GB496348A - Manufacture of tetrachlorethylene - Google Patents

Abstract

Tetrachlorethylene is produced by passing over a hot inorganic catalyst a mixture of acetylene, ethylene, or a chlorhydrocarbon having 2 carbon atoms and not more than 4 chlorine atoms, and hexachlorethane or a fully chlorinated paraffin containing more chlorine than hexachlorethane such as fully chlorinated propane or butane. A suitable mixture may be made by treating tetrachlorethylene with chlorine to convert a part of it into hexachlorethane, and then passing this mixture together with acetylene, ethylene or the chlorhydrocarbon containing not more than 4 carbon atoms over the catalyst. The reaction temperature may be 200-400 DEG C., and the catalyst may be broken glass or porcelain, wood charcoal, bone charcoal, active carbon or silica gel. The catalyst may be impregnated with a substance known to promote splitting off of hydrogen chloride such as cupric chloride. Examples describe the production of tetrachlorethylene from mixtures of hexachlorethane with trichlorethylene, tetrachlorethane, and dichlorethylene, respectively and also from a chlorination product of tetrachlorethylene together with acetylene. In the last case, if excess of acetylene is used some di- and tri-chlorethylene are also produced.