Experimental investigation of improvement capability of ammonia fuel cell performance with addition of hydrogen

In this study, hydrogen is investigated as a source of performance improvement for alkaline electrolyte entailing direct ammonia fuel cells via dual fuel utilization. Membrane electrolytes are utilized with anion exchange characteristics and the fuel cell performance is investigated with pure ammonia, ammonia-hydrogen blends and pure hydrogen. The power density is observed to be 1990.8 mW/m² for pure ammonia fuel at peak point. However, this is found to increase to 2853 mW/m² and 4471 mW/m² when fuel blends of 80%NH₃-20%H₂ and 60%NH₃-40%H₂ are utilized respectively. The exergy efficiency at the maximum point power density increases from 14.2% to 22.1% and the energy efficiency rises from 15.2% to 22.8% as the fuel input is changed from pure ammonia to 60%NH₃-40%H₂ by mass. Also, the highest exergy efficiency of 29.1% and energy efficiency of 28.7% is obtained for the pure hydrogen fueled cell. In addition, the exergy destruction rate is determined to be 16.8 mW for the pure ammonia fuel cell at the maximum point power density, which decreases to 15.1 mW and 13.6 mW for 60%NH₃-40%H₂ and 80%NH₃-20%H₂ fuels respectively.