JPH07233125A - Production of methylamine - Google Patents

Production of methylamine

Info

Publication number
JPH07233125A
JPH07233125A JP6305898A JP30589894A JPH07233125A JP H07233125 A JPH07233125 A JP H07233125A JP 6305898 A JP6305898 A JP 6305898A JP 30589894 A JP30589894 A JP 30589894A JP H07233125 A JPH07233125 A JP H07233125A
Authority
JP
Japan
Prior art keywords
methylamine
ammonia
tma
mixture
reaction
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
Application number
JP6305898A
Other languages
Japanese (ja)
Other versions
JP3213497B2 (en
Inventor
Takeshi Yasutake
剛 安武
Atsuhiko Hiai
淳彦 日合
Yukihiro Yoda
幸廣 與田
Tokuyuki Iwanaga
徳幸 岩永
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Toatsu Chemicals Inc
Original Assignee
Mitsui Toatsu Chemicals Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsui Toatsu Chemicals Inc filed Critical Mitsui Toatsu Chemicals Inc
Priority to JP30589894A priority Critical patent/JP3213497B2/en
Publication of JPH07233125A publication Critical patent/JPH07233125A/en
Application granted granted Critical
Publication of JP3213497B2 publication Critical patent/JP3213497B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/50Improvements relating to the production of bulk chemicals
    • Y02P20/52Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Landscapes

  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

PURPOSE:To obtain methylamine through simplified processes without the need for TMA separation. CONSTITUTION:In a method for producing methylamine by subjecting methanol, ammonia and a methylamine mixture to vapor phase catalytic reaction, the following processes are made consecutively: disproportionation process: the ammonia and methylamine are subjected to catalytic reaction in the presence of a solid acid catalyst <=15Angstrom in average fine pore diameter to decrease the amount of trimethylamine; the chief reaction process: part or the whole of the resultant methylamine-contg. mixture, the methanol and ammonia are subjected to catalytic reaction in the presence of a silylated solid acid catalyst; and the 1st distillation process: the resultant methylamine-contg. mixture, or its mixture with part of the methylamine-contg. mixture obtained from the disproportionation process is distilled under a pressure of 10-25kg/cm<2>.G to distill off virtually the whole amount of the trimethylamine in said mixture via the top of the distillation column in the form of an azeotropic mixture with the ammonia and this trimethylamin is then fed to the disproportionation process.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、メタノールとアンモニ
アの反応によりメチルアミンを製造する方法に関する。
より詳しくは、需要の低いトリメチルアミンを製造しな
いメチルアミンの製造方法に関する。
FIELD OF THE INVENTION The present invention relates to a method for producing methylamine by reacting methanol with ammonia.
More specifically, it relates to a method for producing methylamine that does not produce trimethylamine, which is in low demand.

【0002】[0002]

【従来の技術及び発明が解決しようとする課題】メチル
アミンは一般的には、固体酸触媒の存在下、メタノール
とアンモニアを気相中300℃〜400℃で反応させる
ことにより下記の(1)〜(3)の反応式に従って製造
され、メチル基の置換数の相違によりモノ、ジ、トリの
3種類が混合して生成する。
BACKGROUND OF THE INVENTION Methylamine is generally prepared by reacting methanol and ammonia in the gas phase at 300 ° C. to 400 ° C. in the presence of a solid acid catalyst. To (3), the three types of mono, di, and tri are mixed and produced depending on the difference in the number of substitutions of the methyl group.

【0003】 NH+CHOH → CHNH+HO (1) CHNH+CHOH → (CHNH+HO (2) (CHNH+CHOH → (CHN+HO (3) CHNH:モノメチルアミン(以下、MMAと略
記) (CHNH:ジメチルアミン (以下、DMAと
略記) (CHN :トリメチルアミン(以下、TMAと
略記)
NH 3 + CH 3 OH → CH 3 NH 2 + H 2 O (1) CH 3 NH 2 + CH 3 OH → (CH 3 ) 2 NH + H 2 O (2) (CH 3 ) 2 NH + CH 3 OH → (CH 3 ) 3 N + H 2 O (3) CH 3 NH 2 : monomethylamine (hereinafter abbreviated as MMA) (CH 3 ) 2 NH: dimethylamine (hereinafter abbreviated as DMA) (CH 3 ) 3 N: trimethylamine (hereinafter TMA) Abbreviated)

【0004】反応で得られた含メチルアミン混合物は、
その後の精製工程で分離精製され、それぞれ、化学薬品
や農薬、医薬、飼料等の原料として広く利用されてい
る。しかしながら、これらメチルアミン類の需要は一様
ではなく、その市場の95%以上をMMAとDMAが占
め、TMAは5%程度に過ぎない。また、メチルアミン
混合物の分離精製は一般に蒸留により行われるが、MM
A及びDMAとTMAとの沸点差が小さい、及びTMA
がMMA、DMAと共沸するという理由から3種類のメ
チルアミンを効率的に分離することは容易ではないた
め、合理的なメチルアミンの製造プロセスを確立するた
めにはこれらの点を考慮する必要がある。
The methylamine-containing mixture obtained by the reaction is
It is separated and refined in the subsequent refining process, and is widely used as a raw material for chemicals, agricultural chemicals, medicines, feeds, and the like. However, the demand for these methylamines is not uniform, and MMA and DMA occupy 95% or more of the market, and TMA accounts for only about 5%. The separation and purification of the methylamine mixture is generally carried out by distillation.
Small difference in boiling point between A and DMA and TMA, and TMA
It is not easy to efficiently separate three kinds of methylamines because they azeotrope with MMA and DMA, so it is necessary to consider these points in order to establish a rational methylamine production process. There is.

【0005】従来の一般的なメチルアミンの製造方法に
よれば、主反応工程に於いて固体酸触媒の存在下に生成
したメチルアミンと過剰に供給したアンモニア、未反応
のメタノール、及び副生成物の水を含む混合物は、第一
蒸留操作に於いてアンモニアまたは、アンモニアとメチ
ルアミンの一部が留出し、その留出物は主反応工程、ま
たは不均化反応工程に循環される。第二蒸留塔では先に
述べたようにMMA、DMAとTMAとの沸点差が小さ
い、TMAがMMA、DMAと共沸するという理由から
水による抽出蒸留でTMAを留出させ、缶出液を第三蒸
留塔に供給しMMAとDMAの混合物を留出させ、この
留出物を第四蒸留塔に供給し、塔頂からMMAを塔底か
らDMAを分離するプロセスをたどる。
According to the conventional general method for producing methylamine, methylamine produced in the presence of a solid acid catalyst in the main reaction step, ammonia supplied in excess, unreacted methanol, and by-products. In the first distillation operation, the water-containing mixture distills off ammonia or a part of ammonia and methylamine, and the distillate is recycled to the main reaction step or the disproportionation reaction step. In the second distillation column, as described above, the boiling point difference between MMA, DMA and TMA is small, and because TMA is azeotroped with MMA and DMA, TMA is distilled by extractive distillation with water, and the bottom liquid is The process of feeding the mixture to the third distillation column to distill a mixture of MMA and DMA, feeding this distillate to the fourth distillation column, and separating MMA from the top of the column and DMA from the bottom of the column is followed.

【0006】従来の製造方法に於ける問題点は、主反応
工程で生成する各メチルアミンの生成比率は熱力学的に
決定されるものに近いものであり、反応条件によって自
由に制御ができるものではないという点、より具体的に
言えば、市場の需要量よりもTMAの生成比率が高くな
るため、過剰に生成するTMAは再度反応工程に循環す
る必要があるという点と、第二蒸留塔(第二蒸留塔以降
図面に記載なし)で行う抽出蒸留はMMAとDMAに対
して数倍量の抽出水を必要とするため排水量の増大を招
き、また第三蒸留塔に於いてその多量の抽出水を含む液
の蒸留を行うことから、莫大な回収エネルギーを必要と
するという点である。
The problem with the conventional production method is that the production ratio of each methylamine produced in the main reaction step is close to that determined thermodynamically, and can be freely controlled by the reaction conditions. However, more specifically, since the TMA production ratio is higher than the market demand, the excess TMA needs to be recycled to the reaction step, and the second distillation column Extractive distillation conducted in (not shown in the drawings after the second distillation column) requires several times the amount of extracted water with respect to MMA and DMA, which leads to an increase in the amount of waste water, and in the third distillation column, a large amount of the extracted water is required. Since the liquid containing the extracted water is distilled, a huge amount of recovery energy is required.

【0007】先にも述べたようにTMAは需要が低く、
これを分離するために抽出蒸留のようなエネルギー原単
位の悪い操作を施すことは、決して合理的な方法である
とはいえない。これらを考えると、合理的なメチルアミ
ン製造プロセスとは、TMAの生成量を抑制し、MMA
とDMAの生成比率を高めるプロセス、またその反応生
成物を効率的に精製分離することができるプロセスとい
うことができる。ここで効率的な精製分離とは、プロセ
スを簡略化し、エネルギー原単位を向上して安価に精製
を行うことを意味する。具体的には、TMAの分離操作
をなくし、エネルギー原単位の向上や排水量削減等を目
指す方法である。
As mentioned above, the demand for TMA is low,
It is not a rational method to carry out a bad operation of energy intensity such as extractive distillation to separate this. Considering these, the rational methylamine production process is to suppress the production amount of TMA,
It can be said that it is a process of increasing the production ratio of and DMA, and a process of efficiently purifying and separating the reaction product. Here, the efficient purification separation means that the process is simplified, the energy consumption rate is improved, and the purification is performed at low cost. Specifically, it is a method aimed at improving the energy intensity and reducing the amount of wastewater by eliminating the TMA separation operation.

【0008】しかしながら、TMAの生成量抑制に関し
ていえば、先にも述べたように各メチルアミンの生成比
率は熱力学的に決定されるものに近いものであり、例え
ばアンモニアとメタノールからメチルアミンの生成反応
を行った場合、TMAの生成比率は、反応温度や反応器
入口に於ける原料の窒素/炭素mol比(以下単にN/
C比と略記する)の条件によって異なるが、概ね40〜
60重量%の範囲となる。即ち、条件によって自由に制
御ができるものではない。
However, regarding the suppression of the amount of TMA produced, as described above, the production ratio of each methylamine is close to that which is determined thermodynamically, and for example, from ammonia and methanol to methylamine. When the production reaction is carried out, the production ratio of TMA depends on the reaction temperature and the nitrogen / carbon molar ratio of the raw material at the reactor inlet (hereinafter simply referred to as N /
It is approximately 40-
It is in the range of 60% by weight. That is, it cannot be freely controlled depending on the conditions.

【0009】これに対し、特公昭62−47172号公
報では、平均細孔径20Å以上の多孔質固体酸触媒の存
在下に於いてTMA量を減少させる第一工程と、有効細
孔径10Å以下の多孔質固体酸触媒の存在下でメチルア
ミンの生成反応を行う第二工程との結合により、メチル
アミンの製造を行う方法が開示されている。この方法に
よれば、第二工程に使用する触媒の立体的な障害によっ
て生成物中で最も分子径の大きいTMAの細孔内からの
離脱を妨げ、この結果TMA生成反応を抑制し、MMA
とDMAを高収率で得ることができる。従って、DMA
の精製工程のエネルギー原単位の向上、及び装置の小型
化が達成できる。また需要の少ないTMAは第一工程に
リサイクルし、ここでメチルアミン混合物及びアンモニ
アと反応して、その量を減少させ、再度原料として第二
工程に付与するという方法であり、需要に見合った比率
で各メチルアミンの製造をなす方法である。
On the other hand, in Japanese Patent Publication No. 62-47172, the first step of reducing the amount of TMA in the presence of a porous solid acid catalyst having an average pore diameter of 20 Å or more, and a pore having an effective pore diameter of 10 Å or less. Disclosed is a method for producing methylamine by combining with a second step of carrying out a reaction for producing methylamine in the presence of a solid acid catalyst. According to this method, the steric hindrance of the catalyst used in the second step prevents TMA, which has the largest molecular diameter in the product, from leaving the pores, and as a result, suppresses the TMA formation reaction,
And DMA can be obtained in high yield. Therefore, DMA
It is possible to improve the energy intensity of the refining process and reduce the size of the device. In addition, TMA, which is in low demand, is recycled to the first step, where it reacts with the methylamine mixture and ammonia to reduce the amount and re-apply it as a raw material to the second step. Is a method for producing each methylamine.

【0010】しかしながらこの方法に於いてもなお、主
反応工程に於けるTMAの生成比率は約20〜30重量
%程度に低減できるに過ぎず、理由の詳細は後述するが
同公報に記載の如く、TMAの分離のために水による抽
出蒸留を必要とするため、エネルギー原単位の悪化や排
水量増大といった課題を解決することはできない。ここ
で、主反応工程に於けるTMAの生成比率とは、主反応
工程に於いて反応により増加した全メチルアミン中のT
MAの重量比率と定義する。
However, even in this method, the production ratio of TMA in the main reaction step can only be reduced to about 20 to 30% by weight, and the details of the reason will be described later, but as described in the publication. , TMA requires extractive distillation with water to separate it, and therefore problems such as deterioration of energy intensity and increase of wastewater cannot be solved. Here, the production ratio of TMA in the main reaction step means T in total methylamine increased by the reaction in the main reaction step.
It is defined as the weight ratio of MA.

【0011】その後、メチルアミンの生成をなす触媒を
更に限定し、熱力学的に計算される平衡値よりもTMA
の生成量をはるかに低減し、MMAやDMAを高収率で
得る方法が種々開示されている。例えば、天然産のモル
デナイトを触媒として使用する方法(特公平2−273
35号公報)、ランタンイオンでイオン交換したモルデ
ナイトを触媒として使用する方法(特公平3−2237
8号公報)、アルカリ金属の含有量を特定の範囲に限定
したモルデナイトを触媒として使用する方法(特公平2
−16743号公報)、ゼオライト触媒をスティーム処
理して使用する方法(特公平2−2876号公報)、バ
インダーを実質的に含まないA型ゼオライトを触媒とし
て使用する方法(特公平3−8331号公報)等が挙げ
られる。
Thereafter, the catalyst for the formation of methylamine was further limited, and the TMA was higher than the equilibrium value calculated thermodynamically.
Various methods have been disclosed in which MMA and DMA are obtained in a high yield by significantly reducing the production amount of. For example, a method using natural mordenite as a catalyst (Japanese Patent Publication No. 2-273).
No. 35), a method of using mordenite ion-exchanged with lanthanum ions as a catalyst (Japanese Patent Publication No. 3237/1990).
No. 8), a method of using mordenite with the content of alkali metal limited to a specific range as a catalyst (Japanese Patent Publication No. 2).
No. 16743), a method of steam-treating a zeolite catalyst (JP-B-2-2876), and a method of using an A-type zeolite substantially containing no binder as a catalyst (JP-B-3-8331). ) And the like.

【0012】これらの触媒を用いれば、TMAの生成量
を低減することができる。しかしながらこれらの方法に
於いてもなお、主反応工程に於けるTMAの生成比率は
約10重量%程度までしか低減することはできない。ま
た、特開平3−262540号公報には、モルデナイト
を四塩化炭素の気相化学反応で修飾する方法が開示され
ている。この方法によれば、TMAの生成量を更に低減
することができるが、工業的に安価に触媒を調整するこ
とは困難であり、更に、これらいずれの方法においても
反応生成物から効率的にメチルアミンを精製する方法に
まで言及したものではなかった。
If these catalysts are used, the amount of TMA produced can be reduced. However, even in these methods, the production ratio of TMA in the main reaction step can only be reduced to about 10% by weight. Further, JP-A-3-262540 discloses a method of modifying mordenite by a gas phase chemical reaction of carbon tetrachloride. According to this method, it is possible to further reduce the amount of TMA produced, but it is difficult to adjust the catalyst industrially at low cost. Furthermore, in any of these methods, it is possible to efficiently generate methyl from the reaction product. It was not even mentioned how to purify the amine.

【0013】本発明の目的は、単に需要の高いMMAと
DMAを高収率で得ることにとどまらず、メチルアミン
を効率的に、かつ安価に製造する方法を提供することに
ある。更に具体的にいえば、エネルギー原単位の悪化や
排水量増大といった問題を招くTMAの分離操作を省略
し、工程を簡略化したメチルアミンの製造方法を提供す
ることにある。
An object of the present invention is not only to obtain MMA and DMA, which are in high demand, in high yield, but also to provide a method for producing methylamine efficiently and inexpensively. More specifically, it is an object of the present invention to provide a method for producing methylamine that simplifies the steps by omitting the TMA separation operation that causes problems such as deterioration in energy consumption rate and increase in wastewater amount.

【0014】[0014]

【課題を解決するための手段】本発明者らは、主反応工
程に於けるTMAの生成量を低減すること、TMAの分
離操作を省略しエネルギー原単位を向上すること等、合
理的なメチルアミン製造プロセスを確立するため鋭意検
討を進めてきた。この結果、不均化工程に特定の細孔径
の固体酸触媒を、主反応工程にシリル化処理した固体酸
触媒を用い、さらに特定の圧力で蒸留操作を行えば上記
目的を達成することを見出した。
[Means for Solving the Problems] The inventors of the present invention reasonably reduce the amount of TMA produced in the main reaction step, omit the TMA separation operation, and improve the energy consumption rate. We have been earnestly studying to establish the amine production process. As a result, it was found that the solid acid catalyst having a specific pore size in the disproportionation step, the solid acid catalyst subjected to the silylation treatment in the main reaction step, and the distillation operation at a specific pressure can achieve the above object. It was

【0015】即ち、本発明はメタノール、アンモニア及
びメチルアミン混合物を気相接触反応に付してメチルア
ミンを製造する方法に於いて、アンモニアとメチルアミ
ン混合物とを平均細孔径15Å以下の固体酸触媒の存在
下に於いて接触反応に付し、トリメチルアミン量を減少
させる不均化工程、及び不均化工程から得られる含メチ
ルアミン混合物の全量または一部とメタノール及びアン
モニアとをシリル化処理した固体酸触媒の存在下に於い
て接触反応に付す主反応工程、及び主反応工程から得ら
れる含メチルアミン混合物、または、主反応工程から得
られる含メチルアミン混合物と不均化工程から得られる
含メチルアミン混合物の一部を10〜25Kg/cm
・Gで蒸留し、該混合物中のトリメチルアミンを実質的
に全量塔頂よりアンモニアとの共沸混合物として留出さ
せ、これを不均化工程に供給する第一蒸留操作の結合を
特徴とするメチルアミンの製造方法に関する。
That is, the present invention provides a method for producing methylamine by subjecting a mixture of methanol, ammonia and methylamine to a gas phase catalytic reaction, wherein ammonia and methylamine mixture are mixed with a solid acid catalyst having an average pore diameter of 15 Å or less. In the presence of methane, a disproportionation step for reducing the amount of trimethylamine, and a solid obtained by silylating methanol or ammonia with all or part of the methylamine-containing mixture obtained from the disproportionation step. Main reaction step subjected to catalytic reaction in the presence of acid catalyst, and methylamine-containing mixture obtained from main reaction step, or methylamine-containing mixture obtained from main reaction step and methyl-containing step obtained from disproportionation step 10-25 kg / cm 2 of a portion of the amine mixture
Methylated by G to distill substantially all the trimethylamine in the mixture as an azeotrope with ammonia from the top of the column, and feed it to the disproportionation step, characterized by the combination of the first distillation operation. The present invention relates to a method for producing an amine.

【0016】本発明を詳細に説明する。本発明によるメ
チルアミンの製造方法の骨格は、メチルアミンの合成反
応を行う主反応工程と、主反応工程から得られる含メチ
ルアミン混合物中のアンモニアとTMAを蒸留操作の塔
頂から回収し、缶出液からは実質的にTMAを含まない
液を得る第一蒸留塔と、回収されたTMAを不均化反応
により消費する不均化工程より構成される。
The present invention will be described in detail. The skeleton of the method for producing methylamine according to the present invention comprises a main reaction step for carrying out a synthesis reaction of methylamine, and ammonia and TMA in a methylamine-containing mixture obtained from the main reaction step, which are recovered from the top of a distillation operation, It is composed of a first distillation column for obtaining a liquid containing substantially no TMA from the discharged liquid, and a disproportionation step of consuming the recovered TMA by a disproportionation reaction.

【0017】本発明でいうメチルアミン混合物とは、M
MA、DMA、TMAの混合物を、また、含メチルアミ
ン混合物とは、アンモニアやメタノールのようなメチル
アミン以外の成分を含むメチルアミン混合物と定義す
る。
The term "methylamine mixture" as used in the present invention means M
A mixture of MA, DMA and TMA is defined as a methylamine-containing mixture which is a methylamine mixture containing components other than methylamine such as ammonia and methanol.

【0018】原料であるメタノールは主反応工程の入口
に、アンモニアは不均化工程、及び/または、主反応工
程の入口にそれぞれ供給する。メチルアミンの合成反応
は一般に固体酸触媒の存在下で行われるが、本発明では
主反応工程に於いて使用する固体酸触媒をシリル化処理
した固体酸触媒に限定する。
The raw material methanol is supplied to the inlet of the main reaction step, and the ammonia is supplied to the disproportionation step and / or the inlet of the main reaction step. The synthesis reaction of methylamine is generally carried out in the presence of a solid acid catalyst, but in the present invention, the solid acid catalyst used in the main reaction step is limited to the silylated solid acid catalyst.

【0019】本発明でいうシリル化処理とは、特願平5
−185908号公報開示の方法で処理する。即ち、固
体酸触媒を酸処理、洗浄、乾燥したものを数百℃で一旦
焼成後、3〜40重量%の水を含有するように調湿し、
これを、例えばテトラメトキシオルソシリケート等の珪
素のアルコキサイドやトリメチルクロロシランを溶媒中
に溶解した液相中で処理し、表面を珪素酸化物で修飾す
る処理方法である。
The silylation treatment referred to in the present invention is Japanese Patent Application No.
The method disclosed in Japanese Patent Laid-Open No. 185908 is used. That is, the solid acid catalyst treated with acid, washed and dried is once calcined at several hundreds of degrees Celsius and then conditioned to contain 3 to 40% by weight of water.
This is a treatment method in which this is treated in a liquid phase in which alkoxide of silicon such as tetramethoxy orthosilicate or trimethylchlorosilane is dissolved in a solvent and the surface is modified with silicon oxide.

【0020】従来技術では、触媒に付加した立体的な障
害によってTMA生成反応を抑制する旨が示されている
が、本発明の目的は主反応工程に於けるTMAの生成量
を最小限に抑制し、第一蒸留操作に於いて実質的にTM
Aの全量をアンモニアとの共沸混合物として塔頂から留
出させることにより、繁雑なTMA分離操作を省略する
ことにあり、これはシリル化処理した固体酸触媒の存在
下で反応を行いTMAの生成量を所定量以下に抑制する
ことによって達成される。この理由は、シリル化処理を
行うことにより細孔径が制御され、立体障害によりTM
Aの生成反応が抑制される効果と、固体酸触媒表面がシ
リル化処理により活性点が被毒されるため、触媒表面に
於けるTMA生成反応も抑制されるという効果との双方
によるものと考えられる。
The prior art has shown that the steric hindrance added to the catalyst suppresses the TMA formation reaction, but the object of the present invention is to minimize the amount of TMA formation in the main reaction step. However, in the first distillation operation, the TM
By distilling the entire amount of A as an azeotrope with ammonia from the top of the column, a complicated TMA separation operation is omitted, which is carried out in the presence of a silylated solid acid catalyst. This is achieved by suppressing the production amount to a predetermined amount or less. The reason for this is that silylation treatment controls the pore size, and steric hindrance causes TM
It is considered to be due to both the effect of suppressing the reaction of forming A and the effect of suppressing the reaction of generating TMA on the surface of the solid acid catalyst because the active sites are poisoned by the silylation treatment. To be

【0021】シリル化処理した固体酸触媒は主反応器に
充填し、ここでメチルアミンの合成反応を行う。この際
の反応温度は250〜400℃、入口原料のN/C比は
1.5〜5.0の範囲が好ましい。反応温度が250℃
未満では、触媒の活性が低いためメタノールの転化が不
十分で効率が悪くなる。また、400℃を超えるとTM
A生成量の増加により、第一蒸留塔の塔頂からTMAを
実質的に全量を回収することができなくなる、メチルア
ミン以外の副生成物が生成するため純度の高いメチルア
ミンが得られなくなる、さらに触媒の経時劣化が早く進
行するので好ましくない。
The silylated solid acid catalyst is charged into the main reactor, where the synthetic reaction of methylamine is carried out. At this time, the reaction temperature is preferably 250 to 400 ° C., and the N / C ratio of the starting material is preferably 1.5 to 5.0. Reaction temperature is 250 ℃
If it is less than the above range, the catalyst activity is low and the conversion of methanol is insufficient, resulting in poor efficiency. Also, if the temperature exceeds 400 ° C, TM
Due to the increase in the amount of A produced, it becomes impossible to recover substantially all of TMA from the top of the first distillation column, and by-products other than methylamine are produced, so that highly pure methylamine cannot be obtained. Further, deterioration of the catalyst with time progresses rapidly, which is not preferable.

【0022】また、入口原料のN/C比を1.5未満で
は、アンモニアの不足により第一蒸留塔でTMAの全量
をアンモニアとの共沸混合物として回収することができ
なくなる。また、5.0を超えるとアンモニアの循環量
が不要に高くアンモニアを回収するエネルギーが増大
し、効率的ではないので好ましくない。
If the N / C ratio of the inlet raw material is less than 1.5, the total amount of TMA cannot be recovered as an azeotropic mixture with ammonia in the first distillation column due to lack of ammonia. Further, if it exceeds 5.0, the circulation amount of ammonia is unnecessarily high and the energy for recovering ammonia increases, which is not efficient and is not preferable.

【0023】メタノールとアンモニアからメチルアミン
を生成する反応は発熱反応であるが、反応熱により触媒
層の温度が大きく上昇すると、上述のような問題点が生
じるため、メチルアミン生成の反応熱は積極的に熱交換
して温度上昇を抑制する方がよい。このような主反応器
の型式としてはジャッケットを有する固定層反応器やイ
ンタークーラーを有する流動層反応器、多管式反応器が
使用可能であるが、除熱能力や触媒の摩耗等を考えると
多管式反応器を使用するのがより効果的である。
The reaction for producing methylamine from methanol and ammonia is an exothermic reaction. However, if the temperature of the catalyst layer rises significantly due to the heat of reaction, the above-mentioned problems occur, and therefore the heat of reaction for producing methylamine is positive. It is better to exchange heat to suppress the temperature rise. As the type of such a main reactor, a fixed bed reactor having a jacket, a fluidized bed reactor having an intercooler, and a multitubular reactor can be used, but considering the heat removal capacity and wear of the catalyst, etc. It is more effective to use a tubular reactor.

【0024】主反応工程から得られる含メチルアミン混
合物は、必要に応じて不均化工程から得られる含メチル
アミン混合物の一部と混合し、精製分離のため第一蒸留
塔に供給して、ここでTMAを実質的に全量塔頂よりア
ンモニアとの共沸混合物として留出させる。
The methylamine-containing mixture obtained from the main reaction step is optionally mixed with a part of the methylamine-containing mixture obtained from the disproportionation step and supplied to the first distillation column for purification separation. Here, substantially all of TMA is distilled off as an azeotrope with ammonia from the top.

【0025】ここで必要な条件の一つは、需要の少ない
TMAを製品として製造しないためには、第一蒸留塔に
供給する原料中のTMAのアンモニアに対する重量比率
(ここでTMAのアンモニアに対する重量比率とは、混
合物中のTMA重量/アンモニア重量×100で定義
し、以下、TMA/NH比と略記する)が13重量%
以下、好ましくは10重量%以下に抑制することであ
る。但し、主反応工程に於けるTMAの生成比率が高い
場合、上述の条件を満たすためには、それに見合う過剰
のアンモニアを循環する必要がある。しかしながら、過
剰のアンモニアを循環することは、第一蒸留塔の大型化
やアンモニア回収のためにエネルギー原単位の悪化を招
くことを意味し、事実上工業的には操業ができなくな
る。そこで、主反応工程の触媒としてシリル化処理を行
った固体酸触媒を使用すれば、主反応工程に於けるTM
Aの生成比率を7重量%以下に抑制することができ、工
業的に操業が可能な範囲で第一蒸留塔の塔頂から実質的
にTMAの全量をアンモニアとの共沸混合物として留出
させることができるのである。
One of the conditions required here is that in order not to produce TMA, which is in low demand, as a product, the weight ratio of TMA to ammonia in the raw material supplied to the first distillation column (here, the weight of TMA to ammonia is used). The ratio is defined as TMA weight / ammonia weight in the mixture × 100, and hereinafter, abbreviated as TMA / NH 3 ratio) is 13% by weight.
Hereafter, the amount is preferably suppressed to 10% by weight or less. However, when the production ratio of TMA in the main reaction step is high, it is necessary to circulate an excessive amount of ammonia to meet the above conditions. However, circulating excess ammonia means that the first distillation column is upsized and the energy consumption is deteriorated due to ammonia recovery, and it is practically impossible to operate industrially. Therefore, if a silylation-treated solid acid catalyst is used as the catalyst in the main reaction step, the TM in the main reaction step is
The production ratio of A can be suppressed to 7% by weight or less, and substantially the entire amount of TMA is distilled out as an azeotropic mixture with ammonia from the top of the first distillation column within a range where industrial operation is possible. It is possible.

【0026】PEP Report 138には、アン
モニアとTMAが210psig(約15Kg/cm
・G)に於いてアンモニア82重量%(TMA/NH
比=22重量%)で共沸組成を形成することが示されて
いる。しかしながら、第一蒸留塔で行う蒸留は、アンモ
ニア、MMA、DMA、TMA、メタノール、水等の成
分系の蒸留であり、この系でTMAを実質的に全量塔頂
よりアンモニアとの共沸混合物として留出させるために
は、原料中のTMA/NH比を13重量%以下、好ま
しくは10重量%以下としなければならないことは、本
発明者らが実験的に確認した点である。
The PEP Report 138 contains 210 psig of ammonia and TMA (about 15 Kg / cm 2
・ G) 82% by weight ammonia (TMA / NH 3
Ratio = 22% by weight) has been shown to form an azeotropic composition. However, the distillation performed in the first distillation column is a distillation of a component system of ammonia, MMA, DMA, TMA, methanol, water, etc. In this system, substantially all the amount of TMA is azeotropically mixed with ammonia from the top of the column. It is a point experimentally confirmed by the present inventors that the TMA / NH 3 ratio in the raw material must be 13% by weight or less, preferably 10% by weight or less for distilling.

【0027】二つ目に、第一蒸留塔の操作圧力を特定す
ることである。一般的にアンモニアのように沸点の低い
成分の蒸留を行う場合、圧力が高い条件の方が、高い温
度で凝縮できるため操業上は有利になるが、本発明者ら
は、25〜30Kg/cm・Gの範囲でTMAが実質
的にアンモニアと共沸組成を形成しなくなることを確認
しており、操作圧力が25Kg/cm・Gを超える
と、第一蒸留塔の塔頂からTMAの全量を留出させるこ
とができなくなり、本発明を遂行することはできない。
また10Kg/cm・G未満では塔頂の沸点が30℃
以下となり効率的ではないため、主反応器出口組成と操
業効率を考慮して10〜25Kg/cm・Gの範囲で
条件を選択する必要がある。ここに圧力単位に使用する
Kg/cm・Gはゲージ圧であることを示す。
The second is to specify the operating pressure of the first distillation column. Generally, when distilling a component having a low boiling point such as ammonia, a condition under a high pressure is advantageous in operation because it can be condensed at a high temperature, but the present inventors have found that the pressure is 25 to 30 Kg / cm. It has been confirmed that TMA does not substantially form an azeotropic composition with ammonia in the range of 2 · G, and when the operating pressure exceeds 25 kg / cm 2 · G, the TMA from the top of the first distillation column The whole amount cannot be distilled, and the present invention cannot be carried out.
If it is less than 10 kg / cm 2 · G, the boiling point at the top of the column is 30 ° C.
Since the following is not efficient, it is necessary to select the conditions within the range of 10 to 25 Kg / cm 2 · G in consideration of the composition of the outlet of the main reactor and the operation efficiency. Here, Kg / cm 2 · G used as a pressure unit indicates a gauge pressure.

【0028】以上の条件を満たした上で第一蒸留塔の操
作を行えば、実質的にTMAの全量をアンモニアとの共
沸組成物として塔頂から留出させることができ、缶出液
からは実質的にTMAを含まない含メチルアミン混合物
を回収することができる。従って、従来の製造方法では
TMAの分離及び回収のために必要であった煩雑な抽出
蒸留操作が不要となり、これに伴って抽出水も不要とな
るため、エネルギー原単位の向上や排水量の削減等さま
ざまな効果が得られるのである。
If the first distillation column is operated after satisfying the above conditions, substantially the entire amount of TMA can be distilled off from the top of the column as an azeotropic composition with ammonia. Can recover a methylamine-containing mixture that is substantially free of TMA. Therefore, in the conventional manufacturing method, the complicated extractive distillation operation required for the separation and recovery of TMA is not necessary, and the extracted water is not necessary, so that the energy consumption rate is improved and the amount of discharged water is reduced. Various effects can be obtained.

【0029】第一蒸留塔の塔頂から得られる含メチルア
ミン混合物は、必要に応じてアンモニアと混合し、固体
酸触媒を充填した不均化反応器に供給する。ここでは、
下記(4)〜(6)式に従って不均化反応を進め、主反
応工程に於けるTMAの生成見合い量のTMAを消費す
る。
The methylamine-containing mixture obtained from the top of the first distillation column is optionally mixed with ammonia and supplied to a disproportionation reactor filled with a solid acid catalyst. here,
The disproportionation reaction proceeds according to the following equations (4) to (6), and the amount of TMA produced in the main reaction step is consumed.

【0030】 [0030]

【0031】ここで使用する固体酸触媒としては、平均
細孔径15Å以下のものとし、ゼオライトが特に好まし
い。この理由は、平均細孔径15Åを超えるとエチルア
ミンやアセトニトリルといった副生成物が生成しやす
く、メチルアミンの純度が低下する。また、不均化反応
工程で使用する固体酸触媒の役割は主反応工程で使用す
る触媒の役割とは異なり、TMAを消費することである
ため、触媒の平均細孔径はTMAが立体的な障害を受け
ないもの、好ましくは5Åを超えるものを用いる。不均
化反応は主反応工程とは逆に総合的にはわずかな吸熱反
応であるため、反応器の型式には特に制限はなく、同様
に通常の固定層反応器や流動層反応器等が好適に使用可
能である。
The solid acid catalyst used here has an average pore diameter of 15 Å or less, and zeolite is particularly preferable. The reason for this is that when the average pore diameter exceeds 15 Å, by-products such as ethylamine and acetonitrile are likely to be generated, and the purity of methylamine is reduced. Further, the role of the solid acid catalyst used in the disproportionation reaction step is to consume TMA, unlike the role of the catalyst used in the main reaction step. Therefore, the average pore diameter of the catalyst is sterically hindered by TMA. Those that do not undergo the treatment, preferably those that exceed 5Å are used. Contrary to the main reaction step, the disproportionation reaction is a slight endothermic reaction overall, so there is no particular limitation on the type of reactor, and similarly, a fixed bed reactor, a fluidized bed reactor, or the like can be used. It can be preferably used.

【0032】本発明で不均化反応は、反応温度280〜
450℃の範囲が好ましい。反応温度が280℃未満で
は、触媒の活性が不十分であり、また450℃を超える
と副反応が著しくなることと触媒の経時劣化が早く進行
するので好ましくない。
In the present invention, the disproportionation reaction is carried out at a reaction temperature of 280 to 280.
The range of 450 ° C is preferred. If the reaction temperature is lower than 280 ° C., the activity of the catalyst is insufficient, and if it exceeds 450 ° C., side reactions become remarkable and deterioration of the catalyst with time progresses rapidly, which is not preferable.

【0033】通常は、できるだけ低い温度で操業を行っ
た方が、上述のように副生成物、触媒の劣化及びエネル
ギー面で有利であるが、しかしながら、本発明ではTM
Aを製品として製造しないため、物質収支上不均化反応
工程に於いて、主反応工程で新たに生成するTMA量と
同量を消費する必要がある。即ち、反応条件を上述の範
囲で自由に選定できるものではなく、主反応工程で多量
のTMAが生成すると、不均化工程に於いてそれだけ多
量のTMAを消費しなければならない。これは反応温度
のより高い条件で不均化反応を行わなければならないこ
とを意味し、従って、主反応工程に於けるTMAの生成
量を最小限に抑制することは、不均化反応をも有利な条
件で進めることにつながるのである。不均化反応工程か
ら得られた含メチルアミン混合物の全量もしくは一部
は、主反応工程にリサイクルされ、主反応工程の原料の
一部として利用される。
Generally, it is advantageous to operate at a temperature as low as possible in terms of by-products, catalyst deterioration and energy as described above, however, in the present invention, TM is used.
Since A is not manufactured as a product, it is necessary to consume the same amount of TMA newly generated in the main reaction step in the disproportionation reaction step in terms of mass balance. That is, the reaction conditions cannot be freely selected within the above range, and if a large amount of TMA is produced in the main reaction step, that much amount of TMA must be consumed in the disproportionation step. This means that the disproportionation reaction must be carried out under the condition of higher reaction temperature. Therefore, minimizing the production amount of TMA in the main reaction step also causes the disproportionation reaction. It will lead to favorable conditions. All or part of the methylamine-containing mixture obtained from the disproportionation reaction step is recycled to the main reaction step and used as part of the raw material for the main reaction step.

【0034】以上のような一連の操作により、第一蒸留
塔の缶出液からはTMAを含まないMMA、DMA、未
反応のメタノール、副生成物の水の混合物を回収するこ
とができる。これら混合物の精製分離は公知の方法に従
って、第二蒸留塔に於いて、MMAとDMAの混合物を
塔頂から留出、缶出液からはメタノールと水を回収し、
第三蒸留塔に於いてMMAとDMAの分離を行って製品
として回収すればよい。
By the series of operations described above, a mixture of MMA containing no TMA, DMA, unreacted methanol and water as a by-product can be recovered from the bottoms of the first distillation column. Purification and separation of these mixtures according to a known method, a mixture of MMA and DMA is distilled from the top of the second distillation column, and methanol and water are recovered from the bottom liquid,
MMA and DMA may be separated in the third distillation column and recovered as a product.

【0035】[0035]

【実施例】以下、実施例により本発明を具体的に説明す
る。なお、%は特記しないかぎり重量%で表す。 実施例1 平均細孔径10Åのモルデナイトを2N塩酸で酸処理洗
浄後、水分を10%含有するように調湿し、1.5mo
l%テトラエトキシシリケートのトルエン溶液中で、テ
トラエトキシシリケートとモルデナイトの割合が0.3
3mol/kg−モルデナイトとなる量でシリル化処理
を行った。この触媒を主反応器に2.5kg充填し、ま
た不均化反応器には上述の天然産モルデナイトを2N塩
酸で酸処理洗浄を行ったのみの触媒を充填した。主反応
器、第一蒸留塔、不均化反応器を図1に示すように接続
し、系内の圧力を18Kg/cm・G、主反応器温度
300〜305℃、不均化反応器温度335〜340℃
とし、メタノールを1000g/hの速度で供給、主反
応器入口に於けるN/C比が2.5となるようにアンモ
ニア流量を調節しつつ、連続で反応を行い、定常状態を
待った。反応開始後、約40時間で定常状態に到達し、
その際の各ラインの流体流量を測定したところ表1に示
す結果が得られた。200時間経過後も流体流量に大き
な変動はなく、第一蒸留塔の缶出液からはTMAを含有
しないメチルアミン混合物を安定的に回収することがで
きた。ガスクロマトグラフィーで缶出液の組成分析を行
ったところ、TMAの含有量は100ppm以下であっ
た。また、主反応工程に於けるTMA生成比率は4.3
%であった。
EXAMPLES The present invention will be specifically described below with reference to examples. In addition,% is expressed by weight unless otherwise specified. Example 1 Mordenite having an average pore diameter of 10 Å was acid-washed with 2N hydrochloric acid, and then conditioned to contain 10% of water, and 1.5 mo
In a toluene solution of 1% tetraethoxysilicate, the ratio of tetraethoxysilicate and mordenite is 0.3.
The silylation treatment was performed in an amount of 3 mol / kg-mordenite. The main reactor was charged with 2.5 kg of this catalyst, and the disproportionation reactor was charged with the catalyst obtained by only acid-washing the above-mentioned natural mordenite with 2N hydrochloric acid. The main reactor, the first distillation column, and the disproportionation reactor are connected as shown in FIG. 1, the pressure in the system is 18 kg / cm 2 · G, the main reactor temperature is 300 to 305 ° C., the disproportionation reactor. Temperature 335-340 ° C
Then, methanol was supplied at a rate of 1000 g / h, the ammonia flow rate was adjusted so that the N / C ratio at the inlet of the main reactor was 2.5, the reaction was continuously performed, and a steady state was awaited. About 40 hours after starting the reaction, a steady state is reached,
When the fluid flow rate of each line at that time was measured, the results shown in Table 1 were obtained. The fluid flow rate did not change significantly even after 200 hours, and the TMA-free methylamine mixture could be stably recovered from the bottoms of the first distillation column. When the composition of the bottoms was analyzed by gas chromatography, the TMA content was 100 ppm or less. The TMA production ratio in the main reaction step is 4.3.
%Met.

【0036】実施例2 系内の圧力を13Kg/cm・Gに変更した以外は、
実施例1と同様の条件で連続反応を行い定常状態を待っ
た。反応開始後、約55時間で定常状態に到達し、その
際の各ラインの流体流量を測定したところ表2に示す結
果が得られた。160時間経過後も流体流量に大きな変
動はなく、第一蒸留塔の缶出液からはTMAを含有しな
いメチルアミン混合物を安定的に回収することができ
た。ガスクロマトグラフィーで缶出液の組成分析を行っ
たところ、TMAの含有量は100ppm以下であっ
た。また、主反応工程に於けるTMA生成比率は3.9
%であった。
Example 2 Except that the pressure in the system was changed to 13 Kg / cm 2 · G,
Continuous reaction was carried out under the same conditions as in Example 1, and a steady state was awaited. A steady state was reached about 55 hours after the start of the reaction, and the fluid flow rate of each line at that time was measured. The results shown in Table 2 were obtained. Even after 160 hours, the fluid flow rate did not significantly change, and the methylamine mixture containing no TMA could be stably recovered from the bottoms of the first distillation column. When the composition of the bottoms was analyzed by gas chromatography, the TMA content was 100 ppm or less. Further, the TMA production ratio in the main reaction step is 3.9.
%Met.

【0037】実施例3 系内の圧力を23Kg/cm・Gに変更した以外は、
実施例1と同様の条件で連続反応を行い定常状態を待っ
た。反応開始後、約70時間で定常状態に到達し、その
際の各ラインの流体流量を測定したところ表3に示す結
果が得られた。240時間経過後も流体流量に大きな変
動はなく、第一蒸留塔の缶出液からはTMAを含有しな
いメチルアミン混合物を安定的に回収することができ
た。ガスクロマトグラフィーで缶出液の組成分析を行っ
たところ、TMAの含有量は320ppmであった。ま
た、主反応工程に於けるTMA生成比率は4.6%であ
った。
Example 3 Except that the pressure in the system was changed to 23 Kg / cm 2 · G,
Continuous reaction was carried out under the same conditions as in Example 1, and a steady state was awaited. A steady state was reached about 70 hours after the start of the reaction, and when the fluid flow rate of each line at that time was measured, the results shown in Table 3 were obtained. The fluid flow rate did not change significantly after 240 hours, and the TMA-free methylamine mixture could be stably recovered from the bottoms of the first distillation column. When the composition of the bottoms was analyzed by gas chromatography, the TMA content was 320 ppm. In addition, the TMA production ratio in the main reaction step was 4.6%.

【0038】比較例1 系内の圧力を30Kg/cm・Gに変更した以外は、
実施例1と同様の条件で連続反応を行い定常状態を待っ
た。反応開始後、約65時間で定常状態に到達し、その
際の各ラインの流体流量を測定したところ表4に示す結
果が得られた。240時間経過後も流体流量に大きな変
動はなく、第一蒸留塔の缶出液からTMAが検出され
た。また、主反応工程に於けるTMA生成比率は4.5
%であった。
Comparative Example 1 Except that the pressure in the system was changed to 30 kg / cm 2 · G,
Continuous reaction was carried out under the same conditions as in Example 1, and a steady state was awaited. A steady state was reached about 65 hours after the start of the reaction, and when the fluid flow rate of each line at that time was measured, the results shown in Table 4 were obtained. The fluid flow rate did not change significantly even after 240 hours, and TMA was detected in the bottoms of the first distillation column. In addition, the TMA production ratio in the main reaction step is 4.5.
%Met.

【0039】比較例2 主反応器に充填する触媒として平均細孔径10Åのモル
デナイトを2N塩酸で酸処理洗浄行ったのみでシリル化
処理しない触媒を充填し、実施例1と同様の条件とし、
連続反応を行い定常状態を待った。反応開始後、約40
時間で定常状態に到達し、その際の各ラインの流体流量
を測定したところ表5に示す結果が得られた。240時
間経過後も流体流量に大きな変動はなく、第一蒸留塔の
缶出液からTMAが検出された。また、主反応工程に於
けるTMA生成比率は20.4%であった。
Comparative Example 2 As a catalyst to be charged in the main reactor, mordenite having an average pore diameter of 10 Å was acid-washed with 2N hydrochloric acid, and was charged with a catalyst not to be silylated.
A continuous reaction was performed and a steady state was awaited. After starting the reaction, about 40
When the steady state was reached in time and the fluid flow rate of each line at that time was measured, the results shown in Table 5 were obtained. The fluid flow rate did not change significantly even after 240 hours, and TMA was detected in the bottoms of the first distillation column. In addition, the TMA production ratio in the main reaction step was 20.4%.

【0040】実施例4 天然産ゼオライト(モルデナイト含有率約70%)を2
N塩酸で酸処理洗浄後、水分を10%含有するように調
湿し、2.4mol%テトラメトキシシリケートのトル
エン溶液中で、テトラメトキシシリケートとゼオライト
の割合が0.5mol/kg−ゼオライトとなる量でシ
リル化処理を行った。この触媒を主反応器に2.5kg
充填し、また不均化反応器には上述の天然産ゼオライト
を2N塩酸で酸処理洗浄を行ったのみの触媒を充填し
た。系内の圧力を20Kg/cm・G、主反応器温度
295〜300℃、不均化反応器温度320〜325℃
とし、メタノールを1000g/hの速度で供給、主反
応器入口に於けるN/C比が2.0となるようにアンモ
ニア流量を調節しつつ、実施例1と同様にして連続反応
を行い、定常状態を待った。反応開始後、約30時間で
定常状態に到達し、その際の各ラインの流体流量を測定
したところ表6に示す結果が得られた。180時間経過
後も流体流量に大きな変動はなく、第一蒸留塔の缶出液
からはTMAを含有しないメチルアミン混合物を安定的
に回収することができた。ガスクロマトグラフィーで缶
出液の組成分析を行ったところ、TMAの含有量は20
0ppm以下であった。また、主反応工程に於けるTM
A生成比率は3.2%であった。
Example 4 Two natural zeolites (mordenite content of about 70%) were added.
After acid treatment and washing with N hydrochloric acid, the moisture was adjusted to contain 10% of water, and in a toluene solution of 2.4 mol% tetramethoxysilicate, the ratio of tetramethoxysilicate and zeolite was 0.5 mol / kg-zeolite. The amount of silylation treatment was performed. 2.5 kg of this catalyst in the main reactor
The catalyst was charged and the disproportionation reactor was charged with the catalyst obtained by only acid-washing the above natural zeolite with 2N hydrochloric acid. Pressure in the system is 20 Kg / cm 2 · G, main reactor temperature 295 to 300 ° C, disproportionation reactor temperature 320 to 325 ° C
Then, methanol was supplied at a rate of 1000 g / h, the ammonia flow rate was adjusted so that the N / C ratio at the main reactor inlet was 2.0, and a continuous reaction was carried out in the same manner as in Example 1. Waited for steady state. A steady state was reached about 30 hours after the start of the reaction, and when the fluid flow rate of each line at that time was measured, the results shown in Table 6 were obtained. The fluid flow rate did not change significantly after 180 hours, and the TMA-free methylamine mixture could be stably recovered from the bottoms of the first distillation column. When the composition of the bottom liquid was analyzed by gas chromatography, the TMA content was 20.
It was 0 ppm or less. Also, TM in the main reaction process
The A production ratio was 3.2%.

【0041】[0041]

【表1】 [Table 1]

【0042】[0042]

【表2】 [Table 2]

【0043】[0043]

【表3】 [Table 3]

【0044】[0044]

【表4】 [Table 4]

【0045】[0045]

【表5】 [Table 5]

【0046】[0046]

【表6】 [Table 6]

【0047】[0047]

【発明の効果】以上詳細に説明した如く、本発明によれ
ば、第一蒸留塔の原料である含メチルアミン混合物中の
TMAを実質的に全量塔頂よりアンモニアとの共沸混合
物として留出させ、缶出液からは実質的にTMAを含有
しないメチルアミン混合物を回収することができる。従
来法の如き繁雑な操作を行ってTMAの分離を行う必要
がない。従って、プロセスを簡略化できると共に、TM
A分離工程とTMAタンクの省略及び第二蒸留塔(脱水
塔)の縮小化による設備費の削減、抽出水の省略とこれ
に伴う第二蒸留塔(脱水塔)に於けるエネルギー原単位
の向上による変動費の削減、及び環境面に於ける排水量
の低減等数多くの利点が得られる。これにより、需要の
高いMMAとDMAの回収比率を高く、かつ安価に効率
的に回収することができるため、その効果は大きい。
As described in detail above, according to the present invention, substantially all the amount of TMA in the methylamine-containing mixture which is the raw material of the first distillation column is distilled from the top of the column as an azeotropic mixture with ammonia. Then, the methylamine mixture containing substantially no TMA can be recovered from the bottom liquid. It is not necessary to separate TMA by performing a complicated operation as in the conventional method. Therefore, the process can be simplified and the TM
Equipment cost reduction by omission of A separation step and TMA tank and reduction of the size of the second distillation column (dehydration tower), omission of extracted water and improvement of energy consumption per unit in the second distillation column (dehydration tower) There are many advantages such as reduction of variable costs and reduction of wastewater from the environmental aspect. As a result, MMA and DMA, which are in high demand, can be efficiently recovered at a high recovery ratio at a low cost, which is a great effect.

【0048】[0048]

【図面の簡単な説明】[Brief description of drawings]

【図1】 メチルアミン製造の工程図FIG. 1 Process diagram of methylamine production

【符号の説明】[Explanation of symbols]

ア 主反応器 イ 第一蒸留塔 ウ 不均化反応器 1 メタノール 2 アンモニア 3 主反応器原料 4 含メチルアミン混合物 5 第一蒸留塔留出液 6 第一蒸留塔缶出液 7 不均化反応器原料 A main reactor a first distillation tower c disproportionation reactor 1 methanol 2 ammonia 3 main reactor raw material 4 methylamine-containing mixture 5 first distillation tower distillate 6 first distillation tower can 7 disproportionation reaction Raw material

───────────────────────────────────────────────────── フロントページの続き (72)発明者 岩永 徳幸 山口県下関市彦島迫町七丁目1番1号 三 井東圧化学株式会社内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Noriyuki Iwanaga 7-1, 1-1 Hikoshimasako-cho, Shimonoseki City, Yamaguchi Prefecture Mitsui Toatsu Chemicals, Inc.

Claims (7)

【特許請求の範囲】[Claims] 【請求項1】 メタノール、アンモニア及びメチルア
ミン混合物を気相接触反応に付してメチルアミンを製造
する方法に於いて、アンモニアとメチルアミン混合物と
を平均細孔径15Å以下の固体酸触媒の存在下に於いて
接触反応に付し、トリメチルアミン量を減少させる不均
化工程、及び不均化工程から得られる含メチルアミン混
合物の全量または一部とメタノール及びアンモニアとを
シリル化処理した固体酸触媒の存在下に於いて接触反応
に付す主反応工程、及び主反応工程から得られる含メチ
ルアミン混合物、または、主反応工程から得られる含メ
チルアミン混合物と不均化工程から得られる含メチルア
ミン混合物の一部を10〜25Kg/cm・Gで蒸留
し、該混合物中のトリメチルアミンを実質的に全量塔頂
よりアンモニアとの共沸混合物として留出させ、これを
不均化工程に供給する第一蒸留操作の結合を特徴とする
メチルアミンの製造方法。
1. A method for producing methylamine by subjecting a mixture of methanol, ammonia and methylamine to a gas phase catalytic reaction, wherein the mixture of ammonia and methylamine is present in the presence of a solid acid catalyst having an average pore size of 15Å or less. Of the solid acid catalyst obtained by subjecting the disproportionation step of reducing the amount of trimethylamine to a catalytic reaction in the above step, and all or a part of the methylamine-containing mixture obtained from the disproportionation step and methanol and ammonia to silylation treatment. Of the main reaction step of subjecting to a catalytic reaction in the presence, and the methylamine-containing mixture obtained from the main reaction step, or the methylamine-containing mixture obtained from the main reaction step and the methylamine-containing mixture obtained from the disproportionation step some were distilled at 10~25Kg / cm 2 · G, and substantially ammonia than the total amount the top of trimethylamine in the mixture Distill the azeotropic mixture, method for producing methylamines, wherein binding of the first distillation operation and supplies it to the disproportionation step.
【請求項2】 主反応工程の入口に於ける原料の窒素
/炭素のモル比が1.5〜5.0の範囲である請求項1
に記載のメチルアミンの製造方法。
2. The nitrogen / carbon molar ratio of the raw material at the inlet of the main reaction step is in the range of 1.5 to 5.0.
The method for producing methylamine according to 1.
【請求項3】 主反応工程に於ける反応温度が250
〜400℃の範囲である請求項1に記載のメチルアミン
の製造方法。
3. The reaction temperature in the main reaction step is 250.
The method for producing methylamine according to claim 1, wherein the temperature is in the range of 400 ° C to 400 ° C.
【請求項4】 不均化工程に於ける反応温度が280
〜450℃、入口原料の窒素/炭素のモル比が5以上の
範囲である請求項1記載のメチルアミンの製造方法。
4. The reaction temperature in the disproportionation step is 280.
The method for producing methylamine according to claim 1, wherein the inlet material has a nitrogen / carbon molar ratio in the range of from 5 to 450 ° C.
【請求項5】 シリル化処理した固体酸触媒が、液相
中シリル化剤で処理したゼオライトである請求項1記載
のメチルアミンの製造方法。
5. The method for producing methylamine according to claim 1, wherein the silylation-treated solid acid catalyst is zeolite treated with a silylating agent in a liquid phase.
【請求項6】 シリル化処理した固体酸触媒が、液相
中シリル化剤で処理したモルデナイトである請求項1記
載のメチルアミンの製造方法。
6. The method for producing methylamine according to claim 1, wherein the silylation-treated solid acid catalyst is mordenite treated with a silylating agent in a liquid phase.
【請求項7】 主反応工程の反応器として多管式反応
器を使用することを特徴とする請求項1記載のメチルア
ミンの製造方法。
7. The method for producing methylamine according to claim 1, wherein a multitubular reactor is used as a reactor in the main reaction step.
JP30589894A 1993-12-28 1994-12-09 Method for producing methylamine Expired - Lifetime JP3213497B2 (en)

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Application Number Priority Date Filing Date Title
JP33550193 1993-12-28
JP5-335501 1993-12-28
JP30589894A JP3213497B2 (en) 1993-12-28 1994-12-09 Method for producing methylamine

Publications (2)

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JPH07233125A true JPH07233125A (en) 1995-09-05
JP3213497B2 JP3213497B2 (en) 2001-10-02

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ID=26564489

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Country Status (1)

Country Link
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007161637A (en) * 2005-12-13 2007-06-28 Mitsui Chemicals Inc Method for producing methylamine

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007161637A (en) * 2005-12-13 2007-06-28 Mitsui Chemicals Inc Method for producing methylamine

Also Published As

Publication number Publication date
JP3213497B2 (en) 2001-10-02

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