Renewable Ammonia for a Sustainable Energy Future

Ammonia shows great potential as a renewable energy vector due to its ease of storage and high energy density. Technological advances and policy measures will be critical to enable its wide adoption.

Ammonia is, at present, essential for agriculture. In 2020, over 144 million m.t. of ammonia were produced globally (1), 80% of which was used as nitrogen-delivering fertilizer either directly or as a precursor. Ammonia is also used in cleaners, as a refrigerant, and in the manufacture of plastics, explosives, textiles, and other chemicals. Currently, ammonia’s use as an energy vector accounts for less than 1% of the global total. However, it has considerable promise as a multifaceted energy vector to facilitate a transition to renewables-dominant energy systems. The potential of ammonia in energy applications has spurred rapid growth in both research and commercialization activities.

This article introduces ammonia in the context of its advantages in energy applications and provides an overview of renewable ammonia utilization and production concepts, associated technologies, and their state of development. The focus for ammonia utilization is on two applications with broad implications: transportation, either as a hydrogen carrier or directly as a fuel, and renewable energy storage. The viability of ammonia-enabled sustainable energy depends on its renewable production. Thus, this article also provides a survey of sustainable ammonia production projects and outlines potential advances in process design and operations to make ammonia synthesis better suited to intermittent renewables. Finally, the broader challenges and potential solutions for widespread implementation of ammonia energy systems are discussed...