The lowest cost way to use ammonia as a fuel is as an intact NH3 molecule. However, its slow flame speed can cause challenges managing flame stability, ammonia slip, and nitrogen oxide formation. Some fuel cells also require hydrogen, rather than ammonia. Ammonia cracking can solve these problems by providing either a NH3 + H2 + N2 blend or, with appropriate processing, pure hydrogen. Starfire Energy’s Prometheus cracking technology is a unique approach that uses an oxide catalyst bonded to a metal foil substrate. It provides excellent opportunities to power the cracking reaction with both waste combustion heat or purpose-generated…

Traditional ammonia cracking is achieved at 850-950 °C in the presence of a nickel catalyst. The reaction is highly endothermic, and maintaining these high temperatures at high flow rates of ammonia gas can be difficult. Here, we present work using our advanced ammonia synthesis catalyst in an ammonia cracking setup. We use a metallic monolith catalyst support to minimize pressure drop at high flow rates. Full NH3 cracking occurs at 600 °C, with the onset of cracking at 400 °C. An output flame can be achieved with a fully tunable ratio of hydrogen to ammonia, depending on the temperature setpoint…

The traditional Haber-Bosch (HB) synthesis of anhydrous ammonia will adapt to clean power by sourcing the hydrogen from renewable electrolysis. However, the very large scale of current HB plant designs are not well-matched to smaller and more distributed clean power resources. Plant/reactor designs need to be made at a smaller scale in order to best utilize clean hydrogen. Small, megawatt scale HB reactors have an additional advantage of being better able ramp up and down with variable renewable power. This talk will detail ARPA-e funded work into the design and optimization of these smaller, clean NH3 reactors, which utilize much…

Starfire Energy is developing a fast-ramping reactor for making CO2-free NH3 for fuel, energy storage, and agricultural applications. A fast-ramping reactor is desired to follow (a) variable electricity generation from CO2-free sources such wind and solar power plants or (b) variable availability from CO2-free baseload electricity generation such as nuclear or hydroelectric power plants. The reactor builds upon the Haber-Bosch process by (a) introducing a higher activity supported Ru catalyst (over 4.5 mmol g-1 h-1 at 1 atm and over 45 mmol g-1 h-1 at 10 atm) and (b) further enhancing the catalysis by applying an electric potential or electric…