Multi-component mathematical model of SOFC anode using coal gasified fuel. Paper no. IGEC-1-048

Solid oxide fuel cell (SOFC) is a ceramic cell, typically operating around 1000oC. SOFC is promising for electric utility power generation in both large central power plants and decentralized generation units. Both hydrogen and carbon monoxide can be used as a fuel, either directly or indirectly through the water-gas shift reaction, thus providing the flexibility on fuel choice. Therefore, in the present study, a mathematical model of SOFC anode using coal gasified fuel has been developed. The model includes the water-gas shift reaction in the anode electrode (backing) layer and the spatially-resolved electrochemical reaction in the reaction zone layer. The modified Stefan-Maxwell equations incorporating Knudsen diffusion were used to model multi-component diffusion inside the porous electrode (backing) and reaction zone layers. Moreover, the general Butler-Volmer equation was used to model electrochemical reaction in the reaction zone layer. The model can predict the distribution of species, electronic and ionic potentials in the porous electrode (backing) and reaction zone layers, yielding the anode performance under various operating and design conditions. It is found that the consideration of water-gas shift reaction in the anode electrode (backing) layer and spatially-resolved electrochemical reaction in the reaction zone layer yields a higher concentration of H2 at the end of anode electrode layer, and thus helps in minimizing the concentration overpotential. (author)