Patent ID: 6166275
Filing Date: 2000-12-26
Classification: C07C,Y02P

Abstract:
A process comprising the steps of:(a) reacting reactants comprising methylene chloride and hydrogen fluoride in the presence of an effective amount of a fluorination catalyst and in a reactor made of a fluorinated polymer to produce a reaction product; and(b) distilling the reaction product in a first distillation column to produce a first column bottoms product that is recycled to the reactor and a first column overhead product comprising hydrogen chloride, difluoromethane, monochloromonofluoromethane, methylene chloride, and hydrogen fluoride;(c) distilling the first column overhead product in a second distillation column to produce a second column bottoms product comprising monochloromonofluoromethane, methylene chloride, and hydrogen fluoride and a second column overhead product comprising difluoromethane and hydrogen chloride;(d) vaporizing and superheating the second column bottoms product; and(e) recycling the vaporized and superheated second column bottoms product to the reactor.