JPH0222061B2 - - Google Patents
Info
- Publication number
- JPH0222061B2 JPH0222061B2 JP55184499A JP18449980A JPH0222061B2 JP H0222061 B2 JPH0222061 B2 JP H0222061B2 JP 55184499 A JP55184499 A JP 55184499A JP 18449980 A JP18449980 A JP 18449980A JP H0222061 B2 JPH0222061 B2 JP H0222061B2
- Authority
- JP
- Japan
- Prior art keywords
- column
- trimethylamine
- separation
- dimethylamine
- ammonia
- 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.)
- Expired - Lifetime
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Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
本発明はメチルアミン類の蒸留分離方法に関す
る。
メチルアミン類はアンモニアとメタノールを脱
水触媒存在下気相接触させて製造することが出来
るが、このようにして得られた反応生成物はアン
モニア、モノメチルアミン、ジメチルアミン、ト
リメチルアミン、メタノール及び水の混合物であ
り、これらを蒸留塔を用い分離する必要がある。
通常これらの成分を分離精製するには４〜５基の
蒸留塔が必要であるが、メチルアミン類各異性体
は互いに沸点が接近し、これらを蒸留により分離
精製するには塔頂留出蒸気の凝縮、塔底液の加熱
等に多くのエネルギーを必要とする。本発明はこ
れらエネルギー消費の少ないメチルアミン類の蒸
留分離方法を提供するもので、メタノールとアン
モニアを反応させて得た反応生成液をアンモニア
分離塔に導き反応生成液からアンモニアの全量と
トリメチルアミンの一部を共沸混合物として塔頂
から留去し、塔底抜出液をトリメチルアミン分離
塔に導き塔頂付近より水を加え、水抽出蒸留によ
りトリメチルアミンを塔頂より留出させ、塔底液
を脱水塔に導き塔頂よりモノメチルアミン及びジ
メチルアミンを留出させることにより水及びメタ
ノールを塔底缶出液として分離し、次いで塔頂留
出物をモノ・ジメチルアミン分離塔に導き塔頂よ
りモノメチルアミン、塔底よりジメチルアミン
を、それぞれ留出物及び缶出液として分離するメ
チルアミン類の蒸留分離方法において、
ａ アンモニア分離塔の塔頂留出蒸気を凝縮させ
て得られる凝縮液の一部を脱水塔の留出蒸気を
凝縮させる冷却媒体として使用すること及び／
又は
ｂ トリメチルアミン分離塔の塔頂留出蒸気を、
モノ・ジメチルアミン分離塔の塔底液の加熱媒
体として使用する
メチルアミン類の蒸留分離方法である。
本発明を図面に基づいて説明すると、メタノー
ルとアンモニアを反応させて得た反応生成液１は
先ず段数20段以上、15〜20Kg／cm2の圧力下で操作
されるアンモニア分離塔２で未反応アンモニアを
分離するが、この際トリメチルアミン及び少量の
モノメチルアミンが共沸混合物を形成して同時に
留出する。これは水冷却により凝縮させ、一部は
アンモニア分離塔に１以上の還流比で還流し残り
は反応系に戻すのが通常であるが、本発明におい
ては還流以外の凝縮液を脱水塔５の留出蒸気を凝
縮させる冷却媒体として使用したのち反応系へ循
環する。一方アンモニア分離塔の塔底から抜き出
される缶出液は段数30段以上、還流比１以上、圧
力７〜20Kg／cm2の条件下操作されるトリメチルア
ミン分離塔３に導き、塔頂より水４を加え抽出蒸
留を行なう。添加する水の量は液組成、温度等に
よつても異なるが、大体導入液中のアルカリ分の
５〜20倍モル程度が適当である。かくて塔頂から
はトリメチルアミンが単離され、塔底缶出液は脱
水塔５に導かれる。脱水塔は段数20段以上、還流
比５以上、圧力５〜15Kg／cm2の条件下で操作さ
れ、塔頂からモノメチルアミン及びジメチルアミ
ンが留出される。缶出液は水及び少量のメタノー
ルでありそのまゝ廃出される。脱水塔塔頂留出物
は段数40段以上、還流比１以上、圧力５〜10Kg／
cm2の条件下で操作されるモノ−ジメチルアミン分
離塔６に導き塔頂よりモノメチルアミン、塔底よ
りモノメチルアミンが分離される。本発明におい
ては以上の工程においてトリメチルアミン分離塔
の操作圧をモノ―ジメチルアミンの操作圧よりも
２Kg／cm2以上、好ましくは３Kg／cm2以上高くする
ことによりモノ―ジメチルアミン分離塔の塔底再
沸器７の熱源としてトリメチルアミン分離塔の塔
頂留出物を使用するもので、これによりモノ―ジ
メチルアミン分離塔が必要とする熱量を大いに節
減する事が出来る。
実施例
18Kg／cm2Ｇにて操作されるアンモニア分離塔
に、アンモニア、2000Kg／Ｈ、モノメチルアミン
900Kg／Ｈ、ジメチルアミン650Kg／Ｈ、トリメチ
ルアミン1500Kg／Ｈ、反応水1500Kg／Ｈ及び未反
応メタノール20Kg／Ｈを含む反応生成液が仕込ま
れる。アンモニア分離塔の塔頂よりアンモニア
2000Kg／Ｈ、トリメチルアミン400Kg／Ｈ、モノ
メチルアミン30Kg／Ｈが留去される。これが約９
Kg／cm2Ｇの圧力にて操作される脱水塔の塔頂凝縮
器に入り約56℃で蒸発し、片や脱水塔の留出蒸気
は約62℃で凝縮する。他方アンモニア分離塔から
の缶出液は、10Kg／cm2Ｇの圧力にて操作されるト
リメチルアミン分離塔に入り、頂部より得られる
トリメチルアミンが蒸気として７Kg／cm2Ｇで操作
されるモノ―ジメチルアミン分離塔の再沸器に入
り、全量約84℃にて凝縮され、一方再沸器内部の
液は約70℃で沸騰させられる。
各蒸留塔留出液の各成分の液量および温度は次
の通りである。
The present invention relates to a method for separating methylamines by distillation. Methylamines can be produced by bringing ammonia and methanol into gas phase contact in the presence of a dehydration catalyst, but the reaction product thus obtained is a mixture of ammonia, monomethylamine, dimethylamine, trimethylamine, methanol, and water. Therefore, it is necessary to separate these using a distillation column.
Normally, 4 to 5 distillation columns are required to separate and purify these components, but the boiling points of each isomer of methylamines are close to each other, and to separate and purify them by distillation, it is necessary to use the distilled vapor distilled from the top of the column. A lot of energy is required for condensing the liquid and heating the bottom liquid. The present invention provides a method for distilling and separating methylamines with low energy consumption, by introducing the reaction product liquid obtained by reacting methanol and ammonia into an ammonia separation column, and extracting the total amount of ammonia and trimethylamine from the reaction product liquid. The liquid extracted from the bottom of the tower is led to a trimethylamine separation column, water is added from near the top of the column, trimethylamine is distilled out from the top of the column by water extractive distillation, and the bottom liquid is dehydrated. The monomethylamine and dimethylamine are distilled out from the top of the column to separate water and methanol as a bottom bottom liquid.Then, the top distillate is led to a mono-dimethylamine separation column and monomethylamine is distilled out from the top of the column. , in a distillation separation method for methylamines in which dimethylamine is separated from the bottom of the column as a distillate and bottoms, respectively, a part of the condensate obtained by condensing the vapor distilled from the top of the ammonia separation column is Use as a cooling medium to condense the distillate vapor of the dehydration tower; and/or
or b. The vapor distilled from the top of the trimethylamine separation column,
This is a method for distilling and separating methylamines, which is used as a heating medium for the bottom liquid of a mono-dimethylamine separation column. To explain the present invention based on the drawings, a reaction product liquid 1 obtained by reacting methanol and ammonia is first passed through an ammonia separation column 2 which has 20 or more plates and is operated under a pressure of 15 to 20 kg/cm 2 to unreact. The ammonia is separated off, with trimethylamine and a small amount of monomethylamine forming an azeotrope and distilling off at the same time. Normally, this is condensed by water cooling, a part of which is refluxed to an ammonia separation tower at a reflux ratio of 1 or more, and the rest is returned to the reaction system. The distillate vapor is used as a cooling medium to condense and then circulated to the reaction system. On the other hand, the bottoms extracted from the bottom of the ammonia separation column are led to the trimethylamine separation column 3, which is operated under the conditions of 30 or more plates, a reflux ratio of 1 or more, and a pressure of 7 to 20 kg/cm 2 . Add and perform extractive distillation. The amount of water to be added varies depending on the liquid composition, temperature, etc., but is approximately 5 to 20 times the molar amount of the alkaline content in the introduced liquid. Trimethylamine is thus isolated from the top of the column, and the bottom liquid is led to the dehydration column 5. The dehydration tower is operated under conditions of 20 or more plates, a reflux ratio of 5 or more, and a pressure of 5 to 15 kg/cm 2 , and monomethylamine and dimethylamine are distilled from the top of the tower. The bottom liquor is water and a small amount of methanol and is directly disposed of. The top distillate of the dehydration tower has a number of plates of 40 or more, a reflux ratio of 1 or more, and a pressure of 5 to 10 kg/
The mixture is introduced into a mono-dimethylamine separation column 6 which is operated under conditions of 2 cm2, and monomethylamine is separated from the top of the column, and monomethylamine is separated from the bottom of the column. In the present invention, in the above steps, the operating pressure of the trimethylamine separation column is made higher than the operating pressure of mono-dimethylamine by 2 Kg/cm 2 or more, preferably 3 Kg/cm 2 or more, so that the bottom of the mono-dimethylamine separation column is The overhead distillate of the trimethylamine separation column is used as a heat source for the reboiler 7, which can greatly reduce the amount of heat required by the mono-dimethylamine separation column. Example Ammonia, 2000Kg/H, and monomethylamine were added to an ammonia separation column operated at 18Kg/cm 2 G.
A reaction product liquid containing 900 Kg/H, dimethylamine 650 Kg/H, trimethylamine 1500 Kg/H, reaction water 1500 Kg/H and unreacted methanol 20 Kg/H is charged. Ammonia from the top of the ammonia separation tower
2000 Kg/H, trimethylamine 400 Kg/H, and monomethylamine 30 Kg/H are distilled off. This is about 9
The vapor enters the top condenser of the dehydration tower operated at a pressure of Kg/cm 2 G and evaporates at about 56°C, and the distillate vapor from the dehydration tower is condensed at about 62°C. On the other hand, the bottoms from the ammonia separation tower enters a trimethylamine separation tower operated at a pressure of 10 Kg/cm 2 G, and the trimethylamine obtained from the top is converted into vapor into mono-dimethylamine operated at a pressure of 7 Kg/cm 2 G. The liquid enters the reboiler of the separation column and is condensed at about 84°C, while the liquid inside the reboiler is boiled at about 70°C. The liquid amount and temperature of each component of each distillation column distillate are as follows.
【表】
モノ・ジメチルアミン分離塔のスチーム使用量
は、本発明の如き熱交換を行わない場合には
2.2T／Ｈ必要であつたが、トリメチルアミン分
離塔よりの蒸気をモノ・ジメチルアミン分離塔の
再沸器の熱源として用いることにより0.7T／Ｈ
となり、1.5T／Ｈのスチームが節減された。
冷却水使用量は、本発明の如き熱交換を行わな
い場合にはトリメチルアミン分離塔で71T／Ｈ、
脱水塔で54T／Ｈ必要であつたが、トリメチルア
ミン分離塔よりの蒸気をモノ・ジメチルアミン分
離塔の再沸器の熱源として用いることによりトリ
メチルアミン分離塔の冷却水が不要となつた。ま
た脱水塔の冷却水使用量は54T／Ｈ必要であつた
ものが、アンモニア分離塔の留出液と脱水塔の供
給液を熱交換させることにより35T／Ｈとなつ
た。従つて冷却水は71＋（54−35）＝90T／Ｈ節減
された。[Table] The amount of steam used in the mono/dimethylamine separation tower is
2.2T/H was required, but by using the steam from the trimethylamine separation tower as a heat source for the reboiler of the mono/dimethylamine separation tower, the reduction was reduced to 0.7T/H.
As a result, 1.5T/H of steam was saved. The amount of cooling water used is 71T/H in the trimethylamine separation tower when heat exchange is not performed as in the present invention.
The dehydration tower required 54 T/H, but by using the steam from the trimethylamine separation tower as a heat source for the reboiler of the mono/dimethylamine separation tower, cooling water for the trimethylamine separation tower was no longer necessary. The amount of cooling water used in the dehydration tower was 54 T/H, but was reduced to 35 T/H by heat exchange between the distillate of the ammonia separation tower and the feed liquid of the dehydration tower. Therefore, cooling water was saved by 71+(54-35)=90T/H.
第１図は本発明方法を実施するための工程図で
ある。
FIG. 1 is a process diagram for implementing the method of the present invention.
Claims (1)
応生成液をアンモニア分離塔に導き該反応生成液
からアンモニアの全量とトリメチルアミンの一部
を共沸混合物として塔頂から留去し、塔底抜出液
をトリメチルアミン分離塔に導き塔頂付近より水
を加え、水抽出蒸留によりトリメチルアミンを塔
頂より留出させ、塔底液を脱水塔に導き塔頂より
モノメチルアミン及びジメチルアミンを留出させ
ることにより水及びメタノールを塔底缶出液とし
て分離し、次いで塔頂留出物をモノ・ジメチルア
ミン分離塔に導き塔頂よりモノメチルアミン、塔
底よりジメチルアミンを、それぞれ留出物及び缶
出液として分離するメチルアミン類の蒸留方法に
おいて、アンモニア分離塔の圧力を15〜20Kg／
cm2、トリメチルアミン分離塔の圧力を７〜20Kg／
cm2、脱水塔の圧力を５〜15Kg／cm2、モノ・ジメチ
ルアミン分離塔の圧力を５〜15Kg／cm2とし、且つ
トリメチルアミン分離塔の操作圧をモノ・ジメチ
ルアミン分離塔の操作圧よりも２Kg／cm2以上高く
すると共に、アンモニア分離塔の塔頂留出蒸気を
凝縮させて得られる凝縮液の一部を脱水塔の留出
蒸気を凝縮させる冷却媒体として使用すること及
び／又はトリメチルアミン分離塔の塔頂留出蒸気
を、モノ・ジメチルアミン分離塔の塔底液の加熱
媒体として使用することを特徴とするメチルアミ
ン類の蒸留方法。1. The reaction product liquid obtained by reacting methanol and ammonia is introduced into an ammonia separation column, and from the reaction product liquid, the entire amount of ammonia and a part of trimethylamine are distilled off from the top of the column as an azeotrope, and the liquid extracted from the bottom of the column is collected. Water is added to the trimethylamine separation column near the top of the column, trimethylamine is distilled out from the top of the column by water extractive distillation, and monomethylamine and dimethylamine are distilled out from the top of the column by introducing the bottom liquid to a dehydration column. Methanol is separated as a bottom distillate, and then the top distillate is led to a mono/dimethylamine separation column, where monomethylamine is separated from the top of the column and dimethylamine is separated from the bottom as a distillate and a bottom solution, respectively. In the distillation method of methylamines, the pressure of the ammonia separation column is set to 15 to 20 kg/
cm 2 , the pressure of the trimethylamine separation tower is 7 to 20 kg/
cm 2 , the pressure of the dehydration tower is 5 to 15 Kg/cm 2 , the pressure of the mono/dimethylamine separation tower is 5 to 15 Kg/cm 2 , and the operating pressure of the trimethylamine separation tower is lower than the operating pressure of the mono/dimethylamine separation tower. In addition , a portion of the condensate obtained by condensing the top distillate vapor of the ammonia separation column is used as a cooling medium to condense the distillate vapor of the dehydration column, and/or trimethylamine A method for distilling methylamines, characterized in that the vapor distilled from the top of a separation column is used as a heating medium for the bottom liquid of a mono/dimethylamine separation column.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18449980A JPS57108041A (en) | 1980-12-25 | 1980-12-25 | Distilling and separating method of methylamine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18449980A JPS57108041A (en) | 1980-12-25 | 1980-12-25 | Distilling and separating method of methylamine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57108041A JPS57108041A (en) | 1982-07-05 |
| JPH0222061B2 true JPH0222061B2 (en) | 1990-05-17 |
Family
ID=16154250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18449980A Granted JPS57108041A (en) | 1980-12-25 | 1980-12-25 | Distilling and separating method of methylamine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57108041A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6045550A (en) * | 1983-08-22 | 1985-03-12 | Nitto Chem Ind Co Ltd | Production of methylamine compound |
| DE10344282A1 (en) * | 2003-09-24 | 2005-04-21 | Basf Ag | Method for preventing corrosion |
| KR101200218B1 (en) * | 2004-06-01 | 2012-11-09 | 바이엘 머티리얼사이언스 아게 | Process for the Distillative Separation of Aqueous Amine Solutions |
| DE102004026626A1 (en) * | 2004-06-01 | 2005-12-29 | Bayer Materialscience Ag | Process for the distillative separation of aqueous amine solutions |
| CN102976950A (en) * | 2012-12-18 | 2013-03-20 | 天津天智精细化工有限公司 | Improved process for preparing tertiary amine |
| CN107245036A (en) * | 2017-06-21 | 2017-10-13 | 浙江普洛康裕制药有限公司 | The method and apparatus of methylamine and the application in ephedrine and process of producing Pseudoephedrine are separated from the reaction waste containing methylamine |
| CN112745228A (en) * | 2020-12-30 | 2021-05-04 | 天津天南同创科技发展有限公司 | Energy-saving separation process device and method for high-purity monomethylamine and dimethylamine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5168506A (en) * | 1974-12-11 | 1976-06-14 | Nitto Chemical Industry Co Ltd | Mechiruaminno seiseiho |
-
1980
- 1980-12-25 JP JP18449980A patent/JPS57108041A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57108041A (en) | 1982-07-05 |
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