What is ammonia fuel?

When it comes to direct use, ammonia storage and handling systems leverage advanced features to ensure practical, safe and secure use in both energy and industrial applications. Commonly stored as a liquid under moderate pressure or at low temperatures, ammonia benefits from robust, well-established infrastructure that includes pressure-rated tanks and specialised containment systems designed to manage its volatility effectively.

Modern storage facilities integrate multiple safety mechanisms, such as pressure relief systems and real-time leak detection sensors, providing early warning and containment measures in the event of any release. Alongside proper monitoring and regular inspections, strict adherence to industry standards further enhances operational safety.

Unsurprisingly, ammonia emerges as a reliable choice for carbon-free sustainable energy solutions, with the added benefit of straightforward integration into existing storage and distribution networks.

As for indirect use, ammonia has gained popularity as a carbon-free fuel for power generation, transportation and industrial heating. However, ammonia combustion poses distinct challenges — its low reactivity, narrow flammability range and higher propensity to form nitrogen oxides (NOx) demand careful management. Compared to hydrogen and methane, ammonia exhibits a lower burning velocity and a more complex flame structure, leading to less efficient combustion and elevated NOx emissions.

To address these limitations, researchers have explored fuel blending, mixing ammonia with hydrogen or methane, to enhance flame speed and reduce ignition delay. Partial ammonia cracking has also proven effective, wherein a portion of ammonia is decomposed to hydrogen to improve reactivity. These approaches significantly increase the laminar burning velocity, making ammonia combustion more feasible for applications such as gas turbines.

Beyond its carbon-free benefits, ammonia combustion offers an important advantage in water-scarce environments. The flue gases produced during ammonia combustion contain a relatively high concentration of water vapour, which under standard cooling and condensation processes can be partially recovered. Studies indicate that up to one-third of this water vapour can be condensed and reused, reducing the need for external freshwater supply. In regions facing water stress, this recovery potential makes ammonia a particularly attractive fuel option, simultaneously addressing both energy decarbonisation and water conservation challenges.

Ammonia’s role as an efficient hydrogen carrier continues to gain traction, largely due to its high hydrogen content (17.6 percent by weight) and established global infrastructure. Transporting ammonia in liquid form requires moderate pressure (150–220 psi g) or temperatures around -33 °C (-28 °F), which is substantially less demanding than storing liquefied hydrogen at -252 °C (-423 °F). This attribute positions ammonia as a cost-effective medium for long-distance hydrogen transport.

Ammonia cracking — the decomposition of NH₃ into H₂ and N₂ — offers a direct pathway to hydrogen production at the point of use.

Coupling renewable generation with future fuel-based storage and power production offers a scalable model for data centres aiming to meet growing power demands without compromising on reliability or environmental performance. This integrated approach circumvents dependence on natural gas or CO₂ capture infrastructure, achieving near-zero operational emissions and reducing freshwater consumption through flue-gas condensation. Although front-end investment can be higher than conventional natural gas systems, ongoing reductions in the cost of wind, solar, electrolysers and ammonia conversion technologies hold promise for lowering the overall levelised cost of electricity.

By employing a behind-the-meter configuration, data centres gain independence from potential grid constraints and can better manage supply risks. As the industry moves toward increasingly energy-intensive AI workloads, greater collaboration among technology providers, engineering firms and regulatory bodies will be critical in advancing ammonia’s role as a practical, low-carbon fuel. Through these efforts, data centres can move beyond incremental efficiency improvements to embrace holistic, sustainable power solutions capable of meeting both current and future demands.