WO2015012551A1 - Method and apparatus for continuously recovering (meth)acrylic acid - Google Patents

Method and apparatus for continuously recovering (meth)acrylic acid Download PDF

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Publication number
WO2015012551A1
WO2015012551A1 PCT/KR2014/006608 KR2014006608W WO2015012551A1 WO 2015012551 A1 WO2015012551 A1 WO 2015012551A1 KR 2014006608 W KR2014006608 W KR 2014006608W WO 2015012551 A1 WO2015012551 A1 WO 2015012551A1
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WO
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Prior art keywords
acrylic acid
meth
extraction
absorption tower
column
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PCT/KR2014/006608
Other languages
French (fr)
Korean (ko)
Inventor
백세원
송종훈
유설희
Original Assignee
주식회사 엘지화학
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Priority claimed from KR1020140091243A external-priority patent/KR101628287B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201480041553.XA priority Critical patent/CN105408296B/en
Priority to BR112016001526-6A priority patent/BR112016001526B1/en
Priority to US14/903,206 priority patent/US9962625B2/en
Publication of WO2015012551A1 publication Critical patent/WO2015012551A1/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
    • C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation

Definitions

  • the present invention relates to a method and apparatus for continuous recovery of (meth) acrylic acid.
  • (Meth) acrylic acid is generally prepared by a method of reacting gas phase oxidation in the presence of a catalyst with compounds such as propane, propylene and (meth) acrolein.
  • propane, propylene and the like are reacted by gas phase oxidation reaction in the presence of a suitable catalyst in the reaction. It is converted into (meth) acrylic acid via (meth) arklane, and (meth) acrylic acid, unreacted propane or propylene, (meth) arklane, inert gas, carbon dioxide, water vapor, and various reactions by the reaction at the rear end of the reactor.
  • a reaction product mixed gas is obtained that includes organic byproducts (acetic acid, low boiling byproducts, high boiling byproducts, and the like).
  • the said (meth) acrylic acid containing mixed gas is contacted with absorption solvents, such as process water, in a (meth) acrylic acid absorption tower, and is collect
  • absorption solvents such as process water
  • a method of azeotropic distillation using a hydrophobic solvent in a distillation column is known as a method for separating water and acetic acid from an aqueous (meth) acrylic acid solution obtained in a (meth) acrylic acid absorption tower.
  • the azeotropic distillation method is a method of effectively recovering (meth) acrylic acid by recovering acetic acid, which is a main by-product of (meth) acrylic acid synthesis reaction, with water through a distillation process using a hydrophobic solvent.
  • the inventors of the present invention through the Republic of Korea Patent Publication No.
  • the azeotropic distillation method and the previously described method of recovering (meth) acrylic acid not only consume a large amount of energy in the process of distilling an aqueous (meth) acrylic acid solution, but also have a high processing burden of the distillation process. Due to the polymer production by the polymerization of meth) acrylic acid there is a problem that the stability of the process operation is inferior, such as normal operation is impossible.
  • the present invention is to provide a method for continuous recovery of (meth) acrylic acid, which can significantly reduce energy consumption and enable stable recovery of (meth) acrylic acid and operation of a continuous process.
  • this invention is providing the apparatus which can be used for the continuous collection
  • the balance obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the (meth) acrylic acid absorption tower,
  • the weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column is more than 0.3 and less than 1.0, the continuous recovery method of (meth) acrylic acid Is provided.
  • the absorption process is performed in a packed column type (meth) acrylic acid absorption tower, and the balance obtained through the extraction process is compared with the total packing height of the (meth) acrylic acid absorption tower. It may be supplied to at least one point corresponding to 10 to 30% from the top.
  • the absorption process is carried out in the (meth) acrylic acid absorption tower of the multistage tray type (multistage tray type), the balance obtained through the extraction process is the total of the (meth) acrylic acid absorption tower It may be supplied to at least one stage corresponding to 10 to 30 0 /.
  • the extraction solvent may be a hydrophobic solvent having a boiling point of 10 to 120 ° C.
  • the extract obtained through the extraction process includes 30 to 60% by weight of (meth) acrylic acid, 30 to 60% by weight of 0 / ⁇ extraction solvent, 3 to 10% by weight 0 / ⁇ water, and the remaining amount of organic by-products can do.
  • the weight balance of a (meth) acrylic acid obtained through the extraction process may comprise less than 15 wt. 0/0.
  • (Meth) acrylic acid absorption tower 100 is provided with an aqueous solution outlet;
  • the distillation is provided with an extract inlet of the extraction column 200 and an extract inlet connected through an extract transfer line 203 and a (meth) acrylic acid outlet through which (meth) acrylic acid obtained by distillation of the extracted extract is discharged.
  • Column 300
  • the extraction liquid outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the absorption tower 100 through the extraction liquid conveying line 201 and
  • a continuous recovery apparatus of (meth) acrylic acid is provided, which is operated so that the weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column 200 is greater than 0.3 and less than 1.0.
  • the (meth) acrylic acid absorption tower 100 is a absorption column of a packed column type, and the extraction liquid outlet of the extraction column 200 is connected to the extraction liquid conveying line 201. It may be connected to at least one point corresponding to 10 to 30% from the top of the total packing height of the absorption tower 100.
  • the (meth) acrylic acid absorption tower 100 is a multistage tray type absorption tower, and the extraction liquid outlet of the extraction column 200 is the extraction liquid transport line 201.
  • the absorption tower 100 may be connected to at least one end corresponding to 10 to 30 ° / ° from the top of the total number of stages.
  • the continuous recovery method of (meth) acrylic acid according to the present invention can significantly reduce the amount of the extraction solvent and the energy consumption of the entire process, and minimize the polymerization reaction of (meth) acrylic acid in the recovery process, thereby making it stable (meth) acrylic acid. It allows for the recovery and operation of continuous processes.
  • FIG. 1 schematically illustrates a method and apparatus for continuously recovering (meth) acrylic acid according to one embodiment of the present invention.
  • Acrylic acid' may be used to mean acrylic acid, methacrylic acid, or a combination thereof.
  • (meth) acrylic acid-containing mixed gas refers to a mixed gas that can be produced when synthesizing (meth) acrylic acid by vapor phase oxidation reaction.
  • the (meth) acrylic acid may be reacted by vapor phase oxidation of at least one compound selected from the group consisting of propane, propylene, butane, isobutylene and (meth) acrolein ('raw compound') in the presence of a catalyst.
  • a mixed gas containing can be obtained.
  • the (meth) acrylic acid-containing mixed gas includes (meth> acrylic acid, unbanung raw material compound, (meth) aclein, activating gas, carbon monoxide, carbon dioxide vapor, and various organic by-products (light acetate and low boiling point by-products (light ends)). , High boiling point by-products (heavies, etc.), etc.
  • the term 'light ends' or 'high boiling point by-products' (heavies) may be generated in the manufacturing and recovery process of the desired (meth) acrylic acid.
  • a by-product a compound having a molecular weight of less than or greater than (meth) acrylic acid may be referred to collectively, and a poorly water-soluble float formed by the organic by-product It is called 'scum'.
  • '(Meth) acrylic acid aqueous solution' is an aqueous solution containing (meth) acrylic acid, and can be obtained by, for example, contacting the (meth) acrylic acid-containing mixed gas with an absorption solvent containing water.
  • 'Feed' means a liquid mixture containing a solute to be extracted, and a solute that is soluble in an extraction solvent and an inert material that is not soluble. It may be a complex of.
  • the solute when the extraction solvent is added to the feed, the solute is dissolved from the feed into the extraction solvent by mass transfer. Accordingly, the extraction solvent in which a significant amount of solute is dissolved forms an extract solution, and the feed that loses a significant amount of solute forms a traffic solution.
  • a relatively light phase is applied to the bottom of the extraction column.
  • the relatively heavy phase is fed to the top of the extraction column.
  • the extraction proceeds by contacting the materials supplied to the extraction column, whereby a light phase and a heavy phase of a new composition are obtained.
  • the light phase of the new composition obtained through the extraction process is obtained through the top outlet of the extraction column, and the heavy phase of the new composition is obtained through the bottom outlet of the extraction column.
  • the heavy phase of the new composition obtained through the extraction process remains at a fixed level at the bottom of the extraction column, before being discharged to the bottom outlet of the extraction column, some of which are directed to the bottom outlet of the extraction column.
  • the section of the extraction column in which the heavy-phase is stationary is referred to as the lower stationary section (or the “political section” of the heavy phase).
  • a relatively heavy phase (meth) acrylic acid aqueous solution is supplied to the top of the extraction column, and a relatively light phase
  • the extraction solvent is fed to the bottom of the extraction column.
  • the extraction proceeds by contacting these, and the extract solution in which a considerable amount of (meth) acrylic acid is dissolved and the extract solution in which a considerable amount of (meth) acrylic acid is lost are obtained. Obtained.
  • the relatively light phase of the extract is obtained through the top outlet of the extraction column and the relatively heavy phase of the extract is obtained through the bottom outlet of the extraction column.
  • the (meth) acrylic acid aqueous solution obtained through the absorption process was contacted with an extraction solvent in an extraction column to obtain a (meth) acrylic acid extract and an extract. Extraction process; And
  • the balance obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the (meth) acrylic acid absorption tower,
  • a method for continuous recovery of (meth) acrylic acid wherein the weight ratio of the extraction solvent to the aqueous (meth) acrylic acid solution supplied to the extraction column is greater than 0.3 and less than 1.0.
  • the absorption step is a step for obtaining an aqueous (meth) acrylic acid solution, and may be performed by contacting a (meth) acrylic acid-containing mixed gas obtained through a synthesis reaction of (meth) acrylic acid with an absorption solvent including water.
  • the synthesis reaction of (meth) acrylic acid may be performed by oxidizing reaction of at least one compound selected from the group consisting of propane, propylene, butane, isobutylene, and (meth) acrelane under a gas phase catalyst.
  • the gas phase oxidation reaction may be performed under a gas phase oxidation reaction and reaction conditions of a conventional structure.
  • Conventional catalysts in the gas phase oxidation reaction may also be used.
  • the catalysts disclosed in Korean Patent Nos. 0349602 and 037818 may be used.
  • the (meth) acrylic acid-containing mixed gas produced by the gas phase oxidation reaction includes, in addition to (meth) acrylic acid as the target product, unreacted raw material compound, intermediate (meth) acrelane, inert gas, carbon dioxide, water vapor, and various organic byproducts. (Acetic acid, low boiling by-products, high boiling by-products, etc.).
  • the (meth) acrylic acid aqueous solution is obtained by supplying a (meth) acrylic acid-containing mixed gas (1) to the (meth) acrylic acid absorption tower 100 and contacting with an absorption solvent containing water. Can lose.
  • the type of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the contact efficiency of the mixed gas 1 and the absorption solvent. As a non-limiting example,
  • the (meth) acrylic acid absorption tower 100 may be an absorption tower of a packed column type and an absorption tower of a multistage tray type.
  • the layered column type absorption tower may include a layering agent such as a rashing ring, a pall ring, a saddle, a gauze, and a structured packing.
  • the mixed gas 1 may be supplied to the lower portion of the absorption tower 100, and the absorption solvent including water may be supplied to the upper portion of the absorption tower 100.
  • the absorption solvent may include water such as scum water, deionized water and the like, and may include circulating process water introduced from another process (eg, an aqueous phase recycled from an extraction process and / or a distillation process).
  • the absorption solvent may contain a trace amount of organic by-products (for example, acetic acid) introduced from another process.
  • the absorption solvent (particularly, the circulating process water) supplied to the absorption tower 100 is preferably such that an organic by-product is included in an amount of 15 increase of 0 / ° or less.
  • the balance obtained in the (meth) acrylic acid extraction column 200 to be described later may be recycled to the (meth) acrylic acid absorption tower 100 and used as an absorption solvent.
  • the balance is supplied to at least one point corresponding to 10 to 30% from the top of the absorption tower (100).
  • the (meth) acrylic acid absorption tower 100 may have an internal pressure of 1 to 1.5 bar or 1 to 1.3 bar, 50 to 100 ° C. or more, in consideration of the water content according to the expansion condition of the (meth) acrylic acid and the saturated steam pressure. It can be operated under an internal temperature of 50 to 80 ° C.
  • the (meth) acrylic acid aqueous solution is discharged to the lower portion of the (meth) acrylic acid absorption tower 100, the (meth) acrylic acid is degassed Non-cumulative gas is emitted. At this time, concentration in the (meth) acrylic acid aqueous solution
  • the obtained (meth) acrylic acid aqueous solution may be supplied to the (meth) acrylic acid extraction column 200 through the aqueous solution transfer line 102 as shown in FIG. 1.
  • the aqueous solution transfer line 102 as shown in FIG. 1.
  • the non-uniform gas discharged to the upper portion of the (meth) acrylic acid absorption tower 100 may be supplied to a process of recovering organic by-products (particularly acetic acid) included in the non-uniform gas, and the rest of the waste gas incinerator. It can be supplied and discarded. That is, according to the exemplary embodiment of the present invention, the process of recovering acetic acid included in the non-uniform gas may be performed by contacting the non-uniform gas with an absorption solvent. The process of contacting the non-condensable gas with the absorption solvent may be performed in the acetic acid absorption tower 150.
  • an absorption solvent (process water) for absorbing acetic acid may be supplied to the upper portion of the acetic acid absorption tower 150, and an aqueous solution containing acetic acid may be discharged to the lower portion of the acetic acid absorption tower 150.
  • the acetic acid-containing aqueous solution may be supplied to the upper portion of the (meth) acrylic acid absorption tower 100 to be used as an absorption solvent.
  • the non-axial gas from which the acetic acid is degassed may be circulated in the synthetic reaction process of (meth) acrylic acid and reused.
  • the acetic acid absorption tower 150 can be operated under an internal pressure of 1 to 1.5 bar or 1 to 1.3 bar, and an internal temperature of 50 to 100 ° C or 50 to 80 ° C. have.
  • specific operating conditions of the acetic acid absorption tower 150 may be in accordance with the contents disclosed in the Republic of Korea Patent Publication No. 2009-0041355.
  • an aqueous (meth) acrylic acid solution is contacted with an extraction solvent in an extraction column.
  • An extraction process is performed to obtain the (meth) acrylic acid extract and the balance thereof.
  • the (meth) acrylic acid aqueous solution may be prepared through the above-described absorption process.
  • the extraction process may be performed in the (meth) acrylic acid extraction column 200.
  • the (meth) acrylic acid aqueous solution supplied to the extraction column 200 is an extract solution in which a considerable amount of (meth) acrylic acid is dissolved in contact with an extraction solvent and a considerable amount of (meth) acrylic acid is lost. Each is discharged.
  • the relatively light phase of the extract is obtained through the upper outlet of the extraction column 200
  • the relatively heavy phase of the extract is obtained through the bottom outlet of the extraction column.
  • the balance liquid is present in a fixed amount in a fixed state in the lower stationary section of the extraction column, some of which is discharged to the lower outlet of the extraction column.
  • aqueous (meth) acrylic acid solution may be removed through a method of contacting the aqueous (meth) acrylic acid solution with the extraction solvent in the extraction column 200 (that is, extraction using less energy than distillation).
  • the treatment burden of the subsequent process which is a distillation process
  • the energy efficiency of the entire process can be improved.
  • the polymerization reaction of (meth) acrylic acid that may occur during distillation can be minimized, thereby improving the recovery efficiency of (meth) acrylic acid.
  • the balance obtained in the extraction process is recycled as an absorption solvent in the above-mentioned absorption process.
  • the balance is 10 to 30% from the top, or 10 to 25% from the top, or 15 to 30% from the top of the (meth) acrylic acid absorption tower 100, or It may be fed to at least one point corresponding to 10 to 20% from the top, or 15 to 25% from the top.
  • the weight ratio (S / F) of the extraction solvent to the aqueous (meth) acrylic acid solution (ie, feed) supplied to the extraction column 200 is greater than 0.3 and less than 1.0, or greater than 0.3 and 0.8 or less, or 0.5 or more and 1.0 Or less than 0.5 or more than 0.8.
  • the balance obtained through the extraction process is determined in the absorption tower (100).
  • the amount of the extraction solvent used and the consumption of process energy can be significantly reduced. That is, through the aforementioned process conditions, the recovery method of the embodiment can minimize the loss of (meth) acrylic acid in the absorption process and the extraction process even with a smaller amount of extraction solvent and energy consumption. It is also possible to increase the flux of the solvent (reflux) in the subsequent distillation process to further increase the recovery efficiency of (meth) acrylic acid.
  • the supply point of the balance of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the portion where the substantial absorption is made according to the type of the absorption tower (100). For example, when the absorption process is performed in a (meth) acrylic acid absorption tower of a packed column type, the balance obtained through the extraction process is compared with the total packing height of the (meth) acrylic acid absorption tower. It may be supplied to at least one point corresponding to 10 to 30% from the top. In addition, when the absorption process is performed in a (meth) acrylic acid absorption tower of a multistage tray type, the balance obtained through the extraction process is the highest compared to the total number of stages of the (meth) acrylic acid absorption tower. From at least one stage corresponding to 10 to 30% from.
  • the balance is supplied to the point exceeding 30% from the top of the absorption tower 100, not only the absorption efficiency may be lowered, but the amount of loss of (meth) acrylic acid through the balance in the extraction process increases, etc. Overall process efficiency can be reduced. And, the weight balance of the absorption tower (100) When supplied to the point of less than 10% from the top, the absorption efficiency may be improved, but the organic by-products included in the balance can be relatively unable to be recovered in the absorption tower 100.
  • the extraction solvent supplied to the extraction column 200 may have solubility and hydrophobicity for (meth) acrylic acid.
  • the extraction solvent may be daily for a hydrophobic having a boiling point of 120 ° C or less, or from 10 to 120 ° C, or from 50 to 120 ° C.
  • the extraction solvent supplied to the extraction column 200 preferably has solubility and hydrophobicity for (meth) acrylic acid.
  • the extraction solvent preferably has a lower boiling point than (meth) acrylic acid.
  • the extraction solvent can be advantageous to operate the process in a hydrophobic solvent having a boiling point of 120 ° C or less, or from 10 to 120 ° C, or from 50 to 120 ° C.
  • the extraction solvent is benzene, toluene, xylene, n-heptane, cycloheptane, cycloheptene, 1-heptene (1) -heptene, ethyl-benzene, methyl-cyclohexane, n-butyl acetate, isobutyl acetate, isobutyl acrylate , n-propyl acetate, isopropyl acetate, methyl isobutyl ketone, 2-methyl-1 -heptene, 6-methyl -1 -heptene (6-methyl-1 -heptene), 4-methyl-1 -heptene (4-methyl-1 -heptene), 2-ethyl-1 -hexene (2-ethyl-1 -hexene), ethylcyclo Pentane (ethylcyclopentane), 2-methyl-1-hexene, 2,3-dimethylpent
  • the temperature of the aqueous (meth) acrylic acid solution to be supplied is advantageously 10 to 70 ° C in terms of ensuring extraction efficiency.
  • the extraction column 200 in the extraction process a conventional extraction column according to the liquid-liquid contacting method may be used without particular limitation.
  • the extraction column 200 may be a Karr type reciprocating plate column, a rotary-disk contactor, a Scheibel column, a Kuhni column, a spray extraction tower. tower, packed extraction tower, pulse packed column, and the like.
  • the (meth) acrylic acid extract is discharged, and the discharged extract is supplied to the distillation column 300 through the transfer line 203.
  • the remaining balance is discharged to the lower portion of the extraction column 200, and the discharged balance is recycled to a specific point of the (meth) acrylic acid absorption tower 100 through the transfer line 201.
  • the extract in addition to (meth) acrylic acid as the target compound, may include an extraction solvent, water, and organic by-products.
  • the extract in a steady state and a stable operation is performed, the extract has a (meth) acrylate, 30 to 60 parts by weight 0/0, the extraction solvent 30 to 60 parts by weight 0/0, water, 3 to 10 parts by weight 0/0, and Residual organic byproducts may be included. That is, through the extraction step (meth) acrylic acid contained in the aqueous solution of most of the water (e.g. 90 wt. 0 /. Or more of water contained in the aqueous solution) which may be recovered as a weight balance.
  • distillation conditions can be alleviated, such that polymerization reaction of (meth) acrylic acid can be minimized in the distillation process, and thus, it is possible to secure operational stability and improve recovery efficiency of (meth) acrylic acid.
  • the balance obtained from the extraction column 200 may be mostly made of water, and may not contain (meth) acrylic acid that is not extracted.
  • the weight balance may contain (meth) acrylic acid having a concentration of 15% by weight or less or 3 to 15% by weight 0 /. Loss of acrylic acid can be minimized. Distillation process
  • the feed may be a (meth) acrylic acid extract supplied from the above-described extraction process.
  • the feed is supplied to the distillation column 300 through the (meth) acrylic acid extract transfer line 203, as shown in FIG.
  • the previous (meth) acrylic acid recovery method was a method of distilling the (meth) acrylic acid aqueous solution obtained from the (meth) acrylic acid absorption tower 100 by supplying it to the distillation column 300.
  • the (meth) acrylic acid aqueous solution is supplied to the (meth) acrylic acid extraction column 200 and extracted, and through this the distillation column 300 extracts the minimized water content.
  • the distillation method Thereby, the processing burden in a distillation process can be reduced.
  • the degree of silver near the extract introduction portion can be kept low in the distillation column 300, so that the reaction reaction of distillation of (meth) acrylic acid can be minimized.
  • the feed point to which the feed is supplied is advantageously the center of the distillation column 300, preferably, 40 to 60% of the entire stage from the top of the distillation column 300 It may be any one point corresponding to.
  • the feed supplied to the distillation column 300 is brought into contact with the azeotrope introduced into the top of the distillation column 300, and is evaporated and coaxially distilled while being heated with appropriate silver.
  • the distillation is preferably carried out by azeotropic distillation.
  • the solvent applied to the azeotropic distillation method is azeotropic with water and acetic acid It is preferable that it is a hydrophobic azeotropic solvent which can be used and does not form an azeotropy with (meth) acrylic acid. And, the hydrophobic azeotropic solvent preferably has a lower boiling point than (meth) acrylic acid (eg 120 " C or lower, or 10-120 ° C., or 50-120 ° C.).
  • the hydrophobic azeotropic solvent may be benzene, toluene, xylene, ⁇ -heptane, n-heptane, cycloheptane, cy "cycloheptene, 1 1-heptene, ethyl-benzene, methyl-cyclohexane, n-butyl acetate, isobutyl acetate, isobutyl acrylate (isobutyl acrylate), n-prcpyl acetate, isopropyl acetate (is ⁇ 3propyl acetate), methyl isobutyl ketone, 2-methyl-1 -heptene (2-methyl-1- heptene), 6-methyl-1 -heptene (6-methyl-1 -heptene),
  • the hydrophobic azeotropic solvent is preferably the same as the extraction solvent of the extraction step.
  • the same kind of solvent is used in the extraction process and the distillation process as described above, at least a part of the solvent distilled from the distillation column 300 and recovered through the phase separation tank 350 is supplied to the (meth) acrylic acid extraction column 200. And can be reused as extraction solvent.
  • the top discharge of the distillation column 300 may be supplied to the phase separation tank 350 to be reused after a predetermined treatment.
  • the phase separation tank 350 is a device for separating liquid phases that are not mixed with each other by gravity or centrifugal force, and the like, and the relatively light liquid (eg, the organic phase) is relatively to the upper portion of the phase separation tank 350.
  • the heavy liquid eg, the aqueous phase
  • the top effluent of the distillation column 300 may include an organic phase including an azeotropic solvent in the phase separation tank 350. It may be separated into an aqueous phase containing water.
  • the separated organic phase can be fed to the top of the distillation column 300 and used as an azeotropic solvent. And, if necessary, at least a part of the organic phase may be supplied to the extraction column 200 and used as an extraction solvent. At least a portion of the aqueous phase separated from the phase separation tank 350 may be supplied to the (meth) acrylic acid absorption tower 100 to be used as an absorption solvent, and some may be treated with wastewater.
  • the acetic acid may be partially contained in the aqueous phase, and the concentration of acetic acid included in the aqueous phase may vary depending on the type of azeotropic solvent and the reflux ratio. Non-limiting examples, the concentration of acetic acid contained in the water phase may be 1 to 50 parts by weight 0 /., Or 2 to 40 parts by weight 0 /., Or 3 to 30 parts by weight 0/0.
  • the aqueous (meth) acrylic acid solution passes through the (meth) acrylic acid absorption tower 100, the extraction column 200, the distillation column 300, and the like, and at least a part of the (meth) acrylic acid included in the aqueous solution is a dimer. Or oligomers.
  • a conventional polymerization inhibitor may be added to the distillation column 300.
  • the bottom discharge of the distillation column 300 may include high boiling point by-products such as polymers of (meth) acrylic acid and polymerization inhibitors in addition to (meth) acrylic acid. Therefore, if necessary, a step of separating the high boiling by-products included in the lower discharge by supplying the bottom discharge of the distillation column 300 to the high boiling point by-product separation tower 400 may be performed.
  • crude (meth) acrylic acid (CAA) recovered through the above process may be obtained as a higher purity (meth) acrylic acid (HPAA) through an additional crystallization process.
  • the high boiling point by-product separation process and crystallization process, etc. may be performed under conventional conditions, the process conditions and the like are not specifically limited.
  • each of the above-described steps in the method for recovering (meth) acrylic acid can be carried out organically and continuously. And, in addition to the above-described steps, processes that can be conventionally performed before, after, or at the same time as each step It can be included and operated more.
  • each of the above-mentioned processes may be performed organically and continuously.
  • processes that may be conventionally performed before or after each process may be further performed.
  • the (meth) acrylic acid aqueous solution obtained in the (meth) acrylic acid absorption tower 100 is fed to a separate degassing column before feeding to the (meth) acrylic acid extraction column 200 to obtain low boiling point by-products (acrene lane, propion).
  • Aldehyde, acetaldehyde, formaldehyde, isopropyl acetate, etc. may be further carried out.
  • An aqueous solution inlet connected to the aqueous solution outlet of the absorption tower 100 through an aqueous solution transfer line 102, an extract outlet through which the (meth) acrylic acid extract obtained by contacting the introduced (meth) aryl acid aqueous solution and the extraction solvent is discharged; And a (meth) acrylic acid extraction column (200) provided with a balance liquid discharge port through which the balance liquid is discharged; And
  • a distillation column having an extract inlet connected to the extract liquid outlet of the extraction column 200 and an extract liquid conveying line 203, and a (meth) acrylic acid outlet through which (meth) acrylic acid obtained by distillation of the extracted extract is discharged ( 300)
  • the weight balance outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the absorption tower 100 through the weight balance transfer line 201,
  • the weight ratio of the extraction solvent to the (meth) acrylic acid aqueous solution supplied to the extraction column 200 is operated to be greater than 0.3 and less than 1.0, of (meth) acrylic acid A continuous recovery device is provided.
  • the (meth) acrylic acid absorption tower 100 is basically connected to the (meth) acrylic acid extraction column 200 through the (meth) acrylic acid aqueous solution transfer line 102. Then, the (meth) acrylic acid extraction column 200 is connected to the distillation column 300 through the (meth) acrylic acid extract liquid transfer line 203.
  • the apparatus of this embodiment is such that the balance obtained in the (meth) acrylic acid extraction column 200 is supplied to at least one point corresponding to 10 to 30 ° / ° from the top of the (meth) acrylic acid absorption tower 100. Connected balance transfer line 201.
  • the kind of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the contact efficiency of the mixed gas 1 and the absorption solvent.
  • the contact efficiency of the mixed gas 1 and the absorption solvent may be determined in consideration of the contact efficiency of the mixed gas 1 and the absorption solvent.
  • the (meth) acrylic acid absorption tower 100 may be an absorption tower of a packed column type and an absorption tower of a multistage tray type.
  • the layered column type absorption tower may include a layering agent such as a rashing ring, a pall ring, a saddle gauze, and a structured packing.
  • the extraction liquid outlet of the extraction column 200 is connected to the absorption tower 100 through the extraction liquid conveying line 201. At least one point corresponding to 10-30% from the top relative to the total packing height.
  • the extraction liquid outlet of the extraction column 200 is connected to the absorption tower (201) through the extraction liquid transport line 201. At least one end corresponding to 10 to 30 0 /.
  • the (meth) acrylic acid extraction column 200 a conventional extraction column according to the liquid-liquid contacting method may be applied without particular limitation.
  • the extraction column 200 may be a Karr type reciprocating plate column, a rotary-disk contactor, a Scheibel column, a Kuhni column, a spray extraction column. column, packed extraction column extraction towers, pulsed packed columns, and the like.
  • Distillation column 300 is a packed column or multi-stage column contain a layer premise described above therein, preferably a sieve tray column (S j eve tray column), a dual flow tray column (dual flow tray column) may have been provided with a have.
  • a sieve tray column S j eve tray column
  • a dual flow tray column dual flow tray column
  • acetic acid absorption tower 150 (meth) acrylic acid aqueous solution transfer line 102, extract liquid transfer line 203, phase separation tank 350, high boiling point by-product separation tower 400, etc. It may be one having a conventional configuration in the field.
  • preferred examples are provided to aid in understanding the present invention. However, the following examples are only for illustrating the present invention, and the present invention is not limited thereto. ⁇
  • the mixed gas obtained through the reaction reaction of propylene was prepared.
  • the composition of the mixed gas is about 16.6 weight 0 / ⁇ acrylic acid, about 0.3 weight 0 / ⁇ acetic acid, about 0.5 weight 0 / ⁇ acetic acid, about 0.3 weight 0 / ⁇ , and about 2.6 weight 0 carbon dioxide and carbon monoxide.
  • Acrylic acid absorption tower 100 is a tray tower of a total of 10 theoretical stages, the internal temperature was adjusted to 50 to 100 ° C.
  • the mixed gas was supplied to the bottom of the absorption tower 100 at a temperature of about 160 ° C. at a pressure of about 1.3 bar, and a flow rate of about 62,860 kg / h.
  • the process water which is an absorption solvent of acrylic acid was supplied from the upper end of the absorption tower 100 to the 2nd stage (2nd stage of a total of 10 stages).
  • the aqueous acrylic acid solution to lower the absorption of the tower 100 (composition: acrylic acid 66.1 weight from about 0 / acetate, about 4.2 parts by weight 0 /, and water from about 28.4 wt. 0/0, and other about 1 .3 wt. 0 /.) was obtained at a flow rate of about 15,814 kg / h.
  • the aqueous acrylic acid solution was fed to the acrylic acid extraction column 200 via a transfer line 102. Extraction process
  • Acrylic acid extraction column 200 is a tray tower of a total of five theoretical stages, the acrylic acid aqueous solution was introduced at the top.
  • the extraction liquid was obtained at the top of the extraction column 200 in a steady state, and the extraction liquid was obtained at the bottom of the extraction column 200.
  • the flow rate and concentration of each flow in steady state operation of the extraction column 200 are shown in Table 1 below.
  • the content of the acrylic acid contained in the weight balance is about 5.9 wt. 0/0
  • the content of the toluene that contains the extract was found to be about 47.3 weight 0 /.
  • the water removal rate in the extraction column 200 was measured to be about 71.8%.
  • the extract was fed to distillation column 300 via transfer line 203. Then, the balance was supplied to the second stage (second stage of the total 10 stages) from the top of the absorption tower 100 through the transfer line 201 at a flow rate of about 3000 kg / h and reused as the absorption solvent. At this time, the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 135.9 kg / h.
  • the distillation column 300 is a tray tower having a total of 20 theoretical stages, and the operating pressure was maintained at about 1 10 torr.
  • the extract is about at the position of the ninth stage from the top of the distillation column (300) Introduced at a flow rate of 23,227 kg / h.
  • a portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300.
  • toluene, water and acetic acid contained in the extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
  • the concentration of acrylic acid included in the organic layer in the phase separation tank 350 is about
  • the concentration of acrylic acid contained in the aqueous layer was found to be about 0.8 weight 0 /.
  • the energy consumed in the distillation column 300 was about 3.8 Gcal / h.
  • the energy consumed in the distillation process is about 5.8 Gcal / h.
  • the energy saving rate in the distillation column 300 according to the method of Example 1 is about 34.5%.
  • Example 2 The absorption and extraction processes were performed in the same manner as in Example 1. However, in the distillation process, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was adjusted to an excess amount than that of Example 1, and the toluene reflux flow was about 25,000 kg / h.
  • the concentration of acrylic acid included in the organic layer was about 0.6 weight 0 /.
  • the concentration of acrylic acid included in the aqueous layer was about 0.6 weight 0 /.
  • the energy consumed in the distillation column 300 is about 4.7 Gcal / h, Compared with the method without an extraction process, the energy saving rate was about 19.0 0 /.
  • Example 2 The absorption and extraction processes were performed in the same manner as in Example 1. In the distillation process, however, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was controlled to be smaller than that of Example 1, and the toluene reflux flow was about 1,000 kg / h.
  • the phase separation concentration of the acrylic acid contained in the organic layer in the tank 350 is the concentration of the acrylic acid contained in about 1.0 wt%, the aqueous layer was confirmed to be about 1.0 wt. 0/0.
  • the energy consumed in the distillation column 300 is about 3.1 Gcal / h, which shows an energy saving rate of about 46.6 0 /.
  • the absorption process was carried out in the same manner as in Example 1, except that the water obtained as the absorption solvent of acrylic acid and the weight balance obtained from the extraction process were supplied to the top of the absorption tower 100.
  • the extraction process was performed in the same manner as in Example 1, except that the weight ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to about 2.
  • the flow rate and concentration of each stream in the steady state operation of the extraction column 200 are shown in the following table.
  • Example 2 the water removal efficiency (removal rate of about 85.5%) in the extraction column 200 was superior to that of Example 1, and the content of acrylic acid included in the balance was also lowered to about 1.6 weight 0 /. The loss of acrylic acid was found to be less than in Example 1.
  • the extract was fed to distillation column 300 via transfer line 203.
  • the balance was supplied to the top of the absorption tower 100 through a transfer line 201 at a flow rate of 3000 kg / h and reused as an absorption solvent.
  • the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 73.0 kg / h. Distillation process
  • the extract was introduced at a flow rate of 43,294 kg / h from the top of the same distillation column 300 as in Example 1 to the location of the near I 9 stage. A portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300. In addition, water and acetic acid contained in the toluene : extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
  • the concentration of acrylic acid in the organic layer was about 3.1 weight 0 /.
  • the concentration of acrylic acid in the water layer was about 3.0 weight 0 /. This is higher than the concentration of acrylic acid lost to the phase separation bath 350 in Example 1. Accordingly, in the case of Comparative Example 2, toluene reflux flow was necessary in order to prevent the loss of acrylic acid.
  • the energy consumed in the distillation column 300 is about 4.7 Gcal / h, which represents an energy saving of about 19.0% compared to the case where only the absorption-distillation process is performed without the extraction process.
  • Comparative Example 2 extraction efficiency was better than that of Example 1, but the loss of acrylic acid in the distillation column was increased. Accordingly, in the case of Comparative Example 2, an excess of toluene reflux flow was required to prevent the loss of acrylic acid, and the energy consumption in the distillation process was high. In addition, in the case of Comparative Example 2, the recovery rate of acrylic acid was lower than the energy consumption compared to Example 1. Comparative Example 3
  • the absorption process was carried out in the same manner as in Example 1, except that the water obtained as the absorption solvent of acrylic acid and the weight balance obtained from the extraction process were supplied to the top of the absorption tower 100.
  • the extraction process and the distillation process were performed in the same manner as in Example 1.
  • the extraction liquid supplied to the absorption tower 100 in the extraction process was supplied to the top of the absorption tower 100 at a flow rate of 3000 kg / h to be reused as the absorption solvent.
  • the absorption process was carried out in the same manner as in Example 1 (the balance of the extraction process was supplied to the second stage of the absorption tower).
  • the extraction process was carried out in the same manner as in Example 1, except that the increase ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to about 1.
  • the flow rates and concentrations of the flows in the steady state operation of the extraction column 200 are shown in Table 4 below.
  • Example 4 the water removal efficiency (removal rate of about 77.4%) in the extraction column 200 was superior to that of Example 1 (removal rate of about 71 .8%), and the content of acrylic acid included in the balance was also used in Example. It was found to be lower than 1.
  • the extract was fed to distillation column 300 via transfer line 203.
  • the balance was supplied to the second stage of the absorption tower 100 through a transfer line 201 at a flow rate of 3000 kg / h and reused as an absorption solvent.
  • the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 95.5 kg / h.
  • the extract was introduced at a flow rate of 27,848 kg / h from the top of the same distillation column 300 as in Example 1 to the position of the ninth stage. A portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300. In addition, toluene, water and acetic acid contained in the extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
  • the toluene reflux stream supplied to the distillation column 300 was adjusted to about 29,000 kg / h in order to have the same reflux ratio (reflux ratio about 1.9) as in Example 2.
  • the concentration of acrylic acid included in the organic layer in the phase separation tank 350 is about
  • the concentration of acrylic acid in the aqueous layer was found to be about 0.7 weight 0 /. This is slightly higher than the concentration of acrylic acid lost to the phase separation bath 350 in Example 2.
  • the energy consumed in the distillation column 300 is about 5.3 Gcal / h, showing an energy saving rate of about 8.6% compared to the case where only ' absorption-distillation process is performed without the extraction process.
  • Comparative Example 4 extraction efficiency was better than that of Example 2, but the loss of acrylic acid in the distillation column was increased despite the same reflux ratio as in Example 2. In addition, in the case of Comparative Example 4, the energy consumption in the distillation step was higher than in Example 2. In addition, in Comparative Example 4, the energy saving rate of about 8.6% was shown compared to the method not including the extraction process, and the effect of introducing the extraction process was found to be insignificant. Comparative Example 5
  • the absorption process was performed by the same method as the comparative example 4 except having supplied the process water which is the absorption solvent of acrylic acid, and the extraction liquid obtained from the extraction process to the upper end of the absorption tower 100. And the extraction process and distillation process was carried out in the same manner as in Comparative Example 4.
  • the extraction liquid supplied to the absorption tower 100 in the extraction process was supplied to the top of the absorption tower 100 at a flow rate of 3000 kg / h to be reused as the absorption solvent. At this time, the amount of acrylic acid lost to the top of the absorption tower 100 is lost to 88.8 kg / h. This loss of acrylic acid is about 7% reduced compared to Comparative Example 4.
  • Comparative Example 5 in the case of Comparative Example 5, the loss of acrylic acid in the distillation column was increased despite the same reflux ratio as in Example 2. In addition, in the case of Comparative Example 5, the energy consumption in the distillation step was higher than in Example 2. In the case of Comparative Example 5, an energy saving rate of about 8.6% was shown compared to the method not including the extraction process, and the effect of introducing the extraction process was found to be insignificant. Comparative Example 6
  • the concentration of acrylic acid included in the organic layer in the phase separation tank 350 was about 1.9 weight 0 /.
  • the concentration of acrylic acid included in the aqueous layer was about 1.8 weight 0 /. It was lowered and the one-pass recovery rate of acrylic acid rose slightly to 90.1 0 /.
  • the concentration of the acrylic acid contained in the organic layer in a separating tank (350) is the concentration of the acrylic acid contained in about 1.3 wt. 0/0, the aqueous layer has been reduced as compared to about 1.2 wt. 0 /., Comparative Example 2, acrylic acid
  • the one-pass recovery rate of RH was slightly increased to 93.2 ° / °.
  • the energy consumed in the distillation column 300 is about 6.5 Gcal / h, indicating that more energy is consumed compared to the method that does not include an extraction process.

Abstract

The present invention relates to a method for continuously recovering (meth)acrylic acid and an apparatus for use in the recovery method. The method for continuously recovering (meth)acrylic acid according to the present invention can significantly reduce the amount of an extractant used and the amount of energy consumed in the entire process, can minimize the polymerization of (meth)acrylic acid during the recovery process, and thus enables the stable recovery of (meth)acrylic acid and the operation of the continuous process.

Description

【명세서】  【Specification】
【발명의 명칭】  [Name of invention]
(메트)아크릴산의 연속 회수 방법 및 장치  Continuous recovery method and apparatus of (meth) acrylic acid
【기술분야】  Technical Field
본 발명은 (메트)아크릴산의 연속 회수 방법 및 장치에 관한 것이다. The present invention relates to a method and apparatus for continuous recovery of (meth) acrylic acid.
【배경기술】 Background Art
(메트)아크릴산은 일반적으로 프로판, 프로필렌, (메트)아크롤레인 등의 화합물을 촉매 존재 하에서 기상 산화 반웅시키는 방법으로 제조된다. 예를 들어， 반웅기 내에 적절한 촉매의 존재 하에 프로판, 프로필렌 등은 기상 산화 반웅에 의해. (메트)아크를레인을 거쳐 (메트)아크릴산으로 전환되고, 반응기 후단에서 (메트)아크릴산， 미반응 프로판 또는 프로필렌， (메트)아크를레인, 불활성 가스, 이산화탄소, 수증기, 및 상기 반웅에 의한 각종 유기 부산물 (초산, 저비점 부산물, 고비점 부산물 등)을 포함하는 반웅 생성물 흔합 가스가 얻어진다.  (Meth) acrylic acid is generally prepared by a method of reacting gas phase oxidation in the presence of a catalyst with compounds such as propane, propylene and (meth) acrolein. For example, propane, propylene and the like are reacted by gas phase oxidation reaction in the presence of a suitable catalyst in the reaction. It is converted into (meth) acrylic acid via (meth) arklane, and (meth) acrylic acid, unreacted propane or propylene, (meth) arklane, inert gas, carbon dioxide, water vapor, and various reactions by the reaction at the rear end of the reactor. A reaction product mixed gas is obtained that includes organic byproducts (acetic acid, low boiling byproducts, high boiling byproducts, and the like).
상기 (메트)아크릴산 함유 흔합 가스는 (메트)아크릴산 흡수탑에서 공정수 등의 흡수 용제와 접촉되어 (메트)아크릴산 수용액으로 회수된다. 그리고， (메트)아크릴산이 탈기된 비용해성 가스는 (메트)아크릴산의 합성반응으로 재순환되고， 일부는 소각되어 배출된다. 그리고, 통상적으로 상기 (메트)아크릴산 수용액은 증류 및 정제되어 (메트)아크릴산으로 수득된다.  The said (meth) acrylic acid containing mixed gas is contacted with absorption solvents, such as process water, in a (meth) acrylic acid absorption tower, and is collect | recovered by the (meth) acrylic-acid aqueous solution. Then, the insoluble gas from which (meth) acrylic acid is degassed is recycled to the synthesis reaction of (meth) acrylic acid, and part of it is incinerated and discharged. In general, the (meth) acrylic acid aqueous solution is distilled and purified to obtain (meth) acrylic acid.
한편, 공정 조건 또는 공정 순서 등을 조절하여 (메트)아크릴산의 회수 효율을 향상시키는 다양한 방법들이 제안되고 있다. 대표적으로ᅳ (메트)아크릴산 흡수탑에서 얻어진 (메트)아크릴산 수용액으로부터 물과 초산을 분리하기 위한 방법으로, 증류 컬럼에서 소수성 용매를 사용하여 공비 증류하는 방법이 알려져 있다. 상기 공비 증류법은 소수성 용매를 사용한 증류 공정을 통해, (메트)아크릴산 합성반웅의 주요 부산물인 초산을 물과 함께 회수함으로써，(메트)아크릴산을 효과적으로 회수하는 방법이다. 특히， 본 발명의 발명자들은 대한민국 공개특허 제 2009-0041355호를 통해, 증류 컬럼에서 소수성 용매를 사용하고, 증류 컬럼 상부로 회수되는 초산 함유 폐수를 (메트)아크릴산 흡수탑으로 순환시켜 재사용하는 방법을 제안한 바 있다. 이처럼 증류 컬럼에서의 공비 증류법은 폐수량을 줄임과 동시에， 유기물의 유입올 효과적으로 억제할 수 있고， 이후의 정제 단계를 간소화할 수 있는 효과를 갖는다. On the other hand, various methods have been proposed to improve the recovery efficiency of (meth) acrylic acid by adjusting the process conditions or the process sequence. Representatively, a method of azeotropic distillation using a hydrophobic solvent in a distillation column is known as a method for separating water and acetic acid from an aqueous (meth) acrylic acid solution obtained in a (meth) acrylic acid absorption tower. The azeotropic distillation method is a method of effectively recovering (meth) acrylic acid by recovering acetic acid, which is a main by-product of (meth) acrylic acid synthesis reaction, with water through a distillation process using a hydrophobic solvent. In particular, the inventors of the present invention through the Republic of Korea Patent Publication No. 2009-0041355, using a hydrophobic solvent in the distillation column, and recycling the acetic acid-containing wastewater recovered to the top of the distillation column to the (meth) acrylic acid absorption tower for reuse I have suggested. As described above, the azeotropic distillation method in the distillation column can reduce the amount of wastewater, effectively suppress the inflow of organic matter, and simplify the subsequent purification step.
하지만， 상기 공비 증류법 및 이전에 개시된 (메트)아크릴산의 회수 방법들은 (메트)아크릴산 수용액을 증류하는 공정에서 매우 많은 양의 에너지가 소비될 뿐만 아니라， 증류 공정의 처리 부담이 높고, 그 과정에서 (메트)아크릴산의 중합에 의한 고분자 생성으로 인해 정상 운전이 불가능해지는 등 공정 운전의 안정성이 떨어지는 문제점이 있다.  However, the azeotropic distillation method and the previously described method of recovering (meth) acrylic acid not only consume a large amount of energy in the process of distilling an aqueous (meth) acrylic acid solution, but also have a high processing burden of the distillation process. Due to the polymer production by the polymerization of meth) acrylic acid there is a problem that the stability of the process operation is inferior, such as normal operation is impossible.
【발명의 내용】  [Content of invention]
【해결하려는 과제】  [Problem to solve]
본 발명은 에너지 소비량을 현저히 낮출 수 있으면서도 안정적인 (메트)아크릴산의 회수와 연속 공정의 운용을 가능케 하는 (메트)아크릴산의 연속 회수 방법을 제공하기 위한 것이다.  The present invention is to provide a method for continuous recovery of (meth) acrylic acid, which can significantly reduce energy consumption and enable stable recovery of (meth) acrylic acid and operation of a continuous process.
또한， 본 발명은 상기 (메트)아크릴산의 연속 회수에 이용 가능한 장치를 제공하기 위한 것이다.  Moreover, this invention is providing the apparatus which can be used for the continuous collection | recovery of the said (meth) acrylic acid.
【과제의 해결 수단】  [Measures of problem]
본 발명에 따르면，  According to the invention,
(메트)아크릴산의 합성반응에 의해 생성된 (메트)아크릴산, 유기 부산물 및 수증기를 포함하는 흔합 가스를 (메트)아크릴산 흡수탑에서 물과 접촉시켜 (메트)아크릴산 수용액을 얻는 흡수 공정;  An absorption step of obtaining a (meth) acrylic acid aqueous solution by contacting a mixed gas containing (meth) acrylic acid, organic by-products and water vapor produced by the synthesis reaction of (meth) acrylic acid with water in a (meth) acrylic acid absorption tower;
상기 흡수 공정을 통해 수득된 (메트)아크릴산 수용액을 추출 컬럼에서 추출 용매와 접촉시켜 (메트)아크릴산 추출액과 추잔액을 얻는 추출 공정; 및  An extraction step of bringing the (meth) acrylic acid aqueous solution obtained through the absorption step into contact with an extraction solvent in an extraction column to obtain a (meth) acrylic acid extract and a balance solution; And
상기 추출 공정을 통해 수득된 (메트)아크릴산 추출액을 포함하는 피드 (feed)를 증류하여 (메트)아크릴산을 얻는 증류 공정을 포함하고,  A distillation process of distilling a feed including a (meth) acrylic acid extract obtained through the extraction process to obtain (meth) acrylic acid,
상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 최상부로부터 10 내지 30%에 해당하는 적어도 어느 한 지점으로 공급되고，  The balance obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the (meth) acrylic acid absorption tower,
상기 추출 컬럼에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1.0 미만인, (메트)아크릴산의 연속 회수 방법이 제공된다. The weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column is more than 0.3 and less than 1.0, the continuous recovery method of (meth) acrylic acid Is provided.
본 발명에 따르면， 상기 흡수 공정은 층진 컬럼 타입 (packed column type)의 (메트)아크릴산 흡수탑에서 수행되고, 상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점으로 공급될 수 있다.  According to the present invention, the absorption process is performed in a packed column type (meth) acrylic acid absorption tower, and the balance obtained through the extraction process is compared with the total packing height of the (meth) acrylic acid absorption tower. It may be supplied to at least one point corresponding to 10 to 30% from the top.
또한, 본 발명에 따르면， 상기 흡수 공정은 멀티스테이지 트레이 타입 (multistage tray type)의 (메트)아크릴산 흡수탑에서 수행되고, 상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 단 수 대비 최상단으로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 단으로 공급될 수 있다. In addition, according to the present invention, the absorption process is carried out in the (meth) acrylic acid absorption tower of the multistage tray type (multistage tray type), the balance obtained through the extraction process is the total of the (meth) acrylic acid absorption tower It may be supplied to at least one stage corresponding to 10 to 30 0 /.
그리고, 상기 추출 용매는 10 내지 120 °C의 끓는 점을 갖는 소수성 용매일 수 있다.  In addition, the extraction solvent may be a hydrophobic solvent having a boiling point of 10 to 120 ° C.
그리고， 상기 추출 공정을통해 수득된 추출액은 30 내지 60 중량 %의 (메트)아크릴산， 30 내지 60 증량 0/。의 추출 용매, 3 내지 10 중량0 /。의 물， 및 잔량의 유기 부산물올 포함할 수 있다. In addition, the extract obtained through the extraction process includes 30 to 60% by weight of (meth) acrylic acid, 30 to 60% by weight of 0 /。 extraction solvent, 3 to 10% by weight 0 /。 water, and the remaining amount of organic by-products can do.
또한， 상기 추출 공정을 통해 수득된 추잔액은 (메트)아크릴산을 15 중량0 /0 이하로 포함할 수 있다. Further, the weight balance of a (meth) acrylic acid obtained through the extraction process may comprise less than 15 wt. 0/0.
한편, 본 발명에 따르면，  On the other hand, according to the present invention,
(메트)아크릴산의 합성반웅에 의해 생성된 (메트)아크릴산, 유기 부산물 및 수증기를 포함하는 혼합 가스가 공급되는 흔합 가스 유입구와, 상기 흔합 가스와 물의 접촉에 의해 수득되는 (메트)아크릴산 수용액이 배출되는 수용액 배출구가 구비된 (메트)아크릴산 흡수탑 (100);  A mixed gas inlet to which a mixed gas containing (meth) acrylic acid, organic by-products and water vapor produced by the synthesis reaction of (meth) acrylic acid is supplied, and an aqueous (meth) acrylic acid solution obtained by contacting the mixed gas with water are discharged. (Meth) acrylic acid absorption tower 100 is provided with an aqueous solution outlet;
상기 흡수탑 (100)의 수용액 배출구와 수용액 이송 라인 (102)을 통해 연결된 수용액 유입구, 유입된 (메트)아릴산 수용액과 추출 용매의 접촉에 의해 수득되는 (메트)아크릴산 추출액이 배출되는 추출액 배출구, 및 그 추잔액이 배출되는 추잔액 배출구가 구비된 (메트)아크릴산 추출 컬럼 (200); 상기 추출 컬럼 (200)의 추출액 배출구와 추출액 이송 라인 (203)을 통해 연결된 추출액 유입구와， 유입된 추출액의 증류에 의해 수득되는 (메트)아크릴산이 배출되는 (메트)아크릴산 배출구가 구비된 증류 컬럼 (300)을 포함하고, The aqueous solution inlet of the absorption tower 100 and the aqueous solution inlet connected through the aqueous solution transfer line 102, the extraction liquid outlet through which the (meth) acrylic acid extract obtained by contacting the introduced (meth) aryl acid aqueous solution and the extraction solvent, And a (meth) acrylic acid extraction column (200) provided with a balance liquid discharge port through which the balance liquid is discharged; The distillation is provided with an extract inlet of the extraction column 200 and an extract inlet connected through an extract transfer line 203 and a (meth) acrylic acid outlet through which (meth) acrylic acid obtained by distillation of the extracted extract is discharged. Column 300,
상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 최상부로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 지점에 연결되고 The extraction liquid outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the absorption tower 100 through the extraction liquid conveying line 201 and
상기 추출 컬럼 (200)에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1.0 미만이 되도록 운전되는, (메트)아크릴산의 연속 회수 장치가 제공된다.  A continuous recovery apparatus of (meth) acrylic acid is provided, which is operated so that the weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column 200 is greater than 0.3 and less than 1.0.
본 발명에 따르면, 상기 (메트)아크릴산 흡수탑 (100)은 층진 컬럼 타입 (packed column type)의 흡수탑이고， 상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점에 연결될 수 있다.  According to the present invention, the (meth) acrylic acid absorption tower 100 is a absorption column of a packed column type, and the extraction liquid outlet of the extraction column 200 is connected to the extraction liquid conveying line 201. It may be connected to at least one point corresponding to 10 to 30% from the top of the total packing height of the absorption tower 100.
또한, 본 발명에 따르면, 상기 (메트)아크릴산 흡수탑 (100)은 멀티스테이지 트레이 타입 (multistage tray type)의 흡수탑이고, 상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 단 수 대비 최상단으로부터 10 내지 30 °/。에 해당하는 적어도 어느 한 단에 연결될 수 있다.  In addition, according to the present invention, the (meth) acrylic acid absorption tower 100 is a multistage tray type absorption tower, and the extraction liquid outlet of the extraction column 200 is the extraction liquid transport line 201. Through the absorption tower 100 may be connected to at least one end corresponding to 10 to 30 ° / ° from the top of the total number of stages.
【발명의 효과】  【Effects of the Invention】
본 발명에 따른 (메트)아크릴산의 연속 회수 방법은 추출 용매의 사용량과 전체 공정의 에너지 소비량을 현저히 낮출 수 있고, 회수 과정에서 (메트)아크릴산의 중합 반웅을 최소화할 수 있어, 안정적인 (메트)아크릴산의 회수와 연속 공정의 운용을 가능케 한다.  The continuous recovery method of (meth) acrylic acid according to the present invention can significantly reduce the amount of the extraction solvent and the energy consumption of the entire process, and minimize the polymerization reaction of (meth) acrylic acid in the recovery process, thereby making it stable (meth) acrylic acid. It allows for the recovery and operation of continuous processes.
【도면의 간단한 설명】  [Brief Description of Drawings]
도 1은 본 발명의 일 구현 예에 따른 (메트)아크릴산의 연속 회수 방법 및 장치를 모식적으로 나타낸 것이다.  1 schematically illustrates a method and apparatus for continuously recovering (meth) acrylic acid according to one embodiment of the present invention.
<부호의 설명 >  <Description of the sign>
1 : (메트)아크릴산 함유 흔합 가스 100: (메트)아크릴산 흡수탑 102: (메트)아크릴산 수용액 이송 라인 150: 초산 흡수탑  DESCRIPTION OF SYMBOLS 1: (meth) acrylic acid containing mixed gas 100: (meth) acrylic acid absorption tower 102: (meth) acrylic acid aqueous solution transfer line 150: acetic acid absorption tower
200: (메트)아크릴산 추출 컬럼 201 : 추잔액 이송 라인  200: (meth) acrylic acid extraction column 201: balance liquid transfer line
203: 추출액 이송 라인 300: 증류 컬럼 350: 상 분리조 400: 고비점 부산물 분리탑 203: extract liquid transfer line 300: distillation column 350: phase separation tank 400: high boiling point by-product separation tower
CAA: 크루드 (메트)아크릴산 HPAA: 고순도 (메트)아크릴산 CAA: Crude (meth) acrylic acid HPAA: High purity (meth) acrylic acid
【발명을 실시하기 위한 구체적인 내용】 [Specific contents to carry out invention]
이하, 본 발명의 구현 예들에 따른 (메트)아크릴산의 연속 회수 방법 및 회수 장치에 대하여 설명하기로 한다.  Hereinafter, a method and a recovery apparatus for the continuous recovery of (meth) acrylic acid according to embodiments of the present invention will be described.
그에 앞서, 본 명세서에 사용되는 전문 용어는 단지 특정 구현예를 언급하기 위한 것이며, 본 발명을 한정하는 것을 의도하지 않는다. 그리고, 여기서 사용되는 단수 형태들은 문구들이 이와 명백히 반대의 의미를 나타내지 않는 한 복수 형태들도 포함한다. 또한, 명세서에서 사용되는 '포함 '의 의미는 특정 특성， 영역, 정수， 단계, 동작， 요소 또는 성분을 구체화하며, 다른 특정 특성, 영역, 정수， 단계, 동작, 요소, 또는 성분의 부가를 제외시키는 것은 아니다.  Prior to this, the terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. In addition, the meaning of "included" as used in the specification specifies a specific characteristic, region, integer, step, operation, element or component, excluding the addition of other specific characteristic, region, integer, step, operation, element, or component. I don't mean
그리고, 본 명세서 전체에서 명시적인 언급이 없는 한， 몇 가지 용어들은 다음과 같은 의미로 정의된다.  And, unless stated otherwise throughout this specification, some terms are defined as follows.
'(메트)아크릴산'이라 함은 아크릴산 (acrylic acid), 메타크릴산 (methacrylic acid) 또는 이들의 흔합물을 통칭하는 의미로 사용될 수 있다.  '(Meth) acrylic acid' may be used to mean acrylic acid, methacrylic acid, or a combination thereof.
'(메트)아크릴산 함유 흔합 가스'라 함은 기상 산화 반웅에 의해 (메트)아크릴산을 합성할 때 생성될 수 있는 흔합 가스를 통칭한다. 비제한적인 예로, 프로판, 프로필렌， 부탄， 아이소부틸렌 및 (메트)아크롤레인으로 이루어진 군에서 선택되는 1종 이상의 화합물 ('원료 화합물')을 촉매 존재 하에서 기상 산화 반웅시키는 방법으로 상기 (메트)아크릴산 함유 흔합 가스를 얻을 수 있다. 이때， 상기 (메트)아크릴산 함유 흔합 가스에는 (메트〉아크릴산, 미반웅 원료 화합물， (메트)아크를레인, 블활성 가스, 일산화탄소, 이산화탄소 수증기, 및 각종 유기 부산물 (초산ᅳ 저비점 부산물 (light ends), 고비점 부산물 (heavies) 등) 등이 포함될 수 있다. 여기서, '저비점 부산물 '(light ends) 또는 '고비점 부산물 '(heavies)이라 함은 목적하는 (메트)아크릴산의 제조 및 회수 공정에서 생성될 수 있는 부산물의 일종으로서， 분자량이 (메트)아크릴산 보다 작거나 큰 화합물들을 통칭한다. 그리고, 상기 유기 부산물에 의해 형성되는 난수용성 부유물을 '스컴 '(scum)이라 한다. The term "(meth) acrylic acid-containing mixed gas" refers to a mixed gas that can be produced when synthesizing (meth) acrylic acid by vapor phase oxidation reaction. As a non-limiting example, the (meth) acrylic acid may be reacted by vapor phase oxidation of at least one compound selected from the group consisting of propane, propylene, butane, isobutylene and (meth) acrolein ('raw compound') in the presence of a catalyst. A mixed gas containing can be obtained. At this time, the (meth) acrylic acid-containing mixed gas includes (meth> acrylic acid, unbanung raw material compound, (meth) aclein, activating gas, carbon monoxide, carbon dioxide vapor, and various organic by-products (light acetate and low boiling point by-products (light ends)). , High boiling point by-products (heavies, etc.), etc. Here, the term 'light ends' or 'high boiling point by-products' (heavies) may be generated in the manufacturing and recovery process of the desired (meth) acrylic acid. As a by-product, a compound having a molecular weight of less than or greater than (meth) acrylic acid may be referred to collectively, and a poorly water-soluble float formed by the organic by-product It is called 'scum'.
'(메트)아크릴산 수용액 '은 (메트)아크릴산을 함유한 수용액으로서， 예를 들면 상기 (메트)아크릴산 함유 흔합 가스를 물을 포함한 흡수 용제와 접촉시키는 방법으로 수득될 수 있다.  '(Meth) acrylic acid aqueous solution' is an aqueous solution containing (meth) acrylic acid, and can be obtained by, for example, contacting the (meth) acrylic acid-containing mixed gas with an absorption solvent containing water.
'피드 '(feed)라 함은 추출하고자 하는 용질 (solute)을 함유한 액체 흔합물을 의미하는 것으로서， 추출 용매 (extraction solvent)에 대하여 가용성을 갖는 용질과 가용성을 갖지 않는 기타 성분 (inert material)의 흔합물일 수 있다. 여기서, 상기 피드에 상기 추출 용매를 가하면 물질 전달 현상에 의해 상기 용질이 피드로부터 추출 용매로 용해된다. 그에 따라, 상당량의 용질이 용해된 추출 용매는 추출액 (extract s ution)을 형성하고， 용질의 상당량을 잃은 피드는 추잔액 (raffinate solution)을 형성한다.  'Feed' means a liquid mixture containing a solute to be extracted, and a solute that is soluble in an extraction solvent and an inert material that is not soluble. It may be a complex of. Here, when the extraction solvent is added to the feed, the solute is dissolved from the feed into the extraction solvent by mass transfer. Accordingly, the extraction solvent in which a significant amount of solute is dissolved forms an extract solution, and the feed that loses a significant amount of solute forms a traffic solution.
한편, Karr 타입 컬럼, Scheibel 타입 컬럼과 같은 애지테이티드 컬럼 (agitated cc)lumns)을 이용한 액-액 추출 (liquid-liquid extraction)에 있어서， 상대적으로 가벼운 상 (light phase)은 추출 컬럼의 하단으로 공급되고， 상대적으로 무거운 상 (heavy phase)은 추출 컬럼의 상단으로 공급된다. 그리고, 상기 추출 컬럼에 공급된 물질들의 접촉에 의해 추출이 진행되어， 새로운 조성의 가벼운 상과 무거운 상이 얻어진다. 상기 추출 과정을 통해 얻어지는 새로운 조성의 가벼운 상은 추출 컬럼의 상부 배출구를 통해 수득되고， 새로운 조성의 무거운 상은 추출 컬럼의 하부 배출구를 통해 수득된다. 일반적으로， 상기 추출 과정을 통해 얻어지는 새로운 조성의 무거운 상은, 추출 컬럼의 하부 배출구로 배출되기 전에, 추출 컬럼의 하부에 일정 수준으로 정치된 상태를 유지하며, 그 중 일부가 추출 컬럼의 하부 배출구로 배출된다. 이때, 상기 무거운- 상이 정치되어 있는 추출 컬럼의 구간을 하부 정치 구간' (또는 무거운 상의 '정치 구간ᅳ)이라 한다. 예를 들어， 추출 용매를 사용하여 (메트)아크릴산 수용액에 포함된 (메트)아크릴산을 추출하는 공정에 있어서, 상대적으로 무거운 상인 (메트)아크릴산 수용액은 추출 컬럼의 상단으로 공급되고， 상대적으로 가벼운 상인 추출 용매는 추출 컬럼의 하단으로 공급된다. 그리고， 이들의 접촉에 의해 추출이 진행되어, 상당량의 (메트)아크릴산이 용해된 추출액 (extract solution)과 (메트)아크릴산의 상당량을 잃은 추잔액 (raffinate solution)이 얻어진다. 이때， 상대적으로 가벼운 상인 상기 추출액은 추출 컬럼의 상부 배출구를 통해 수득되고 상대적으로 무거운 상인 상기 추잔액은 추출 컬럼의 하부 배출구를 통해 수득된다. On the other hand, in liquid-liquid extraction using agitated cc columns such as Karr type columns and Scheibel type columns, a relatively light phase is applied to the bottom of the extraction column. The relatively heavy phase is fed to the top of the extraction column. The extraction proceeds by contacting the materials supplied to the extraction column, whereby a light phase and a heavy phase of a new composition are obtained. The light phase of the new composition obtained through the extraction process is obtained through the top outlet of the extraction column, and the heavy phase of the new composition is obtained through the bottom outlet of the extraction column. In general, the heavy phase of the new composition obtained through the extraction process remains at a fixed level at the bottom of the extraction column, before being discharged to the bottom outlet of the extraction column, some of which are directed to the bottom outlet of the extraction column. Discharged. At this time, the section of the extraction column in which the heavy-phase is stationary is referred to as the lower stationary section (or the “political section” of the heavy phase). For example, in the process of extracting (meth) acrylic acid contained in an aqueous (meth) acrylic acid solution using an extraction solvent, a relatively heavy phase (meth) acrylic acid aqueous solution is supplied to the top of the extraction column, and a relatively light phase The extraction solvent is fed to the bottom of the extraction column. Then, the extraction proceeds by contacting these, and the extract solution in which a considerable amount of (meth) acrylic acid is dissolved and the extract solution in which a considerable amount of (meth) acrylic acid is lost are obtained. Obtained. At this time, the relatively light phase of the extract is obtained through the top outlet of the extraction column and the relatively heavy phase of the extract is obtained through the bottom outlet of the extraction column.
이하， 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자가 본 발명을 쉽게 실시할 수 있도록, 첨부한 도면을 참조하여 본 발명의 구현 예들에 대하여 상세히 설명한다. 다만， 본 발명은 여러 가지 상이한 형태들로 구현될 수 있으며 여기에서 설명하는 구현 예들만으로 한정되지 않는다. 한편, 본 발명자들은 (메트)아크릴산의 연속 회수 방법에 대한 연구 과정에서， 이전에 개시된 공비 증류법을 통한 (메트)아크릴산의 회수 방법은 증류 공정에 매우 많은 양의 에너지가 소비될 뿐만 아니라， 증류 과정에서 (메트)아크릴산의 중합에 의한 고분자 생성으로 인해 공정 운전의 안정성이 떨어지는 문제점이 확인되었다.  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. On the other hand, the present inventors in the study of the continuous recovery method of (meth) acrylic acid, the method of recovering (meth) acrylic acid through the azeotropic distillation method disclosed previously not only consumes a large amount of energy in the distillation process, Due to the polymer production by the polymerization of (meth) acrylic acid in the problem of the stability of the process operation was found to be poor.
이에， 본 발명자들의 계속적인 연구 결과, 도 1과 같이 Accordingly, as a result of the continuous study of the inventors, as shown in FIG.
(메트)아크릴산의 흡수 공정과 증류 공정의 사이에 (메트)아크릴산 추출 공정을 도입할 경우 증류 공정의 운용 부담을 현저히 낮출 수 있음이 확인되었다. 나아가, 상기 추출 공정의 추잔액을 (메트)아크릴산 흡수탑의 특정 지점으로 공급함과 동시에, 상기 추출 공정에서의 (메트)아크릴산 수용액에 대한 추출 용매의 중량비를 조절할 경우， (메트)아크릴산의 회수율 대비 에너지 소비량을 현저히 낮출 수 있고， 보다 안정적인 연속 공정의 운용이 가능함이 확인되었다. It was confirmed that when the (meth) acrylic acid extraction step is introduced between the absorption step of the (meth) acrylic acid and the distillation step, the operation burden of the distillation step can be significantly reduced. Furthermore, when supplying the balance of the extraction process to a specific point of the (meth) acrylic acid absorption tower, and adjusting the weight ratio of the extraction solvent to the aqueous (meth) acrylic acid in the extraction process, compared to the recovery rate of (meth) acrylic acid It has been found that energy consumption can be significantly lowered and that a more stable continuous process can be operated.
I. (메트)아크릴산의 연속회수방법 I. Continuous recovery method of (meth) acrylic acid
이러한 발명의 일 구현 예에 따르면，  According to one embodiment of this invention,
(메트)아크릴산의 합성반응에 의해 생성된 (메트)아크릴산， 유기 부산물 및 수증기를 포함하는 흔합 가스를 (메트)아크릴산 흡수탑에서 물과 접촉시켜 (메트)아크릴산 수용액을 얻는 흡수 공정;  An absorption step of obtaining a (meth) acrylic acid aqueous solution by contacting a mixed gas containing (meth) acrylic acid, organic by-products and water vapor produced by the synthesis reaction of (meth) acrylic acid with water in a (meth) acrylic acid absorption tower;
상기 흡수 공정을 통해 수득된 (메트)아크릴산 수용액을 추출 컬럼에서 추출 용매와 접촉시켜 (메트)아크릴산 추출액과 추잔액을 얻는 추출 공정; 및 The (meth) acrylic acid aqueous solution obtained through the absorption process was contacted with an extraction solvent in an extraction column to obtain a (meth) acrylic acid extract and an extract. Extraction process; And
상기 추출 공정을 통해 수득된 (메트)아크릴산 추출액을 포함하는 피드 (feed)를 증류하여 (메트)아크릴산을 얻는 증류 공정을 포함하고，  A distillation process of distilling a feed including a (meth) acrylic acid extract obtained through the extraction process to obtain (meth) acrylic acid,
상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 최상부로부터 10 내지 30%에 해당하는 적어도 어느 한 지점으로 공급되고，  The balance obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the (meth) acrylic acid absorption tower,
상기 추출 컬럼에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1.0 미만인, (메트)아크릴산의 연속 회수 방법이 제공된다.  A method for continuous recovery of (meth) acrylic acid is provided, wherein the weight ratio of the extraction solvent to the aqueous (meth) acrylic acid solution supplied to the extraction column is greater than 0.3 and less than 1.0.
이하, 도 1을 참고하여， 발명의 구현 예에 포함될 수 있는 각 공정에 대하여 설명한다.  Hereinafter, with reference to FIG. 1, each process that can be included in the embodiment of the invention will be described.
(흡수공정) (Absorption process)
흡수 공정은 (메트)아크릴산 수용액을 얻기 위한 공정으로서， (메트)아크릴산의 합성반응을 통해 얻은 (메트)아크릴산 함유 흔합 가스를 물을 포함한 흡수 용제와 접촉시키는 방법으로 수행될 수 있다.  The absorption step is a step for obtaining an aqueous (meth) acrylic acid solution, and may be performed by contacting a (meth) acrylic acid-containing mixed gas obtained through a synthesis reaction of (meth) acrylic acid with an absorption solvent including water.
비제한적인 예로, 상기 (메트)아크릴산의 합성반웅은 프로판， 프로필렌, 부탄, 아이소부틸렌, 및 (메트)아크를레인으로 이루어진 군에서 선택되는 1종 이상의 화합물을 기상 촉매 하에서 산화 반웅시키는 방법으로 수행될 수 있다. 이때, 상기 기상 산화 반응은 통상적인 구조의 기상 산화 반웅기 및 반웅 조건 하에서 진행될 수 있다. 상기 기상 산화 반웅에서의 촉매 또한 통상적인 것이 사용될 수 있으몌 예를 들어 대한민국 등록특허 제 0349602 호 및 제 037818 호에 개시된 촉매 등이 사용될 수 있다. 상기 기상 산화 반웅에 의해 생성되는 (메트)아크릴산 함유 흔합 가스에는 목적 생성물인 (메트)아크릴산 이외에, 미반응 원료 화합물， 중간체인 (메트)아크를레인， 불활성 가스, 이산화탄소, 수증기, 및 각종 유기 부산물 (초산, 저비점 부산물， 고비점 부산물 등)이 포함되어 있을 수 있다.  As a non-limiting example, the synthesis reaction of (meth) acrylic acid may be performed by oxidizing reaction of at least one compound selected from the group consisting of propane, propylene, butane, isobutylene, and (meth) acrelane under a gas phase catalyst. Can be performed. In this case, the gas phase oxidation reaction may be performed under a gas phase oxidation reaction and reaction conditions of a conventional structure. Conventional catalysts in the gas phase oxidation reaction may also be used. For example, the catalysts disclosed in Korean Patent Nos. 0349602 and 037818 may be used. The (meth) acrylic acid-containing mixed gas produced by the gas phase oxidation reaction includes, in addition to (meth) acrylic acid as the target product, unreacted raw material compound, intermediate (meth) acrelane, inert gas, carbon dioxide, water vapor, and various organic byproducts. (Acetic acid, low boiling by-products, high boiling by-products, etc.).
그리고, 도 1을 참조하면, 상기 (메트)아크릴산 수용액은 (메트)아크릴산 함유 흔합 가스 (1 )를 (메트)아크릴산 흡수탑 (100)에 공급하여, 물을 포함한 흡수 용제와 접촉시키는 방법으로 얻어질 수 있다. 여기서, (메트)아크릴산 흡수탑 (100)의 종류는 상기 흔합 가스 (1 )와 흡수 용제의 접촉 효율 등을 감안하여 결정될 수 있다. 비제한적인 예로，1, the (meth) acrylic acid aqueous solution is obtained by supplying a (meth) acrylic acid-containing mixed gas (1) to the (meth) acrylic acid absorption tower 100 and contacting with an absorption solvent containing water. Can lose. Here, the type of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the contact efficiency of the mixed gas 1 and the absorption solvent. As a non-limiting example,
(메트)아크릴산 흡수탑 (100)은 층진 컬럼 타입 (packed column type)의 흡수탑, 멀티스테이지 트레이 타입 (multistage tray type)의 흡수탑일 수 있다. 상기 층진 컬럼 타입의 흡수탑은 내부에 래성 링 (rashing ring), 폴 링 (pall ring), 새들 (saddle), 거즈 (gauze), 스트럭쳐 패킹 (structured packing) 등의 층진제가 적용된 것일 수 있다. The (meth) acrylic acid absorption tower 100 may be an absorption tower of a packed column type and an absorption tower of a multistage tray type. The layered column type absorption tower may include a layering agent such as a rashing ring, a pall ring, a saddle, a gauze, and a structured packing.
그리고， 상기 흡수 공정의 효율을 고려하여, 상기 흔합 가스 (1 )는 흡수탑 (100)의 하부로 공급될 수 있고 물을 포함한 흡수 용제는 흡수탑 (100)의 상부로 공급될 수 있다.  In addition, in consideration of the efficiency of the absorption process, the mixed gas 1 may be supplied to the lower portion of the absorption tower 100, and the absorption solvent including water may be supplied to the upper portion of the absorption tower 100.
상기 흡수 용제는 수듯물, 탈이온수 등의 물을 포함할 수 있으며， 다른 공정으로부터 도입되는 순환 공정수 (예를 들어, 추출 공정 및 /또는 증류 공정으로부터 재순환되는 수상)를 포함할 수 있다. 그리고, 상기 흡수 용제에는 다른 공정으로부터 도입되는 미량의 유기 부산물 (예를 들어 초산)이 포함되어 있을 수 있다. 다만, (메트)아크릴산의 흡수 효율을 고려하여， 상기 흡수탑 (100)에 공급되는 흡수 용제 (특히 상기 순환 공정수)에는 유기 부산물이 15 증량0 /。 이하로 포함되도록 하는 것이 바람직하다. The absorption solvent may include water such as scum water, deionized water and the like, and may include circulating process water introduced from another process (eg, an aqueous phase recycled from an extraction process and / or a distillation process). In addition, the absorption solvent may contain a trace amount of organic by-products (for example, acetic acid) introduced from another process. However, in consideration of the absorption efficiency of (meth) acrylic acid, the absorption solvent (particularly, the circulating process water) supplied to the absorption tower 100 is preferably such that an organic by-product is included in an amount of 15 increase of 0 / ° or less.
나아가, 발명의 구현 예에 따르면 후술할 (메트)아크릴산 추출 컬럼 (200)에서 수득된 추잔액은 (메트)아크릴산 흡수탑 (100)으로 재순환되어 흡수 용제로써 사용될 수 있다. 특히, 상기 추잔액은 상기 흡수탑 (100)의 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점으로 공급되도록 하는 것이 공정 효율의 향상 측면에서 보다 유리하다. 이에 관한 내용은 (메트)아크릴산 추출 컬럼 (200)에 대한 설명 부분에서 상술한다. 한편, (메트)아크릴산 흡수탑 (100)은 (메트)아크릴산의 웅축 조건 및 포화 수증기압에 따른 수분 함유량 등을 고려하여, 1 내지 1.5 bar 또는 1 내지 1.3 bar의 내부 압력, 50 내지 100 °C 또는 50 내지 80 °C의 내부 온도 하에서 운전될 수 있다. Furthermore, according to the embodiment of the present invention, the balance obtained in the (meth) acrylic acid extraction column 200 to be described later may be recycled to the (meth) acrylic acid absorption tower 100 and used as an absorption solvent. In particular, it is more advantageous in terms of improving process efficiency that the balance is supplied to at least one point corresponding to 10 to 30% from the top of the absorption tower (100). This is described in detail in the description of the (meth) acrylic acid extraction column 200. Meanwhile, the (meth) acrylic acid absorption tower 100 may have an internal pressure of 1 to 1.5 bar or 1 to 1.3 bar, 50 to 100 ° C. or more, in consideration of the water content according to the expansion condition of the (meth) acrylic acid and the saturated steam pressure. It can be operated under an internal temperature of 50 to 80 ° C.
한편, 상기 흡수 공정에서, (메트)아크릴산 흡수탑 (100)의 하부로는 (메트)아크릴산 수용액이 배출되고， 그 상부로는 (메트)아크릴산이 탈기된 비웅축성 가스가 배출된다. 이때, 상기 (메트)아크릴산 수용액에는 농도On the other hand, in the absorption step, the (meth) acrylic acid aqueous solution is discharged to the lower portion of the (meth) acrylic acid absorption tower 100, the (meth) acrylic acid is degassed Non-cumulative gas is emitted. At this time, concentration in the (meth) acrylic acid aqueous solution
40 % 이상, 또는 40 내지 90 중량0 /0， 또는 50 내지 90 중량0 /0의40% or more, or 40 to 90 weight 0/0, or 50 to 90 weight 0/0
(메트)아크릴산이 포함되도록 하는 것이 전체 공정의 효율 측면에서 유리할 수 있다. It may be advantageous in terms of the efficiency of the overall process to include (meth) acrylic acid.
수득된 (메트)아크릴산 수용액은, 도 1과 같이， 수용액 이송 라인 (102)을 통해 (메트)아크릴산 추출 컬럼 (200)으로 공급될 수 있다. 도 1과 같이 (메트)아크릴산 흡수 공정과 증류 공정 사이에 추출 공정을 도입할 경우， 상기 추출 공정에서 (메트)아크릴산 수용액에 포함된 대부분의 흡수 용제를 제거할 수 있어, 증류 공정의 처리 부담을 낮출 수 있고 에너지 사용량을 절감할 수 있다.  The obtained (meth) acrylic acid aqueous solution may be supplied to the (meth) acrylic acid extraction column 200 through the aqueous solution transfer line 102 as shown in FIG. 1. When an extraction process is introduced between the (meth) acrylic acid absorption process and the distillation process as shown in FIG. 1, most of the absorption solvents contained in the (meth) acrylic acid aqueous solution can be removed in the extraction process, thereby reducing the processing burden of the distillation process. It can lower and save energy consumption.
한편 (메트)아크릴산 흡수탑 (100)의 상부로 배출되는 비웅축성 가스 중 적어도 일부는 비웅축성 가스에 포함된 유기 부산물 (특히 초산)을 회수하는 공정으로 공급될 수 있고, 그 나머지는 폐가스 소각로로 공급되어 폐기될 수 있다. 즉， 발명의 일 구현 예에 따르면， 상기 비웅축성 가스를 흡수 용제와 접촉시켜, 상기 비웅축성 가스에 포함된 초산을 회수하는 공정이 수행될 수 있다. 상기 비응축성 가스를 흡수 용제와 접촉시키는 공정은 초산 흡수탑 (150)에서 수행될 수 있다. 비제한적인 예로 초산 흡수탑 (150)의 상부로는 초산을 흡수하기 위한 흡수 용제 (공정수)가 공급되고, 초산 흡수탑 (150)의 하부로는 초산을 함유한 수용액이 배출될 수 있다. 그리고, 상기 초산 함유 수용액은 (메트)아크릴산 흡수탑 (100)의 상부로 공급되어 흡수 용제로써 사용될 수 있다. 또한， 상기 초산이 탈기된 비웅축성 가스는 (메트)아크릴산의 합성반웅 공정으로 순환되어 재사용될 수 있다. 이때, 초산의 효과적인 흡수를 위하여, 초산 흡수탑 (150)은 1 내지 1 .5 bar또는 1 내지 1.3 bar의 내부 압력， 및 50 내지 100 °C 또는 50 내지 80 °C의 내부 온도 하에서 운전될 수 있다. 이 밖에도 초산 흡수탑 (150)의 구체적인 운전 조건은 대한민국 공개특허 제 2009-0041355호에 개시된 내용에 따를 수 있다. Meanwhile, at least some of the non-uniform gas discharged to the upper portion of the (meth) acrylic acid absorption tower 100 may be supplied to a process of recovering organic by-products (particularly acetic acid) included in the non-uniform gas, and the rest of the waste gas incinerator. It can be supplied and discarded. That is, according to the exemplary embodiment of the present invention, the process of recovering acetic acid included in the non-uniform gas may be performed by contacting the non-uniform gas with an absorption solvent. The process of contacting the non-condensable gas with the absorption solvent may be performed in the acetic acid absorption tower 150. As a non-limiting example, an absorption solvent (process water) for absorbing acetic acid may be supplied to the upper portion of the acetic acid absorption tower 150, and an aqueous solution containing acetic acid may be discharged to the lower portion of the acetic acid absorption tower 150. In addition, the acetic acid-containing aqueous solution may be supplied to the upper portion of the (meth) acrylic acid absorption tower 100 to be used as an absorption solvent. In addition, the non-axial gas from which the acetic acid is degassed may be circulated in the synthetic reaction process of (meth) acrylic acid and reused. At this time, for the effective absorption of acetic acid, the acetic acid absorption tower 150 can be operated under an internal pressure of 1 to 1.5 bar or 1 to 1.3 bar, and an internal temperature of 50 to 100 ° C or 50 to 80 ° C. have. In addition, specific operating conditions of the acetic acid absorption tower 150 may be in accordance with the contents disclosed in the Republic of Korea Patent Publication No. 2009-0041355.
(추출공정) Extraction process
한편， (메트)아크릴산 수용액을 추출 컬럼에서 추출 용매와 접촉시켜 (메트)아크릴산 추출액과 그 추잔액을 얻는 추출 공정이 수행된다. 이때, 상기 (메트)아크릴산 수용액은 전술한 흡수 공정을 통해 준비된 것일 수 있다. Meanwhile, an aqueous (meth) acrylic acid solution is contacted with an extraction solvent in an extraction column. An extraction process is performed to obtain the (meth) acrylic acid extract and the balance thereof. In this case, the (meth) acrylic acid aqueous solution may be prepared through the above-described absorption process.
상기 추출 공정은 (메트)아크릴산 추출 컬럼 (200)에서 수행될 수 있다. 상기 추출 컬럼 (200)에 공급된 (메트)아크릴산 수용액은 추출 용매와 접촉하여 상당량의 (메트)아크릴산이 용해된 추출액 (extract solution)과 (메트)아크릴산의 상당량을 잃은 추잔액 (raffinate solution)으로 각각 배출된다. 이때， 상대적으로 가벼운 상인 상기 추출액은 추출 컬럼 (200)의 상부 배출구를 통해 수득되고, 상대적으로 무거운 상인 상기 추잔액은 추출 컬럼의 하부 배출구를 통해 수득된다. 상기 추잔액은， 추출 컬럼 (200)으로부터 배출되기 전에， 추출 컬럼의 하부 정치 구간에 일정 수준의 양이 정치된 상태로 존재하며, 그 중 일부가 추출 컬럼의 하부 배출구로 배출된다.  The extraction process may be performed in the (meth) acrylic acid extraction column 200. The (meth) acrylic acid aqueous solution supplied to the extraction column 200 is an extract solution in which a considerable amount of (meth) acrylic acid is dissolved in contact with an extraction solvent and a considerable amount of (meth) acrylic acid is lost. Each is discharged. At this time, the relatively light phase of the extract is obtained through the upper outlet of the extraction column 200, the relatively heavy phase of the extract is obtained through the bottom outlet of the extraction column. Before the withdrawal from the extraction column 200, the balance liquid is present in a fixed amount in a fixed state in the lower stationary section of the extraction column, some of which is discharged to the lower outlet of the extraction column.
이와 같이， 추출 컬럼 (200)에서 (메트)아크릴산 수용액을 추출 용매와 접촉시키는방법 (즉 증류에 비해 에너지 사용량이 적은 추출)을 통해， 상기 (메트)아크릴산 수용액에 포함된 대부분의 물이 제거될 수 있다. 그에 따라 후속 공정인 증류 공정의 처리 부담을 낮출 수 있어, 전체 공정의 에너지 효율이 향상될 수 있다. 나아가, 증류 공정의 처리 부담을 낮춤으로써, 증류 시 발생할 수 있는 (메트)아크릴산의 중합 반웅이 최소화될 수 있어 , 보다 향상된 (메트)아크릴산의 회수 효율이 확보될 수 있다.  As such, most of the water contained in the aqueous (meth) acrylic acid solution may be removed through a method of contacting the aqueous (meth) acrylic acid solution with the extraction solvent in the extraction column 200 (that is, extraction using less energy than distillation). Can be. Accordingly, the treatment burden of the subsequent process, which is a distillation process, can be reduced, and the energy efficiency of the entire process can be improved. Furthermore, by lowering the processing burden of the distillation process, the polymerization reaction of (meth) acrylic acid that may occur during distillation can be minimized, thereby improving the recovery efficiency of (meth) acrylic acid.
한편， 상기 추출 공정에서 수득된 추잔액은 전술한 흡수 공정에 흡수 용제로써 재순환된다. 특히， 발명의 구현 예에 따르면， 상기 추잔액은 (메트)아크릴산 흡수탑 (100)의 최상부가 아닌 최상부로부터 10 내지 30 %, 또는 최상부로부터 10 내지 25%， 또는 최상부로부터 15 내지 30%, 또는 최상부로부터 10 내지 20 %, 또는 최상부로부터 15 내지 25%에 해당하는 적어도 어느 한 지점으로 공급될 수 있다. 그와 동시에， 상기 추출 컬럼 (200)에 공급되는 (메트)아크릴산 수용액 (즉, 피드)에 대한 추출 용매의 중량비 (S/F)는 0.3 초과 1.0 미만， 또는 0.3 초과 0.8 이하， 또는 0.5 이상 1.0 미만, 또는 0.5 이상 0.8 이하로 조절될 수 있다.  On the other hand, the balance obtained in the extraction process is recycled as an absorption solvent in the above-mentioned absorption process. In particular, according to an embodiment of the invention, the balance is 10 to 30% from the top, or 10 to 25% from the top, or 15 to 30% from the top of the (meth) acrylic acid absorption tower 100, or It may be fed to at least one point corresponding to 10 to 20% from the top, or 15 to 25% from the top. At the same time, the weight ratio (S / F) of the extraction solvent to the aqueous (meth) acrylic acid solution (ie, feed) supplied to the extraction column 200 is greater than 0.3 and less than 1.0, or greater than 0.3 and 0.8 or less, or 0.5 or more and 1.0 Or less than 0.5 or more than 0.8.
이처럼 상기 추출 공정을 통해 수득된 추잔액을 흡수탑 (100)의 특정 지점으로 재순환시킴과 동시에 추출 용매의 중량비 (S/F)를 조절함에 따라， 추출 용매의 사용량과 공정 에너지의 소비량을 대폭으로 낮출 수 있다. 즉， 전술한 공정 조건을 통해, 상기 구현 예의 회수 방법은 보다 적은 양의 추출 용매와 에너지 소비량으로도 상기 흡수 공정과 추출 공정에서의 (메트)아크릴산의 손실을 최소화할 수 있다. 또한 후속되는 증류 공정에서 용매의 리플럭스 (reflux)를 증대시킬 수 있어 (메트)아크릴산의 회수 효율을 더욱 높일 수 있다. As such, the balance obtained through the extraction process is determined in the absorption tower (100). By recycling to the point and controlling the weight ratio (S / F) of the extraction solvent, the amount of the extraction solvent used and the consumption of process energy can be significantly reduced. That is, through the aforementioned process conditions, the recovery method of the embodiment can minimize the loss of (meth) acrylic acid in the absorption process and the extraction process even with a smaller amount of extraction solvent and energy consumption. It is also possible to increase the flux of the solvent (reflux) in the subsequent distillation process to further increase the recovery efficiency of (meth) acrylic acid.
상기 추출 공정에서, 상기 피드에 대한 추출 용매의 증량비 (S/F)가 0.3 이하일 경우, 상기 추출 공정에서 흡수 용제 (물)의 제거 효율이 떨어지게 되고, 장시간 운전이 불가능할 수 있으며， 결과적으로 추출 공정의 도입 효과가 미미해질 수 있다. 그리고, 상기 피드에 대한 추출 용매의 중량비 (S/F)가 1.0 이상일 경우, 에너지 소비량의 감축 효과가 미미해질 수 있다. 특히, 상기 중량비 (S/F)가 높아질수록 추출 효율은 향상될 수 있지만， 후속되는 증류 공정에서서 (메트)아크릴산의 손실이 증가할 수 있으며， 이를 막기 위한 용매의 리플럭스 (reflux)가 과도하게 높아져 바람직하지 않다.  In the extraction process, when the increase ratio (S / F) of the extraction solvent to the feed is 0.3 or less, the removal efficiency of the absorption solvent (water) in the extraction process is lowered, it may not be possible to operate for a long time, and consequently extraction The effect of introducing the process may be negligible. In addition, when the weight ratio (S / F) of the extraction solvent to the feed is 1.0 or more, the effect of reducing the energy consumption may be insignificant. In particular, as the weight ratio (S / F) is increased, the extraction efficiency may be improved, but the loss of (meth) acrylic acid may be increased in a subsequent distillation process, and the flux of solvent to prevent this is excessive. It is not desirable to be high.
한편, (메트)아크릴산 흡수탑 (100)에 대한 상기 추잔액의 공급 지점은 흡수탑 (100)의 종류에 따라 실질적인 흡수가 이루어지는 부분을 고려하여 결정될 수 있다. 예를 들어, 상기 흡수 공정이 층진 컬럼 타입 (packed column type)의 (메트)아크릴산 흡수탑에서 수행되는 경우， 상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점으로 공급될 수 있다. 또한, 상기 흡수 공정이 멀티스테이지 트레이 타입 (multistage tray type)의 (메트)아크릴산 흡수탑에서 수행되는 경우, 상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 단 수 대비 최상단으로부터 10 내지 30 %에 해당하는 적어도 어느 한 단으로 공급될 수 있다.  On the other hand, the supply point of the balance of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the portion where the substantial absorption is made according to the type of the absorption tower (100). For example, when the absorption process is performed in a (meth) acrylic acid absorption tower of a packed column type, the balance obtained through the extraction process is compared with the total packing height of the (meth) acrylic acid absorption tower. It may be supplied to at least one point corresponding to 10 to 30% from the top. In addition, when the absorption process is performed in a (meth) acrylic acid absorption tower of a multistage tray type, the balance obtained through the extraction process is the highest compared to the total number of stages of the (meth) acrylic acid absorption tower. From at least one stage corresponding to 10 to 30% from.
이때， 상기 추잔액이 흡수탑 (100)의 최상부로부터 30 %를 초과하는 지점으로 공급될 경우, 흡수 효율이 떨어질 수 있을 뿐만 아니라， 추출 공정에서 추잔액을 통한 (메트)아크릴산의 손실량이 커지는 등 전체적인 공정 효율이 저하될 수 있다. 그리고, 상기 추잔액이 흡수탑 (100)의 최상부로부터 10 % 미만의 지점으로 공급될 경우, 흡수 효율은 향상될 수 있으나, 상대적으로 상기 추잔액에 포함된 유기 부산물이 흡수탑 (100) 내에서 층분히 회수되지 못할 수 있다. At this time, if the balance is supplied to the point exceeding 30% from the top of the absorption tower 100, not only the absorption efficiency may be lowered, but the amount of loss of (meth) acrylic acid through the balance in the extraction process increases, etc. Overall process efficiency can be reduced. And, the weight balance of the absorption tower (100) When supplied to the point of less than 10% from the top, the absorption efficiency may be improved, but the organic by-products included in the balance can be relatively unable to be recovered in the absorption tower 100.
한편, 상기 추출 컬럼 (200)에 공급되는 추출 용매는 (메트)아크릴산에 대한 가용성과 소수성을 갖는 것일 수 있다. 다만, 후속 공정인 증류 컬럼 (300)에서 요구되는 공비 용매의 물성을 감안하여， 상기 추출 용매는 (메트)아크릴산 보다 낮은 끓는 점을 갖는 것이 바람직하다. 예를 들어， 상기 추출 용매는 120 °C 이하, 또는 10 내지 120 °C , 또는 50 내지 120 °C의 끓는 점을 갖는 소수성 용매일 수 있다. Meanwhile, the extraction solvent supplied to the extraction column 200 may have solubility and hydrophobicity for (meth) acrylic acid. However, in consideration of the physical properties of the azeotropic solvent required in the subsequent distillation column (300), it is preferable that the extraction solvent has a lower boiling point than (meth) acrylic acid. For instance, the extraction solvent may be daily for a hydrophobic having a boiling point of 120 ° C or less, or from 10 to 120 ° C, or from 50 to 120 ° C.
한편, 상기 추출 컬럼 (200)에 공급되는 추출 용매는 (메트)아크릴산에 대한 가용성과 소수성을 갖는 것이 바람직하다. 그리고, 후속 공정인 증류 공정에서 요구되는 용매의 종류와 그 물성을 감안하예 상기 추출 용매는 (메트)아크릴산 보다 낮은 끓는 점을 갖는 것이 바람직하다. 발명의 일 구현 예에 따르면, 상기 추출 용매는 120 °C 이하, 또는 10 내지 120 °C , 또는 50 내지 120 °C의 끓는 점을 갖는 소수성 용매인 것이 공정 운용상 유리할 수 있다. Meanwhile, the extraction solvent supplied to the extraction column 200 preferably has solubility and hydrophobicity for (meth) acrylic acid. In addition, in view of the type and physical properties of the solvent required in the subsequent distillation step, the extraction solvent preferably has a lower boiling point than (meth) acrylic acid. According to one embodiment of the invention, the extraction solvent can be advantageous to operate the process in a hydrophobic solvent having a boiling point of 120 ° C or less, or from 10 to 120 ° C, or from 50 to 120 ° C.
구체적으로, 상기 추출 용매는 벤젠 (benzene), 를루엔 (toluene), 자일렌 (xylene), n-헵탄 (n-heptane), 사이클로헵탄 (cycloheptane), 사이클로헵텐 (cycloheptene), 1 -헵텐 (1-heptene), 에틸 -벤젠 (ethyl-benzene), 메틸-사이클로핵산 (methyl-cyclohexane), n-부틸 아세테이트 (n-butyl acetate), 이소부틸 아세테이트 (isobutyl acetate), 이소부틸 아크릴레이트 (isobutyl acrylate), n-프로필 아세테이트 (π-prapyl acetate), 이소프로필 아세테이트 (isopropyl acetate), 메틸 이소부틸 케톤 (methyl isobutyl ketone), 2-메틸 -1 -헵텐 (2-methyl-1 -heptene), 6-메틸 -1 -헵텐 (6-methyl-1 -heptene), 4-메틸 -1 -헵텐 (4-methyl-1 -heptene), 2-에틸 -1 -헥센 (2-ethyl-1 -hexene), 에틸사이클로펜탄 (ethylcyclopentane), 2-메틸 -1-핵센 (2-methyl-1-hexene), 2，3-디메틸펜탄 (2,3-dimethylpentane), 5-메틸 -1-핵센 (5-methyl-1 -hexene), 및 이소프로필-부틸-에테르 (isoprapyl-butyl-ether)로 이루어진 군에서 선택된 1종 이상의 화합물일 수 있다.  Specifically, the extraction solvent is benzene, toluene, xylene, n-heptane, cycloheptane, cycloheptene, 1-heptene (1) -heptene, ethyl-benzene, methyl-cyclohexane, n-butyl acetate, isobutyl acetate, isobutyl acrylate , n-propyl acetate, isopropyl acetate, methyl isobutyl ketone, 2-methyl-1 -heptene, 6-methyl -1 -heptene (6-methyl-1 -heptene), 4-methyl-1 -heptene (4-methyl-1 -heptene), 2-ethyl-1 -hexene (2-ethyl-1 -hexene), ethylcyclo Pentane (ethylcyclopentane), 2-methyl-1-hexene, 2,3-dimethylpentane (2,3-dimethylpentane), 5-methyl-1-nuxene (5-methyl-1- hexene), and isoprapyl-butyl-ether It may be at least one member selected from the group consisting of compounds.
그리고, 발명의 일 구현 예에 따르면， 상기 추출 컬럼 (200)으로 공급되는 (메트)아크릴산 수용액의 온도는 10 내지 70 °C인 것이 추출 효율의 확보 측면에서 유리하다. And, according to one embodiment of the invention, to the extraction column 200 The temperature of the aqueous (meth) acrylic acid solution to be supplied is advantageously 10 to 70 ° C in terms of ensuring extraction efficiency.
상기 추출 공정에서 추출 컬럼 (200)으로는 액-액 접촉 방식에 따른 통상의 추출 컬럼이 특별한 제한 없이 이용될 수 있다. 비제한적인 예로， 상기 추출 컬럼 (200)은 Karr type의 왕복 플레이트 컬럼 (Karr type reciprocating plate column), 회전-원판형 컬럼 (rotary-disk contactor), Scheibel 컬럼, Kuhni 컬럼, 분무 추출 타워 (spray extraction tower), 충진 추출 타워 (packed extraction tower), 필스 충진 컬럼 (pulsed packed column) 등일 수 있다.  As the extraction column 200 in the extraction process, a conventional extraction column according to the liquid-liquid contacting method may be used without particular limitation. As a non-limiting example, the extraction column 200 may be a Karr type reciprocating plate column, a rotary-disk contactor, a Scheibel column, a Kuhni column, a spray extraction tower. tower, packed extraction tower, pulse packed column, and the like.
이와 같은 추출 공정을 통해, 상기 추출 컬럼 (200)의 상부로는 Through such an extraction process, the upper part of the extraction column 200
(메트)아크릴산 추출액이 배출되고， 배출된 추출액은 이송 라인 (203)을 통해 증류 컬럼 (300)으로 공급된다. 그리고, 상기 추출 컬럼 (200)의 하부로는 추잔액이 배출되고, 배출된 추잔액은 이송 라인 (201 )을 통해 (메트)아크릴산 흡수탑 (100)의 특정 지점으로 재순환된다. The (meth) acrylic acid extract is discharged, and the discharged extract is supplied to the distillation column 300 through the transfer line 203. In addition, the remaining balance is discharged to the lower portion of the extraction column 200, and the discharged balance is recycled to a specific point of the (meth) acrylic acid absorption tower 100 through the transfer line 201.
이때， 상기 추출액에는 목적 화합물인 (메트)아크릴산 이외에, 추출 용매, 물 및 유기 부산물이 포함될 수 있다. 일 구현 예에 따르면， 안정적인 운전이 수행된 정상 상태에서, 상기 추출액에는 (메트)아크릴산 30 내지 60 중량0 /0, 추출 용매 30 내지 60 중량0 /0, 물 3 내지 10 중량0 /0， 및 잔량의 유기 부산물이 포함될 수 있다. 즉, 상기 추출 공정을 통해 (메트)아크릴산 수용액에 포함되어 있는 대부분의 물 (예를 들어 상기 수용액에 포함된 물의 90 중량0 /。 이상)은 추잔액으로 회수될 수 있다. 이처럼 상기 추출 공정에서 대부분의 물이 회수됨에 따라, 증류 공정의 운전 부담을 줄여 에너지 소비량을 낮출 수 있다. 그리고, 이를 통해 증류 조건이 완화될 수 있어， 증류 공정에서 (메트)아크릴산의 중합 반웅이 최소화될 수 있는 등 운전 안정성의 확보와 (메트)아크릴산의 회수 효율 향상이 가능하다. In this case, in addition to (meth) acrylic acid as the target compound, the extract may include an extraction solvent, water, and organic by-products. According to one embodiment, in a steady state and a stable operation is performed, the extract has a (meth) acrylate, 30 to 60 parts by weight 0/0, the extraction solvent 30 to 60 parts by weight 0/0, water, 3 to 10 parts by weight 0/0, and Residual organic byproducts may be included. That is, through the extraction step (meth) acrylic acid contained in the aqueous solution of most of the water (e.g. 90 wt. 0 /. Or more of water contained in the aqueous solution) which may be recovered as a weight balance. In this way, as most of the water is recovered in the extraction process, the operation burden of the distillation process can be reduced to lower the energy consumption. In addition, through this, distillation conditions can be alleviated, such that polymerization reaction of (meth) acrylic acid can be minimized in the distillation process, and thus, it is possible to secure operational stability and improve recovery efficiency of (meth) acrylic acid.
그리고, 상기 추출 컬럼 (200)으로부터 수득되는 추잔액은 대부분 물로 이루어질 수 있으며, 추출되지 못한 (메트)아크릴산이 포함되어 있을 수 있다. 다만, 발명의 일 구현 예에 따르면， 상기 추잔액에는 농도 15 중량 % 이하 또는 3 내지 15 중량0 /。의 (메트)아크릴산이 포함되어 있을 수 있어， 상기 흡수 공정과 추출 공정에서의 (메트)아크릴산의 손실이 최소화될 수 있다. (증류공정) In addition, the balance obtained from the extraction column 200 may be mostly made of water, and may not contain (meth) acrylic acid that is not extracted. However, according to one embodiment of the invention, the weight balance may contain (meth) acrylic acid having a concentration of 15% by weight or less or 3 to 15% by weight 0 /. Loss of acrylic acid can be minimized. Distillation process
한편， 상기 (메트)아크릴산 추출액을 포함하는 피드 (feed)를 증류하여 (메트)아크릴산을 얻는 증류 공정이 수행된다.  Meanwhile, a distillation process of distilling a feed including the (meth) acrylic acid extract to obtain (meth) acrylic acid is performed.
발명의 일 구현 예에 따르면, 상기 피드는 전술한 추출 공정으로부터 공급되는 (메트)아크릴산 추출액일 수 있다. 이 경우, 상기 피드는， 도 1과 같이, (메트)아크릴산 추출액 이송 라인 (203)을 통해 증류 컬럼 (300)으로 공급된다.  According to one embodiment of the invention, the feed may be a (meth) acrylic acid extract supplied from the above-described extraction process. In this case, the feed is supplied to the distillation column 300 through the (meth) acrylic acid extract transfer line 203, as shown in FIG.
전술한 바와 같이， 이전의 (메트)아크릴산 회수 방법은 (메트)아크릴산 흡수탑 (100)에서 수득된 (메트)아크릴산 수용액을 증류 컬럼 (300)에 공급하여 증류하는 방법이 일반적이었다. 그에 비하여， 발명의 일 구현 예에 따른 회수 방법은, 상기 (메트)아크릴산 수용액을 (메트)아크릴산 추출 컬럼 (200)에 공급하여 추출한 후, 이를 통해 물의 함량이 최소화된 추출액을 증류 컬럼 (300)에서 증류하는 방법에 따른다. 그에 따라, 증류 공정에서의 처리 부담을 낮출 수 있다. 또한, 증류 컬럼 (300)에서 상기 추출액 도입부 근처의 은도를 낮게 유지할 수 있어 증류시 (메트)아크릴산의 증합 반웅이 최소화될 수 있는 등 보다 안정적인 연속 공정의 운용이 가능하다. 나아가 증류 공정에 사용되는 에너지 사용량을 현저히 낮출 수'있어, 전체 공정의 에너지 효율이 보다 향상될 수 있다. As described above, the previous (meth) acrylic acid recovery method was a method of distilling the (meth) acrylic acid aqueous solution obtained from the (meth) acrylic acid absorption tower 100 by supplying it to the distillation column 300. In contrast, in the recovery method according to an embodiment of the present invention, the (meth) acrylic acid aqueous solution is supplied to the (meth) acrylic acid extraction column 200 and extracted, and through this the distillation column 300 extracts the minimized water content. Follow the distillation method. Thereby, the processing burden in a distillation process can be reduced. In addition, the degree of silver near the extract introduction portion can be kept low in the distillation column 300, so that the reaction reaction of distillation of (meth) acrylic acid can be minimized. Furthermore, it is possible significantly to lower the energy consumption, as used in the distillation process, it can be improved than the energy efficiency of the overall process.
이때, 효율적인 증류가 이루어질 수 있도록 하기 위하여， 상기 피드가 공급되는 피드 포인트는 증류 컬럼 (300)의 중앙부인 것이 유리하며, 바람직하게는， 증류 컬럼 (300)의 최상단으로부터 전체 단의 40 내지 60%에 해당하는 어느 한 지점일 수 있다.  In this case, in order to enable efficient distillation, the feed point to which the feed is supplied is advantageously the center of the distillation column 300, preferably, 40 to 60% of the entire stage from the top of the distillation column 300 It may be any one point corresponding to.
증류 컬럼 (300)으로 공급된 피드는, 증류 컬럼 (300)의 상부로 도입된 공비 용매와 접촉하게 되고, 적정 은도로 가열되면서 증발과 웅축에 의한 증류가 이루어진다.  The feed supplied to the distillation column 300 is brought into contact with the azeotrope introduced into the top of the distillation column 300, and is evaporated and coaxially distilled while being heated with appropriate silver.
이때 상기 피드에 포함된 (메트)아크릴산을 그 나머지 성분들 (예를 들어, 물, 초산， 추출 용매 등)로부터 효을적으로 분리하기 위하여, 상기 증류는 공비 증류 방식으로 수행되는 것이 바람직하다.  At this time, in order to effectively separate the (meth) acrylic acid contained in the feed from the remaining components (for example, water, acetic acid, extraction solvent, etc.), the distillation is preferably carried out by azeotropic distillation.
상기 공비 증류 방식에 적용되는 용매는 물 및 초산과 공비를 이를 수 있고, (메트)아크릴산과는 공비를 이루지 않는 소수성 공비 용매인 것이 바람직하다. 그리고, 상기 소수성 공비 용매는 (메트)아크릴산 보다 낮은 끓는 점 (예를 들어 120 "C 이하, 또는 10 내지 120 °C , 또는 50 내지 120 °C의 끓는 점)을 갖는 것이 바람직하다. The solvent applied to the azeotropic distillation method is azeotropic with water and acetic acid It is preferable that it is a hydrophobic azeotropic solvent which can be used and does not form an azeotropy with (meth) acrylic acid. And, the hydrophobic azeotropic solvent preferably has a lower boiling point than (meth) acrylic acid (eg 120 " C or lower, or 10-120 ° C., or 50-120 ° C.).
구체적으로， 상기 소수성 공비 용매는 벤젠 (benzene), 를루엔 (toluene), 자일렌 (xylene), π-헵탄 (n-heptane), 사이클로헵탄 (cycloheptane), 시 "이클로헵텐 (cycloheptene), 1 -헵텐 (1 -heptene), 에틸-밴젠 (ethyl-benzene), 메틸-사이클로핵산 (methyl-cyclohexane), n-부틸 아세테이트 (π-butyl acetate), 이소부틸 아세테이트 (isobutyl acetate), 이소부틸 아크릴레이트 (isobutyl acrylate), n-프로필 아세테이트 (n-prcpyl acetate), 이소프로필 아세테이트 (is<3propyl acetate), 메틸 이소부틸 케톤 (methyl isobutyl ketone), 2-메틸 -1 -헵텐 (2-methyl-1 -heptene), 6-메틸 -1 -헵텐 (6-methyl-1 -heptene), Specifically, the hydrophobic azeotropic solvent may be benzene, toluene, xylene, π-heptane, n-heptane, cycloheptane, cy "cycloheptene, 1 1-heptene, ethyl-benzene, methyl-cyclohexane, n-butyl acetate, isobutyl acetate, isobutyl acrylate (isobutyl acrylate), n-prcpyl acetate, isopropyl acetate (is <3propyl acetate), methyl isobutyl ketone, 2-methyl-1 -heptene (2-methyl-1- heptene), 6-methyl-1 -heptene (6-methyl-1 -heptene),
4-메틸 -1 -헵텐 (4-methyM -heptene), 2-에틸 -1 -핵센 (2-ethyM -hexene), 에틸사이클로펜탄 (ethylcyclopentane), 2-메틸 -1 -핵센 (2-methyl-1 -hexene), 2,3-디메틸펜탄(2,3 ^^1^^61 31^), 5-메틸 -1 -핵센 (5-methyl-1 -hexene) 및 이소프로필-부틸-에테르 (isopropyl-butyl-ether)로 이루어진 군에서 선택되는4-methyl-1 -heptene (4-methyM -heptene), 2-ethyl-1 -nuxene (2-ethyM -hexene), ethylcyclopentane, 2-methyl-1 -nuxene (2-methyl-1 -hexene), 2,3-dimethylpentane (2,3 ^^ 1 ^^ 61 31 ^), 5-methyl-1 -nuxene (5-methyl-1 -hexene) and isopropyl-butyl-ether butyl-ether) selected from the group consisting of
1종 이상의 용매일 수 있다. It may be one or more solvents.
그리고， 연속 공정에 따른 생산 효율 등을 감안하여， 상기 소수성 공비 용매는 상기 추출 공정의 추출 용매와 동일한 것이 바람직하다. 이와 같이 추출 공정과 증류 공정에 같은 종류의 용매가 사용될 경우， 증류 컬럼 (300)에서 증류되어 상 분리조 (350)를 통해 회수된 용매의 적어도 일부는 (메트)아크릴산 추출 컬럼 (200)으로 공급되어 추출 용매로 재사용될 수 있다.  And, in view of the production efficiency according to the continuous process, the hydrophobic azeotropic solvent is preferably the same as the extraction solvent of the extraction step. When the same kind of solvent is used in the extraction process and the distillation process as described above, at least a part of the solvent distilled from the distillation column 300 and recovered through the phase separation tank 350 is supplied to the (meth) acrylic acid extraction column 200. And can be reused as extraction solvent.
이와 같은 증류 공정을 통해， 상기 피드 중 (메트)아크릴산을 제외한 나머지 성분들은 공비 용매와 함께 증류 컬럼 (300)의 상부로 배출되고, (메트)아크릴산은 증류 컬럼 (300)의 하부로 배출된다.  Through such a distillation process, the remaining components except for (meth) acrylic acid in the feed are discharged to the top of the distillation column 300 with the azeotropic solvent, and (meth) acrylic acid is discharged to the bottom of the distillation column (300).
이때， 증류 컬럼 (300)의 상부 배출액은 상 분리조 (350)에 공급되어 소정의 처리 후 재사용될 수 있다. 여기서， 상 분리조 (350)는 서로 섞이지 않는 액상을 중력 또는 원심력 등에 의해 분리하는 장치로서， 상대적으로 가벼운 액체 (예를 들어, 유기상)는 상 분리조 (350)의 상부로, 상대적으로 무거운 액체 (예를 들어, 수상)는 상 분리조 (350)의 하부로 회수될 수 있다 일 예로， 증류 컬럼 (300)의 상부 배출액은 상 분리조 (350)에서 공비 용매를 포함하는 유기상과 물을 포함하는 수상으로 분리될 수 있다. 여기서 분리된 유기상은 증류 컬럼 (300)의 상단부로 공급되어 공비 용매로써 사용될 수 있다. 그리고， 필요에 따라 상기 유기상의 적어도 일부는 추출 컬럼 (200)으로 공급되어 추출 용매로써 사용될 수 있다. 그리고 상 분리조 (350)에서 분리된 수상의 적어도 일부는 (메트)아크릴산 흡수탑 (100)으로 공급되어 흡수 용제로써 사용될 수 있고, 일부는 폐수로 처리될 수 있다. 그리고, 상기 수상에는 초산이 일부 포함되어 있을 수 있는데， 상기 수상에 포함된 초산의 농도는 공비 용매의 종류 및 환류비 등에 따라 달라질 수 있다. 비제한적인 예로， 상기 수상에 포함되는 초산의 농도는 1 내지 50 중량0 /。, 또는 2 내지 40 중량0 /。, 또는 3 내지 30 중량0 /0일 수 있다. At this time, the top discharge of the distillation column 300 may be supplied to the phase separation tank 350 to be reused after a predetermined treatment. Here, the phase separation tank 350 is a device for separating liquid phases that are not mixed with each other by gravity or centrifugal force, and the like, and the relatively light liquid (eg, the organic phase) is relatively to the upper portion of the phase separation tank 350. The heavy liquid (eg, the aqueous phase ) may be recovered to the bottom of the phase separation tank 350. For example, the top effluent of the distillation column 300 may include an organic phase including an azeotropic solvent in the phase separation tank 350. It may be separated into an aqueous phase containing water. The separated organic phase can be fed to the top of the distillation column 300 and used as an azeotropic solvent. And, if necessary, at least a part of the organic phase may be supplied to the extraction column 200 and used as an extraction solvent. At least a portion of the aqueous phase separated from the phase separation tank 350 may be supplied to the (meth) acrylic acid absorption tower 100 to be used as an absorption solvent, and some may be treated with wastewater. The acetic acid may be partially contained in the aqueous phase, and the concentration of acetic acid included in the aqueous phase may vary depending on the type of azeotropic solvent and the reflux ratio. Non-limiting examples, the concentration of acetic acid contained in the water phase may be 1 to 50 parts by weight 0 /., Or 2 to 40 parts by weight 0 /., Or 3 to 30 parts by weight 0/0.
한편， 상기 (메트)아크릴산 수용액은 (메트)아크릴산 흡수탑 (100)， 추출 컬럼 (200) 및 증류 컬럼 (300) 등을 거치면서, 상기 수용액에 포함된 (메트)아크릴산의 적어도 일부가 이량체 또는 올리고머를 형성할 수 있다. 이와 같은 (메트)아크릴산의 중합을 최소화하기 위하여, 증류 컬럼 (300)에는 통상적인 중합 방지제가 첨가될 수 있다.  Meanwhile, the aqueous (meth) acrylic acid solution passes through the (meth) acrylic acid absorption tower 100, the extraction column 200, the distillation column 300, and the like, and at least a part of the (meth) acrylic acid included in the aqueous solution is a dimer. Or oligomers. In order to minimize such polymerization of (meth) acrylic acid, a conventional polymerization inhibitor may be added to the distillation column 300.
그리고, 증류 컬럼 (300)의 하부 배출액에는 (메트)아크릴산 이외에 (메트)아크릴산의 중합체와 같은 고비점 부산물, 중합 방지제 둥이 포함되어 있을 수 있다. 따라서, 필요에 따라, 증류 컬럼 (300)의 하부 배출액을 고비점 부산물 분리탑 (400)에 공급하여 상기 하부 배출액에 포함된 고비점 부산물을 분리하는 단계가 추가로 수행될 수 있다. 그리고, 상기 과정을 통해 회수된 크루드 (메트)아크릴산 (CAA)은 추가적인 결정화 공정을 거쳐 보다 높은 순도의 (메트)아크릴산 (HPAA)으로 수득될 수 있다. 이때， 상기 고비점 부산물 분리 공정과 결정화 공정 등은 통상적인 조건 하에서 수행될 수 있으므로, 공정 조건 등은 구체적으로 한정하지 않는다.  In addition, the bottom discharge of the distillation column 300 may include high boiling point by-products such as polymers of (meth) acrylic acid and polymerization inhibitors in addition to (meth) acrylic acid. Therefore, if necessary, a step of separating the high boiling by-products included in the lower discharge by supplying the bottom discharge of the distillation column 300 to the high boiling point by-product separation tower 400 may be performed. In addition, crude (meth) acrylic acid (CAA) recovered through the above process may be obtained as a higher purity (meth) acrylic acid (HPAA) through an additional crystallization process. At this time, the high boiling point by-product separation process and crystallization process, etc. may be performed under conventional conditions, the process conditions and the like are not specifically limited.
한편, 이와 같은 (메트)아크릴산의 회수 방법에세 전술한 각 단계들은 유기적이고 연속적으로 수행될 수 있다. 그리고， 전술한 단계들 이외에 각 단계의 이전 또는 이후 또는 동시에 통상적으로 수행될 수 있는 공정들이 더욱 포함되어 운용될 수 있다. On the other hand, each of the above-described steps in the method for recovering (meth) acrylic acid can be carried out organically and continuously. And, in addition to the above-described steps, processes that can be conventionally performed before, after, or at the same time as each step It can be included and operated more.
발명의 구현 예에 따른 (메트)아크릴산의 회수 방법에서， 전술한 각 공정들은 유기적이고 연속적으로 수행될 수 있다. 그리고, 전술한 공정들 이외에 각 공정의 이전 또는 이후에 통상적으로 수행될 수 있는 공정들이 더욱 수행될 수 있다. 예를 들면， (메트)아크릴산 흡수탑 (100)에서 수득된 (메트)아크릴산 수용액을 (메트)아크릴산 추출 컬럼 (200)으로 공급하기 전에 별도의 탈기탑에 공급하여 저비점 부산물 (아크를레인, 프로피온알데히드, 아세트알데히드, 포름알데히드, 아이소프로필 아세테이트 등)을 제거하는 공정 등이 추가로 수행될 수 있다.  In the method for recovering (meth) acrylic acid according to the embodiment of the present invention, each of the above-mentioned processes may be performed organically and continuously. In addition to the above-described processes, processes that may be conventionally performed before or after each process may be further performed. For example, the (meth) acrylic acid aqueous solution obtained in the (meth) acrylic acid absorption tower 100 is fed to a separate degassing column before feeding to the (meth) acrylic acid extraction column 200 to obtain low boiling point by-products (acrene lane, propion). Aldehyde, acetaldehyde, formaldehyde, isopropyl acetate, etc.) may be further carried out.
'  '
II. (메트)아크릴산의 연속회수장치  II. Continuous recovery device of (meth) acrylic acid
한편， 본 발명의 다른 구현 예에 따르면  Meanwhile, according to another embodiment of the present invention
(메트)아크릴산의 합성반응에 의해 생성된 (메트)아크릴산， 유기 부산물 및 수증기를 포함하는 혼합 가스가 공급되는 흔합 가스 유입구와, 상기 흔합 가스와 물의 접촉에 의해 수득되는 (메트)아크릴산 수용액이 ■ 배출되는 수용액 배출구가 구비된 (메트)아크릴산 흡수탑 (100); (Meth) produced by the synthesis reaction of acrylic acid (meth) heunhap gas inlet through which a mixed gas containing acrylic acid and organic by-products and water vapor is supplied, the heunhap gas and a (meth) acrylic acid aqueous solution obtained by the water contact ■ (Meth) acrylic acid absorption tower 100 having an aqueous solution discharge port discharged;
상기 흡수탑 (100)의 수용액 배출구와 수용액 이송 라인 (102)을 통해 연결된 수용액 유입구， 유입된 (메트)아릴산 수용액과 추출 용매의 접촉에 의해 수득되는 (메트)아크릴산 추출액이 배출되는 추출액 배출구, 및 그 추잔액이 배출되는 추잔액 배출구가 구비된 (메트)아크릴산 추출 컬럼 (200); 및  An aqueous solution inlet connected to the aqueous solution outlet of the absorption tower 100 through an aqueous solution transfer line 102, an extract outlet through which the (meth) acrylic acid extract obtained by contacting the introduced (meth) aryl acid aqueous solution and the extraction solvent is discharged; And a (meth) acrylic acid extraction column (200) provided with a balance liquid discharge port through which the balance liquid is discharged; And
상기 추출 컬럼 (200)의 추출액 배출구와 추출액 이송 라인 (203)을 통해 연결된 추출액 유입구와， 유입된 추출액의 증류에 의해 수득되는 (메트)아크릴산이 배출되는 (메트)아크릴산 배출구가 구비된 증류 컬럼 (300)을 포함하고，  A distillation column having an extract inlet connected to the extract liquid outlet of the extraction column 200 and an extract liquid conveying line 203, and a (meth) acrylic acid outlet through which (meth) acrylic acid obtained by distillation of the extracted extract is discharged ( 300)
상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 최상부로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 지점에 연결되고, The weight balance outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the absorption tower 100 through the weight balance transfer line 201,
상기 추출 컬럼 (200)에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1.0 미만이 되도록 운전되는， (메트)아크릴산의 연속 회수 장치가 제공된다. The weight ratio of the extraction solvent to the (meth) acrylic acid aqueous solution supplied to the extraction column 200 is operated to be greater than 0.3 and less than 1.0, of (meth) acrylic acid A continuous recovery device is provided.
즉, 상기 구현 예의 장치에 있어서, 기본적으로 (메트)아크릴산 흡수탑 (100)은 (메트)아크릴산 수용액 이송 라인 (102)을 통해 (메트)아크릴산 추출 컬럼 (200)과 연결된다. 그리고, (메트)아크릴산 추출 컬럼 (200)은 (메트)아크릴산 추출액 이송 라인 (203)을 통해 증류 컬럼 (300)과 연결된다. 특히， 상기 구현 예의 장치는 (메트)아크릴산 추출 컬럼 (200)에서 수득된 추잔액이 (메트)아크릴산 흡수탑 (100)의 최상부로부터 10 내지 30 。/。에 해당하는 적어도 어느 한 지점으로 공급되도록 연결된 추잔액 이송 라인 (201 )을 포함한다.  That is, in the apparatus of the above embodiment, the (meth) acrylic acid absorption tower 100 is basically connected to the (meth) acrylic acid extraction column 200 through the (meth) acrylic acid aqueous solution transfer line 102. Then, the (meth) acrylic acid extraction column 200 is connected to the distillation column 300 through the (meth) acrylic acid extract liquid transfer line 203. In particular, the apparatus of this embodiment is such that the balance obtained in the (meth) acrylic acid extraction column 200 is supplied to at least one point corresponding to 10 to 30 ° / ° from the top of the (meth) acrylic acid absorption tower 100. Connected balance transfer line 201.
그리고, (메트)아크릴산 흡수탑 (100)의 종류는 상기 흔합 가스 (1 )와 흡수 용제의 접촉 효율 등을 감안하여 결정될 수 있다. 비제한적인 예로, The kind of the (meth) acrylic acid absorption tower 100 may be determined in consideration of the contact efficiency of the mixed gas 1 and the absorption solvent. As a non-limiting example,
(메트)아크릴산 흡수탑 (100)은 층진 컬럼 타입 (packed column type)의 흡수탑, 멀티스테이지 트레이 타입 (multistage tray type)의 흡수탑일 수 있다. 상기 층진 컬럼 타입의 흡수탑은 내부에 래싱 링 (rashing ring), 폴 링 (pall ring), 새들 (saddle)ᅳ 거즈 (gauze), 스트럭쳐 패킹 (structured packing) 등의 층진제가 적용된 것일 수 있다. The (meth) acrylic acid absorption tower 100 may be an absorption tower of a packed column type and an absorption tower of a multistage tray type. The layered column type absorption tower may include a layering agent such as a rashing ring, a pall ring, a saddle gauze, and a structured packing.
여기서, (메트)아크릴산 흡수탑 (100)이 층진 컬럼 타입 (packed column type)의 흡수탑인 경우， 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점에 연결된다.  Here, when the (meth) acrylic acid absorption tower 100 is an absorption tower of a packed column type, the extraction liquid outlet of the extraction column 200 is connected to the absorption tower 100 through the extraction liquid conveying line 201. At least one point corresponding to 10-30% from the top relative to the total packing height.
또한, (메트)아크릴산 흡수탑 (100)이 멀티스테이지 트레이 타입 (multistage tray type)의 흡수탑인 경우, 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 단 수 대비 최상단으로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 단에 연결된다. In addition, when the (meth) acrylic acid absorption tower 100 is a multistage tray type absorption tower, the extraction liquid outlet of the extraction column 200 is connected to the absorption tower (201) through the extraction liquid transport line 201. At least one end corresponding to 10 to 30 0 /.
(메트)아크릴산 추출 컬럼 (200)으로는 액-액 접촉 방식에 따른 통상의 추출 컬럼이 특별한 제한 없이 적용될 수 있다. 비제한적인 예로， 상기 추출 컬럼 (200)은 Karr type의 왕복 플레이트 컬럼 (Karr type reciprocating plate column), 회전-원판형 컬럼 (rotary-disk contactor), Scheibel 컬럼, Kuhni 컬럼， 분무 추출 컬럼 (spray extraction column), 충진 추출 컬럼 (packed extraction tower), 펄스 층진 컬럼 (pulsed packed column) 등일 수 있다. As the (meth) acrylic acid extraction column 200, a conventional extraction column according to the liquid-liquid contacting method may be applied without particular limitation. As a non-limiting example, the extraction column 200 may be a Karr type reciprocating plate column, a rotary-disk contactor, a Scheibel column, a Kuhni column, a spray extraction column. column, packed extraction column extraction towers, pulsed packed columns, and the like.
증류 컬럼 (300)은 내부에 전술한 층전제가 포함된 팩 컬럼 또는 다단 컬럼, 바람직하게는 시브 트레이 컬럼 (Sjeve tray column), 듀얼플로우 트레이 컬럼 (dual flow tray column)이 구비된 것일 수 있다. Distillation column 300 is a packed column or multi-stage column contain a layer premise described above therein, preferably a sieve tray column (S j eve tray column), a dual flow tray column (dual flow tray column) may have been provided with a have.
이 밖에, 초산 흡수탑 (150), (메트)아크릴산 수용액 이송 라인 (102), 추출액 이송 라인 (203)， 상 분리조 (350), 고비점 부산물 분리탑 (400) 등은 본 발명이 속하는 기술분야에서 통상적인 구성을 갖는 것일 수 있다. 이하, 본 발명의 이해를 돕기 위하여 바람직한 실시예를 제시한다. 그러나 하기의 실시예들은 본 발명을 예시하기 위한 것일 뿐， 본 발명을 이들만으로 한정하는 것은 아니다. ■ In addition, acetic acid absorption tower 150, (meth) acrylic acid aqueous solution transfer line 102, extract liquid transfer line 203, phase separation tank 350, high boiling point by-product separation tower 400, etc. It may be one having a conventional configuration in the field. Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are only for illustrating the present invention, and the present invention is not limited thereto. ■
실시예 1  Example 1
도 1과 같은 구성의 장치와 Aspen Plus 공정 시물레이터 (Aspen Technology, Inc.)를 이용하여， 다음과 같은 아크릴산 연속 회수 공정을 수행하였다.  Using the apparatus of FIG. 1 and the Aspen Plus process simulator (Aspen Technology, Inc.), the following acrylic acid continuous recovery process was performed.
(흡수공정)  (Absorption process)
프로필렌의 산화 반웅을 통해 얻어진 흔합 가스를 준비하였다. 상기 흔합 가스의 조성은 아크릴산 약 16.6 중량0 /。, 아크를레인 약 0.3 중량0 /。, 초산 약 0.5 중량0 /。, 미반웅 프로필렌 약 0.3 중량0 /。, 이산화탄소 및 일산화탄소 약 2.6 중량0 /0， 수증기 약 10/1 중량0 /。, 질소 및 산소 약 69.1 중량0 /0， 고비점 부산물 약 0.3 중량0 /。이다. The mixed gas obtained through the reaction reaction of propylene was prepared. The composition of the mixed gas is about 16.6 weight 0 /。 acrylic acid, about 0.3 weight 0 /。 acetic acid, about 0.5 weight 0 /。 acetic acid, about 0.3 weight 0 /。, and about 2.6 weight 0 carbon dioxide and carbon monoxide. 0, the water vapor of about 10/1 by weight 0 /., nitrogen and oxygen of about 69.1 weight 0/0, and high boiling point by-products about 0.3 parts by weight 0 /.
아크릴산 흡수탑 (100)은 이론단수 총 10 단의 트레이 탑으로서， 내부 온도는 50 내지 100 °C로 조절되었다. 상기 흔합 가스는 약 160 °C의 온도ᅳ 약 1.3 bar의 압력， 및 약 62,860 kg/h의 유량으로 흡수탑 (100)의 최하단에 공급되었다. 그리고, 아크릴산의 흡수 용제인 공정수는 흡수탑 (100)의 최상단으로부터 제 2 단 (총 10 단 중 제 2 단)으로 공급되었다. Acrylic acid absorption tower 100 is a tray tower of a total of 10 theoretical stages, the internal temperature was adjusted to 50 to 100 ° C. The mixed gas was supplied to the bottom of the absorption tower 100 at a temperature of about 160 ° C. at a pressure of about 1.3 bar, and a flow rate of about 62,860 kg / h. And the process water which is an absorption solvent of acrylic acid was supplied from the upper end of the absorption tower 100 to the 2nd stage (2nd stage of a total of 10 stages).
그리고, 흡수탑 (100)의 하부로 아크릴산 수용액 (조성: 아크릴산 약 66.1 중량0 /。, 초산 약 4.2 중량0 /。， 및 물 약 28.4 중량0 /0, 기타 약 1 .3 중량0 /。)을 약 15,814 kg/h의 유량으로 얻었다. 상기 아크릴산 수용액은 이송 라인 (102)을 통해 아크릴산 추출 컬럼 (200)으로 공급되었다. (추출공정) Then, the aqueous acrylic acid solution to lower the absorption of the tower 100 (composition: acrylic acid 66.1 weight from about 0 / acetate, about 4.2 parts by weight 0 /, and water from about 28.4 wt. 0/0, and other about 1 .3 wt. 0 /.) Was obtained at a flow rate of about 15,814 kg / h. The aqueous acrylic acid solution was fed to the acrylic acid extraction column 200 via a transfer line 102. Extraction process
아크릴산 추출 컬럼 (200)은 이론단수 총 5 단의 트레이 탑으로서, 최상단으로 상기 아크릴산 수용액이 도입되었다.  Acrylic acid extraction column 200 is a tray tower of a total of five theoretical stages, the acrylic acid aqueous solution was introduced at the top.
그리고, 증류 컬럼 (300)의 상부 배출액에서 유기층으로 수득된 를루엔을 포함하는 환류 흐름의 일부가 추출 컬럼 (200)의 추출 용매로 사용되었다. 이때， 상기 아크릴산 수용액에 대한 추출 용매의 중량비 (S/F)는 약 0.7 이 되도록 조절되었다.  Then, a portion of the reflux stream containing toluene obtained as the organic layer in the top discharge of the distillation column 300 was used as the extraction solvent of the extraction column 200. At this time, the weight ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to about 0.7.
안정적인 운전이 수행된 후 정상 상태에서 추출 컬럼 (200)의 상부로 추출액이 얻어졌으며， 추출 컬럼 (200)의 하부로 추잔액이 얻어졌다. 추출 컬럼 (200)의 정상 상태 운전에서의 각 흐름의 유량과 농도를 하기 표 1에 나타내었다.  After the stable operation was performed, the extraction liquid was obtained at the top of the extraction column 200 in a steady state, and the extraction liquid was obtained at the bottom of the extraction column 200. The flow rate and concentration of each flow in steady state operation of the extraction column 200 are shown in Table 1 below.
【표 1】  Table 1
Figure imgf000022_0001
Figure imgf000022_0001
상기 표 1을 통해 알 수 있는 바와 같이， 상기 추잔액에 포함된 아크릴산의 함량은 약 5.9 중량0 /0이고, 상기 추출액에 포함된 를루엔의 함량은 약 47.3 중량 0/。인 것으로 확인되었다. 그리고 추출 컬럼 (200)에서의 물 제거율은 약 71.8%로 측정되었다. As can be seen from the Table 1, the content of the acrylic acid contained in the weight balance is about 5.9 wt. 0/0, the content of the toluene that contains the extract was found to be about 47.3 weight 0 /. And the water removal rate in the extraction column 200 was measured to be about 71.8%.
상기 추출액은 이송 라인 (203)을 통해 증류 컬럼 (300)으로 공급되었다. 그리고， 상기 추잔액은 이송 라인 (201 )을 통해 흡수탑 (100)의 최상단으로부터 제 2 단 (총 10 단 중 제 2 단)에 약 3000 kg/h의 유량으로 공급되어 흡수 용제로 재사용되었다. 이때 흡수탑 (100)에서 탑 상부로 유출되어 손실되는 아크릴산의 양은 135.9 kg/h로 나타났다.  The extract was fed to distillation column 300 via transfer line 203. Then, the balance was supplied to the second stage (second stage of the total 10 stages) from the top of the absorption tower 100 through the transfer line 201 at a flow rate of about 3000 kg / h and reused as the absorption solvent. At this time, the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 135.9 kg / h.
(증류공정)  Distillation process
증류 컬럼 (300)은 이론단수 총 20 단의 트레이 탑으로서， 운전 압력은 약 1 10 torr로 유지되었다.  The distillation column 300 is a tray tower having a total of 20 theoretical stages, and the operating pressure was maintained at about 1 10 torr.
상기 추출액은 증류 컬럼 (300)의 최상단으로부터 제 9 단의 위치에 약 23,227 kg/h의 유량으로 도입되었다. 그리고, 상 분리조 (350)에서 분리된 를루엔 환류 흐름의 일부가 증류 컬럼 (300)의 최상단인 제 1 단에 도입되었다. 또한， 증류 컬럼 (300)의 상단으로는 를루엔， 추출액에 포함되어 있던 물 및 초산이 배출되었고, 하단으로는 아크릴산이 배출되었다. The extract is about at the position of the ninth stage from the top of the distillation column (300) Introduced at a flow rate of 23,227 kg / h. A portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300. In addition, toluene, water and acetic acid contained in the extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
이때, 상기 추출 공정 없이 흡수 -증류 공정만으로 수행되는 경우에서 증류 컬럼으로 공급되는 총 를루엔 흐름과 동일하게 운전될 수 있도록 하기 위하여 (즉， 증류 컬럼에 공급되는 를루엔의 총량을 동일하게 하기 위하여), 상기 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름이 약 16,578 kg/h로 조절되었다.  In this case, in the case where only the absorption-distillation process is performed without the extraction process, in order to operate the same as the total toluene flow fed to the distillation column (that is, to equalize the total amount of toluene supplied to the distillation column). ), The toluene reflux flow to the distillation column 300 was adjusted to about 16,578 kg / h.
그리고， 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 In addition, the concentration of acrylic acid included in the organic layer in the phase separation tank 350 is about
0.9 중량0 /。, 수층에 포함된 아크릴산의 농도는 약 0.8 중량 0/。로 확인되었다. 0.9 weight 0 /., The concentration of acrylic acid contained in the aqueous layer was found to be about 0.8 weight 0 /.
: 리고， 증류 컬럼 (300)에서 소비되는 에너지는 약 3.8 Gcal/h 였다. 참고로, 상기 추출 공정 없이 흡수 -증류 공정만으로 수행되는 경우에서, 상기 증류 공정에 소비되는 에너지는 약 5.8 Gcal/h 이다. 이와 비교하여, 실시예 1의 방법에 따를 경우 증류 컬럼 (300)에서의 에너지 절감율은 약 34.5 %이다.  In addition, the energy consumed in the distillation column 300 was about 3.8 Gcal / h. For reference, in the case where only the absorption-distillation process is performed without the extraction process, the energy consumed in the distillation process is about 5.8 Gcal / h. In comparison, the energy saving rate in the distillation column 300 according to the method of Example 1 is about 34.5%.
그리고 상기와 같은 연속 공정을 통해， 흡수탑 (100)으로 공급된 약 And through the continuous process as described above, the drug supplied to the absorption tower 100
10,723 kg/h의 아크릴산 증 약 10,116 kg/h의 아크릴산이 증류 컬럼 (300)의 하부로 회수되었고， 아크릴산의 원패스 회수율은 약 94.3 0/。로 나타났다. 여기서, 상기 "원패스 회수율 "은 각 단위 공정에서 발생하는 아크릴산의 손실이 다시 회수되지 않았을 때의 회수율을 의미한다. 실시예 2 10,723 kg / h of acrylic acid increase Approximately 10,116 kg / h of acrylic acid was recovered to the bottom of the distillation column 300, and the one-pass recovery of acrylic acid was found to be about 94.3 0 /. Here, the "one pass recovery rate" means a recovery rate when the loss of acrylic acid generated in each unit process is not recovered again. Example 2
실시예 1과 동일한 방법으로 흡수 공정과 추출 공정이 수행되었다. 다만， 증류 공정에서， 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름 중 를루엔의 함량이 실시예 1 보다 과량이 되도톡 조절되었고， 를루엔 환류 흐름은 약 25,000 kg/h로 나타났다.  The absorption and extraction processes were performed in the same manner as in Example 1. However, in the distillation process, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was adjusted to an excess amount than that of Example 1, and the toluene reflux flow was about 25,000 kg / h.
그리고, 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 0.6 중량0 /。， 수층에 포함된 아크릴산의 농도는 약 0.6 중량 0/。로 확인되었다. 그리고, 증류 컬럼 (300)에서 소비되는 에너지는 약 4.7 Gcal/h 로서， 추출 공정을 포함하지 않는 방법에 비하여 약 19.0 0/。의 에너지 절감율을 나타내었다. In addition, in the phase separation tank 350, the concentration of acrylic acid included in the organic layer was about 0.6 weight 0 /. The concentration of acrylic acid included in the aqueous layer was about 0.6 weight 0 /. And, the energy consumed in the distillation column 300 is about 4.7 Gcal / h, Compared with the method without an extraction process, the energy saving rate was about 19.0 0 /.
상기와 같은 연속 공정을 통해， 흡수탑 (100)으로 공급된 약 10,723 kg/h의 아크릴산 중 약 10,167 kg/h의 아크릴산이 증류 컬럼 (300)의 하부로 회수되었고, 아크릴산의 원패스 회수율은 약 94.8 %로 나타났다. 실시예 3  Through such a continuous process, about 10,167 kg / h of acrylic acid of about 10,723 kg / h of acrylic acid supplied to the absorption tower 100 was recovered to the bottom of the distillation column 300, and the one-pass recovery rate of acrylic acid was about 94.8%. Example 3
실시예 1과 동일한 방법으로 흡수 공정과 추출 공정이 수행되었다. 다만, 증류 공정에서, 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름 중 를루엔의 함량이 실시예 1 보다 소량이 되도록 조절되었고 를루엔 환류 흐름은 약 1으 000 kg/h로 나타났다.  The absorption and extraction processes were performed in the same manner as in Example 1. In the distillation process, however, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was controlled to be smaller than that of Example 1, and the toluene reflux flow was about 1,000 kg / h.
그리고, 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 1.0 중량 %， 수층에 포함된 아크릴산의 농도는 약 1.0 중량0 /0로 확인되었다. 그리고, 증류 컬럼 (300)에서 소비되는 에너지는 약 3.1 Gcal/h 로서, 추출 공정을 포함하지 않는 방법에 비하여 약 46.6 0/。의 에너지 절감율을 나타내었다. Then, the phase separation concentration of the acrylic acid contained in the organic layer in the tank 350 is the concentration of the acrylic acid contained in about 1.0 wt%, the aqueous layer was confirmed to be about 1.0 wt. 0/0. In addition, the energy consumed in the distillation column 300 is about 3.1 Gcal / h, which shows an energy saving rate of about 46.6 0 /.
상기와 같은 연속 공정을 통해， 흡수탑 (100)으로 공급된 약 10,723 kg/h의 아크릴산 중 약 10,098 kg/h의 아크릴산이 증류 컬럼 (300)의 하부로 회수되었고， 아크릴산의 원패스 회수율은 약 94.2 %로 나타났다. 비교예 1  Through such a continuous process, about 10,098 kg / h of acrylic acid of about 10,723 kg / h of acrylic acid supplied to the absorption tower 100 was recovered to the bottom of the distillation column 300, and the one-pass recovery rate of acrylic acid was about 94.2%. Comparative Example 1
실시예 1과 동일한 방법으로 흡수 공정이 수행되었다.  The absorption process was performed in the same manner as in Example 1.
다만, 추출 공정에서， 아크릴산 수용액에 대한 추출 용매의 중량비 (S/F)는 약 0.3 이 되도록 조절되었다. 그리고， 추출 컬럼 (200)의 정상 상태 운전에서의 각 흐름의 유량과 농도를 하기 표 2에 나타내었다. In the extraction process, however, the weight ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to be about 0.3. And, the flow rate and concentration of each flow in the steady state operation of the extraction column 200 is shown in Table 2 below.
【표 2] [Table 2]
추출 용매 아크릴산 수용액 ᄀ — 1 추잔액 Extraction Solvent Acrylic Acid Solution a — 1 Balance
Mass Flow (kg/h) 6,000 15,814 18,707 3,107 Mass Flow (kg / h) 6,000 15,814 18,707 3,107
트후에 99.3 0 31 .8 0.1 아크릴산 0.4 66.1 54.3 10.4 조성  Hue 99.3 0 31 .8 0.1 Acrylic acid 0.4 66.1 54.3 10.4 Composition
초산 0.3 4.2 3.0 3.9 (wt%) □  Acetic acid 0.3 4.2 3.0 3.9 (wt%) □
0 28.4 10.1 83.7 기타 0 1.3 0.8 1 .9 비교예 1의 경우 추출 컬럼 (200)에서의 물 제거 효율 (제거율 약 58.0%)이 실시예 1 (제거율 약 71.8%)에 비해 떨어져 장시간 운전이 블가능하였다. 그리고, 비교예 1의 경우 상기 추잔액에 포함된 아크릴산의 함량이 약 10.4 중량 0/。로 높아 아크릴산의 손실량이 실시예 1에 비해 큰 것으로 나타났다. 비교예 2 0 28.4 10.1 83.7 Others 0 1.3 0.8 1 .9 In the case of Comparative Example 1, the water removal efficiency (removal rate of about 58.0%) in the extraction column 200 was lower than that of Example 1 (removal rate of about 71.8%), thereby enabling a long time operation. In the case of Comparative Example 1, the amount of acrylic acid contained in the weight balance was about 10.4 weight 0 / °, indicating that the loss of acrylic acid was greater than that of Example 1. Comparative Example 2
(흡수공정)  (Absorption process)
아크릴산의 흡수 용제인 공정수와 추출 공정으로부터 얻어진 추잔액을 흡수탑 (100)의 최상단으로 공급한 것을 제외하고, 실시예 1과 동일한 방법으로 흡수 공정이 수행되었다.  The absorption process was carried out in the same manner as in Example 1, except that the water obtained as the absorption solvent of acrylic acid and the weight balance obtained from the extraction process were supplied to the top of the absorption tower 100.
(추출공정)  Extraction process
아크릴산 수용액에 대한 추출 용매의 중량비 (S/F)가 약 2 가 되도록 조절한 것을 제외하고， 실시예 1과 동일한 방법으로 추출 공정이 수행되었다. 추출 컬럼 (200)의 정상 상태 운전에서의 각 흐름의 유량과 농도를 하기 표 The extraction process was performed in the same manner as in Example 1, except that the weight ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to about 2. The flow rate and concentration of each stream in the steady state operation of the extraction column 200 are shown in the following table.
3에 나타내었다. 3 is shown.
【표 3】  Table 3
Figure imgf000025_0001
Figure imgf000025_0001
비교예 2의 경우 추출 컬럼 (200)에서의 물 제거 효율 (제거율 약 85.5%)이 실시예 1에 비해 우수하였고, 상기 추잔액에 포함된 아크릴산의 함량도 약 1 .6 중량 0/。로 낮아 아크릴산의 손실량이 실시예 1에 비해 적은 것으로 나타났다. For Comparative Example 2, the water removal efficiency (removal rate of about 85.5%) in the extraction column 200 was superior to that of Example 1, and the content of acrylic acid included in the balance was also lowered to about 1.6 weight 0 /. The loss of acrylic acid was found to be less than in Example 1.
상기 추출액은 이송 라인 (203)을 통해 증류 컬럼 (300)으로 공급되었다. 그리고 상기 추잔액은 이송 라인 (201 )을 통해 흡수탑 (100)의 최상단에 3000 kg/h의 유량으로 공급되어 흡수 용제로 재사용되었다. 이때 흡수탑 (100)에서 탑 상부로 유출되어 손실되는 아크릴산의 양은 73.0 kg/h로 나타났다. (증류공정) The extract was fed to distillation column 300 via transfer line 203. The balance was supplied to the top of the absorption tower 100 through a transfer line 201 at a flow rate of 3000 kg / h and reused as an absorption solvent. At this time, the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 73.0 kg / h. Distillation process
상기 추출액은 실시예 1과 동일한 증류 컬럼 (300)의 최상단으로부터 거 I 9 단의 위치에 43,294 kg/h의 유량으로 도입되었다. 그리고, 상 분리조 (350)에서 분리된 틀루엔 환류 흐름의 일부가 증류 컬럼 (300)의 최상단인 제 1 단에 도입되었다. 또한, 증류 컬럼 (300)의 상단으로는 틀루엔 : 추출액에 포함되어 있던 물 및 초산이 배출되었고， 하단으로는 아크릴산이 배출되었다. The extract was introduced at a flow rate of 43,294 kg / h from the top of the same distillation column 300 as in Example 1 to the location of the near I 9 stage. A portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300. In addition, water and acetic acid contained in the toluene : extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
이때, 상기 추출 공정 없이 흡수 -증류 공정만으로 수행되는 경우에서 증류 컬럼으로 공급되는 총 를루엔 흐름과 동일하게 운전될 수 있도록 하기 위하여 (즉, 증류 컬럼에 공급되는 를루엔의 총량을 동일하게 하기 위하여), 상기 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름이 약 7,158 kg/h로 조절되었다.  In this case, in the case where only the absorption-distillation process is performed without the extraction process, in order to operate the same as the total toluene flow fed to the distillation column (that is, to equalize the total amount of toluene supplied to the distillation column). ), The toluene reflux flow to the distillation column 300 was adjusted to about 7,158 kg / h.
그리고， 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 3.1 중량0 /。， 수층에 포함된 아크릴산의 농도는 약 3.0 중량0 /。로 확인되었다. 이는 실시예 1에서 상 분리조 (350)로 손실되는 아크릴산의 농도보다 높은 것이다. 그에 따라， 비교예 2의 경우 아크릴산의 손실을 막기 위해 를투엔 환류.흐름이 과량으로 필요하였다. And, in the phase separation tank 350, the concentration of acrylic acid in the organic layer was about 3.1 weight 0 /. The concentration of acrylic acid in the water layer was about 3.0 weight 0 /. This is higher than the concentration of acrylic acid lost to the phase separation bath 350 in Example 1. Accordingly, in the case of Comparative Example 2, toluene reflux flow was necessary in order to prevent the loss of acrylic acid.
그리고, 증류 컬럼 (300)에서 소비되는 에너지는 약 4.7 Gcal/h로서, 상기 추출 공정 없이 흡수 -증류 공정만으로 수행되는 경우에 비하여 약 19.0 %의 에너지 절감을을 나타내었다.  In addition, the energy consumed in the distillation column 300 is about 4.7 Gcal / h, which represents an energy saving of about 19.0% compared to the case where only the absorption-distillation process is performed without the extraction process.
상기와 같은 연속 공정을 통해， 흡수탑 (100)으로 공급된 약 10,723 kg/h의 아크릴산 중 약 9,263 kg/h의 아크릴산이 증류 컬럼 (300)의 하부로 회수되었고, 아크릴산의 원패스 회수율은 약 86.4 %로 나타났다.  Through such a continuous process, about 9,263 kg / h of acrylic acid was recovered to the bottom of the distillation column 300 of about 10,723 kg / h of acrylic acid supplied to the absorption tower 100, and the one-pass recovery rate of acrylic acid was about 86.4%.
요컨데, 비교예 2의 경우 실시예 1에 비하여 추출 효율은 우수하였으나, 증류 컬럼에서 아크릴산의 손실이 증가하였다. 그에 따라， 비교예 2의 경우 아크릴산의 손실을 막기 위한 틀루엔 환류 흐름이 과량으로 필요하였고, 증류 공정에서의 에너지 소비량은 높게 나타났다. 또한, 비교예 2의 경우 실시예 1에 비하여 에너지 소비량 대비 아크릴산의 회수율이 떨어지는 것으로 나타났다. 비교예 3 In short, in Comparative Example 2, extraction efficiency was better than that of Example 1, but the loss of acrylic acid in the distillation column was increased. Accordingly, in the case of Comparative Example 2, an excess of toluene reflux flow was required to prevent the loss of acrylic acid, and the energy consumption in the distillation process was high. In addition, in the case of Comparative Example 2, the recovery rate of acrylic acid was lower than the energy consumption compared to Example 1. Comparative Example 3
아크릴산의 흡수 용제인 공정수와 추출 공정으로부터 얻어진 추잔액을 흡수탑 (100)의 최상단으로 공급한 것을 제외하고, 실시예 1과 동일한 방법으로 흡수 공정이 수행되었다. 그리고， 추출 공정과 증류 공정은 실시예 1과 동일한 방법으로 수행되었다.  The absorption process was carried out in the same manner as in Example 1, except that the water obtained as the absorption solvent of acrylic acid and the weight balance obtained from the extraction process were supplied to the top of the absorption tower 100. The extraction process and the distillation process were performed in the same manner as in Example 1.
상기 추출 공정에서 흡수탑 (100)으로 공급되는 추잔액이 흡수탑 (100)의 최상단에 3000 kg/h의 유량으로 공급되어 흡수 용제로 재사용되도록 하였다.  The extraction liquid supplied to the absorption tower 100 in the extraction process was supplied to the top of the absorption tower 100 at a flow rate of 3000 kg / h to be reused as the absorption solvent.
이때 흡수탑 (100)에서 탑 상부로 유출되어 손실되는 아크릴산의 양은 151 .0 kg/h로 나타났다. 이러한 아크릴산의 손실량은 비교예 1과 비교하더라도 약 10 % 가량 증가한 것이다. 비교예 4  At this time, the amount of acrylic acid flowing out of the absorption tower 100 to the top of the tower was found to be 151 .0 kg / h. The loss of such acrylic acid is increased by about 10% even when compared to Comparative Example 1. Comparative Example 4
실시예 1과 동일한 방법으로 흡수 공정이 수행되었다 (추출 공정의 추잔액을 흡수탑의 제 2 단에 공급).  The absorption process was carried out in the same manner as in Example 1 (the balance of the extraction process was supplied to the second stage of the absorption tower).
(추출공정)  Extraction process
아크릴산 수용액에 대한 추출 용매의 증량비 (S/F)가 약 1 이 되도록 조절한 것을 제외하고, 실시예 1과 동일한 방법으로 추출 공정이 수행되었다. 추출 컬럼 (200)의 정상 상태 운전에서의 각 흐름의 유량과 농도를 하기 표 4에 나타내었다.  The extraction process was carried out in the same manner as in Example 1, except that the increase ratio (S / F) of the extraction solvent to the aqueous acrylic acid solution was adjusted to about 1. The flow rates and concentrations of the flows in the steady state operation of the extraction column 200 are shown in Table 4 below.
【표 4】  Table 4
Figure imgf000027_0001
Figure imgf000027_0001
비교예 4의 경우 추출 컬럼 (200)에서의 물 제거 효율 (제거율 약 77.4%)이 실시예 1 (제거율 약 71 .8%)에 비해 우수하였고， 상기 추잔액에 포함된 아크릴산의 함량도 실시예 1에 비해 낮은 것으로 나타났다.  In Comparative Example 4, the water removal efficiency (removal rate of about 77.4%) in the extraction column 200 was superior to that of Example 1 (removal rate of about 71 .8%), and the content of acrylic acid included in the balance was also used in Example. It was found to be lower than 1.
상기 추출액은 이송 라인 (203)을 통해 증류 컬럼 (300)으로 공급되었다. 그리고, 상기 추잔액은 이송 라인 (201 )을 통해 흡수탑 (100)의 제 2 단에 3000 kg/h의 유량으로 공급되어 흡수 용제로 재사용되었다. 이때 흡수탑 (100)에서 탑 상부로 유출되어 손실되는 아크릴산의 양은 95.5 kg/h로 나타났다. The extract was fed to distillation column 300 via transfer line 203. In addition, the balance was supplied to the second stage of the absorption tower 100 through a transfer line 201 at a flow rate of 3000 kg / h and reused as an absorption solvent. At this time, the amount of acrylic acid lost to the top of the tower in the absorption tower 100 was found to be 95.5 kg / h.
(증류공정)  Distillation process
상기 추출액은 실시예 1과 동일한 증류 컬럼 (300)의 최상단으로부터 제 9 단의 위치에 27,848 kg/h의 유량으로 도입되었다. 그리고, 상 분리조 (350)에서 분리된 를루엔 환류 흐름의 일부가 증류 컬럼 (300)의 최상단인 제 1 단에 도입되었다. 또한, 증류 컬럼 (300)의 상단으로는 를루엔, 추출액에 포함되어 있던 물 및 초산이 배출되었고， 하단으로는 아크릴산이 배출되었다.  The extract was introduced at a flow rate of 27,848 kg / h from the top of the same distillation column 300 as in Example 1 to the position of the ninth stage. A portion of the toluene reflux stream separated in the phase separation tank 350 was then introduced into the first stage, which is the top of the distillation column 300. In addition, toluene, water and acetic acid contained in the extract were discharged to the top of the distillation column 300, and acrylic acid was discharged to the bottom.
이때, 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름은, 실시예 2와 동일한 환류비 (환류비 약 1.9)가 되도록 하기 위하여， 약 29,000 kg/h로 조절되었다.  At this time, the toluene reflux stream supplied to the distillation column 300 was adjusted to about 29,000 kg / h in order to have the same reflux ratio (reflux ratio about 1.9) as in Example 2.
그리고， 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 In addition, the concentration of acrylic acid included in the organic layer in the phase separation tank 350 is about
0.7 중량0 /。, 수층에 포함된 아크릴산의 농도는 약 0.7 중량0 /。로 확인되었다. 이는 실시예 2에서 상 분리조 (350)로 손실되는 아크릴산의 농도보다 약간 높은 것이다. 0.7 weight 0 /. The concentration of acrylic acid in the aqueous layer was found to be about 0.7 weight 0 /. This is slightly higher than the concentration of acrylic acid lost to the phase separation bath 350 in Example 2.
그리고 증류 컬럼 (300)에서 소비되는 에너지는 약 5.3 Gcal/h로서, 상기 추출 공정 없이' 흡수 -증류 공정만으로 수행되는 경우에 비하여 약 8.6 %의 에너지 절감율을 나타내었다. And the energy consumed in the distillation column 300 is about 5.3 Gcal / h, showing an energy saving rate of about 8.6% compared to the case where only ' absorption-distillation process is performed without the extraction process.
상기와 같은 연속 공정을 통해， 흡수탑 (100)으로 공급된 약 10,723 kg/h의 아크릴산 중 약 10,224 kg/h의 아크릴산이 증류 컬럼 (300)의 하부로 회수되었고， 아크릴산의 원패스 회수율은 약 95.3 %로 나타났다.  Through such a continuous process, about 10,224 kg / h of acrylic acid of about 10,723 kg / h of acrylic acid supplied to the absorption tower 100 was recovered to the lower portion of the distillation column 300, and the one-pass recovery rate of acrylic acid was about 95.3%.
요컨데， 비교예 4의 경우 실시예 2에 비하여 추출 효율은 우수하였으나， 실시예 2와 동일한 환류비에도 불구하고 증류 컬럼에서 아크릴산의 손실이 증가하였다. 또한, 비교예 4의 경우 실시예 2에 비하여 증류 공정에서의 에너지 소비량이 높게 나타났다. 그리고， 비교예 4의 경우 추출 공정을 포함하는 않는 방법에 비하여 약 8.6%의 에너지 절감율을 나타내에 추출 공정의 도입에 따른 효과가 미미한 것으로 확인되었다. 비교예 5 In other words, in Comparative Example 4, extraction efficiency was better than that of Example 2, but the loss of acrylic acid in the distillation column was increased despite the same reflux ratio as in Example 2. In addition, in the case of Comparative Example 4, the energy consumption in the distillation step was higher than in Example 2. In addition, in Comparative Example 4, the energy saving rate of about 8.6% was shown compared to the method not including the extraction process, and the effect of introducing the extraction process was found to be insignificant. Comparative Example 5
아크릴산의 흡수 용제인 공정수와 추출 공정으로부터 얻어진 추잔액을 흡수탑 (100)의 최상단으로 공급한 것을 제외하고， 비교예 4와 동일한 방법으로 흡수 공정이 수행되었다. 그리고 추출 공정과 증류 공정은 비교예 4와 동일한 방법으로 수행되었다.  The absorption process was performed by the same method as the comparative example 4 except having supplied the process water which is the absorption solvent of acrylic acid, and the extraction liquid obtained from the extraction process to the upper end of the absorption tower 100. And the extraction process and distillation process was carried out in the same manner as in Comparative Example 4.
상기 추출 공정에서 흡수탑 (100)으로 공급되는 추잔액이 흡수탑 (100)의 최상단에 3000 kg/h의 유량으로 공급되어 흡수 용제로 재사용되도록 하였다. 이때 흡수탑 (100)에서 탑 상부로 유출되어 손실되는 아크릴산의 양은 88.8 kg/h로 나타났다. 이러한 아크릴산의 손실량은 비교예 4에 비해 약 7 % 가량 감소한 것이다.  The extraction liquid supplied to the absorption tower 100 in the extraction process was supplied to the top of the absorption tower 100 at a flow rate of 3000 kg / h to be reused as the absorption solvent. At this time, the amount of acrylic acid lost to the top of the absorption tower 100 is lost to 88.8 kg / h. This loss of acrylic acid is about 7% reduced compared to Comparative Example 4.
하지만, 비교예 4와 마찬가지로， 비교예 5의 경우 실시예 2와 동일한 환류비에도 불구하고 증류 컬럼에서 아크릴산의 손실이 증가하였다. 또한， 비교예 5의 경우 실시예 2에 비하여 증류 공정에서의 에너지 소비량이 높게 나타났다. 그리고, 비교예 5의 경우 추출 공정을 포함하는 않는 방법에 비하여 약 8.6%의 에너지 절감율을 나타내어, 추출 공정의 도입에 따른 효과가 미미한 것으로 확인되었다. 비교예 6  However, as in Comparative Example 4, in the case of Comparative Example 5, the loss of acrylic acid in the distillation column was increased despite the same reflux ratio as in Example 2. In addition, in the case of Comparative Example 5, the energy consumption in the distillation step was higher than in Example 2. In the case of Comparative Example 5, an energy saving rate of about 8.6% was shown compared to the method not including the extraction process, and the effect of introducing the extraction process was found to be insignificant. Comparative Example 6
비교예 2와 동일한 방법으로 흡수 공정과 추출 공정이 수행되었다. 다만， 증류 공정에서 아크릴산의 손실량을 낮추기 위해， 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름 중 틀루엔의 함량이 비교예 2 보다 과량이 되도록 조절되었고， 를루엔 환류 흐름은 약 15,000 kg/h로 나타났다.  An absorption process and an extraction process were performed in the same manner as in Comparative Example 2. However, in order to lower the loss of acrylic acid in the distillation process, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was controlled to be greater than that of Comparative Example 2, and the toluene reflux stream was about 15,000 kg / h. Appeared.
그에 따라， 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 1 .9 중량0 /。, 수층에 포함된 아크릴산의 농도는 약 1 .8 중량0 /。로, 비교예 2에 비하여 낮아졌고， 아크릴산의 원패스 회수율은 90.1 0/。로 다소 상승하였다. Accordingly, the concentration of acrylic acid included in the organic layer in the phase separation tank 350 was about 1.9 weight 0 /. The concentration of acrylic acid included in the aqueous layer was about 1.8 weight 0 /. It was lowered and the one-pass recovery rate of acrylic acid rose slightly to 90.1 0 /.
그러나, 증류 컬럼 (300)에서 소비되는 에너지는 약 5.5 Gcal/h 로서， 추출 공정을 포함하지 않는 방법에 비하여 약 5.2 %의 에너지 절감율올 나타내어, 추출 컬럼의 도입에 따른 효과가 미미한 것으로 확인되었다. 비교예 7 However, the energy consumed in the distillation column 300 is about 5.5 Gcal / h, an energy saving rate of about 5.2% compared to the method without an extraction process. The effect of introducing the extraction column was found to be insignificant. Comparative Example 7
비교예 2와 동일한 방법으로 흡수 공정과 추출 공정이 수행되었다. 다만, 증류 공정에서 아크릴산의 손실량을 더욱 낮추기 위해, 증류 컬럼 (300)으로 공급되는 를루엔 환류 흐름 중 를루엔의 함량이 비교예 2 보다 과량이 되도록 조절되었고, 를루엔 환류 흐름은 약 25,000 kg/h로 나타났다.  An absorption process and an extraction process were performed in the same manner as in Comparative Example 2. However, in order to further lower the loss of acrylic acid in the distillation process, the content of toluene in the toluene reflux stream supplied to the distillation column 300 was adjusted to be greater than that of Comparative Example 2, and the toluene reflux stream was about 25,000 kg / h.
그에 따라, 상 분리조 (350)에서 유기층에 포함된 아크릴산의 농도는 약 1.3 중량0 /0， 수층에 포함된 아크릴산의 농도는 약 1.2 중량0 /。로, 비교예 2에 비하여 낮아졌고, 아크릴산의 원패스 회수율은 약 93.2 。/。로 다소 상승하였다. Thus, the concentration of the acrylic acid contained in the organic layer in a separating tank (350) is the concentration of the acrylic acid contained in about 1.3 wt. 0/0, the aqueous layer has been reduced as compared to about 1.2 wt. 0 /., Comparative Example 2, acrylic acid The one-pass recovery rate of RH was slightly increased to 93.2 ° / °.
그러나, 증류 컬럼 (300)에서 소비되는 에너지는 약 6.5 Gcal/h 로서, 추출 공정을 포함하지 않는 방법에 비하여 오히려 더 많은 에너지가 소비되는 것으로 확인되었다.  However, the energy consumed in the distillation column 300 is about 6.5 Gcal / h, indicating that more energy is consumed compared to the method that does not include an extraction process.

Claims

【특허청구범위】 [Patent Claims]
【청구항 1】  [Claim 1]
(메트)아크릴산의 합성반웅에 의해 생성된 (메트)아크릴산, 유기 부산물 및 수증기를 포함하는 흔합 가스를 (메트)아크릴산 흡수탑에서 물과 접촉시켜 (메트)아크릴산 수용액을 얻는 흡수 공정 ;  An absorption step of obtaining a (meth) acrylic acid aqueous solution by bringing a mixed gas containing (meth) acrylic acid, organic by-products and water vapor generated by the synthesis reaction of (meth) acrylic acid into water in a (meth) acrylic acid absorption tower;
상기 흡수 공정을 통해 수득된 (메트)아크릴산 수용액을 추출 컬럼에서 추출 용매와 접촉시켜 (메트)아크릴산 추출액과 추잔액을 얻는 추출 공정; 및  An extraction step of bringing the (meth) acrylic acid aqueous solution obtained through the absorption step into contact with an extraction solvent in an extraction column to obtain a (meth) acrylic acid extract and a balance solution; And
상기 추출 공정을 통해 수득된 (메트)아크릴산 추출액을 포함하는 피드 (feed)를 증류하여 (메트)아크릴산을 얻는 증류 공정을 포함하고，  A distillation process of distilling a feed including a (meth) acrylic acid extract obtained through the extraction process to obtain (meth) acrylic acid,
상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 최상부로부터 10 내지 30%에 해당하는 적어도 어느 한 지점으로 공급되고,  The extraction liquid obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the (meth) acrylic acid absorption tower,
상기 추출 컬럼에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1.0 미만인, (메트)아크릴산의 연속.회수 방법.  A method for continuous recovery of (meth) acrylic acid, wherein the weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column is greater than 0.3 and less than 1.0.
【청구항 2】 [Claim 2]
제 1 항에 있어서，  The method of claim 1,
상기 흡수 공정은 충진 컬럼 타입 (packed column type)의 (메트)아크릴산 흡수탑에서 수행되고,  The absorption process is carried out in a packed column type (meth) acrylic acid absorption tower,
상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 %에 해당하는 적어도 어느 한 지점으로 공급되는, (메트)아크릴산의 연속 회수 방법.  The extraction liquid obtained through the extraction process is supplied to at least one point corresponding to 10 to 30% from the top of the total packing height of the (meth) acrylic acid absorption tower, continuous recovery method of (meth) acrylic acid.
【청구항 3】 [Claim 3]
제 1 항에 있어서,  The method of claim 1,
상기 흡수 공정은 멀티스테이지 트레이 타입 (multistage tray type)의 The absorption process is of a multistage tray type
(메트)아크릴산 흡수탑에서 수행되고， Carried out in a (meth) acrylic acid absorption tower,
상기 추출 공정을 통해 수득된 추잔액은 상기 (메트)아크릴산 흡수탑의 전체 단 수 대비 최상단으로부터 10 내지 30 %에 해당하는 적어도 어느 한 단으로 공급되는, (메트)아크릴산의 연속 회수 방법. The balance obtained through the extraction process may be at least 10 to 30% from the top of the total number of stages of the (meth) acrylic acid absorption tower. A continuous recovery method of (meth) acrylic acid supplied to either stage.
【청구항 4】 [Claim 4]
거 1 1 항에 있어서,  According to claim 1 1,
상기 추출 용매는 10 내지 120 °C의 끓는 점을 갖는 소수성 The extraction solvent is hydrophobic with a boiling point of 10 to 120 ° C.
(메트)아크릴산의 연속 회수 방법. Continuous recovery method of (meth) acrylic acid.
【청구항 5】 [Claim 5]
제 1 항에 있어서,  The method of claim 1,
상기 추출 용매는 벤젠 (benzene), 를루엔 (toluene), 자일렌 (xylene), n-헵탄 (n-heptane), 사이클로헵탄 (cycloheptane), 사이클로헵텐 (cycloheptene), The extraction solvent is benzene, toluene, xylene, n-heptane, cycloheptane, cycloheptene, cycloheptene,
1 -헵텐 (1-heptene), 에틸 -벤젠 (ethyl-benzene), 메틸 _사이클로핵산 (methyl-cyclohexane), n-부틸 아세테이트 (n-butyl acetate), 이소부틸 아세테이트 (isobutyl acetate), 이소부틸 아크릴레이트 (isobutyl acrylate), π-프로필 아세테이트 (n-propyl acetate), 이소프로필 아세테이트 (isopropyl acetate), 메틸 이소부틸 케톤 (methyl isobutyl ketone),1-heptene, ethyl-benzene, methyl-cyclohexane, n-butyl acetate, isobutyl acetate, isobutyl acryl Isobutyl acrylate, π-propyl acetate, isopropyl acetate, methyl isobutyl ketone,
2-메틸 -1 -헵텐 ( -methyl-1 -heptene), 6-메틸 -1 -헵텐 (6-methyl-1 -heptene), 4-메틸 -1 -헵텐 (4-methyM -heptene), 2-에틸 -1 -핵센 (2-ethyl-1 -hexene), 에틸사이클로펜탄 (ethylcyclopentane), 2-메틸 -1-핵센 (2-methyl-1-hexene), 2,3-디메틸펜탄 (2,3-dimethylpentane), 5-메틸 -1-헥센 (5-methyl-1 -hexene) 및 이소프로필-부틸-에테르 (isopropyl-butyl-ether)로 이루어진 군에서 선택되는 1종 이상의 화합물인 (메트)아크릴산의 연속 회수 방법. 2-methyl-1 -heptene (-methyl-1 -heptene), 6-methyl-1 -heptene (6-methyl-1 -heptene), 4-methyl-1 -heptene (4-methyM -heptene), 2- 2-ethyl-1-hexene, ethylcyclopentane, 2-methyl-1-hexene, 2,3-dimethylpentane dimethylpentane), 5-methyl-1-hexene and isopropyl-butyl-ether is a series of (meth) acrylic acids which are at least one compound selected from the group consisting of Recovery method.
【청구항 6】 [Claim 6]
제 1 항에 있어서，  The method of claim 1,
상기 추출 공정을 통해 수득된 추출액은 30 내지 60 중량%의 (메트)아크릴산, 30 내지 60 중량 0/。의 추출 용매， 3 내지 10 중량0 /。의 물, 및 잔량의 유기 부산물을 포함하는， (메트)아크릴산의 연속 회수 방법. The extract obtained through the extraction process comprises 30 to 60% by weight of (meth) acrylic acid, 30 to 60% by weight 0 /. Extraction solvent, 3 to 10% by weight 0 /. Water, and the remaining amount of organic by-product, Continuous recovery method of (meth) acrylic acid.
【청구항 7】 제 1 항에 있어서， [Claim 7] The method of claim 1,
상기 추출 공정을 통해 수득된 추잔액은 (메트)아크릴산을 15 증량0 /。 이하로 포함하는， (메트)아크릴산의 연속 회수 방법. The extraction liquid obtained through the extraction process comprises (meth) acrylic acid in an amount of 15 increase 0 /. Or less, continuous recovery method of (meth) acrylic acid.
【청구항 8】 [Claim 8]
제 1 항에 있어서,  The method of claim 1,
상기 (메트)아크릴산의 합성반응은 프로판， 프로필렌, 부탄ᅳ 아이소부틸렌， 및 (메트)아크를레인으로 이루어진 군에서 선택된 1종 이상의 화합물을 기상 촉매 하에서 산화 반응시키는 것인, (메트)아크릴산의 연속 회수 방법.  The synthesis reaction of (meth) acrylic acid is that of (meth) acrylic acid to oxidize at least one compound selected from the group consisting of propane, propylene, butanesium isobutylene, and (meth) acrelane under a gas phase catalyst Continuous recovery method.
【청구항 9】 [Claim 9]
(메트)아크릴산의 합성반응에 의해 생성된 (메트)아크릴산， 유기 부산물 및 수증기를 포함하는 흔합 가스가 공급되는 흔합 가스 유입구와, 상기 흔합 가스와 물의 접촉에 의해 수득되는 (메트)아크릴산 수용액이 배출되는 수용액 배출구가 구비된 (메트)아크릴산 흡수탑 (100);  A mixed gas inlet supplied with a mixed gas containing (meth) acrylic acid, organic by-products and water vapor produced by the synthesis reaction of (meth) acrylic acid, and an aqueous (meth) acrylic acid solution obtained by contacting the mixed gas with water is discharged. (Meth) acrylic acid absorption tower 100 is provided with an aqueous solution outlet;
상기 흡수탑 (100)의 수용액 배출구와 수용액 이송 라인 (102)을 통해 연결된 수용액 유입구， 유입된 (메트)아릴산 수용액과 추출 용매의 접촉에 의해 수득되는 (메트)아크릴산 추출액이 배출되는 추출액 배출구, 및 그 추잔액이 배출되는 추잔액 배출구가 구비된 (메트)아크릴산 추출 컬럼 (200); 상기 추출 컬럼 (200)의 추출액 배출구와 추출액 이송 라인 (203)을 통해 연결된 추출액 유입구와, 유입된 추출액의 증류에 의해 수득되는 (메트)아크릴산이 배출되는 (메트)아크릴산 배출구가 구비된 증류 컬럼 (300)을 포함하고，  An aqueous solution inlet connected to the aqueous solution outlet of the absorption tower 100 through an aqueous solution transfer line 102, an extract outlet through which the (meth) acrylic acid extract obtained by contacting the introduced (meth) aryl acid aqueous solution and the extraction solvent is discharged; And a (meth) acrylic acid extraction column (200) provided with a balance liquid discharge port through which the balance liquid is discharged; A distillation column provided with an extract inlet of the extraction column 200 and an extract inlet connected through an extract transfer line 203, and a (meth) acrylic acid outlet through which (meth) acrylic acid obtained by distillation of the extracted extract is discharged ( 300)
상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 최상부로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 지점에 연결되고， ， The weight balance outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the absorption tower 100 through the weight balance transfer line 201,
상기 추출 컬럼 (200)에 공급되는 (메트)아크릴산 수용액에 대한 추출 용매의 중량비는 0.3 초과 1 .0 미만이 되도록 운전되는, (메트)아크릴산의 연속 회수 장치. The weight ratio of the extraction solvent to the aqueous solution of (meth) acrylic acid supplied to the extraction column 200 is operated to be greater than 0.3 and less than 1.0, that of (meth) acrylic acid Continuous recovery device.
【청구항 10] [Claim 10]
제 9 항에 있어서，  The method of claim 9,
상기 (메트)아크릴산 흡수탑 (100)은 층진 컬럼 타입 (packed column type)의 흡수탑이고,  The (meth) acrylic acid absorption tower 100 is an absorption tower of a packed column type,
상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 팩킹 높이 대비 최상부로부터 10 내지 30 0/。에 해당하는 적어도 어느 한 지점에 연결된， (메.트)아크릴산의 연속 회수 장치. The extraction liquid outlet of the extraction column 200 is connected to at least one point corresponding to 10 to 30 0 /. From the top of the total packing height of the absorption tower through the extraction liquid conveying line 201, ( Meth) acrylic continuous recovery device.
【청구항 1 1】 [Claim 1 11]
제 9 항에 있어서,  The method of claim 9,
상기 (메트)아크릴산 흡수탑 (100)은 멀티스테이지 트레이 타입 (multistage tray type)의 흡수탑이고,  The (meth) acrylic acid absorption tower 100 is an absorption tower of a multistage tray type,
상기 추출 컬럼 (200)의 추잔액 배출구는 추잔액 이송 라인 (201 )을 통해 상기 흡수탑 (100)의 전체 단 수 대비 최상단으로부터 10 내지 30 %에 해당하는 적어도 어느 한 단에 연결된, (메트)아크릴산의 연속 회수 장치.  The extraction liquid outlet of the extraction column 200 is connected to at least one end corresponding to 10 to 30% from the top of the total stage of the absorption tower 100 through the extraction liquid conveying line 201, (meth) Continuous recovery device of acrylic acid.
PCT/KR2014/006608 2013-07-22 2014-07-21 Method and apparatus for continuously recovering (meth)acrylic acid WO2015012551A1 (en)

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