A COX-free 1 kW-class hydrogen power pack fueled by liquid ammonia is presented. Ru catalysts supported on La-doped alumina (Ru/La(x)-Al2O3) were pelletized by varying the lanthanum doping content (x mol%) to control catalytic activities. An optimized Ru(1.06 wt%)/La(20)-Al2O3 pellet catalyst presents a &gt;99.7% conversion efficiency at 500 °C under a gas hourly space velocity of 5000 mL gcat-1 h-1. The integrated power-pack system composed of a dehydrogenation reactor, adsorbents, and a 1 kW-class polymer electrolyte fuel cell, can convert 9 L min-1 of ammonia into 13.4 L min-1 of hydrogen, powering a 1 kW-class fuel-cell continuously for &gt; 2 h without any performance degradation. To achieve autothermal and COX-free operations, heat required for ammonia dehydrogenation was provided by unutilized hydrogen from the fuel cell, drastically increasing the overall efficiency of the system to &gt;49% while removing the external carbon heat source. Finally, a drone tethered to the system was operated, demonstrating the feasibility of an elongated flight time of &gt;4 h, much longer than 14 min with a Li-polymer battery loaded on the drone. The system is expected to meet the United States Department of Energy's 2020 gravimetric and volumetric hydrogen storage targets of 4.5 wt% and 30 gH2 L-1 at system weights of 43 kg and 50 kg, respectively.

Ammonia as an efficient COX-free hydrogen carrier: Fundamentals and applications

2019 Spring National Meeting

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