GB821128A - Decontamination of chlorinated alkanes - Google Patents

Abstract

A process of decontaminating the gaseous reaction product from a thermal alkane chlorination process contaminated with finely-divided carbon and/or water, comprises the steps of intimately contacting the gaseous product with liquid concentrated sulphuric acid or oil by simultaneously passing the gaseous product and sulphuric acid or oil through a first contactng zone and then through a following zone having a restricted cross-sectional area such that the fluid is thereby subjected to a pressure reduction of at least 1.8 p.s.i., the sulphuric acid, if used, being at least 90% concentration and the oil, if used, being a high-boiling hydrocarbon oil having a viscosity of not greater than 20 centipoises. The oil should have a boiling-point above about 300 DEG F. Highly saturated paraffin oils are preferred but small quantities of unsaturated impurities may be present. Pure paraffins, e.g. containing 10-16 carbon atoms, may be employed. The products produced by a process employing a fluidized bed may be treated by the process. Examples relating to the treatment of a gaseous mixture containing ethane, hydrogen chloride, ethyl chloride, ethylene dichlorides, water and carbon, with sulphuric acid and of a similar mixture containing carbon, with hydrocarbon oil, are furnished. Representative of other products mentioned which may be treated are methyl chloride, propylene dichloride and octyl chlorides. An apparatus for carrying out the process is described.