Ammonia is utilized in a variety of industries with 80% of produced ammonia used for fertilizer production. Most commercial ammonia is produced using the Haber-Bosch (HB) process, which requires high temperatures and pressures, resulting in high operational/production costs. The process typically uses natural gas as the feedstock for H₂ production through a conversion process that releases CO₂ emissions (e.g., SMR). The produced H₂ is reacted with N₂ using a metal catalyst (e.g., iron-based, Ru, 4% CsRu/MgO) to produce ammonia.

The Need

Alternative, more sustainable ammonia production pathways are required to address concerns and limitations with the HB processes’ high energy requirements and elevated CO2 emissions levels.

The Technology

A new ammonia production technology using an oxygen ion conductive solid oxide electrolyte cell (SOEC) reactor and a novel cathode material has been developed that exhibits ionic/electronic conductivity and activity towards ammonia production from N₂ and H₂O. The performance of a doped lanthanum ferrite-type perovskite material is enhanced by incorporating a Fe3N-type active phase. With this cathode, the reduction of H₂O is realized by the lanthanum ferrite phase, and the activation of the N₂ gas phase is achieved by an iron nitride phase. The reduction of H₂O produces H₂ and oxide ions which are transported to the anode side through the electrolyte. The generated H₂ reacts with N atoms in the iron nitride lattice forming ammonia. Testing indicated that ammonia production using a Fe₃N-enhanced cathode was 2X greater than a non-Fe₃N cathode.

Commercial Applications

• Ammonia production

• Fertilizer production

• Protein in livestock feed, cleaning agents, water/wastewater treatment, metal treating, industrial refrigeration systems, rubber production, coated papers, leather tanning

Benefits/Advantages

• H₂O as a H₂ source eliminates CO₂ emissions produced with the HB process

• SOEC production of ammonia performed at atmospheric pressure reduces energy requirements and alleviates safety issues as compared to the high pressures required in the HB technique

• The developed LSNF perovskite is tunable, and enhancement with Fe₃N results in excellent ammonia production capabilities