In the framework of the FLEXnCONFU (FLEXibilize combined cycle power plant through power-to-x solutions using Non-CONventional FUels) European project, a dedicated test rig has been developed to enable the Turbec T100 mGT to operate with various ammonia-based fuel mixtures.
Four independent fuel lines, dedicated to H2, N2, natural gas, and NH3, were installed, allowing the preparation of mixtures ranging from NG–ammonia blends to combinations of hydrogen, nitrogen, and ammonia for simulating different levels of ammonia cracking. To accommodate these capabilities, the original T100 fuel system was disconnected and replaced with custom components.
All piping and fittings are made of AISI 316 stainless steel, with Teflon or EPDM seals suitable for ammonia operation. Moreover, instead of the onboard gas compressor, an external supply system provides natural gas at roughly 7 bar, while a gas mixer enables blending of ammonia and other gases. Hydrogen and nitrogen are delivered from 200-bar cylinders and regulated through pressure-reducing stages. Ammonia is stored in three 20-kg cylinders.
All fuel lines are equipped with Mass Flow Controllers, and a 12-m, 1-inch coil downstream of the mixer is included to decouple controller dynamics from the operation of the T100 pilot and main valves. A safety valve routes any over-pressure discharge to a water scrubber, exploiting ammonia’s high solubility. Finally, the original brass injection valves of the microturbine were replaced with stainless steel components to ensure compatibility with ammonia.
Moreover, operating the T100 with fuel blends having a lower lower heating value than natural gas requires a higher fuel-to-air ratio to ensure stable combustion. For this reason, the microturbine’s combustion chamber was replaced with a new design featuring enlarged dilution holes and increased fuel nozzle orifice sizes compared to the natural-gas version, thereby improving its suitability for low-LHV fuels.
Several experimental campaigns have been conducted successfully, achieving stable operation with NH₃/NG mixtures containing up to 50 %vol NH₃, as well as with NG/fully cracked ammonia mixtures containing up to 60 %vol cracked ammonia.
Related Publications
- Bellotti, D., Anfosso, C., Magistri, L. and Massardo, A.F., 2023, June. Partially Cracked Ammonia for Micro-Gas Turbine Application. In Turbo Expo: Power for Land, Sea, and Air (Vol. 86984, p. V005T06A032). American Society of Mechanical Engineers.
- Anfosso, C., Bellotti, D., Ferrari, M. L., & Magistri, L. (2025, June). Experimental Characterization of a Micro Gas Turbine Fueled by Ammonia-Natural Gas Blends. In Turbo Expo (Vol. 88803, p. V004T06A031). American Society of Mechanical Engineers.
Scientific Coordinator: Dr. Daria Bellotti, Prof. Loredana Magistri
Team Work: Chiara Anfosso, Mario Luigi Ferrari, Matteo Pascenti