MANUFACTURE OF 1,1,1-TRICHLOROETHANE

1,273,989. Methyl chloroform. IMPERIAL CHEMICAL INDUSTRIES Ltd. 17 Sept., 1969 [9 Oct., 1968 (2)], Nos. 47796/68 and 47797/68. Heading C2C. Methyl chloroform is prepared by (a) thermally chlorinating ethyl chloride or a mixture thereof with 1,1-diohloroethane, (b) fractionally separating from the product of (a) a light fraction comprising ethylene, vinyl chloride, vinylidene chloride and hydrogen chloride and a heavy fraction comprising methyl chloroform and other chlorinated ethanes, (c) hydrochlorinating, in the same or different reactors, ethylene and the said light fraction and withdrawing a reaction product comprising ethyl chloride, 1,1-dichloroethane and methyl chloroform, (d) fractionally separating methyl chloroform from the said heavy fraction, and (e) fractionally separating methyl chloroform from the reaction product of step (c) above and returning the residual ethyl chloride and 1,1-dichloroethane to the chlorination zone in step (a) above. Chlorination is preferably effected in an empty reactor at 375-175‹ C. using a ratio of chlorine: organic feed of 0À5 : 1 to 1À5 : 1 and contact times of at least 5 seconds. Fluidized beds may also be used. Vinylidene chloride may be tapped off. Hydrochlorination may be effected in a non- aqueous liquid medium, for example nitrobenzene or a mixture of the product hydrocarbons, using a Friedel-Crafts catalyst, for example ferric chloride or aluminium chloride, at 20 to 70‹ C. The product may be freed from the catalyst by conventional means. Both chlorination and hydrochlorination may be effected at atmospheric or superatmospheric pressure. The overall process is preferably continuous.