Patent ID: 6080298
Filing Date: 2000-06-27
Classification: C25B

Abstract:
In a method comprising conducting electrolysis of an aqueous solution of sodium chloride with an electrolysis cell comprising an anode an oxygen-reduction cathode, and a cation-exchange membrane which divides the cell into an anode compartment containing an anolyte of an aqueous solution of sodium chloride and a cathode compartment in which said cathode is placed directly against the cation-exchange membrane, said cathode compartment being supplied with a humidified gas containing oxygen, the improvement wherein said anolyte containing an aqueous solution of sodium chloride is provided with a concentration by weight of sodium chloride of less than 200 g/l, and the water humidifying the gas containing oxygen is provided sole in the form of water vapour, and maintaining reaction conditions so as to obtain a concentration by weight of sodium hydroxide between the cation-exchange membrane and the cathode of less than 38.8%.