Green ammonia is ammonia (NH₃) produced using renewable electricity, green hydrogen, and nitrogen from the air. Unlike conventional ammonia—typically derived from fossil fuels—green ammonia is synthesized in a way that generates little to no carbon emissions. It is gaining recognition as a versatile, carbon-free energy carrier, a sustainable fertilizer, and a key enabler in the decarbonization of multiple sectors.
As global demand for clean energy alternatives grows, green ammonia is emerging as a strategic solution for energy storage, transport, and use in hard-to-decarbonize industries such as shipping, power generation, and agriculture.
What is Green Ammonia?
Traditional ammonia is produced using the Haber-Bosch process, which combines hydrogen (usually derived from natural gas) with nitrogen at high pressure and temperature. This process emits significant CO₂ due to the use of fossil fuels. In contrast, green ammonia replaces fossil-derived hydrogen with green hydrogen, which is generated via electrolysis using renewable electricity (from wind, solar, or hydropower). Nitrogen is obtained through air separation, and the two gases are then synthesized using a modified Haber-Bosch process powered by clean energy.
The overall reaction remains the same:
N₂ + 3H₂ → 2NH₃
However, when both inputs (hydrogen and electricity) are renewable, the result is carbon-free ammonia.
What is Green Ammonia used for?
Green ammonia has multiple current and emerging applications:
- Fertilizer production: Ammonia is the base chemical for nitrogen fertilizers. Green ammonia offers a sustainable way to produce fertilizer without CO₂ emissions.
- Shipping fuel: As a zero-carbon marine fuel, green ammonia is being explored for decarbonizing international shipping, offering an alternative to fossil bunker fuels.
- Power generation: Green ammonia can be burned in modified gas turbines or used in fuel cells to produce electricity, making it a promising energy storage medium.
- Hydrogen carrier: As a dense and easily liquefied compound, ammonia is an efficient way to store and transport hydrogen over long distances.
- Industrial decarbonization: It can be used as a feedstock for chemicals or as a direct fuel in high-temperature industrial processes.
Benefits of Green Ammonia
Green ammonia offers a wide range of benefits in the context of the energy transition and climate goals:
- Zero carbon emissions: When produced using green hydrogen and renewable electricity, the entire process is free of CO₂ emissions.
- Energy storage and transport: Ammonia is easier to store and ship than hydrogen, making it a practical solution for large-scale, long-term renewable energy storage and international trade.
- Infrastructure readiness: Ammonia transport and storage infrastructure already exists in the fertilizer and chemical industries, enabling faster deployment of green ammonia solutions.
- Versatility: It supports multiple sectors—from agriculture to power to maritime transport—enhancing its value across the energy system.
- Energy density: Ammonia has a higher volumetric energy density than hydrogen, making it more space-efficient as a fuel or storage medium.
Challenges
Despite its potential, green ammonia also faces a number of technical and economic challenges:
- Toxicity and handling: Ammonia is a hazardous substance that requires careful handling, storage, and regulation due to its toxicity and corrosive properties.
- Production cost: Green ammonia is currently more expensive than conventional ammonia due to the cost of green hydrogen and renewable electricity.
- Energy efficiency: The process of creating, storing, transporting, and using ammonia as a fuel involves multiple energy conversions, reducing overall efficiency compared to direct electrification.
- Technology readiness: While ammonia-fueled engines and turbines are in development, many applications—especially in power and transport—require further innovation and safety validation.
Regulatory gaps: Policies and standards for the use of ammonia as an energy carrier are still under development, and international collaboration is needed for cross-border trade and safety protocols,
