JPS6227583A - Method for electrolytically dimerizing acrylonitrile - Google Patents

Abstract

PURPOSE:To electrolytically dimerize acrylonitrile in a high yield in an electrolytic cell having a single chamber by specifying the proportion of an oil phase in an emulsified electrolytic soln. contg. a specified electrically conductive supporting salt and acrylonitrile and by carrying out electrolysis with nickel steel as the anode. CONSTITUTION:Nickel steel having an electrically conductive surface is used as the anode in an electrolytic cell having a single chamber. An emulsion contg. an electrically conductive supporting salt consisting of an alkali metallic salt and a quat. ammonium salt and acrylonitrile so as to regulate the proportion of an oil phase to 6-30wt% is prepd. as an electrolytic soln. This electrolytic soln. is fed to the electrolytic cell and circulated. In the cell, the acrylonitrile is electrolytically dimerized to produce adiponitrile. The nickel steel anode is hardly consumed and gathers little rust, so it is easily handled. By this method, the yield of adiponitrile can be kept stably high.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、アクリロニトリル（以下、ＡＮと略記する）
を電解三量化してアジポニトリル（以下、ＡＤＮと略記
する）を製造する方法に関するものである。さらに詳し
くは、ＡＮ、水および電導性支持塩を含む電解液を単一
室電解槽に通液し、ＡＮを電解三量化することによって
ＡＤＮを製造する方法に関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention relates to acrylonitrile (hereinafter abbreviated as AN)
The present invention relates to a method for producing adiponitrile (hereinafter abbreviated as ADN) by electrolytically trimerizing. More specifically, the present invention relates to a method for producing ADN by passing an electrolytic solution containing AN, water, and a conductive supporting salt into a single-chamber electrolytic cell, and electrolytically trimerizing AN.

ＡＤＮは合成繊維、プラスチックとして重要なナイロン
６６の中間原料である。ADN is an intermediate raw material for nylon 66, which is important as a synthetic fiber and plastic.

（従来の技術） ＡＮの電解二世化によるＡＤＮの製造は、すでに工業化
されているが、その方法は隔膜を用いたものである。隔
膜を用いないと陽極の腐食が激しく、また、陽極におい
てＡＮが酸化されてＡＮＤ準のＡＤＨ選択率が低くなる
などの理由からである。(Prior Art) The production of ADN by electrolytic conversion of AN has already been industrialized, but this method uses a diaphragm. This is because if a diaphragm is not used, the anode will be severely corroded, and AN will be oxidized at the anode, resulting in a low AND quasi-ADH selectivity.

しかしながら、隔膜、実質的には陽イオン交換膜を用い
る電解方法は、隔膜の電気抵抗などによる電力の損失が
極めて大きく、また、隔膜自体の経済的負担が大きいな
どの欠点を有している。However, the electrolysis method using a diaphragm, essentially a cation exchange membrane, has drawbacks such as extremely large power loss due to electrical resistance of the diaphragm, and a large economic burden on the diaphragm itself.

したがって、隔膜を用いない単一室電解槽においてＡＮ
の電解二世化を行う方法が種々提案されている。Therefore, in a single-chamber electrolyzer without a diaphragm, AN
Various methods have been proposed for performing electrolytic conversion.

例えば、酸化物陽極を用い、電導性支持塩としてアルカ
リ金属塩と第４級アンモニウム塩を含む電解液を電解す
る方法（特公昭５２−３８０１３号公報入電導性支持塩
として高濃度の第４級アンモニウム塩のみを含む電解液
を電解する方法（特公昭４５−３０８０４号公！１）な
どが知られている。しかしながら、前者の方法は、陽極
の腐食が大きい欠点を有しており、また、後者の方法は
、高濃度の４級アンモニウムイオンが陽極で酸化される
欠点がある。For example, a method of electrolyzing an electrolytic solution containing an alkali metal salt and a quaternary ammonium salt as a conductive supporting salt using an oxide anode (see Japanese Patent Publication No. 52-38013). A method of electrolyzing an electrolytic solution containing only ammonium salts (Japanese Patent Publication No. 45-30804! 1) is known. However, the former method has the drawback of significant corrosion of the anode; The latter method has the disadvantage that a high concentration of quaternary ammonium ions is oxidized at the anode.

さらに、これらの方法は、いずれも電解液中のＡＮやＡ
ＤＮの濃度、すなわち、有機物の濃度が３０〜５０重量
％と高い。単一室電解槽での電解では、一般に有機物濃
度が高くなると、有機物が陽極酸化を受けやすくなり、
ＡＤＮの収率の低下を引き起こす。Furthermore, these methods all contain AN and A in the electrolyte.
The concentration of DN, that is, the concentration of organic matter is as high as 30 to 50% by weight. In electrolysis in a single-chamber electrolyzer, generally as the concentration of organic matter increases, the organic matter becomes more susceptible to anodic oxidation;
This causes a decrease in the yield of ADN.

この点を克服するために、電解液中の有機物濃度を下げ
て電解する方１法が種々提案されている。In order to overcome this point, various methods have been proposed in which electrolysis is performed by lowering the concentration of organic matter in the electrolytic solution.

例えば、陽極に鉛を用い、電解液中の有機物濃度を２〜
１２％重量％とする方法（特公昭５１〜１８９３１号公
報）、炭素鋼を陽極に用い、有機物濃度を２０重量％以
下、好ましくは５重量％以下とする方法（特公昭５８−
３７３９６号公報）がある。しかしながら、前者の方法
は、鉛陽極面に絶縁性沈着物が付着しやすく、電解電圧
の上昇を引き起こすので、定期的に陽極を洗浄する必要
がある。そして、鉛陽極は酸素過電圧が高いため、有機
物が酸化されやすく、必然的に電解液中の有機物濃度を
低くしなければならない。For example, if lead is used for the anode and the organic matter concentration in the electrolyte is
12% by weight (Japanese Patent Publication No. 51-18931), a method in which carbon steel is used as an anode and the organic matter concentration is 20% by weight or less, preferably 5% by weight or less (Japanese Patent Publication No. 58-1893).
37396). However, in the former method, insulating deposits tend to adhere to the surface of the lead anode, causing an increase in electrolytic voltage, and therefore the anode needs to be cleaned periodically. Furthermore, since the lead anode has a high oxygen overvoltage, organic substances are easily oxidized, and the concentration of organic substances in the electrolyte must necessarily be lowered.

また、後者の炭素鋼を陽極とする場合、酸素過電圧は鉛
より低く、陽極での絶縁性沈着物の付着は少ないが、炭
素鋼が少しづつ腐食し、溶出した鉄イオンが陰極表面上
に電着し、水素を発生させやすい欠点がある。この溶出
鉄イオンによる水素発生を抑制するため重金属封鎖剤を
添加する方法（特開昭４９−９２０２１号公報、特開昭
５０−１２６６１９号公報）が提案されているが、なお
水素抑制の効果は充分ではない。In addition, when the latter carbon steel is used as an anode, the oxygen overvoltage is lower than that of lead, and there is less insulating deposits on the anode, but the carbon steel corrodes little by little and the eluted iron ions form a charge on the cathode surface. The drawback is that it tends to accumulate and generate hydrogen. A method of adding a heavy metal sequestering agent to suppress hydrogen generation due to this eluted iron ion has been proposed (Japanese Patent Application Laid-Open No. 49-92021, Japanese Patent Application Laid-open No. 126619-1982), but the hydrogen suppression effect remains. Not enough.

また、水素発生および電解電圧の安定維持のために電解
液をキレート樹脂で処理する方法（特開昭５９−５９８
８８号公報）も提案されており、この方法では、ニッケ
ル５重量％を含有したＮｉ鋼などの合金鋼も使用できる
ことが知られている。In addition, a method of treating the electrolyte with a chelate resin in order to generate hydrogen and maintain stable electrolytic voltage (Japanese Patent Laid-Open No. 59-598
No. 88) has also been proposed, and it is known that alloy steel such as Ni steel containing 5% by weight of nickel can also be used in this method.

このように単一室電解槽でＡＮを電解二世化する従来技
術では、陽極での有機物の酸化を抑制するために、電解
液中の有機物濃度を低（する必要があり、有機物濃度は
好ましくは１０重量％以下である。In this conventional technology for electrolyzing AN in a single-chamber electrolyzer, in order to suppress the oxidation of organic matter at the anode, it is necessary to reduce the concentration of organic matter in the electrolyte. is 10% by weight or less.

また、陽極の腐食が無視できず、溶出した金属イオンの
除去や、陽極の定期的な更新など繁雑な操作を必要とし
ている。Furthermore, corrosion of the anode cannot be ignored, requiring complicated operations such as removing eluted metal ions and periodically renewing the anode.

（発明が解決しようとする問題点） 一方、工業的なＡＮの電解二量化によるＡＤＮの製造で
は、ＡＮ、水および電導性支持塩を含む電解液が電解液
タンクから電解槽に循環する方法がとられる。電解反応
で消費したＡＮは連続的に補給され、生成したＡＤＮは
、電解液の一部を抜き出して、電導性支持塩を含む水相
と分離して回収される。(Problems to be Solved by the Invention) On the other hand, in the industrial production of ADN by electrolytic dimerization of AN, there is a method in which an electrolytic solution containing AN, water, and a conductive supporting salt is circulated from an electrolytic solution tank to an electrolytic cell. Be taken. The AN consumed in the electrolytic reaction is continuously replenished, and the generated ADN is recovered by extracting a portion of the electrolytic solution and separating it from the aqueous phase containing the conductive supporting salt.

このＡＤＮの分離、回収を容易にするため、電解液は油
相と水相からなるエマルジョンであることが好ましい。In order to facilitate the separation and recovery of this ADN, the electrolytic solution is preferably an emulsion consisting of an oil phase and an aqueous phase.

均一溶液でも電解は実施できるが、生成したＡＤＮを電
導性支持塩と分離して回収すするのに複雑な方法が必要
である。エマルジョンであるときは、エマルジョンをデ
カンタ−などに送り、油相と水相に分離すれば、その油
相からＡＤＮが容易に回収でき、電導性支持塩を含む水
相は、そのまま電解液タンクに戻すことができる。Although electrolysis can be carried out in homogeneous solutions, complex methods are required to separate and recover the produced ADN from the conductive supporting salt. If it is an emulsion, ADN can be easily recovered from the oil phase by sending the emulsion to a decanter or the like and separating it into an oil phase and an aqueous phase, and the aqueous phase containing the conductive supporting salt can be directly transferred to the electrolyte tank. It can be returned.

このように電解液がエマルジョンである連続的な電解運
転において、電解液中の有機物濃度が低いと、すなわち
、より直接的にはエマルジョンの油相比率が低いと、生
成したＡＤＮを電解液から必要量分離、回収するために
は、デカンタ−などに大量の電解液を送り、必要量の油
相を分離し、大きな比率を占める水相を電解液タンクに
戻す必要がある。また、デカンタ−での油相と水相の分
離には滞留時間も必要であるから、デカンタ−の容量が
大きくなる欠点がある。したがって、ＡＮの電解二世化
によるＡＤＮの製造の工業的な実施においては、ＡＤＮ
の分離、回収のためには、エマルジョンの油相比率が冑
い方が好ましい。In this continuous electrolysis operation where the electrolyte is an emulsion, if the concentration of organic matter in the electrolyte is low, or more directly, if the oil phase ratio of the emulsion is low, the generated ADN will be required from the electrolyte. In order to separate and recover the amount, it is necessary to send a large amount of electrolyte to a decanter or the like, separate the necessary amount of oil phase, and return the aqueous phase, which accounts for a large proportion, to the electrolyte tank. Furthermore, since a residence time is required for separation of the oil phase and the aqueous phase in the decanter, there is a drawback that the capacity of the decanter becomes large. Therefore, in the industrial implementation of ADN production by electrolytic conversion of AN, ADN
In order to separate and recover the emulsion, it is preferable that the oil phase ratio of the emulsion is low.

また、連続的な運転において、ＡＤＮの高く安定した収
率を得るためには、電解液エマルジョンの油相比率や油
相中のＡ　Ｎ　？Ｘ度などの電解液組成を最適組成に一
定に維持することが重要である。In addition, in order to obtain a high and stable yield of ADN in continuous operation, the oil phase ratio of the electrolyte emulsion and the A N ? It is important to maintain the electrolyte composition constant at an optimum composition such as X degrees.

このような運転において、電解液の油相比率が低いと、
必要量ＡＤＮを電解液から回収する際、その油相の抜き
出し量のわずかの変動に対して、電解液中の油相比率の
変動が大きい。この油相比率の変動は、また油相中のＡ
Ｎ濃度を変動させ、電解液の組成を乱し、安定したＡＤ
Ｎの収率を得ることを困難にする。In such operation, if the oil phase ratio of the electrolyte is low,
When recovering the required amount of ADN from the electrolytic solution, the oil phase ratio in the electrolytic solution fluctuates greatly with respect to a slight variation in the amount of the extracted oil phase. This variation in oil phase ratio also causes A in the oil phase.
By varying the N concentration and disturbing the composition of the electrolyte, stable AD can be achieved.
making it difficult to obtain a yield of N.

したがって、ＡＮの電解三量化の工業化において、陽極
での有機物の酸化が大きくならない範囲では、電解液中
のエマルジョンの油相比率が高い方が、生成したＡＤＮ
の分離、回収が経済的であり、また、電解液の組滅を安
定に維持しやすく、高く安定したＡＤＮの収率が得られ
る。Therefore, in the industrialization of electrolytic trimerization of AN, as long as the oxidation of organic substances at the anode does not become large, the higher the oil phase ratio of the emulsion in the electrolyte, the better the produced ADN.
It is economical to separate and recover the electrolyte, and it is easy to maintain stable disintegration of the electrolyte, resulting in a high and stable yield of ADN.

また、従来の炭素鋼陽極では、陽極の腐食が大きく、溶
出した鉄イオンによる水素発生の増加があり、その水素
発生抑制のために繁雑な操作を必要とし、工業的な電解
においては、さらに腐食の少ない陽極が望まれる。さら
に、炭素鋼陽極は電極の取付は時や、電気を通じていな
い時に、その表面が錆びやすく、表面が錆びた陽極をそ
のまま電解反応に使用すると、その鉄錆が電解液に溶は
込んで、鉄イオン濃度を上昇させたり、表面に絶縁性付
着物が付着して電解電圧を上昇させる。したがって、電
解反応の前に表面の鉄錆を除去する必要があり、工業的
な実施においては、陽極表面が錆びに（いことも極めて
重要である。In addition, with conventional carbon steel anodes, the anode is severely corroded and hydrogen generation increases due to eluted iron ions, requiring complicated operations to suppress hydrogen generation. An anode with less is desired. Furthermore, the surface of carbon steel anodes tends to rust when the electrode is installed or when electricity is not being applied. If an anode with a rusted surface is used as is for an electrolytic reaction, the iron rust will dissolve into the electrolyte, causing the iron to rust. The ion concentration increases or insulating deposits adhere to the surface, increasing the electrolytic voltage. Therefore, it is necessary to remove iron rust on the surface before the electrolytic reaction, and in industrial implementation, it is extremely important that the anode surface is free from rust.

（問題点を解決するための手段） 本発明者らは、単一室電解槽によるＡＮの電解三量化の
工業化におけるこれらの問題点を解決するために、鋭意
研究を重ねた結果、アルカリ金属塩と第４級アンモニウ
ム塩からなる電導性支持塩とＡＮを含む電解液では、陽
極としてニッケル鋼を用いた場合、他の鉄、炭素鋼、鉛
等の陽極より陽極の腐食が少なく、かつ酸素過電圧が低
くて、電解液中の有機物の酸化が少ないことを見出した
。(Means for Solving the Problems) In order to solve these problems in the industrialization of electrolytic trimerization of AN using a single-chamber electrolyzer, the present inventors have conducted intensive research and found that alkali metal salts In an electrolytic solution containing AN and a conductive supporting salt consisting of a quaternary ammonium salt, when nickel steel is used as the anode, corrosion of the anode is less than that of other iron, carbon steel, lead, etc. anodes, and oxygen overvoltage is low. It was found that the oxidation of organic matter in the electrolyte was low.

このニッケル鋼陽極の使用により、電解液中の有機物濃
度が高くても、すなわち、電解液エマルジョンの油相比
率が３０％という高い範囲でも、有機物の酸化はほとん
ど起こらず、高い選択率でＡＤＮを得ることができた。By using this nickel steel anode, even when the concentration of organic matter in the electrolyte is high, that is, even when the oil phase ratio of the electrolyte emulsion is as high as 30%, oxidation of organic matter hardly occurs and ADN can be oxidized with high selectivity. I was able to get it.

この高い油相比率では、ＡＤＨの分離回収のためのデカ
ンタ−への電解液エマルジョンの供給量も少なくて済み
、また、電解液組成の乱れもなく安定したＡＤＮの収率
が得られた。そして、ニッケル鋼は炭素鋼より錆びに（
（、電解使用前に何ら処理することなく使用しても、電
解液中の鉄濃度の急上昇や、電圧上昇はなく、また、陽
極の腐食が少ない結果が得られ、本発明を完成するに至
った。With this high oil phase ratio, the amount of electrolyte emulsion supplied to the decanter for separating and recovering ADH was also small, and a stable ADN yield was obtained without disturbance of the electrolyte composition. And nickel steel is more susceptible to rust than carbon steel (
(Even if the electrolytic solution is used without any treatment before use, there is no sudden increase in the iron concentration in the electrolytic solution, no voltage increase, and little corrosion of the anode is obtained, which led to the completion of the present invention. Ta.

すなわち、本発明は、アルカリ金属塩と第４級アンモニ
ウム塩からなる電導性支持塩とＡＮを含む電解液エマル
ジョ／を、単一室電解槽で電解製造するに当り、陽極に
ニッケル鋼を用い、かつ電解液エマルジョンの油相の比
率が６〜３０重量％であることを特徴とするＡＤＮの製
造方法を提供するものである。That is, the present invention uses nickel steel for the anode when electrolytically producing an electrolyte emulsion containing AN and a conductive supporting salt consisting of an alkali metal salt and a quaternary ammonium salt in a single chamber electrolytic cell. The present invention also provides a method for producing ADN, characterized in that the proportion of the oil phase in the electrolyte emulsion is 6 to 30% by weight.

本発明に用いる単一室電解槽とは、陰極と陽極の間に隔
膜の存在しない電解槽のことである。The single-chamber electrolytic cell used in the present invention is an electrolytic cell in which there is no diaphragm between the cathode and the anode.

本発明においては、電導性支持塩としてアルカリ金属塩
と第４級アンモニウム塩の混合塩が用いられる。アルカ
リ金属塩単独の場合は、ＡＤＮの収率が低く、水素の発
生が多い、また、第４級アンモニウム塩単独の場合は電
解電圧が高い。したがって、収率、電圧、水素発生など
の点から、本発明においては、アルカリ金属塩と第４級
アンモニウム塩の混合塩が用いられる。In the present invention, a mixed salt of an alkali metal salt and a quaternary ammonium salt is used as the conductive supporting salt. When an alkali metal salt is used alone, the yield of ADN is low and a large amount of hydrogen is generated, and when a quaternary ammonium salt is used alone, the electrolytic voltage is high. Therefore, from the viewpoint of yield, voltage, hydrogen generation, etc., a mixed salt of an alkali metal salt and a quaternary ammonium salt is used in the present invention.

このアルカリ金属塩のカチオンとしては、例えば、リチ
ウム、ナトリウム、カリウム、ルビジウムなどが挙げら
れ、これらの中で、ナトリウムまたはカリウムが経済的
に得られやすい点で好ましい。これらのカチオンは、電
解液中に単独に含まれていても、また、２種以上混合し
て含まれていてもよい。これらアルカリ金属塩の濃度は
、その溶解度の範囲で任意に選ぶことができるが、溶液
の電導性を上昇させる目的から、電解液の水相に０．１
重量％以上、好ましくは１重量％以上である。Examples of the cation of this alkali metal salt include lithium, sodium, potassium, rubidium, etc. Among these, sodium or potassium is preferred because it is easily obtained economically. These cations may be contained singly in the electrolytic solution, or may be contained in a mixture of two or more types. The concentration of these alkali metal salts can be arbitrarily selected within the range of their solubility, but for the purpose of increasing the conductivity of the solution, 0.1
It is at least 1% by weight, preferably at least 1% by weight.

第４級アンモニウム塩のカチオンとしては、−で表され
る第４級アンモニウムが挙げられる。この一般式（Ｉ）
におけるＲ　ｌ＋　Ｒｚ、　Ｒ、ｌとしては、炭素数１
〜５のアルキル基、Ｒ４としては炭素数１〜８のアルキ
ル基が好ましく、このような第４級アンモニウムとして
、例えば、テトラエチル、テトラプロピル、テトラブチ
ル、エチルトリプロピル、エチルトリブチル、トリメチ
ルオクチルなどのアンモニウムが使用できる。ＡＤＮの
収率および油相への溶解度とその油相からの回収の容易
さから、最も好ましいものは、エチルトリプロピル、エ
チルトリブチルである。Examples of the cation of the quaternary ammonium salt include quaternary ammonium represented by -. This general formula (I)
R l+ Rz, R, l have a carbon number of 1
-5 alkyl group, R4 is preferably an alkyl group having 1 to 8 carbon atoms, and examples of such quaternary ammonium include ammoniums such as tetraethyl, tetrapropyl, tetrabutyl, ethyltripropyl, ethyltributyl, and trimethyloctyl. can be used. Ethyltripropyl and ethyltributyl are most preferred in terms of ADN yield, solubility in the oil phase, and ease of recovery from the oil phase.

第４級アンモニウム塩の濃度は、ＡＤＮ収率の向上、水
素発生の抑制の点から、水相基準の濃度で０．１〜２０
重量％、好ましくは０．５〜５重量％である。濃度が高
過ぎると、陽極で酸化分解を起こす。The concentration of the quaternary ammonium salt is 0.1 to 20% based on the aqueous phase, from the viewpoint of improving ADN yield and suppressing hydrogen generation.
% by weight, preferably 0.5-5% by weight. If the concentration is too high, oxidative decomposition will occur at the anode.

前記電導性支持塩として用いるアルカリ金属塩および第
４級アンモニウム塩のアニオンとしては、例えば、リン
酸、硫酸、ホウ酸、炭酸などの無機酸または多価酸の残
基が使用できる。これらのアニオンは、電解液中に単独
に含まれていてもよく、２種以上混合して含まれていて
もよいが、好ましくはリン酸イオンと無機酸または多価
酸のイオンが共に含まれていることであり、最も好まし
くはリン酸イオンとホウ酸イオンが共に含まれているこ
とである。ｐ−トルエンスルホン酸やエチル硫酸などの
有機残基を、アニオンとして併用することもできる。As the anion of the alkali metal salt and quaternary ammonium salt used as the conductive supporting salt, for example, residues of inorganic acids or polyhydric acids such as phosphoric acid, sulfuric acid, boric acid, and carbonic acid can be used. These anions may be contained singly or in a mixture of two or more types in the electrolyte, but preferably phosphate ions and inorganic acid or polyhydric acid ions are contained together. Most preferably, both phosphate ions and borate ions are contained. Organic residues such as p-toluenesulfonic acid and ethyl sulfate can also be used together as anions.

本発明は、陽極としてニッケル鋼を使用するが、ニッケ
ル鋼とは鉄とニッケルを主成分とする合金鋼で、例えば
、日本工業規格（Ｊ　Ｉ　Ｓ）　Ｇ　３１２７低温圧力
容器用ニツケル鋼鋼板に規定されたものが使用できるが
、この規定以外のニッケル含量のニッケル鋼も使用でき
る。すなわち、鉄およびニッケル以外の他の金属成分が
実質的に含まれない二・７ケル鋼が使用できる。ニッケ
ル含有率が高いほど酸素過電圧は低くなるが、半面、水
素の発生量が増加する。一方、ニッケル含有率が低過ぎ
ると、酸素過電圧を下げる効果はなくなり、陽極として
の腐食も大きくなるー。ニッケル鋼として、ニッケル１
〜１５重世％のものが好ましく、最も好ましいものはニ
ッケル３〜９重世％のものである。In the present invention, nickel steel is used as the anode, and nickel steel is an alloy steel whose main components are iron and nickel. Nickel steels with nickel contents other than those specified can also be used. That is, 2.7 Kel steel that does not substantially contain metal components other than iron and nickel can be used. The higher the nickel content, the lower the oxygen overvoltage, but on the other hand, the amount of hydrogen generated increases. On the other hand, if the nickel content is too low, there will be no effect of lowering the oxygen overvoltage, and corrosion as an anode will increase. As nickel steel, nickel 1
Preferred are those containing 15% to 15% nickel, and most preferred are 3 to 9% nickel.

本発明における電解液エマルジョンの油相の比率とは、
水相と油相からなるエマルジョン全体に対する油相の重
量比率である。油相は、ＡＮ、ＡＤＮ、副生成物、溶解
骨の水および溶解骨の第４級アンモニウム塩からなり、
水相は、水、アルカリ金属塩、第４級アンモニウム塩お
よび溶解骨のＡＮやＡＤＮを含む。油相の比率が低過ぎ
ると、前述の生成したＡＤＮの分離、回収が難しく、電
解液組成の安定維持が困難で、ＡＤＮ収率の変動を引き
起こしやすい。また、油相の比率が３０重量％より高い
と、ＡＮやＡＤＮなどの有機物が陽極酸化を受ける量が
増大する。したがって、エマルジョンの油相の比率は６
〜３０重量％の範囲が好ましく、さらに好ましくは１０
〜３０重量％、最も好ましくは１５〜３０重量％である
。The ratio of the oil phase of the electrolyte emulsion in the present invention is:
It is the weight ratio of the oil phase to the entire emulsion consisting of the water phase and the oil phase. The oil phase consists of AN, ADN, by-products, dissolved bone water and dissolved bone quaternary ammonium salts,
The aqueous phase contains water, alkali metal salts, quaternary ammonium salts, and dissolved bone AN and ADN. If the ratio of the oil phase is too low, it will be difficult to separate and recover the generated ADN as described above, it will be difficult to maintain a stable electrolyte composition, and the ADN yield will likely fluctuate. Moreover, when the ratio of the oil phase is higher than 30% by weight, the amount of organic substances such as AN and ADN that undergoes anodic oxidation increases. Therefore, the ratio of oil phase in the emulsion is 6
The range is preferably 30% by weight, more preferably 10% by weight.
~30% by weight, most preferably 15-30% by weight.

エマルジョンの油相中のＡＮ？ａ度は、好ましくは１０
〜４５重量％、さらに好ましくは１５〜３５重世％であ
る。ＡＮ濃度が低過ぎると、水素の発生が激しくなり、
逆に高過ぎると、ＡＮのポリマーなどの副生成物が増加
する。AN in the oil phase of the emulsion? a degree is preferably 10
~45% by weight, more preferably 15-35% by weight. If the AN concentration is too low, hydrogen generation will be intense,
On the other hand, if it is too high, by-products such as AN polymer will increase.

本発明における陰極は、一般に水素過電圧の高い材質が
使用できる。このようなものとしては、例えば、鉛、亜
鉛、カドミウム、グラファイトなど、およびそれらを主
成分とする合金である。これらの中で鉛およびカドミウ
ムおよびそれらを主成分とする合金が好適で、さらに、
ＡＤＮ収率や公害上の取扱いの容易さから、鉛および鉛
を土成分とする合金が最適である。The cathode in the present invention can generally be made of a material with a high hydrogen overvoltage. Examples of such materials include lead, zinc, cadmium, graphite, etc., and alloys containing these as main components. Among these, lead and cadmium and alloys containing them as main components are preferred;
From the viewpoint of ADN yield and ease of handling in terms of pollution, lead and alloys containing lead as a soil component are optimal.

本発明における電解液のｐ　Ｈは５以上が望ましく、好
ましくは６以上、さらに好ましくは７以上であるが、ｐ
Ｈ１０以上ではＡＮの副生成物が増大するので好ましく
ない。ｐＨ５以下では水素の発生が増大するので好まし
くない。The pH of the electrolytic solution in the present invention is desirably 5 or more, preferably 6 or more, more preferably 7 or more, but
If it is H10 or higher, the amount of AN by-products increases, which is not preferable. A pH of 5 or lower is not preferable because hydrogen generation increases.

電解時の電解槽内の電解液温度は、アルカリ金属塩の析
出点以上であればよいが、通常２０〜７５℃、好ましく
は３０〜７０℃、さらに好ましくは４５〜６５℃の範囲
である。The temperature of the electrolytic solution in the electrolytic cell during electrolysis may be at least the precipitation point of the alkali metal salt, but is usually in the range of 20 to 75°C, preferably 30 to 70°C, and more preferably 45 to 65°C.

電解時における電流密度は、陰極表面１　ｄｎ＋”当り
、通常０．０５〜７ＱＡ、好ましくは１〜５０Ａ、さら
に好ましくは５〜４０Ａの範囲である。The current density during electrolysis is usually in the range of 0.05 to 7 QA, preferably 1 to 50 A, and more preferably 5 to 40 A per 1 dn+'' of the cathode surface.

本発明において、電解槽における陰極と陽極の間隔は、
通常０．１〜５１の距離、好ましくは１〜３ｍｍの範囲
である。また、この電槽の電極間を電解液が通常０．１
〜４ｍ／秒、好ましくは０．５〜２．５ｍ／秒の速度で
通過する。In the present invention, the distance between the cathode and the anode in the electrolytic cell is
The distance is usually between 0.1 and 51 mm, preferably between 1 and 3 mm. In addition, the electrolyte between the electrodes of this container is usually 0.1
Passing at a speed of ~4 m/sec, preferably 0.5-2.5 m/sec.

（発明の効果） 本発明のＡＮの電解二型化法は、炭素鋼や鉛などを陽極
とし、エマルジョンを電解液とした方法に比べ、以下の
利点を有している。(Effects of the Invention) The method for electrolytically dimorphing AN of the present invention has the following advantages over methods using carbon steel, lead, or the like as an anode and emulsion as an electrolyte.

（１）　Ａ　Ｄ　Ｎの分離、回収が極めて容易に経済的
にできる。(1) ADN can be separated and recovered very easily and economically.

＋２）　Ａ　Ｄ　Ｎの収率が安定に高く維持できる。+2) The yield of ADN can be stably maintained at a high level.

（３）電解電圧が低（、長時間にわたって安定に維持で
きる。(3) Electrolysis voltage is low (and can be maintained stably for a long time).

（４）陽極の消耗が少なく、寿命が長い。(4) The anode wears out less and has a longer lifespan.

（５）炭素鋼陽極に比ベニッケル鋼陽極は錆びにくいた
め、非通電時の陽極の取扱いが掻めて容易である。(5) Compared to carbon steel anodes, nickel steel anodes are less likely to rust, making the anodes easier to handle when not energized.

（実施例） 次に、実施例によって本発明をさら詳細に説明する。(Example) Next, the present invention will be explained in more detail with reference to Examples.

実施例１ 単一室電解槽は１（ＪＸ９０Ｃ１ｌ＋の通電面を有する
鉛合金を陰極とし、同じ通電面を有するニッケル鋼（９
重量％Ｎｉ含有）を陽極として使用し、陰極と陽極の間
にスペーサーを置き、２ｍｍの間隔に保った。電解液は
２０重量％の油相と８０重量％の水相でエマルジョンを
なしており、水相の組成は、ＡＮ約２ＭＭ％、（ＥｔＢ
ｕＪ）　ＺＨＰＯ４約２ｆｉ量％、ＫｚｌｌＰＯ＜約１
０重量％、Ｋ２Ｂ４０？約３重量％および若干のＡＤＮ
１プロピオニトリル、１，３．５−　）リシアノヘキサ
ンを含んだ水溶液であり、リン酸でｐＨ７，８に調整し
た。油相は該水溶液と溶解平衡をなしており、その組成
は、ＡＮ約２８重量％、ＡＤＮ約５０重量％、プロピオ
ニトリルとＬ３，５−１〜リシアノヘキサン合わせて約
５重量％、　水約１２重量％、（ＥｔＢｕＪ）　、ＨＰ
Ｏ４約５重量％である。Example 1 A single-chamber electrolyzer uses a lead alloy (1) (JX90C1l+) with a conductive surface as the cathode, and a nickel steel (9) with the same conductive surface as the cathode.
wt % Ni) was used as the anode, and a spacer was placed between the cathode and the anode to maintain a distance of 2 mm. The electrolytic solution forms an emulsion with 20% by weight oil phase and 80% by weight water phase, and the composition of the water phase is approximately 2MM% AN, (EtB
uJ) ZHPO4 approx. 2fi amount%, KzllPO < approx. 1
0% by weight, K2B40? Approximately 3% by weight and some ADN
This is an aqueous solution containing 1-propionitrile, 1,3.5-) lycyanohexane, and the pH was adjusted to 7.8 with phosphoric acid. The oil phase is in solubility equilibrium with the aqueous solution, and its composition is approximately 28% by weight of AN, approximately 50% by weight of ADN, approximately 5% by weight of propionitrile and L3,5-1 to lycyanohexane, and water. Approximately 12% by weight, (EtBuJ), HP
The O4 content is about 5% by weight.

このエマルジョンを電解液タンクから通電面で線速１．
５ｍ／秒になるように単一室電解槽に供給循環し、電流
密度２０Ａ／ｄｍ”　、５５℃で電解を行った。通電と
同時に電解液タンクから電解液を連続的に一部抜き出し
、デカンタ−に送り、油相と水相に分離した。生成した
ＡＤＮおよび副生成物を、この油相としてデンカターよ
り抜き出した。水相はキレート樹脂を詰めた樹脂塔に通
し、溶出した重金属イオンを吸着Ｗ去し、電解液タンク
に連続的に戻した。上記電解液組成を保つように、ＡＮ
、水を連続的に添加し、油相に溶解して抜き出された（
ＥｔＢｕ：＋Ｎ）　ＺｌｌＰＯ４を随時添加した。This emulsion is transferred from the electrolyte tank to a current-carrying surface at a linear speed of 1.
The electrolyte was supplied and circulated to a single chamber electrolyzer at a rate of 5 m/sec, and electrolysis was carried out at a current density of 20 A/dm at 55°C. At the same time as electricity was applied, a portion of the electrolyte was continuously drawn out from the electrolyte tank and placed in a decanter. - and separated into an oil phase and an aqueous phase. The produced ADN and by-products were extracted from the Denkater as this oil phase. The aqueous phase was passed through a resin tower packed with chelate resin to adsorb the eluted heavy metal ions. W was removed and the electrolyte was continuously returned to the electrolyte tank.
, water was added continuously, dissolved in the oil phase and extracted (
EtBu: +N) ZllPO4 was added at any time.

このようにして２８３時間電解を行った結果、初期電圧
は３．７ｖで安定に推移し、発生ガスに含まれる水素は
、電解終了時で０．０５容量％であり、陽極の消耗速度
は０．１８ｍｇ／　Ａ　Ｈ１消費ＡＮに対するＡＤＮ収
率は９１．８％、電流効率は９０．７％であった。As a result of performing electrolysis for 283 hours in this way, the initial voltage remained stable at 3.7V, the hydrogen contained in the generated gas was 0.05% by volume at the end of electrolysis, and the consumption rate of the anode was 0. The ADN yield for .18 mg/A H1 consumed AN was 91.8%, and the current efficiency was 90.7%.

デカンタ−への電解液の供給量は２２ｃｃ／　Ａ　Ｈで
、生成したＡＤＮを分離、回収でき、電解液の組成を一
定に維持できた。The amount of electrolyte solution supplied to the decanter was 22 cc/AH, and the generated ADN could be separated and recovered, and the composition of the electrolyte solution could be maintained constant.

参考例１ 陽極を炭素鋼とした以外、実施例１と全く同様に電解を
行った。２７０時間の電解を行い、初期電圧４．ＯＶで
安定に推移し、水素は０．１９容量％であった。陽極の
消耗速度は０．２５ｍｇ／　Ａ　Ｈ、Ａ　Ｄ　Ｎ収率は
８７．８％、電流効率は８７．１％、デカンタ−への供
給量は２４ｃｃ／　Ａ　Ｈであった。Reference Example 1 Electrolysis was carried out in exactly the same manner as in Example 1, except that carbon steel was used as the anode. After 270 hours of electrolysis, the initial voltage was 4. It remained stable at OV, and the hydrogen content was 0.19% by volume. The consumption rate of the anode was 0.25 mg/AH, the ADN yield was 87.8%, the current efficiency was 87.1%, and the amount supplied to the decanter was 24 cc/AH.

参考例２ 陽極を鉛とした以外は、実施例１と全く同様に電解を行
った。初期電圧は４．８■であったが、２０時間後には
６．７ｖまで上昇した。陽極表面には高分子状の付着物
が付着していた。Reference Example 2 Electrolysis was carried out in the same manner as in Example 1, except that lead was used as the anode. The initial voltage was 4.8V, but it increased to 6.7V after 20 hours. Polymer-like deposits were found on the anode surface.

参考例３ 電解液のエマルジョンの油相を０．０５重量％とじて、
実施例１と同じように２９３時間電解した。電圧は３．
７Ｖで安定に推移し、水素は０．５１容量％であった。Reference Example 3 The oil phase of the electrolyte emulsion was 0.05% by weight,
Electrolysis was carried out in the same manner as in Example 1 for 293 hours. The voltage is 3.
The voltage remained stable at 7V, and the hydrogen content was 0.51% by volume.

陽極の消耗速度は０．１９ｍｇ／　Ａ　Ｈ、Ａ　Ｄ　Ｎ
収率は８７．４％、電流効率は８７．３％で、デカンタ
−への供給量は９３ｃｃ／　Ａ　Ｈ必要であった。The consumption rate of the anode is 0.19 mg/AH, AD N
The yield was 87.4%, the current efficiency was 87.3%, and the amount supplied to the decanter was 93 cc/AH.

実施例２ 実施例１と同じ電解槽を用い、電解液のエマルジョンの
油相を１０重量％とした以外、実施例１と同じように３
１０時間の電解を行った。初期電圧３．７Ｖで安定に推
移し、発生水素は０．０６容量％であった。陽極の消耗
速度は０．１７ｍｇ／　Ａ　Ｈ，Ａ　Ｄ　Ｎ収率は９１
．３％、電流効率は９０．８％で、デカンタ−への供給
量は４５ｃｃ／　Ａ　Ｈで、生成ＡＤＨが分離、回収で
きた。Example 2 The same electrolytic cell as in Example 1 was used, and 3.
Electrolysis was performed for 10 hours. The initial voltage remained stable at 3.7 V, and the amount of hydrogen generated was 0.06% by volume. The consumption rate of the anode is 0.17 mg/AH, ADN yield is 91
．． 3%, the current efficiency was 90.8%, the amount supplied to the decanter was 45 cc/AH, and the produced ADH could be separated and recovered.

実施例３ 実施例１と同じ電解槽を用い、電導性支持塩の第４級ア
ンモニウム塩にエチルトリブチルアンモニウムリン酸塩
を使用し、油相３０重量％、水相７０重量％のエマルジ
ョンの電解液を用いた。水相の組成は、ＡＮ約２重量％
、（ＨｔＰｒＪ）　ｚＨＰＯ４約３重量％、Ｍ２）ＩＰ
Ｏ，約ｉｏ重量％、ＫｚＢａＯ□約２．５重量％、そし
て、若干のＡＤＮおよび副生成物を含んだ水溶液であり
、リン酸でｐＨ７，５に調整した。油相の組成は、ＡＮ
約３０重量％、ＡＤＮ約５２重量％、プロピオニトリル
と１．３．５−）リシアノヘキサン合わせて約５重量％
、水１１重量％、（ＥｔＢｕ：＋Ｎ）　ＺＩＩＰＯ４約
２重量％である。Example 3 Using the same electrolytic cell as in Example 1, using ethyltributylammonium phosphate as the quaternary ammonium salt of the conductive supporting salt, an electrolyte of an emulsion containing 30% by weight of the oil phase and 70% by weight of the aqueous phase was prepared. was used. The composition of the aqueous phase is approximately 2% by weight of AN.
, (HtPrJ) zHPO4 approx. 3% by weight, M2) IP
It was an aqueous solution containing about io weight % of O, about 2.5 weight % of KzBaO□, and some ADN and by-products, and the pH was adjusted to 7.5 with phosphoric acid. The composition of the oil phase is AN
Approximately 30% by weight, approximately 52% by weight of ADN, approximately 5% by weight of propionitrile and 1.3.5-) lycyanohexane.
, 11% by weight of water, and about 2% by weight of (EtBu:+N)ZIIPO4.

電解槽での線速度を２ｍ／秒とし、実施例１と同じよう
に油相を分離し、生成したＡＤＮを抜き出した。The linear velocity in the electrolytic cell was set to 2 m/sec, the oil phase was separated in the same manner as in Example 1, and the produced ADN was extracted.

２９４時間の電解を行い、初期電圧は３．８ｖで安定に
推移し、発生ガスに含まれる水素は電解終了時０．１４
容量％であった。陽極の消耗速度は０．１９ｍｇ／ＡＨ
，ＡＤＮ収率は９０．８％、電流効率は８９．３％で、
デカンタ−への電解液の供給量は１５ｃｃ／　Ａ　Ｈで
、生成ＡＤＮの分離、回収ができた。After 294 hours of electrolysis, the initial voltage remained stable at 3.8V, and the hydrogen contained in the generated gas was 0.14V at the end of electrolysis.
It was % by volume. The consumption rate of the anode is 0.19mg/AH
, ADN yield was 90.8%, current efficiency was 89.3%,
The amount of electrolyte supplied to the decanter was 15 cc/AH, and the produced ADN could be separated and recovered.

実施例４ 陽極にニッケル鋼（３重量％Ｎｉ含有）を用いた以外は
、実施例１と同じ条件で電解を行った。Example 4 Electrolysis was carried out under the same conditions as in Example 1, except that nickel steel (containing 3% by weight of Ni) was used for the anode.

２８７時間の電解で、電圧は３．８Ｖで安定に推移した
。発生水素は０．０３容量％、陽極の消耗速度は０．２
１ｍｇ／　Ａ　Ｈ、Ａ　Ｄ　Ｎ収率は９０．６％、電流
効率は８９．４％で、デカンタ−への供給量は２４ｃｃ
／　Ａ　Ｈであった。After 287 hours of electrolysis, the voltage remained stable at 3.8V. Generated hydrogen is 0.03% by volume, anode consumption rate is 0.2
The yield of 1mg/AH, ADN is 90.6%, the current efficiency is 89.4%, and the amount supplied to the decanter is 24cc.
/ AH.

実施例５ 陽極にニッケル鋼（１５重量％Ｎｉ含有）を用い、エマ
ルジョンの油相１５重量％、水相８５重量％以外は、実
施例１と同じように電解した。２７６時間の電解で、電
圧は３．６Ｖで安定に准移し、発生水素は０．５０容量
％、陽極消耗速度は０．１７ｍｇ／ＡＩ、ＡＤＮ収率は
９０．８％、電流効率８９．８％であった。デカンタ−
への供給量は、３６ｃｃ／　Ａ　Ｈ必要であった。Example 5 Nickel steel (containing 15% by weight of Ni) was used for the anode, and electrolysis was carried out in the same manner as in Example 1, except for the oil phase of the emulsion of 15% by weight and the water phase of 85% by weight. After 276 hours of electrolysis, the voltage was stable at 3.6V, the generated hydrogen was 0.50% by volume, the anode consumption rate was 0.17mg/AI, the ADN yield was 90.8%, and the current efficiency was 89.8. %Met. Decanter
36cc/AH was required.

実施例６ 陽極にニッケル鋼（５重量％Ｎｉ含有）を用い、電導性
支持塩のアルカリ金属塩をＫｄｌＰＯｎからＮａ２１１
Ｐ０４に代えて、実施例１と同じような条件で３１２時
間電解した。電圧は３．７Ｖで安定に推移し、発生水素
は０．０５容量％、陽極消耗速度は０．１８ｍｇ／ＡＨ
，ＡＤＮ収率は９１．６％、電流効率は９０．４％、デ
カンタ−への供給量は３５ｃｃ／　Ａ　Ｈであった。Example 6 Nickel steel (containing 5 wt% Ni) was used for the anode, and the alkali metal salt of the conductive supporting salt was changed from KdlPOn to Na211.
Electrolysis was performed for 312 hours under the same conditions as in Example 1 in place of P04. The voltage remains stable at 3.7V, the hydrogen generated is 0.05% by volume, and the anode consumption rate is 0.18mg/AH.
The ADN yield was 91.6%, the current efficiency was 90.4%, and the amount supplied to the decanter was 35 cc/AH.

Claims (5)

【特許請求の範囲】[Claims] （１）陽極にニッケル鋼を用い、アルカリ金属塩と第４
級アンモニウム塩からなる電導性支持塩とアクリロニト
リルを含むエマルジョンを電解液とし、かつエマルジョ
ンの油相の比率が６〜３０重量％で、単一室電解槽で電
解することを特徴とするアクリロニトリルの電解二量化
法。(1) Using nickel steel for the anode, alkali metal salt and
Electrolysis of acrylonitrile, characterized in that the electrolyte is an emulsion containing a conductive supporting salt consisting of a grade ammonium salt and acrylonitrile, the ratio of the oil phase of the emulsion is 6 to 30% by weight, and the electrolysis is carried out in a single chamber electrolytic cell. Dimerization method. （２）ニッケル鋼のニッケル含量が１〜１５重量％であ
る特許請求の範囲第１項記載の方法。(2) The method according to claim 1, wherein the nickel content of the nickel steel is 1 to 15% by weight. （３）アルカリ金属塩のカチオンがナトリウムあるいは
カリウムである特許請求の範囲第１項記載の方法。(3) The method according to claim 1, wherein the cation of the alkali metal salt is sodium or potassium. （４）エマルジョンの油相の比率が１０〜３０重量％で
ある特許請求の範囲第１項記載の方法。(4) The method according to claim 1, wherein the proportion of the oil phase in the emulsion is 10 to 30% by weight. （５）エマルジョンの油相の比率が１５〜３０重量％で
ある特許請求の範囲第１項記載の方法。(5) The method according to claim 1, wherein the proportion of the oil phase in the emulsion is 15 to 30% by weight.