JPH10110284A - Electrolytic fluorination method - Google Patents
Electrolytic fluorination methodInfo
- Publication number
- JPH10110284A JPH10110284A JP8266307A JP26630796A JPH10110284A JP H10110284 A JPH10110284 A JP H10110284A JP 8266307 A JP8266307 A JP 8266307A JP 26630796 A JP26630796 A JP 26630796A JP H10110284 A JPH10110284 A JP H10110284A
- Authority
- JP
- Japan
- Prior art keywords
- hydrogen fluoride
- electrolytic cell
- electrolytic
- liquid
- fluorinated
- 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.)
- Pending
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、被電解液中の陽極およ
び陰極の間で電気化学的に有機化合物をフッ素化する電
解フッ素化方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic fluorination method for electrochemically fluorinating an organic compound between an anode and a cathode in an electrolyte.
【０００２】[0002]
【従来の技術】有機化合物を電気化学的にフッ素化する
電解フッ素化法はよく知られている。例えば、特開昭４
７−１８７７５号公報には、有機化合物を含む被電解液
を循環させながら有機化合物のフッ素化を行うことが示
されている。さらに同公報には電解槽の排ガスを凝縮器
に送り、水素や有機化合物の分解ガスなどの排ガスに同
伴するフッ化水素やガス状のフッ素化生成物を凝縮さ
せ、得られた凝縮液を循環させるための貯槽に戻すこと
が示されている。2. Description of the Related Art An electrolytic fluorination method for electrochemically fluorinating an organic compound is well known. For example, JP
JP-A-7-18775 discloses that an organic compound is fluorinated while circulating an electrolytic solution containing the organic compound. In addition, the publication discloses that the exhaust gas from the electrolytic cell is sent to a condenser to condense hydrogen fluoride and gaseous fluorinated products accompanying the exhaust gas, such as hydrogen and decomposition gases of organic compounds, and circulate the obtained condensate. It is shown to be returned to a storage tank for replenishment.
【０００３】[0003]
【発明が解決しようとする課題】電解フッ素化を工業的
に実施する場合、電極部分で発生する熱を電解槽外部に
設けたクーラーで除去する、あるいは、電解の安定性を
増す等の目的で、被電解液を電解槽外に一旦取り出して
冷却し、それを再び電解槽内に供給して被電解液の循環
を行うことが好ましい。この場合、電解槽において生成
したフッ素化生成物が電解槽から排出され、循環により
再び電解槽に供給されると、フッ素化生成物が電解を受
けて分解し、フッ素化生成物の収量の低下や電解電圧の
上昇等の不都合が生じる。このため、被電解液の循環操
作を行う場合には、被電解液からフッ素化生成物を効率
的に分離する必要があり、内部構造が複雑で大型の付帯
設備が必要であった。従って、前記特開昭４７−１８７
７５号公報に記載される方法でも、被電解液を循環する
ための貯槽で、生成したフッ素化生成物が分離されてお
り、そのため前記排ガスに同伴して排出されたガス状の
フッ素化生成物も該循環槽で系外へ分離されている。When electrolytic fluorination is carried out industrially, the heat generated at the electrode portion is removed by a cooler provided outside the electrolytic cell, or for the purpose of increasing the stability of electrolysis. It is preferable that the electrolytic solution is once taken out of the electrolytic bath, cooled, and then supplied again into the electrolytic bath to circulate the electrolytic solution. In this case, when the fluorinated product generated in the electrolytic cell is discharged from the electrolytic cell and supplied to the electrolytic cell again by circulation, the fluorinated product undergoes electrolysis and is decomposed, thereby lowering the yield of the fluorinated product. And inconvenience such as an increase in electrolytic voltage. For this reason, when circulating the electrolytic solution, it is necessary to efficiently separate the fluorinated product from the electrolytic solution, and the internal structure is complicated and large-scale auxiliary equipment is required. Accordingly, Japanese Patent Application Laid-Open No.
Also in the method described in Japanese Patent Publication No. 75, the generated fluorinated product is separated in a storage tank for circulating the liquid to be electrolyzed, so that the gaseous fluorinated product discharged together with the exhaust gas Is also separated out of the system by the circulation tank.
【０００４】しかしながら、これらの分離設備を設置し
ても、被電解液中においてフッ素化生成物を効率的に分
離することはお互いの比重差の小ささ等から容易ではな
く、結果としてフッ素化生成物は必ずしも満足し得る収
率で得られていなかった。However, even if these separation facilities are installed, it is not easy to efficiently separate the fluorinated products in the liquid to be electrolyzed due to the small difference in specific gravity between them. The product was not always obtained in a satisfactory yield.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、上記した
課題に鑑み、電解フッ素化における収率を向上させる方
法について鋭意検討を続けてきた。この結果、循環を伴
う電解フッ素化方法において、電解槽から排出されるガ
ス相を冷却して、ガス相中のフッ化水素とフッ素化生成
物を凝縮したのち分液して、フッ素化生成物の液相を被
電解液と混合させることなく分離して取り出し、フッ化
水素の液相を被電解液に戻すことで収率を向上させ得る
ことを見出し、本発明を完成させるに至った。Means for Solving the Problems In view of the above-mentioned problems, the present inventors have intensively studied a method for improving the yield in electrolytic fluorination. As a result, in the electrolytic fluorination method involving circulation, the gas phase discharged from the electrolytic cell is cooled, and the hydrogen fluoride and the fluorinated product in the gas phase are condensed and then separated to separate the fluorinated product. The liquid phase was separated and taken out without mixing with the liquid to be electrolyzed, and it was found that the yield could be improved by returning the liquid phase of hydrogen fluoride to the liquid to be electrolyzed, thereby completing the present invention.
【０００６】すなわち、本発明は、電解槽に存在する有
機化合物を含む被電解液の一部を抜き出し、これを再度
電解槽に循環させながら、該電解槽中で有機化合物の電
解フッ素化を行う方法において、電解槽から排出される
ガス相を冷却して該ガス相中のフッ化水素およびフッ素
化生成物を凝縮させ、次いで得られた凝縮液をフッ化水
素の液相とフッ素化生成物の液相とに分液し、フッ化水
素の液相を上記被電解液に混合することを特徴とする電
解フッ素化方法である。That is, according to the present invention, a part of a liquid to be electrolyzed containing an organic compound present in an electrolytic cell is extracted, and the organic compound is electrolytically fluorinated in the electrolytic cell while circulating the part again through the electrolytic cell. In the method, the gas phase discharged from the electrolytic cell is cooled to condense the hydrogen fluoride and the fluorinated product in the gas phase, and then the condensate obtained is mixed with the liquid phase of hydrogen fluoride and the fluorinated product. Wherein the liquid phase of hydrogen fluoride is mixed with the liquid to be electrolyzed.
【０００７】本発明において電解フッ素化は、有機化合
物をフッ化水素に溶解または分散させて行う公知の方法
により実施される。具体的には、陽極および陰極を備え
た電解槽に、フッ化水素と有機化合物とを供給し、陽極
および陰極間に通電することにより行われる。In the present invention, electrolytic fluorination is carried out by a known method in which an organic compound is dissolved or dispersed in hydrogen fluoride. Specifically, this is performed by supplying hydrogen fluoride and an organic compound to an electrolytic cell having an anode and a cathode, and supplying an electric current between the anode and the cathode.
【０００８】電解フッ素化に用いるフッ化水素は、市販
されている無水フッ化水素酸がそのまま、あるいは必要
に応じて微量含まれる水分を予め低電流密度での電解等
の公知の方法で除去したのちに用いられる。As the hydrogen fluoride used for electrolytic fluorination, commercially available anhydrous hydrofluoric acid is used as it is, or if necessary, a trace amount of water is removed by a known method such as electrolysis at a low current density. Used later.
【０００９】フッ素化の対象となる有機化合物として
は、炭素原子に直接結合した水素原子を有する有機化合
物、窒素原子に直接結合した水素原子を有する有機化合
物および炭素−炭素二重結合を有する有機化合物等が使
用できる。例えば、これまで電解フッ素化の対象として
知られている脂肪族炭化水素、芳香族炭化水素等の炭化
水素類；直鎖または環状の脂肪族第一アミン、第二アミ
ンまたは第三アミン、芳香族アミン等のアミン類；直鎖
または環状の脂肪族エーテル、芳香族エーテル、ポリエ
ーテル等のエーテル類；直鎖または環状の脂肪族アルコ
ール、芳香族アルコール等のアルコール類；フェノール
類；直鎖または環状の脂肪族カルボン酸、芳香族カルボ
ン酸等およびこれらから誘導されるカルボン酸クロリ
ド、カルボン酸フルオリド等のカルボン酸ハライド、あ
るいは酸無水物、エステル等のカルボン酸およびその誘
導体類；ケトン類；アルデヒド類；脂肪族スルホン酸、
芳香族スルホン酸およびこれらから誘導されるスルホン
酸クロリド、スルホン酸フルオリド等のスルホン酸ハラ
イド、あるいはエステルなどのスルホン酸およびその誘
導体類；チオール、チオエーテルなどの含イオウ化合物
などを挙げることができる。The organic compounds to be fluorinated include organic compounds having a hydrogen atom directly bonded to a carbon atom, organic compounds having a hydrogen atom directly bonded to a nitrogen atom, and organic compounds having a carbon-carbon double bond. Etc. can be used. For example, hydrocarbons such as aliphatic hydrocarbons and aromatic hydrocarbons which have hitherto been known as objects of electrolytic fluorination; linear or cyclic aliphatic primary amines, secondary amines or tertiary amines, aromatics Amines such as amines; linear or cyclic aliphatic ethers, aromatic ethers, ethers such as polyethers; linear or cyclic alcohols such as aliphatic alcohols and aromatic alcohols; phenols; linear or cyclic Carboxylic acids such as aliphatic carboxylic acids and aromatic carboxylic acids, and carboxylic acid chlorides and carboxylic acid fluorides derived therefrom; or carboxylic acids such as acid anhydrides and esters; and derivatives thereof; ketones; aldehydes An aliphatic sulfonic acid,
Examples thereof include aromatic sulfonic acids and sulfonic acid halides such as sulfonic acid chloride and sulfonic acid fluoride derived therefrom, and sulfonic acids and derivatives thereof such as esters; and sulfur-containing compounds such as thiol and thioether.
【００１０】これらのなかでも電解フッ素化で用いるフ
ッ化水素への溶解性を勘案すると、分子中に窒素原子、
酸素原子、硫黄原子のうちの少なくとも一つを有する有
機化合物が好ましい。もちろん、炭化水素類のようにフ
ッ化水素への溶解性が低いものも使用できる。上記した
有機化合物の水素原子が一部フッ素原子のようなハロゲ
ン原子で置換された有機化合物も、原料として用い得る
ことは言うまでもない。また、伝導度増加剤などとして
二硫化メチルなどの第三成分を被電解液に添加しても良
い。Among these, considering the solubility in hydrogen fluoride used in electrolytic fluorination, nitrogen atoms and
Organic compounds having at least one of an oxygen atom and a sulfur atom are preferred. Of course, those having low solubility in hydrogen fluoride such as hydrocarbons can also be used. Needless to say, an organic compound in which a hydrogen atom of the above organic compound is partially substituted with a halogen atom such as a fluorine atom can also be used as a raw material. Further, a third component such as methyl disulfide may be added to the liquid to be electrolyzed as a conductivity increasing agent or the like.
【００１１】上記した有機化合物のなかでも、本発明に
よる効果が顕著である化合物は、アンモニアおよび炭素
原子の数が１〜１２個の有機化合物、さらには炭素原子
の数が４〜９個の有機化合物である。Among the above-mentioned organic compounds, compounds having a remarkable effect according to the present invention include ammonia and organic compounds having 1 to 12 carbon atoms, and organic compounds having 4 to 9 carbon atoms. Compound.
【００１２】上記した有機化合物を例示すれば、トリエ
チルアミン、トリプロピルアミン、トリブチルアミン、
ジメチルエチルアミン、ジブチルプロピルアミン、Ｎ，
Ｎ，Ｎ，Ｎ−テトラメチルエチレンジアミン、Ｎ，Ｎ−
ジメチルアニリン、Ｎ，Ｎ−ジエチルアニリン、モルホ
リン、Ｎ−メチルモルホリン、Ｎ−エチルモルホリン、
Ｎ−プロピルモルホリン、Ｎ−ブチルモルホリン、２−
ブチルフラン、２−プロピルピラン、ジエチルエーテ
ル、ジブチルエーテル、テトラヒドロフラン、ブタンチ
オール、オクタンチオール、ブタン、ペンタン、ヘキサ
ン、ヘプタン、オクタン、ヘキセン、オクテン、ヘキシ
ン、オクチン、メタンスルホン酸ハライド、ヘキサンス
ルホン酸ハライド、オクタンスルホン酸ハライド、ブチ
リルカルボン酸ハライド、オクチルカルボン酸ハライ
ド、ブタンチオール、オクタンチオールなどを挙げるこ
とができる。Examples of the above organic compounds include triethylamine, tripropylamine, tributylamine,
Dimethylethylamine, dibutylpropylamine, N,
N, N, N-tetramethylethylenediamine, N, N-
Dimethylaniline, N, N-diethylaniline, morpholine, N-methylmorpholine, N-ethylmorpholine,
N-propyl morpholine, N-butyl morpholine, 2-
Butylfuran, 2-propylpyran, diethylether, dibutylether, tetrahydrofuran, butanethiol, octanethiol, butane, pentane, hexane, heptane, octane, hexene, octene, hexine, octin, methanesulfonic acid halide, hexanesulfonic acid halide, Octanesulfonic acid halide, butyrylcarboxylic acid halide, octylcarboxylic acid halide, butanethiol, octanethiol and the like can be mentioned.
【００１３】原料のフッ化水素と有機化合物の電解槽へ
の供給方法は、バッチ式および連続式のいずれの方法で
行っても良い。本発明に従えば長期間にわたって安定に
高収率で電解フッ素化を実施できるため、連続式で行う
ことが特に好ましい。The method of supplying the raw material hydrogen fluoride and the organic compound to the electrolytic cell may be any of a batch method and a continuous method. According to the present invention, the electrolytic fluorination can be stably performed at a high yield over a long period of time, and therefore, it is particularly preferable to perform the continuous process.
【００１４】電解槽は、ニッケルまたはその合金、鉄、
ステンレススチール、銅などのほか、フッ素樹脂も用い
ることができる。The electrolytic cell is made of nickel or its alloy, iron,
In addition to stainless steel, copper, etc., fluorine resin can also be used.
【００１５】陽極は、ニッケルまたはその合金を用いれ
ば良い。なかでも、純度９９％以上、特に純度９９．５
％以上のほぼ純粋なニッケルを用いることが好ましい。
陰極としては、ニッケルまたはその合金のほかに鉄、ス
テンレススチール、銅などを用いることができる。陽極
と陰極との極間距離は、０．５〜７ｍｍ、好ましくは
１．５〜５ｍｍとすればよい。The anode may be made of nickel or its alloy. Above all, a purity of 99% or more, especially a purity of 99.5
% Or more of substantially pure nickel is preferably used.
As the cathode, iron, stainless steel, copper, or the like can be used in addition to nickel or an alloy thereof. The distance between the anode and the cathode may be 0.5 to 7 mm, preferably 1.5 to 5 mm.
【００１６】本発明の特徴は、電解槽に存在する有機化
合物を含む被電解液の一部を抜き出し、これを再度電解
槽に循環させながら、該電解槽中で有機化合物の電解フ
ッ素化を行う方法において、電解槽から排出されるガス
相を冷却して、該ガス相中のフッ化水素およびフッ素化
生成物を凝縮させ、次いで得られた凝縮液をフッ化水素
の液相とフッ素化生成物の液相とに分液し、フッ素化生
成物の液相を被電解液と混合させることなく分離して取
り出し、フッ化水素の液相を上記被電解液に混合するこ
とである。A feature of the present invention is that a part of a liquid to be electrolyzed containing an organic compound present in an electrolytic cell is extracted, and the organic compound is electrolytically fluorinated in the electrolytic cell while being circulated again to the electrolytic cell. In the method, the gas phase discharged from the electrolytic cell is cooled to condense the hydrogen fluoride and fluorinated products in the gas phase, and then the condensate obtained is combined with the liquid phase of hydrogen fluoride and the fluorinated product. The liquid phase of the fluorinated product is separated and taken out without mixing with the liquid to be electrolyzed, and the liquid phase of hydrogen fluoride is mixed with the liquid to be electrolyzed.
【００１７】電解槽に存在する被電解液の抜き出し方法
は、ポンプを用いる、あるいは電解で発生する水素ガス
を用いたガスリフトを利用する等の公知の方法で行えば
良い。被電解液の抜き出しは、通常連続的に行うのが良
い。電解液の一部を抜き出し、これを再度電解槽に戻し
て循環を行うため、電解槽とは別の貯槽である循環槽を
用いても良いし、循環槽を用いず電解槽から直接被電解
液を抜き出し、再び電解槽に戻しても良い。被電解液の
循環により被電解液は電解槽内の陽陰極間をある線速度
で移動することになる。この場合の被電解液の陽陰極間
での線速度は１ｃｍ／秒以上、好ましくは３ｃｍ／秒以
上であることが、長期間にわたって安定に電解できるた
めに特に好ましく、上記の線速度を採用し得るように電
解槽からの抜き出し量を調整することが好ましい。電解
槽内での電極間内の循環の方向は、通常上向きで良い
が、下向きあるいはその他の向きであっても良い。The method for extracting the electrolytic solution present in the electrolytic cell may be performed by a known method such as using a pump or a gas lift using hydrogen gas generated by electrolysis. The extraction of the electrolytic solution is usually preferably performed continuously. A part of the electrolytic solution is withdrawn and returned to the electrolytic cell to circulate again.Therefore, a circulating tank, which is a separate storage tank from the electrolytic tank, may be used. The liquid may be withdrawn and returned to the electrolytic cell again. Due to the circulation of the electrolytic solution, the electrolytic solution moves between the positive and negative electrodes in the electrolytic cell at a certain linear velocity. In this case, the linear velocity between the positive electrode and the negative electrode of the liquid to be electrolyzed is preferably 1 cm / sec or more, and more preferably 3 cm / sec or more in order to stably perform electrolysis over a long period of time. It is preferable to adjust the amount of extraction from the electrolytic cell so as to obtain it. The direction of circulation between the electrodes in the electrolytic cell may be generally upward, but may be downward or another direction.
【００１８】本発明における電解フッ素化は、電解槽か
ら排出されるガス相を冷却して、該ガス相中のフッ化水
素とフッ素化生成物を凝縮したのち分液して、フッ素化
生成物の液相を分離して取り出し、フッ化水素の液相を
被電解液に戻すことで行われる。ガス相は、電解槽から
直接排出させても良いし、被電解液の循環ラインの任意
の箇所で排出させても良い。電解槽から排出されるガス
相の冷却方法は、ガス相を冷媒や水により冷却できる冷
却器に通じる等の公知の方法を用いれば良い。冷却器
は、直列あるいは並列に２基以上用いても良い。冷却す
る温度は、低いほど好ましいが、通常−８０℃〜１０℃
の範囲から選べば良い。In the electrolytic fluorination of the present invention, the gas phase discharged from the electrolytic cell is cooled, and the hydrogen fluoride and the fluorinated product in the gas phase are condensed and then separated to separate the fluorinated product. The liquid phase is separated and taken out, and the liquid phase of hydrogen fluoride is returned to the electrolytic solution. The gas phase may be directly discharged from the electrolytic cell, or may be discharged at an arbitrary position in a circulation line of the liquid to be electrolyzed. As a method for cooling the gas phase discharged from the electrolytic cell, a known method such as passing a gas phase to a cooler capable of cooling with a refrigerant or water may be used. Two or more coolers may be used in series or in parallel. The cooling temperature is preferably as low as possible, but it is usually −80 ° C. to 10 ° C.
You can choose from the range.
【００１９】電解槽から排出されるガス相を冷却するこ
とにより、ガス相中のフッ化水素とフッ素化生成物が凝
縮される。フッ素化生成物はフッ化水素にほとんど溶解
しないため、ここで、フッ素化生成物とフッ化水素とを
分液することにより、ガス相に同伴したフッ素化生成物
は極めて効率的に分離できる。なお、フッ化水素とフッ
素化生成物を凝縮した後の気相は、水素ガスや有機化合
物の分解ガスが主であり、これらは排ガスとして処理す
ればよい。By cooling the gas phase discharged from the electrolytic cell, hydrogen fluoride and fluorinated products in the gas phase are condensed. Since the fluorinated product hardly dissolves in hydrogen fluoride, the fluorinated product entrained in the gas phase can be separated very efficiently by separating the fluorinated product and hydrogen fluoride. The gas phase after the condensation of the hydrogen fluoride and the fluorinated product is mainly composed of hydrogen gas or a decomposition gas of an organic compound, and these may be treated as exhaust gas.
【００２０】凝縮液の分液方法は、デカンター等の分液
槽や液体サイクロン等の二層を分離しうる公知の方法を
用いれば良い。分液操作は、バッチ式および連続式のい
ずれの方法で行っても良い。分液したフッ化水素は、連
続式あるいはバッチ式でポンプやオーバーフロー形式で
送液し被電解液に混合すれば良い。その場合、被電解液
への混合箇所は、電解槽に対してが好適であるが、電解
槽から抜き出された後の循環ラインであっても、あるい
は循環槽が設けられている場合においては該循環槽に対
してであっても何ら問題はない。一方、分液されたフッ
素化生成物も連続式あるいはバッチ式でポンプやオーバ
ーフロー形式により系外に取り出せば良い。As a method for separating the condensed liquid, a known method capable of separating two layers such as a separating tank such as a decanter and a liquid cyclone may be used. The liquid separation operation may be performed by any of a batch method and a continuous method. The separated hydrogen fluoride may be fed by a pump or an overflow system in a continuous or batch system and mixed with the electrolyte. In that case, the mixing portion to the liquid to be electrolyzed is preferably for the electrolytic cell, but even in a circulation line after being extracted from the electrolytic cell, or in the case where the circulation tank is provided. There is no problem even for the circulation tank. On the other hand, the separated fluorinated product may be taken out of the system by a pump or an overflow system in a continuous or batch system.
【００２１】本発明に従えば長期間にわたって安定に電
解フッ素化を実施できるため、分液とフッ化水素の被電
解液への混合ならびにフッ素化生成物の取り出しを連続
式で行うことが特に好ましい。なかでも、凝縮液がショ
ートパスして送液され被電解液と混合されないように内
部に堰を設けたデカンターを利用することが、簡便で効
果的であり、特に好ましく用いられる。また、連続式の
場合、分液装置内においてフッ化水素ならびにフッ素化
生成物の滞在時間をそれぞれ１０分から３時間の範囲か
ら、さらに３０分から９０分の範囲から選ぶことが特に
好ましい。According to the present invention, electrolytic fluorination can be stably performed over a long period of time. Therefore, it is particularly preferable that the separation of the liquid and the mixture of hydrogen fluoride and the fluorinated product be carried out continuously. . Above all, it is simple and effective to use a decanter provided with a weir so that the condensed liquid is sent through a short path and is not mixed with the liquid to be electrolyzed, and is particularly preferably used. In the case of the continuous type, it is particularly preferable to select the residence time of hydrogen fluoride and the fluorinated product in the liquid separating apparatus from the range of 10 minutes to 3 hours, respectively, and more preferably from the range of 30 minutes to 90 minutes.
【００２２】本発明における電解条件は、公知の範囲か
ら選べばよいが、電解槽から排出されるガス相にフッ素
化生成物が積極的に含まれ得る条件が好ましい。すなわ
ち、電解温度はできるだけ高い方が好ましく、被電解液
の沸点より２０℃低い温度から被電解液の沸点までの温
度範囲から選ぶのが特に好ましい。また、電解の電流密
度は、単位電槽内での水素ガス量が多くなるためできる
だけ高い方が好ましく、３〜５０Ａ／ｄｍ2の範囲、特
に７〜２０Ａ／ｄｍ2の範囲から選ぶのが好ましい。電
解圧力は、常圧あるいは加圧下で実施しても良い。被電
解液中における有機化合物の濃度は１０〜４０重量％、
電解電圧は４〜９Ｖから選択すれば良い。また、被電解
液への窒素ガス等の不活性ガスの吹き込み等の操作を行
っても良い。本発明では、電解槽から排出されるガス相
にフッ素化生成物が積極的に含まれ得る電解条件を採用
することが好ましいが、該条件を採用できない場合、被
電解液に溶解するフッ素化生成物を該被電解液から分離
するための分離槽等を用いても良い。なお、こうした場
合においても、ガス相に同伴したフッ素化生成物につい
ては、本発明の方法を採用することにより、高収率で分
離することが可能であり効果的である。The electrolysis conditions in the present invention may be selected from known ranges, but are preferably conditions under which fluorinated products can be positively contained in the gas phase discharged from the electrolyzer. That is, it is preferable that the electrolysis temperature is as high as possible, and it is particularly preferable that the electrolysis temperature be selected from a temperature range from 20 ° C. lower than the boiling point of the liquid to be electrolyzed to the boiling point of the liquid to be electrolyzed. Also, the current density of electrolysis is as high as possible is preferable for the hydrogen gas amount increases in the unit battery container within the range of 3~50A / dm 2, in particular to choose from a range of 7~20A / dm 2 preferably . Electrolysis pressure may be carried out at normal pressure or under pressure. The concentration of the organic compound in the electrolyte is 10 to 40% by weight,
The electrolysis voltage may be selected from 4 to 9V. Further, an operation such as blowing an inert gas such as a nitrogen gas into the electrolytic solution may be performed. In the present invention, it is preferable to employ electrolysis conditions in which the fluorinated product can be positively contained in the gas phase discharged from the electrolytic cell. A separation tank or the like for separating a substance from the electrolytic solution may be used. Even in such a case, the fluorinated product entrained in the gas phase can be separated in high yield by employing the method of the present invention, which is effective.
【００２３】本発明における好ましい実施形態の一例を
図示により説明すれば、図１において、１は電解槽、２
は循環槽、３は循環ポンプ、４は冷却器、５は分液槽、
６は凝縮液がショートパスして電解槽に供給されないよ
うにするための内部堰、７は分液されたフッ化水素の供
給ライン、８は分液されたフッ素化生成物の抜き出しラ
イン、９はフッ素化生成物の抜き出し槽である。Referring to the drawings, an example of a preferred embodiment of the present invention will be described. In FIG.
Is a circulation tank, 3 is a circulation pump, 4 is a cooler, 5 is a separation tank,
Reference numeral 6 denotes an internal weir for preventing the condensed liquid from being supplied to the electrolytic cell through a short pass, 7 denotes a supply line for the separated hydrogen fluoride, 8 denotes a line for extracting the separated fluorinated product, 9 Is a tank for extracting fluorinated products.
【００２４】[0024]
【発明の効果】本発明によれば、循環を伴う電解フッ素
化方法において、電解槽から排出されるガス相を冷却し
て、ガス相中のフッ化水素とフッ素化生成物を凝縮した
のち分液して、フッ素化生成物の液相を被電解液に接触
させることなく分離して取り出し、フッ化水素の液相を
被電解液に戻すことにより、長期間にわたりフッ素化生
成物を高収率で得られ、かつ電解電圧が安定な状態で電
解フッ素化を実施することができる。According to the present invention, in the electrolytic fluorination method involving circulation, the gas phase discharged from the electrolytic cell is cooled, and hydrogen fluoride and fluorinated products in the gas phase are condensed and then separated. Liquid, separates and removes the liquid phase of the fluorinated product without coming into contact with the electrolyte, and returns the liquid phase of hydrogen fluoride to the electrolyte to obtain high yields of the fluorinated product over a long period of time. Rate, and the electrolytic fluorination can be carried out in a state where the electrolytic voltage is stable.
【００２５】本発明において、このような効果が発現す
る理由は明確ではないが、本発明者らは次のように推測
している。すなわち、フッ素化生成物の比重は、通常
１．５〜２．０程度である。これに対し、フッ化水素の
比重は１．０であり、被電解液の比重は通常１．１〜
１．４である。このため、フッ素化生成物と被電解液の
比重差が小さく、フッ素化生成物は被電解液と混合しや
すい。また、被電解液中には反応中間体である部分フッ
素化物や分解生成物、あるいは陽極から発生したフッ化
ニッケルが溶解あるいは分散しており、これが何らかの
親和性を有してフッ素化生成物は、被電解液に分散し易
い。混合あるいは分散したフッ素化生成物は、電解槽に
運ばれると分解され、収率の低下や安定運転の妨げを引
き起こす。これに対し、本発明では、電解槽から排出さ
れるガス相を冷却して、ガス相中のフッ化水素とフッ素
化生成物を凝縮したのち分液することで、比重差が大き
く、しかも容易に分離できるため、このような効果が発
現するものと推測している。In the present invention, the reason why such an effect is exhibited is not clear, but the present inventors speculate as follows. That is, the specific gravity of the fluorinated product is usually about 1.5 to 2.0. On the other hand, the specific gravity of hydrogen fluoride is 1.0, and the specific gravity of the electrolytic solution is usually 1.1 to
1.4. Therefore, the specific gravity difference between the fluorinated product and the electrolyte is small, and the fluorinated product is easily mixed with the electrolyte. Also, in the liquid to be electrolyzed, partially fluorinated products and decomposition products as reaction intermediates or nickel fluoride generated from the anode are dissolved or dispersed, and this has some affinity and the fluorinated products are Easily dispersed in the electrolyte solution. The mixed or dispersed fluorinated products are decomposed when transported to the electrolytic cell, which lowers the yield and hinders stable operation. On the other hand, in the present invention, the gas phase discharged from the electrolytic cell is cooled, hydrogen fluoride and fluorinated products in the gas phase are condensed, and then liquid separation is performed. Therefore, it is presumed that such an effect is exhibited.
【００２６】なお、ヘキサン等のアルカンの電解フッ素
化を実施する場合、ガス相に同伴したフッ素化生成物
を、フッ化水素と共に凝縮させて循環槽等に供給し、こ
こで被電解液から分離しようとすると、原料ヘキサンが
フッ素化生成物に溶解してしまい、原料ヘキサンの転化
率が極めて低くなる。この点、本発明に従えば、フッ素
化生成物に溶解しやすい有機化合物を用いた場合でも、
フッ素化生成物の収率を高めるだけでなく、原料有機化
合物の転化率を高めることもできる。When performing electrolytic fluorination of an alkane such as hexane, the fluorinated product accompanying the gas phase is condensed with hydrogen fluoride and supplied to a circulation tank or the like, where it is separated from the electrolytic solution. If this is attempted, the starting hexane will be dissolved in the fluorinated product, and the conversion of the starting hexane will be extremely low. In this regard, according to the present invention, even when an organic compound that is easily dissolved in a fluorinated product is used,
Not only can the yield of the fluorinated product be increased, but also the conversion of the starting organic compound can be increased.
【００２７】[0027]
【実施例】本発明をさらに具体的に説明するために以下
実施例を掲げるが、本発明はこれらの実施例に限定され
るものではない。EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.
【００２８】実施例１ 図１に示すようなＳＵＳ製電解槽、上部に凝縮器（−４
５℃）を有する循環槽（容量３．５リットル）、凝縮器
からの還流液であるフッ化水素とフッ素化生成物とを分
離する分離槽（容量２００ｍｌ、内部に堰を有する）か
らなる電解フッ素化装置を用いた。電極として、陽極お
よび陰極が交互に配置されたニッケル製電極（一枚１０
ｃｍ×８．５ｃｍ、陽極用３枚、陰極用４枚）を用い
た。Example 1 An electrolytic cell made of SUS as shown in FIG. 1 and a condenser (-4
Electrolysis consisting of a circulation tank having a capacity of 5 ° C. (3.5 liter capacity) and a separation tank (capacity: 200 ml, having a weir inside) for separating hydrogen fluoride as a reflux from the condenser and fluorinated products. A fluorinator was used. As an electrode, a nickel electrode (10 pieces per sheet) in which an anode and a cathode were alternately arranged.
cm × 8.5 cm, 3 sheets for the anode and 4 sheets for the cathode).
【００２９】フッ化水素とプロピルモルホリン（プロピ
ルモルホリンの濃度２０重量％）を原料とし、電解槽と
循環槽の間をポンプで循環しながら１０Ａ／ｄｍ2 の電
流密度で電解を開始した。循環流量は電極間の線速度を
７ｃｍ／ｓとなるように被電解液を流した。その後、１
０日間電解を行った。この間、電解電流に相当するフッ
化水素とプロピルモルホリンを連続的に供給しつつ、電
解槽と循環槽を外部から温度調節して被電解液の温度を
約３０℃に保った。また、凝縮器からの還流液量を測定
し、分離槽内においてフッ化水素とフッ素化生成物のそ
れぞれが滞在時間６０分となるようにオーバーフロー位
置を調整した。フッ化水素はオーバーフローにより循環
槽に連続的に供給し、フッ素化生成物もオーバーフロー
により連続的に受槽に取り出した。Electrolysis was started at a current density of 10 A / dm 2 while hydrogen fluoride and propyl morpholine (concentration of propyl morpholine: 20% by weight) were used as raw materials while circulating a pump between the electrolysis tank and the circulation tank. The electrolytic solution was flowed so that the circulating flow rate was such that the linear velocity between the electrodes was 7 cm / s. Then 1
Electrolysis was performed for 0 days. During this time, while continuously supplying hydrogen fluoride and propylmorpholine corresponding to the electrolytic current, the temperature of the electrolytic solution was maintained at about 30 ° C. by controlling the temperature of the electrolytic bath and the circulation bath from the outside. In addition, the amount of reflux liquid from the condenser was measured, and the overflow position was adjusted so that each of the hydrogen fluoride and the fluorinated product stayed in the separation tank for 60 minutes. Hydrogen fluoride was continuously supplied to the circulation tank by overflow, and fluorinated products were continuously taken out to the receiving tank by overflow.
【００３０】電解開始１０日後の電解電圧は５．４２Ｖ
であり、フッ素化生成物であるパーフルオロプロピルモ
ルホリン（沸点９７℃）の収率は７８％であった。この
のち、６０日間にわたって電解を継続したが、電解電圧
および収率は安定していた。なお、この間、循環槽下部
ならびに電解槽下部からフッ素化生成物を抜き出す必要
はなかった。The electrolysis voltage 10 days after the start of electrolysis is 5.42 V
And the yield of fluorinated product perfluoropropylmorpholine (boiling point 97 ° C.) was 78%. Thereafter, electrolysis was continued for 60 days, but the electrolysis voltage and the yield were stable. During this time, there was no need to extract the fluorinated products from the lower part of the circulation tank and the lower part of the electrolytic cell.
【００３１】さらにその後、比較のため、凝縮器からの
還流液を分離槽を経由せず、フッ化水素とフッ素化生成
物の全量を循環槽に戻し、循環槽下部からフッ素化生成
物を分離するように切り替えた。切り替え後、１５日間
電解を行ったが、電解電圧は５．６Ｖから５．９Ｖの間
を変動し、パーフルオロプロピルモルホリンの収率は５
１％から６３％の間を変動した。Then, for comparison, the reflux liquid from the condenser was not passed through the separation tank, but the entire amount of hydrogen fluoride and the fluorinated product was returned to the circulation tank, and the fluorinated product was separated from the lower part of the circulation tank. Switched to After the switching, electrolysis was performed for 15 days. The electrolysis voltage fluctuated between 5.6 V and 5.9 V, and the yield of perfluoropropylmorpholine was 5%.
It varied between 1% and 63%.
【００３２】実施例２ 実施例１において有機化合物としてヘキサンを用い、伝
導度増加剤としてヘキサンの１５重量部の二硫化メチル
を混合して用いた他は、実施例１と同様にヘキサンの電
解フッ素化を実施した。電解開始後２０日におけるペル
フルオロヘキサンの収率は４１％であった。またフッ素
化生成物中に原料ヘキサンが５％溶解していた。Example 2 The same procedure as in Example 1 was repeated except that hexane was used as the organic compound, and 15 parts by weight of hexane methyl disulfide was used as a conductivity-increasing agent. Was implemented. The yield of perfluorohexane 20 days after the start of electrolysis was 41%. Also, 5% of the starting hexane was dissolved in the fluorinated product.
【００３３】また、比較のため、凝縮器からの還流液を
分離槽を経由せず、フッ化水素とフッ素化生成物の全量
を循環槽に戻るように切り替え後、２０日後のペルフル
オロヘキサンの収率は２８％であった。またフッ素化生
成物中に原料ヘキサンが２３％溶解していた。Further, for comparison, the reflux liquid from the condenser was switched so that the total amount of hydrogen fluoride and the fluorinated product was returned to the circulation tank without passing through the separation tank, and the recovery of perfluorohexane 20 days later was performed. The rate was 28%. Also, 23% of the raw material hexane was dissolved in the fluorinated product.
【図１】図１は、本発明の実施形態の代表的態様を示す
概略図である。FIG. 1 is a schematic diagram illustrating a representative aspect of an embodiment of the present invention.
１：電解槽 ２：循環槽 ３：循環ポンプ ４：冷却器 ５：分液槽 ６：内部堰 ７：分液されたフッ化水素の供給ライン ８：分液されたフッ素化生成物の抜き出しライン ９：フッ素化生成物の抜き出し槽 1: Electrolysis tank 2: Circulation tank 3: Circulation pump 4: Cooler 5: Separation tank 6: Internal dam 7: Supply line of separated hydrogen fluoride 8: Extraction line of separated fluorinated product 9: Extraction tank for fluorinated products
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成８年１０月１１日[Submission date] October 11, 1996
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２９[Correction target item name] 0029
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【００２９】フッ化水素とＮ−プロピルモルホリン（Ｎ
−プロピルモルホリンの濃度２０重量％）を原料とし、
電解槽と循環槽の間をポンプで循環しながら１０Ａ／ｄ
ｍ2の電流密度で電解を開始した。循環流量は電極間の
線速度を７ｃｍ／ｓとなるように被電解液を流した。そ
の後、１０日間電解を行った。この間、電解電流に相当
するフッ化水素とＮ−プロピルモルホリンを連続的に供
給しつつ、電解槽と循環槽を外部から温度調節して被電
解液の温度を約３０℃に保った。また、凝縮器からの還
流液量を測定し、分離槽内においてフッ化水素とフッ素
化生成物のそれぞれが滞在時間６０分となるようにオー
バーフロー位置を調整した。フッ化水素はオーバーフロ
ーにより循環槽に連続的に供給し、フッ素化生成物もオ
ーバーフローにより連続的に受槽に取り出した。Hydrogen fluoride and N -propylmorpholine ( N
- the concentration of 20 wt%) of propyl morpholine as the raw material,
10A / d while circulating between the electrolytic cell and the circulation tank with a pump
Electrolysis was started at a current density of m2. The electrolytic solution was flowed so that the circulating flow rate was such that the linear velocity between the electrodes was 7 cm / s. Thereafter, electrolysis was performed for 10 days. During this time, while continuously supplying hydrogen fluoride and N -propylmorpholine corresponding to the electrolytic current, the temperature of the electrolytic solution was maintained at about 30 ° C. by controlling the temperature of the electrolytic bath and the circulation bath from the outside. In addition, the amount of reflux liquid from the condenser was measured, and the overflow position was adjusted so that each of the hydrogen fluoride and the fluorinated product stayed in the separation tank for 60 minutes. Hydrogen fluoride was continuously supplied to the circulation tank by overflow, and fluorinated products were continuously taken out to the receiving tank by overflow.
【手続補正２】[Procedure amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３０[Correction target item name] 0030
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【００３０】電解開始１０日後の電解電圧は５．４２Ｖ
であり、フッ素化生成物であるパーフルオロＮ−プロピ
ルモルホリン（沸点９７℃）の収率は７８％であった。
こののち、６０日間にわたって電解を継続したが、電解
電圧および収率は安定していた。なお、この間、循環槽
下部ならびに電解槽下部からフッ素化生成物を抜き出す
必要はなかった。The electrolysis voltage 10 days after the start of electrolysis is 5.42 V
And the yield of fluorinated product perfluoro N -propylmorpholine (boiling point 97 ° C.) was 78%.
Thereafter, electrolysis was continued for 60 days, but the electrolysis voltage and the yield were stable. During this time, there was no need to extract the fluorinated products from the lower part of the circulation tank and the lower part of the electrolytic cell.
【手続補正３】[Procedure amendment 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３１[Correction target item name] 0031
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【００３１】さらにその後、比較のため、凝縮器からの
還流液を分離槽を経由せず、フッ化水素とフッ素化生成
物の全量を循環槽に戻し、循環槽下部からフッ素化生成
物を分離するように切り替えた。切り替え後、１５日間
電解を行ったが、電解電圧は５．６Ｖから５．９Ｖの間
を変動し、パーフルオロＮ−プロピルモルホリンの収率
は５１％から６３％の間を変動した。Then, for comparison, the reflux liquid from the condenser was not passed through the separation tank, but the entire amount of hydrogen fluoride and the fluorinated product was returned to the circulation tank, and the fluorinated product was separated from the lower part of the circulation tank. Switched to After the switching, electrolysis was performed for 15 days. The electrolysis voltage fluctuated between 5.6 V and 5.9 V, and the yield of perfluoro N- propylmorpholine fluctuated between 51% and 63%.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図１[Correction target item name] Fig. 1
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図１】 FIG.
Claims (1)
液の一部を抜き出し、これを再度電解槽に循環させなが
ら、該電解槽中で有機化合物の電解フッ素化を行う方法
において、電解槽から排出されるガス相を冷却して該ガ
ス相中のフッ化水素およびフッ素化生成物を凝縮させ、
次いで得られた凝縮液をフッ化水素の液相とフッ素化生
成物の液相とに分液し、フッ化水素の液相を上記被電解
液に混合することを特徴とする電解フッ素化方法。1. A method for extracting a portion of a liquid to be electrolyzed containing an organic compound present in an electrolytic cell and circulating the extracted liquid again in the electrolytic cell while electrolytically fluorinating the organic compound in the electrolytic cell. Cooling the gas phase discharged from the vessel to condense the hydrogen fluoride and fluorinated products in the gas phase;
Then, the obtained condensate is separated into a liquid phase of hydrogen fluoride and a liquid phase of a fluorinated product, and the liquid phase of hydrogen fluoride is mixed with the liquid to be electrolyzed. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8266307A JPH10110284A (en) | 1996-10-07 | 1996-10-07 | Electrolytic fluorination method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8266307A JPH10110284A (en) | 1996-10-07 | 1996-10-07 | Electrolytic fluorination method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10110284A true JPH10110284A (en) | 1998-04-28 |
Family
ID=17429120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8266307A Pending JPH10110284A (en) | 1996-10-07 | 1996-10-07 | Electrolytic fluorination method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10110284A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003073873A (en) * | 2001-08-31 | 2003-03-12 | Permelec Electrode Ltd | Electrolytic fluorination method for organic ether compound |
| JP2006509831A (en) * | 2002-12-16 | 2006-03-23 | スリーエム イノベイティブ プロパティズ カンパニー | Method for producing fluoroolefin |
| JP2006348381A (en) * | 2005-05-17 | 2006-12-28 | Asahi Kasei Corp | Method for producing organic compound by electrolytic fluoridation |
| WO2023249374A1 (en) * | 2022-06-21 | 2023-12-28 | 에스케이스페셜티 주식회사 | Apparatus and method for producing pftpa by using electrochemical fluorination |
-
1996
- 1996-10-07 JP JP8266307A patent/JPH10110284A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003073873A (en) * | 2001-08-31 | 2003-03-12 | Permelec Electrode Ltd | Electrolytic fluorination method for organic ether compound |
| JP2006509831A (en) * | 2002-12-16 | 2006-03-23 | スリーエム イノベイティブ プロパティズ カンパニー | Method for producing fluoroolefin |
| JP2006348381A (en) * | 2005-05-17 | 2006-12-28 | Asahi Kasei Corp | Method for producing organic compound by electrolytic fluoridation |
| WO2023249374A1 (en) * | 2022-06-21 | 2023-12-28 | 에스케이스페셜티 주식회사 | Apparatus and method for producing pftpa by using electrochemical fluorination |
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