Study of Methane Steam Reforming kinetics in operating Solid Oxide Fuel Cells: Influence of current density

摘要

In literature, little is reported on the experimental studies of Methane Steam Reforming (MSR) kinetics in Solid Oxide Fuel Cells (SOFCs) when a current is drawn. This work investigates MSR reaction kinetics in a complete SOFC with a Ni-Gd0.1Ce0.9O2-delta (Ni-GDC) anode under varying gas compositions, operating temperatures and current densities in order to obtain reliable experimental data for Computational Fluid Dynamics (CFD) modeling studies. Consistent with previous work, the methane conversion X-CH4 decreases as the temperature decreases. A slight increase in the MSR reaction rate is observed when a current is drawn. A positive dependency of the MSR reaction rate on methane concentration was found. Current has an insignificant influence on the methane reaction order. Under open-circuit working condition, steam concentration has a slightly positive influence at higher temperature and a slightly negative influence at lower temperature on the MSR reaction rate. The influence of steam concentration on the reaction rate becomes more negative when a current is drawn. It is probably due to the blockage of reaction sites by the adsorbed oxygen/water molecules/ions. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.