DIFLUOROCHLOROMETHANE PRODUCTION PROCESS Russian patent published in 2002 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: difluorochloromethane, refrigerant component, is prepared by hydrofluorination of chloroform by anhydrous hydrogen fluoride in presence of antimony pentachloride at elevated temperature and pressure followed by separation of reaction gases by two-step rectification at elevated pressure. First-step rectification is carried out to run off 5-50% of formed difluorochloromethane into light fraction. Picked fraction is washed, dried, and rectified to yield desired product. Rectification of reaction gases in the second step is carried out in presence of chloroform and antimony pentachloride to run off the rest of the product into light fraction, which is further used for production of tetrafluoroethylene. EFFECT: reduced power consumption, metal intensity of equipment, and amount of acidic effluent owing to rational distribution of process streams. 5 cl, 2 tbl, 4 ex