Solid Oxide Fuel Cells Utilizing Dimethyl Ether Fuel

The feasibility and benefits of using an oxygenated fuel for solid oxide fuel cell (SOFC) operation were explored using dimethyl ether (DME). A model for the flow tube chemistry was used to predict DME gas-phase decomposition kinetics and species concentration profiles for temperatures ranging from 550 to 750°C. The predictions, which were in good agreement with mass spectral measurements, showed that in the absence of a fuel cell DME decomposed primarily into equal amounts of and CO above about 675°C. The same decomposition species were observed in catalytic reaction experiments at Ni-based anodes, but the mole fractions of the decomposition gases were much higher, between 550 and 650°C. Current-voltage measurements were made using SOFCs with 100 μm thick yttria-stabilized zirconia electrolyte supports, cathodes, and 50 vol % Ni-based anodes. Maximum power densities for SOFCs supplied directly with DME fuel were 0.10 and at 600 and 700°C, respectively. No carbon deposition was observed in cells operated at temperatures up to 700°C. © 2002 The Electrochemical Society. All rights reserved.