Deutsche Aircraft, a manufacturer of regional aircraft, commissioned consultancy LBST ( Ludwig-Bölkow-Systemtechnik GmbH), a participating company of TÜV SÜD AG, to compile a comprehensive study comparing the economic and environmental performance of Liquefied Hydrogen (LH₂) and Power-to-Liquids (PtL) in aviation. The study is focused on domestic production of electricity-based Sustainable Aviation Fuels (e-SAF) in North America and Europe, while also taking North Africa and the Middle East into account as export regions.

The results complement concept studies at aircraft level with the fuel supply perspective of Sustainable Aviation Fuels.

Results of the study highlight that LH₂ has the potential to undercut PtL production costs if there are higher demands from airlines. Fuel production costs for PtL and LH₂ show similar orders of magnitude for small-scale applications such as regional airports.

While LH₂ can offer cost advantages over PtL at scale due to efficiency and liquefaction economics, it requires significant infrastructure investments and novel aircraft technologies. PtL, on the other hand, necessitates only marginal upgrades to existing infrastructure and aircraft systems.

According to the frameworks employed in the analysis, in terms of greenhouse gas emissions well-to-wake, PtL and LH₂ show comparable results. Moreover, the use of PtL and LH₂ demonstrate substantial benefits in terms of non-CO₂ effects according to current scientific understanding.

Process description for PtL and LH₂ pathways. Schmidt et al.

The study also emphasizes the importance of reducing certain aviation fuel constituents, such as aromatics and sulfur, to benefit both the climate and local air quality. For this reason, a dedicated fuel standard (“non-drop-in”) with zero aromatics is currently under development to minimize non-CO₂ effects and pollution.

Due to the long lifetime of aircraft, the massive scale-up of drop-in SAF is a crucial element to mitigate the climate impact of the existing fleet. At the same time, aircraft and engine OEMs must continue their efforts into hydrogen research. Further hydrogen technology maturation at the aircraft level will enable a complete end-to-end view when comparing Liquefied Hydrogen and Power-to-Liquids in terms of operating costs and specific primary energy demand.

The independent findings confirm our product strategy. In the short to mid-term, switching to 100% Sustainable Aviation Fuels, particularly Power-to-Liquids, is the best option to reduce environmental impact. Our D328eco will be compatible with 100% non-drop-in Sustainable Aviation Fuels, offering substantial reductions in pollution and climate impact as quickly as possible. When it comes to hydrogen, we continue our research and technology efforts, knowing that to operate commercial hydrogen aircraft, the industry must take a giant leap forward regarding technology maturity, infrastructure, regulations and economics.

—Dave Jackson, CEO at Deutsche Aircraft

Resources

• Schmidt, P.R., Weindorf, W., Failer, S., Astono, Y., Ullmann, A.: E-SAF: Techno-Economics of PtL and PtH2 – Focus North America and Europe; Ludwig-Bölkow-Systemtechnik GmbH – LBST, Ottobrunn/Munich, November 2023