is, obtained by adding acrylic acid to the above complex acrylic esters, such as complex alkalemia (having 2-8 carbon atoms) esters or complex cycloalkyl esters of acrylic acid, in particular complex β-aryloxypropanolamine esters; adducts of alcohols Michael, in particular complex β-alkoxyamino esters; esters of acrylic dimers, trimers or tetramers; β-hydroxypropionic acid and complex β-hydroxypropionate esters. For this reason, the liquid from the bottom of the column is preferably supplied as a liquid with a high boiling point in the column for the separation of components with high boiling points for retrieval and reuse of these valuable substances.

The following is a description of tank design for temporary storage of crude (meth)acrylic acid. It is preferable that the tank had a capacity capable of storing this amount of crude (meth)acrylic acid, which is produced within 5 to 10 days at stage (A). Crude (meth)acrylic acid obtained in stage (A), directly through a pipeline and/or through the tank at the appropriate stage (B) and (C). Under normal operating conditions, the amount of crude (meth)acrylic acid, stored in the tank, can in a controlled way be reduced to 40-60%. DL is this goal, the working load of each of the stages (B) and (C) can be installed so the amount of crude (meth)acrylic acid produced in stage (A)is balanced with the amount of crude (meth)acrylic acid is used in stages (B) and (C).

In the case where the installation is used in stage (B) or (C)stops because of problems associated with it, the crude (meth)acrylic acid, which must be submitted stopped the installation, temporarily stored in the tank. The time required to repair a stopped setup used in stage (B) or (C)is in the range from one day, at the very least, and up to about 7 days, at most.

The present invention differs in that in the method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters, which is carried out using plants for stages (A), (B) and (C), as well as the tank, this equipment is constructed in such a way that the performance of the setup used in stage (A) (that is, the maximum intake of crude (meth)acrylic acid) is less than the total consumption of plants used in stages (B) and (C) (that is, the maximum consumption amount of raw (meth)acrylic acid).

Due to the above characteristic of the present invention installed, used in stages (B) and/or (C)may require the consumption of an excess of acrylic acid, that is th number, which corresponds to a productivity higher than in stage (A). For this reason, excess crude (meth)acrylic acid, stored in the tank, can be handled appropriately, and it can be consumed and reduced in number without any significant changes in workload setup used in stage (A). As a result, even when the installation is used in stage (B) or (C)stops because of problems associated with it, the installation used in stage (A), can work continuously without any changes in its workload, so it can be prevented the occurrence of any problems with the polymerization caused by the change in workload at the stage (A).

When the performance of the setup used in stage (A)is identical to or greater than the total consumption of plants used in stages (B) and (C)may become difficult suitable treatment of the excess crude (meth)acrylic acid, stored in the tank. The result is to reduce the amount of excess crude (meth)acrylic acid to be reduced workload setup used in stage (A). Preferably the capacity of the plant that is used in stage (A)is not more than 97%, more preferably from 70 to 90%, relative to the mu consumption units, used in stages (B) and (C). When performance setup used in stage (A)is less than 70%, sometimes it can be more desirable to place an additional number of units for stage (A). Performance facilities used at appropriate stages (A), (B) and (C), does not specifically restricted and performance units, used in stage (A), for the production of crude (meth)acrylic acid is usually not less than 30,000 tons per year.

Examples

The present invention is described in more detail using examples, but these examples are only illustrative and are not intended to limit the scope of the present invention.

Example 1:

Device for producing acrylic acid and methyl acrylate containing unit for obtaining crude acrylic acid (corresponding to stage (A); hereinafter referred to simply as "setting A"), a device for producing acrylic acid of high purity (corresponding to stage (B); hereinafter referred to simply as "setting B"), setting to obtain complex acrylic ester (corresponding to a stage (C); hereinafter referred to simply as "setting") and a tank for storage of acrylic acid, is calculated so that the appropriate settings have the following performance. P. and installation (A) consists of novotrubnogo reactor, adsorption columns, the column for azeotropic distillation column for the separation of acetic acid and columns for the production of crude acrylic acid; set (B) consists of the reactor and the column for the purification of acrylic acid of high purity; and installation (C) consists of the reactor, columns for the separation of acrylic acid, extraction columns, columns for the extraction of alcohols, columns for the separation of components with low boiling points and columns for purification of ester.

Installation (A) has a capacity of production of crude acrylic acid 14 tons/hour, the unit (B) is the consumption of crude acrylic acid 6 tons/hour, and installation (C) is the consumption of crude acrylic acid 10 tons/hour. The crude acrylic acid obtained in the setting of (A), temporarily flows into the tank for storage of acrylic acid, and then is supplied from the tank for the storage of acrylic acid in setup (B) and (C) through appropriate piping.

In the setting of (A) aqueous solution of acrylic acid (containing 55 wt.% acrylic acid and 1.5 wt.% acetic acid), obtained from the adsorption column, enters the column for azeotropic distillation. The column for azeotropic distillation operates at a temperature lower part 83°C and the temperature of the upper part 44°C, the pressure in the upper part of the controlled support is conducted on the level of 14 kPa. Since the work of installation (B) must be stopped because of problems associated with it, the supply of crude acrylic acid from the tank into the plant (B) is terminated, but the setup (A) and (C) are continuous. Installation (A) operates at a workload of 100%, and part of the crude acrylic acid produced in the setting of (A), is consumed in the plant (C), whereas the excess crude acrylic acid that must be consumed in the plant (B), is stored in the tank. When installing (B) resumes after 7 days, the amount of crude acrylic acid stored in the tank increases from the initial 50% to 85%.

During continuous operation (A) when the working load 100% (performance obtaining crude acrylic acid 14 tons/hour) installation (B) operates at a workload of 100% (consumption of crude acrylic acid 6 tons/hour), and installation (C) operates at a workload of 100% (consumption of crude acrylic acid 10 tons/hour), so that the amount of crude acrylic acid stored in the tank is reduced to 50%. The working load of the unit (C) is changed to 80%, and when the same operation (C) continues. The result confirms that the problems with the unit (B) is overcome, and the amount of crude acrylic acid stored in the tank is restored (reduced) to a normal level without changing p is the working load setup (A). 3 months after stopping the operation of the plant (B) installation of stop for periodic inspection with the purpose of overhaul and inspection of the internal space of the column for azeotropic distillation (column dehydration). The result confirms that the polymers of acrylic acid in it are not detected.

Comparative example 1:

Is the same procedure as defined in example 1, except that the consumption of crude acrylic acid plant (C) is changed to 8 tons/hour, and other settings have the same consumption as was used in example 1. Since the work of installation (B) must be stopped because of problems associated with it, the supply of crude acrylic acid from the tank into the plant (B) is terminated, but the setup (A) and (C) are continuous. Installation (A) operates at a workload of 100%, and part of the crude acrylic acid produced in the setting of (A), is consumed in the plant (C), whereas the excess crude acrylic acid that must be consumed in the plant (B), is stored in the tank. When the unit (B) is resumed after 7 days, the amount of crude acrylic acid stored in the tank increases from the initial 50% to 85%.

After resumption of the operation of the plant (B) plant (A), (B) and (C) are, respectively, when the working load is 100%. However, as it is in this work these plants may not recover (decrease) the amount of crude acrylic acid, stored in the tank up to the usual level, the working load of the installation (A) is reduced to 70%. After the amount of crude acrylic acid stored in the tank decreases to the normal level, the working load of the installation (A) increases again up to 100% and it works continuously. From the moment in time at which the working load installation (A) is reduced to 70%, the pressure difference between the upper and lower part of the column for azeotropic distillation (dehydration column) gradually increases, and after 2 months of continuous operation (A) becomes impossible. In the overhaul of the column for azeotropic distillation (dehydration column) to inspect its internal space is confirmed that a large number of polymers is detected on plates 1-4 steps.

A method of obtaining a (meth)acrylic acid and complex (meth)acrylic esters, which includes stages:

(A) interaction of propane, propylene or isobutylene and/or (meth)acrolein with molecular oxygen or gas containing molecular oxygen through a gas-phase method for the catalytic oxidation of obtaining crude (meth)acrylic acid;

(B) purification of the resulting crude (meth)acrylic acid with the product of (meth)acrylic acid; and

(C) implementation of vzaimode istia crude (meth)acrylic acid with alcohol to obtain a complex (meth)acrylic esters

if you stop the installation used at any stage (b) and (C)carried out in parallel to each other, the resulting excess crude (meth)acrylic acid is temporarily stored in the tank, and after the recovery operation is stopped installation, crude (meth)acrylic acid, stored in the tank, goes to the used on stage (In), and/or installation used at the stage (C)

however, the performance on (meth)acrylic acid units, used in stage (A), is calculated so that it was lower than the total consumption of (meth)acrylic acid units used in stages (b) and (C).



 

Same patents:

FIELD: chemistry.

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EFFECT: efficient and fast cleaning of distillation column with extraction of valuable substance.

5 cl, 5 dwg, 3 ex

FIELD: chemistry.

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10 cl, 12 ex, 6 tbl

FIELD: organic chemistry, chemical technology, polymers.

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EFFECT: valuable properties of esters.

12 cl, 2 tbl, 7 ex

FIELD: organic synthesis.

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7 cl, 28 ex, 8 tbl

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

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EFFECT: updated technology; increased yield of target products.

38 cl, 14 dwg, 2 tbl, ex

FIELD: organic chemistry, chemical technology, microbiology.

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EFFECT: improved preparing method.

5 ex

FIELD: chemical engineering.

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2 ex

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EFFECT: valuable properties of substance.

1 tbl, 2 ex

The invention relates to an improved method of dewatering solution of formaldehyde containing formaldehyde, water and methanol, including the distillation of the specified solution of formaldehyde in the presence of exciting water connection with obtaining the formaldehyde-containing product that contains significantly less water than the original solution, and use a solution of formaldehyde containing methanol at a molar ratio of methanol to formaldehyde 0.3 to 1.5:1, obtaining the formaldehyde-containing product in the form of a complex with methanol

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FIELD: chemical technology.

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EFFECT: improved method for re-esterification.

19 cl, 28 ex

The invention relates to synthetic esters of mixtures of fatty acids and alcohols to obtain hydraulic oil
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The invention relates to the field of esters of unsaturated acids, particularly to a method of obtaining alilovic esters of 3,3-dimethylpentan-4-OIC acid of General formula

CH2=CHC(CH3)2CH2CO2R (1), where R is alkyl WITH1-C2

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FIELD: chemistry.

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

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

Catalyst and method // 2316396

FIELD: organic synthesis and catalysts.

SUBSTANCE: invention relates to esterification method utilizing organotitanium or organozirconium catalyst and provides catalytic composition useful in preparation of esters, including polyesters, which contains (i) product of reaction between metal M alcoholate or condensed alcoholate selected from titanium, zirconium, and hafnium alcoholates, (ii) alcohols containing at least two hydroxy groups, (iii) 2-hydroxycarboxylic acid, and (iv) base, wherein molar ratio of base to hydroxycarboxylic acid is within the range between 0.01:1 and 0.79:1. Esterification reaction in presence of above catalyst is also described.

EFFECT: avoided yellowness in final product, raised temperature for the beginning of crystallization and crystallization temperature of polyester.

14 cl, 4 tbl, 20 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of chlorine-substituted phenoxyacetic acid esters by the esterification reaction of corresponding acid with (C7-C9)-alcohol of normal structure of isomers, or in the combination. The esterification reaction is carried out in the mole ratio alcohol : acid = (1.1-1.75):1.0 by step-by-step increasing the temperature process. At the first step the process is carried out at the boiling point of azeotrope alcohol : water depending on the residual pressure value generated in the system for separation of the main mass of formed reaction water followed by increasing temperature by 20-60°C for the complete termination of the esterification reaction. The process can be carried out in the presence of catalytic amounts of mineral acids 0.01-0.03 wt.-% of the reaction mass. Invention provides high quality and high yield of the end product.

EFFECT: improved method of synthesis.

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of saturated aliphatic carboxylic acids with stable carbon isotopes (1-13C). Method involves the hydrocarboxylation reaction of α-olefins with carbon monoxide (13CO) and water at temperature 100-170°C and under pressure not exceeding 5 MPa in the presence of a solvent and catalytic system containing palladium compound as complex PdCl2(PPh3)2 and triphenylphosphine PPh3 taken in the ratio from 1:2 to 1:100, respectively. Synthesized carboxylic acids can be used as diagnostic test-preparations in medicine practice and in criminology, scientific investigations and in other fields. Invention provides synthesis of enanthic acid and caprylic acid labeled by stable carbon isotope 13C at position 1 for a single step, to increase yield of acids as measured for isotope raw, to decrease cost price of acids and to obtain derivatives of (1-13C)-caprylic acid - (1-13C0-caprylate sodium and (carboxy-13C)-trioctanoine.

EFFECT: improved methods of synthesis.

9 cl, 6 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for synthesis of carboxylic acid esters that are used as components of lacquered resins and components of paint-and varnish materials, especially, as plasticizer for plastics. Method involves interaction of di- or polycarboxylic acids or their anhydrides with alcohols wherein reaction water is removed by azeotropic distillation with alcohol, and liquid removed from reaction by azeotropic distillation is replaced with alcohol completely again. The improvement of periodic method used in synthesis of esters provides enhancing yield of the end product and reducing the reaction process time.

EFFECT: improved method of synthesis.

5 cl, 4 ex

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