Modeling and validation of planar solid oxide fuel cell stack operating with syngas

Abstract

Solid oxide fuel cells (SOFCs) are considered as a promising energy conversion device because of their high-energy efficiency and low pollutant emission. One advantage of SOFCs as compared to other types of conventional power egnerator is that they can convert not only hydrogen into electricity, but also carbon monoxide. This leads to a possibility in using varieties kinds of fuels, such as syngas (H2, CO, CO2 and N2). In this work, steady state mathematic two-dimensional model of planar SOFC operating with various syngas compositions for co-flow patterns is developed to describe a concentration distribution and cell performance or current density inside flow channels. Mass, species and charge conservation coupled with chemical and electrochemical reactions are considered in the model. The devdloped model presents a good agreement (similar trend) with the experimental results. A simulation result of the concentration distribution indicates that a water-gas shift (WGS) reaction plays an important role inside the flow channel and CO2 has the most negatively effect on the cell performance. Results from SEM and Eds show a change in morphology with some carbon deposition on the anode surface.