Method for reducing formation of polychlorinated aromatic compounds during oxychlorination of C1-C3 hydrocarbons

摘要

An improved process is disclosed for manufacturing chlorinated hydrocarbon by way of oxychlorination which yields reduced levels of environmental toxins such as, chlorobenzenes, polychlorinated biphenyls, polychlorinated dibenzodioxins and polychlorinated dibenzofurans. The process involves fixed bed or fluid bed catalyzed oxychlorination of a hydrocarbon reactant containing from 1 to 3 carbon atoms. The oxychlorination process consists of contacting the hydrocarbon reactant with oxygen or oxygenated gas and at least a portion of externally obtained hydrogen chloride in the presence of the oxychlorination catalyst in a heated reaction zone operated at from 150 DEG C to 600 DEG C and recovering chlorinated hydrocarbon from the effluents of the reaction zone. The improvement consists of the use of at least a portion of the hydrogen chloride from an external source other than from recovery of hydrogen chloride from the thermal pyrolysis of the product from the operated oxychlorination process, wherein the external hydrogen chloride, containing aromatic hydrocarbons, is pretreated before use in the operated oxychlorination process by a means for removal of the aromatic hydrocarbons.