This application claims the benefit of priority based on the 25th Korea Patent Application No. 10-2016-0158616 November 2016 and April, all information disclosed in the literature of the Korea patent application are included as part of the specification.

The present invention is a (meth) relates to a continuous method and apparatus for recovering acrylic acid.

Technology - which is the background of the invention ί

(Meth) acrylic acid is usually produced by compounds such as propane, propylene, (meth) acrolein by the method for gas-phase oxidation reaction in the presence of a catalyst. For example, the propane in the presence of a suitable catalyst in the reactor and propylene round is by the vapor phase oxidation banung (meth) through an arc the lane (meth) being jeonhuin to acrylic acid, (meth) acrylic acid, unreacted propane or propylene in the reactor, the rear end (meth) the gas mixture is obtained containing an arc lane, organic by-products with an inert gas, carbon dioxide, water vapor, and the reaction (acetic acid, low-boiling by-products and high boiling point by-products, etc.).

The (meth) acrylic acid-containing gas is contacted with absorbent heunhap solvent from the (meth) acrylic acid absorption column is recovered as (meth) acrylic acid aqueous solution. Then, the (meth) acrylic acid is insoluble gas stripping (meth) acrylic acid is recycled to the synthesis banung, some of which is converted to harmless gas is burned and discharged. In addition, the (meth) acrylic acid aqueous solution is obtained by extraction, distillation and purified (meth) acrylic acid.

On the other hand, in order to improve such a (meth) acrylic acid recovery efficiency, the various methods for controlling the process conditions such as process or procedure has been proposed. Among them, (meth) to obtain a (meth) supplying a portion of the acrylic acid aqueous solution by extraction column and using a hydrophobic solvent, the water content decreases (meth) acrylic acid extract, and the weight balance obtained in the acrylic acid absorption column, the extract solution and the absorption how to distillation with a (meth) acrylic acid aqueous solution remaining solution not fed to the extraction column of the obtained in the tower is known.

Further, in the absorber stop the low-concentration (meth) acrylic " in the aqueous solution containing the acid leakage to come selectively to the absorber bottoms , to obtain a high concentration of (meth) acrylic acid aqueous solution, standing, a low concentration of (meth) acrylic acid solution emanating from the absorber stop is supplied to the extraction column, and using a hydrophobic solvent, to obtain the water content sodoen (meth) acrylic "acid extract and the weight balance, distilled azeotropically by supplying the high-concentration (meth) acrylic acid aqueous solution with (meth) acrylic acid extract to the distillation column by this known method to reduce energy consumption.

However, the (meth) known for the continuous recovery of the acid method

(Meth) to increase the amount of the hydrophobic solvent in the extraction column in order to increase the extraction rate of the acrylic acid, the amount of the azeotropic solvent to be supplied to the subsequent water separation column feed end and the mid-priced, the water separation column top discharge liquid within the (meth) acrylic acid content Since this to be lower water and must maintain a constant solvent amount to be supplied to the water separation column to azeotropic distillation of the solvent, the solvent amount used is introduced into the reflux to the water separation column is reduced, the water separation column within a gas / liquid behavior to thereby change occurs. Thus, while drying the water separation column top tray, thereby reducing the separation efficiency of the water separation column, (meth) there is a limit to a reduced recovery rate of the acrylic acid.

[Contents of the present invention;

[Problems to be solved;

The present invention provides a high (meth) acrylic acid recovery, yet can be secured, and more (meth) continuous method for recovering acrylic acid which can ensure an improved operating stability.

In addition, the present invention is to provide a device capable of using the continuous recovery of (meth) acrylic acid.

[Solving means of a problem]

The present invention, (meth) contacting the acid Malmo synthetic reaction of (meth) acrylic acid, water, a heunhap gas containing the organic by-products and water vapor (meth) from the acrylic acid absorption column produced by 30 to 70% from the top of the absorption tower and low-concentration (meth) acrylic acid solution discharged from any one point corresponding to, to obtain a high concentration of (meth) acrylic acid solution discharged to the bottom of the absorption tower;

The step of contacting the extraction solvent comprising a hydrophobic organic solvent in the low concentration (meth) acrylic acid aqueous solution of (meth) acrylic acid extraction column (extraction of methacrylic acid;

To obtain a distillate by distilling the obtained (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution of the water separation column; And

The (meth) acrylic acid extract, and high-concentration (meth) by a feed (feed), except for distilled water in the acrylic acid aqueous solution heated in acetic acid separating column (meth) acrylic acid to obtain a; includes; .

The (meth) weight ratio of extraction solvent to the water in the feed to the step of extracting a low-concentration acrylic acid (meth) acrylic acid aqueous solution is more than 2.7, the acetic acid . Flowing into the separating column the (meth) acrylic acid extract, and high-concentration (meth) feed (feed), except for distilled water in the acrylic acid aqueous solution is 0.1 to 10 parts by weight of acetic acid 0 / 0 acrylate, 60 to 99 parts by weight 0 / 0 include and residual organic by-products to, (meth) provides a continuous method for recovering acrylic acid.

The present invention is a (meth) being provided with a heunhap gas inlet through which a gas mixture is supplied which comprises a (meth) acrylic acid and organic by-products and water vapor generated by the synthesis banung of acrylic acid, and obtained by the above heunhap gas and water contact low concentration (meth) the low concentration of (meth) acrylic acid aqueous solution outlet is acrylic acid aqueous solution is discharged is provided in one point corresponding to 30 to 70% from the top, and high-concentration (meth) acrylic acid aqueous solution outlet is a (meth) acrylic acid having at the bottom hop water tower (100);

The (meth) acrylic acid extract obtained by the contact of the absorber 100, a low concentration of (meth) acrylic acid aqueous solution outlet and the solution transfer line 103, a ^ to associated solution inlet port, the inlet (meth) acrylic acid aqueous solution and the extraction solvent of the extract outlet, and the weight balance is discharged, the discharge outlet having a weight balance which is a (meth) acrylic acid extraction column 200;

. It is connected via the extract outlet and the extract feed line 203 of the extraction tower 200, the (meth) acrylic acid absorption tower 100 of the (meth) acrylic acid aqueous solution , the outlet and the feed line 102 feeds (feed is connected via a ) inlet, and a feed (feed) a water separating column (300 having a bottom outlet is discharged, except for the distillate from the top distillate is the discharge of the inlet feed (feed) inlet and outlet feed (feed)); And

Connected through a bottom outlet and a transfer line 303 of the water separation column 300, the feed (feed) inlet and, obtained by the heating of the incoming feed (feed), acetic acid outlet and a (meth) (meth that acrylic acid is discharged ) includes the acid separating column (500) having an acid outlet,

Feed (feed) is the weight ratio of extraction solvent to water in the low-concentration (meth) acrylic acid aqueous solution supplied to the (meth) acrylic acid extraction column 200 is at least 2.7, the inlet to the acid separation column is acetic acid 01 to 10 parts by weight 0 / 0 , acrylic acid increased to 60 to 99 0 / 0 , (meth) is operated to include the by-products and residual organic provides a continuous system for recovering acrylic acid.

According to the specific implementation of the invention below (meth) it will be in more detail described with reference to a continuous method and apparatus for recovering acrylic acid. .

In the meantime, unless expressly stated in this specification, some terms are defined with the following meanings:

In this specification, "(meth) acrylate, 1 means any means that may be used in the popular name of acrylic acid (acrylic acid), methacrylic acid (methacrylic acid) or a common compound. '

It referred to herein, "(meth) acrylic acid-containing gas mixture, also is known as a heunhap gas that may be generated when manufacturing the (meth) acrylic acid by gas-phase oxidation banung. That is, the present, according to one embodiment of the invention, propane, propylene, butane, butylene i-, t- butylene, and (meth) arc in the lane of one or more compound ( "compound material") selected from the group consisting of wherein the method of banung phase oxidation in the presence of a catalyst (meth) acrylic acid-containing gas mixture can be obtained. In this case, the (meth) acrylic acid-containing heunhap gas, (meth) acrylic acid, the unreacted starting materials, (meth) arc the lane, an inert gas, carbon monoxide, carbon dioxide, water vapor and various organic by-products (acetate, low boiling point by-products and high boiling point by-products, etc. ) it can be included and the like. Here, "low boiling point by-products" (light ends) or 1 as one type of high boiling point by-products "(heavies) means the by-products that may be generated during the manufacturing and recovery process of the target (meth) acrylic acid, which is called a molecular weight of (meth) than acrylic acid small or large is referred compounds.

In this specification, the "feed" (feed) shall mean as meaning a liquid mixture containing the solute (solute) to be extracted, the extraction solvent (extraction solvent) not having a solute and availability having a soluble relative to other components ( It can be water heunhap of inert material). Here, the solute by mass transfer phenomena Applying the extraction solvent in the feed is dissolved in the extraction solvent from the feed. Thus, a considerable amount of solute dissolved in the extraction solvent is to form an extract phase (extract), the feed has lost a significant amount of the solute is formed in the weight after image (raffinate).

In this specification, "(meth) acrylic acid aqueous solution" is a (meth) acrylic acid as a feed, for example, be obtained by the method of contacting the above-mentioned (meth) acrylic acid-containing gas and water heunhap.

Terminology used herein is simply intended to refer to a specific embodiment and are not intended to limit the present invention. And, as used herein the singular forms also include the plural forms a phrase that does not represent a meaning clearly contrary in this way. Also, the meaning of "include" used in the specification, except for the addition of specific characteristics, regions, integers, steps, operations, elements, or, and refine the components, other specific characteristics, regions, integers, steps, operations, elements, or components It is not that.

Or less, so that the invention may be modified in ordinary skill in the art to readily practice the invention all belong, it will be described in detail in the implementation examples of the present invention with reference to the accompanying drawings. However, the invention is not be implemented in a number of different forms and limited only of embodiments described herein.

I. (meth continuous method for recovering acrylic acid 1

According to one embodiment of the invention,

(Meth) which is brought into contact heunhap gas containing (meth) acrylic acid and organic by-products and water vapor generated by the synthesis banung of acrylic acid (meth) with water in the acrylic acid absorption column corresponding to 30 to 70% from the top of the absorption tower and low-concentration (meth) acrylic acid solution discharged from a point, to obtain a high concentration of (meth) acrylic acid solution discharged to the bottom of the absorption tower;

Extracting a is contacted with an extraction solvent comprising a hydrophobic organic solvent to the low concentration of (meth) acrylic acid aqueous solution of (meth) acrylic acid in the extraction column (meth) acrylic acid;

To obtain a distillate by distilling the obtained (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution of the water separation column; And.

The (meth) acrylic acid extract, and high-concentration (meth) by a feed (feed), except for distilled water in the acrylic acid aqueous solution heated in acetic acid separating column (meth) acrylic acid to obtain a; includes;

The (meth) increased the ratio of extraction solvent to the water in the feed to the step of extracting the acid a low concentration of (meth) acrylic acid aqueous solution is more than 2.7, (meth) flowing into the acid separation column acrylic acid extract, and a high concentration of (meth) acrylic acid feed (feed), except for distilled water in the aqueous solution is from 0.1 to 10% by weight ethyl acrylate, 60 to 99 weight 0 / 0 containing organic by-products and the residual,

(Meth) may provide a continuous method for recovering acrylic acid.

The present inventors have found that (meth) In the research process for the continuous method for recovering acrylic acid, disclosed in the previous supply the (meth) acrylic acid aqueous solution in the extraction column using a hydrophobic solvent, to obtain a (meth) acrylic acid extract by distilling the said extract (meth) room for recovering acrylic acid , when method increases the amount of the hydrophobic solvent in order to increase the extraction rate was confirmed that a number of problems such that the recovery rate by increasing the amount of acetic acid to the lower end of the water separating column lowered occurs.

Thus, it continued research by the present inventors. Result, (meth) as shown in Figure 1 for introducing the acetic acid separation step after the distillation process of acrylic acid, by operating the water separation column from low temperature to minimize the content of the acetic acid distilled water, remaining in the bottom of the water separation column it can be reused by recovering acetic acid from the acid separation column was confirmed more economical and reliable operation of the continuous process is possible.

Note the following, Fig. 1, description will now be given of each step that can be included in embodiments of the invention.

Absorption process

First, in the continuous method for recovering the one (meth) according to an embodiment of acrylic acid, (meth) produced by the synthesis banung of acrylic acid (meth) acrylic acid, a mixed gas containing the organic by-products and the vapor of (meth) acrylic acid absorption tower in the contacting with water

(Meth) containing the step for obtaining the aqueous acrylic acid solution, herein absorption process means a process for obtaining this (meth) acrylic acid aqueous solution.

More specifically, the (meth) Synthesis banung of acrylic acid is carried out in a manner that the oxidation reaction of at least one compound selected from the group consisting of propane, propylene, butane, iso-butylene, and (meth) arc the lane under the vapor phase catalytic It can be. In this case, the gas-phase oxidation reaction is conducted under gas phase oxidation reaction conditions and unggi half of conventional structures: The number 1 has. The vapor that the catalyst also typically in the oxidation reaction. It may be used, for example, be a catalyst or the like to be used as disclosed in the Republic of Korea Patent Registration No. 0349602 and No. No. 037 818. In addition to the vapor of (meth) oxide banung the (meth) acrylic acid-containing heunhap gas is the desired product produced by acid, US banung starting materials, the intermediate, (meth) arc lane, inert gases, carbon dioxide, water vapor, and various organic by-products It may contain the (acetate, low boiling point by-products and high boiling point by-products, etc.).

And, referring to FIG. 1, the (meth) acrylic acid aqueous solution of (meth) by supplying an acrylic acid-containing heunhap gas (1) (meth) acrylic acid absorption tower 100 and brought into contact with an absorption solvent, water, (meth) acrylic acid this can be obtained in the form of an aqueous solution dissolved.

Here, (meth) the type of acrylic acid absorption tower 100 may be determined in view of such the heunhap gas 1 and the contact efficiency of the absorbing solvent, for example an absorption tower, multi of packed column type (packed column type) stage tray type (multistage tray type) absorber may be eu the packed column type absorption tower lashing ring (rashing ring) therein, polls (pall ring), saddle (saddle), gauze (gauze), Structure of the the filler may be applied, such as packing (structured packing).

And, in view of the efficiency of the absorption step, the heunhap gas 1 can be fed to the bottom of the absorption tower 100, the absorbing solvent including water may be supplied to the upper portion of the absorption tower 100.

The absorption solvent may comprise water, such as may deutmul, deionized water may include a water circulating step is introduced from the other process (for example, extraction processes and / or water recycled from the distillation step). Also, the absorption solvents, (e.g. acetic acid), organic by-products in trace amounts introduced from other processes may be included. However, (meth) is preferably such that, taking into account all of the acrylic acid absorption hyoeul, absorbing the solvent (in particular the circulation process water) to be supplied to the absorber (100) includes less than 15% by weight of organic by-products Ah.

On the other hand, (meth) acrylic acid absorption tower 100 includes a (meth) acrylic acid of ungchuk conditions and taking into account the water content, etc. of the saturated water vapor pressure, 1 to 1.5 bar or the first internal pressure to 1.3 bar, 50 to 100 ° C or 50 to 80 ° can be operated under the temperature inside the C.

On the other hand, through the absorption step, the (meth) acrylic acid in which a point corresponding to 30 to 70% from the top of the absorber 100 has a (meth) acrylic acid is about 50 weight 0 / 0 less than or equal to the low concentration of (meth) acrylic acid aqueous solution is withdrawn, the bottom is a (meth) the high concentration of (meth) acrylic acid aqueous solution ¾ arc is not less than about 50% is discharged. In addition, the top of the absorber is a biung condensable gas (meth) acrylate is degassed and discharged.

Then, the low-concentration and high-concentration (meth) acrylic acid aqueous solution obtained is, as shown in Figure 1, a high concentration of (meth) acrylic acid aqueous solution, or fed to the transfer line 102, the water separation column 300 via a low-concentration (meth) acrylic acid aqueous solution transferred via line 103, a (meth) acrylic acid can be supplied to the extraction column (200).

On the other hand, (meth) at least a portion of non-condensable gas discharged to the top of the acrylic acid absorption tower 100 for recovering the organic by-products (particularly acetic acid) are included in biung condensable gases

It can be supplied to the process, and the rest may be discarded as a waste gas is supplied to the incinerator. That is, according to one embodiment of the invention, contacting the biung condensable gas and the absorption solvent, a step of recovering the acetic acid contained in the non-condensable gas can be carried out.

Contacting said non-condensable gas and the absorption solution may be performed in nitric acid absorption tower 150. At this time, for effective acid absorption, acid absorption tower 150 can be operated at a pressure of 1 to 1.5 bar, preferably from 1 to 1.3 bar, the internal temperature from 50 to 100 ° C, preferably from 50 to 80 ° can be adjusted such that the C. In addition, the specific operating conditions of the nitric acid absorption tower 150 may be in accordance with the Republic of Korea Patent Publication No. 2009-0041355.

At this time, the upper portion of the acetic acid absorption tower 150 to the lower portion of the absorption solvent (process water) is supplied, acetic acid absorption tower 150 for absorbing the acid may be an aqueous solution containing acetic acid discharged. In addition, the acetic acid-containing aqueous solution is supplied to the upper portion of the (meth) acrylic acid absorption tower 100, it can be used as the absorbing solvent. Furthermore, the condensable gas biung the acetic acid stripping is circulated to the synthesis banung process of (meth) acrylic acid can be reused.

Extraction Process

On the other hand, the continuous method for recovering the one (meth) according to an embodiment of acrylic acid is brought into contact with an extraction solvent comprising a hydrophobic organic solvent to the low concentration of (meth) acrylic acid aqueous solution of (meth) from acid extraction column (meth) extracting acrylic acid the step of includes.

(Meth) from acid extraction column 200, the feed (feed) the low concentration of (meth) acrylic acid aqueous solution is in contact with the extracting solvent, a significant amount of (meth) acrylic acid is soluble extract (extract) and (meth) a significant amount of acrylic acid It is lost with each discharge weight balance (raffinate). At this time, the low concentration of (meth) acrylic acid aqueous solution of (meth) to be either discharged at a point corresponding to 30 to 70% from the top of the acrylic acid absorption tower (meth) acrylate, 1 to 50 parts by weight 0 / 0 , water 50 to 95 weight 0 / 0 may include organic by-products and of the residual amount.

And, in the extraction column 200, a relatively light merchant extract is obtained through the top outlet, the dealer relatively heavy weight balance is obtained through the bottom outlet of the extraction column. The weight balance, before being discharged from the extraction tower 200, is present in the amount of a level value to the lower value range of the extraction column conditions, and some of which is fed to the lower outlet of the extraction column.

In this manner, through the method of contacting a low-concentration (meth) acrylic acid aqueous solution and the extraction solvent in the extraction tower 200, and most of the water contained in the low concentration (meth) acrylic acid aqueous solution can be removed. It can lower the processing load of the distillation process a subsequent process, it is possible improve the energy efficiency of the overall process. Furthermore, by reducing the processing load of the distillation process, there are (meth) acrylic acid in the polymerization banung that may occur during distillation is minimized, a more improved (meth) acrylic acid recovery efficiency can be secured. '

On the other hand, the extraction solvent is fed to the extraction column (200) comprises a hydrophobic organic solvent, and may include organic by-products. Specifically, the extraction solvent is benzene (benzene), a toluene (toluene), and xylene (xylene), n- heptane (n-heptane), cycloheptane (cycloheptane), cycloheptene (cycloheptene), 1- heptene (l -heptene) ' , : ethyl-benzene (ethyl-benzene), methyl-cyclopentane nucleic acid (methyl-cyclohexane), n- butyl acetate (n-butyl acetate), isobutyl acetate (isobutyl acetate), isobutyl acrylate (isobutyl acrylate), n- propyl acetate (n-propyl acetate), isopropyl acetate (isopropyl acetate), methyl isobutyl ketone (methyl isobutyl ketone), 2- methyl-1-heptene (2-methyl-l-heptene ), 6 -methyl-1-heptene (6-methyl-l-heptene ), 4- methyl-1-heptene (4-methyl-l-heptene), 2 _ ethyl-1 haeksen ( 2 -ethyl-l-hexene), ethyl cyclopentane (ethylcyclopentane), 2- methyl-1-haeksen (2-methyl-l-hexene ), 2,3- dimethyl cyclopentane (2,3-dimethyIpentane), 5- methyl-1-haeksen (5-methyI- l-hexene), and isopropyl-ether (isopropyl-butyl-ether) - butyl Luer binary one member selected from the group " may include at least a hydrophobic organic solvent.

Then, the increase ratio of the extraction solvent to the water in the (meth) the low concentration of (meth) acrylic acid aqueous solution supplied to the step of extracting the acrylic acid may be 2.7 or more, preferably 3.0 to 5.0 or more, more preferably 3.0. Likewise

As the control the amount of the extraction solvent at the extraction step, it can be increased to reflux (reflux) of the solvent in the subsequent distillation process in which (meth) further increase the recovery efficiency of acrylic acid.

In the extraction process, the low-concentration (meth) the weight ratio of extraction solvent to water in the aqueous acrylic acid solution is less than 2.7, the (meth) acrylic acid is not preferable extraction efficiency is lowered. Then, the weight ratio of extraction solvent to water in the low-concentration (meth) acrylic acid aqueous solution if 5.0 is exceeded, the (meth) but extracting the higher the weight ratio of extraction efficiency of the solvent in water in the acrylic acid aqueous solution can be enhanced, the subsequent in the distillation step (meth) may be the loss of acrylic acid increases, undesirable increased to reflux (reflux) of the solvent is excessively to prevent this.

In addition, the extraction tower 200 to the liquid - there is a conventional extraction column of the liquid contact method may be used without particular limitation eu, for example, reciprocating the rate column in the Karr type (Karr type reciprocating plate column), the rotation - a disk-shaped column (rotary-disk contactor), Scheibel columns and Kuhni columns, spray extraction tower (spray extraction tower), mogul jujul tower (packed extraction tower), Phelps mogul column (pulsed packed column) can deungeol eu

Thus through the same extraction process, to the upper portion of the extraction column 200 has a (meth) acrylic acid extract is discharged, the discharged water the extract is fed to the separation column 300 through a feed line 203. The And, a lower portion of the extraction column 200 is the weight balance has been discharged, the discharged weight balance is recycled to the process feed, onto the separating tank 350 through transfer line 201. The

In this case, the extract contains not only the desired compound of (meth) acrylic acid, it may be included in the extraction solvent, water and organic by-products. According to the embodiment, in a steady state and a stable operation is performed, the extract has a (meth) acrylate, 5 to 13 parts by weight 0 / 0 , the extraction solvent 85 to 93 parts by weight 0 / 0 , water, 0.01 to 2 parts by weight 0 / 0 , and it may include organic by-products of the remaining amount. That is, most of the water contained in the (meth) acrylic acid aqueous solution via the extraction process may be recovered as a weight balance. Thus, as most of the water recovered from the extraction process, a distillation process

Reducing the operating pressure can reduce the energy consumption. And, can be a distillation conditions mitigated by this, it is possible to obtain the (meth) acrylic acid recovery efficiency improvement of the operation stability and the like with (meth) acrylic acid from polymerization banung the distillation process can be minimized.

Then, the weight balance which is obtained from the extraction tower 200 may be the most can be made of water, is included fails to be extracted (meth) acrylic acid and organic by-product portion. However, according to one embodiment of the invention, the weight balance, the concentration of 15 weight 0 / 0 or less or αι to 5% by weight it can be very low (meth) acrylic acid, in the absorption step and the extraction step ( meth) acrylic acid loss can be minimized.

Distillation

Then, the continuous distillation of a method for recovering the one (meth) acrylic acid according to the embodiment is thus obtained (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution of the water separation column and a step to obtain a distillate.

Then, at the step to obtain the distillate, at least any one of an operating temperature of not ¾ which fall within 10% from the bottom of the water separation column may be a 40 to 8 (rc, preferably from 40 to 7 (rc. The in obtaining a distillate, a (meth) acrylic acid extract, and high-concentration (meth) organic by-products (acetic acid) contained in the acrylic acid aqueous solution is not distilled, and adjusted to distillation only water as a solvent, organic by-products (acetic acid) is to be described later it is desirable to separate from the acetic acid separation column, to control as the temperature of the at least one point that fall within 10% from the bottom of the water separation column, and the need for this.

In addition, the one embodiment of water separation column 300 and the top of the pressure from atmospheric pressure to 20 torr, the operating temperature of the bottom 40 to 100 ° may be C.

Then, the continuous method for recovering the one (meth) according to an example acrylic acid in order that can be made efficient distillation, the extract and a high concentration of (meth) acrylic acid aqueous solution of 25 to 75% from the top of the total number of stages of the water separating column prepared any one that corresponds to, it is preferable to feed in either one or for the 40 to 60%.

75% from the top of the said extract, and a high concentration of (meth) acrylic acid aqueous solution of the water separation column 300. The If supply to a point beyond the portion of the extract, and high-concentration (meth) water minutes included in the acrylic acid aqueous solution ratap water and extract to be recovered in the upper discharge liquid solvent is to be included in the lower discharge liquid of the water separation column, so it must be reunited in acetic acid separation column may issue the problem did not facilitate the operation. In addition, when the extract is supplied to the point of less than 25% from the top of the water separation column, the acrylic acid recovery of the concentration of the acid increases the water contained in the water separation column separating column top discharge liquid can be lowered.

In addition, the water supplied to the separation column 300, a (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution is brought into contact with an azeotropic solvent is introduced into the top, while heating to the proper temperature is achieved distilled by evaporation and ungchuk .

In this case, the extract liquid and highly concentrated (meth) (meth) acrylic acid aqueous solution of acrylic acid to the remaining components in order to efficiently separate from (e. G., Water, acetic acid, solvent extraction and the like), the distillation is azeotropic distillation to be performed is preferred.

The solvent to be applied to sangki azeotropic distillation can do this the water and acetic acid and the azeotropic and (meth) acrylic acid and does not form an azeotropic " it is preferably a hydrophobic azeotropic solvent eu and the hydrophobic azeotropic solvents include (meth) lower than the acrylic acid boiling point (e.g. 120 ° C or less, or from 10 to 120 ° C, or from 50 to 120 ° to have a boiling point of C) is preferred.

Specifically, the hydrophobic azeotropic solvents benzene (benzene), a toluene (toluene), and xylene (xylene), n- heptane (n-heptane), cycloheptane (cycloheptane), cycloheptene (cycloheptene), 1- heptene ( 1-heptene), ethyl-benzene (ethyl-benzene), methyl-cyclopentane acid (11 ^ 1 1 [7101 & 1), 1-butyl acetate (n-butyl acetate), isobutyl acetate (isobutyl acetate), isobutyl acrylate (isobutyl acrylate), n- propyl acetate (n-propyl acetate), isopropyl acetate (isopropyl acetate), methyl isobutyl ketone (methyl isobutyl ketone), 2- methyl-1-heptene (2-methyl-l- heptene), 6- methyl _1_ heptene (6-methyl-l-heptene), 4 - methyl-1-heptene ( 4 -methyl-l-heptene), 2- ethyl-1-haeksen ( 2 -ethyl-l- hexene), ethyl cyclopentane (ethylcyclopentane), 2 - methyl-1-haeksen ( 2 - methyl-l-hexene), 2,3- dimethyl cyclopentane (2,3-dimethylpentane), 5- methyl-1-haeksen (5 -methyl-l-hexene) and isopropyl t-butyl-ether (isopropyl-butyl-et her) may be daily for one or more selected from the group consisting of.

And, in view of the production efficiency, according to the continuous process, the hydrophobic azeotropic solvent is preferably the same as the extraction solvent in the> process Ex. Thus, when the type of the solvent such as the extraction process and the distillation process is used, the distillation of the water separation column 300 at least some of the solvent recovered by the phase separation tank (350) is a (meth) acrylic acid extraction column 200, is supplied can be reused as an extraction solvent.

Through such a distillation step, the feed of (meth) acrylic acid remaining ingredients, except water, are discharged to the upper portion of the separating column (300) with the azeotropic solvent, the (meth) acrylic acid is discharged to the lower portion.

At this time, the upper liquid discharge of the water separation column 300 is supplied to the separating tank (350) can be re-used after predetermined processing. Here, as a device for separation by a separation tank 350 is gravity or centrifugal force, a liquid that is immiscible with each other, relatively (e. G., Organic phase) light liquid into the top of the separating tank 350, relatively S heavy liquid (e.g., water) may be returned to the lower portion of the separating tank (350).

For example, the weight balance discharged from the extraction tower 200, the upper discharge liquid and, above a water separating column 300 can be separated into a water phase comprises an organic phase and water containing the solvent in the separating tank (350) have. Here, the separated organic phase is fed to the upper end of the water separation tower 300 may be used as the azeotropic solvent / and, if desired, at least a portion of the organic phase is fed to extraction column 200 it may be used rosseodo extraction solvent . And is supplied at least in part Al (meth) acrylic acid absorption tower 100 of a separate award from the separation vessel 350 may be used as an absorption solvent, a part may be treated in the waste water. In addition, the award there may be some acid is included, the concentration of acetic acid contained in the water phase can vary, depending upon the type of the azeotropic solvent and the reflux ratio.

On the other hand, the above-mentioned (meth) acrylic acid aqueous solution while passing through the (meth) acrylic acid absorption tower 100, the extraction tower 200, and a water separating column (300) or the like, contained in the aqueous solution

(Meth) acrylic acid at least a portion of the can to form a dimer or oligomer. To this (meth) minimize the polymerization of acrylic acid, a conventional polymerization inhibitor, the water separation column 300 may be added.

Acetic acid separation step

On the other hand, the continuous method for recovering the one (meth) according to an embodiment of acrylic acid, by heating the feed (feed), except for distilled water in the (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution in the acetic acid separating column (meth) O is included to obtain a H rilsan.

(Meth) feed (feed) other than the acrylic acid extract, and high-concentration (meth) acrylic acid aqueous solution in distilled water is fed to the acetic acid separation column 500 via the feed line 303. And to afford the acetic acid separation column by using a reboiler (reboiler) in the bottom of supplying heat, and recovering acetic acid from the top outlet, excluding the recovered acid (meth) acrylic acid through the bottom outlet.

Flowing to the acid separating column (meth) acrylic acid extract, and a high concentration

(Meth) feed (feed), except for distilled water in the acrylic acid aqueous solution is 0.1 to 10% by weight, acrylic acid 60 acetic acid " includes to 99% by weight and a residual organic by-products, it may further include an extraction solvent or water.

At this time, in order to enable an efficient acid separation can be achieved, the feed is supplied to any one corresponding to any one, or 50 to 70% for the 40 to 70% from the top of the total number of stages of the acid separating column prepared it is desirable.

In addition, the one ' embodiment of acetic acid separation column 500 has a top temperature of 40 to 90 ° may be a C, the lower temperature of 50 to 100 ° may be C. Intended to mean at least one point that fall within 10% from the top of the acid separation column "top" of the tower acid separating column, "lower" refers to a at least one point that fall within 10% from the bottom of the acid separation column do.

Further, it is possible to control the pressure in choesangdanwa atmospheric pressure to 20 torr for effective distillation of the feed of the acid separating column.

On the other hand, use of (meth) acrylic acid extract, and a high concentration in the acetic acid separating column

(Meth) top discharge liquid by heating the feed (feed), except for distilled water in the aqueous acrylic acid solution obtained from the top are input to the (meth) acrylic acid extraction column it may be recycled.

In addition, the (meth) acrylic acid extract, and high-concentration (meth) obtained by a feed (feed), except for distilled water in the acrylic acid aqueous solution heated in acetic acid separating column (meth) acrylic acid is acetic acid to 4 parts by weight 0 / 0 or less, or 3 wt. 0 / 0 can be included as described below.

Thus, the one embodiment the (meth) continuous method for recovering acrylic acid is acetic acid are collected separately with the acid separation process, a (meth) being recycled is supplied to the acrylic acid extraction column, can provide more cost-effective and operational in a stable continuous process.

And, there may be included such as acetic acid removal, the (meth) lower discharge liquid of the tower 500, in addition to acrylic acid (meth) acrylic acid polymers of high boiling point by-products such as, the polymerization inhibitor. Therefore, acetate, separating bottoms discharged liquid to the high boiling point of 500, if necessary , a step of separating the high boiling point by-products contained in the by-product separation column (400), said lower discharge liquid supplied to be carried out by adding . Then, the number of times over the course crude (meth) acrylic acid (CAA) can be obtained in a higher purity through an additional crystallization step (methoxycarbonyl. Root) acrylic acid (HPAA). At this time, such as the high boiling by-products minutes step and the crystallization step is a step can be carried out under conventional conditions, process conditions, etc. are not specifically limited to let. "

In such a (meth) acrylic acid recovery method, the steps described above can be carried out in the organic and continuous. And, in addition to the above-described process steps that may be performed before or after or at the same time as each of the conventional steps may be operated it is further included.

II. (Meth) acrylic acid in a continuous recovery unit

According to another embodiment of the invention,

(Meth) and a gas inlet through which heunhap heunhap gas supply comprising a (meth) acrylic acid and organic by-products and water vapor produced by the synthesis reaction of acrylic acid,

And wherein the heunhap gas with a low concentration eu (meth) are acrylic acid aqueous solution is discharged low concentration (meth) obtained by the water contacting acid aqueous solution discharge port is provided to any one of points corresponding to 30 to 70% from the top, high-concentration (meth) acrylic acid the solution outlet is provided in the bottom (meth) acrylic acid absorption tower 100;

A low concentration of (meth) acrylic acid aqueous solution outlet and the solution transfer line 103, the associated solution inlet port, the inlet (meth) acrylic acid aqueous solution and extracted (meth) acrylic acid extract obtained by the contact of the solvent is discharged through the absorber 100 a balance weight provided with a discharge port which is the extract outlet, and the weight balance is discharged (meth) acrylic acid extraction column 200;

The extraction connected via the extract outlet and the extract feed line 203 of the tower 200, and the (meth) (meth) feed (feed) is connected via the acid aqueous solution outlet and the feed line (102) of the acrylic acid absorption tower 100 entering off-premises eu, feed (feed) a water separation column 300 is provided with an outlet at the bottom is discharged, except for distilled water in which the distillate of the inlet feed (feed) the top of the discharge outlet and the inlet feed (feed); And

The water separation column is acetic acid (300) obtained by the heating of the feed (feed) inlet and a feed inlet (feed) is connected via a bottom outlet and a transfer line 303 of the outlet port and .. ((methoxy acrylic acid which is discharged meth) contains the acetic acid separation column 500 is provided with a discharge port of acrylic acid,

Feed (feed) is the weight ratio of extraction solvent to water in the low-concentration (meth) acrylic acid aqueous solution supplied to the (meth) acrylic acid extraction column 200 is at least 2.7, the inlet to the acid separation column the acetic acid from 0.1 to 10 wt. 0 / 0 acrylate, 60 to 99% by weight, and is operated to include the residue of organic by-products,

(Meth) may be provided continuous system for recovering acrylic acid.

That is, in the one embodiment the apparatus, essentially of (meth) acrylic acid absorption tower 100 is connected to the (meth) acrylic acid extraction column 200 via a low-concentration (meth) acrylic acid aqueous solution feed line 103. Then, the (meth) acrylic acid extraction column 200 has a (meth) being connected to a water separation column 300 through the acrylic acid extract feed line 203, a water separating column 300 feed (feed other than the distillate from the extract ) it is connected to the acetic acid separation column 500 via the transfer line 303 of the.

In particular, the continuous recovery apparatus of the one embodiment the (meth) acrylic acid is the

(Meth) acrylic acid absorption column has a low concentration of (meth) acrylic acid aqueous solution from the top of the discharge port 100 to any of the points corresponding to 30 to 70% is located, there is a high concentration of (meth) acrylic acid aqueous solution outlet located at the lowest end.

In addition, the apparatus is connected via a (meth) acrylic acid aqueous solution outlet and the feed line (102) of being connected via the extract outlet and the extract feed line 203 of the extraction tower 200, the (meth) acrylic acid absorption tower 100 feed (feed) inlet port may be located at any one stage corresponding to from 25 to 75% relative to all the uppermost end of the water separating column (300).

In addition, the apparatus is one of a feed (feed) inlet port connected through a bottom outlet and a transfer line 303, the water separation column 300 corresponds to the 40 to 70% of the total stage number from the top compared to the acetic acid separation column 500, It may be located on one.

And (meth) acrylate, the type of the absorption tower 100 is chungjan column types (packed column type) of the absorption tower, a multistage tray type (multistage tray type) may be, lashing inside the absorption tower of the packed column type ring may be a filler of the like is applied (rashing ring), polling (pall ring), saddle (saddle), gauze (gauze), structured packing (structured packing).

And, a (meth) acrylic acid extraction column 200 includes a liquid - can be used without a conventional extraction column of the liquid contact method limited. Non-limiting examples, the extraction tower 200 Karr type of the reciprocating plate column (Karr type reciprocating plate column), rotating-disk-shaped column (rotary-disk contactor), Scheibel columns and Kuhni columns, spray state jultap (spmy extraction tower), mogul main jultap (packed extraction tower), Phelps packed column (pulsed packed column) and the like.

Then, the water separation column 300, and the acetic acid separation column 500, is a pack containing the aforementioned fillers inside the column or multi-stage column, preferably a sieve tray column (sieve tray column), a dual flow tray column (dual flow tray column) may be provided with the.

In addition, the acetic acid absorption tower 150, a (meth) acrylic acid aqueous solution transfer line 103, extracts the transfer line 203, a phase separation vessel 350, the high boiling point by-product separation column (400) shown in Figure 1 and the like may be one having a conventional configuration in the art.

【Effects of the Invention】

A continuous method for recovering (meth) acrylic acid according to the invention is yet to ensure a high (meth) acrylic acid recovery through separation, enables the stable (meth) acrylic acid recovery and operation of a continuous process.

[Brief Description of the Drawings

Figure 1 shows a continuous recovery method and apparatus of the (meth) acrylic acid in accordance with one embodiment of the present invention. '

- specific information for carrying out the invention;

To the practice of the invention will be described in more detail in the examples. However, the following examples are not limited by the exemplary ExamplesExamples of this disclosure, it may make the present invention to the ordinary for this invention.

Example

Also using the construction of the apparatus, such as 1, it was carried out the following acrylic acid recovery process, such as continuous.

(Extraction step)

To the side of the absorber 100 is discharged (103) acrylic acid aqueous solution of a low concentration (the composition of acrylic acid 21.06 weight 0 / 0 , acetic acid 4.15 increase 0 / 0 , and water 74.79 parts by weight 0 / 0 extract the acid in) a solvent feed line (302 It was extracted in accordance with the liquid contact method -) to the liquid injected by using toluene. To the top of the extraction column 200 extract 203 is withdrawn, the weight balance can be re-circulated to the top portion of the acrylic acid absorption 100 via the discharge into the lower portion of extraction column weight balance transfer line 201 there eu

Acrylic acid extraction column 200 in the reciprocating plate Karr column of the type of gun 56 with an internal diameter of 22mm (Karr reciprocating plate column type) was used. Acid aqueous solution 103 at a low concentration to be discharged to the side of the acrylic acid absorption column 100 was introduced to 23.8 g / min over the first end of the top of the extraction column (200). Then, the extraction solvent (the composition of the water separation column (300) a part of the reflux stream extraction column 200, containing toluene to give the organic layer from the top discharge liquid: acrylic acid of about 0.27% by weight of acetic acid of about 0.48 weight 0 / 0 , was used in the remaining toluene), and the extraction solvent was introduced at a rate of 59.44 g / min through a second 56 bottom of the extraction column (200).

As after the stable operation is performed the upper portion of the extraction column 200 in the normal state 64.59 g / flow rate of acrylic acid extract of min (composition: a toluene about 91.32 weight 0 / 0 acrylate, from about 7.42 wt. 0 / 0 , the water from about 0.62 wt. 0 / and acetic acid about 0.64 wt) is obtained was, and the remaining weight balance to the lower portion of extraction column 200 (composition: water of about 93.36 weight 0 / 0 acrylate, from about 2.03 wt. 0 / 0 , and nitric acid of about 4.61 weight 0 / 0 ) was leaked.

Operating results of the acid extraction column 200, the water removal rate for the low-concentration acrylic acid solution discharged from the side of the acrylic acid absorption tower was 97.8%, the extraction rate of acrylic acid was 92.7%. At this time, the extraction solvent / water ratio injected into the extraction column was 33.

(Distillation step)

A water separating column with inner diameter of 70mm for a total of 39 (300) Sieve tray (including down keomeo) was used as the column, the operating pressure was maintained at 110 torr. Lower discharge liquid of the upper extract (203) and the acrylic acid absorption tower 100 of the extraction column 200 of a extraction step (102) each from the top of the all-water separation column 300, the position of the 20 55.06 g / min, It was introduced at a rate of 34.41 g / min. And was introduced into a separate phase from the separation vessel 350 at a rate of 25.96 g / min at the top of the first stage of water separation column 300, a part of the toluene reflux stream as an azeotropic solvent.

Further, the silver is in the 35 "water separation column 300 to provide heat through reboiler (reboiler) of the lower end of the water separating column (300) 50 ° was adjusted to not more than C. After a stable operation for about 6 hours to perform, it was a 31.80 g / organic phase and 10.45g / mm of water in the distillate min to the top of the water separation tower 300, flowing out of the steady state, the water separation column (300) the acrylic acid stream of 47.22g / min was obtained as a bottom. At this time, the temperature of the top of the water separation column 300 in the normal state is 39.2 ° C, and the temperature of the bottom is 88.2 ° were maintained respectively C. The organic phase distillate (304) is acrylic acid and 0.07 parts by weight 0 /., Acetate 0.02 0 / 0 , the showed a composition of influenza 99.91 weight, water minutes ratap bottoms stream 303 is acrylic acid 92.53 weight 0 / 0 , acetic acid 2.53 weight 0 / 0 showed a composition of 4.94% by weight of toluene. Acrylic acid recovery in the water separation column 300 was 99.7%.

(Acetic acid separation step)

Was acetate using Dualflow tray column of the separation column 300, the inner diameter of 20 mm for a total of 15, the operating pressure was maintained at 80 torr eu separating the bottoms stream 303 of water separating column 300 of the distillation process acetate from the top of the tower 500 to the position of the 9 it was introduced to 5.1 g / min. Then, the acetic acid separation column 500, the first end top of the acetic acid separation column 500 as reflux a portion of the overhead stream was introduced at a rate of 5.2 g / min. .

In addition, the distilled water feed to the column through a reboiler (reboiler) in the bottom of the acetic acid separation column 500, 10, based on the weight of the feed amount 0 / 0 was adjusted so that the. After the stable operation for about 5 hours is performed, a normal state sseseo acetic acid separating column (500) above to 0.51 g / min in distilled water was leaked, acrylic acid stream of 4.59 g / min to the bottom of the acetic acid separation column 500, this was obtained. At this time, the silver is 53 in the upper portion of the acetic acid separation column 500, in the steady state ° C, and the temperature of the bottom is 85 ° was maintained in each C. Acetic acid separation tower overhead stream 501 is at steady state is acrylic acid 23.62 weight 0 / 0 , acetic acid 24.38 weight 0 / 0 , the toluene 52.00 weight 0 / 0 and acetic acid separation tower bottoms stream 502 is acrylic acid 97.72 weight 0 / 0 , 1100 ppm of acetic acid, high boiling point substance and a polymerization inhibitor 2.28 parts by weight 0 / 0 shows the composition of the. The recovery of acetic acid separation column 500 was 97.4%.

Comparative Example

With the exception that with the exception of acetic acid and separation process in the embodiment, and the distillation process proceeds as described below was carried out continuously acrylic acid recovery process in the same way.

■

(Distillation step)

A water separating column with inner diameter of 70mm for a total of 39 (300) Sieve tray (including down keomeo) was used as the column, the operating pressure was maintained at 110 torr. In the 20 position from the top of the acrylic acid absorber bottoms discharge of 100 liquid 102 as in Example 1, extraction tower 200, the water separation column 300, an upper extract (203) of each of 44.99 g / min It was introduced into 36.4 g / min. And was introduced into a separate phase from the separation vessel 350 at a rate of 22.22 g / min at the top of the first stage of water separation column 300, a part of the toluene reflux stream as an azeotropic solvent. At this time, the upper extract (203) the weight ratio of toluene in the extraction of the injected liquid reflux introduced into the separated water within the tower overhead into toluene and water separation column feed input stage tower is 0.66: 1.

Further, by supplying heat via reboiler (reboiler) of the base of the water separation column 300 has silver is the feed input end of the water separating column (300) 64.6 ° C, the temperature of the fifteenth stage of about 46 ° is C was controlled so as not to exceed .. after the stable operation for about 6 hours to perform, water separation tip in a steady state " was a 33.86 g / min of the organic phase and a water distillation of 8.50 g / min of water to the top of the (300) outlet, the lower acrylic acid stream of 39.03 g / min to the water separation column 300 was obtained. at this time, the upper temperature of the water separation column 300 in the normal state is 42.4 ° C, and is lower in silver is 92,31. each holding was. the organic phase distillate (3C4) is acrylic acid 0.73 parts by weight 0 / 0 , acetic acid 0.76 weight 0 / 0 , the roll toluene 98.51 weight 0 / 0 showed the composition of the water separation tower bottoms stream 300 is acrylic acid 9815 parts by weight 0 / 0 , 3000 ppm acetic acid, acrylic acid oligomer and a polymerization inhibitor increased 1.85 0 / 0 showed the composition of the water separation column (30 The recovery of acrylic acid 0) was 98.7%.

[Description of Symbols]

1: a (meth) acrylic acid-containing gas heunhap

100: (meth) acrylic acid absorption tower

102: high-concentration (meth) acrylic acid aqueous solution feed line

103: low-concentration (meth) acrylic acid aqueous solution feed line

150: acetic acid absorption tower

200: a (meth) acrylic acid extraction column

201: Autumn balance transfer line

203: extract feed line

300: Removing the top

301: azeotropic solvent feed line

302: extraction solvent feed line

303: Removing bottoms stream

304: Removing overhead stream

305: absorbing the solvent (water) transfer line

350: a separation vessel

400: The high-boiling byproducts minutes ratap

500: acetic acid separation column

501: acetic acid separation tower overhead stream

502: (meth) acrylic acid feed la

WE CLAIM

[Claim 1]
(Meth) which is brought into contact with mixed gas containing the (meth) acrylic acid and organic by-products and water vapor generated by the synthesis banung of acrylic acid (meth) with water in the acrylic acid absorption column corresponding to 30 to 70% from the top of the absorption tower and low-concentration (meth) acrylic acid solution discharged from a point, to obtain a high concentration of (meth) acrylic acid solution discharged to the bottom of the absorption tower;

Is contacted with a low concentration commerce meth) extraction solvent comprising a hydrophobic organic solvent in the acrylic acid aqueous solution of (meth) acrylic acid extraction column (meth) extracting acrylic acid;

Step of distilling the obtained (meth) acrylic acid extract, and high-concentration (meth) arc ¾ acid aqueous solution of the water separation column to obtain a distillate; And

The (meth) acrylic acid extract, and high-concentration (meth) by a feed (feed), except for distilled water in the acrylic acid aqueous solution heated in acetic acid separating column (meth) acrylic acid to obtain a; includes;

The (meth) arc ralsan step a low concentration of (meth) (meth) acrylic acid extract, and high-concentration (meth) flowing in a weight ratio of extraction solvent to the water in the acid receiving amplifier is more than 2.7, the acetic acid separation column feed in to extract the feed (feed), except for distilled water in the acrylic acid aqueous solution is 0.1 to 10 parts by weight of acetic acid 0 / 0 acrylate, 60 to 99 parts by weight 0 / 0 methods continuous recovery of (meth) acrylic acid containing the organic by-products and residual.

[Claim 2]

According to claim 1,

The low concentration of (meth) acrylic acid aqueous solution of (meth) acrylate, 1 to 50 parts by weight 0 / 0 , water from 50 to 95 weight 0 / 0 methods continuous recovery of that containing the organic by-products of the and the remaining amount which is characterized, (meth) acrylic acid.

[Claim 3]

According to claim 1,

The extraction solvent is benzene (benzene), a toluene (toluene), and xylene (xylene), n- heptane (n-heptane), cycloheptane (cydoheptane), cycloheptene (cycloheptene), 1- heptene (1-heptene) , ethyl-benzene (ethyl-benzene), methyl-cyclopentane nucleic acid (methyl-cyclohexane), n- butyl acetate (n-butyl acetate), isobutyl acetate (isobutyl acetate), isobutyl acrylate (isobutyl acrylate), n- propyl acetate (n-propyl acetate), isopropyl acetate (isopropyl acetate), methyl isobutyl ketone (methyl isobutyl ketone), 2- methyl-1-heptene (2-methyI-l-heptene), 6- methyl-1 heptene (6-methyl-1-heptene), 4- methyl-1-heptene (4-methyl-l-heptene), 2- ethyl-1-haeksen (2-ethyl-l-hexene), ethyl cyclopentane (ethylcyclopentane ), 2-methyl-1-haeksen (2-methyl-l-hexene), 2,3- dimethyl cyclopentane (2,3-dimethylpentane), 5- methyl-1-haeksen (5-methyl-l-hexene), and selected from the group consisting of ether (isopropyl-butyl-ether) - isopropyl-butyl Where: At least one containing a hydrophobic organic solvent, (meth) continuous method for recovering acrylic acid eu

[Claim 4]

According to claim 1,

The (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid aqueous solution is water separated: one corresponding to 25 to λ 75% full can from the top end against the top. Characterized in that the geotol supplied to the one (meth) continuous method for recovering acrylic acid.

[5.]

The method of claim wherein Γ,

The water separation column is the top of the pressure from atmospheric pressure to 20 torr, the operating temperature of the bottom, characterized in that 40 to 100 ° C, (meth) continuous method for recovering acrylic acid.

[6.]

According to claim 1,

The (meth) acrylic acid extract, and a high concentration of (meth) acrylic acid " feed (feed), except for distilled water in the aqueous solution from the top end of the total of acetic acid separating column prepared

To be supplied to any one corresponding to 40 to 70%, it characterized in, the (meth) acrylic acid in a continuous recovery method.

[Claim 7]

According to claim 1,

The acid separating column had a pressure of from atmospheric pressure to 20 torr top, and the top temperature 40 to 90 ° C, a lower temperature, characterized in that 50 to 100 ° C, (meth) continuous method for recovering acrylic acid.

[8.]

According to claim 1,

In the acetic acid separating column (meth) acrylic acid extract, and a high concentration

(Meth) heating the feed (feed), except for distilled water in the acrylic acid aqueous solution characterized in that the top discharge liquid obtained from the top are input to the (meth) acrylic acid extraction column, (meth) continuous method for recovering acrylic acid.

[9.]

(Meth) (meth) produced by the synthesis banung of acrylic acid and organic by-products and water vapor heunhap low concentration (meth) being provided with a mixture gas inlet through which gas is supplied, and obtained by the above heunhap gas and water contact, including an acrylic acid low concentration (meth) and the acrylic acid aqueous solution discharge port is provided to any one of points corresponding to 30 to 70% from the top, high-concentration (meth) (meth) acrylic acid absorption tower having an acid aqueous solution discharge port at the bottom which the aqueous solution is discharged (100) .;

A low concentration of (meth) acrylic acid aqueous solution outlet and the solution transfer line 103, the associated solution inlet port, the inlet (meth) acrylic acid aqueous solution and extracted (meth) acrylic acid extract obtained by the contact of the solvent is discharged through the absorber 100 a balance weight provided with a discharge port which is the extract outlet, and the weight balance is discharged (meth) acrylic acid extraction column 200;

The extraction connected via the extract outlet and the extract feed line 203 of the tower 200, and the (meth) (meth) feed (feed) is connected via the acid aqueous solution outlet and the feed line (102) of the acrylic acid absorption tower 100 inlet, a feed (feed) a water separation column 300 is provided at the bottom outlet is discharged other than the distillate from the top distillate is the discharge of the inlet feed (feed) inlet and outlet feed (feed); And

Connected through a bottom outlet and a transfer line 303 of the water separation column 300, the feed (feed) inlet and, obtained by the heating of the incoming feed (feed), acetic acid outlet and a (meth) (meth that acrylic acid is discharged ) includes the acid separating column (500) having an acid outlet,

The (meth) increased ratio of 2.7 or more of the extraction solvent to water in the low-concentration (meth) acrylic acid aqueous solution fed to the acid extraction column 200 is a high-i, the feed (feed) introduced to the acetic acid separation column is acetic acid 0.1 to 10 parts by weight 0 / 0 acrylate, 60 to 99 parts by weight 0 / 0 continuous recovery device eu of the (meth) acrylate is operated to include organic by-products and residual

[10.]

10. The method of claim 9,

The extraction column are connected via the extract outlet and the extract feed line 203 (200), connected via a (meth) arc. Rilsan solution outlet and the feed line 102 of the (meth) acrylic acid absorption tower 100 feed ( feed) inlet is a continuous system for recovering, characterized in that positioned at one end corresponding to 25 to 75% from the top relative to all ends of the water separation tower 300, a (meth) acrylic acid.

[11.]

10. The method of claim 9,

Feed (feed) inlet port connected through a bottom outlet and a transfer line 303 of the water separation column 300 is positioned at any one stage corresponding to from 40 to 70% from the top relative to all stages of the acid separating column (500) a continuous system for recovering the acrylic acid, (meth) characterized in that.