On analysis of chemical reactions coupled gas flows in SOFCs

Abstract

Solid oxide fuel cell (SOFC) is among others one of the most promising technologies for electricity energy generation. A recent new trends is to reduce its operating temperature from 1000oC to 800oC by employing a thick porous layer as the supporting structure. Various transport processes occurred are strongly affected by catalytic chemical/electrochemical reactions appearing in nano- or/and microstructured and multi-functional porous electrodes. It is particularly true if methane is used as the fuel, and internal reforming reactions within the microstructured porous anodes enable the conversion of the methane into H2 and CO. To deeply understand the chemical reaction coupled gas flow and heat transfer in the microstructured porous anode, a fully three-dimensional numerical calculation procedure (CFD) is developed and applied. The species mass/heat generation and consumption related to the internal reforming reactions and the electrochemical reaction have been identified and employed in the study. The variable thermalphysical properties and transport parameters of the fuel gas mixture have also been taken into account. Furthermore, the heat transfer due to the fuel gas flow is implemented into the energy balance based on multi-component diffusion models. Finally, various issues connecting to the micro models of the surface reactions are discussed and reviewed.