Climate Impact Reduction Potentials of Synthetic Kerosene and Green Hydrogen Powered Mid-Range Aircraft Concepts

One of aviation's major challenges for the upcoming decades is the reduction in its climate impact. As synthetic kerosene and green hydrogen are two promising candidates, their potentials in decreasing the climate impact is investigated for the mid-range segment. Evolutionary advancements for 2040 are applied, first with an conventional and second with an advanced low-NOx and low-soot combustion chamber. Experts and methods from all relevant disciplines are involved, starting from combustion, turbofan engine, overall aircraft design, fleet level, and climate impact assessment, allowing a sophisticated and holistic evaluation. The main takeaway is that both energy carriers have the potential to strongly reduce the fleet level climate impact by more than 75% compared with the reference. Applying a flight-level constraint of 290 and a cruise Mach number of 0.75, causing 5% higher average Direct Operating Costs (DOC), the reduction is even more than 85%. The main levers to achieve this are the advanced combustion chamber, an efficient contrail avoidance strategy, in this case a pure flight-level constraint, and the use of CO2 neutral energy carrier, in a descending priority order. Although vehicle efficiency gains only lead to rather low impact reduction, they are very important to compensate the increased costs of synthetic fuels or green hydrogen.