Ammonia, a natural gas used in fertilizers and as an energy carrier, has the potential to go green.
Ammonia binds airborne nitrogen, an important crop nutrient, and makes it available for plants to access through the soil. Approximately 70% of ammonia is used to make fertilizers. Ammonia-based fertilizers revolutionized agriculture in the early 1900s, doubling the number of people who could be fed off one acre of land.
Though the chemical is the second-most produced in the world and remains vital to feeding a rapidly growing global population, conventional ammonia production uses greenhouse gases.
The chemical is created via the Haber-Bosch process, which is typically powered by fossil fuels, and utilizes hydrogen, 96% of which is also derived from fossil fuels. Ammonia production accounts for over 1% of global CO2 emissions from the energy sector.
‘Green ammonia,’ however, offers a more sustainable alternative to conventionally produced ammonia. It is created using ‘green’ hydrogen, itself produced using 100% renewable energy from sources like wind and solar.
Not only is ammonia vital to the global food system, but it also has potential as an energy carrier. The hydrogen present in liquid ammonia has a volumetric energy density 1.5 times higher than that of liquid hydrogen, and more than twice that of hydrogen gas. It’s low vapor pressure makes ammonia less dangerous to handle than hydrogen, making it a more attractive option for storing and transporting large amounts of energy.
Green ammonia can be used in fertilizers, as a fuel source in transportation and industry, and to generate electricity. The African Hydrogen Partnership has identified various regions in sub-Saharan Africa with conditions suitable to establish green hydrogen hubs, which will be key in future green ammonia production.
Using green hydrogen is vital to more sustainable ammonia production and the transition away from a high-carbon economy.