Patent ID: 7658835
Filing Date: 2010-02-09
Classification: B01D,C25B

Abstract:
1. A method for electrolysis of an aqueous solution of hydrogen chloride and/or alkali metal chloride in an electrolysis cell, said cell comprising an anode half-element and an anode, a cathode half-element and a gas diffusion electrode as a cathode, a cation exchange membrane for separating the anode half-element and the cathode half-element, said method comprising: supplying a gas comprising oxygen to the cathode half-element, subjecting said aqueous solution to electrolysis in said cell, discharging excess gas containing oxygen and hydrogen from the cathode half-element, subjecting said excess gas containing oxygen and hydrogen, after said excess gas has been discharged from the cathode half-element, to catalytic oxidation of said hydrogen to reduce the level of hydrogen in said excess gas thereby forming reduced hydrogen excess gas, and supplying said reduced hydrogen excess gas to the cathode half-element.