Experimental and modeling investigation of IT-SOFC for use with biogas and syngas mixtures

SDC electrolyte-supported IT-SOFCs with Cu-Pd-CZ80 composite anodes and LSCF cathodes were tested under a wide range of operating conditions. Polarization and EIS measurements were collected at 650°C and 600°C with syngas mixtures (2.3-0.4 H2/CO ratio), H2/N2 mixtures (97-30% H2 v/v) and CO/CO2 mixtures (97-50% CO v/v). In the presence of syngas, a co-oxidation route was active, wherein H2 and CO were electro-oxidized in parallel and contemporarily. A 1D, dynamic and heterogeneous model of the cell was applied to analyze the polarization and the EIS curves. The kinetics of the reactions of H2 electro-oxidation, CO electro-oxidation and O2 reduction were individually investigated and global power law rates were derived. The syngas experiments were simulated on a fully predictive basis, confirming that the polarization behavior could be reproduced exclusively by assuming the presence of the co-oxidative route. The cell was also exposed to biogas, revealing that dryreforming was active.