Patent GB-1078065-A (GB)
Title: Hydrogen chloride separation
IPC: C01B7/01
Filed: 1964-09-30
Abstract: <FORM:1078065/C4-C5/1> A process for the separation of HCl from ethylene, both contained in a gaseous stream as from the thermal cracking of chlorinated hydrocarbons, comprises passing the stream into a Venturi tube with a liquid inlet situated at the low pressure region thereof, passing an aqueous liquid into the Venturi by the pressure drop of the gaseous stream, passing the two phase dispersion into a vessel where the two phases separate, the gaseous phase containing ethylene being recovered, and HCl impurities being contained in the aqueous phase.  The liquid phase containing HCl may be recycled into the Venturi to provide the aqueous liquid. The aqueous liquid may be pure water or water containing small amounts of salts or acids, e.g. HCl, NaOH, KOH.  The preferred Venturi tube is composed of 2 opposed flaring nozzles separated by a narrow space (Fig. 2), the gaseous stream enters at 13 and the aqueous liquid at 15 and the two-phase liquid gas dispersion passes out of the Venturi through 14.  In a modification of the process the Venturi tube may be replaced by a conduit containing means such as an orifice plate or valve to reduce the cross-sectional area thereof and to provide therein a low-pressure zone at which the liquid inlet is situated.ALSO:<PICT:1078065/C1/1> A process for the separation of HCl from a water insoluble component, both contained in a gaseous stream, comprises passing the stream into a Venturi tube with a liquid inlet situated at the low pressure region thereof, passing an aqueous liquid into the Venturi by the pressure drop of the gaseous stream, passing the two phase dispersion into a vessel where the two phases separate, the gaseous phase is recovered, HCl impurities being contained in the aqueous phase.  The liquid phase containing HCl may be recycled into the Venturi to provide the aqueous liquid.  The water insoluble component may be a hydrocarbon or chlorinated hydrocarbon.  The aqueous liquid may be pure water containing small amounts of salts or acids, e.g. HCl, NaOH, KOH.  The preferred Venturi tube is composed of 2 opposed flaring nozzles separated by a narrow space (Fig. 2).  The gaseous stream enters at 13 and the aqueous liquid at 15 and the two phase liquid gas dispersion passes out of the Venturi through 14. In a modification of the process the Venturi tube may be replaced by a conduit containing means such as an orifice plate or valve to reduce the cross-sectional area thereof and to provide therein a low pressure zone at which the liquid inlet is situated.ALSO:<PICT:1078065/C2/1> A process for the separation of HCl from a water insoluble component, e.g. a chlorinated hydrocarbon both contained in a gaseous stream as from the substitutive chlorination of hydrocarbons or oxychlorination procedures, comprises passing the stream into a Venturi tube with a liquid inlet situated at the low pressure region thereof, passing an aqueous liquid into the Venturi by the pressure drop of the gaseous stream, passing the two-phase dispersion into a vessel where the two phases separate, the gaseous phase containing the chlorinated hydrocarbon is recovered, HCl impurities being contained in the aqueous phase. The gaseous stream may result from the substitutive chlorination of methane, ethane, propane or ethyl chloride or may contain ethylene dichloride and result from the oxychlorination reaction between ethylene, HCl and air.  The liquid phase containing HCl may be recycled into the Venturi to provide the aqueous liquid. The aqueous liquid may be pure water or water containing small amounts of salts or acids, e.g. HCl, NaOH, KOH.  The preferred Venturi tube is composed of two opposed flaring nozzles separated by a narrow space (Fig. 2), the gaseous stream enters at 13 and the aqueous liquid at 15 and the two-phase liquid gas dispersion passes out of the Venturi through 14. In a modification of the process the Venturi tube may be replaced by a conduit containing means such as an orifice plate or valve to reduce the cross-sectional area thereof and to provide therein a low pressure zone at which the liquid is situated.