Paving the path toward 100 % renewable fuels in aviation

While initially bio-based fuels were in the focus of our research, their limitations led to a shift in focus toward renewable fuels of non-biological origin. For a comparison of a wide variety of fuel technologies, a multiple-criteria assessment framework was developed with environmental impact and production cost as key indicators, among others.

The scale of the future energy demand, fuel production potentials, the technological viability of fuel pathways, production capacity ramp-up, life-cycle quality, and various economic considerations were the subject of many assessments. Investigations of biofuel pathways pointed to a severe limitation of sustainable feedstock for first-generation biofuel production. Technologies for the conversion of advanced biogenic feedstock can add significant fuel production potentials, but require continued research and development efforts to achieve commercial readiness.

Early on, Bauhaus Luftfahrt researched the potential of non-biogenic sustainable solutions, such as “green” hydrogen, sunlight-to-liquid or power-to liquid technologies. Geo-referenced analyses of fuel production potentials showed their scalability beyond the future demand. For drop-in fuel production, direct air capture of CO₂ needs to be developed due to the limited availability of biogenic carbon sources. Renewable electricity from photovoltaic and wind power have great potential for use in aviation primarily via hydrogen in liquid form or in drop-in capable hydrocarbon fuels. In which form hydrogen will eventually be used best in aviation is subject of current research and will be linked to economic considerations and to the climate impact as a figure of merit.