EU Sustainable Aviation Fuel Rules Favour Less Efficient Production Pathways

Research from Chalmers University of Technology warns that EU regulations designed to scale up sustainable aviation fuel may unintentionally raise production costs and energy use by favouring combustion-based pathways over more resource-efficient gasification routes. The study found the gasification pathway offers up to 46 per cent lower production cost and 30 per cent lower electricity demand than the alternatives currently favoured under EU rules.

Under EU rules introduced last year, aviation fuel suppliers must ensure at least 2 per cent of fuel at EU airports is sustainable aviation fuel (SAF), rising to at least 70 per cent by 2050. Half of that volume must come from renewable fuels of non-biological origin (RFNBO), a category covering synthetic fuels made from renewable hydrogen and captured carbon dioxide. The Chalmers researchers analysed three production pathways for synthetic methanol and found that EU regulations currently exclude the most efficient option — biomass gasification — from the RFNBO category because it directly uses biomass-derived carbon and energy.

Combustion-based pathways qualify for RFNBO classification when carbon dioxide is captured after biomass is burned for another purpose, such as in combined heat and power plants, even though they are less resource-efficient. The study found the gasification route performs significantly better on both cost and electricity demand, yet regulatory design disadvantages it. Researchers warned this risks increasing pressure on limited biomass resources while raising overall energy demand — the opposite of the RFNBO framework's stated goal of stimulating renewable electricity generation.

Henrik Thunman, professor of energy technology at Chalmers and co-author of the study, said current EU rules risk locking in less resource-efficient production methods by shaping both industry investment and research priorities. Lead author Johanna Beiron described it as surprising that the framework does not create stronger incentives for the most efficient technologies. Thunman called for better coordination between climate targets, resource efficiency and industrial feasibility, and said parts of the regulatory framework may require revision if the EU is to meet its long-term aviation decarbonisation goals. Ongoing geopolitical tensions have sharpened European focus on scaling domestic fossil-free fuel production.

Key figure — 46% lower production cost