| 摘要 |
A process is disclosed for making CF3CF═CHF or mixtures thereof with CF2═CFCHF2. The process involves (i) contacting CHCl2CF2CF3, and optionally CHClFCF2CClF2, in a reaction zone in the presence of a catalytically effective amount of dehydrofluorination catalyst to produce CCl2═CFCF3, and, if CHClFCF2CClF2 is present, CClF═CFCClF2; (ii) contacting CCl2═CFCF3 and CClF═CFCClF2, if any, formed in (i) with hydrogen fluoride (HF) in a reaction zone, optionally in the presence of a fluorination catalyst, to produce CClF═CFCF3, and if CClF═CFCClF2 is present, CF2═CFCClF2; (iii) contacting CClF═CFCF3 and CF2═CFCClF2, if any, formed in (ii) in a reaction zone with H2 in the presence of a catalyst comprising a catalytically effective amount of palladium supported on a support of chromium oxide, fluorinated chromium oxide, chromium fluoride, aluminum oxide, aluminum fluoride, and/or fluorinated alumina to produce a product mixture comprising CF3CF═CHF, and if CF2═CFCClF2 is present, CF2═CFCHF2; and (iv) recovering CF3CF═CHF, or a mixture thereof with CF2═CFCHF2, from the product mixture formed in (iii); and optionally (v) separating at least a portion of any CF3CF═CHF in the product mixture formed in (iii) from the CF2═CFCHF2 in the product mixture formed in (iii). Also disclosed are azeotropic compositions involving CCl2═CFCF3 and HF; involving CCl2═CFCF3, CClF═CFCClF2 and HF; involving CClF═CFCF3 and HF; involving CClF═CFCF3, CF2═CFCClF2 and HF; or involving CF2═CFCHF2 and HF.
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