GB864165A - Hydrocarbon chlorination process - Google Patents

Abstract

A process for chlorinating a hydrocarbon mixture comprising a major proportion of a soft paraffin wax and a minor proportion of a normally liquid paraffinic hydrocarbon oil is characterised by an initial stage of contacting the hydrocarbon mixture with a chlorine-containing gas, passing the resulting mixture at an elevated pressure through a reaction zone, passing the resulting product mixture to a disengaging zone operated at an elevated pressure but at a pressure lower than in the reaction zone, wherein by-product hydrogen chloride and unreacted chlorine gases are separated from the chlorinated hydrocarbon mixture separately recovering the gases and the chlorinated hydrocarbon mixture and continuously passing the latter back to the reaction zone, along with additional chlorine-containing gas, continuing the sequential operations of reaction, disengaging and recycling, withdrawing at least a portion of the chlorinated hydrocarbon mixture from this stage of the process, passing the withdrawn chlorinated hydrocarbon mixture to at least one other succeeding stage containing a separate reaction zone and disengaging zone, the reaction zone having a pressure greater than the pressure in the reaction zone of the preceding stage and the disengaging zone having a pressure no less than the pressure in the reaction zone of the preceding stage, continuing the sequential operations of reaction, disengaging and recycling in the succeeding stage while passing chlorinated hydrocarbon recovered from the preceding stage and chlorine-containing gas into said stage, passing the chlorine and hydrogen chloride gases recovered from the disengaging zone to the reaction zone of the preceding stage, and recovering from the succeeding stage a chlorinated hydrocarbon mixture having a higher chlorine content than the chlorinated hydrocarbon mixture withdrawn from the preceding stage. Preferably at least three stages are used. Preferred hydrocarbon mixtures contain 55-80% of the wax and 20-45% of the oil; a minor proportion of a solvent may be present, e.g. a mixture of highly branched chain saturated hydrocarbons containing at least eleven carbon atoms. The temperature in each stage is preferably 50-140 DEG C.; actinic light may be used. The product chlorinated wax may be blown with air or nitrogen, and may be stabilized by the incorporation of e.g. glycols, polymers of epoxy-alkyl alkenyl ethers, tin hydrocarbons and iron salts. Specification 864,166 is referred to.