PROCESS FOR PRODUCING DIFLUOROMETHANE

摘要

Difluoromethane is prepared by reacting dichloromethane and hydrogen fluoride in a liquid phase in the presence of a fluorination catalyst under reaction conditions in which the reaction pressure is between 1 and 10 kg/cm<2>ab., and the reaction temperature is between 50 and 150 DEG C, provided that the selected reaction temperature is higher than a temperature at which hydrogen fluoride is not liquefied under the selected reaction pressure. Under the above conditions, the conversions of dichloromethane and HF are very high, and amounts of by-products other than R30 are very low, typically less than 0.1 % per difluoromethane, when the unreacted materials are recycled. A material of a reactor is hardly corroded by the reaction using an antimony chlorofluoride and HF which are highly corrosive, as long as the above conditions are maintained.