Abstract:
1,129,637. Purification of phosgene. ALLIED CHEMICAL CORP. 21 April, 1966 [23 April, 1965], No. 17570/66. Heading C1A. Chlorine is separated from phosgene containing more than 25 p.p.m. of chlorine by contacting the liquid phosgene with activated carbon and separating the purified carbon. This contact is preferably conducted in the temperature range from- 10‹ to + 8‹ C. Preferably the contact of liquid phosgene with activated carbon is terminated before the carbon has absorbed 16% of its weight of chlorine. The absorbed chlorine is converted into phosgene by passing carbon monoxide over the activated carbon containing chlorine at above 70‹ C. This is continued until the gas leaving the activated carbon contains less than 0À05% by weight of phosgene.