Hydrogen chloride is a gas-phase by-product of many manufacturing chlorination processes. Growing environmental
concerns have prompted several techniques for converting hydrogen chloride to elemental chlorine for recycling. A
novel electrochemical membrane process has been developed for the recovery of chlorine from gaseous hydrogen
chloride waste. Hydrogen chloride is reduced at the cell cathode, producing hydrogen gas and chloride ions. The
chloride ions migrate across the molten salt electrolyte-saturated membrane to the anode where chlorine is evolved
by oxidation. Experiments began with free electrolyte trials in the absence of a membrane separator and were
followed by a single membrane cell study. Preliminary studies show that electrochemical membrane separation is a
feasible alternative for the removal of chlorine from hydrogen chloride. The results indicate that chlorine can be
effectively removed from a hydrogen chloride gas mixture at reasonable voltages, resulting in a high conversion
efficiency. The proposed system offers advantages over conventional means such as on-site chlorine recycling in a
single-step and on a continuous basis. © 1999 Elsevier Science B.V.