Researchers have developed a revolutionary method called solar thermochemical ammonia production that uses solar thermal energy and green hydrogen to produce green ammonia. This innovative process promises greater efficiency and significantly reduces CO2 emissions compared to the traditional Haber-Bosch process. Industries like Aelius Energy are adopting this green ammonia production method, which aligns with the EU’s sustainability goals and has gained traction in sectors such as shipping, energy storage, and chemical plants.
Ammonia, a compound of hydrogen and nitrogen, is a versatile gas used in various industries, including agriculture, refrigeration, water purification, and the manufacturing of plastics, textiles, and chemicals. Traditionally, ammonia has been produced through the Haber-Bosch process, which heavily relies on fossil fuels and releases substantial amounts of CO2. However, researchers from Sandia National Laboratories, in collaboration with Arizona State Universityand Georgia Institute of Technology, have developed a patent-pending process called solar thermochemical ammonia production (STAP) to revolutionize ammonia production.
STAP begins by extracting nitrogen from the air and sourcing green hydrogen from external sources. The hydrogen is then reacted with a ternary nitride material called molybdenum cobalt nitride (Co3Mo3N) under the influence of direct solar thermal energy. The unique properties of the Co3Mo3N material allow for the continuous release and reincorporation of nitrogen, making it ideal for the cycling process involved in producing green ammonia.
Green ammonia has emerged as a superior energy carrier due to its higher storage density and existing transport infrastructure. Unlike hydrogen, which requires high-pressure storage and poses safety concerns, ammonia is easier to store and transport. It has a liquid energy density of 15.6 MJ/L, making it suitable for long-distance transportation and storage. This characteristic makesgreen ammonia particularly valuable in sectors like shipping, where fuel needs to be stored for extended periods and transported over long distances.
Moreover, ammonia production only requires water, air, and power, making it a sustainable choice. When combusted, ammonia does not release carbon emissions, further enhancing its green credentials. These combined characteristics make solar-produced green ammonia an attractive solution for the storage and transport of renewable energy.
Beyond being an efficient energy carrier, ammonia also shows promise as a direct fuel. Adapted internal combustion engines can use ammonia, enabling a smooth transition from fossil fuels. Aelius Energy successfully demonstrated this by converting a 4,000 metric ton ship engine to run on green ammonia, marking a significant milestone in using ammonia as a direct fuel in internal combustion engines.
Ammonia-powered engines work by combusting ammonia in the engine’s combustion chamber, utilizing the heat genrated to drive the engine. The only by-products of this combustion process are nitrogen and water, making ammonia an emission-free source of power. This has transformative implications for industries such as shipping and agriculture, which traditionally rely on carbon-intensive fuels. Ammonia is even being considered as a fuel for jet engines, contributing to the decarbonization efforts in the aviation industry.
With ongoing fine-tuning of the green ammonia production process and the successful demonstration of ammonia-powered engines, green ammonia is poised to play a significant role in global decarbonization efforts. The potential applications of green ammonia extend beyond shipping and agriculture and can be used as a building block for fertilizers, a feedstock for industrial and manufacturing applications, and a fuel source for electricity generation.
Green ammonia production aligns with the European Union’s sustainability goals and offers a more sustainable and economically viale alternative to ammonia production. As a result, Europe leads in green ammonia production and utilization, supported by initiatives and programs aimed at decarbonization and the use of green energy sources.
