CONTROL OF OXYCHLORINATION REACTIONS

Chlorinated hydrocarbons are prepared by reacting (a) aliphatic C1 to C4 hydrocarbons and/or their incompletely chlorinated derivatives, (b) an oxygen-containing gas, and (c) chlorine and/or hydrogen chloride in a fluidized bed of metal halide oxychlorination catalyst particles, the velocity of the product gas emerging from the fluidized bed being reduced in a vapour zone above the bed, subsequently increasing the velocity above that at which the gases are removed from the bed and imparting a circular motion thereto to thereby deposit entrapped fines in the zone of increased velocity and removing the gas substantially free from fines from said zone whilst maintaining said zone at a temperature above the dew point of the gas. The increase in gas velocity may be effected by introducing the gas into a restricted orifice or inlet of a dust collector or cyclone and so increasing the velocity by the Venturi effect. Preferred catalysts are copper chloride-potassium chloride and copper chloride-zinc chloride-calcium chloride catalysts.