Biogas‐fed Solid Oxide Fuel Cell (SOFC) systems can be considered as interesting integrated systems in the framework of distributed power generation. In particular, bio‐methane and bio‐hydrogen produced from anaerobic digestion of organic wastes represent renewable carbon‐neutral fuels for high efficiency electrochemical generators.With such non‐conventional mixtures fed to the anode of the SOFC, the interest lies in understanding the multi‐physics phenomena there occurring and optimizing the geometric and operation parameters of the SOFC, while avoiding operating and fuel conditions that can lead to or accelerate degradation processes.In this study, an anode‐supported (Ni‐YSZ) tubular SOFC was considered; the tubular geometry enables a relatively easy separation of the air and fuel reactants and it allows one to evaluate the temperature field of the fuel gas inside the tube, which is strictly related to the electrochemical and heterogeneous chemical reactions occurring within the anode volume.The experiments have been designed to analyze the behavior of the cell under different load and fuel utilization (FU) conditions, providing efficiency maps for both fuels.The experimental results were used to validate a multi‐physics model of the tubular cell. The model showed to be in good agreement with the experimental data, and was used to study the sensitive of some selected geometrical parameters modification over the cell performances.

Biogas-fed SOFC systems can be considered as interesting power systems in the framework of distributed generation plants. In particular, bio-methane (CH4/CO2 60/40 vol.) and bio-hydrogen (H2/CO2 50/50 vol.), produced from anaerobic digestion of wastes, represent renewable fuels for high efficiency electrochemical generators. This study investigates the behavior of an anode-supported (Ni-YSZ) tubular cell fed by the two fuels. The tubular geometry has been considered since it causes a complete separation of the electrodes reactants, allowing the analysis of the evolution of the fuel gas inside the tube, in terms of composition (consequence of electrochemical and heterogeneous chemical reactions) and temperature field. The experiments have been designed in order to analyse the behavior under different load and fuel utilization conditions. In particular, the fuel mixtures have been conditioned to avoid carbon build-up on the anode electrode. The experimental results have been then used to validate a 2D model (taking into account the cell axial symmetry) of the multi-physics phenomena occurring along the tubular cell. The model shows a good accordance with the experimental data, and has therefore been used to analyse the effects linked to the modification of some geometrical parameters of the tube in terms of performance of the cell.