Method for conditioning carboxylate/sulfonate composite membranes for producing KOH

摘要

A procedure for conditioning new composite laminated membranes in chlor-alkali cells producing KOH, said membrane being comprised of a laminated composite made from individual perfluorosulfonyl and perfluorocarboxylic acid layers, so that said membrane will not delaminate during startup operation of the cell. The procedure comprises charging the cathode compartment of the cell with a KOH solution of less than about 27 percent by weight KOH before startup and gradually raising the KOH concentration during the first 12 to about 20 hours of operation to about 30 percent after which the cell can be operated at higher KOH concentrations which provide better current efficiencies.