Biohythane (CH4/CO2/H2) is a gaseous mixture created by blending biogas (CH4/CO2) and biohydrogen (H2/CO2) produced from anaerobic digestion of biomass and waste. In this work, the performance and products of a commercially available anode-supported solid oxide fuel cell operating on simulated biohythane mixtures were characterised and compared with biogas. The kinetic performance of the cell was characterised using OCP, I-V and electrochemical impedance measurements. Gaseous outputs and fuel processing were characterised using quadrupole mass spectrometry. The work shows that between 0.6-0.9 V biohythane gave 9-22% better kinetic performance than biogas and that electrical power and syngas (H2/CO) can be produced simultaneously with complete disposal of CH4. The balance of electrical power and syngas production, as well as the composition of syngas, were easily controlled through adjustment of the cell voltage. H2/CO ratios in the range 1.1-4.0 were obtained in this work. Electrical power production occurred through H2 electrochemical oxidation and a mixture of partial (POx) and total (TOx) electrochemical oxidation of CH4. High voltages promoted POx and gave less electrical power, faster syngas production rates and lower H2/CO ratios, with the reverse observed at lower voltages. Increasing the H2 content of biohythane improved the kinetic performance of the cell to give more electrical power and, depending on the voltage, either more syngas with a lower H2/CO ratio (at low voltages), or slightly less syngas with a higher H2/CO ratio (at high voltages).
Original languageEnglish
JournalApplied Energy
StateIn preparation - 14 Mar 2019

    Research areas

  • Solid oxide fuel cell, biohythane, coproduction, fuel processing, synthesis gas, CO2 utilisation

ID: 3174832