ELECTROLYSIS OF ALKALI METAL HALIDE BRINES USING OXYGEN CATHODE SYSTEMS

摘要

A process for the electrolysis of an alkali metal halide brine in an electrolytic cell having an anode compartment having at least one anode, a cathode compartment having at least one cathode, and a membrane in contact with the cathode (thereby forming a membrane electrode assembly) which separates the anode compartment from the cathode compartment. The method comprises (a) feeding the alkali metal halide brine to the anode compartment; (b) electrolyzing the alkali halide brine to produce a halogen gas and alkali metal ions; (c) passing the alkali metal ions and water through the membrane into the cathode compartment; and (d) feeding an oxygen-containing gas to the cathode compartment so that the oxygen is reduced at the cathode and a concentrated alkali metal hydroxide solution is produced. The process is further characterized by having a flow field located adjacent to the cathode to facilitate transporting the oxygen gas to the cathode and alkali metal hydroxide away from the cathode and in that the flow field comprises an electronically conductive material having a porosity of at least 30 percent and a mean pore size of at least 10 microns.