This application claims the benefit of priority based on the 25th Korea Patent Application No. 10-2016-0158615 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.

- that the technical background of the invention;

(Meth) acrylic acid is typically propane, propylene, (meth) gas phase process the di prepared in which banung oxidizing compounds, such as acrolein in the presence of a catalyst -: For example, such anti-propane, in the presence of a suitable catalyst in the unggi propylene by gas-phase oxidation reaction (meth) through an arc the lane (meth) was converted to acrylic acid, in the rear half unggi (meth) acrylic acid, unreacted Pro Fin · : or propylene, (meth) acrolein, inert gases, carbon dioxide, water vapor and the heunhap gas containing various organic by-products (acetate, low boiling point by-products and high boiling point by-products, etc.) by the banung obtained.

The (meth) acrylic acid-containing gas mixture is in contact with the absorption solution in 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. Some of the increase (meth) obtained in the (meth) acrylic acid absorption column and the acrylic acid aqueous solution fed to the extraction column. Getting the use of a hydrophobic solvent, the water content decreases (meth) acrylic acid extract, and the weight balance, the method of distillation with the extract and the remaining solution not fed to the extraction column of the (meth) acrylic acid aqueous solution obtained in the absorption tower It is known.

Further, by selectively released into the (meth) aqueous solution of acrylic acid containing a low concentration in the absorber stop obtain a high concentration of (meth) acrylic acid aqueous solution in the lower portion the absorption tower, a low concentration of (meth) acrylic acid solution emanating from the absorber stop is the extraction column supply and use a hydrophobic solvent, to obtain a the water content decreases (meth) acrylic acid extract, and the weight balance, by supplying the high-concentration (meth) acrylic acid aqueous solution with (meth) acrylic acid extract, the distillation column energy consumption by azeotropic distillation this method is known to reduce eu

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 subsequently water is increased, the amount of the azeotropic solvent to be supplied to the separating column the feed stage, the water separation column top discharge liquid within the (meth) acrylic acid Since the content is lower slaughter water and must be kept constant to a 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 gas / liquid in the water separation column It is the change in behavior occurs. Thus, while drying the water separated ¾ upper tray, thereby reducing the water separating column / bunra efficiency, (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.

- a means of solving problems;

The present invention, (meth) 30 to 70% into contact with a mixed gas (meth) with water in the acrylic acid absorption tower from the top of the absorption tower comprising a (meth) acrylic acid and organic by-products and water vapor produced by the synthesis reaction of acrylic acid 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;

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;

Recovering the solvent by heating the obtained (meth) acrylic acid in the extract solvent recovery column; And

The (meth) distilling the feed (feed), and a high concentration of (meth) acrylic acid aqueous solution other than the solvent recovered from the acrylic acid separation column the extract from water comprising the step of obtaining a (meth) acrylic acid, and;

The (meth) extraction of the water in the feed to the step of extracting a low-concentration acrylic acid (meth) acrylic acid aqueous solution. The weight ratio of the solvent to provide a 2.7 or more, (meth) continuous method for recovering acrylic acid.

In addition, the present invention is produced by the synthesis reaction of (meth) acrylic acid

(Meth) acrylic acid, the gas inlet is heunhap heunhap gases are supplied including the organic by-products and obtain the water vapor provided to the heunhap gas and by the contact of water. Obtained a low concentration of (meth) acrylic acid:... The aqueous solution is discharged is i low concentration (meth) and is provided to any one of points corresponding to 30 to 70% acrylic acid aqueous solution from the exhaust ball top, high-concentration (meth) (meth) acrylic acid absorption tower 100 provided at the bottom the acrylic acid aqueous solution outlet;

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

And extract the inlet is connected via the extract outlet and the extract feed line 203 of the extraction column 200, the feed (feed) than the solvent recovered from the top outlet port and extract the solvent is discharged which is obtained by the heating of the inlet extract a solvent separation column provided with a bottom outlet is discharged (250); And

The solvent is coupled through a bottom outlet and a transfer line 253 of the separation column 250, a (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 and containing a (meth) acrylic acid is (meth) acrylic acid having discharged outlet water separation column 300, which is obtained by distillation of a feed inlet (feed),

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 provides a continuous system for recovering that operation is at least 2.7 (meth) acrylate.

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: eu

Sseseo used herein, referred to as "(meth) acrylic acid, can be used as the acrylic acid (acrylic acid), methacrylic acid (methaaylic acid) or meaning that collectively mixtures thereof.

In this specification, "(meth) acrylic acid-containing gas heunhap 1 means any breakdown in the gas phase oxidation. (Meth) which may be produced when producing the acrylic acid ■ to collectively refer to the gas mixture. That is, according to one embodiment of the invention, at least yisangwa compound ( "compound material") selected from the group consisting of propane, propylene, butane, butylene i-, t- butylene, and (meth) arc in lane a to obtain the (meth) acrylic acid-containing gas mixture by a method of vapor phase oxidation banung presence of a catalyst. In this case, the (meth) acrylic acid-containing heunhap gas, (meth) acrylic acid, US banung starting materials, (meth) arc the lane, block active gas, carbon monoxide, carbon dioxide, water vapor and various organic by-products (acetate, low boiling point by-products and high boiling point It may include such by-products, etc.). Here, "low boiling point by-products" as a kind of (light ends) or "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, referred to "feed" (feed) also is not having a solute and availability with, soluble in the extraction solvent (extraction solvent) as to the mean liquid common compound containing a solute (solute) to be extracted and other ingredients It may be water heunhap of (inert material). Here, the transmitter Applying the extraction solvent to the Pas

Wherein the solute is dissolved in the extraction solvent from the feed by development. 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 (mffinate).

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

Further, the 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.

Hereinafter, the present invention allows for the self having ordinary skill in the art readily will now be described in detail the implementation examples of the present invention with reference to the accompanying drawings. However, the invention is multiple. It ateumyeo be embodied in different forms not only of a ¾ implementation described here, for example.

I. (meth) continuous method for recovering acrylic acid

According to one embodiment of the invention,

(Meth) which is brought into contact with water in the produced by the synthesis reaction of acrylic acid (meth) acrylic acid, the heunhap gas containing the organic by-products and the vapor of (meth) 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 an extraction solvent comprising a hydrophobic organic solvent in the low concentration (meth) acrylic acid aqueous solution of (meth) acrylic acid extraction column (meth) extracting acrylic acid;

Recovering the solvent by heating the obtained (meth) acrylic acid in the extract solvent recovery column; And

The (meth) distilling the feed (feed), and a high concentration of (meth) acrylic acid aqueous solution other than the solvent recovered from the acrylic acid separation column the extract from water comprising the step of obtaining a (meth) acrylic acid, and;

The weight ratio of 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 is 2.7 or more,

(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) when a method of Paulina of acrylic acid increases the amount of the hydrophobic solvent in order to increase the extraction rate and to the solvent amount reduced is introduced into the reflux of the water separation column, the upper part of the stage which the feed and extract the water separation column input accordingly in a tray in an area it becomes a liquid / gas ratio is low. Thus liquid level (liquid level), flood the tray present in the upper area of the stage at which the water separated tapwa kkoedeu and the extract was added 0 / 0 (flood%), Prosper height (froth height) deungeo existing water with an appropriate reflux solvent since separating column driving time it is becomes extremely lower than the & separating column the liquid / gas flow behavior of the upper tray unstable, it was confirmed that a number of problems such that the (meth) acrylic acid recovery in the water separation column decreases occurs.

Thus, continued research by the inventors result, Figs. 1 and when to introduce the solvent recovery process between the (meth) extraction step and the distillation process of acrylic acid, such as 2, (meth) to remove the very low solvent concentration of the acid solvent can be recovered from the tower, and reflux it to the top of the water separation column, so as to increase the reflux ratio of the water separation column, or can be reused in the extraction column and a water separation column to input article phase separation present in the water separation column top, it was confirmed that a more economical and reliable operation of the continuous process is possible.

Note In the following, Figures 1 and 2, description will now be given of each step that can be included in embodiments of the invention.

Absorption process

In the first, the continuous method for recovering the one (meth) acrylic acid in accordance with an embodiment,

(Meth) produced by the synthesis reaction of acrylic acid (meth) acrylic acid, by contacting the heunhap gas containing the organic by-products and water vapor (meth) with water in the acrylic acid absorption tower containing the step of obtaining a (meth) acrylic acid aqueous solution, herein absorption process means a process for obtaining this (meth) acrylic acid aqueous solution.

More specifically, performed as a method of synthesis reaction of the (meth) acrylic acid oxidation banung 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 banung the gas phase oxidation reactor, and the conventional structure: can be carried out under banung conditions eu may be used that the catalyst is also typically in the vapor phase oxidation reaction, for example, Republic of Korea Patent Registration No. 0349602 and No. 037 818 there are disclosed in the catalyst or the like can be used. Produced by the gas phase oxidation banung: "(meth) acrylic acid-containing gas mixture is the desired product. (Meth) may be in addition to acrylic acid, US banung starting compound / intermediate, the (meth) arc the lane, includes a block active gas, carbon dioxide, water vapor, and various organic by-products (acetate, low boiling point by-product high-boiling Busan and the like).

And, FIG. 1, FIG. 2, and the (meth) acrylic acid aqueous solution of (meth) acrylic acid-containing feed to heunhap gas (1) (meth) acrylic acid absorption tower 100, by contact with an absorption solvent water ( meth) can be obtained in the form of an aqueous solution of acrylic acid is 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) the stage tray type (tray multistage type) can be absorber. Absorber of the packed column type lashing ring (rashing ring), inside ■ ring (pall ring), saddle (saddle), it ' may be a filler such as gauze (gauze), structured packing (structured packing) applied .

And, in view of the efficiency of the absorption step, the gas heunhap 1 . Can be supplied to the lower portion of the absorber 100, the absorption solvent containing water can be supplied to the upper portion of the absorption tower 100.

The absorption solvent is deutmul, may comprise water such as deionized yieunsu, may comprise a water circulation step which is introduced from the other process (for example, extraction processes and / or water recycled from the distillation step). Also, the absorption solvents include organic by-products of a very small amount (e. G. Acetic acid) may contain the eu, however, the (meth) acrylic acid to be introduced from the other processes , supplied to the in consideration of the absorption efficiency, the absorber 100 absorbent solvent (in particular the number of the rotation process) is, it is preferable that the organic by-products are contained by more than 15% by weight.

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 8ϋ ° atda be operated under the temperature inside the C.

On the other hand, from the top of the through the absorption step, the (meth) acrylic acid absorption tower 100. 30 which is a to the point corresponding to 70% to the (meth) acrylic acid is increased about 50% or less in a low concentration: the (meth) acrylic acid aqueous solution and discharged, as is the bottom. (Meth) the high concentration of (meth) acrylic acid aqueous solution is at least 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 Figs. 1 and 2, the high-concentration (meth) or supplied to the water separation column 300 through the aqueous acrylic acid solution transfer line 102, a low concentration of (meth) through the aqueous acrylic acid solution transfer line 103, a (meth) acrylic acid can be supplied to the extraction column 200 eu

On the other hand, (meth) acrylic acid at least a portion of biung-condensable gas discharged to the upper portion of the absorber 100 may be supplied to the step for recovering the organic by-products (particularly acetic acid) are included in biung-condensable gases, the remainder of the waste gas incinerator It is supplied to be disposed of. That is, according to one embodiment of the invention, contacting said non-condensable gas and the absorption solvent, a step of recovering the acetic acid contained in the biung-condensable gases can be carried out.

Contacting the biung 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 /., Water 50 to 95 It may include organic by-products in percent by weight and the remaining 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 is a polymerization reaction of (meth) acrylic acid 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 (1 -heptene), ethyl-benzene (ethyl-benzene), methyl-cyclopentane nucleic acid (methyl-cyclohexane), n- butal 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 "bots, i butyl-l - heptene (2-methyl-l- heptene) , 6 -methyl-1-heptene (6-.me: hyl-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 -methy] -l-hexene), 2,3- dimethyl cyclopentane (2,3-dimethylpentane), 5- methyl-1-haeksen ( 5-methyl-l-hexene) , and isopropyl-t-butyl-ether (isopropyl-butyl-eth may include er) the hydrophobic organic solvent is at least one selected from the group consisting of.

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. Thus, it is possible to increase the reflux (reflux), the solvent in the subsequent distillation process that is, as to adjust the amount of the extraction solvent at the extraction step (meth) acrylic acid can further increase the number of hyoeul.

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 extraction efficiency

Undesirably it decreases. Then, the weight ratio of extraction solvent to water in the low-concentration (meth) acrylic acid transfusion 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 the amount of extraction solvent to be distilled in solvent recovery process is not desirable to excessively increase.

In addition, the extraction tower 200 is liquid-may be used without a conventional extraction column of the liquid contact method limited. For example, 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 jujul tower (spray extraction tower), filled extraction tower (packed extraction tower), pulsed packed column (pulsed packed column) and the like.

Through this extraction process, in the upper portion of the extraction column 200 has a (meth) acrylic acid extract is withdrawn, the extract is discharged via the feed line 203 : is fed to a solvent recovery tower 250. In addition, the lower portion of a extraction column 200 is the weight balance has been discharged, the discharged weight balance is supplied to the separation vessel 350 via transfer line 201, the Source . : Ridoe . Air is recirculated. .

'How are you, washing-based extract: may include in addition to the desired compound of (meth) acrylic acid, 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, it is possible to lower the energy consumption by reducing the operating pressure of the distillation process. 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,

It may contain a concentration of 15 wt%, or 0.1 to very little (meth) acrylic acid of 5% by weight, the (meth) acrylic acid loss in the absorption step and the extraction step may be minimized.

Solvent recovery step

On the other hand, the continuous method for recovering the one (meth) acrylic acid according to the embodiment, by heating the (meth) acrylic acid extract obtained in the extraction step from the solvent recovery tower include a step of recovering the solvent.

(Meth) the extract discharged through the top outlet of the acrylic acid extraction column 200 is fed to a solvent recovery column 250 through a feed line 203. The Then, by supplying heat via reboiler (reboiler) of the recovery tower bottom, and recovering the extraction solvent through the top outlet and, except for the number of the extraction solvent , to obtain a (meth) acrylic acid extract through the bottom outlet.

Then, the washing-machine one embodiment the solvent recovery column 250 is the lower silver is 100 ° may be less than C. "Lower" in the solvent recovery tower means the at least one point that fall within 10% from the bottom of the solvent recovery column.

Further, it apgoek the top of the solvent recovery column 250 may be atmospheric pressure to 20 torr for effective distillation of the extract.

On the other hand, the solvent recovered in step for recovering the solvent is 99 weight 0 / 0 may include one hydrophobic organic solvent. The More specifically, the number of times . The solvent is a hydrophobic organic solvent in addition to (meth) acrylate, 1 part by weight the content of 0 / 0 , preferably at most 0.5 0 / 0 or less, and more preferably from 0.3 0 / 0 or less.

In addition, the feed (feed), except for the solvent recovery in the above-mentioned (meth) acrylic acid extraction liquid (meth) acrylate, 5 to 70 parts by weight 0 / 0 may include a hydrophobic organic by-products of the organic solvent 30 to 95% by weight and the remaining amount.

" Further, some of the solvent recovered in step for recovering the solvent is refluxed in a solvent recovery column, and the remaining portion may be recycled is supplied to the top twos or phase separation of the water separation column.

Thus one embodiment the (meth) continuous method for recovering acrylic acid from the solvent recovery process. The extraction solvent is recovered and the solvent recovery process, the extracted amount by the water it is possible to increase the amount of the azeotropic solvent to be added to the reflux of the separating column a liquid water separation column feed input end top tray / gas flow behavior of the solvent recovered in is stabilized can be (meth) recovery efficiency of acrylic acid.

Distillation

Then, the continuous method for recovering the one (meth) according to an embodiment of acrylic acid by distillation of the feed (feed), and a high concentration of (meth) acrylic acid aqueous solution other than the solvent recovered from the (meth) acrylic acid extract from the water separation column (meth) and a step for obtaining acrylic acid.

According to one embodiment of the invention, the feed to extract the above-mentioned (meth) the solvent recovered in the solvent recovery process in the acrylic acid extract which is supplied from the process. : By excluding, as the feed, 1 and 2, a solvent recovering from the container (250) is supplied to the water separation column 300 through the feed line 253.

In addition, the high concentrations of (meth) acrylic acid aqueous solution of (meth) ahkeurilsanwa the (meth) acrylic acid produced by the synthesis reaction, the organic portion: product. And containing water vapor: heunhap gas roll (meth) acrylic ¾} brought into contact with water in an absorption tower to be discharged to the bottom of the absorber, as shown in Figs. 1 and 2, the (meth) acrylic acid absorption tower 100 coming ≤ from. conveyed through the line 102 is fed to the water separation column (300).

At this time, in order to enable an efficient distillation can be made, the feed and a high-concentration (meth) acrylic acid aqueous solution is corresponding to one from the top of the total number of stages of the water separating column against which corresponding to 25 to 75% only, or from 25 to 50% be supplied in either one is preferred.

The feed and the high-concentration (meth) acrylic acid aqueous solution to be supplied to a point in excess of 75% from the top of the water separation tower 300, the water can be recovered in the feed, and an aqueous solution of water separating column top discharge liquid contained in, and part of the extraction solvent is not preferable to contain tapwa lower discharge liquid separated water. Further, if the supply to a point of less than 25% from the top of the water separation column, the concentration of acrylic acid in the acrylic acid recovery increases in the water separation column included in the water separation column top liquid is discharged can be reduced.

Then, the feed water supplied to the separating column (300), into contact with an azeotropic solvent is introduced into the top, while heating to the proper temperature is achieved distilled by evaporation and condensation.

At this time, in order to separate the (meth) acrylic acid contained in the feed as a hyoeul enemy from that of the remaining ingredients (e.g., water, acetic acid, solvent extraction and the like), the distillation is preferably carried out by azeotropic distillation.

Solvents for use in the azeotropic distillation is preferably a hydrophobic solvent which does not form an azeotropic and azeotrope and can lead the water and acetic acid and the azeotropic, (meth) acrylic acid. Also, the azeotropic solvent is hydrophobic (meth) lower boiling point than acrylic acid (for example, 120 ° C or less, or 10 to 120 V, or 50 to 120 ° preferably has a boiling point of C).

Specifically, the hydrophobic azeotropic solvents benzene (benzene), a toluene (toluene); Xylene (xylene), hemtan n- (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 (isopi ' opyl acetate), methyl ; Ketone (methyl isobutyl ketone), 2- methyl-1-heptene (2-methyl-l-heptent ), 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 _ haeksen-methyl-1 ( 2 _ methyl-1-hexene) , 2,3-dimethyl cyclopentane (2,3-dimethylpentane), 5- methyl-1-haeksen (5-methyl-l-hexene ) and isopropyl t-butyl-ether selected from the group consisting of (isopropyl-butyl-ether) which can be every day for more than one species.

And, in view of the production efficiency of a circle according to the continuous process, the hydrophobic azeotropic solvent is preferably the same as the extraction solvent in the extraction process. 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, the relatively light liquid (e.g. organic phase) is on the upper portion of the separation vessel 350, the relatively heavy liquid (e. g., water) may be returned to the lower portion of the separating tank (350).

In one embodiment, the solvent in the weight balance, and a solvent recovery column 250, some of the separation vessel 350 of the solvent recovery in the discharge in the extraction tower 200 a and the upper discharge amount of the water separation column 300, the above-described It can be separated into an organic phase containing water, including award. Here, the separated organic phase is fed to the upper end of the water separating column 300 azeotropic : can be used as yongme. And, if desired, at least a portion of the organic phase : is fed to extraction column 200 may be used rosseodo extraction solvent. And, at least a portion of the separated awards in the separation tank 350 is supplied to the (meth) acrylic acid absorption tower 100 may be used as the absorbing solvent, as some of the waste water. It may be processed and the award there may be some acid is included, the award , the concentration of acetic acid contained may vary depending upon the type of the azeotropic solvent and the reflux ratio.

On the other hand, while passing through the above-mentioned (meth) acrylic acid aqueous solution of (meth) acrylic acid absorption tower 100, the extraction tower 200, the solvent recovery tower 250 and the water separation column 300, such as, (meth contained in the aqueous solution ) and at least a portion of the acrylic acid may form a dimer or a Merced hitting. To this (meth) minimize the polymerization of acrylic acid, a conventional polymerization inhibitor, the water separation column 300 may be added.

And, it may contain in addition to a lower portion of the discharge liquid water separating column (300) (meth) acrylate, (meth) acrylic acid polymers of high boiling point by-products such as, the polymerization inhibitor and the like. Thus, if desired, it can be carried out by adding the step of supplying a lower discharge amount of the water separation column 300, the high boiling point by-product separation column (400) separating the high boiling point by-products contained in the lower discharge liquid. Then, the number of times over the course crude (meth) acrylic acid (CAA) can be obtained by (meth) acrylic acid (HPAA) of higher purity through an additional crystallization step. At this time, the high boiling point by-products, so separation step and the crystallization step and the like can be performed by the conventional conditions and clerical script, and the process conditions are not specifically limited.

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. f meth) continuous system for recovering acrylic acid

According to another embodiment of the invention,

(Meth) acrylic acid produced by the synthesis banung of (meth) acrylic Shin: ,, a low concentration and which is provided, obtained by the mixed gas and water, contacting the gas heunhap hydraulic obtain that the gas mixture is supplied containing the organic by-products and water vapor (meth) acrylic acid aqueous solution is a low concentration emissions (meth) acrylic acid aqueous solution of the outlet is equal to 30 to 70% from the top: there is provided on any one point, high-concentration (meth) acrylic acid aqueous solution outlet is a (meth) acrylic acid having at the bottom absorber 100; . ' Ί

The absorber 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) by the contact of the acid aqueous solution and the extraction solvent through the " (meth) that benefit acid extract the discharged extract outlet, and an outlet in which the weight balance weight balance is discharged Guba (meth) acrylic acid extraction column 200;

And extract the inlet is connected via the extract outlet and the extract feed line 203 of the extraction container (200>, the feed (feed) than the solvent recovered from the top outlet port and extract the solvent is discharged which is obtained by the heating of the inlet extract a solvent separation column provided with a bottom outlet is discharged (250); and

The solvent is coupled through a bottom outlet and a transfer line 253 of the separation column 250, a (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 and containing a (meth) acrylic acid is (meth) acrylic acid having discharged outlet water separation column 300, which is obtained by distillation of a feed inlet (feed),

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 driven is at least 2.7,

(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. And, (meth) except for acrylic acid extraction column 200 has a (meth) being connected to the solvent recovery column 250 through an acrylic acid extract feed line 203, solvent recovery column 250 is the solvent recovery in the extract feed ( through the transfer line 253 of the feed) is connected to the water separation column (300).

In particular ,, the continuous recovery apparatus of the one embodiment the (meth) acrylic acid is within the above-mentioned (meth) acrylic acid absorption tower 100, a low concentration of (meth) acrylic acid aqueous solution discharge port to any one of points corresponding to 30 to 70% from the top of, the lowest i Concentrated

(Meth) acrylic acid aqueous solution outlet position. . Λ '

: Further, the apparatus is connected via a (meth) acrylic acid aqueous solution outlet and the feed line 102 for being connected through the transfer and the lower discharge port of the solvent separation column 250, line 253, (meth) acrylic acid absorption tower 100 feed may (feed) inlet is located at any one stage corresponding to from 25 to 75% from the total number of the top end of the water separating column (300) than, and preferably 25 to 50%.

And (meth) acrylate, the type of the absorption tower 100 packed column type (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 (spray extraction may be a tower), mogul main jultap (packed extraction tower), pulse layered columns (pulsed packed column).

Then, the solvent recovery tower 250 and the water separation column 300 is the pack that contains the above-mentioned filler inside the column or multi-stage column, preferably sieve trays ah column (sieve tray column), a dual flow tray column (dual flow a tray column) may be equipped.

In addition, Figs. 1 and acid absorption tower 150, a (meth) shown in Figure 2, aqueous acrylic acid solution transfer line 103, extracts the transfer line 203, a phase separation vessel 350, the high boiling point by-product separation column 400 and the like may be one having a conventional configuration in the art.

Effect of the invention ί ί

A continuous method for recovering (meth) acrylic acid according to the invention is yet to ensure a high (meth) acrylic acid recovery through all the solvent recovery process, stable (meth) jje enables the recovery and operation of the continuous process of acrylic acid: handi -

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.

Figure 2 shows a continuous recovery method and apparatus of the acrylic acid (meth) according to another 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 embodiment, it may make to the contents of the present invention to illustrate the invention eu

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)

: Of the discharge 103 to the side of the absorber 100 in the low-concentration acrylic acid solution (acrylic acid 21.06 weight%, acetic acid 4.15 weight Composition 0 / 0 , and water 74.79 Increased 0 / 0, the extraction solvent feed line (302) acrylic acid in) It was extracted in accordance with the liquid contact method - the inputted through using the toluene solution. To the top of the extraction column 200 extracts 203 the discharge is, the weight balance is discharged to the lower portion of the extraction column to be circulated again to the top part of the acrylic acid absorption tower 100 through a weight balance transfer line 201 can.

Reciprocating plate extraction column of the acid 200 as the Karr type of gun 56 with an internal diameter of 22mm. A column (Karr type reciprocating plate column) were used : eu sides acid aqueous solution 103 at a low concentration to be discharged to the acrylic acid absorption tower 100 is a 23.8 g / min over the first end of the top of the extraction tower 200 was introduced. Then, the extraction solvent (the composition of the water separation tower 300, a part of the reflux stream extraction column 200, containing the toluene thus obtained as the organic layer in the top discharge liquid: acrylic acid - about 0.27% by weight, chossyo 0.48% by weight, was used in the remaining ^ yen), the extraction solvent through the outermost ^ danin claim 56 of the extraction column 200 was introduced at a rate of 59.44 g / min.

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 / 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. ·

Unjan a result, the water removal rate for the low-concentration acrylic acid solution discharged from the side of the acrylic acid absorption tower for acid extraction column 200 was the 9 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.

(Solvent recovery step)

Was used Dualflow tray column in the solvent recovery column with a total diameter 15 of 20mm (250), the operating pressure was maintained at 100 torr. An upper extract (203) of the extraction column 200 of a extraction step was introduced into a 0.98 g / min at the bottom of the solvent recovery tower 250. Then, the flow was introduced in the reflux liquid 252 of the overhead stream of the solvent recovery tower 250 to the first end top of the solvent recovery tower 250 at a flow rate of 4.41 g / min.

Further, such that the reboiler stream 251 is 50% by mass of the extract compared to injected with solvent recovery tower, except for reflux of the overhead stream of solvent recovery tower to supply heat through (reboiler) in the bottom of the solvent recovery tower 250 It was adjusted. , Which was the steady state leakage in the solvent recovery tower flow (251), except for reflux of the overhead stream is 0.49 g / min of flow rate, the lower the flow 253 of the solvent recovery column, after the stable operation for about 4 hours to perform the 0.49 has been released into the flow g / min. In this case, the solvent temperature of the top of the recovery tower 250 is 49 ° C, and the temperature of the bottom is 62 ° was maintained in each C .. solvent recovery tower overhead stream of reflux other than the flow (251) and the reflux liquid stream ( 252) acrylic acid and 0.32 parts by weight 0 / 0 , acetic acid 0.51 weight 0 / 0 , the toluene , showed a composition of 99.17% by weight, and solvent recovery tower bottoms stream 253 is acrylic acid 19.76 weight 0 / 0 , acetic acid 0.49 weight 0 / 0 shown frame influenza composition of 79.75% by weight. A solvent recovery tower 250 and acrylic acid recovery rate was 98.4%, and. The toluene stripping ratio is . It was 55,6%.

(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. Solvent recovery process of solvent recovery tower 250, the lower portion of the bottoms stream (253) of was introduced at a rate of 17.3g / min for the location of the 17 from the top of the water separation tower 300, the acrylic acid absorption tower 100 discharging the liquid 102 is introduced from the top of the water separation column 300 with a 55.1g / min flow rate on a position of the 19th stage. And, a portion of the solvent recovery column 250, a was introduced at a rate of 22.6 g / min to a phase separation tank 350, the flow 251, except for reflux of the overhead stream separated in phase separation tank 350, toluene reflux flow It was introduced at a rate of 54.3g / min for the first stage the top of the water separation column 300 as an azeotropic solvent. When the mass ratio of the water separation column within the flow 251 within the reflux liquid introduced into the upper part except for the toluene and water separating column the reflux liquid of the solvent recovery tower overhead stream injected into feed input end toluene is 3.7: 1.

In addition, the water separation column 300, a reboiler and through (reboiler) supplying heat, the temperature of the feed input end of the water separating column (300) 68.6 bottom of ° the temperature of a C, feed input end bottom 21 of the 80 ° C or was adjusted so that the. After a stable operation for about 6 hours to perform, was a 37.20 g / organic phase and 11.80g / min and water is distilled water min of water to the top of the separation column 300, flowing out of the steady state, the water separation column (300) the acrylic acid stream of 46.00g / 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 40.9 ° C, and the temperature of the bottom is 94.3 ° were maintained respectively C. The organic phase distillate (304) is acrylic acid, 0.23 parts by weight 0 / 0 , acetic acid 0.48 weight 0 / 0 , the showed a composition of influenza 99.29 parts by weight, the water separation column bottoms stream 303 is acrylic acid 98.58 weight%, acetic acid, 2100 ppm, a high boiling point It showed the composition of the material and the polymerization inhibitor 1.42 increased. Water separation tower 300 and acrylic acid recovery was 99.8%.

Comparative Example

Except for the solvent recovery process in the embodiment, and except that one proceed directly to the distillation step to be described later in the extraction process 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 silver is the 15th stage from about 46 ° is C It was adjusted so as not to exceed. After the stable operation for about 6 hours to perform,

It was steady state is 33.86 g / min the organic phase and 8.50 g / Prime distillate min to the top of the water separation column 300, emanating from, the acrylic acid stream of 39.03 g / min into the lower portion of the water separation column 300 obtained lost. In this case, silver is the top 42.4 of the water separation column 300 at the steady state ° C, and the bottom temperature is 92.3 ° were maintained respectively C. The organic phase distillate (304 ) is acrylic acid 0.73 parts by weight 0 / 0 , acetic acid 0.76 weight 0 / 0 , the showed a composition of toluene 98.51% by weight, the water separation column bottoms stream 300 is acrylic acid 98.15 weight%, acetic acid, 3000 ppm, acrylic acid It showed the composition of the oligomer and increase alloy jije 1.85% by weight. The recovery of acid water separation column 00) 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

250: a solvent recovery tower

251: flow, except for reflux of the solvent recovery tower overhead stream liquid

252: reflux liquid flow of the solvent recovery tower overhead stream

253: a solvent recovery tower bottoms stream

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: high boiling point byproducts separation column

WE CLAIM

[Claim 1]
(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;

Recovering the solvent by heating the obtained (meth) acrylic acid in the extract solvent recovery column; And

The (meth) distilling the feed (feed), and a high concentration of (meth) acrylic acid aqueous solution other than the solvent recovered from the acrylic acid separation column the extract from water comprising the step of obtaining a (meth) and arc ralsan;

The (meth) by weight of the bar of the extraction solvent to water in the feed to the step of extracting a low-concentration acrylic acid (meth) acrylic acid aqueous solution is 2.7 or more, (meth) acrylic acid in a continuous recovery method eu

[Claim 2]

According to claim 1,

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

[Claim 3]

According to claim 1,

The extraction solvent is 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 nucleic acid (methyl-cyclohexane), n- butyl acetate (n-butyl acetate), isobutyl acetate (isobutyl acetate), isobutyl acrylate (isobutyl aery late) 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-1-heptene ), 4- methyl-1-heptene (4-methyl-l-heptene ), 2- ethyl-1-hexene (2-ethyl-l-hexene ), ethyl cyclopentane (ethylcyclopentane ), 2-methyl-1-haeksen (2-methyl-l-hexene), 2 3- dimethyl pentane ( 2 , 3 -dimethylpentane), methyl-1-haeksen ( 5 _methy 1-1 -hexene) and isopropyl - butyl-ether from the group consisting of (isopropyl-butyl-ether) Comprising a hydrophobic organic solvent is at least one selected (meth) acrylic acid in a continuous recovery method.

[Claim 4]

According to claim 1,

The solvent recovery tower bottom temperature is 100 ° or less, and C ,, continuous method for recovering the pressure of the top of the atmospheric pressure to 20 torr which is characterized, (meth) acrylic acid.

[5.]

According to claim 1,

The recovered in recovering the solvent. The solvent is increased to 99% hydrophobic continuous recovery of acrylic acid comprises an organic solvent, (meth) characterized in the method of eccentricity.

[6.]

According to claim 1,

Some of the solvent recovered in step for recovering the solvent and solvent recovery tower as reflux, the other part is a continuous recovery method of characterized in that the input twos top or phase separation of the water separation column, (meth) acrylic acid eu

[7.]

According to claim 1,

The (meth) feed (feed) than the solvent recovered from the acid extraction liquid (meth) acrylate, 5 to 70 parts by weight 0 / 0 , a hydrophobic organic solvent 30 to 95 parts by weight 0 / 0 , and

Characterized in that it comprises a residual amount of organic by-products, (meth) continuous method for recovering acrylic acid.

[8.]

According to claim 1,

The (meth) feed (feed), and a high concentration of (meth) acrylic acid aqueous solution other than the solvent recovered from the acrylic acid extract is characterized in that the supply of any one stage corresponding to from 25 to 75% from the top of the total number of stages of the water separating column prepared , (meth) acrylic acid to a continuous method for recovering.

[9.]

(Meth) the low concentration that is provided with a heunhap gas inlet through which heunhap gas is supplied which contains a (meth) acrylic acid and organic by-products and steam rolls produced by the synthesis reaction of acrylic acid, and obtained by the above heunhap gas and water contact (methoxy eu) the acid aqueous solution is discharged low concentration (meth) acrylic acid aqueous solution discharge port is provided at the one point corresponding to 30 to 70% from the top, and high-concentration (meth) acrylic acid solution discharged is, balls, 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;

And extract the inlet is connected via the extract outlet and the extract feed line 203 of the extraction column 200, the feed (feed) than the solvent recovered from the top outlet port and extract the solvent is discharged which is obtained by the heating of the inlet extract a solvent separation column provided with a bottom outlet is discharged (250); And

The solvent is coupled through a bottom outlet and a transfer line 253 of the separation column 250, a (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 and containing a (meth) acrylic acid is (meth) acrylic acid having discharged outlet water separation column 300, which is obtained by distillation of a feed inlet (feed),

The (meth) acrylic acid extraction column a low concentration (meth) (meth) driven weight ratio of extraction solvent to the water in the acrylic acid aqueous solution is at least Z7 supplied to the 200 continuous recovery of acrylic acid ranging-value.

[Claim 10]

10. The method of claim 9,

The solvent is coupled through a bottom outlet and a transfer line 253 of the separation column 250, a (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 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.