Chlorine recovery

Claim 1

A CONTINUOUS PROCESS FOR RECOVERY OF FREE CHLORINE FROM A CHLORINE-CONTAINING GAS STREAM WHICH COMPRISES (1) PASSING SAID CHLORINE-CONTAINING GAS STREAM THROUGH A PRELIMINARY ADSORPTION ZONE CONTAINING SILICA GEL TO A REMOVE THEREFROM CONTAMINANTS WHICH ARE MORE ADSORBABLE THAN CHLORINE; (2) ON AN ADSORPTION CYCLE: PASSING SAID PRELIMINARILY-TREATED GAS STREAM THROUGH AN ADSORPTION ZONE CONTAINING SILICA GEL, SAID SILICA GEL BEING AT A TEMPERATURE LOWER THAN THAT OF THE ENTERING GAS STREAM, RECOVERING A PARTIALLY CHLORINE-STRIPPED GAS STREAM FROM SAID ADSORPTION ZONE, SEPARATIVELY COOLING AT LEAST A PORTION OF SAID PARTIALLY STRIPPED GAS STREAM, PASSING SAID COOLED PARTIALLY STRIPPED GAS STREAM TO AT LEAST ONE OTHER ADSORPTION ZONE CONTAINING SILICA GEL, RECOVERING THEREFROM A SUBSTANTIALLY CHLORIDE-FREE GAS STREAM; (3) ON A REGENERATION CYCLE: MAINTAINING AN ADSORPTION ZONE CONTAINING SILICA GEL HAVING CHLORINE ADSORBED THEREON AND AT LEAST ONE OTHER ADSORPTION ZONE CONTAINING SILICA GEL HAVING CHLORINE ADSORBEB THEREON, SUBJECTING SAID ADSORPTION ZONES ON THE REGENERATION CYCLE TO REDUCED PRESSURE-THEREBY DESORDING SAID ADSORDED CHLORINE, RECOVERING SAID DESORBED CHLORINE, THEREAFTER PASSING AT LEAST A PORTION OF SAID PREVIOUSLY RECOVERED CHOIRINE-FREE GAS STREAM FROM THE ADSORPTION CYCLE THROUGH SAID OTHER ADSORPTION ZONE ON THE REGENERATION CYCLE TO STRIP THE FINAL TRACES OF ADSORBEB CHLORINE THEREFROM; AND (4) AT INTERVALS REVERSING THE ADSORPTION AND REGENERATION CYCLES.