(Invited) High Temperature Steam/CO2 Co-electrolysis Using Solid Oxide Electrolyser Stack at Shanghai Institute of Applied Physics

Abstract

The high temperature steam/CO2 co-electrolysis using solid oxide electrolyser cell technology is considered to be an important alternative for syngas production with carbon-free process. Previously, the co-electrolysis of steam and CO2 in single cell have been published in Faraday Discussions by our team, and electrolysis parameters have been investigated and optimized systematically. In this paper, we carried out the steam/CO2 coelectrolysis experiment using a 30-cell SOC stack composed of NiO-YSZ/YSZ/GDC/LSCF-GDC with the single cell effective area of 63cm2 (developed by Ningbo SOFCMAN Energy Technology Co., Ltd). The electrochemical performance of stack was investigated through OCV, I-V and long-term stability tests. From OCV and I-V curves, we can see the electrochemical performance of steam/CO2 co-electrolysis is slightly worse than that of steam electrolysis. And stability test was carried out in galvanostatic electrolysis mode (750 oC, 0.25 A/cm2, H2/H2O/CO2= 20/53.33/26.67(molar ratio); H2: 1.645NL/min) for 100hrs, the product of hydrogen electrode was analysis though rotameter and Agilent gas chromatograph 7820 , and the steam and CO2 utilization can be calculated to be 55.38% and 46.33%, respectively. Figure 1