Comparative study on thermodynamic analysis of solid oxide fuel cells supplied with methanol or ammonia

Abstract

The increasing demand for green hydrogen and power production necessitates the development of novel and upgraded power generation technologies. The solid oxide fuel cell combined heat and power (SOFC–CHP) system is a promising solution due to its high efficiency, clean operation, and fuel flexibility. In practical terms, SOFCs can operate using a variety of fuels such as alcoholic fuel, hydrogen, ammonia, etc. Recently, methanol and ammonia have become noteworthy alternative fuel options as it possesses advantages such as low transportation cost and high hydrogen storage capacity. In this paper, we have established two SOFC–CHP models fueled by methanol or ammonia integrated with the steam Rankine cycle. A comprehensive thermodynamic model is proposed for energy and exergy analyses. Sensitivity analysis is performed to study the system's characteristics. The results show that the SOFC–CHP system fueled by ammonia exhibits superior performance, the maximum electrical power, efficiency, and exergy efficiency is 430W, 7% and 10% greater than the methanol fueled system. The operating temperature is about 30K higher in methanol supplied system. The largest thermal power difference can reach 0.65 kW. Overall, the ammonia fueled SOFC–CHP system shows greater potential than that fueled by methanol.