PROCESS FOR THE SEPARATION OF CIS- AND TRANS-1,2- DICHLOROETHYLENE FROM 1,1-DICHLOROETHANE BY DISTILLATION AND ISOMERIZATION

摘要

1503987 1,1,1-Trichloro ethane DOW CHEMICAL CO 18 April 1975 [22 April 1974 (3)] 16152/75 Heading C2C 1,1,1-Trichloroethane is produced by (a) reacting ethylene and hydrogen chloride, wherein the hydrogen chloride is obtained from another step in the process, in the presence of aluminium chloride catalyst to produce ethyl chloride; (b) reacting said ethyl chloride and recycled ethyl chloride and 1,1-dichloroethane with chlorine at a temperature of 400‹ to 550‹ C.; (c) subjecting the reaction mixture from (b) to a liquid quench, thus producing (1) a gaseous product mixture comprising hydrogen chloride, vinyl chloride, and vinylidene chloride, and (2) liquid product; (d) returning a minor portion of said liquid product to the quench zone, and either (A) mixing the remaining portion of said liquid product with or without separating 1,1-dichloroethane therefrom with the gaseous product mixture formed in (c) (1), or (B) dehydrochlorinating the remaining portion of said liquid product thus converting the major portion of the 1,1,1-trichloroethane to vinylidene chloride and mixing the vinylidene chloride so formed with the gaseous product mixture formed in (C) (1); and hydrochlorinating the mixture in (A) or (B) to form a second product mixture comprising hydrogen chloride, ethylene, ethyl chloride, vinyl chloride, vinylidene chloride, 1,1-dichloroethane, cis- and trans - 1,2 - dichloroethylenes, 1,1,1, - trichloroethane, ethylene dichloride, trichloroethylene, 1,1,2-trichloroethane and unsymmetrical tetrachloroethane; (e) separating the hydrogen chloride, ethylene, ethyl chloride, vinyl chloride, and vinylidene chloride from said second product mixture; (f) separating from the remaining portion of said second product mixture 1,1-dichloroethane and the cis- and trans-1,2- dichloroethylenes; (g) separating 1,1,1-trichloroethane from the portion remaining after the separation in (f).