Electrolysis of alkali metal halides in a three compartment cell with self-pressurized buffer compartment

摘要: The invention describes a pressurized, three compartment membrane cell for the electrolyzing aqueous alkali metal halides at low voltages and with high cathodic current efficiencies. Unitary electrode-electrolyte structures, in form electrochemically active electrodes physically bonded to ion transporting permselective membranes divide into anode, cathode buffer compartments. feed is pressurized maintain positive pressure differential respect anode feeds. flexible unitary electrode-membrane electrolytes are forced outwardly against electronically conductive collectors provide uniform, constant controllable contact between thereby minimizing ohmic losses. A operated this fashion not only minimizes voltage required electrolyze halide solution, but also increases efficiency caustic concentrations by providing multiple hydroxide rejection stages single process. improvement realized forming lower concentration than reducing backmigration of OH- ions compartment.