Temkin-Pyzhev Kinetics in Intermediate Temperature Ammonia-Fed Solid Oxide Fuel Cells (SOFCs)

Two recent trends in fuel cell development are the use of ammonia as a fuel, and the preference for intermediate temperature operation of solid oxide fuel cells. There have been a few mathematical models of ammonia-fed solid oxide fuel cells reported in the literature, all of which are for high temperature operation where Tamaru kinetics applies. To date, there have been no models reported for intermediate temperature operation. At intermediate temperatures, hydrogen inhibition of ammonia decomposition occurs and hence the Temkin-Pyzhev model of ammonia decomposition must be employed. This paper is the first to present a two-dimensional computational model of an intermediate temperature ammonia-fed solid oxide fuel cell with Temkin-Pyzhev ammonia decomposition kinetics. The results show that the problem of thermal shock associated with high temperature ammonia-fed fuel cells is alleviated at intermediate temperature operation.