METHOD OF 1,1-DIFLUOROETHANE REFINING Russian patent published in 1997 - IPC

FIELD: chemical industry. SUBSTANCE: method involves treatment of 1,1-difluoroethane with fluorinating agent - fluorine or its mixture with inert gas - by contact of gaseous fluorinating agent with liquid phase making by directly with 1,1-difluoroethane or its solution in solvent that is inert to fluorine effect. Mole ratio of feeding fluorine to vinyl chloride = 1.2-5. Halogencarbon no containing hydrogen, for example, 1,1,2-trifluorotrichloroethane (coolant-113), perfluorodecaline, perfluoromethylcyclohexane, perfluorodimethylcyclohexane were used as a solvent. Treatment can be carried out in column type reactor by addition of fluorine at some points by height or by some steps. Product can be subjected for additional refining with adsorbent - synthetic zeolite of type NaA or Na-mordenite. Additional refining is carried out in the gaseous phase at loading 20-50 l/h per 1 l adsorbent. Method can be used for vinyl chloride impurity removal from 1,1-difluoroethane (coolant-152a). EFFECT: improved method of refining. 12 cl, 4 tbl