Patent ID: 9181624
Filing Date: 2015-11-10
Classification: C25B

Abstract:
1. A method of electrolyzing brine using a two-chamber ion exchange membrane electrolytic cell divided, by an ion exchange membrane, into an anode chamber equipped with an anode and a cathode gas chamber equipped with a gas diffusion electrode, the method comprising: supplying an oxygen-containing gas to the cathode gas chamber through an oxygen-containing gas inlet, and a sealing pot or a valve downstream of an outlet of the cathode gas chamber for a caustic soda aqueous solution and the oxygen-containing gas; and reducing a differential pressure from a non-pressurized state by pressurizing an inside of the cathode gas chamber by changing a liquid height of the sealing pot or an opening degree of the valve, the differential pressure being a difference between a liquid pressure in the anode chamber and a gas pressure in the cathode gas chamber, thereby decreasing a salt concentration in the caustic soda aqueous solution that is electrolytically produced, wherein the differential pressure is reduced to 2.4 kPa or less by pressurizing the inside of the cathode gas chamber.