JPH09255597A - Purification of pentafluoroethane - Google Patents
Purification of pentafluoroethaneInfo
- Publication number
- JPH09255597A JPH09255597A JP6657696A JP6657696A JPH09255597A JP H09255597 A JPH09255597 A JP H09255597A JP 6657696 A JP6657696 A JP 6657696A JP 6657696 A JP6657696 A JP 6657696A JP H09255597 A JPH09255597 A JP H09255597A
- Authority
- JP
- Japan
- Prior art keywords
- fluorinated hydrocarbon
- formula
- pentafluoroethane
- column
- chloropentafluoroethane
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/38—Separation; Purification; Stabilisation; Use of additives
- C07C17/383—Separation; Purification; Stabilisation; Use of additives by distillation
- C07C17/386—Separation; Purification; Stabilisation; Use of additives by distillation with auxiliary compounds
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、クロロペンタフル
オロエタンＣ2 Ｆ5 Ｃｌを含むペンタフルオロエタンＣ
2 ＨＦ5 からＣ2 ＨＦ5 を分離して高純度のＣ2 ＨＦ5
を得る精製方法に関する。TECHNICAL FIELD The present invention relates to a pentafluoroethane C containing chloropentafluoroethane C 2 F 5 Cl.
C 2 HF 5 of high purity was obtained by separating C 2 HF 5 from 2 HF 5.
To a purification method for obtaining
【０００２】[0002]
【従来の技術】クロロジフルオロエタンＣＨＦ2 Ｃｌ
は、オゾン層を破壊し人類を含めた生態系に悪影響を与
えるとの理由でのその使用を削減し、将来的には全廃す
ることが決まっている。その代替冷媒としてＣ2 ＨＦ5
は注目されており、ジフルオロメタンＣＨ2 Ｆ2 、１，
１，１−トリフルオロエタンＣＨ3 ＣＦ3 、１，１，
１，２−テトラフルオロエタンＣＨ2 ＦＣＦ3 などとの
混合冷媒も各種提案されている。 2. Description of the Related Art Chlorodifluoroethane CHF 2 Cl
Has decided to reduce its use because it destroys the ozone layer and adversely affects ecosystems including humankind, and will abolish it in the future. C 2 HF 5 as an alternative refrigerant
Has attracted attention, and difluoromethane CH 2 F 2 , 1,
1,1-trifluoroethane CH 3 CF 3 , 1,1,
Various mixed refrigerants with 1,2-tetrafluoroethane CH 2 FCF 3 and the like have been proposed.
【０００３】Ｃ2 ＨＦ5 の製造方法としては、種々の方
法が従来より知られている。通常、パークロロエチレン
を原料として、中間体１，１−ジクロロ−２，２，２−
トリフルオロエタンＣＨＣｌ2 ＣＦ3 や１−クロロ−
１，２，２，２−テトラフルオロエタンＣＨＦＣｌＣＦ
3 を得、これらの気相フッ素化などのプロセスにより得
るか、Ｃ2 Ｆ5 Ｃｌを脱塩素水素化して得る製造方法が
知られている。いずれの場合もその反応粗ガスを蒸留分
離すると、Ｃ2 ＨＦ5 の主留には、不純物としてＣ2 Ｆ
5 Ｃｌが含まれる。Various methods have been conventionally known as methods for producing C 2 HF 5 . Usually, the intermediate 1,1-dichloro-2,2,2-using perchlorethylene as a raw material
Trifluoroethane CHCl 2 CF 3 and 1-chloro-
1,2,2,2-tetrafluoroethane CHFCClCF
There is known a production method in which 3 is obtained and obtained by a process such as vapor phase fluorination, or C 2 F 5 Cl is dechlorinated and hydrogenated. In either case, when the reaction crude gas is separated by distillation, the main fraction of C 2 HF 5 contains C 2 F as an impurity.
5 Cl is included.
【０００４】Ｃ2 ＨＦ5 中のＣ2 Ｆ5 Ｃｌを分離する方
法には、Ｃ2 Ｆ5 Ｃｌを水素還元してＣ2 ＨＦ5 にする
方法（ＷＯ９４／０２４３９、ＷＯ９４／２０４４１）
やＣ2 Ｆ5 Ｃｌをフッ素化してヘキサフルオロエタンＣ
2 Ｆ6 にし、これとＣ2 ＨＦ5 を分離する方法（特開平
６−２５６２３４）が提案されている。[0004] The method of separating the C 2 F 5 Cl in C 2 HF 5, how to C 2 HF 5 by hydrogen reduction of C 2 F 5 Cl (WO94 / 02439, WO94 / 20441)
Hexafluoroethane C by fluorinating or C 2 F 5 Cl
A method has been proposed in which 2 F 6 is used and C 2 HF 5 is separated from this (JP-A-6-256234).
【０００５】Ｃ2 Ｆ5 Ｃｌの水素還元では、Ｃ2 Ｆ5 Ｃ
ｌの転化率を１００％としない限りＣ2 Ｆ5 Ｃｌが残存
する。Ｃ2 Ｆ5 Ｃｌを充分反応させるためには、水素の
過剰率を上げる必要がある。しかし、これにより未反応
水素が多くなり、Ｃ2 ＨＦ5の回収率が低下し、工業的
な規模では実質的なＣ2 ＨＦ5 の回収は困難となる。Ｃ
2 Ｆ5 ＣｌのＣ2 Ｆ6 へのフッ素化は、厳しい反応条件
を必要とするためＣ2ＨＦ5 が分解し、精製法として適
当ではない。In the hydrogen reduction of C 2 F 5 Cl, C 2 F 5 C
Unless the conversion rate of 1 is 100%, C 2 F 5 Cl remains. In order to sufficiently react C 2 F 5 Cl, it is necessary to increase the excess ratio of hydrogen. However, due to this, the amount of unreacted hydrogen increases, the recovery rate of C 2 HF 5 decreases, and it becomes difficult to recover C 2 HF 5 substantially on an industrial scale. C
The fluorination of 2 F 5 Cl to C 2 F 6 is not suitable as a purification method because it requires severe reaction conditions and C 2 HF 5 decomposes.
【０００６】そこで、上記問題の解決方法として、Ｃ2
Ｆ5 Ｃｌを含むＣ2 ＨＦ5 を抽出蒸留により分離する提
案がされている。Therefore, as a solution to the above problem, C 2
It has been proposed to separate C 2 HF 5 containing F 5 Cl by extractive distillation.
【０００７】抽出媒体として、−３９〜＋５０℃の沸点
を有する炭素数１〜４のフッ素化炭化水素（水素、塩素
を任意に含んでもよい）が提案されている（特表平６−
５１０９８０）。しかし、この抽出媒体の大部分はオゾ
ン層保護法に基づく規制物質であること、規制物質でな
いオクタフルオロシクロブタンにあっては容易に製造し
にくいことなどの欠点がある。As the extraction medium, a fluorinated hydrocarbon having a boiling point of -39 to + 50 ° C. and having 1 to 4 carbon atoms (which may optionally contain hydrogen or chlorine) has been proposed (Table 6-
510980). However, most of this extraction medium has drawbacks such as being a regulated substance based on the ozone layer protection law, and octafluorocyclobutane, which is not a regulated substance, is difficult to easily manufacture.
【０００８】抽出媒体として、−１０〜＋１００℃の沸
点を有するパラフィン系炭化水素、アルコール、エーテ
ル、エステル、ケトンも提案がされている（特開平７−
１３３２４０）。しかし、この抽出媒体は、可燃性物質
であること、およびＣ2 ＨＦ5 とＣ2 Ｆ5 Ｃｌの分離効
率が不充分であることなどの欠点がある。Paraffin hydrocarbons having a boiling point of -10 to + 100 ° C, alcohols, ethers, esters and ketones have also been proposed as extraction media (Japanese Patent Laid-Open No. 7-
133240). However, this extraction medium is disadvantageous in that it is a flammable substance and that the separation efficiency of C 2 HF 5 and C 2 F 5 Cl is insufficient.
【０００９】[0009]
【発明が解決しようとする課題】本発明の目的は、安価
に入手可能であり、使用条件下で安定かつ難燃性であ
り、かつ、環境に対しての影響が小さいという優れた抽
出媒体によるペンタフルオロエタンの精製方法を提供す
ることである。The object of the present invention is to provide an excellent extraction medium that is inexpensively available, stable and flame-retardant under the conditions of use, and has a small impact on the environment. It is to provide a method for purifying pentafluoroethane.
【００１０】[0010]
【課題を解決するための手段】本発明は、クロロペンタ
フルオロエタンを含むペンタフルオロエタンに、式１ま
たは式２で表されるフッ素化炭化水素を接触させて、ク
ロロペンタフルオロエタンを前記式１または式２で表さ
れるフッ素化炭化水素に吸収させ、ペンタフルオロエタ
ン中のクロロペンタフルオロエタンを除去することを特
徴とするペンタフルオロエタンの精製方法である。 Ｃn Ｈa Ｆ2n+2-a・・・式１ Ｃn Ｈb Ｆ2n-b ・・・式２ （ただし、式１および式２において、ｎは５〜１２の整
数、ａは０≦ａ≦ｎ＋２を満たす整数、ｂは０≦ｂ≦ｎ
＋１を満たす整数。）。According to the present invention, pentafluoroethane containing chloropentafluoroethane is brought into contact with a fluorinated hydrocarbon represented by Formula 1 or Formula 2 to convert chloropentafluoroethane to Formula 1 Alternatively, it is a method for purifying pentafluoroethane, which comprises absorbing chlorofluorofluoroethane in pentafluoroethane by absorbing it with a fluorinated hydrocarbon represented by Formula 2. C n H a F 2n + 2 -a ··· Formula 1 C n H b F 2n- b ··· formula 2 (wherein, in Formula 1 and Formula 2, n is 5 to 12 integer, a is 0 ≦ An integer satisfying a ≦ n + 2, b is 0 ≦ b ≦ n
An integer that satisfies +1. ).
【００１１】Ｃ2 ＨＦ5 中のＣ2 Ｆ5 Ｃｌは、ＣＨＣｌ
2 ＣＦ3 やＣＨＦＣｌＣＦ3 の気相フッ素化によるＣ2
ＨＦ5 の製造時およびＣ2 Ｆ5 Ｃｌの脱塩素水素化によ
るＣ2 ＨＦ5 の製造時などに副生されるものである。C 2 F 5 Cl in C 2 HF 5 is CHCl
C 2 by vapor phase fluorination of 2 CF 3 and CHFClCF 3
It is a by-product at the time of producing HF 5 and at the time of producing C 2 HF 5 by dehydrochlorination of C 2 F 5 Cl.
【００１２】Ｃ2 ＨＦ5 中のＣ2 Ｆ5 Ｃｌの割合は、上
記の製法などで得たＣ2 ＨＦ5 中に含まれるＣ2 Ｆ5 Ｃ
ｌの割合であり、通常Ｃ2 ＨＦ5 の１００重量部に対し
てＣ2 Ｆ5 Ｃｌが０．０１〜４０重量部の割合である。
Ｃ2 ＨＦ5 中にはＣ2 Ｆ5 Ｃｌ以外に他の化合物が含ま
れていてもよい。[0012] C 2 C 2 ratio of F 5 Cl of HF in 5, C 2 F 5 C contained in C 2 HF 5 obtained by such above method
It is a ratio of 1 and usually 0.01 to 40 parts by weight of C 2 F 5 Cl to 100 parts by weight of C 2 HF 5 .
C 2 HF 5 may contain other compounds in addition to C 2 F 5 Cl.
【００１３】Ｃ2 Ｆ5 Ｃｌを含むＣ2 ＨＦ5 に、式１ま
たは式２で表されるフッ素化炭化水素（以下、まとめて
フッ素化炭化水素Ａという）を接触させ、Ｃ2 Ｆ5 Ｃｌ
をフッ素化炭化水素Ａ中に取り込むことにより、Ｃ2 Ｆ
5 ＣｌとＣ2 ＨＦ5 を分離しＣ2 ＨＦ5 を回収する。一
方、Ｃ2 Ｆ5 Ｃｌを含むフッ素化炭化水素Ａは加熱され
ることにより、Ｃ2 Ｆ5 Ｃｌを発生させてフッ素化炭化
水素ＡないしＣ2 Ｆ5Ｃｌを回収する。C 2 HF 5 containing C 2 F 5 Cl is brought into contact with the fluorinated hydrocarbon represented by Formula 1 or Formula 2 (hereinafter collectively referred to as fluorinated hydrocarbon A) to give C 2 F 5 Cl.
By incorporating in the fluorinated hydrocarbon A, C 2 F
5 Cl and C 2 HF 5 are separated and C 2 HF 5 is recovered. On the other hand, fluorinated hydrocarbons A containing C 2 F 5 Cl is by being heated, to no fluorinated hydrocarbon A by generating C 2 F 5 Cl recovering C 2 F 5 Cl.
【００１４】本発明におけるフッ素化炭化水素Ａは、１
９９６年以降その使用が規制される特定フロンと異なり
オゾン層破壊を起こす可能性が低いため環境への影響が
小さいこと、また分子内の水素数が、炭素数＋２までに
抑えられているため、不燃性であるか燃焼範囲を有して
いても引火点をもたないなどの特徴を有する。The fluorinated hydrocarbon A in the present invention is 1
Unlike specific CFCs whose use is regulated after 996, the possibility of ozone layer depletion is low, so the impact on the environment is small, and the number of hydrogen atoms in the molecule is suppressed to +2 carbon atoms, It has the feature that it does not have a flash point even if it is nonflammable or has a burning range.
【００１５】式１または式２において、ｎ、ａおよびｂ
の範囲は、フッ素化炭化水素Ａが常温で液状を呈し、抽
出媒体としても充分な相対揮発度を有する化合物となる
ものから選ばれ、ｎは５〜１２の整数である。ｎは６〜
９の整数であることが、また、式１で表されるフッ素化
炭化水素であることが、性能面、入手容易性などの点か
ら好ましい。In Formula 1 or Formula 2, n, a and b
The range is selected from those in which the fluorinated hydrocarbon A is liquid at room temperature and is a compound having a sufficient relative volatility as an extraction medium, and n is an integer of 5 to 12. n is 6 to
An integer of 9 and a fluorinated hydrocarbon represented by Formula 1 are preferable from the viewpoints of performance, availability, and the like.
【００１６】具体的には、式１で表されるフッ素化炭化
水素として、Ｃ6 Ｆ14、Ｃ6 ＨＦ13、Ｃ6 Ｈ2 Ｆ12が、
式２で表されるフッ素化炭化水素として、Ｃ6 Ｆ12、Ｃ
9 Ｆ18が好ましいものとして挙げられる。フッ素化炭化
水素Ａは、炭素数および／またはフッ素数の異なる２種
以上を併用してもよい。また、フッ素化炭化水素Ａは、
本発明における抽出媒体としての機能を損なわないかぎ
り、１種以上の異性体が含まれた混合物でもよい。Specifically, as the fluorinated hydrocarbon represented by the formula 1, C 6 F 14 , C 6 HF 13 and C 6 H 2 F 12 are
As the fluorinated hydrocarbon represented by the formula 2, C 6 F 12 , C
9 F 18 is mentioned as a preferable one. As the fluorinated hydrocarbon A, two or more kinds having different carbon numbers and / or fluorine numbers may be used in combination. Further, the fluorinated hydrocarbon A is
A mixture containing one or more isomers may be used as long as the function as the extraction medium in the present invention is not impaired.
【００１７】Ｃ2 Ｆ5 Ｃｌを含むＣ2 ＨＦ5 に、フッ素
化炭化水素Ａを接触させる方法としては特に限定されな
いが、工業的に実施する場合には、以下の方法で連続的
に実施するのが好ましい。The method of contacting the fluorinated hydrocarbon A with C 2 HF 5 containing C 2 F 5 Cl is not particularly limited, but in the case of industrial implementation, it is continuously conducted by the following method. Is preferred.
【００１８】すなわち、２０〜８０段の理論段数を有す
る蒸留塔を準備し、該蒸留塔の中段にＣ2 Ｆ5 Ｃｌを含
むＣ2 ＨＦ5 を供給する。そして、蒸留塔頂付近にフッ
素化炭化水素Ａを供給し、上部から下部へ流す。フッ素
化炭化水素Ａに対しＣ2 Ｆ5Ｃｌより少なく溶解するＣ2
ＨＦ5 は、濃縮された状態で蒸留塔頂部より除かれ
る。一方、Ｃ2 Ｆ5 Ｃｌを含むフッ素化炭化水素Ａは、
理論段数が通常５〜５０段の別の蒸留塔に導かれ、Ｃ2
Ｆ5 Ｃｌとフッ素化炭化水素Ａとに分離される。別の蒸
留塔で分離したフッ素化炭化水素Ａは、再び冷却され
て、吸収塔の頂部に再循環する。蒸留塔の形式は、充填
塔型または泡鐘塔型が好ましい。[0018] That is, to prepare a distillation column having a theoretical plate number of 20 to 80 stages, supplies C 2 HF 5 containing C 2 F 5 Cl in the middle of the distillation column. Then, the fluorinated hydrocarbon A is supplied near the top of the distillation column and flows from the upper part to the lower part. C 2 which dissolves less than C 2 F 5 Cl in fluorinated hydrocarbon A
HF 5 is removed from the top of the distillation column in a concentrated state. On the other hand, the fluorinated hydrocarbon A containing C 2 F 5 Cl is
Number of theoretical plates is introduced into another distillation column usually 5-50 stages, C 2
It is separated into F 5 Cl and fluorinated hydrocarbon A. The fluorinated hydrocarbon A separated in another distillation column is cooled again and recirculated to the top of the absorption column. The type of distillation column is preferably a packed column type or a bubble column type.
【００１９】Ｃ2 Ｆ5 Ｃｌを含むＣ2 ＨＦ5 に接触させ
るフッ素化炭化水素Ａの量は、Ｃ2Ｆ5 Ｃｌを含むＣ2
ＨＦ5 の１重量部に対して１〜１０００重量部程度が好
ましく、特に５〜５０重量部程度が好ましい。The amount of fluorinated hydrocarbon A into contact with the C 2 HF 5 containing C 2 F 5 Cl is, C 2 comprising C 2 F 5 Cl
About 1 to 1000 parts by weight is preferable, and about 5 to 50 parts by weight is particularly preferable for 1 part by weight of HF 5 .
【００２０】Ｃ2 Ｆ5 Ｃｌを含むＣ2 ＨＦ5 に、フッ素
化炭化水素Ａを接触させる際の圧力は特に限定されず、
最大圧力がＣ2 ＨＦ5 とＣ2 Ｆ5 Ｃｌの液化圧力未満で
あればよく、通常は、０．５〜１０気圧（絶対圧) 程度
が好ましい。また、温度も特に限定されず、使用するフ
ッ素化炭化水素Ａによって異なるが、通常は−３０〜＋
２００℃程度である。The pressure when the fluorinated hydrocarbon A is brought into contact with C 2 HF 5 containing C 2 F 5 Cl is not particularly limited,
The maximum pressure may be less than the liquefaction pressure of C 2 HF 5 and C 2 F 5 Cl, and normally about 0.5 to 10 atm (absolute pressure) is preferable. Further, the temperature is not particularly limited, and varies depending on the fluorinated hydrocarbon A used, but it is usually -30 to +.
It is about 200 ° C.
【００２１】フッ素化炭化水素Ａを加熱してＣ2 Ｆ5 Ｃ
ｌを発生させる際の圧力および温度も特に限定されず、
温度はフッ素化炭化水素Ａの還流温度程度が好ましい。The fluorinated hydrocarbon A is heated to C 2 F 5 C
The pressure and temperature for generating 1 are not particularly limited, either.
The temperature is preferably about the reflux temperature of the fluorinated hydrocarbon A.
【００２２】[0022]
【実施例】以下に、実施例（例１〜３）および比較例
（例４〜６）を挙げて具体的に説明するが、これらによ
って本発明は限定されない。なお、以下の例において
は、フッ素化炭化水素Ａの有効性をＣ2 Ｆ5 ＣｌとＣ2
ＨＦ5 の相対揮発度、リサイクル時の抽出媒体の安定性
をｐＨ試験紙による酸分発生の有無、安全性を引火点を
用いて評価した。EXAMPLES The present invention will be specifically described below with reference to Examples (Examples 1 to 3) and Comparative Examples (Examples 4 to 6), but the present invention is not limited thereto. In the examples below, the effectiveness of the fluorinated hydrocarbon A is shown as C 2 F 5 Cl and C 2
The relative volatility of HF 5 and the stability of the extraction medium at the time of recycling were evaluated by the presence or absence of acid content generated by pH test paper, and the safety was evaluated using the flash point.
【００２３】［相対揮発度の測定方法］オスマー型の加
圧平衡蒸留装置を用いて、約１０００ｐｐｍのＣ2 Ｆ5
Ｃｌを含むＣ2 ＨＦ5 、およびＣ6 Ｆ14などのフッ素化
炭化水素Ａを仕込み、釜を加熱し３〜６時間循環させ
た。その後、気相部の凝縮液と釜の液相部分の液を採取
し、ガスクロマトグラフにより、Ｃ2 ＨＦ5 とＣ2 Ｆ5
Ｃｌのモル比を測定し、Ｃ2 Ｆ5 Ｃｌに対するＣ2 ＨＦ
5 の相対揮発度を求めた。[Measurement Method of Relative Volatility] Using an Osmer type pressure equilibrium distillation apparatus, about 1000 ppm of C 2 F 5 was used.
Fluorinated hydrocarbon A such as C 2 HF 5 containing Cl and C 6 F 14 was charged, and the kettle was heated and circulated for 3 to 6 hours. After that, the condensate in the vapor phase and the liquid in the liquid phase in the kettle are sampled and analyzed by gas chromatography with C 2 HF 5 and C 2 F 5
Measuring the molar ratio of Cl, C 2 HF for C 2 F 5 Cl
A relative volatility of 5 was determined.
【００２４】［例１］オスマー型の加圧平衡蒸留装置を
用いて、Ｃ6 Ｆ14を１１１９ｇ、および１０００ｐｐｍ
のＣ2 Ｆ5 Ｃｌを含むＣ2 ＨＦ5 を５８ｇを仕込み上記
の測定方法により気液平衡を求めた結果、Ｃ2 ＨＦ5 に
対するＣ2 Ｆ5 Ｃｌの相対揮発度は０．５８であった。
結果を表１に示す。[Example 1] Using an Osmer type pressure equilibrium distillation apparatus, 1119 g of C 6 F 14 and 1000 ppm of C 6 F 14 were used.
C 2 F 5 and C 2 HF 5 containing Cl were charged 58g above measurement method results obtained vapor-liquid equilibrium by the relative volatility of C 2 F 5 Cl for C 2 HF 5 was 0.58 .
The results are shown in Table 1.
【００２５】抽出蒸留システムは、抽出蒸留塔と溶剤回
収塔の２塔から構成されるものを用いた。抽出蒸留塔は
さらに、溶剤回収部、濃縮部、回収部の３つに分割され
る。溶剤回収部の段数約５段、濃縮部の段数約３０段、
回収部約９段の蒸留塔に、Ｃ2 Ｆ5 Ｃｌを０．５モル％
含むＣ2 ＨＦ5 を濃縮部下部から毎時２５０ｇで連続的
に供給し、また、溶剤回収部下部よりＣ6 Ｆ14を毎時１
５００ｇ送り込み、塔底より毎時１５０４ｇ、塔頂より
毎時２４６ｇで連続的に抜き出し、還流比１０に制御し
つつ抽出蒸留を行った。このときの系内の圧力は６ｋｇ
Ｇ／ｃｍ2 であり、塔頂温度は３３℃、塔底温度は７５
℃であった。The extractive distillation system used was composed of two columns, an extractive distillation column and a solvent recovery column. The extractive distillation column is further divided into a solvent recovery section, a concentration section, and a recovery section. 5 stages of solvent recovery section, 30 stages of concentration section,
0.5 mol% of C 2 F 5 Cl was added to the distillation column of about 9 stages in the recovery section.
Containing C 2 HF 5 is continuously supplied from the lower part of the concentration section at 250 g / h, and C 6 F 14 is supplied from the lower part of the solvent recovery section at 1 hour / h.
500 g were fed, 1504 g / hr from the column bottom and 246 g / hr from the column top were continuously withdrawn, and extractive distillation was performed while controlling the reflux ratio to 10. The pressure in the system at this time is 6 kg
G / cm 2 , column top temperature is 33 ° C., column bottom temperature is 75
° C.
【００２６】塔頂と塔底から試料を採取して分析した結
果、Ｃ6 Ｆ14を除くＣ2 ＨＦ5 とＣ2 Ｆ5 Ｃｌのモル分
率で、塔頂からは９９．９５％のＣ2 ＨＦ5 が得られ、
塔底からは２９％のＣ2 Ｆ5 Ｃｌが得られた。As a result of collecting and analyzing samples from the top and bottom of the column, the molar fraction of C 2 HF 5 and C 2 F 5 Cl excluding C 6 F 14 was obtained. 2 HF 5 is obtained,
From the bottom of the column, 29% of C 2 F 5 Cl was obtained.
【００２７】塔底より得られる高濃度のＣ2 Ｆ5 Ｃｌと
Ｃ2 ＨＦ5 をモル分率で０．３％溶解しているＣ6 Ｆ14
を約２０段の段数をもつ溶剤回収塔の下から第３段目に
供給し、還流比を１０に制御しながら回収蒸留を行っ
た。このとき系内の圧力は０．５ｋｇＧ／ｃｍ2 であ
り、塔頂温度は−３０℃、塔底温度は６０℃であった。C 6 F 14 in which a high concentration of C 2 F 5 Cl and C 2 HF 5 obtained from the bottom of the column is dissolved by 0.3% in molar fraction
Was supplied to the third stage from the bottom of the solvent recovery column having about 20 stages, and recovery distillation was performed while controlling the reflux ratio to 10. At this time, the pressure in the system was 0.5 kgG / cm 2 , the column top temperature was −30 ° C., and the column bottom temperature was 60 ° C.
【００２８】塔頂と塔底から試料を採取してガスクロマ
トグラフで分析した結果、塔頂からはモル分率で９９．
９９９％以上の純度でＣ2 ＨＦ5 が毎時４ｇで得られ、
塔底からはモル分率で９９．９％以上のＣ6 Ｆ14が毎時
１５００ｇで得られた。このＣ6 Ｆ14に酸分の発生は認
められなかった。得られたＣ6 Ｆ14を抽出蒸留塔へ再循
環させた。Samples were taken from the top and bottom of the column and analyzed by gas chromatography, and as a result, the molar fraction from the top was 99.
C 2 HF 5 was obtained at a purity of 999% or more at 4 g / h,
From the bottom of the column, C 6 F 14 with a mole fraction of 99.9% or more was obtained at 1500 g / hr. No acid content was found in this C 6 F 14 . The C 6 F 14 obtained was recycled to the extractive distillation column.
【００２９】なお、Ｃ6 Ｆ14は、ＣＦ3 （ＣＦ2 ）4 Ｃ
Ｆ3 ／ＣＦ3 （ＣＦ2 ）2 ＣＦ（ＣＦ3 ）2 ／（ＣＦ3
ＣＦ2 ）2 ＣＦＣＦ3 ＝６９重量％／２７重量％／４重
量％の混合物であった。C 6 F 14 is CF 3 (CF 2 ) 4 C
F 3 / CF 3 (CF 2 ) 2 CF (CF 3 ) 2 / (CF 3
CF 2 ) 2 CFCF 3 = 69 wt% / 27 wt% / 4 wt% mixture.
【００３０】［例２〜３］表１に示す抽出媒体をそれぞ
れ用いて相対揮発度を求めた。また、例１と同一の装置
および方法で抽出蒸留を行った。結果を表１に示す。抽
出媒体は、いずれも引火点を持たないものである。Ｃ6
ＨＦ13は、ｎ−Ｃ6 ＨＦ13とその異性体からなる混合物
で、ｎ−Ｃ6 ＨＦ13を９９重量％以上含むものであっ
た。[Examples 2 to 3] The relative volatility of each of the extraction media shown in Table 1 was determined. In addition, extractive distillation was performed using the same apparatus and method as in Example 1. The results are shown in Table 1. None of the extraction media has a flash point. C 6
HF 13 was a mixture of n-C 6 HF 13 and its isomer, and contained 99% by weight or more of n-C 6 HF 13 .
【００３１】Ｃ6 Ｈ2 Ｆ12は、ＣＦ3 ＣＦ（ＣＦ3 ）Ｃ
ＨＦＣＨＦＣＦ3 とその異性体からなる混合物で、ＣＦ
3 ＣＦ（ＣＦ3 ）ＣＨＦＣＨＦＣＦ3 を７７重量％以上
含むものであった。C 6 H 2 F 12 is CF 3 CF (CF 3 ) C
A mixture of HFCHFCF 3 and its isomers, CF
3 was comprised of CF (CF 3) CHFCHFCF 3 to 77% by weight or more.
【００３２】［例４〜６］表１に示す抽出媒体をそれぞ
れ用いて相対揮発度を求めた。ジクロロメタンおよびメ
タノールでは、相対揮発度は１を超える、すなわちＣ2
Ｆ5 ＣｌよりＣ2ＨＦ5 がより吸収されやすい。また、
メタノールおよびｎ−ヘキサンは可燃性であり、引火点
を有する化合物である。[Examples 4 to 6] The relative volatility was determined using each of the extraction media shown in Table 1. In dichloromethane and methanol, the relative volatility is greater than 1, ie C 2
C 2 HF 5 is more easily absorbed than F 5 Cl. Also,
Methanol and n-hexane are flammable and flash point compounds.
【００３３】[0033]
【表１】 [Table 1]
【００３４】[0034]
【発明の効果】本発明によれば、従来の抽出媒体と同様
の相対揮発度を有する抽出媒体によりＣ2 ＨＦ5 および
Ｃ2 Ｆ5 Ｃｌの抽出蒸留ができる。本発明の抽出媒体は
安定であり、Ｃ2 ＨＦ5 およびＣ2 Ｆ5 Ｃｌと反応する
おそれもなく、分離効果にも優れ、引火点の問題もな
い。また、容易に入手でき、かつオゾン層等の環境に対
しての影響の少ない化合物であり、規制を受けていない
ものである。したがって、本発明は実用的であり、操作
が容易で、分離効果にも優れた方法である。According to the present invention, C 2 HF 5 and C 2 F 5 Cl can be subjected to extractive distillation by using an extraction medium having a relative volatility similar to that of conventional extraction media. The extraction medium of the present invention is stable, has no risk of reacting with C 2 HF 5 and C 2 F 5 Cl, has an excellent separation effect, and has no flash point problem. Further, it is a compound that is easily available and has little influence on the environment such as the ozone layer, and is not regulated. Therefore, the present invention is a method that is practical, easy to operate, and excellent in separation effect.
Claims (4)
フルオロエタンに、式１または式２で表されるフッ素化
炭化水素を接触させて、クロロペンタフルオロエタンを
前記式１または式２で表されるフッ素化炭化水素に吸収
させ、ペンタフルオロエタン中のクロロペンタフルオロ
エタンを除去することを特徴とするペンタフルオロエタ
ンの精製方法。 Ｃn Ｈa Ｆ2n+2-a・・・式１ Ｃn Ｈb Ｆ2n-b ・・・式２ （ただし、式１および式２において、ｎは５〜１２の整
数、ａは０≦ａ≦ｎ＋２を満たす整数、ｂは０≦ｂ≦ｎ
＋１を満たす整数。）1. A fluorinated hydrocarbon represented by formula 1 or 2 is brought into contact with pentafluoroethane containing chloropentafluoroethane to give chloropentafluoroethane represented by the formula 1 or 2 A method for purifying pentafluoroethane, which comprises absorbing chloropentafluoroethane in pentafluoroethane by absorbing it with a modified hydrocarbon. C n H a F 2n + 2 -a ··· Formula 1 C n H b F 2n- b ··· formula 2 (wherein, in Formula 1 and Formula 2, n is 5 to 12 integer, a is 0 ≦ An integer satisfying a ≦ n + 2, b is 0 ≦ b ≦ n
An integer that satisfies +1. )
13またはＣ6 Ｈ2 Ｆ12である請求項１の精製方法。2. A fluorinated hydrocarbon is C 6 F 14 or C 6 HF.
The purification method according to claim 1, which is 13 or C 6 H 2 F 12 .
ルオロエタンを含むペンタフルオロエタン１重量部に対
して１〜１０００重量部である請求項１または２の精製
方法。3. The purification method according to claim 1, wherein the amount of the fluorinated hydrocarbon is 1-1000 parts by weight with respect to 1 part by weight of pentafluoroethane containing chloropentafluoroethane.
フルオロエタンがペンタフルオロエタン１００重量部に
対してクロロペンタフルオロエタンを０．０１〜４０重
量部の割合で含むものである請求項１、２または３の精
製方法。4. The method according to claim 1, wherein the pentafluoroethane containing chloropentafluoroethane contains 0.01 to 40 parts by weight of chloropentafluoroethane with respect to 100 parts by weight of pentafluoroethane. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6657696A JPH09255597A (en) | 1996-03-22 | 1996-03-22 | Purification of pentafluoroethane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6657696A JPH09255597A (en) | 1996-03-22 | 1996-03-22 | Purification of pentafluoroethane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09255597A true JPH09255597A (en) | 1997-09-30 |
Family
ID=13319929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6657696A Pending JPH09255597A (en) | 1996-03-22 | 1996-03-22 | Purification of pentafluoroethane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09255597A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999010302A1 (en) * | 1997-08-21 | 1999-03-04 | Daikin Industries, Ltd. | Process for preparing pentafluoroethane |
| WO2012105700A1 (en) * | 2011-02-04 | 2012-08-09 | 旭硝子株式会社 | Method for purifying 2,3,3,3-tetrafluoropropene |
-
1996
- 1996-03-22 JP JP6657696A patent/JPH09255597A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999010302A1 (en) * | 1997-08-21 | 1999-03-04 | Daikin Industries, Ltd. | Process for preparing pentafluoroethane |
| US6527917B1 (en) | 1997-08-21 | 2003-03-04 | Daikin Industries Ltd. | Process for preparing pentafluoroethane |
| JP4529287B2 (en) * | 1997-08-21 | 2010-08-25 | ダイキン工業株式会社 | Method for producing pentafluoroethane |
| WO2012105700A1 (en) * | 2011-02-04 | 2012-08-09 | 旭硝子株式会社 | Method for purifying 2,3,3,3-tetrafluoropropene |
| JPWO2012105700A1 (en) * | 2011-02-04 | 2014-07-03 | 旭硝子株式会社 | Method for purifying 2,3,3,3-tetrafluoropropene |
| US9126885B2 (en) | 2011-02-04 | 2015-09-08 | Asahi Glass Company, Limited | Method for purifying 2,3,3,3-tetrafluoropropene |
| JP5971123B2 (en) * | 2011-02-04 | 2016-08-17 | 旭硝子株式会社 | Method for purifying 2,3,3,3-tetrafluoropropene |
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