JPH0621104B2 - Extraction and separation of methacrylic acid - Google Patents
Extraction and separation of methacrylic acidInfo
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- JPH0621104B2 JPH0621104B2 JP4280587A JP4280587A JPH0621104B2 JP H0621104 B2 JPH0621104 B2 JP H0621104B2 JP 4280587 A JP4280587 A JP 4280587A JP 4280587 A JP4280587 A JP 4280587A JP H0621104 B2 JPH0621104 B2 JP H0621104B2
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- methacrylic acid
- extraction
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Description
【発明の詳細な説明】 (産業上の利用分野) 本発明はイソブチレン、t−ブタノール、イソブチルア
ルデヒド又はメタクロレインから気相接触酸化によりメ
タクリル酸を製造する際に得られる反応生成物の水溶液
から、ポリマー生成促進物質及び不揮発性高沸点物質を
除去し、選択的にメタクリル酸を分離回収する方法に関
するものである。The present invention relates to an aqueous solution of a reaction product obtained when methacrylic acid is produced from isobutylene, t-butanol, isobutyraldehyde or methacrolein by gas phase catalytic oxidation. The present invention relates to a method for removing a polymer production promoting substance and a non-volatile high-boiling substance and selectively separating and recovering methacrylic acid.
(従来の技術) イソブチレン、t−ブタノール、イソブチルアルデヒド
又はメタクロルレインを気相接触酸化して得られるメタ
クリル酸は、通常気相接触酸化反応によって生成した反
応生成ガスをクエンチして又は水に接触させてメタクリ
ル酸の水溶液とし、次いで蒸留でアセトン、メタクロレ
イン等の低沸点物を分離した後、水に難溶性の有機溶媒
で抽出して大部分の水や酢酸を除いた後、蒸留によって
有機溶媒とメタクリル酸を分離している。この際、メタ
クリル酸の抽出溶媒としては、芳香族類(特公昭41−
21018)、脂肪族・脂環式炭化水素類(特公昭56
−52007)、エステル類と炭化水素類との混合用媒
(特公昭49−41413、特公昭55−27894、特公昭
58−29935)、ケトン類と炭化水素類との混合溶媒
(特公昭55−34784)等を使用する方法がある。(Prior Art) Methacrylic acid obtained by vapor-phase catalytic oxidation of isobutylene, t-butanol, isobutyraldehyde, or methacrolein is usually obtained by quenching a reaction product gas produced by a vapor-phase catalytic oxidation reaction or contacting with water. To make an aqueous solution of methacrylic acid, and then separate low-boiling substances such as acetone and methacrolein by distillation, extract with a sparingly water-soluble organic solvent to remove most of water and acetic acid, and then distill organically. Separates the solvent and methacrylic acid. At this time, aromatic solvents (Japanese Patent Publication No.
21018), aliphatic / alicyclic hydrocarbons (Japanese Patent Publication No. 56)
-52007), mixed solvents of esters and hydrocarbons (Japanese Patent Publication No. 49-41413, Japanese Patent Publication No. 55-27894, Japanese Patent Publication No. 58-29935), mixed solvents of ketones and hydrocarbons (Japanese Patent Publication No. 55- 34784) and the like.
(発明が解決しようとする問題点) 気相接触酸化反応生成ガスをクエンチして又は水に接触
させて得られるメタクリル酸を主成分とする酸化生成物
水溶液中には、ポリマー生成促進物質(以下ポリマー要
因物質と略称する)や、メタクロレインやメタクリル酸
由来の種々のポリマー及び高分子タール状の不揮発性高
沸点物質(これらをまとめて以下不揮発性物質と略称す
る)が溶存しており、これら物質が要因して、メタクリ
ル酸の抽出操作時にメタクリル酸抽出能の高い抽出溶媒
を用いると抽出塔内や界面制御部に多量の不溶解固形物
質(以下スカムと略称する)が蓄積してきて、安定した
長期運転を困難にしてしまう。またこれらの溶存ポリマ
ー要因物質や不揮発発生物質の問題は次の蒸留工程にお
いても悪影響を及ぼすものである。すなわち、メタクリ
ル酸と共に抽出された溶存ポリマー要因物質及び不揮発
性物質は、蒸留塔内においてメタクリル酸のポリマー化
を促進させるとともに、蒸留の進行に伴ってこれら不揮
発性物質は蒸留塔内及び/又はリボイラー内部に蓄積又
は沈着してきて、長期間においては蒸留塔の正常な運転
を妨げる結果になる。これらの問題解決の為の有効な方
法は未だ提案されていない。(Problems to be Solved by the Invention) In the aqueous oxidation product solution containing methacrylic acid as a main component, which is obtained by quenching the gas-phase catalytic oxidation reaction product gas or contacting with water, a polymer formation promoting substance (hereinafter Polymer factor substances), various polymers derived from methacrolein and methacrylic acid, and non-volatile high-boiling substances in the form of polymer tar (collectively abbreviated as non-volatile substances below) are dissolved. Due to the substance, if an extraction solvent with a high methacrylic acid extraction capacity is used during the extraction operation of methacrylic acid, a large amount of insoluble solid substance (abbreviated as scum below) will accumulate in the extraction tower and interface control section, and it will be stable. It will make long-term driving difficult. Further, the problems of the dissolved polymer factor substance and the non-volatile generating substance have an adverse effect on the subsequent distillation step. That is, the dissolved polymer factor substance and the non-volatile substance extracted together with methacrylic acid accelerate the polymerization of methacrylic acid in the distillation column, and the non-volatile substance is accumulated in the distillation column and / or the reboiler as the distillation proceeds. It accumulates or deposits inside, resulting in impaired normal operation of the distillation column for a long period of time. No effective method for solving these problems has been proposed yet.
(問題点を解決する為の手段) 本発明者らはかかる問題を解決するために鋭意検討した
結果、気相接触酸化反応生成ガスをクエンチして又は水
に接触させて得たメタクリル酸水溶液から、特定の芳香
族炭化水素と脂肪族炭化水素各溶媒を定められた割合で
混合した混合溶媒を用いてメタクリル酸を選択的に抽出
し他方ポリマー要因物質及び不揮発性物質を抽残水相に
残すことにより、抽出工程及び蒸留工程におけるスカム
や不揮発性物質の蓄積や沈着を防止しつつ、同時に経済
性にも優れたメタクリル酸の分離回収方法を完成した。(Means for Solving Problems) As a result of intensive investigations by the present inventors to solve such problems, as a result of quenching the gas-phase catalytic oxidation reaction product gas or contacting with water, an aqueous methacrylic acid solution was obtained. , Methacrylic acid is selectively extracted by using a mixed solvent in which specific aromatic hydrocarbons and aliphatic hydrocarbons are mixed at a predetermined ratio, while the polymer factor substance and the non-volatile substance are left in the extraction residual water phase. As a result, a method for separating and recovering methacrylic acid, which is excellent in economic efficiency while preventing accumulation and deposition of scum and non-volatile substances in the extraction step and the distillation step, has been completed.
即ち、本発明は、イソブチレン、t−ブタノール、イソ
ブチルアルデヒド又はメタクロレインを気相接触酸化
し、この生成ガスをクエンチして又は水に接触させて得
られる。メタクリル酸20〜45重量%、ポリマー生成
促進物質及び不揮発性高沸点物質0.5〜5重量%含有
するメタクリル酸水溶液から、ベンゼン、トルエン、キ
シレンから選ばれた芳香族炭化水素を20〜70重量%
含む、該芳香族炭化水素とn−ヘキサン、n−ヘプタ
ン、n−オクタンから選ばれた脂肪族炭化水素との混合
溶媒を用いて、メタクリル酸を選択的に抽出することを
特徴とするメタクリル酸の抽出分離法に関する。That is, the present invention is obtained by vapor-phase catalytic oxidation of isobutylene, t-butanol, isobutyraldehyde or methacrolein, and quenching the produced gas or contacting with water. 20-70% by weight of an aromatic hydrocarbon selected from benzene, toluene and xylene from an aqueous solution of methacrylic acid containing 20-45% by weight of methacrylic acid, 0.5-5% by weight of a polymer formation promoting substance and 0.5-5% by weight of a non-volatile high boiling point substance. %
Methacrylic acid is characterized by selectively extracting methacrylic acid using a mixed solvent containing the aromatic hydrocarbon and an aliphatic hydrocarbon selected from n-hexane, n-heptane, and n-octane. Regarding the extraction and separation method of.
イソブチレン、t−ブタノール、イソブチルアルデヒド
又はメタクロレインの気相接触化反応生成ガスをクエン
チして又は水に接触させて得られるメタクエン酸水溶液
は通常メタクリル酸20〜45重量%、酢酸1〜10重
量%、アクリル酸0.1〜1重量%、メタクロレイン1
〜6重量%、アセトン0.02〜5重量%、ポリマー要因物
質及び不揮発性物質0.5〜5重量%含有している。こ
のメタクリル酸水溶液はそのまま抽出工程に送ってもよ
いが、アセトン、メタクロレイン等の低沸点物を除去し
た後抽出工程に送ってもよい。Gas phase catalytic reaction of isobutylene, t-butanol, isobutyraldehyde or methacrolein The methacrylic acid aqueous solution obtained by quenching the product gas or contacting with water is usually 20 to 45% by weight of methacrylic acid and 1 to 10% by weight of acetic acid. , Acrylic acid 0.1-1% by weight, methacrolein 1
.About.6 wt%, acetone 0.02 to 5 wt%, polymer factor substance and non-volatile substance 0.5 to 5 wt%. This methacrylic acid aqueous solution may be sent to the extraction step as it is, or may be sent to the extraction step after removing low-boiling substances such as acetone and methacrolein.
本発明においては、メタクリル酸の抽出溶液として芳香
族炭化水素と脂肪族炭化水素との混合溶媒を使用する。
この場合における芳香族炭化水素とは、ベンゼン、トル
エン、キシレンの三種から選ばれたものであり、一種だ
け用いても、又、二種以上併用してもよい。In the present invention, a mixed solvent of aromatic hydrocarbons and aliphatic hydrocarbons is used as the extraction solution of methacrylic acid.
The aromatic hydrocarbon in this case is selected from three kinds of benzene, toluene and xylene, and may be used alone or in combination of two or more kinds.
又、脂肪族炭化水素とはn−ヘキサン、n−ヘプタン、
n−オクタンの三種から選ばれたものであり一種だけ用
いても、又、二種以上併用してもよい。Also, aliphatic hydrocarbons include n-hexane, n-heptane,
It is selected from three types of n-octane, and one type may be used, or two or more types may be used in combination.
更に、これら芳香族炭化水素と脂肪族炭化水素との混合
割合は、混合溶媒中の芳香族炭化水素の濃度が20〜7
0重量%となる割合であるが、特に芳香族炭化水素を4
0〜60重量%含む混合溶媒が好ましい。Further, the mixing ratio of these aromatic hydrocarbons and aliphatic hydrocarbons is such that the concentration of aromatic hydrocarbons in the mixed solvent is 20 to 7
The ratio is 0% by weight, but especially when aromatic hydrocarbon is 4%.
A mixed solvent containing 0 to 60% by weight is preferable.
芳香族炭化水素を単独でメタクリル酸抽出溶媒に使用し
た場合には、メタクリル酸の抽出力は強く好ましいが、
同時にポリマー要因物質及び不揮発性物質の抽出力も比
較的強くなり不都合な結果となる。When an aromatic hydrocarbon is used alone as a methacrylic acid extraction solvent, the extraction power of methacrylic acid is strong and preferable,
At the same time, the extracting ability of the polymer factor substance and the non-volatile substance becomes relatively strong, resulting in an inconvenient result.
又、脂肪族炭化水素を単族で使用した場合にはメタクリ
ル酸の抽出力が極めて弱く、従つてプロセスの経済性が
すこぶる悪くなる。Further, when the aliphatic hydrocarbon is used as a single group, the extraction power of methacrylic acid is extremely weak, and therefore the economical efficiency of the process is considerably deteriorated.
しかるに本発明の如き混合溶媒を使用した場合、経済的
な溶媒使用量においてメタクリル酸の抽出率を充分高く
保つことができ、かつ種々なトラブルの原因となるポリ
マー要因物質及び不揮発性物質の抽出率を必要なまでに
低く抑えることが可能である。However, when the mixed solvent of the present invention is used, the extraction rate of methacrylic acid can be kept sufficiently high at an economical solvent usage rate, and the extraction rates of polymer factor substances and non-volatile substances that cause various troubles. Can be kept as low as necessary.
又、メタクリル酸の抽出率と抽出塔界面におけるスカム
発生量とは相関性がみられ、メタクリル酸の抽出率が高
すぎるとカラム発生量が多くなる。Further, there is a correlation between the extraction rate of methacrylic acid and the amount of scum generated at the interface of the extraction tower, and if the extraction rate of methacrylic acid is too high, the amount of column generation will increase.
この理由は、メタクリル酸抽出率が高すぎる場合には、
スカムを溶媒する成分の多くが抽出溶媒に抽出されてし
まう為に抽出塔の水相にスカムが溶解し切れずに析出
し、これが界面に蓄積してくるものと考える事ができ
る。The reason for this is that if the extraction rate of methacrylic acid is too high,
It can be considered that since most of the components that make up the scum are extracted by the extraction solvent, the scum does not dissolve in the aqueous phase of the extraction column and precipitates without being completely dissolved, which accumulates at the interface.
このスカム発生量についても、本発明の混合溶媒を使用
する事により、従来に比べて大幅に減少している。The amount of scum generated is also significantly reduced by using the mixed solvent of the present invention as compared with the conventional one.
抽出法としては回分抽出、連続向流抽出等任意な方法を
採用できるが、工業的には連続向流抽出が有利である。As the extraction method, any method such as batch extraction and continuous countercurrent extraction can be adopted, but continuous countercurrent extraction is industrially advantageous.
抽出温度は通常10〜50℃であり、常温付近で何ら差
し支えない。The extraction temperature is usually 10 to 50 ° C., and there is no problem at around normal temperature.
抽出装置としては充填塔、多孔板塔、回転円板抽出塔等
が使用できるが、これらの中では回転円板抽出塔が特に
適当と考えられる。A packed column, a perforated plate column, a rotary disc extraction column and the like can be used as the extraction device, and among them, the rotary disc extraction column is considered to be particularly suitable.
かくして得られたメタクリル酸抽出液は、ポリマー要因
物質及び不揮発性物質量が著るしく少ないものである。The thus obtained methacrylic acid extract has a remarkably small amount of polymer factor substances and non-volatile substances.
この抽出液は通常次に溶剤分離塔に送られ、塔頂から溶
媒や酢酸その他の低沸点成分を分離し、塔底から粗メタ
クリル酸が得られる。溶剤分離塔は通常高温で操作され
るため、メタクリル酸の重合防止剤が添加されるが普通
である。前記した如く、本発明の場合抽出液中のリマー
要因物質及び不揮発性物質の含量が著しく少ない為、蒸
留塔内でのポリマー生成はほとんど見られず、従って粗
メタクリル酸中の不揮発性物質濃度を充分低く保つこと
ができることになり、蒸留塔内及び/又はリボイラー内
への不揮発性物質の蓄積又は沈着の防止を可能ならしめ
るものである。This extract is then sent to a solvent separation column, where the solvent, acetic acid and other low boiling point components are separated from the column top, and crude methacrylic acid is obtained from the column bottom. Since the solvent separation column is usually operated at a high temperature, a polymerization inhibitor for methacrylic acid is usually added. As described above, in the case of the present invention, the content of the limmer factor substance and the non-volatile substance in the extract is remarkably low, so that almost no polymer formation is observed in the distillation column, and therefore the concentration of the non-volatile substance in the crude methacrylic acid is reduced. It can be kept sufficiently low, which makes it possible to prevent the accumulation or deposition of non-volatile substances in the distillation column and / or the reboiler.
得られた粗メタクリル酸は通常さらに精製されて工業用
メタクリル酸となり、又はメタノールでエステル化され
てメタクリル酸メチルとなる。The crude methacrylic acid obtained is usually further purified to industrial methacrylic acid or esterified with methanol to methyl methacrylate.
次に第1図により、本発明の一例を具体的に説明する。Next, an example of the present invention will be specifically described with reference to FIG.
イソブチレン、t−ブタノール等の気相接触酸化反応生
成ガスをクエンチして得られる、メタクロレイン等低沸
点成分を除去した後のメタクリル酸水溶液を管1にてメ
タクリル酸抽出塔2の上部に送入する。一方管3から、
本発明による混合溶媒を送入してメタクリル酸の抽出を
行なう。メタクリル酸は混合溶媒により抽出され、管4
を通り次の溶剤分離塔6に入る。A methacrylic acid aqueous solution obtained by quenching a gas-phase catalytic oxidation reaction product gas such as isobutylene or t-butanol after removing low-boiling components such as methacrolein is fed into a methacrylic acid extraction column 2 through a pipe 1. To do. On the other hand, from tube 3,
The methacrylic acid is extracted by feeding the mixed solvent according to the present invention. Methacrylic acid is extracted with a mixed solvent and pipe 4
And enters the next solvent separation tower 6.
一方、ほとんど全部のポリマー要因物質及び不揮発性物
質は水と共に管5より排出される。塔6においては、溶
媒、水、酢酸等の低沸点成分が塔頂から分離された管7
を通ってデカンター8に入る。ここで水相と油相が分離
され、水相は管9を通り抜出される。油相は一部が管1
0を通り塔6の還流として使われ、他は管3を通り塔2
の塔底部に送られて溶媒として循環使用される。On the other hand, almost all polymer factor substances and non-volatile substances are discharged from the pipe 5 together with water. In the tower 6, a pipe 7 in which low boiling point components such as solvent, water and acetic acid are separated from the top of the tower 7
Pass through Decanter 8. Here, the water phase and the oil phase are separated, and the water phase is withdrawn through the pipe 9. Oil phase is partly pipe 1
It is used as the reflux of the tower 6 through 0, and the others through the tube 3 and the tower 2
It is sent to the bottom of the column and recycled as a solvent.
塔6の塔底からはポリマー等の不揮発性物質をほとんど
含まぬ粗メタクリル酸が管11を通って回収される。From the bottom of the tower 6, crude methacrylic acid containing almost no non-volatile substance such as a polymer is recovered through a pipe 11.
(実施例) 次に実施例をあげて本発明をさらに具体的に説明する。(Example) Next, an Example is given and this invention is demonstrated more concretely.
実施例1 リン−モリブデン系の酸化触媒を用いてメタクロレイン
を空気、水蒸気の存在下で気相接触酸化し、得られた酸
化反応生成物をクエンチして回収した後、低沸点である
アルデヒド、ケトン類を蒸留で除去し、メタクリル酸3
0.0wt%、酢酸5.2wt%、アクリル酸0.4wt%、
ポリマー要因物質及び不揮発性物質2.2wt%、水6
0.5wt%、その他1.7wt%を含有するメタクリル酸
水溶液を得た。この水溶液を第1図のメタクリル酸抽出
塔に管1から3.0kg/HRの流量で送入した。メタクリ
ル酸抽出塔は内径50mm、円板86枚を有する回転円板
抽出塔であり、回転数700rpm室温で操作した。抽出
溶媒としては、トルエン50wt%、n−ヘプタン50wt
%の混合溶媒とし、流量3.0Kg/HRで管3より抽出塔
下部に送入した。定常運転における抽出液組成は、メタ
クリル酸22.5wt%、酢酸1.2wt%、アクリル酸
0.23wt%、ポリマー要因物質及び不揮発性物質0.
02wt%、その他76.05wt%でありその流量は3.
95Kg/HRであった。又、管5から排出される抽残液の
組成はメタクリル酸0.40wt%、酢酸5.2wt%、ア
クリル酸0.2wt%、ポリマー要因物質及び不揮発性物
質3.4wt%、その他90.8wt%でありその流量は
2.1Kg/HRであった。Example 1 Methacrolein was subjected to gas-phase catalytic oxidation in the presence of air and water vapor using a phosphorus-molybdenum-based oxidation catalyst, and the resulting oxidation reaction product was quenched and recovered, and then an aldehyde having a low boiling point, The ketones were removed by distillation and methacrylic acid 3
0.0 wt%, acetic acid 5.2 wt%, acrylic acid 0.4 wt%,
Polymer factor substances and non-volatile substances 2.2 wt%, water 6
An aqueous methacrylic acid solution containing 0.5 wt% and 1.7 wt% was obtained. This aqueous solution was fed into the methacrylic acid extraction column shown in FIG. 1 through pipe 1 at a flow rate of 3.0 kg / HR. The methacrylic acid extraction column is a rotating disc extraction column having an inner diameter of 50 mm and 86 discs, and operated at a rotation speed of 700 rpm at room temperature. As the extraction solvent, toluene 50 wt%, n-heptane 50 wt
% Mixed solvent, and the mixture was fed into the lower part of the extraction column through the pipe 3 at a flow rate of 3.0 kg / HR. The composition of the extract in steady operation was 22.5 wt% of methacrylic acid, 1.2 wt% of acetic acid, 0.23 wt% of acrylic acid, polymer factor substances and non-volatile substances.
02 wt% and others 76.05 wt% and the flow rate is 3.
It was 95 Kg / HR. The composition of the raffinate discharged from the pipe 5 is 0.40 wt% methacrylic acid, 5.2 wt% acetic acid, 0.2 wt% acrylic acid, 3.4 wt% polymer factor substances and non-volatile substances, and 90.8 wt% for others. %, And the flow rate was 2.1 Kg / HR.
この場合メタクリル酸の抽出率は99.1%で、実用上
満足できる値であり、又、ポリマー要因物質及び不揮発
性物質の抽質率は1.1%と充分低い値が得られた。得
られた抽出液は管4を通り溶剤分離塔6に送られた。In this case, the extraction rate of methacrylic acid was 99.1%, which was a practically satisfactory value, and the extraction rate of the polymer factor substance and the non-volatile substance was 1.1%, which was a sufficiently low value. The obtained extract was sent to the solvent separation tower 6 through the pipe 4.
溶剤分離塔は内径72mで、グッドロールパツキング
2.4mの充填塔を使用した。操作圧力50toorで還流
比1.0で運転した。溶媒その他の低沸点成分は塔頂か
ら回収され管3にて超出塔2にリサイクルした。塔底か
らは粗メタクリル酸が管11から得られ、その組成はメ
タクリル酸98.75wt%、アクリル酸0.9wt%、ポリマ
ー要因物質及び不揮発性物質0.15wt%、その他0.
2wt%であった。As the solvent separation column, a packed column having an inner diameter of 72 m and a Goodroll packing 2.4 m was used. It was operated at a reflux ratio of 1.0 at an operating pressure of 50 toor. The solvent and other low-boiling components were recovered from the top of the column and recycled to the super-extraction column 2 through the pipe 3. From the bottom of the column, crude methacrylic acid was obtained from the tube 11, and its composition was 98.75% by weight of methacrylic acid, 0.9% by weight of acrylic acid, 0.15% by weight of polymer factor substances and non-volatile substances, and others.
It was 2 wt%.
この液は透明であり、ポリマー等の固形微粒子は全く見
られず、すこぶる良好な液性であった。抽出塔と蒸留塔
の組合せ運転は5日間実施したが、運転後における抽出
塔界面のスカムは2〜3mm厚さで少なく、又蒸留塔リボ
イラー内面へのポリマー等の固形物付着による汚れはみ
られなかった。This liquid was transparent, solid fine particles such as polymer were not observed at all, and it was a very good liquid property. The combined operation of the extraction column and the distillation column was carried out for 5 days, but the scum at the interface of the extraction column after the operation was small with a thickness of 2 to 3 mm, and stains due to the adherence of solid substances such as polymers to the inner surface of the distillation column reboiler were observed. There wasn't.
実施例2 抽出溶媒としてベンゼン50wt%、n−ヘブタン50wt
%の混合溶媒を用い、その他は実施例1と全く同じ条件
で抽出塔と溶剤分離塔の運転を実施した。得られた抽出
液組成はメタクリル酸22.6wt%、酢酸1.3wt%、アク
リル酸0.25wt%、ポリマー要因物質及び不揮発性物
質0.03wt%、その他75.8wt%でありその流量は
3.95Kg/HRであった。油残液組成はメタクリル酸
0.35wt%、ポリマー要因物質及び不揮発性物質3.
4wt%、その他96.25wt%でありその流量は2.0
5Kg/HRであった。この場合メタクリル酸の抽出率は99.
2%、ポリマー要因物質及び不揮発性物質の抽出率は
1.7%で、各々充分満足できる値であった。Example 2 Benzene 50 wt% and n-heptane 50 wt as extraction solvents
% Of the mixed solvent was used, and the extraction column and the solvent separation column were operated under exactly the same conditions as in Example 1 except for the above. The composition of the obtained extract solution was 22.6 wt% methacrylic acid, 1.3 wt% acetic acid, 0.25 wt% acrylic acid, 0.03 wt% polymer factor substances and non-volatile substances, and 75.8 wt% other, and the flow rate was 3. It was 95 Kg / HR. Oil residual liquid composition is methacrylic acid 0.35 wt%, polymer factor substances and non-volatile substances 3.
4wt%, others 96.25wt% and its flow rate is 2.0
It was 5 Kg / HR. In this case, the extraction rate of methacrylic acid is 99.
2%, the extraction rate of the polymer factor substance and the non-volatile substance was 1.7%, which were sufficiently satisfactory values.
抽出液は引続き溶剤分離塔に送られ、塔底からメタクリ
ル酸98.7wt%、アクリル酸0.9wt%、ポリマー要
因物質及び不揮発性物質0.2wt%、その他0.2wt%
の粗メタクリル酸が得られた。液性は実施例1と同様で
すこぶる良好であった。The extract is continuously sent to the solvent separation tower, and from the bottom of the tower, methacrylic acid 98.7 wt%, acrylic acid 0.9 wt%, polymer factor substances and non-volatile substances 0.2 wt%, other 0.2 wt%
Of crude methacrylic acid was obtained. The liquid properties were similar to those in Example 1 and were very good.
5日間運転後、抽出塔界面でのスカム厚さは2〜3mmで
あり何ら支障なく操作できた。After operating for 5 days, the scum thickness at the extraction tower interface was 2 to 3 mm, and the operation could be performed without any trouble.
又、蒸留塔リボイラー内面及び塔内にはポリマー等固形
物の付着はみられず満足した運転が実施できた。In addition, solid matters such as polymers were not adhered to the inner surface of the distillation tower reboiler and the inside of the tower, and the operation was satisfactory.
実施例3 抽出溶媒としてキシレン50wt%、n−ヘキサン50wt
%の混合溶媒を用いた以外は実施例1と同様にして運転
を実施したところ、実施例1の同様の満足した結果が得
られた。Example 3 Xylene 50 wt% and n-hexane 50 wt% as extraction solvents
When the operation was performed in the same manner as in Example 1 except that the mixed solvent of 1% was used, the same satisfactory result as in Example 1 was obtained.
実施例4 抽出溶媒としてトルエン50wt%、n−オクタン50wt
%の混合溶媒を用いた以外は実施例1と同様にして運転
を実施したところ、実施例1と同様の満足した結果が得
られた。Example 4 Toluene 50 wt% and n-octane 50 wt% as extraction solvents
When the operation was performed in the same manner as in Example 1 except that the mixed solvent of 1% was used, the same satisfactory result as in Example 1 was obtained.
実施例5 メタクロレインの気相接触酸化生成ガスをクエンチして
得たメタクリル酸水溶液の代りにイソブチレン、t−ブ
タノール又はイソブチルアルデヒドの気相接触酸化をク
エンチして得たメタクリル酸水溶液を用い、その他は実
施例1と同様にして運転を実施したところ、いずれの場
合も実施例1と同様に満足した結果が得られた。Example 5 Vapor Phase Catalytic Oxidation of Methacrolein An aqueous solution of methacrylic acid obtained by quenching the vapor phase catalytic oxidation of isobutylene, t-butanol or isobutyraldehyde was used in place of the aqueous solution of methacrylic acid obtained by quenching the product gas. When the operation was carried out in the same manner as in Example 1, satisfactory results were obtained as in Example 1 in all cases.
比較例1 抽出溶媒としてトルエンを用い、その他は実施例1と全
く同じ条件で抽出塔と溶剤分離塔の運転を実施した。得
られた抽出液の組成はメタクリル酸22.6wt%、酢酸
1.5wt%、アクリル酸0.3wt%、ポリマー要因物質
及び不揮発性物執0.15wt%、その他75.45wt%
でありその流量は3.97Kg/HRであった。抽残液の組成は
メタクリル酸0.25wt%、ポリマー要因物質及び不揮
発性物質3.2wt%、その他96.55wt%であり、そ
の流量は2.0Kg/HRであった。Comparative Example 1 Toluene was used as an extraction solvent, and the extraction column and the solvent separation column were operated under exactly the same conditions as in Example 1. The composition of the resulting extract is 22.6 wt% methacrylic acid, 1.5 wt% acetic acid, 0.3 wt% acrylic acid, 0.15 wt% polymer and non-volatile matter, and 75.45 wt% other.
And the flow rate was 3.97 Kg / HR. The composition of the raffinate was 0.25 wt% of methacrylic acid, 3.2 wt% of the polymer factor substance and non-volatile substance, and 96.55 wt% of others, and the flow rate was 2.0 Kg / HR.
この場合メタクリル酸の抽出率は99.5%と良好であ
ったが、ポリマー要因物質及び不揮発性物質の抽出率は
8.5%と高すぎる値を示した。抽出塔界面のスカムも
多く、小粒のスカムが時々抽出液に混って同伴すること
があった。この抽出液は引続いて溶剤分離塔に送られ、
塔底からメタクリル酸97.6wt%、アクリル酸1.
3wt%、ポリマー要因物質及び不揮発性物質0.85wt
%、その他0.25wt%の組成を有する粗メタクリル酸
を得た。In this case, the extraction rate of methacrylic acid was as good as 99.5%, but the extraction rates of the polymer factor substance and the non-volatile substance were too high at 8.5%. There were many scums at the interface of the extraction tower, and small-sized scums sometimes mixed with the extraction liquid and accompanied. This extract is subsequently sent to the solvent separation tower,
Methacrylic acid 97.6 wt%, acrylic acid 1.
3wt%, polymer factor substances and non-volatile substances 0.85wt
%, And other crude methacrylic acid having a composition of 0.25 wt% was obtained.
この粗メタクリル酸中には微量の白色微粒子が存在して
いた。運転は5日間行ったが、抽出塔界面のスカム層の
厚さは5〜10mmであり、実施例1よりかなり多かっ
た。又蒸留塔リボイラー内面にはうすい膜状の白色付着
物(メタクリル酸のポリマーが主成分)がみられ、その
為に伝熱能力を低下させていた。A small amount of white fine particles were present in this crude methacrylic acid. The operation was carried out for 5 days, but the thickness of the scum layer at the interface of the extraction tower was 5 to 10 mm, which was considerably larger than that in Example 1. In addition, a thin film-like white deposit (polymer of methacrylic acid was the main component) was found on the inner surface of the distillation column reboiler, which reduced the heat transfer ability.
比較例2 抽出溶媒としてn−ヘプタンを用い、その他は実施例1
と全く同じ条件で運転を実施した。Comparative Example 2 n-heptane was used as the extraction solvent, and the others were used in Example 1.
The operation was carried out under exactly the same conditions as above.
得られた抽出液の組成はメタクリル酸22.1wt%、酢
酸0.8wt%、アクリル酸0.15wt%、ポリマー要因
物質及び不揮発性物質0.01wt%、その他76.94
wt%でありその流量は3.90Kg/HRであった。抽残液
の組成はメタクリル酸1.70wt%、ポリマー要因物質
及び不揮発性物質3.30wt%、その他95.0wt%で
ありその流量は2.15Kg/HRであった。この場合ポリ
マー要因物質及び不揮発性物質の抽出率は0.5%と低
く好ましかったが、主成分であるメタクリル酸の抽出率
が96.0%と非常に低すぎて、このままでは実用にな
らない事がわかった。The composition of the obtained extract was 22.1 wt% methacrylic acid, 0.8 wt% acetic acid, 0.15 wt% acrylic acid, 0.01 wt% polymer factor substances and non-volatile substances, and other 76.94%.
It was wt% and the flow rate was 3.90 Kg / HR. The composition of the raffinate was 1.70 wt% of methacrylic acid, 3.30 wt% of polymer factor substances and non-volatile substances, and 95.0 wt% of others, and the flow rate was 2.15 Kg / HR. In this case, the extraction ratio of the polymer-causing substance and the non-volatile substance was low at 0.5%, which was preferable, but the extraction ratio of methacrylic acid as the main component was 96.0%, which was too low. I knew it wouldn't happen.
次にメタクリル酸の抽出率向上の為、n−ヘプタンの流
量のみ6.0Kg/HRと2倍にし、他はそのままとして運
転した。得られた抽出液の組成はメタクリル酸12.8
wt%、酢酸0.56wt%、アクリル酸0.1wt%、ポリ
マー要因物質及び不揮発性物質0.01wt%、その他8
6.53wt%でありその流量は6.94Kg/HRであっ
た。Next, in order to improve the extraction rate of methacrylic acid, only the flow rate of n-heptane was doubled to 6.0 kg / HR, and the others were operated as they were. The composition of the obtained extract was 12.8 methacrylic acid.
wt%, acetic acid 0.56 wt%, acrylic acid 0.1 wt%, polymer factor substances and non-volatile substances 0.01 wt%, others 8
The flow rate was 6.53 wt% and the flow rate was 6.94 Kg / HR.
抽残液の組成はメタクリル酸0.43wt%、ポリマー要
因物質及び不揮発性物質3.2wt%、その他96.37
%でありその流量は2.1Kg/Hであった。この場合メタ
クリル酸の抽出率は99.0%、ポリマー要因物質及び
不揮発性物質の抽出率は1.0%であり満足できるもの
であるが、抽出溶媒の使用量が2倍と多く、やはり実用
性に欠けることが証明された。The composition of the raffinate is 0.43 wt% methacrylic acid, 3.2 wt% polymer factor substances and non-volatile substances, and 96.37 other.
%, And the flow rate was 2.1 Kg / H. In this case, the extraction rate of methacrylic acid is 99.0%, and the extraction rate of polymer factor substances and non-volatile substances is 1.0%, which is satisfactory, but the amount of extraction solvent used is twice as large, which is also practical. It was proved to lack sex.
(発明の効果) 以上の如く、本発明による混合溶媒を用いてメタクリル
酸水溶液よりメタクリル酸の抽出を行なえば、メタクリ
ル酸を高選択的かつ経済的に抽出が可能になり、さらに
抽出、蒸留各工程においてポリマー等不揮発性物質の蓄
積や沈着を防止できて長期安定運転が可能となる。(Effects of the Invention) As described above, when methacrylic acid is extracted from an aqueous methacrylic acid solution using the mixed solvent according to the present invention, methacrylic acid can be highly selectively and economically extracted, and further extraction and distillation can be performed. In the process, accumulation and deposition of non-volatile substances such as polymers can be prevented, and stable operation for a long period of time becomes possible.
第1図は本発明方法の一実施態様を示すフローシートで
ある。 2……メタクリル酸抽出塔 6……溶剤分離塔 8……デカンター(相分離器)FIG. 1 is a flow sheet showing one embodiment of the method of the present invention. 2 ... Methacrylic acid extraction tower 6 ... Solvent separation tower 8 ... Decanter (phase separator)
Claims (1)
ルアルデヒド又はメタクロレインを気相接触酸化し、こ
の生成ガスをクエンチして又は水に接触させて得られ
る、メタクリル酸20〜45重量%、ポリマー生成促進
物質及び不揮発性高沸点物質から、0.5〜5重量%含
有するメタクリル酸水溶液から、ベンゼン、トルエン、
キシレンから選ばれた芳香族炭化水素を20〜70重量
%含む、該芳香族炭化水素とn−ヘキサン、n−ヘプタ
ン、n−オクタンから選ばれた脂肪族炭化水素との混合
溶媒を用いて、メタクリル酸を選択的に抽出することを
特徴とするメタクリル酸の抽出分離法。1. Methacrylic acid 20 to 45% by weight, which is obtained by subjecting isobutylene, t-butanol, isobutyraldehyde or methacrolein to vapor-phase catalytic oxidation and quenching the produced gas or contacting with water to accelerate polymer production. Substances and non-volatile high-boiling substances, methacrylic acid aqueous solutions containing 0.5 to 5% by weight, benzene, toluene,
Using 20 to 70% by weight of an aromatic hydrocarbon selected from xylene, a mixed solvent of the aromatic hydrocarbon and an aliphatic hydrocarbon selected from n-hexane, n-heptane, and n-octane, A method for extracting and separating methacrylic acid, which comprises selectively extracting methacrylic acid.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4280587A JPH0621104B2 (en) | 1987-02-27 | 1987-02-27 | Extraction and separation of methacrylic acid |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4280587A JPH0621104B2 (en) | 1987-02-27 | 1987-02-27 | Extraction and separation of methacrylic acid |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS63211249A JPS63211249A (en) | 1988-09-02 |
JPH0621104B2 true JPH0621104B2 (en) | 1994-03-23 |
Family
ID=12646177
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4280587A Expired - Lifetime JPH0621104B2 (en) | 1987-02-27 | 1987-02-27 | Extraction and separation of methacrylic acid |
Country Status (1)
Country | Link |
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JP (1) | JPH0621104B2 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4995715B2 (en) | 2005-12-26 | 2012-08-08 | 三菱レイヨン株式会社 | Extraction method of methacrylic acid |
JP5504668B2 (en) * | 2008-03-31 | 2014-05-28 | 三菱化学株式会社 | Method for producing (meth) acrylic acid |
JP5386847B2 (en) * | 2008-03-31 | 2014-01-15 | 三菱化学株式会社 | Acrylic acid production method |
-
1987
- 1987-02-27 JP JP4280587A patent/JPH0621104B2/en not_active Expired - Lifetime
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