Modeling Analysis of Different Renewable Fuels in an Anode Supported SOFC

It is expected that fuel cells will play a significant role in a future sustainable energy system. They are energy efficient, fuel can be produced nearly locally and, when a renewable fuel such as ethanol, methanol and biogas is used, there are no net emissions of greenhouse gases. Fuel cells have during recent years various progresses, but the technology is still in the early phases of development, however the potential is enormous. In this study a CFD approach (COMSOL Multiphysics) is employed to investigate effects of different fuels such as biogas, pre-reformed methanol, ethanol and natural gas. The fuel composition and inlet temperature are varied to study the effect on temperature distribution, molar fraction distribution and reforming reaction rates within a singe cell for an intermediate temperature solid oxide fuel cell (IT-SOFC). The developed model is based on the governing equations of heat-, mass- and momentum transport, which are solved together with global reforming kinetics. The result shows that the heat generation within the cell depends mainly on the initial fuel composition and the inlet temperature. The water-gas shift reaction proceeds to the right as hydrogen is consumed and water generated in the electrochemical reactions at the anodic three-phase boundaries.