PRODUCTION OF 1,1,1-TRICHLOROETHANE

1281541 Chlorination process IMPERIAL CHEMICAL INDUSTRIES Ltd 8 Jan 1970 [23 Jan 1969] 3943/69 Heading C2C 1,1,1 - Trichloroethane is produced by continuously introducing 1,1 -dichloroethane and chlorine into a tubular reactor closed at one end, thereby producing a turbulent reaction zone at the closed end. The hot reaction gases entrain fuse feed into the turbulent zone. Reactants are suitably introduced through a conduit or conduits extending downwardly towards the closed end of the reactor. These may take the form of the vertical arm of a T-piece or an exit jet from the bottom of a U-tube, the reagents being introduced separately into the other arms. Temperatures of 300-450‹ C. and contact times of at least 5 seconds are specified. Vinyl chloride and vinylidene chloride are produced as by-products, and the process may be part of an integrated cycle in which the reaction product of the chlorinator is fractionally distilled to give a heavy fraction of 1,1,1-trichloroethane and a light fraction of vinyl chloride and vinylidene chloride, the light fraction and a vinyl chloride feedstock are hydrochlorinated in a Friedel-Crafts-catalysed liquid-phase reaction to give 1,1-dichloroethane and 1,1,1-trichloroethane, and the 1,1-dichloroethane is recycled to the chlorinator. Hydrochlorination is preferably effected using a ferric chloride catalyst in nitrobenzene. Hydrochlorination temperatures of 20‹ to 70‹ C. are specified. Chlorination and hydrochlorination may be effected under atmospheric or superatmospheric pressure. Other chlorination by-products are 1,2-dichloroethylene and 1,1,2-trichloroethane.