Efficiency and fuel utilization of methane-powered single-chamber solid oxide fuel cells

Abstract

The single-chamber solid oxide fuel cell (SC-SOFC) is a simplification of the conventional dual-chamber SOFC and has great potential for meeting portable power generation needs. While the high energy density of hydrocarbon fuels makes SC-SOFC a promising candidate as a power source for scenarios where portability is most preferred, the low efficiency and fuel utilization reported by many experimental groups have presented a major barrier keeping it from real application. Based on an experimentally validated numerical model, this work systematically investigates the fuel cell efficiency and fuel utilization of a methane-powered SC-SOFC as a function of operating parameters including flow rate, fuel-to-oxygen ratio, fuel cell layout and balance gas. We predict that the maximum achievable efficiency of a single-cell SC-SOFC is above 10% and the efficiency at typical operating conditions is above 5%, significantly higher than the reported 1% in literature. Optimization approaches are proposed at different levels in terms of both improving the power output and reducing the unspent fuel.