GB894137A - Process for the production of chlorinated hydrocarbons - Google Patents

Abstract

Metal halide catalysts for chlorination processes (see Group IV(b)) comprise halides of metals of variable valency, e.g. Cu, Cr and Fe, alone or in combination with other metals such as Na or K. The catalysts are preferably used as chlorides impregnated on an inert material such as silica gel, alumina, kieselguhr and pumice. The catalyst particles may be diluted with similar but non-impregnated particles (see Specification 894,138. Specifications 853,754 and 884,622 also are referred to.ALSO:Chlorinated hydrocarbons are prepared by the gas phase reaction between an aliphatic C1-4 hydrocarbon and/or a partially chlorinated derivative thereof, and a chlorinating agent which is hydrogen chloride and/or chlorine and an oxygen-containing gas, in the presence of metal halide catalyst particles in a tubular reactor of internal diameter 1/2 inch-4 inches, the catalyst particles each having a longest dimension of not more than 2 inches and each having a total volume equal to that of a sphere of diameter one-fifth to one-seventh of the internal diameter of the tubular reactor, the residence time of the reactants in the catalyst zone being between 0.2 and 10 seconds. The oxygen-containing gas may be oxygen alone, air, oxygen enriched air, air and an inert gas, or air, oxygen and an inert gas. The metal halide catalyst is preferably derived from a metal of variable valency, such as Cu, Cr and Fe; other metal halides, e.g. of Na and K, may be present. The catalyst may be impregnated on an inert carrier, and the catalyst particles may be mixed with 1-3 times their volume of inactive particles. The preferred reaction temperature is 325 DEG C-700 DEG C. Heat may be removed from the reactor by means of a heat exchange system, e.g. a molten mixture of KNO3, NaNO3 and NaNO2. Non-chlorinated and partially chlorinated reaction products may be recycled. In examples, CH2Cl, CH2Cl2, CHCl3 and CCl4 are prepared from methane. Specifications 853,754, 884,622 and 894,138 are referred to.