Solid oxide fuel cells and biogas

Figure 1: Advantage of solid oxide fuel cells in comparison to combustion engines to utilize landfill gas (biogas) to electricity and heat. (Source: Langnickel, H. et al. (2018). Galvanostatic and potentiostatic operation of real landfill gas fueled SOFCs. Proceedings of the 13th European Sofc Soe Forum 2018.)

It is general agreed that due to the increasing amount of renewable energy in the electricity production different energy conversion and storage technologies are needed to ensure a 100% availability of electricity. One attractive medium is fuel derived from biomass. Biogas consists of methane and carbon dioxide plus some traces of other gases such as sulfur components. Biomass is a rare resource and has to be used in an efficient way. Whereas in commercial biogas power plants biogas is burned off with low efficient combustion engines, solid oxide fuel cells (SOFC’s) could be a more efficient way. Furthermore, most biogases are unattractive for combustion engines due to their low heating values. With SOFC’s it is possible to convert hydrogen or carbon containing fuels, as for example biogas, directly into electricity and the side product heat in a high efficient way.

The aim of this PhD project is the integration of SOFC’s with biogas as fuel. With the partner Odense Renovation, the potential of using real landfill gas (biogas) from a landfill unit and making it available in the SOFC through dry reforming will be explored. The activities will be related to the cell level, the stack level and the system level. On the cell level, the composition of the biogas and the needed reactant (CO2/Steam) will be variated and analyzed. Furthermore, anode fuel recirculation will be considered. This is important to prevent carbon formation on the anode side of the fuel cell. On the stack level, investigations will be carried out to determine the durability and degradation mechanisms of the SOFC-Stack. On the system level, theoretical studies will be carried out for the whole system integration, including system layout, capacities, and efficiencies.

Funding agency

Odense Renovation A/S