Particle emissions, Air Quality and Climate Impact related to Fuel Composition and Engine Cycle

Among aviation’s non-CO2 impacts, the largest radiative forcing value is attributed to contrail cirrus. Recent tests have revealed an opportunity for lowering soot particles emissions and ice crystals -which play a pivotal role in contrail properties- through the use of SAF. However, substantial disparities remain among those test campaigns, involving a large variety of fuels, engine types and combustors. It is therefore not straightforward to compare and reconcile results.In this context, PACIFIC aims to bridge the gap: the project will test an unprecedented set of fuels from lab up to engine/aircraft level with a similarity of hardware and combustion parameters. It will translate the results into modelling efforts, to better correlate: (i) soot formation, based on an improved Yield Soot Index database and prediction model; (ii) particle emissions, depending on fuel composition for the whole engine thrust range via an upgraded ground-to-flight correlation methodology; (iii) the ice forming potential of engine emissions, using advanced measurement methods on ground; (iv) the non-CO2 emission mitigation potential, through the impact assessment of fuel composition and engine cycle on contrail properties and radiative forcing, and longer-term climate impacts (including CO2 emissions fuel production). This will allow to consolidate the cost-benefit assessment of various fuel options and provide valuable inputs to potential future fuel-related measures.By doing so, PACIFIC will pave the way for future fuel specifications minimizing the climate and local air quality impacts, and will provide important inputs to future modelling and testing work.PACIFIC leverages on 11 partners from 4 countries, bringing together a unique combination of engine/aircraft manufacturers, fuel producers, research and academic expertise at the forefront of sustainable aviation, collectively driving advancements to help strengthening the European aeronautics' leadership position.