PROBLEM TO BE SOLVED: To provide a method for purifying pentafluoroethane, enabling to obtain the compound having a high purity and used for industies without by- producing trifluoroethane difficult in separation by thermally treating crude pentafluorothane containing chloropentafluoroethane in the presence of hydrogen under specific conditions. ;SOLUTION: This method for purifying pentafluoroethane comprises thermally treating the crude pentafluoroethane (F125) containing chloropentaluoroethane (F115) in the presence of hydrogen at a temperature of ≥550°C, preferably 600-700°C, in a H2/F115 molar ratio of at least 10, preferably 80-1000. The pressure is preferably the atmospheric pressure or a pressure up to 20 bar. A reaction vessel made from hastelloy, etc., is industrially preferable. The retention time of the reaction mixture is preferably 1-100sec. The flow of the reactant (crude F125 and H2) charged into the reaction vessel may be diluted with an inert gas such as helium gas.;COPYRIGHT: (C)1998,JPO
展开▼
