JPH03181440A - Purification of acrylic acid by distillation - Google Patents
Purification of acrylic acid by distillationInfo
- Publication number
- JPH03181440A JPH03181440A JP31976289A JP31976289A JPH03181440A JP H03181440 A JPH03181440 A JP H03181440A JP 31976289 A JP31976289 A JP 31976289A JP 31976289 A JP31976289 A JP 31976289A JP H03181440 A JPH03181440 A JP H03181440A
- Authority
- JP
- Japan
- Prior art keywords
- acrylic acid
- column
- water
- supplied
- distilled
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 title claims abstract description 43
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 238000004821 distillation Methods 0.000 title claims abstract description 16
- 238000000746 purification Methods 0.000 title description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 57
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000011084 recovery Methods 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 17
- 239000007864 aqueous solution Substances 0.000 claims abstract description 11
- 230000018044 dehydration Effects 0.000 claims abstract description 11
- 238000006297 dehydration reaction Methods 0.000 claims abstract description 11
- 239000002904 solvent Substances 0.000 claims description 17
- 239000000243 solution Substances 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 abstract description 8
- 238000005265 energy consumption Methods 0.000 abstract description 7
- 239000002253 acid Substances 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 12
- 239000007788 liquid Substances 0.000 description 7
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 4
- 238000010992 reflux Methods 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 239000008346 aqueous phase Substances 0.000 description 3
- SZNYYWIUQFZLLT-UHFFFAOYSA-N 2-methyl-1-(2-methylpropoxy)propane Chemical compound CC(C)COCC(C)C SZNYYWIUQFZLLT-UHFFFAOYSA-N 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 2
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 description 2
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- MGNZXYYWBUKAII-UHFFFAOYSA-N cyclohexa-1,3-diene Chemical compound C1CC=CC=C1 MGNZXYYWBUKAII-UHFFFAOYSA-N 0.000 description 2
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000019253 formic acid Nutrition 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- UAEPNZWRGJTJPN-UHFFFAOYSA-N methylcyclohexane Chemical compound CC1CCCCC1 UAEPNZWRGJTJPN-UHFFFAOYSA-N 0.000 description 2
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- 238000010533 azeotropic distillation Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- GYNNXHKOJHMOHS-UHFFFAOYSA-N methyl-cycloheptane Natural products CC1CCCCCC1 GYNNXHKOJHMOHS-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000008400 supply water Substances 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はアクリル酸の蒸留精製方法に関し、詳しくはエ
ネルギー消費を低減させたアクリル酸の蒸留精製方法に
関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a distillation purification method for acrylic acid, and more particularly to a distillation purification method for acrylic acid that reduces energy consumption.
〔従来の技術および発明が解決しようとする課題〕プロ
ピレンまたはアクロレインを酸化して得られるアクリル
酸反応生成物は、アクリル酸の他に水、酢酸の他、微量
不純物を含んでいる。このアクリル酸反応生成物からア
クリル酸を分離する方法として、抽剤を用いてアクリル
酸を抽出する方法が行なわれてきたが、設備が大規模で
ある上、消費エネルギーも多大であった。そこで、共沸
剤を用いて共沸蒸留により水を分離する方法が数多く提
案されている（特開昭６０−３８３４１号公報、同６０
−３８３４２号公報、特公昭４９２１１２４号公報、同
５０−２５４５１号公報。[Prior Art and Problems to be Solved by the Invention] Acrylic acid reaction products obtained by oxidizing propylene or acrolein contain water, acetic acid, and trace impurities in addition to acrylic acid. As a method of separating acrylic acid from the acrylic acid reaction product, a method of extracting acrylic acid using an extractant has been used, but this method requires large-scale equipment and consumes a large amount of energy. Therefore, many methods have been proposed for separating water by azeotropic distillation using an azeotropic agent (JP-A-60-38341, JP-A-60-38341;
-38342, Japanese Patent Publication No. 4921124, Japanese Patent Publication No. 50-25451.
同５５−６６２３号公報、同６３−１０６９１号公報な
ど）、シかしながら、これらいずれの方法においても消
費エネルギーは満足しうる程度には低減されていない。However, energy consumption is not reduced to a satisfactory extent in any of these methods.
そこで、本発明者らは共沸剤を用いて蒸留法によりアク
リル酸を精製するにあたり、エネルギー消費の少ない方
法について鋭意研究した結果、溶剤回収塔に水を供給し
て蒸留すればよいことを見出し、本発明を完成した。Therefore, the inventors of the present invention conducted intensive research into a method that consumes less energy when purifying acrylic acid by distillation using an azeotropic agent, and as a result, they discovered that it is sufficient to supply water to a solvent recovery column for distillation. , completed the invention.
すなわち、本発明はアクリル酸と酢酸を含有する粗アク
リル酸水溶液を共沸剤の存在下に蒸留精製する方法にお
いて、
（ａ）該粗アクリル酸水溶液と該共沸剤とを脱水塔に供
給して蒸留し、該粗アクリル酸水溶液中の実質的にすべ
ての水並びに酢酸の一部を塔頂成分として留出するとと
もに残余の酢酸を含有するアクリル酸を塔底成分として
留出し、
０）次いで、該塔底留出液を溶剤回収塔に供給するとと
もに水を該溶剤回収塔に供給して蒸留し、塔頂成分とし
て該塔底留出液中の実質的にすべての酢酸および共沸剤
並びに供給したすべての水を留出し、塔底成分として精
製アクリル酸を回収することを特徴とする粗アクリル酸
水溶液の蒸留精製方法を提供するものである。That is, the present invention provides a method for purifying a crude acrylic acid aqueous solution containing acrylic acid and acetic acid by distillation in the presence of an entrainer, which comprises: (a) supplying the crude aqueous acrylic acid solution and the entrainer to a dehydration tower; 0) Then, substantially all of the water and a portion of the acetic acid in the crude aqueous acrylic acid solution are distilled out as a top component, and the acrylic acid containing the remaining acetic acid is distilled out as a bottom component; , the bottom distillate is supplied to a solvent recovery column and water is supplied to the solvent recovery column for distillation, and substantially all of the acetic acid and entrainer in the bottom distillate are removed as a top component. The present invention also provides a method for distilling and purifying a crude acrylic acid aqueous solution, which is characterized by distilling off all of the supplied water and recovering purified acrylic acid as a column bottom component.
本発明で用いる共沸剤は水に溶けにくく、かつアクリル
酸とは共沸せずに水および酢酸と共沸するものであれば
よく、具体的にはトルエン、ヘプタン、メチルシクロヘ
キサン、シクロヘキサン。The entraining agent used in the present invention may be one that is not easily soluble in water and does not azeotrope with acrylic acid but azeotropes with water and acetic acid, and specifically includes toluene, heptane, methylcyclohexane, and cyclohexane.
エチルベンゼン、イソブチルエーテル、シクロヘキセン
、シクロヘキサジエン等が挙げられる。Examples include ethylbenzene, isobutyl ether, cyclohexene, and cyclohexadiene.
本発明のアクリル酸の蒸留精製方法について以下に説明
する。The distillation purification method of acrylic acid of the present invention will be explained below.
精製しようと思うアクリル酸、酢酸等を含む粗アクリル
酸水溶液を、共沸剤と共に脱水塔に供給して蒸留を行な
う。ここで、一部の酢酸、すべての水や蟻酸等の微量不
純物が塔頂から排出される。A crude aqueous solution of acrylic acid containing acrylic acid, acetic acid, etc. to be purified is supplied to a dehydration tower together with an entrainer for distillation. Here, some acetic acid, all water, and trace impurities such as formic acid are discharged from the top of the column.
なお、脱水塔における蒸留は通常、塔内圧力１００〜３
００ ｍｍＨｇ＊ 塔頂温度４５〜６０°Ｃ５塔底温度
１００″Ｃ以下、還流比（Ｒ／Ｄ）３〜ｉｏの条件で行
なわれる。Note that distillation in a dehydration tower is usually carried out at an internal pressure of 100 to 3
00 mmHg* Column top temperature: 45 to 60°C; bottom temperature: 100″C or less; reflux ratio (R/D): 3 to io.
残余のアクリル酸、酢酸等を含む水溶液は、次いで溶剤
（共沸剤）回収塔に供給される。この際に本発明では水
を供給することを特徴とする。これにより、溶剤回収塔
において水と共沸剤が共に沸し、アクリル酸の分離を容
易にするため、従来型のものよりも溶剤回収塔における
エネルギー消費量を低減することができる。水の注入量
は、共沸剤の循環量に対し５〜２０−ｔ％である。水の
注入量が５ｗｔ％より少ないと、溶剤回収塔におけるエ
ネルギー消費量減少の効果が小さく、２０ｗｔ％を超え
ると、水中にアクリル酸が溶けてしまい好ましくない。The remaining aqueous solution containing acrylic acid, acetic acid, etc. is then supplied to a solvent (azeotropic agent) recovery column. At this time, the present invention is characterized in that water is supplied. As a result, the water and the entrainer boil together in the solvent recovery tower, making it easier to separate the acrylic acid, so that the energy consumption in the solvent recovery tower can be reduced compared to the conventional type. The amount of water injected is 5 to 20-t% relative to the circulating amount of entrainer. If the amount of water injected is less than 5 wt%, the effect of reducing energy consumption in the solvent recovery tower is small, and if it exceeds 20 wt%, acrylic acid will dissolve in the water, which is not preferable.
なお、ここで供給する水としては系外のものを使用して
もよいが、好適には前記脱水塔で留出した水の一部を用
いる。溶剤回収塔における蒸留は通常、塔内圧力５０〜
２００ｎｍＨｇ、塔頂温度４５〜６０℃、塔底温度１０
０℃以下、還流比（Ｒ／Ｄ）１０〜２０の条件で行なわ
れる。Although the water supplied here may be from outside the system, it is preferable to use a portion of the water distilled from the dehydration tower. Distillation in a solvent recovery column is usually carried out at an internal pressure of 50~
200nmHg, tower top temperature 45-60℃, tower bottom temperature 10
It is carried out under the conditions of 0° C. or lower and a reflux ratio (R/D) of 10 to 20.
溶剤回収塔において脱水塔からの残余の水溶液を水と共
に蒸留することにより、塔底から精製されたアクリル酸
を得ることができる。By distilling the remaining aqueous solution from the dehydration tower together with water in the solvent recovery tower, purified acrylic acid can be obtained from the bottom of the tower.
次に、本発明を実施例により説明するが、本発明はこれ
に限定されることはない。Next, the present invention will be explained by examples, but the present invention is not limited thereto.
実施例
アクリル酸４５．５％、酢酸３．２％、ギ酸０．４％お
よび若干のホルムアルデヒドを含む粗アクリル酸水溶液
を５９．４ ｇ／ｈｒで、共沸剤としてトルエンを１４
ｇ／ｈｒで段数３０段の脱水塔に供給し、塔頂圧力２０
０ ＋＋ｍＨｇ、塔頂温度５３℃、塔り温度９１”Ｃ，
還流比５．３の条件で蒸留を行なった。Example: A crude aqueous solution of acrylic acid containing 45.5% acrylic acid, 3.2% acetic acid, 0.4% formic acid and some formaldehyde was fed at a rate of 59.4 g/hr, and toluene was added as an entrainer at 14 g/hr.
g/hr to a dehydration tower with 30 plates, and the top pressure was 20
0 ++ mHg, tower top temperature 53°C, tower temperature 91”C,
Distillation was performed at a reflux ratio of 5.3.
塔頂液より分離された１ ４８ ｇ／ｈｒのトルエンは
水相を分離し全て還流した。また、塔底より得られた脱
水液は、段数６０段の溶剤回収塔に供給した。The aqueous phase of 148 g/hr of toluene separated from the top liquid was refluxed. Further, the dehydrated liquid obtained from the bottom of the column was supplied to a solvent recovery column having 60 plates.
この時、塔頂液より分離した水相を２８．３ ｇ／ｈｒ
のうち１．０ ｇ／ｈｒの割合で溶剤回収塔に供給し、
蒸留を行なった。この水相は５．４ ｗｔ％の酢酸と９
３．１ｗｔ％の水を含有していた。溶剤回収塔における
蒸留は塔頂圧力８０ｍｍＨｇ、塔頂温度４８°Ｃ２塔底
温度９４°Ｃ８還流比１４．９の条件で行なった。At this time, the aqueous phase separated from the top liquid was heated at 28.3 g/hr.
of which is supplied to the solvent recovery tower at a rate of 1.0 g/hr,
Distillation was performed. This aqueous phase contains 5.4 wt% acetic acid and 9
It contained 3.1 wt% water. Distillation in the solvent recovery column was carried out under the conditions of a top pressure of 80 mmHg, a top temperature of 48°C, a bottom temperature of 94°C, and a reflux ratio of 14.9.
塔頂液より分離したトルエンは、再び共沸剤として脱水
塔に供給した。塔底液からは、約９８．９％の回収率で
純度９９．７ｗｔ％のアクリル酸が得られた。また、塔
底液はシースヒーターで加熱したが、加熱量（シースヒ
ーターの消費電力量）は１０１Ｗｈｒ／ｈｒであった。Toluene separated from the top liquid was again supplied to the dehydration tower as an entrainer. Acrylic acid with a purity of 99.7 wt% was obtained from the bottom liquid with a recovery rate of about 98.9%. Further, the bottom liquid was heated with a sheath heater, and the heating amount (power consumption of the sheath heater) was 101 Whr/hr.
比較例
実施例において、溶剤回収塔に水を供給しなかったこと
以外は実施例と同様の操作を行なった。Comparative Example The same operation as in Example was carried out except that water was not supplied to the solvent recovery tower.
塔底液の加熱量は１０３ Ｗｈｒ／ｈｒであった。The amount of heating of the bottom liquid was 103 Whr/hr.
本発明によれば、溶剤回収塔におけるエネルギー消費を
低減させてアクリル酸を精製することが可能である。According to the present invention, it is possible to purify acrylic acid while reducing energy consumption in the solvent recovery tower.
Claims (2)
を共沸剤の存在下に蒸留精製する方法において、 （ａ）該粗アクリル酸水溶液と該共沸剤とを脱水塔に供
給して蒸留し、該粗アクリル酸水溶液中の実質的にすべ
ての水並びに酢酸の一部を塔頂成分として留出するとと
もに残余の酢酸を含有するアクリル酸を塔底成分として
留出し、 （ｂ）次いで、該塔底留出液を溶剤回収塔に供給すると
ともに水を該溶剤回収塔に供給して蒸留し、塔頂成分と
して該塔底留出液中の実質的にすべての酢酸および共沸
剤並びに供給したすべての水を留出し、塔底成分として
精製アクリル酸を回収することを特徴とする粗アクリル
酸水溶液の蒸留精製方法。(1) In a method of purifying a crude acrylic acid aqueous solution containing acrylic acid and acetic acid by distillation in the presence of an entrainer, (a) the crude aqueous acrylic acid solution and the entrainer are supplied to a dehydration tower and distilled. (b) then, substantially all of the water and a portion of the acetic acid in the crude acrylic acid aqueous solution are distilled off as a top component, and the acrylic acid containing the remaining acetic acid is distilled off as a bottom component; The bottom distillate is fed to a solvent recovery column, and water is also fed to the solvent recovery column to be distilled, and substantially all of the acetic acid, entrainer, and entrainer in the bottom distillate are distilled as top components. A method for distilling and purifying a crude acrylic acid aqueous solution, characterized by distilling off all of the supplied water and recovering purified acrylic acid as a column bottom component.
留出する水の一部であることを特徴とする請求項１記載
の粗アクリル酸の蒸留精製方法。(2) The method for distilling and purifying crude acrylic acid according to claim 1, wherein the water supplied to the solvent recovery column is a part of the water distilled off as a top component of the dehydration column.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31976289A JPH03181440A (en) | 1989-12-08 | 1989-12-08 | Purification of acrylic acid by distillation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31976289A JPH03181440A (en) | 1989-12-08 | 1989-12-08 | Purification of acrylic acid by distillation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03181440A true JPH03181440A (en) | 1991-08-07 |
Family
ID=18113899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31976289A Pending JPH03181440A (en) | 1989-12-08 | 1989-12-08 | Purification of acrylic acid by distillation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03181440A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0695736A1 (en) | 1994-08-04 | 1996-02-07 | Mitsubishi Chemical Corporation | Purification of acrylic acid by areotropic distillation |
| US6179966B1 (en) | 1997-11-17 | 2001-01-30 | Sumitomo Chemical Company, Ltd. | Method for producing acrylic acid |
| WO2011010035A1 (en) | 2009-07-22 | 2011-01-27 | Arkema France | Method for producing bioresourced acrylic acid from glycerol |
| JP2012501299A (en) * | 2008-07-22 | 2012-01-19 | アルケマ フランス | Method for producing bio-propionic acid from glycerol |
| US8748545B2 (en) | 2008-09-16 | 2014-06-10 | Arkema France | Process for producing bio-resourced polymer-grade acrylic acid from glycerol |
-
1989
- 1989-12-08 JP JP31976289A patent/JPH03181440A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0695736A1 (en) | 1994-08-04 | 1996-02-07 | Mitsubishi Chemical Corporation | Purification of acrylic acid by areotropic distillation |
| US6179966B1 (en) | 1997-11-17 | 2001-01-30 | Sumitomo Chemical Company, Ltd. | Method for producing acrylic acid |
| JP2012501299A (en) * | 2008-07-22 | 2012-01-19 | アルケマ フランス | Method for producing bio-propionic acid from glycerol |
| US8440859B2 (en) | 2008-07-22 | 2013-05-14 | Arkema France | Method for producing bioresourced propionic acid from glycerol |
| US9206110B2 (en) | 2008-07-22 | 2015-12-08 | Arkema France | Method for producing bioresourced propionic acid from glycerol |
| US8748545B2 (en) | 2008-09-16 | 2014-06-10 | Arkema France | Process for producing bio-resourced polymer-grade acrylic acid from glycerol |
| WO2011010035A1 (en) | 2009-07-22 | 2011-01-27 | Arkema France | Method for producing bioresourced acrylic acid from glycerol |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3433831A (en) | Separation and purification of acrylic acid from acetic acid by solvent extraction and azeotropic distillation with a two component solvent-entrainer system | |
| KR100414249B1 (en) | Process for purifying acetic acid | |
| JPH0840974A (en) | Acrylic acid purification method | |
| JP3232678B2 (en) | Acetic acid recovery method | |
| US4076594A (en) | Purification of formic acid by extractive distillation | |
| JP4677066B2 (en) | Post-treatment of liquid crude vinyl acetate | |
| JPH03181440A (en) | Purification of acrylic acid by distillation | |
| JPH11228486A (en) | Method for recovering acetic acid from wastewater containing acetic acid | |
| JP2001322968A (en) | Method for purifying methacrylic acid ester | |
| JP2924563B2 (en) | Purification method of ethyl acetate | |
| JPH0456813B2 (en) | ||
| JP2001002638A (en) | Production of high-purity pyrrolidone compound | |
| JPS58183641A (en) | Purification of methyl (meth)acrylate | |
| JP3608927B2 (en) | Method for producing saturated aliphatic carboxylic acid amide | |
| US6494996B2 (en) | Process for removing water from aqueous methanol | |
| US4098838A (en) | Process for obtaining sulfur free pure naphthalene from bituminous coal tar and thionaphthene as a by-product | |
| JPH04270249A (en) | Purification of dimethyl carbonate | |
| JPS6310691B2 (en) | ||
| JP3832868B2 (en) | Acrylic acid purification method | |
| JP4942878B2 (en) | (Meth) acrylic acid ester purification method | |
| JPS5817464B2 (en) | Method for producing nicotinamide | |
| JP2676910B2 (en) | Method for producing high-purity 0-toluic acid | |
| US4065506A (en) | Continuous process for refining glyoxal | |
| JP2544745B2 (en) | Method for producing α-methylstyrene | |
| JPH10120618A (en) | Method for separating acetic acid from acrylic acid |