SOFC fuelled with reformed urea

Solid Oxide Fuel Cell (SOFC) can be operated with a wide variety of fuels and in a large range of operating conditions. Taking advantage of high temperature and nickel based catalysts several compounds such as methane, ethanol and ammonia can be internally reformed or thermally decomposed producing hydrogen rich gas streams. In this study urea was investigated as a potential fuel for SOFC, since it is a widely available product in the fertilizers' market, safe to be handled and used, and can be recovered from biomass or water treatment plants as a byproduct. An additional pathway for green urea can be based on green hydrogen via electrolysis powered by renewable energy sources and CO2 recovered from carbon capture plants. Urea decomposition was studied and reproduced in the experimental activity to evaluate its effect on the performance of SOFCs. A gas stream, obtained by simulating decomposed urea with technical gases mixtures, was fed into an SOFC stack, varying the operational temperature and the steam to carbon ratio. Experimental results produced efficiencies higher than 40%. Based on experimental data a 0-D model was developed and operational conditions were expanded, reaching an overall efficiency of 60%. (C) 2015 Elsevier Ltd. All rights reserved.