Pressurized Solid Oxide Fuel Cells with Reformate as Fuel

Abstract

The influence of pressure on an SOFC was studied with steam-reformed methane as a fuel. Experiments were performed with a reformate containing 58.4% H2, 20% H2O, 12.2% CO, 5.5% CO2 and 3.9% CH4 and another mixture containing 18% H2, 34% H2O, 2% CO, 27% CO2 and 19% CH4 as well as a hydrogen/nitrogen mixture. The influence of pressure on OCV, power density at constant voltage and constant current as well as on gas composition was examined for the different fuels. Pressure dependency of OCV was found to be different for the reformate gases than for hydrogen. The pressure increase of OCV through pressurization for reformates showed a strong dependency on temperature due to changes in the equilibrium gas compositions of the fuel. Under load pressurization showed a positive effect on performance for all fuels. Power density increases of up to 70% were found with reformate as fuel.