Abstract
Ammonia is attracting growing interest as a carbon-free fuel for power generation thanks to its ease of storage, transport, and established distribution infrastructure. However, its low reactivity and fuel-bound nitrogen make direct use in gas turbines challenging, leading to flame stability issues and high NOx and N2O emissions. While recent laboratory and micro-gas turbine scale studies have demonstrated the feasibility of pure ammonia combustion, validated burner designs developed to industrial standards and tested at gas turbine relevant pressures are still lacking. This work presents the first experimental demonstration of a new swirl-stabilized burner designed specifically for pure, uncracked ammonia, integrating key lessons from prior research: a rich primary zone with extended residence time, rapid secondary air mixing in a rich-quench-lean (RQL) configuration, and active liner heat loss management. The combustor, manufactured by additive manufacturing, was tested at pressures up to 10 bar and fuel input powers up to 117 kW in both non-premixed and piloted premixed configurations. Stable operation was achieved over a wide primary zone equivalence ratio range with ammonia slip below the 1 ppm detection limit. Both configurations exhibited an emissions optimum near ϕPZ=1.2, with NOx as low as 47 ppm and N2O around 1 ppm, and pressure benefits saturating near 8 bar. No HCN was detected during methane to ammonia fuel transition, supporting a practical start-up strategy. These results represent a critical step towards industrially relevant validation of direct ammonia-fired gas turbine combustion technology.