Carbon Oxidation in Fuel Cells and H2 Production

High temperature direct carbon fuel cells (DCFCs) offer potentially high efficiencies for conversion of the chemical energy of solid carbonaceous fuel(s) into electrical energy. DCFCs with molten metal anodes consume carbonaceous fuels by oxygen dissolved within the melt, which functions as an anode in an otherwise conventional solid oxide fuel cell (SOFC). Such reactors can also be used in electrolytic mode for reducing steam to hydrogen at the cathode, which enables the specific electrical energy consumption for H-2 production to be decreased compared with conventional steam electrolysis. 2-D models have been developed to predict the behavior of a micro-tubular hollow fiber SOFC (ca. 1 mm ID) with a molten metal (Sn) anode, using assumed values for the anode exchange current density. Results are reported for the temperature dependence of open circuit potentials for the reactor: Sn vertical bar SnO2 vertical bar YSZ vertical bar Air measured using a pellet cell and compared with thermodynamic predictions.