High-performance gaseelectricity cogeneration using a direct carbon solid oxide fuel cell fueled by biochar derived from camellia oleifera shells

Direct carbon solid oxide fuel cells (DC-SOFCs) are promising for generating electricity cleanly and efficiently from solid carbon fuel. Biochar from Camellia oleifera shells is used in a tubular electrolyte-supported 2-cell DC-SOFC stack with a yttrium-stabilized zirconia (YSZ) electrolyte and silver-gadolinium-doped ceria (Ag-GDC) as symmetrical electrodes. The DC-SOFC exhibits comparable electrical performance to the same cell operated on hydrogen fuel and can cogenerate CO and electricity when fueled by biochar. The gas-electricity cogeneration performance of the DC-SOFC is tested under constant-current discharge in terms of electrical power output, CO output rate and purity, electrical conversion efficiency, and gas-electrical cogeneration conversion efficiency. The purity of the output CO can reach more than 80%. Considering the chemical energy of CO a part of the output power, the energy conversion efficiency of >70% is attained. Furthermore, the gas eelectricity cogeneration performance is relatively stable before the biochar fuel is exhausted. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.