Operation of High Temperature Steam Electrolyzer Module

A nominally 4-kW planar solid oxide stack module was operated in electrolysis mode. The module consisted of two 60-cell stacks with an integrated steam generator. The tests included both steam electrolysis to produce hydrogen and steam-carbon dioxide co-electrolysis to produce syngas. The initial performance of the module matched the performance of a 10-cell short stack. Fairly rapid initial degradation, attributed primarily to thermal imbalance from the heat duty of steam generator was noted. Reducing the heat duty of the steam generator within the thermal enclosure significantly improved the performance stability. The production of hydrogen and syngas was verified using dew point sensor and gas chromatograph.