Testing aqueous caustic electrolyzers at high temperatures

Abstract

Increasing the electrochemical cell operating temperature allows a general improvement of the operating energetics of hydrogen production via alkaline solution water electrolysis. Considerations of operation of these advanced cells above 100°C leads to a reexamination of all of the basic materials stabilities. One previous controversy has been with respect to the upper temperature value for a stable asbestos electrochemical cell separator. In addition to testing alternative materials for the cell separator, one must examine which of the structural polymers can be used as a cell frame, reexamine the stability of the selected anode electrocatalyst and finally, determine if the plumbing and piping selected will introduce corrosion products which could affect the cathode electrocatalyst. This paper describes the work performed at Teledyne Energy Systems on the studies of alkaline electrolyzers and materials for operation at temperatures up to 150°C. This program, under contract to the Brookhaven National Laboratory, has proceeded through the design and construction of an applied research sized test system. The materials testing and preliminary test results obtained with the system are described.