What is green ammonia, and what is it used for?

13 August, 2024

Green ammonia, like hydrogen and other renewable molecules, is a crucial energy carrier for achieving zero emissions and decarbonising the economy.

Interest in green ammonia has surged recently, as demonstrated by Enagás’ Call for Interest, which highlighted the national sector’s ambition to produce over 5 million tonnes of ammonia (NH3) annually, requiring approximately 0.9 million tonnes of hydrogen each year. Additionally, 41 companies revealed interest in using infrastructure for the transmission of around 4 million tonnes of ammonia per year.

From renewable hydrogen to green ammonia and other renewable molecules

Ammonia is a chemical compound made up of three hydrogen atoms and one nitrogen atom (NH3). It is mainly used in the production of fertilisers and industrial chemicals. In fact, it is the second most widely produced chemical in the industrial sector.

Ammonia is the second most widely produced chemical in the industrial sector

Ammonia can also serve as a renewable fuel, particularly for maritime transport, and as a carrier for renewable hydrogen, facilitating its transmission.

For ammonia to be classified as green, the hydrogen used in its production must be renewable. This means it must be synthesised from biomass or through a water electrolysis process powered by renewable electricity.

The study Innovation Outlook: Renewable Ammonia, published by IRENA (International Renewable Energy Agency), suggests that by 2050, the amount of green ammonia required to meet global demand for international maritime fuel could equal the current global production of ammonia.

According to this study, green ammonia is the best long-term candidate for the future fuel mix. The report says that a global investment of between 1.9 and 2.2 trillion dollars will be needed for green ammonia facilities.

Green ammonia is the best long-term candidate for the future fuel mix

Of this investment, 8% would be allocated to the demand side (storage at importing ports and shipping costs), while the remaining 92% would be directed towards the supply side (production, electricity, or storage at exporting ports).

Benefits of green ammonia

The main benefits of green ammonia production include:

• It does not emit polluting gases as it is produced using renewable energy sources, making it crucial for reducing emissions in sectors that currently use conventional ammonia.
• It is produced through a clean process, unlike other energies such as oil or coal.
• Its energy density per volume is higher than that of hydrogen, requiring less space to store energy. This makes it an attractive fuel for transporting large loads over long distances, such as in maritime shipping. Green ammonia is versatile in both liquid and gaseous forms. It can be transported in cylinders to hard-to-reach areas or stored in tanks at industrial sites.
• Its production costs are low. By using renewable energy sources, green ammonia reduces exposure to the volatility of fossil fuel prices.
• It can support emerging economies that are also committed to sustainable energy. In regions with limited access to renewable energy, green ammonia can serve as an important clean fuel.
• Green ammonia is a green alternative for the manufacture of more sustainable chemicals.
• It can be used as a fuel in both the agricultural and maritime industries, contributing significantly to the EU’s 2050 decarbonisation goals.