JPH11217350A - Production of acrylic acid - Google Patents
Production of acrylic acidInfo
- Publication number
- JPH11217350A JPH11217350A JP32688598A JP32688598A JPH11217350A JP H11217350 A JPH11217350 A JP H11217350A JP 32688598 A JP32688598 A JP 32688598A JP 32688598 A JP32688598 A JP 32688598A JP H11217350 A JPH11217350 A JP H11217350A
- Authority
- JP
- Japan
- Prior art keywords
- acrylic acid
- aqueous solution
- azeotropic dehydration
- column
- tower
- 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.)
- Granted
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はプロピレンやアクロ
レインの接触気相酸化により得られるアクリル酸含有水
溶液から、重合を防止しつつアクリル酸を分離するアク
リル酸の製造方法に関するものである。The present invention relates to a method for producing acrylic acid by separating acrylic acid from an aqueous solution containing acrylic acid obtained by catalytic gas-phase oxidation of propylene or acrolein while preventing polymerization.
【０００２】[0002]
【従来の技術】アクリル酸は、現在工業的にはプロピレ
ンおよび／またはアクロレインの接触気相酸化によって
製造されている。接触気相酸化は分子状酸素及び水蒸気
の存在下に固体触媒を用いて実施されるため、通常酸化
生成物はアクリル酸含有水溶液の状態として得られる。Acrylic acid is currently produced industrially by catalytic gas phase oxidation of propylene and / or acrolein. Since the catalytic gas-phase oxidation is carried out using a solid catalyst in the presence of molecular oxygen and water vapor, the oxidation product is usually obtained as an aqueous solution containing acrylic acid.
【０００３】該アクリル酸含有水溶液はアクリル酸の
他、酢酸、蟻酸、ホルマリン、フルフラール、アクロレ
イン、アセトアルデヒド、プロピオン酸、マレイン酸、
ベンズアルデヒド、プロトアネモニン等の副生成物を数
多く含有している。The aqueous solution containing acrylic acid, in addition to acrylic acid, acetic acid, formic acid, formalin, furfural, acrolein, acetaldehyde, propionic acid, maleic acid,
It contains many by-products such as benzaldehyde and protoanemonin.
【０００４】このようなアクリル酸含有水溶液からアク
リル酸を回収するには、まず、アクリル酸含有水溶液か
ら水を除去する必要がある。アクリル酸含有水溶液から
水を除去する方法としては、ケトン、酢酸エステル、酪
酸エステル、芳香族炭化水素などの溶剤を用いた溶剤抽
出法（例えば特公昭４６−１８７２８号公報、特公昭４
９−３４９６６号公報、特開昭４８−６２７１２号公
報、特開昭４９−５９１５号公報等）や、トルエン、メ
チルイソブチルケトンなどの水と共沸する溶剤を用いた
共沸脱水法（例えば特開昭４９−７２１６号公報、特公
昭６３−１０６９１号公報、特開平３−１８１４４０号
公報、特公昭４１−１１２４７号公報等）が知られてい
るが、近年、プロピレンおよび／またはアクロレインの
接触気相酸化触媒の性能向上および酸化条件の改善等に
よりアクリル酸含有水溶液中のアクリル酸濃度が４０〜
７０重量％と著しく高められた事もあり、経済的理由よ
り、共沸脱水法が主流となってきた。In order to recover acrylic acid from such an aqueous solution containing acrylic acid, first, it is necessary to remove water from the aqueous solution containing acrylic acid. As a method for removing water from the aqueous solution containing acrylic acid, a solvent extraction method using a solvent such as ketone, acetate, butyrate, or aromatic hydrocarbon (for example, Japanese Patent Publication No. 46-18728, Japanese Patent Publication No. Sho 4
9-34966, JP-A-48-62712, JP-A-49-5915, etc.) and an azeotropic dehydration method using a solvent azeotropic with water such as toluene and methyl isobutyl ketone (for example, JP-A-49-7216, JP-B-63-10691, JP-A-3-181440, JP-B-41-11247, etc.) are known, but in recent years, the contact air of propylene and / or acrolein has been known. The acrylic acid concentration in the acrylic acid-containing aqueous solution is increased to 40-
The azeotropic dehydration method has become mainstream for economic reasons, as it has been significantly increased to 70% by weight.
【０００５】しかしながら、数多くの副生成物を含有す
るアクリル酸含有水溶液を直接脱水塔へ供給して蒸留に
より脱水する場合、アクリル酸は熱、光、過酸化物、ア
ルデヒド類の不純物等によって容易に重合を起こす性質
を有しているため、多量の重合物が発生し、これら重合
物が蒸留塔リボイラー伝熱面に付着し伝熱性能の低下を
もたらすばかりでなく、蒸留塔の閉塞を起こし、操業を
停止せざるを得ない等の状況を呈することが知られてい
る。それ故、重合をいかに抑制するかが工業的には極め
て重要である。[0005] However, when an acrylic acid-containing aqueous solution containing many by-products is directly supplied to a dehydration tower and dehydrated by distillation, acrylic acid is easily subjected to heat, light, peroxides, impurities of aldehydes and the like. Because it has the property of causing polymerization, a large amount of polymers are generated, and these polymers adhere not only to the heat transfer surface of the distillation column reboiler, resulting in a decrease in heat transfer performance, but also to blockage of the distillation column, It is known to exhibit such a situation that the operation must be stopped. Therefore, how to suppress the polymerization is extremely important industrially.
【０００６】従来、アクリル酸の重合防止法の１つとし
て、アクリル酸含有液に重合防止剤を添加することが、
古くから提案され実施されている。代表的な重合防止剤
としては、ハイドロキノン、ハイドロキノンモノメチル
エーテル等のフェノール類、フェノチアジン、ジフェニ
ルアミン等のアミン類、ジブチルジチオカルバミン酸銅
等の銅塩、酢酸マンガン等のマンガン塩、ニトロ化合
物、ニトロソ化合物等が知られている。そして、これら
の重合防止剤は単独あるいは組み合わせて用いたり、或
いは分子状酸素含有ガスと併用する等して使用されてい
る。Conventionally, as one of the methods for preventing the polymerization of acrylic acid, the addition of a polymerization inhibitor to a liquid containing acrylic acid has been proposed.
It has been proposed and implemented since ancient times. Representative polymerization inhibitors include phenols such as hydroquinone and hydroquinone monomethyl ether; amines such as phenothiazine and diphenylamine; copper salts such as copper dibutyldithiocarbamate; manganese salts such as manganese acetate; nitro compounds; and nitroso compounds. Are known. These polymerization inhibitors are used alone or in combination, or used in combination with a molecular oxygen-containing gas.
【０００７】また、近年ではアクリル酸の重合特性が重
要な因子となる高吸水性樹脂および高分子凝集剤製造用
の用途に於いてアルデヒド等の不純物が問題となること
より（１）アルデヒド類を含有する粗製アクリル酸に、
芳香族アミン、脂肪族アミン、その他アミド、イミン、
イミド、ポリアミン等のアミン類を添加した後、蒸留を
行い、アルデヒド類をアクリル酸から除去するアクリル
酸の精製方法（特公昭４８−３１０８７号公報）、
（２）プロピレン及び／又はアクロレインの接触酸化反
応により得られるアクリル酸にアンモニア、メチルアミ
ン、エチルアミン、ジメチルアミン、ジエチルアミン又
はこれらの塩よりなる群から選ばれた１種又は２種以上
を添加するアクリル酸の重合防止法及び／又はアクリル
酸中に含まれるアルデヒド類の分解法（特開昭５０−５
０３１４号公報）、（３）プロピレン及び／又はアクロ
レインの接触気相酸化によって得られるアクリル酸を、
ヒドラジン類化合物またはアミン類化合物を吸着させた
モレキュラーシーブにて処理し、アクリル酸中に含まれ
ているアルデヒド類を分解除去するアクリル酸の精製方
法（特開昭５６−１８９３４号公報）、（４）アルデヒ
ドで汚染されたアクリル酸に、第１級アミンおよび／ま
たはその塩に加えて、少なくとも１種の有機スルホン酸
および／またはその塩を添加し、この混合物からアクリ
ル酸を蒸留により分離するアクリル酸の精製方法（特開
平７−１４９６８７号公報）、（５）プロピレン及び／
又はアクロレインの接触気相酸化によって得られたアク
リル酸含有酸化生成液を共沸脱水処理したのち、脱アル
デヒド剤を添加してアクリル酸を蒸留精製するに当た
り、共沸脱水処理液に、脂肪族アミン、複素環式アミン
及び芳香族モノアミンの中から選ばれた少なくとも一種
のアミン類と脱アルデヒド剤とを添加するアクリル酸の
製造方法（特開平９−２０８５１５号公報）等が提案さ
れている。Further, in recent years, impurities such as aldehydes have become a problem in the production of superabsorbent resins and polymer flocculants in which the polymerization characteristics of acrylic acid are an important factor. The crude acrylic acid contained
Aromatic amines, aliphatic amines, other amides, imines,
After adding amines such as imides and polyamines, distillation is carried out to remove aldehydes from acrylic acid. A method for purifying acrylic acid (Japanese Patent Publication No. 48-31087),
(2) Acrylic obtained by adding one or more selected from the group consisting of ammonia, methylamine, ethylamine, dimethylamine, diethylamine and salts thereof to acrylic acid obtained by a catalytic oxidation reaction of propylene and / or acrolein. Method for preventing polymerization of acid and / or method for decomposing aldehydes contained in acrylic acid (JP-A-50-5
No. 0314), (3) acrylic acid obtained by catalytic gas-phase oxidation of propylene and / or acrolein,
A method for purifying acrylic acid by treating with a molecular sieve to which a hydrazine compound or an amine compound is adsorbed to decompose and remove aldehydes contained in acrylic acid (JP-A-56-18934); A) an acrylic acid which is obtained by adding at least one organic sulfonic acid and / or a salt thereof to an aldehyde-contaminated acrylic acid in addition to a primary amine and / or a salt thereof, and separating the acrylic acid from the mixture by distillation; A method for purifying an acid (JP-A-7-149687), (5) propylene and / or
Alternatively, an acrylic acid-containing oxidation product solution obtained by catalytic gas phase oxidation of acrolein is subjected to azeotropic dehydration treatment, and then an acrylic acid is distilled and purified by adding a dealdehyde agent. And a method for producing acrylic acid by adding at least one amine selected from heterocyclic amines and aromatic monoamines and a dealdehyde agent (JP-A-9-208515).
【０００８】これらの方法はアクリル酸中に含まれる微
量アルデヒド類の除去のためアミン類を添加した後、該
液を蒸留することによって、アルデヒド類の少ないアク
リル酸を得るものであったり、アルデヒド類を含有する
アクリル酸をアミン類化合物を吸着させたモレキュラー
シーブにて処理するものに関するものである。しかしな
がら、アルデヒド類を含有するアクリル酸にアミン類を
添加して直接蒸留すると、蒸留塔で重合が生じ易いこと
やタール状物質が生成する等の問題がある。また、アミ
ン類化合物を吸着させたモレキュラーシーブにて処理す
る場合、モレキュラーシーブの寿命等の問題があり、必
ずしも経済的方法とは言いがたい。[0008] In these methods, an amine is added to remove a trace amount of aldehydes contained in acrylic acid, and then the solution is distilled to obtain acrylic acid having a small amount of aldehydes. The present invention relates to a method of treating acrylic acid containing a compound with a molecular sieve having an amine compound adsorbed thereon. However, if amines are added to acrylic acid containing aldehydes and distilled directly, there are problems such as easy polymerization in the distillation column and formation of tar-like substances. Further, when the treatment is carried out with a molecular sieve to which an amine compound is adsorbed, there is a problem such as the life of the molecular sieve, and it is not necessarily an economical method.
【０００９】[0009]
【発明が解決しようとする課題】本発明の課題は、プロ
ピレン及び／又はアクロレインの接触気相酸化によって
得られるアクリル酸含有水溶液を共沸脱水処理してアク
リル酸を分離し、アクリル酸を製造する方法に於いて、
いかに重合を防止して、該アクリル酸含有水溶液より水
を除去する共沸脱水塔、更には得られるアクリル酸に含
有される酢酸等の不純物を除去するための低沸蒸留塔や
マレイン酸等の高沸不純物を除去し製品であるアクリル
酸を得るための製品化塔での重合付着物を軽減し、長期
に操業を停止することなく安定してアクリル酸を製造し
得る方法を提供するかにある。SUMMARY OF THE INVENTION An object of the present invention is to produce acrylic acid by subjecting an aqueous solution containing acrylic acid obtained by catalytic gas-phase oxidation of propylene and / or acrolein to azeotropic dehydration to separate acrylic acid. In the method
How to prevent polymerization, azeotropic dehydration tower to remove water from the aqueous solution containing acrylic acid, furthermore, low boiling distillation column and maleic acid etc. to remove impurities such as acetic acid contained in acrylic acid obtained Do you want to provide a method that can reduce the amount of polymer deposits in a commercialization tower for removing acrylic acid as a product by removing high boiling impurities and stably produce acrylic acid without stopping the operation for a long time? is there.
【００１０】[0010]
【課題を解決するための手段】かかる事情下に鑑み、本
発明者等はプロピレン及び／又はアクロレインの接触気
相酸化によって得られるアクリル酸含有水溶液を共沸脱
水処理してアクリル酸を分離し、アクリル酸を製造する
方法に於いて、共沸脱水塔や更には共沸脱水塔より得ら
れたアクリル酸中に含有される不純物を除去するための
蒸留塔で発生する重合付着物を軽減するべく鋭意検討し
た結果、該アクリル酸水溶液を直接共沸脱水塔へ供給し
ないで、一旦、蒸発させて得られるアクリル酸含有蒸気
を共沸脱水塔へ供給して共沸脱水する場合には、上記課
題が解決し得ることを見いだし、本発明を完成するに至
った。In view of such circumstances, the present inventors separated acrylic acid by azeotropic dehydration of an aqueous solution containing acrylic acid obtained by catalytic gas phase oxidation of propylene and / or acrolein. In the method for producing acrylic acid, in order to reduce polymerization deposits generated in an azeotropic dehydration column or a distillation column for removing impurities contained in acrylic acid obtained from the azeotropic dehydration column. As a result of intensive study, the acrylic acid aqueous solution is not directly supplied to the azeotropic dehydration tower, but the acrylic acid-containing vapor obtained by evaporation is once supplied to the azeotropic dehydration tower to perform the azeotropic dehydration. Have been found to be able to solve the problem, and have completed the present invention.
【００１１】すなわち、本発明は、プロピレン及び／又
はアクロレインの接触気相酸化によって得られるアクリ
ル酸含有水溶液を共沸脱水処理してアクリル酸を分離
し、アクリル酸を製造する方法に於いて、共沸脱水処理
前にアクリル酸含有水溶液を蒸発処理し、得られたアク
リル酸含有蒸気を共沸脱水処理することを特徴とするア
クリル酸の製造方法を提供するにある。That is, the present invention relates to a method for producing acrylic acid by separating an acrylic acid by azeotropic dehydration of an aqueous solution containing acrylic acid obtained by catalytic gas-phase oxidation of propylene and / or acrolein. An object of the present invention is to provide a method for producing acrylic acid, which comprises subjecting an acrylic acid-containing aqueous solution to an evaporation treatment before the boiling dehydration treatment, and subjecting the obtained acrylic acid-containing vapor to an azeotropic dehydration treatment.
【００１２】[0012]
【発明の実施の形態】本発明の実施に際しては、プロピ
レンおよび／又はアクロレインの接触気相酸化によって
得られるアクリル酸含有水溶液が用いられる。該アクリ
ル酸含有水溶液はプロピレンの一段酸化法によって得ら
れるものであってもよく、二段酸化法によって得られる
ものであってもよく、更には生ガス循環方式によるもの
でも良く排燃ガス循環方式によるものであっても良い。DESCRIPTION OF THE PREFERRED EMBODIMENTS In carrying out the present invention, an aqueous solution containing acrylic acid obtained by catalytic gas-phase oxidation of propylene and / or acrolein is used. The acrylic acid-containing aqueous solution may be obtained by a one-stage oxidation method of propylene, may be obtained by a two-stage oxidation method, and may be a raw gas circulation system or an exhaust gas circulation system. It may be due to.
【００１３】プロピレンおよび／又はアクロレインを水
蒸気の存在下に固体触媒を用いて分子状酸素にて接触気
相酸化するとアクリル酸、水の他に各種アルデヒド類、
各種有機酸類が生成するアクリル酸含有水溶液の主な組
成は、用いる触媒の種類や反応条件などによって異なる
が、アクリル酸４０〜７０重量％、水２０〜５６重量
％、酢酸２〜１０重量％程度である。When propylene and / or acrolein are subjected to catalytic gas phase oxidation with molecular oxygen using a solid catalyst in the presence of water vapor, various aldehydes, in addition to acrylic acid and water,
The main composition of the aqueous solution of acrylic acid containing various organic acids varies depending on the type of catalyst used and reaction conditions, but is about 40 to 70% by weight of acrylic acid, about 20 to 56% by weight of water, and about 2 to 10% by weight of acetic acid. It is.
【００１４】本発明においては、該アクリル酸含有水溶
液を従来法の如く、直接、共沸脱水処理するのではな
く、まず蒸発器にて蒸発処理し、得られるアクリル酸の
含有蒸気を共沸脱水処理することを特徴とするものであ
る。本発明に於いて使用する蒸発器の形式には特に制限
はないが、通常、濡壁塔方式、強制循環方式のものが使
用される。また蒸発操作圧力にも特に制限はないが、発
生した蒸気を次の共沸脱水塔へ導く必要があるため、共
沸脱水塔の操作圧力よりも若干高めで操作することが好
ましい。蒸発器は１段もしくは多段で用いられる。アク
リル酸の回収率を上げるためには多段にすることが好ま
しい。蒸発器での蒸発率については、少なくとも９０％
以上とすることが好ましい。蒸発器の缶残液はダイマー
分解等のアクリル酸回収工程に供給し、アクリル酸を回
収することが好ましい。In the present invention, the acrylic acid-containing aqueous solution is not directly subjected to azeotropic dehydration treatment as in the conventional method, but is first subjected to evaporative treatment in an evaporator, and the resulting acrylic acid-containing vapor is subjected to azeotropic dehydration. It is characterized by processing. The type of the evaporator used in the present invention is not particularly limited, but usually a wet wall tower type or a forced circulation type is used. The evaporation operation pressure is not particularly limited, but it is preferable to operate the operation pressure slightly higher than the operation pressure of the azeotropic dehydration tower because it is necessary to guide generated steam to the next azeotropic dehydration tower. The evaporator is used in one stage or multiple stages. In order to increase the recovery rate of acrylic acid, it is preferable to use multiple stages. At least 90% of the evaporation rate in the evaporator
It is preferable to make the above. It is preferable that the bottom liquid of the evaporator is supplied to an acrylic acid recovery step such as dimer decomposition to recover acrylic acid.
【００１５】蒸発操作においては、従来アクリル酸の重
合防止剤として知られているハイドロキノン、ハイドロ
キノンモノメチルエーテル等のフェノール類、フェノチ
アジン、ジフェニルアミン等のアミン類、ジブチルジチ
オカルバミン酸銅等の銅塩、酢酸マンガン等のマンガン
塩、ニトロ化合物、ニトロソ化合物等を添加し、更に分
子状酸素含有ガスを吹き込むことが好ましい。In the evaporating operation, phenols such as hydroquinone and hydroquinone monomethyl ether, amines such as phenothiazine and diphenylamine, copper salts such as copper dibutyldithiocarbamate, manganese acetate, etc. It is preferable to add a manganese salt, a nitro compound, a nitroso compound and the like, and further blow a molecular oxygen-containing gas.
【００１６】更に、本発明の効果をより高めるために
は、アクリル酸含有水溶液を蒸発させる前に、該アクリ
ル酸含有水溶液にアンモニア、第１級アミン類、第２級
アミン類、ヒドラジン類、尿素又はこれらの塩よりなる
群から選ばれた１種または２種以上を添加するのが望ま
しい。特にトリエチレンテトラミンやジエチレントリア
ミンを添加するのが好ましい。第１級アミン類、第２級
アミン類としてはエタノールアミン、ジエタノ−ルアミ
ン、ジエチルアミン、ヘキサメチレンジアミン、オクチ
ルアミン、トリエチレンテトラミン、ジエチレントリア
ミン、プロピルアミン、ヘキシルアミン、トリエチレン
ペンタミン、テトラエチレンペンタミン、エチレンジア
ミン等の脂肪族アミン類、シクロヘキシルアミン、シク
ロペンチルアミン等の脂環式アミン類、フェニレンジア
ミン等の芳香族アミン類等が挙げられる。ヒドラジン類
としては、ヒドラジン、フェニルヒドラジン等が挙げら
れる。Further, in order to further enhance the effects of the present invention, ammonia, primary amines, secondary amines, hydrazines, urea, and the like are added to the acrylic acid-containing aqueous solution before the acrylic acid-containing aqueous solution is evaporated. Alternatively, it is desirable to add one or more selected from the group consisting of these salts. In particular, it is preferable to add triethylenetetramine or diethylenetriamine. Primary amines and secondary amines include ethanolamine, diethanolamine, diethylamine, hexamethylenediamine, octylamine, triethylenetetramine, diethylenetriamine, propylamine, hexylamine, triethylenepentamine, tetraethylenepentamine , Aliphatic amines such as ethylenediamine, alicyclic amines such as cyclohexylamine and cyclopentylamine, and aromatic amines such as phenylenediamine. Hydrazines include hydrazine, phenylhydrazine and the like.
【００１７】アクリル酸含有水溶液にアンモニア、第１
級アミン類、第２級アミン類、ヒドラジン類、尿素又は
これらの塩よりなる群から選ばれた１種または２種以上
を添加する場合には、これらの化合物を該アクリル含有
水溶液に対し約１０〜１０００ｐｐｍ程度添加すればよ
い。添加温度は通常約１０〜約１００℃程度、好ましく
は約３０〜８０℃の範囲である。更に、接触時間は特に
制限はないが約５〜約１５０分程度である。添加位置に
ついても、特に制限はないが、プロピレンおよび／又は
アクロレインの接触気相酸化ガスの吸収塔缶液或いはア
クリル酸含有水溶液タンクが好ましい。混合方法は添加
物とアクリル酸含有水溶液とが十分混合されれば良く、
例えば、スタティックミキサー、ラインミキサー、攪拌
機、ポンプ循環ラインを有するアクリル酸含有水溶液貯
蔵タンク等が挙げられる。The aqueous solution containing acrylic acid contains ammonia,
When one or more selected from the group consisting of secondary amines, secondary amines, hydrazines, urea and salts thereof are added, these compounds are added to the acrylic-containing aqueous solution in an amount of about 10%. What is necessary is just to add about 1000 ppm. The addition temperature is usually in the range of about 10 to about 100C, preferably about 30 to 80C. Further, the contact time is not particularly limited, but is about 5 to about 150 minutes. The addition position is not particularly limited, either, but it is preferable to use a liquid in an absorption tower or an aqueous solution tank containing acrylic acid for contact gas-phase oxidizing gas of propylene and / or acrolein. The mixing method is sufficient if the additive and the acrylic acid-containing aqueous solution are sufficiently mixed,
For example, a storage tank for an aqueous solution containing acrylic acid having a static mixer, a line mixer, a stirrer, and a pump circulation line may be used.
【００１８】次に、得られたアクリル酸含有水溶液の蒸
気を共沸脱水塔へ導き、主として水を除去する。この共
沸脱水塔での処理方法については特に制限はなく、従
来、アクリル酸の製造において慣用されている方法を用
いることができる。例えば、共沸剤としてトルエン、メ
チルイソブチルケトン、キシレン、エチルベンゼン、ヘ
プタン及びこれらの混合物などを用い、約１００〜約２
００Ｔｏｒｒ程度の真空下で共沸脱水を行う。この共沸
脱水塔で処理することによって、共沸脱水塔塔底液中の
水分濃度は通常１０００ｐｐｍ以下となる。他方、共沸
脱水塔の塔頂からは、水、酢酸、共沸剤、低沸点物のア
ルデヒド類が留去される。水と共沸剤は相互に溶解しな
いことが望ましく、留出液の水相は系外へ導き、一方油
相は還流液として共沸脱水塔へもどされ循環使用され
る。Next, the vapor of the obtained acrylic acid-containing aqueous solution is led to an azeotropic dehydration tower to mainly remove water. The treatment method in the azeotropic dehydration tower is not particularly limited, and a method conventionally used in the production of acrylic acid can be used. For example, toluene, methyl isobutyl ketone, xylene, ethylbenzene, heptane, a mixture thereof and the like are used as an azeotropic agent, and about 100 to about 2
The azeotropic dehydration is performed under a vacuum of about 00 Torr. By treating in this azeotropic dehydration tower, the water concentration in the bottom liquid of the azeotropic dehydration tower is usually 1000 ppm or less. On the other hand, water, acetic acid, an azeotropic agent, and low-boiling aldehydes are distilled off from the top of the azeotropic dehydration tower. It is desirable that the water and the azeotropic agent do not dissolve in each other, and the aqueous phase of the distillate is led out of the system, while the oil phase is returned to the azeotropic dehydration column as a reflux liquid and recycled.
【００１９】共沸脱水塔の缶出液は、次いで、通常、低
沸分離塔に導き、水、酢酸、共沸剤などの低沸点物を除
去する。低沸分離塔の缶出液は必要に応じて更に蒸留精
製して製品としてのアクリル酸を得る。他方、低沸分離
塔の留出液中に含まれるアクリル酸、共沸剤、酢酸は更
に蒸留して酢酸等を分離した後、アクリル酸及び共沸剤
はアクリル酸含有液として共沸脱水塔或いは低沸分離塔
等の前工程に導き、回収してもよい。Next, the bottom product of the azeotropic dehydration column is usually led to a low-boiling separation column to remove low-boiling substances such as water, acetic acid and an azeotropic agent. The bottom product of the low-boiling separation column is further purified by distillation, if necessary, to obtain acrylic acid as a product. On the other hand, acrylic acid, azeotropic agent, and acetic acid contained in the distillate of the low-boiling separation column are further distilled to separate acetic acid and the like. Alternatively, it may be led to a previous step such as a low-boiling separation column and recovered.
【００２０】[0020]
【発明の効果】以上詳述した本発明によれば、従来一般
的に行われているアクリル酸水溶液を直接共沸脱水塔へ
供給し脱水蒸留をする場合には、共沸脱水塔の回収部お
よびリボイラーにおいて重合物の生成や、タール状物質
の生成が顕著であり、長期安定運転が困難であるが、本
発明の如く、蒸留装置前に蒸発装置をもちいる場合には
共沸脱水塔での蒸留付着物は著しく減少し、充填塔やシ
ーブトレイ等、さらには熱源供給装置としてのリボイラ
ーの伝熱面等、複雑な構造物に付着した重合物の除去頻
度が減少すると共に、該蒸発装置は蒸留装置に比較し装
置構造が簡単で、設備費も廉価であることより、蒸発器
を２系列設置して重合物等が器壁に付着すれば切り替え
て使用すればよく、その場合においても、停止中の蒸発
器はアルカリ洗浄或いはジェット洗浄等の方法により容
易に除去し得る。また、共沸脱水塔塔底液を更に蒸留す
る低沸分離塔、さらには製品化塔の蒸留付着物も減少し
得るので、その産業上の利用価値は頗る大である。According to the present invention described in detail above, when a conventional aqueous acrylic acid solution is directly supplied to an azeotropic dehydration tower to perform dehydration distillation, the recovery section of the azeotropic dehydration tower is required. And in the reboiler, the production of polymers and the production of tar-like substances are remarkable, and long-term stable operation is difficult.However, as in the present invention, when an evaporator is used before the distillation apparatus, an azeotropic dehydration column is used. The amount of polymer adhering to complicated structures such as packed towers, sieve trays, and the heat transfer surface of a reboiler as a heat source supply device is reduced, and the evaporator is Compared with the distillation apparatus, the apparatus structure is simpler and the equipment cost is low.Therefore, if evaporators are installed in two lines and the polymer or the like adheres to the vessel wall, it can be switched and used. Alkaline cleaning of evaporator while stopped There may be easily removed by way of the jet cleaning or the like. Further, since the low-boiling separation column for further distilling the bottom liquid of the azeotropic dehydration column and the distillation deposits on the commercialization column can be reduced, the industrial use value thereof is extremely large.
【００２１】[0021]
【実施例】次に、本発明を実施例によって更に詳しく説
明するが本発明は、これらの実施例によってなんら限定
されるものではない。Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
【００２２】実施例１ プロピレンの２段接触気相酸化により得られた、アクリ
ル酸５５重量％、水４１重量％、酢酸３重量％、その他
不純物としてアクロレイン、ホルマリン、フルフラー
ル、アセトアルデヒド、プロピオン酸、マレイン酸、ベ
ンズアルデヒド、プロトアネモニン等をそれぞれ数１０
ｐｐｍ〜数１０００ｐｐｍ含有するアクリル酸含有水溶
液を、２ｍ2 の濡壁式蒸発器に５０ｋｇ／Ｈｒの速度で
供給し、１．１ｋｇ／ｃｍ2 の飽和スチームにて加熱
し、発生した蒸気を直接共沸脱水塔に供給した。濡壁式
蒸発器の缶液は、ポンプにて該蒸発器へ循環させる方式
とし、一部の缶液はポンプにて系外へ抜き出した。該蒸
発器の缶にも空気を炊き上げ蒸気に対して０．３容量％
供給した。又、蒸発器に缶液中のハイドロキノンとジブ
チルジチオカルバミン酸銅濃度がそれぞれ約２０００ｐ
ｐｍ、１００ｐｐｍとなるよう重合禁止剤を供給した。Example 1 Acrylic acid 55% by weight, water 41% by weight, acetic acid 3% by weight obtained by two-stage catalytic gas phase oxidation of propylene, and other impurities such as acrolein, formalin, furfural, acetaldehyde, propionic acid, and maleic acid. Acid, benzaldehyde, protoanemonin, etc.
Acrylic acid-containing aqueous solution containing from 1 ppm to several 1000 ppm is supplied to a 2 m 2 wet wall type evaporator at a rate of 50 kg / Hr, heated with 1.1 kg / cm 2 saturated steam, and the generated steam is directly It was supplied to a boiling dehydration tower. The can solution of the wet wall type evaporator was circulated to the evaporator by a pump, and a part of the can solution was drawn out of the system by a pump. The air in the evaporator can is also cooked and 0.3% by volume based on the steam
Supplied. In addition, the concentration of hydroquinone and copper dibutyldithiocarbamate in the bottom of the evaporator was about 2000p.
pm, a polymerization inhibitor was supplied to 100 ppm.
【００２３】一方、次工程である共沸脱水蒸留塔は内径
２００ｍｍのステンレス製で、蒸留塔内には０Ｐのカス
ケードミニリング（ドット・ウェル社製）が濃縮部に５
ｍ、回収部に２ｍ充填され、塔底部に２ｍ2 のリボイラ
ー、塔頂部には４ｍ2 のコンデンサーが設置され、コン
デンサーの出口は真空調整装置に接続され構成されてお
り、共沸剤としてはトルエンを用い、缶液中のトルエン
濃度が１７重量％となるよう還流ラインより供給した。
リボイラーは１．１ｋｇ／ｃｍ2 の飽和スチームにて加
熱し、加熱量の調整はスチーム量により制御した。塔頂
部のコンデンサーで凝縮された留出液はデカンターで静
置分離した後、共沸剤相は全量還流し、水相は系外へ抜
き出した。また、塔底液は液面が一定となるようにポン
プで抜き出し後述の低沸分離塔原料に用いた。該共沸脱
水蒸留塔に於いては塔頂圧力を１５０ｍｍＨｇに制御
し、塔頂より重合禁止剤として、フェノチアジン、ジブ
チルジチオカルバミン酸銅を塔底液中の濃度がそれぞれ
約２００ｐｐｍ、１００ｐｐｍとなるように供給した。
又、リボイラーには空気を炊き上げ蒸気に対して０．３
容量％供給した。On the other hand, the azeotropic dehydration distillation column, which is the next step, is made of stainless steel having an inner diameter of 200 mm, and a 0P cascade mini ring (manufactured by Dot Well) is provided in the distillation column in the enrichment section.
m, 2 m filling in the recovery section, 2 m 2 reboiler at the bottom of the tower, 4 m 2 of condenser at the top, the outlet of the condenser is connected to a vacuum controller, and the entrainer is toluene. And supplied from a reflux line so that the toluene concentration in the bottom liquid was 17% by weight.
The reboiler was heated with 1.1 kg / cm 2 of saturated steam, and the amount of heating was controlled by the amount of steam. The distillate condensed in the condenser at the top of the tower was separated by standing in a decanter, the entire azeotropic agent was refluxed, and the aqueous phase was drawn out of the system. The bottom liquid was withdrawn with a pump so that the liquid level was constant, and was used as a low-boiling separation column material described later. In the azeotropic dehydration distillation column, the top pressure was controlled at 150 mmHg, and phenothiazine and copper dibutyldithiocarbamate were used as polymerization inhibitors from the top of the column such that the concentrations in the bottom solution were about 200 ppm and 100 ppm, respectively. Supplied.
In addition, the reboiler cooks air and raises 0.3% against steam.
% Supplied by volume.
【００２４】このようにして、蒸発器及び共沸脱水蒸留
塔の運転を２３日間継続し行った。この時の共沸脱水塔
の塔頂温度は約４５℃、塔底温度は約８０℃、デカンタ
ーの水相の抜き出し量は２１ｋｇ／Ｈｒで、その組成は
水９５重量％、酢酸４重量％、アクリル酸０．１重量％
であった。共沸脱水塔の塔底からの抜き出し量は３１ｋ
ｇ／Ｈｒで、水０．０５重量％、酢酸２重量％、アクリ
ル酸８０重量％、トルエン１７重量％及び重合禁止剤等
が含まれていた。又、蒸発器の缶液抜き出し量は３ｋｇ
／Ｈｒで、缶液には水１０重量％、アクリル酸（ダイマ
ー含み）７０重量％、酢酸４重量％及び重合禁止剤等の
高沸物が含まれていた。２３日間連続運転した後、蒸発
器および共沸脱水塔を停止して解体点検したところ、蒸
発器内面に僅かの重合物らしき物の付着と回収部にほん
の僅かの黒いタール状物質の付着が見られた。リボイラ
ーにも僅かの付着物が見られた。各部位の重合物を約８
０℃、２時間真空乾燥し、乾燥重量を測定した。その測
定結果を表１に示す。Thus, the operation of the evaporator and the azeotropic dehydration distillation column was continued for 23 days. At this time, the top temperature of the azeotropic dehydration column is about 45 ° C., the bottom temperature is about 80 ° C., the amount of the water phase withdrawn from the decanter is 21 kg / Hr, and the composition is 95% by weight of water, 4% by weight of acetic acid, Acrylic acid 0.1% by weight
Met. Amount of extraction from the bottom of the azeotropic dehydration tower is 31k
g / Hr, contained 0.05% by weight of water, 2% by weight of acetic acid, 80% by weight of acrylic acid, 17% by weight of toluene and a polymerization inhibitor. Also, the withdrawal volume of evaporator can is 3 kg.
/ Hr, the can solution contained 10 wt% of water, 70 wt% of acrylic acid (including dimer), 4 wt% of acetic acid, and high boiling substances such as polymerization inhibitors. After continuous operation for 23 days, the evaporator and the azeotropic dehydration tower were stopped and dismantled and inspected. Was done. Slight deposits were also found on the reboiler. Approximately 8
After vacuum drying at 0 ° C. for 2 hours, the dry weight was measured. Table 1 shows the measurement results.
【００２５】次に、共沸脱水塔の塔底より抜き出された
液を用い、供給速度３００ｇ／Ｈｒで低沸分離塔に供給
し低沸点物を蒸留分離した。低沸分離塔は、蒸留塔部が
内径３０ｍｍのガラス製円筒で、底部にはリボイラーと
して２リットルのフラスコが、塔頂部にはコンデンサー
が設置されており、コンデンサーの出口は真空調整装置
に接続され、蒸留塔の濃縮部、回収部には３ｍｍのステ
ンレス製ディクソンバッキンがそれぞれ１５ｃｍ、６０
ｃｍ充填されている。塔頂部のコンデンサーで凝縮され
た留出液にフェノチアジン、ジブチルジチオカルバミン
酸銅濃度がそれぞれ約２００ｐｐｍ、３３ｐｐｍとなる
よう重合禁止剤をトルエンに希釈し供給した後、該留出
液の一部は低沸分離塔の還流液として用い、残りの留出
液は系外へ抜き出した。リボイラーであるフラスコの加
熱はオイルバスにて行い、留出量の調整はオイルバス温
度にて行った。また塔底のフラスコに空気を炊き上げ蒸
気に対して０．３容量％吹き込んだ。フラスコ内の液面
はフラスコよりポンプで塔底液を抜き出すことにより一
定に保った。低沸分離塔の運転は塔頂圧力７０ｍｍＨ
ｇ、還流比を４に制御し、塔頂温度は約６３℃、塔底温
度は約８２℃で２３日間継続した。留出液の抜出し量は
１００ｇ／Ｈｒで、その組成は酢酸６重量％、アクリル
酸４０重量％、トルエン５４重量％であった。低沸分離
塔の塔底からの抜き出し量は２００ｇ／Ｈｒでアクリル
酸９８重量％、トルエン数ｐｐｍ、酢酸２００ｐｐｍ及
び高沸点物や重合禁止剤等が含まれていた。２３日間連
続運転した後、低沸分離塔を停止して解体点検したとこ
ろ、濃縮部の充填物であるデクソンパッキンの重量が
０．３５ｇ増加していた。回収部の充填物重量も０．３
５ｇ増加していた。リボイラーであるフラスコの重量も
０．１０ｇ増加していた。しかしながら、いずれの部位
も目で確認できるほどの重合物の発生は認められなかっ
た。Next, the liquid extracted from the bottom of the azeotropic dehydration column was supplied to a low-boiling separation column at a feed rate of 300 g / Hr, and low-boiling substances were separated by distillation. In the low-boiling separation column, the distillation column is a glass cylinder with an inner diameter of 30 mm, a 2 liter flask is installed at the bottom as a reboiler, and a condenser is installed at the top. The outlet of the condenser is connected to a vacuum controller. In the enrichment section and the recovery section of the distillation column, a 3 mm stainless steel Dickson backing was 15 cm, 60 mm, respectively.
cm. After diluting the polymerization inhibitor in toluene so that the concentrations of phenothiazine and copper dibutyldithiocarbamate become about 200 ppm and 33 ppm, respectively, to the distillate condensed by the condenser at the top of the column, the distillate is partially distilled. It was used as a reflux for the separation tower, and the remaining distillate was drawn out of the system. The reboiler flask was heated in an oil bath, and the amount of distillate was adjusted at the oil bath temperature. Air was cooked into the flask at the bottom of the tower and 0.3% by volume of the steam was blown. The liquid level in the flask was kept constant by extracting the bottom liquid from the flask with a pump. The operation of the low boiling separation column is 70 mmH
g, the reflux ratio was controlled at 4, the top temperature was about 63 ° C., and the bottom temperature was about 82 ° C., which was continued for 23 days. The amount of distillate withdrawn was 100 g / Hr, and the composition was 6% by weight of acetic acid, 40% by weight of acrylic acid, and 54% by weight of toluene. The amount extracted from the bottom of the low-boiling separation column was 200 g / Hr, and contained 98% by weight of acrylic acid, several ppm of toluene, 200 ppm of acetic acid, and high-boiling substances and a polymerization inhibitor. After the continuous operation for 23 days, the low-boiling separation tower was stopped and dismantled and inspected. As a result, the weight of Dexon packing, which was the packing in the enrichment section, had increased by 0.35 g. The filling weight of the collection section is also 0.3
It had increased by 5 g. The weight of the reboiler flask also increased by 0.10 g. However, generation of a polymer that could be visually confirmed was not observed at any site.
【００２６】次に低沸分離塔の塔底より抜き出された液
を４００ｇ／Ｈｒの供給速度で製品化塔（高沸分離塔）
に供給し、製品としてのアクリル酸を回収した。製品化
塔としては、蒸留塔部が内径３０ｍｍのガラス製円筒
で、底部にはリボイラーとして２リットルのフラスコ
が、塔頂部にはコンデンサーが設置されており、コンデ
ンサーの出口は真空調整装置に接続され、蒸留塔の濃縮
部、回収部には３ｍｍのステンレス製ディクソンバッキ
ンがそれぞれ３０ｃｍ、１０ｃｍ充填されているものを
用いた。塔頂部のコンデンサーで凝縮された留出液には
フェノチアジンを約２００ｐｐｍとなるよう供給し、該
留出液の一部は製品化塔の還流液として用い、残りの留
出液は系外へ抜き出した。フラスコの加熱及び空気の吹
き込みは低沸分離塔と同様に実施しフラスコ内の液面は
フラスコよりポンプで塔底液を抜き出すことにより一定
に保った。製品化塔の運転は塔頂圧力は７５ｍｍＨｇ、
還流比１に制御し、塔頂温度は約７９℃、塔底温度は約
８８℃で１０日間継続した。Next, the liquid extracted from the bottom of the low-boiling separation tower is turned into a commercialization tower (high-boiling separation tower) at a feed rate of 400 g / Hr.
And recovered acrylic acid as a product. As a commercialization tower, the distillation column section is a glass cylinder with an inner diameter of 30 mm, a 2 liter flask as a reboiler at the bottom, a condenser at the top, and a condenser at the outlet of the condenser. The enrichment section and the recovery section of the distillation column were each filled with a 3 mm stainless steel Dickson buckin at 30 cm and 10 cm, respectively. The distillate condensed in the condenser at the top of the column is supplied with phenothiazine at a concentration of about 200 ppm, and a part of the distillate is used as a reflux for the commercialization column, and the remaining distillate is withdrawn outside the system. Was. The heating of the flask and the blowing of air were performed in the same manner as in the low-boiling separation tower, and the liquid level in the flask was kept constant by extracting the bottom liquid from the flask with a pump. Operation of the commercialization tower is performed at a top pressure of 75 mmHg,
The reflux ratio was controlled at 1, the tower top temperature was about 79 ° C., and the tower bottom temperature was about 88 ° C., which was maintained for 10 days.
【００２７】製品化塔の留出液の抜き出し量は３５０ｇ
／Ｈｒで、その組成はアクリル酸９９％以上、水０．１
％以下、酢酸３００ｐｐｍ以下及びその他アルデヒド類
１００ｐｐｍ以下であった。塔底からの抜き出し量は５
０ｇ／Ｈｒで、アクリル酸の他に高沸点物や重合禁止剤
等が含まれていた。１０日間連続運転した後、製品化塔
を停止して解体点検したところ、濃縮部の充填物である
ディクソンパッキンの重量が０．１５ｇ増加し、回収部
の充填物重量も０．１０ｇ増加していた。リボイラーで
あるフラスコの重量も０．１３ｇ増加していた。しかし
ながら、いずれの部位も目で確認できるほどの重合物の
発生は認められなかった。The amount of the distillate discharged from the commercialization tower is 350 g.
/ Hr, the composition of which is 99% or more acrylic acid and 0.1% water
% Or less, acetic acid 300 ppm or less and other aldehydes 100 ppm or less. The extraction amount from the bottom is 5
At 0 g / Hr, a high-boiling substance and a polymerization inhibitor were contained in addition to acrylic acid. After continuous operation for 10 days, the commercialization tower was stopped and dismantled and inspected. As a result, the weight of Dixon packing, which was the packing in the enrichment section, increased by 0.15 g, and the weight of the packing in the recovery section also increased by 0.10 g. Was. The weight of the reboiler flask also increased by 0.13 g. However, generation of a polymer that could be visually confirmed was not observed at any site.
【００２８】実施例２ アクリル酸含有水溶液にトリエチレンテトラミンを５０
０ｐｐｍ添加した以外は実施例１と同様に各種蒸留を実
施した。その結果を表１に示す。Example 2 Triethylenetetramine was added to an aqueous solution containing acrylic acid at a concentration of 50%.
Various distillations were carried out in the same manner as in Example 1 except that 0 ppm was added. Table 1 shows the results.
【００２９】実施例３ アクリル酸含有水溶液にジエチレントリアミンを５００
ｐｐｍ添加した以外は実施例１と同様に各種蒸留を実施
した。その結果を表１に示す。EXAMPLE 3 500 parts of diethylenetriamine were added to an aqueous solution containing acrylic acid.
Various distillations were carried out in the same manner as in Example 1 except that ppm was added. Table 1 shows the results.
【００３０】比較例１ アクリル酸含有水溶液を蒸発器を通さず、直接、共沸脱
水塔へ液状で供給した以外は実施例１と同様に各種蒸留
を実施した。その結果を表１に示す。Comparative Example 1 Various distillations were carried out in the same manner as in Example 1 except that the aqueous solution containing acrylic acid was directly supplied to the azeotropic dehydration column in liquid form without passing through the evaporator. Table 1 shows the results.
【００３１】[0031]
【表１】 [Table 1]
───────────────────────────────────────────────────── フロントページの続き (72)発明者 松下 竜二 愛媛県新居浜市惣開町５番１号 住友化学 工業株式会社内 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ryuji Matsushita 5-1, Sokai-cho, Niihama-shi, Ehime Prefecture Sumitomo Chemical Industries, Ltd.
Claims (4)
触気相酸化によって得られるアクリル酸含有水溶液を、
共沸脱水処理してアクリル酸を分離し、アクリル酸を製
造する方法に於いて、共沸脱水処理前にアクリル酸含有
水溶液を蒸発処理し、得られたアクリル酸含有蒸気を共
沸脱水処理することを特徴とするアクリル酸の製造方
法。An acrylic acid-containing aqueous solution obtained by catalytic gas-phase oxidation of propylene and / or acrolein,
In the method for producing acrylic acid by azeotropic dehydration to separate acrylic acid, the acrylic acid-containing aqueous solution is evaporated before the azeotropic dehydration, and the obtained acrylic acid-containing vapor is subjected to azeotropic dehydration. A method for producing acrylic acid.
１級および第２級のアミン類、ヒドラジン類、尿素又は
これらの塩よりなる群から選ばれた１種又は２種以上を
添加することを特徴とする請求項１記載のアクリル酸の
製造方法。2. An acrylic acid-containing aqueous solution is added with one or more selected from the group consisting of ammonia, primary and secondary amines, hydrazines, urea and salts thereof. The method for producing acrylic acid according to claim 1, wherein
ることを特徴とする請求項２記載のアクリル酸の製造方
法。3. The method for producing acrylic acid according to claim 2, wherein the amine is triethylenetetramine.
ことを特徴とする請求項２記載のアクリル酸の製造方
法。4. The method for producing acrylic acid according to claim 2, wherein the amine is diethylenetriamine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10326885A JP3031365B2 (en) | 1997-11-17 | 1998-11-17 | Method for producing acrylic acid |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9-314974 | 1997-11-17 | ||
| JP31497497 | 1997-11-17 | ||
| JP10326885A JP3031365B2 (en) | 1997-11-17 | 1998-11-17 | Method for producing acrylic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11217350A true JPH11217350A (en) | 1999-08-10 |
| JP3031365B2 JP3031365B2 (en) | 2000-04-10 |
Family
ID=26568135
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10326885A Expired - Fee Related JP3031365B2 (en) | 1997-11-17 | 1998-11-17 | Method for producing acrylic acid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3031365B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001031624A (en) * | 1999-06-28 | 2001-02-06 | Rohm & Haas Co | Preparation of (meth)acrylic acid |
| JP2001131116A (en) * | 1999-11-08 | 2001-05-15 | Nippon Shokubai Co Ltd | Method of distillation for liquid including material liable to polymerize |
| WO2001098382A1 (en) * | 2000-06-21 | 2001-12-27 | Nippon Shokubai Co., Ltd. | Process for production of water-absorbent resin |
| US6838211B2 (en) | 2001-03-07 | 2005-01-04 | Nisshinbo Industries, Inc. | Pregel compositions for polymer gel electrolytes, method of dehydrating pregel compositions, secondary cell, and electrical double-layer capacitor |
| KR100487845B1 (en) * | 2002-07-25 | 2005-05-06 | 주식회사 엘지화학 | A catalyst compositon for gaseous partial oxidation of propylene and method for preparing the same |
| JP2014508738A (en) * | 2010-12-29 | 2014-04-10 | ローム アンド ハース カンパニー | Method for reducing apparatus fouling in (meth) acrylic acid production method |
| JP2016500377A (en) * | 2012-12-19 | 2016-01-12 | ビーエーエスエフ ソシエタス・ヨーロピアＢａｓｆ Ｓｅ | Method for stabilizing polymerizable compounds |
-
1998
- 1998-11-17 JP JP10326885A patent/JP3031365B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001031624A (en) * | 1999-06-28 | 2001-02-06 | Rohm & Haas Co | Preparation of (meth)acrylic acid |
| JP2001131116A (en) * | 1999-11-08 | 2001-05-15 | Nippon Shokubai Co Ltd | Method of distillation for liquid including material liable to polymerize |
| WO2001098382A1 (en) * | 2000-06-21 | 2001-12-27 | Nippon Shokubai Co., Ltd. | Process for production of water-absorbent resin |
| US6927268B2 (en) | 2000-06-21 | 2005-08-09 | Nippon Shokubai Co., Ltd. | Production process for water-absorbent resin |
| US7238743B2 (en) | 2000-06-21 | 2007-07-03 | Nippon Shokubai Co., Ltd. | Production process for water-absorbent resin |
| US6838211B2 (en) | 2001-03-07 | 2005-01-04 | Nisshinbo Industries, Inc. | Pregel compositions for polymer gel electrolytes, method of dehydrating pregel compositions, secondary cell, and electrical double-layer capacitor |
| KR100487845B1 (en) * | 2002-07-25 | 2005-05-06 | 주식회사 엘지화학 | A catalyst compositon for gaseous partial oxidation of propylene and method for preparing the same |
| JP2014508738A (en) * | 2010-12-29 | 2014-04-10 | ローム アンド ハース カンパニー | Method for reducing apparatus fouling in (meth) acrylic acid production method |
| JP2016500377A (en) * | 2012-12-19 | 2016-01-12 | ビーエーエスエフ ソシエタス・ヨーロピアＢａｓｆ Ｓｅ | Method for stabilizing polymerizable compounds |
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|---|---|
| JP3031365B2 (en) | 2000-04-10 |
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