Solid oxide cells (SOCs) are highly efficient electrochemical energy conversion devices, which can produce electrical power and heat in fuel cell mode, or valuable chemical products such as synthesis gas (H2/CO) in electrolysis mode. Their fuel flexibility enables utilisation of biofuels produced from anaerobic digestion (AD) and dark fermentation processes. Effluent from dark fermentation can be utilised as a substrate in methanogenic AD in a two-stage process (see Fig. 1), resulting in a more efficient fermentation overall. This produces a gaseous mixture predominantly consisting of 10:60:30 vol% H2/CH4/CO2. In this work, the utilisation and fuel variability of H2/CH4/CO2 mixtures in an anode-supported SOC were investigated. The SOC operated in fuel cell mode was able to produce power, heat and synthetic gas (H2/CO). CO2 reforming and CH4 decomposition reactions were responsible for producing H2 which, influenced the cell performance largely by being present in the anode. As shown by the results H2 was found to have a very big effect on the open circuit potential (OCP), increasing H2 reduces activation losses. H2 production increased within the range of 0-40 vol% of CH4 being present, while 40-80 vol% of CH4 resulted in an overall reduction of cell performance.
Original languageEnglish
JournalInternational Journal of Hydrogen Energy
StateIn preparation - 14 Mar 2019

    Research areas

  • Biogas, Biohythane, biomass, solid oxide fuel cell, synthesis gas, renewable energy

ID: 3174861