PROCESS FOR PREPARING DIFLUOROMETHANE (VARIANTS) Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: claimed process uses difluoromethane as cooling agent, solvent and spraying agent and comprises (a) contacting dichloromethane with hydrogen fluoride in the presence of fluorination catalyst to form stream containing difluoromethane, monochloromonofluoromethane and unreacted initial materials and (b) isolating difluoromethane from stream of products from stage (a) which uses sufficient amount of hydrogen chloride and in stage (b), fluorine hydrogen to monochloromonofluoromethane molar ratio being at least about 100:1. EFFECT: smaller amount of monochloromonofluoromethane by-product formed during the claimed process. 11 cl, 7 ex, 3 tbl