Decarbonisation of natural gas grids across the world is essential due to increasing heat and electricity demand and associated emissions of greenhouse gases and air pollutants. In this work, the performance and fuel processing of a commercially available anode-supported solid oxide fuel cell (SOFC) is studied to evaluate the response of a CH4-fed SOFC to natural gas decarbonisation using biohydrogen (H2/CO2). Cell performance is characterised current-voltage curves and electrochemical impedance spectroscopy. Fuel processing is characterised using quadrupole mass spectroscopy. It is shown that substituting between 50-60 vol% CH4 with biohydrogen substantially improved SOFC efficiency by 56-90% compared with pure CH4. This is due to greater CH4 conversion in dry reforming and a switch to electrochemical H2 oxidation as the primary power production pathway. The efficiency can be increased by another 100-110% by increasing the operating temperature to 800 °C, which further improves catalytic CH4 conversion and accelerates electrochemical H2 conversion. Substituting anywhere between 20-80 vol% CH4 with biohydrogen improves SOFC performance to some degree compared with pure CH4; only under pure biohydrogen is the performance worse due to the very low calorific value of the fuel. The presence of CH4 cracking is also decreased by addition of biohydrogen to CH4.
Original languageEnglish
JournalJournal of Power Sources
StateIn preparation - 14 Mar 2019

    Research areas

  • Anaerobic digestion, Biogas, Biohythane, Natural gas, Decarbonisation, Heat

ID: 3174861