Journal of Power Sources, Vol.206, 171-178, 2012
A modified dusty gas model in the form of a Fick's model for the prediction of multicomponent mass transport in a solid oxide fuel cell anode
The dusty gas model (DGM) is accurate but difficult to use for describing multicomponent mass transport in porous media. Based on a reasonable approximation that is exact for binary mixtures, the DGM is reformulated in the form of a Fick's model with explicit analytical expressions for the flux of each species. The validity of the new formulation, the DGMFM, is tested using a numerical model of a solid oxide fuel cell (SOFC) anode with realistic microstructure data and partially reformed methane fuel. Methane steam reforming and the water gas-shift reaction in the anode are included in the model. The accuracy of the DGMFM is checked by systematically varying the factors that may affect the mass transport in the porous anode, such as the pore radius, porosity, tortuosity factor, anode thickness, temperature, current density and fuel composition. The comprehensive study shows conclusively that the DGMFM is highly accurate in reproducing the DGM results for all practical SOFC operations. (C) 2012 Elsevier B.V. All rights reserved.