(471j) Ammonia for Gas Turbines Fuelling - European Progress

A hydrogen economy has been the focus of researchers and developers over the decades. However, the complexity of moving and storing hydrogen has always been a major obstacle to deploy the concept. Therefore, other materials can be employed to improve handling whilst reducing cost over long distances and long periods. Ammonia, a highly hydrogenated molecule, can be used to store and distribute hydrogen easily, as the molecule has been employed for more than 120 years for fertilizer purposes. Being a carbon-free chemical, ammonia (NH3) has the potential to support a hydrogen transition thus decarbonising transport, power and industries.

However, the complexity of using ammonia for power generation lays on the appropriate use of the chemical to reach high power outputs combined with currently low efficiencies that bring up overall costs. This complex scenario is also linked to the production of combustion profiles that tend to be highly polluting (with high NOx emissions and slipped unburned ammonia). There is still no technology capable of using ammonia whilst producing both low emissions and high efficiencies in large power generation devices, thus efficiently enabling the recovery of hydrogen and reconversion of stranded, green energy that can be fed back to the grid. Tackling these problems can resolve one of the most important barriers in the use of such a molecule and storage of renewable energies. Many countries have recently engaged in ambitious programs to resolve these issues, aiming for large power units to run on ammonia by 2030. Thus, European counterparts need also to engage in these technological advancements to fully unlock a hydrogen, cost-effective economy.

Therefore, the current presentation provides an insight of British led attempts to support the transition towards a zero-carbon economy via ammonia. Ammonia has recently been recognised for its potential to fuel gas turbines. Works around the subject have focused on the use of pure ammonia or its various blends to enable the production of extra power using stranded renewable energy converted into this hydrogen carrier. Therefore, interest across Europe has followed current developments from Japan in order to ensure that European technologies are capable of using the chemical without incurring into large amounts of emissions, operational problems or flame instabilities. Projects go from small power units to large power and propulsion applications establishing new set of guidelines to employ ammonia blends for the production of zero-carbon power.

Results demonstrate that ammonia can support the transition towards a zero-carbon economy, producing negligible emissions due to the self-consuming effect of unwanted nitrogen oxides. Moreover, doping and improved injection strategies have shown enhanced stability, with new trials that have been conceived to determine the impact of these aggressive atmospheres towards hot combustor components. Numerical simulations and fundamental studies, also employed to define new insights into the chemistry of these blends, have evolved to ensure that complex designing tools (i.e. DNS/LES CFD) can be afforded for more accurate designs. All these works go hand-by-hand to demonstrate the potential of ammonia to supplement the long-time storage capability of hydrogenated fuels in gas turbines. Therefore, apart from all these crucial points, this presentation will also highlight efforts that Europe has mustered to remain a key player around the subject.