JPH0764776B2 - How to absorb methacrolein - Google Patents
How to absorb methacroleinInfo
- Publication number
- JPH0764776B2 JPH0764776B2 JP6721088A JP6721088A JPH0764776B2 JP H0764776 B2 JPH0764776 B2 JP H0764776B2 JP 6721088 A JP6721088 A JP 6721088A JP 6721088 A JP6721088 A JP 6721088A JP H0764776 B2 JPH0764776 B2 JP H0764776B2
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- JP
- Japan
- Prior art keywords
- methacrolein
- tower
- methacrylic acid
- absorption tower
- aqueous solution
- 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.)
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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、メタクロレインの吸収方法に関し、詳しく
は、メタクロレインの吸収溶剤として、冷却することに
より晶析するテレフタル酸等の高沸点物質が除去され、
かつメタクロレインを含まない系内メタクリル酸水溶液
を用いる方法に関する。TECHNICAL FIELD The present invention relates to a method for absorbing methacrolein, and more specifically, as a solvent for absorbing methacrolein, a high-boiling substance such as terephthalic acid that crystallizes upon cooling is used. Removed,
In addition, the present invention relates to a method using an in-system methacrylic acid aqueous solution containing no methacrolein.
イソブチレン、第３級ブタノール、イソブチルアルデヒ
ドまたはメタクロレインを、水蒸気の存在下に分子状酸
素で一段または二段の反応で接触酸化することにより、
目的物であるメタクリル酸の他に、メタクロレイン、酢
酸、一酸化炭素、二酸化炭素、水、酸素、窒素等を含有
する反応生成ガスが得られる。反応生成ガスは、通常、
急冷されてメタクリル酸、水等を凝縮し、大部分のメタ
クロレインと窒素、酸素等の非凝縮性ガスが塔頂より分
離される。窒素、酸素等の非凝縮性ガスとメタクリル酸
製造の原料としても用いられるメタクロレインとを効率
良く分離回収する方法としては、溶剤を用いてメタクロ
レインを吸収し、吸収液を蒸留分離してメタクロレイン
を回収する方法がある。このような吸収溶剤として、水
（特開昭53−144515）、酢酸（特開昭54−48706）、メ
タクロレインの除去されたメタクリル酸水溶液（特開昭
54−52027）などを用いる方法が知られている。By catalytically oxidizing isobutylene, tertiary butanol, isobutyraldehyde or methacrolein with molecular oxygen in the presence of steam in a one-step or two-step reaction,
In addition to the target product, methacrylic acid, a reaction product gas containing methacrolein, acetic acid, carbon monoxide, carbon dioxide, water, oxygen, nitrogen and the like can be obtained. The reaction product gas is usually
It is rapidly cooled to condense methacrylic acid and water, and most of methacrolein and non-condensable gases such as nitrogen and oxygen are separated from the top of the column. As a method for efficiently separating and recovering non-condensable gases such as nitrogen and oxygen and methacrolein which is also used as a raw material for the production of methacrylic acid, methacrolein is absorbed by using a solvent, and the absorbing solution is separated by distillation to obtain methacrolein. There is a method to collect rain. As such an absorbing solvent, water (JP-A-53-144515), acetic acid (JP-A-54-48706), and an aqueous methacrylic acid solution from which methacrolein has been removed (JP-A-JP-A-54-48706).
54-52027) and the like are known.
反応生成ガスの急冷工程で凝縮しないメタクロレインを
吸収する溶剤としてメタクロレインの除去されたメタク
リル酸水溶液を用いる方法は、あらたに系外から吸収溶
剤を導入することなく、吸収工程で得られる吸収液から
のメタクロレインの回収および急冷工程で凝縮したメタ
クロレインの回収のような二系統のメタクロレインの回
収を必要とせず、一つの蒸留塔で行なえることから有利
な方法と言える。しかしながら、メタクロレインの吸収
は、一般に低温ほど効率が良いため、通常は低温で運転
される。したがって副生したテレフタル酸等の高沸点物
質がメタクリル酸水溶液を冷却することにより析出し、
更には、これら析出物の堆積により系内閉塞等の問題が
あった。The method of using an aqueous solution of methacrylic acid from which methacrolein has been removed as a solvent that absorbs methacrolein that does not condense in the quenching step of the reaction product gas is a new absorption liquid obtained in the absorption step without introducing an absorption solvent from outside the system. It is an advantageous method because it can be carried out in one distillation column without the need for recovery of methacrolein from two systems such as recovery of methacrolein from methacrolein and recovery of methacrolein condensed in the quenching step. However, since the absorption of methacrolein is generally more efficient at lower temperatures, it is usually operated at lower temperatures. Therefore, high boiling point substances such as terephthalic acid, which are a by-product, are deposited by cooling the methacrylic acid aqueous solution,
Further, there is a problem such as clogging of the system due to the accumulation of these precipitates.
本発明者は、上記の課題を解決するため鋭意検討した結
果、本発明を完成するに至ったものである。すなわち、
本発明のメタクロレインの吸収方法は、イソブチレン、
第３級ブタノール、イソブチルアルデヒドまたはメタク
ロレインを酸化触媒の存在下に分子状酸素を含有するガ
スと気相反応させて得られる反応生成ガスからメタクロ
レインを回収する方法において、該反応生成ガスを予め
凝縮させた凝縮液の一部と10〜75℃の温度で向流接触せ
しめる急冷塔に供給して該反応生成ガス中のメタクリル
酸と水とを凝縮分離し、一方、大部分のメタクロレイン
を含む非凝縮性ガスを５〜30℃で操作されるメタクロレ
イン吸収塔塔底部に供給し、吸収塔塔頂部よりメタクリ
ル酸水溶液を供給してメタクロレインを吸収分離し、メ
タクロレイン以外の非凝縮性ガスを吸収塔塔頂より放出
し、吸収塔塔底より缶出するメタクロレインを含むメタ
クリル酸水溶液を、急冷塔より缶出した凝縮液の一部を
メタクロレイン吸収塔の塔頂ガス温度よりも低い温度ま
で冷却して生成する固形物を固形物分離器で除去した急
冷塔凝縮液と別々にまたは合流して、塔底温度が100℃
以下で操作されるメタクロレイン回収塔中段に供給し、
回収塔塔頂よりメタクロレインを分離回収し、回収塔塔
底よりメタクロレインの分離されたメタクリル酸水溶液
の一部をメタクロレインの吸収剤としてメタクロレイン
吸収塔塔頂部へ循環することを特徴とするものである。The present inventor has completed the present invention as a result of extensive studies to solve the above problems. That is,
The method for absorbing methacrolein of the present invention is isobutylene,
In a method of recovering methacrolein from a reaction product gas obtained by reacting a tertiary butanol, isobutyraldehyde or methacrolein with a gas containing molecular oxygen in the presence of an oxidation catalyst, the reaction product gas is previously collected. A part of the condensed condensate is supplied to a quenching tower which is brought into countercurrent contact at a temperature of 10 to 75 ° C. to condense and separate methacrylic acid and water in the reaction product gas, while most of methacrolein is removed. Non-condensable gas other than methacrolein is absorbed by supplying non-condensable gas containing it to the bottom of methacrolein absorption tower operated at 5 to 30 ° C, and supplying methacrylic acid aqueous solution from the top of the absorption tower to absorb and separate methacrolein. The methacrylic acid solution containing methacrolein discharged from the top of the absorption tower and discharged from the bottom of the absorption tower absorbs part of the condensate discharged from the quench tower. Top gas temperature solids generated by cooling to a temperature lower than the solids removed quench tower condensate and separately or merged to with separator, the bottom temperature is 100 ° C.
Supply to the middle stage of the methacrolein recovery tower operated below,
Characteristically, methacrolein is separated and recovered from the top of the recovery tower, and a part of the methacrylic acid aqueous solution from which the methacrolein is separated is circulated from the bottom of the recovery tower to the top of the methacrolein absorption tower as the methacrolein absorbent. It is a thing.
本発明の急冷塔では、反応生成ガスと予め凝縮させたメ
タクリル酸水溶液の一部とが向流接触し、大部分のメタ
クロレインを含む非凝縮性ガスとメタクリル酸、水とに
分離出来る10〜75℃の温度に設定され、大部分のメタク
ロレインを含む非凝縮性ガスは急冷塔塔頂部より次のメ
タクロレイン吸収塔塔底部に供給される。急冷塔におけ
る向流接触温度が10℃に満たない場合は、凝縮させたメ
タクリル酸を過度に冷却しなければならず、工業的に好
ましくなく、一方、75℃を越える場合は、メタクリル酸
および水等の凝縮率が低下し好ましくない。In the quenching tower of the present invention, the reaction product gas and a part of the previously condensed methacrylic acid aqueous solution are in countercurrent contact with each other, and the non-condensable gas containing most of methacrolein can be separated into methacrylic acid and water. The temperature is set to 75 ° C., and the non-condensable gas containing most of methacrolein is supplied from the top of the quenching tower to the bottom of the next methacrolein absorption tower. When the countercurrent contact temperature in the quenching tower is less than 10 ° C, the condensed methacrylic acid must be excessively cooled, which is not industrially preferable. On the other hand, when it exceeds 75 ° C, methacrylic acid and water are not preferable. It is not preferable because the condensation rate of the like decreases.
操作する塔数としては、１塔または２塔以上必要に応じ
決定すれば良いが、操作温度を急冷工程の最終塔の塔頂
ガス温度が10℃以上にならないように操作することが好
ましい。向流接触方式としては、充填塔、スプレー塔、
多孔板塔など通常行われている形式であれば何れでも良
い。The number of towers to be operated may be determined according to need, one tower or two or more towers, but it is preferable to operate so that the temperature of the top gas of the final tower in the quenching step does not exceed 10 ° C. Countercurrent contact methods include packed towers, spray towers,
Any conventional method such as a perforated plate tower may be used.
メタクロレイン吸収塔塔底部に送られた急冷塔で凝縮し
ない大部分のメタクロレインを含む非凝縮性ガスは、後
の工程であるメタクロレイン回収塔においてメタクロレ
インの除去されたメタクリル酸水溶液と向流接触し、メ
タクロレインが吸収され、吸収塔塔頂よりメタクロレイ
ン以外の非凝縮性ガス、例えば、窒素、酸素、一酸化炭
素及び二酸化炭素等が放出される。吸収塔の形式は、充
填塔、多孔板塔、泡錘塔、など通常用いられている形式
のものであれば制約はない。操作温度は該塔頂ガス温度
が５〜30℃の範囲になるように操作される。30℃を越え
るとメタクリル酸水溶液によるメタクロレインの吸収効
率が低下し、５℃に満たない場合は、メタクリル酸水溶
液を過度に冷却しなければならず、工業的に好ましくな
い。The non-condensable gas containing most of methacrolein that does not condense in the quench tower sent to the bottom of the methacrolein absorption tower is countercurrent to the methacrylic acid aqueous solution from which methacrolein has been removed in the later step of the methacrolein recovery tower. Upon contact, methacrolein is absorbed, and non-condensable gases other than methacrolein, such as nitrogen, oxygen, carbon monoxide and carbon dioxide, are released from the top of the absorption tower. There is no limitation on the type of the absorption tower as long as it is a commonly used type such as a packed tower, a perforated plate tower, and a bubble column tower. The operating temperature is such that the gas temperature at the top of the column is in the range of 5 to 30 ° C. If it exceeds 30 ° C, the absorption efficiency of methacrolein by the aqueous methacrylic acid solution decreases, and if it is less than 5 ° C, the aqueous methacrylic acid solution must be excessively cooled, which is not industrially preferable.
メタクロレイン吸収塔塔頂部へ供給するメタクリル酸水
溶液のメタクリル酸濃度は、酸化反応における反応条件
により異なるが、５重量％以上、好ましくは10重量％以
上である。また、供給するメタクリル酸水溶液量は、通
常、該吸収塔供給ガスのモル流量に対して、メタクリル
酸水溶液のモル流量を0.3〜10倍、好ましくは、１〜５
倍の範とする。The methacrylic acid concentration of the aqueous methacrylic acid solution supplied to the top of the methacrolein absorption tower is 5% by weight or more, preferably 10% by weight or more, though it varies depending on the reaction conditions in the oxidation reaction. The amount of the aqueous methacrylic acid solution to be supplied is usually 0.3 to 10 times, preferably 1 to 5 times the molar flow rate of the aqueous methacrylic acid solution with respect to the molar flow rate of the gas supplied to the absorption tower.
Double the standard.
この様にしてメタクロレイン吸収塔塔底部より得られた
メタクロレインを吸収したメタクリル酸水溶液は、場合
により急冷塔で凝縮したメタクロレインを含むメタクリ
ル酸水溶液の一部と共に、該吸収塔塔頂ガス温度まで冷
却することにより晶析したメタクリル酸水溶液中の高沸
点物質、例えば、テレフタル酸等を固形物分離器で除去
したメタクロレインを含むメタクリル酸水溶液と合流
し、或は別々に、塔底温度が100℃以下で好ましくは50
〜95℃で操作されるメタクロレイン回収塔中段に供給さ
れ、塔頂部からメタクロレインを分離回収し、メタクリ
ル酸製造用原料として反応器に循環使用してもよい。塔
底温度が100℃以上になるとメタクロレインおよびメタ
クリル酸の重合が起こり採用できない。回収塔塔底部よ
り得られるメタクロレインの除去されたメタクリル酸水
溶液の一部をメタクロレイン吸収塔塔頂部にメタクロレ
イン吸収溶剤として供給し、残りはメタクリル酸水溶液
としてメタクリル酸精製工程に送られる。メタクリル酸
水溶液中の高沸点物質の除去は、急冷塔缶出液およびメ
タクロレイン回収塔缶出液の何れにおいても除去可能で
あるが、晶析物の堆積による系内の詰まり、更には、閉
塞による予防を行う意味からも処理工程の初期段階で除
去することが好ましく、急冷塔缶出液から高沸点物質を
除去する方が更に好ましい。晶析温度を変えて二段また
は三段とプロセスの要所に設置することも出来る。以上
のように各段階で充分除去出来ればメタクロレイン回収
塔缶出液の一部を、そのままメタクロレインの吸収に用
いるのが良い。The aqueous solution of methacrylic acid having absorbed methacrolein obtained from the bottom of the methacrolein absorption tower in this manner, together with a part of the aqueous methacrylic acid solution containing methacrolein condensed in the quench tower, the gas temperature at the top of the absorption tower. By cooling to a high boiling point substance in the methacrylic acid aqueous solution that has been crystallized, for example, methacrylic acid-containing methacrylic acid aqueous solution obtained by removing terephthalic acid and the like with a solids separator is joined, or separately, the tower bottom temperature 50 ° C or below, preferably 50
It may be supplied to the middle stage of the methacrolein recovery column operated at ˜95 ° C., methacrolein may be separated and recovered from the top of the column, and may be recycled to the reactor as a raw material for methacrylic acid production. When the tower bottom temperature is 100 ° C or higher, methacrolein and methacrylic acid are polymerized and cannot be used. A part of the methacrylic acid aqueous solution from which the methacrolein has been removed, which is obtained from the bottom of the recovery tower, is supplied to the top of the methacrolein absorption tower as a methacrolein absorbing solvent, and the rest is sent to the methacrylic acid refining step as a methacrylic acid aqueous solution. The high boiling point substance in the methacrylic acid aqueous solution can be removed by both the bottom liquid of the quenching tower and the bottom liquid of the methacrolein recovery tower, but clogging of the system due to the deposition of crystallization products, and further clogging It is preferable to remove it in the early stage of the treatment process also from the viewpoint of prevention by the method, and it is more preferable to remove the high boiling point substance from the quench tower bottoms. It is also possible to change the crystallization temperature and install it in two or three stages, which are important points in the process. If the methacrolein recovery tower can be partially removed as described above, it is preferable to use a part of the methacrolein recovery tower bottom as it is for the absorption of methacrolein.
本発明の固形物分離器としては、例えば、充填式フィル
ター、沈降槽など効率的に固形物が除去できるものであ
れば特に制限はない。The solids separator of the present invention is not particularly limited as long as it can efficiently remove solids such as a filling filter and a sedimentation tank.
更に、図面を用いて詳細に説明する。 Furthermore, it demonstrates in detail using drawing.
第１図は、本発明のメタクロレイン吸収方法の一実施例
によるフロー図である。FIG. 1 is a flow chart according to an embodiment of the methacrolein absorption method of the present invention.
イソブチレン、第３級ブタノール、イソブチルアルデヒ
ドまたはメタクロレインを酸化触媒の存在下に分子状酸
素を含有するガスと気相反応させて得られた反応生成ガ
スをライン１より急冷塔Ａに供給し、予め凝縮した凝縮
液の一部と熱交換器Ｅを介し、ライン４を通じ循環して
向流接触せしめた。メタクリル酸、水等が凝縮されメタ
クロレインを含むメタクリル酸水溶液は、ライン２を経
て熱交換器Ｆに送られ、メタクロレイン吸収塔Ｂ塔頂部
ガス温度以下に冷却されることにより析出したメタクリ
ル酸中の高沸点物質は固形物分離器Ｄにおいて除去され
ライン５を経てメタクロレイン回収塔Ｃに供給される。
一方、分離された大部分のメタクロレインを含む非凝縮
性ガスは、急冷塔Ａの塔頂部からライン３を通じメタク
ロレイン吸収塔Ｂの塔底部へ供給され、メタクロレイン
回収塔Ｃの塔底部より得られるメタクロレインの除去さ
れたメタクリル酸水溶液の一部とメタクロレイン吸収剤
としてライン12を通じ、メタクロレイン吸収塔Ｂの塔頂
部に送られて向流接触される。メタクロレイン吸収塔Ｂ
の塔頂ライン７からメタクロレインの除去された非凝縮
性ガスが放出され、メタクロレイン吸収塔Ｂの塔底部か
らはメタクロレイン含有メタクリル酸水溶液がライン６
を経てライン５より送られてきた前述の高沸点物質等の
除去されたメタクロレインを含むメタクリル酸水溶液と
合流し、ライン８を経てメタクロレイン回収塔Ｃの中段
部へ供給され、メタクロレイン回収塔Ｃの塔頂部からラ
イン９を通じメタクロレインを回収し、または、そのま
まメタクリル酸製造用原料として反応器へ循環される。
また、メタクロレイン回収塔Ｃの塔底部より得られたメ
タクロレインの除去されたメタクリル酸水溶液は、前述
の様に一部はライン12を通じメタクロレイン吸収塔Ｂ
に、残りはライン11を通じて次のメタクリル酸精製工程
に送られる。A reaction product gas obtained by subjecting isobutylene, tertiary butanol, isobutyraldehyde or methacrolein to a gas phase reaction with a gas containing molecular oxygen in the presence of an oxidation catalyst is supplied to a quench tower A through a line 1, A part of the condensed condensate was circulated through the line 4 through the heat exchanger E to make countercurrent contact. A methacrylic acid aqueous solution containing methacrolein containing condensed methacrylic acid, water, etc. is sent to the heat exchanger F via the line 2 and is precipitated in the methacrylic acid deposited by being cooled to the gas temperature of the methacrolein absorption tower B at the top of the tower. The high boiling point substance is removed in the solid matter separator D and is supplied to the methacrolein recovery column C through the line 5.
On the other hand, the non-condensable gas containing most of the separated methacrolein is supplied from the top of the quenching tower A to the bottom of the methacrolein absorption tower B through the line 3 and obtained from the bottom of the methacrolein recovery tower C. A part of the methacrylic acid aqueous solution from which methacrolein has been removed is sent as a methacrolein absorbent through a line 12 to the top of the methacrolein absorption tower B for countercurrent contact. Methacrolein absorption tower B
The non-condensable gas from which methacrolein has been removed is discharged from the tower top line 7 of the above, and the methacrolein-containing methacrylic acid aqueous solution is supplied from the tower bottom of the methacrolein absorption tower B to the line 6
The methacrolein recovery tower C is merged with the methacrylic acid aqueous solution containing methacrolein from which the above-mentioned high-boiling substances have been removed and sent from the line 5 via a line 5, and is supplied to the middle stage of the methacrolein recovery tower C through a line 8 Methacrolein is recovered from the top of the tower C through line 9 or is directly circulated to the reactor as a raw material for methacrylic acid production.
The methacrolein-removed methacrylic acid aqueous solution obtained from the bottom of the methacrolein recovery tower C is partially passed through the line 12 as described above.
Then, the rest is sent to the next methacrylic acid refining step through the line 11.
以下、実施例により本発明を更に詳細に説明する。 Hereinafter, the present invention will be described in more detail with reference to Examples.
実施例１ 第１図のフローに従い、第３級ブタノールを原料とし
て、水蒸気、酸素、窒素と気相接触酸化反応を行い、得
られた組成がメタクロレイン0.72モル％、スチーム17.7
2モル％、窒素、酸素等の非凝縮性ガス78.72モル％、メ
タクリル酸1.92モル％の260℃反応生成ガスを、135Nm3/
Hの割合で急冷塔に供給した。Example 1 According to the flow of FIG. 1, a tertiary-butanol as a raw material was subjected to vapor-phase catalytic oxidation reaction with steam, oxygen and nitrogen, and the composition obtained was 0.72 mol% of methacrolein and 17.7 of steam.
2 mol%, nitrogen, non-condensable gases 78.72 mol% of oxygen or the like, the methacrylic acid 1.92 mol% of 260 ° C. the reaction product gas, 135 nm 3 /
The rate of H was supplied to the quench tower.
急冷塔において、熱交換器で20℃に制御されている予め
凝縮された凝縮液の一部と向流接触した前記反応生成ガ
スは、該塔頂よりメタクリル酸0.05モル％を含むメタク
ロレイン1.01モル％、スチーム1.25モル％の非凝縮性ガ
スを124Nm3/Hの割合でメタクロレイン吸収塔へ供給し
た。一方、凝縮したメタクロレイン0.32wt％を含むメタ
クリル酸25.66wt％、水64.57wt％、高沸点物質等9.51wt
％の組成を有するメタクリル酸水溶液は、34.29kg/Hの
割合で５℃で操作される熱交換器を介し、充填式フィル
ターを用いた固形物分離器において、析出したメタクリ
ル酸水溶液中の高沸点物質等を−５℃で濾別した後、メ
タクロレイン吸収塔缶出液と合流して次のメタクロレイ
ン回収塔に送った。この時充填式フィルターで除去され
た固形物は32g/Hであった。In the quench tower, the reaction product gas countercurrently contacted with a part of the condensed liquid that was previously condensed at 20 ° C. in the heat exchanger was 1.01 mol of methacrolein containing 0.05 mol% of methacrylic acid from the top of the tower. %, Steam 1.25 mol% non-condensable gas was supplied to the methacrolein absorber at a rate of 124 Nm 3 / H. On the other hand, 25.66 wt% of methacrylic acid containing 0.32 wt% of condensed methacrolein, 64.57 wt% of water, 9.51 wt% of high boiling substances, etc.
% Methacrylic acid aqueous solution has a high boiling point in the precipitated methacrylic acid aqueous solution in a solids separator using a packed filter through a heat exchanger operated at 5 ° C. at a rate of 34.29 kg / H. After the substances and the like were separated by filtration at -5 ° C, they were combined with the bottom liquid of the methacrolein absorption tower and sent to the next methacrolein recovery tower. At this time, the solid matter removed by the filling filter was 32 g / H.
10℃で操作されるメタクロレイン吸収塔において、供給
した非凝縮性ガスは、メタクロレイン回収塔でメタクロ
レインの除去されたメタクリル酸水溶液の一部と向流接
触せしめ、メタクロレインが吸収され、吸収塔塔頂より
メタクロレインの除去された10℃の非凝縮性ガスとして
放出され、吸収塔塔底部よりは、メタクロレイン1.66wt
％を含むメタクリル酸24.12wt％、水65.90wt％、その他
8.34wt％のメタクリル酸水溶液178.3kg/Hを缶出し、前
述の急冷塔缶出液と合流して212.6kg/Hをメタクロレイ
ン回収塔中段に供給した。In the methacrolein absorption tower operated at 10 ° C, the supplied non-condensable gas is brought into countercurrent contact with part of the methacrylic acid aqueous solution from which methacrolein has been removed in the methacrolein recovery tower to absorb and absorb methacrolein. The methacrolein was removed from the top of the tower as non-condensable gas at 10 ° C, and methacrolein 1.66wt from the bottom of the absorption tower.
% Methacrylic acid containing 24.12 wt%, water 65.90 wt%, other
178.3 kg / H of 8.34 wt% methacrylic acid aqueous solution was discharged from the can, and combined with the above-mentioned liquid discharged from the quenching tower, 212.6 kg / H was supplied to the middle stage of the methacrolein recovery tower.
メタクロレイン回収塔において塔底温度88℃、圧力500m
mHgで蒸留して回収塔塔頂よりメタクロレインを回収し
た。該塔底よりは、メタクロレインを含まないメタクリ
ル酸24.88wt％、水66.68wt％、その他8.44wt％のメタク
リル酸水溶液を得た。そのうち168.09kg/Hをメタクロレ
インの吸収剤としてメタクロレイン吸収塔に循環し、残
り40.12kg/Hは、次工程のメタクリル酸精製工程へ送っ
た。In the methacrolein recovery tower, the bottom temperature is 88 ℃ and the pressure is 500m.
Distilled at mHg, methacrolein was recovered from the top of the recovery tower. From the bottom of the column, a methacrylic acid aqueous solution containing methacrolein-free 24.88 wt% methacrylic acid, 66.68 wt% water, and 8.44 wt% was obtained. Of this, 168.09 kg / H was circulated to the methacrolein absorption tower as a methacrolein absorbent, and the remaining 40.12 kg / H was sent to the methacrylic acid refining step, which is the next step.
この様にして90日間連続運転したが、各塔および全ライ
ン共に圧力の変化は見られず安定に運転が可能なことを
認めた。また、塔を解体し充填物および内壁への固形物
の付着を調べたが、殆ど付着は見られず、更に連続運転
が可能であることを認めた。Although continuous operation was performed for 90 days in this way, no change in pressure was observed in each column and all lines, and it was confirmed that stable operation was possible. Further, the tower was disassembled and the adhesion of the solid matter to the packing and the inner wall was examined, but almost no adhesion was observed, and it was confirmed that continuous operation was possible.
比較例１ 急冷塔塔底より缶出したメタクリル酸水溶液の冷却およ
び固形物分離を行わない以外は実施例１と同様に運転し
たところ、５日目位からメタクロレイン吸収塔の圧力に
変動が生じ始め、10日目でフラッディングしたため運転
を中止し、塔を解体点検したところ充填物にかなりの固
形物が付着しており塔内が閉塞気味であった。Comparative Example 1 The same operation as in Example 1 was carried out except that the methacrylic acid aqueous solution discharged from the bottom of the quenching tower was not cooled and the solids were not separated, and the pressure of the methacrolein absorption tower fluctuated from the 5th day. At the beginning, the operation was stopped due to flooding on the 10th day, and when the tower was dismantled and inspected, a considerable amount of solid matter adhered to the packing and the inside of the tower was slightly blocked.
実施例２ 熱交換器および固形物分離器の設置場所を急冷塔缶出ラ
インから、メタクロレイン回収塔缶出ラインに変更した
以外は、実施例１と同様に運転したところ、充填式フィ
ルターには30g/Hの固形物が得られ、90日間連続運転に
おいても、各塔および全ライン共に圧力の変化は見られ
ず安定に運転を行うことができた。また、塔を解体し充
填物および内壁への固形物の付着を調べたが、殆ど付着
は見られず、更に連続運転が可能であることを認めた。Example 2 The operation was performed in the same manner as in Example 1 except that the heat exchanger and the solids separator were installed at different locations from the quench tower bottom line to the methacrolein recovery tower bottom line. A solid content of 30 g / H was obtained, and even in continuous operation for 90 days, no change in pressure was observed in each column and all lines, and stable operation was possible. Further, the tower was disassembled and the adhesion of the solid matter to the packing and the inner wall was examined, but almost no adhesion was observed, and it was confirmed that continuous operation was possible.
本発明により極めて効率良くメタクロレインの回収がで
き、長期の運転を可能にしたプロセスを提供することが
でき産業上利用価値が高い。INDUSTRIAL APPLICABILITY According to the present invention, methacrolein can be recovered extremely efficiently, and a process that enables long-term operation can be provided, which has high industrial utility value.
第１図は、本発明の一実施例によるフロー図である。 Ａ……急冷塔、Ｂ……メタクロレイン吸収塔、 Ｃ……メタクロレイン回収塔、 Ｄ固形物分離器、E.F.G……熱交換器、 １〜12……ライン FIG. 1 is a flow chart according to an embodiment of the present invention. A ... Quenching tower, B ... Methacrolein absorption tower, C ... Methacrolein recovery tower, D solids separator, E.F.G ... Heat exchanger, 1-12 ... Line
───────────────────────────────────────────────────── フロントページの続き (72)発明者 瀬川 博三 新潟県北蒲原郡中条町協和町２―１ (72)発明者 與口 勝治 大阪府高石市加茂４―７―411 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirozo Segawa 2-1 Kyowa-cho, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture (72) Inventor Katsuji Yoguchi 4-7-411 Kamo, Takaishi-shi, Osaka
Claims (1)
チルアルデヒドまたはメタクロレインを酸化触媒の存在
下に分子状酸素を含有するガスと気相反応させて得られ
る反応生成ガスからメタクロレインを回収する方法にお
いて、該反応生成ガスを予め凝縮させた凝縮液の一部と
10〜75℃の温度で向流接触せしめる急冷塔に供給して該
反応生成ガス中のメタクリル酸と水とを凝縮分離し、一
方、大部分のメタクロレインを含む非凝縮性ガスを５〜
30℃で操作されるメタクロレイン吸収塔塔底部に供給
し、吸収塔塔頂部よりメタクリル酸水溶液を供給してメ
タクロレインを吸収分離し、メタクロレイン以外の非凝
縮性ガスを吸収塔塔頂より放出し、吸収塔塔底より缶出
するメタクロレインを含むメタクリル酸水溶液を、急冷
塔より缶出した凝縮液の一部をメタクロレイン吸収塔の
塔頂ガス温度よりも低い温度まで冷却して生成する固形
物を固形物分離器で除去した急冷塔凝縮液と別々にまた
は合流して、塔底温度が100℃以下で操作されるメタク
ロレイン回収塔中段に供給し、回収塔塔頂よりメタクロ
レインを分離回収し、回収塔塔底よりメタクロレインの
分離されたメタクリル酸水溶液の一部をメタクロレイン
の吸収剤としてメタクロレイン吸収塔塔頂部へ循環する
ことを特徴とするメタクロレインの吸収方法。1. A method for recovering methacrolein from a reaction product gas obtained by subjecting isobutylene, tertiary butanol, isobutyraldehyde or methacrolein to a gas phase reaction with a gas containing molecular oxygen in the presence of an oxidation catalyst. , A part of a condensate obtained by previously condensing the reaction product gas
The reaction product gas is supplied to a quenching tower which is brought into countercurrent contact at a temperature of 10 to 75 ° C. to condense and separate methacrylic acid and water in the reaction product gas, while the non-condensable gas containing most of methacrolein is
It is supplied to the bottom of the methacrolein absorption tower operated at 30 ° C, the aqueous solution of methacrylic acid is supplied from the top of the absorption tower to absorb and separate methacrolein, and non-condensable gases other than methacrolein are released from the top of the absorption tower. Then, a methacrylic acid aqueous solution containing methacrolein discharged from the bottom of the absorption tower is produced by cooling a part of the condensate discharged from the quenching tower to a temperature lower than the top gas temperature of the methacrolein absorption tower. Separate or combine the solids with the quenching tower condensate removed by the solids separator, and supply to the middle stage of the methacrolein recovery tower operated at a tower bottom temperature of 100 ° C or less, and collect methacrolein from the top of the recovery tower. Separated and recovered, a part of the aqueous solution of methacrylic acid from which methacrolein has been separated from the bottom of the recovery tower is circulated to the top of the methacrolein absorption tower as an absorbent of methacrolein. Absorption method of Lorraine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6721088A JPH0764776B2 (en) | 1988-03-23 | 1988-03-23 | How to absorb methacrolein |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6721088A JPH0764776B2 (en) | 1988-03-23 | 1988-03-23 | How to absorb methacrolein |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01242547A JPH01242547A (en) | 1989-09-27 |
| JPH0764776B2 true JPH0764776B2 (en) | 1995-07-12 |
Family
ID=13338320
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6721088A Expired - Lifetime JPH0764776B2 (en) | 1988-03-23 | 1988-03-23 | How to absorb methacrolein |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0764776B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4225321A1 (en) * | 1992-07-31 | 1994-02-03 | Basf Ag | Process for the separation of methacrolein from a gaseous mixture |
| MY120051A (en) * | 1997-07-30 | 2005-08-30 | Mitsubishi Rayon Co | Process for purification of (meth)acrylic acid |
| EP2085376B1 (en) | 2008-01-30 | 2012-09-05 | Evonik Röhm GmbH | Process for preparation of high purity methacrylic acid |
| JP5407486B2 (en) * | 2008-03-31 | 2014-02-05 | 三菱化学株式会社 | Method for producing (meth) acrylic acid and / or (meth) acrolein |
| WO2013163806A1 (en) | 2012-05-03 | 2013-11-07 | Evonik Industries Ag | Process for preparation of highly pure, non-yellowing methacrylic acid |
| EP2976320B1 (en) | 2013-03-18 | 2020-02-12 | Röhm GmbH | Process for preparation of methacrylic acid and methacrylic acid esters |
-
1988
- 1988-03-23 JP JP6721088A patent/JPH0764776B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01242547A (en) | 1989-09-27 |
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