Model development and validation of solid oxide fuel cells using hydrogen-water-carbon monoxide-carbon dioxide mixtures: From button cell experiments to tubular and planar cells.

摘要

Increasing awareness of climate change due to greenhouse gases emissions, especially CO2, has caused governments, industries and research organizations to develop more efficient and cleaner technologies for power production. In this context, fuel cells and particularly solid oxide fuel cells (SOFCs) for stationary applications, show great promise. One important feature of SOFCs is the ability to use a wide range of fuels. For example, they can operate with synthesis gas mixtures (H2 and CO) since CO does not poison the anode electrocatalyst. Synthesis gases can be produced from a wide variety of primary fuels, such as coal, biomass, and oil. If sulphur is present in the primary fuel, H2S will be present in the synthesis gas, which can have a major detrimental effect on the cell performance. The presence of H2S was not considered in this work. Instead, we focus principally on the effect of the presence of high amount of CO in the synthesis gas.; This thesis presents a systematic approach to develop and validate a mechanistic model of a single cell SOFC operating with mixtures of H 2, CO, H2O, CO2 and N2. The model has been developed for various configurations, from a bench-scale button cell to commercial-scale cells including a cathode-supported tubular SOFC and an anode-supported planar SOFC. An important feature of this model is that it considers both H2 and CO oxidation reactions simultaneously. The experimental work was undertaken in the MTEC (the National Metals and Materials Technology Centre) laboratory in Bangkok, Thailand and the modelling work was undertaken in the Department of Chemical Engineering at the University of Waterloo.; The model was validated using experimental data obtained from a bench-scale button cell at the MTEC. The experimental work was also conducted to study the effect of simulated synthesis gas composition on cell performance and cell degradation. It was found that the cell power obtained from humidified H2 is greater than that achieved from synthesis gases since the fuels (H2 and CO) in the synthesis gas were diluted with high amounts of CO2 and N2. (Abstract shortened by UMI.)