METHOD OF PROCESSING A REACTION GAS MIXTURE OBTAINED WHEN BROM INATING DIFLUOROMONOCHLOROMETHANE AND OF RECOVERING DIFLUORO CHLOROBROMOMETHANE IN SUBSTANTIALLY PURE FORM

摘要

1321462 Bromine KALI-CHEMIE AG 18 Sept 1970 [20 Sept 1969] 44702/70 Heading C1A [Also in Division C2] Bromine is recovered from the gas mixture obtained in the bromination of difluorochloromethane by (a) optional conversion of difluorodibromo-methane into difluorochlorobromomethane and/or of hydrogen bromide into bromine by chlorination, (b) cooling to at least 100‹ C., (c) fractional condensation at 0À8 to 2 kg./cm.SP2/SP by introduction into the bottom of a stripping column operated under reflux, the temperature of the column being 10 to 80‹ C. at the bottom and 10‹ to 40‹ C. at the head, and the volume of reflux being adjusted by maintenance of a constant desired proportion by weight of difluorochlorobromomethane to difluorodibromomethane, and (d) recovering bromine from the bottom of the column. Any hydrogen bromide not converted to bromine in step (a) leaves the head of the stripping column and is absorbed in scrubbing towers, and may then be converted to bromine.