| 摘要 |
PCT No. PCT/JP95/01488 Sec. 371 Date Jan. 28, 1997 Sec. 102(e) Date Jan. 28, 1997 PCT Filed Jul. 25, 1995 PCT Pub. No. WO96/04226 PCT Pub. Date Feb. 15, 1996The purification of pentafluoroethane (HFC-125) which is composed of a process A, in which an unpurified mixture (1), containing at least chloropentafluoroethane (CFC-115) and pentafluoroethane (HFC-125) is reacted with hydrogen (4) in the presence of a catalyst in gas phase to reduce the said chloropentafluoroethane (CFC-115); and a process B, in which a reaction mixture produced by the preceding reaction is separated into a first mixture (3) composed mainly of hydrogen and a second mixture (2), composed mainly of pentafluoroethane (HFC-125). In this method, purification is performed by adding the said first mixture (3) to the said unpurified mixture (1) in a state that the hydrogen chloride is removed from the first mixture (3) in process B until the level of hydrogen chloride drops to 0.5 or less than that of CFC-115 in the unpurified mixture (1) in the molar ratio, or hydrogen chloride is removed from the said reaction mixture until, when mixed with the unpurified mixture (1), the level of hydrogen chloride drops to 0.5 or less than that of CFC-115 in the mixture in the molar ratio. Thus, CFC-115 can be exterminated (or removed) cheaply and efficiently without decreasing it's reactivity (or activity) and a high yield of HFC-125 can be obtained.
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