In the present study a comprehensive numerical model of a planar cross-flow electrolyte-supported solid oxide fuel cell (SOFC) is reported. This model is solved in a 3D environment using COMSOL Multiphysics software. To verify the simulation results, an experimental set-up of a six-cell stack was built. Cell temperature and current-voltage measurements are used for validation of the simulation results. Good agreement between the simulation results and the experimental measurements is achieved. Temperature validation in addition to the popular current/voltage validation ensures that the model performs well in predicting local processes like chemical reactions. In this study methane-free biogas (CO2 + H-2) is fed to the SOFC, and the performance of the system is investigated and explained. It is concluded that the methane-free biogas reduces the cooling air flow due to endothermic reverse water gas shift reaction and gives better current density distribution over the cell compared to hydrogen. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.