Analysis and performance assessment of NH3 and H2 fed SOFC with proton-conducting electrolyte

The present paper investigates the performance of a solid oxide fuel cell based on proton-conducting electrolyte (SOFC-H⁺) using one-dimensional steady-state model. The analysis covers a detailed electro-chemical model for H₂ and NH₃ fuels. The direct internal reforming of NH₃ is examined, and the effects of some operating parameters (e.g. temperature, pressure, fuel utilization and oxidant utilization) on the reversible cell potential are investigated. In addition, the overpotentials (including activation, ohmic and concentration) are calculated to study the irreversible behavior of the SOFC-H⁺ with some actual data operating conditions and material properties taken from the literature. In addition, effects of some operation and structural parameters on cell performance were examined. The present results indicate that the activation and the ohmic losses are considerable. The concentration overpotential at the anode side is negligible due to the fact that H₂O is produced at the cathode side. The maximum power density is calculated as 3212 and 3113 W/m² at 1073 K and 1 atm for the fuels of H₂ and NH₃. The results further show that H₂ provides better performance than NH₃ at the same partial pressure. Moreover, NH₃ is an excellent hydrogen carrier which is a potential candidate for SOFC-H⁺ due to its high hydrogen content and considerable cell performance.