Kinetic Study of Carbon Deposition in Solid Oxide Fuel Cells (SOFCs)

Abstract

Owing to many irreplaceable advances, solid oxide fuel cells (SOFCs) have a promising and competitive potential in the application of green power supply and greenhouse gas reduction. Especially the utilization of biomass-derived syngas shows a high efficiency potential for the overall system. However, carbon deposition at the anode is a major challenge for the practical application. Once carbon deposited at the anode, the degradation of SOFC performance is permanent and irreversible to a certain extent. The carbon deposition is closely associated with the inner temperature distribution and fuel gas composition within the SOFCs, which is determined by complex chemical and electrochemical reactions. In this study, competing kinetic rates for carbon deposition and regasification are analyzed based on CFD methods for typical biomass-derived syngas compositions. Based on this method, reasonable operating conditions and flow field configuration can be recommended, which reduce the kinetic rate of carbon deposition at the SOFC anode. It is also worth mentioning that the specific anode area where carbon deposition occurs firstly will be detected numerically under different fuel gas components, operating temperatures and flow filed configurations. In summary, an effective method is provided to reduce the carbon deposition at the anode and improve the life expectancy of SOFCs, which is meaningful for SOFC design and operation in practical applications.