Korea Institute of Energy Research,
Keywords: co-electrolysis, solid oxide co-electrolysis cells , EIS analysis, gas chromatography
Summary:Using electricity from wind and solar sources, high-temperature solid oxide co-electrolysis cells (SOCs) can perform advantageous conversion of H2O/CO2 to high value syngas that can be used to produce electricity or synthetic hydrocarbons. In this work, the performance characteristics of flat-tubular solid oxide co-electrolysis cells are reported for production of syngas by electrochemical conversion of H2O/CO2. Anode-supported flat-tubular solid-oxide electrolysis cells were fabricated and tested at various operating temperatures and under various combinations of inlet-gas conditions. We also fabricated different electrolyte type SOC cells involving yttria-stabilized zirconia (YSZ) and scandium-stabilized ScSZ to improve the syngas yield. The electrochemical performance was analyzed using I-V curves, EIS analysis, and gas chromatography. Consequently, we confirm the correlation between the operating conditions and the electrochemical performance of the co-electrolysis process in the flat-tubular SOCs. Furthermore, it was found that the syngas yield of the ScSZ electrolyte-based SOC cell was better than that of the YSZ electrolyte-based SOC. The results show that using a flat-tubular SOC offered a high-efficiency conversion of H2O/CO2, with high yield and good-quality syngas.