Process for the preparation of hexafluoropropene

摘要

A process is described for the preparation of hexafluoropropene by thermal cleavage of chlorotetrafluoroethane and perfluorocyclobutane at 600 to 1000@C under pressure of 1 to 1000 kPa. The thermal cleavage reaction is carried out in the presence of at least 0.05 mol of tetrafluoroethene per mol of chlorotetrafluoroethane and perfluorocyclobutane. This allows hexafluoropropene to be obtained with relatively little additional equipment but in good selectivity and with an improved space-time yield; an azeotropic mixture of chlorotetrafluoroethane and perfluorocyclobutane, which is obtained during work-out of the products of chlorodifluoromethane pyrolysis, can be used in an advantageous manner.