Hydrogen from ethanol reforming mapped as aviation fuel-cell pathway

by Simon Mansfield
Sydney, Australia (SPX) Dec 19, 2025

The global effort to cut aviation emissions has put hydrogen at the center of long-term propulsion plans for aircraft, with fuel cells emerging as a leading alternative to combustion engines because they provide electric propulsion with no direct carbon dioxide output and high conversion efficiency. A detailed quantitative study by researchers at the University of Sao Paulo, working with the Research Centre for Greenhouse Gas Innovation, compares conventional thermal reforming with electrochemical routes to map realistic transition paths toward hydrogen-based Sustainable Aviation Fuels.

The paper identifies electrochemical reforming as the route that best aligns with aviation's operational and environmental demands when set against steam methane reforming, which still supplies about 96 percent of global hydrogen and remains cost-competitive but has high emissions. Steam methane reforming runs at temperatures of roughly 700 to 1000 degrees Celsius and releases about 9 to 12 kilograms of carbon dioxide per kilogram of hydrogen, which constrains its role in deep decarbonization of flight.

Electrochemical reforming instead generates hydrogen at temperatures of about 50 to 90 degrees Celsius, lowering process complexity and energy losses compared with high-temperature systems. The authors note that these mild conditions support modular, decentralized installations that can be located close to where hydrogen is consumed.

For aviation, the analysis points to hydrogen storage as a key obstacle, especially in liquid form, which requires cryogenic temperatures below 20 kelvin and tanks with volumes up to four times larger than current jet-fuel systems. These requirements add structural, safety and cost burdens for aircraft and airport operations, limiting the practicality of large-scale liquid hydrogen use in commercial fleets.

Electrochemical reforming addresses this by producing hydrogen in situ from liquid alcohols such as bioethanol, either onboard aircraft or at airports, rather than storing hydrogen as a separate cryogenic fluid. Ethanol is liquid at ambient temperature and pressure and is compatible with existing kerosene logistics and infrastructure, which the study notes can reduce retrofit work and lessen the safety and volume penalties associated with liquid hydrogen tanks.

In its economic section, the study sets explicit conditions for electrochemical reforming to match the cost of steam methane reforming while lowering lifecycle emissions. Sensitivity analysis shows that parity is possible if electrocatalyst expenses fall by about 60 percent or if renewable electricity prices drop below 0.03 US dollars per kilowatt-hour, providing measurable development targets for technology providers and policymakers.

With these thresholds and its fit with existing fuel-handling systems, the authors conclude that electrochemical reforming can scale as a low-carbon hydrogen supply for aviation. They link this production pathway to hybrid-electric aircraft designs that use liquid bioethanol as the primary energy carrier, which is converted into hydrogen and then electricity during operation.

Coupling electrochemical reformers with fuel cells would allow aircraft to draw electrical power directly from ethanol in flight, avoiding the mass and safety issues tied to cryogenic hydrogen storage while maintaining the energy density needed for longer ranges. The analysis argues that such configurations can support strategies to reduce carbon dioxide emissions from air transport without abandoning existing liquid-fuel infrastructure.

By outlining thermodynamic limits, storage constraints and cost benchmarks, the work provides an engineering framework to guide regulatory choices and industrial investment in hydrogen aviation. The authors position electrochemical reforming of renewable ethanol as a route that can inform future spending on sustainable aviation fuels and the design of aircraft and airport systems capable of operating with ethanol-derived hydrogen.

Research Report:A Comparative Analysis of Conventional Thermal and Electrochemical Reforming Pathways for Hydrogen Production Towards Sustainable Aviation Fuels (SAF)