Hi-EFECTS results presented at Mediterranean Combustion Symposium 2025

The Hi-EFECTS project was representedinternationally at the 13th Mediterranean Combustion Symposium, held on June1–5, 2025. Margherita Miccio from Lund University presented her research oncombustion and emission characteristics in a two-stroke direct-injectionammonia/diesel engine.

The results show that the dual-fuel engine produceslower NOx emissions per kilogram of injected fuel compared to the diesel-onlyengine, primarily due to de-NOx reactions such as NO₂ + NH₂ → N₂O +H₂O. CO emissions are also significantly reduced becauseof the higher combustion temperatures in the dual-fuel configuration. However,total greenhouse gas (GHG) emissions increase in the dual-fuel engine due toelevated N₂O emissions, which have a much higher global warmingpotential (GWP) than CO₂. These findings highlight the need for furtherresearch into N₂O emission mechanisms in ammonia engines, as well asoptimization of injection strategies and engine configurations to achievehigher combustion efficiency with lower N₂Oemissions.