European Union rules on sustainable aviation fuels could make said fuels ‘unnecessarily expensive and energy-intensive’, a new study by researchers at Chalmers University of Technology has suggested.
According to the study, which explored different pathways for producing synthetic methanol (which in turn can be converted into sustainable aviation fuel), current regulations under the bloc’s ReFuelEU Aviation framework favour production methods based on biomass combustion rather than gasification, despite the latter being more energy and cost efficient.
Aviation fuel
According to EU rules introduced last year, aviation fuel sold at EU airports must include a minimum blend of 2% sustainable aviation fuel. This ratio is set to increase to at least 70% by 2050, with half of that fuel required to come from a category known as RFNBO, or renewable fuel of non-biological origin.
According to the researchers, the current regulatory framework excludes a large share of fuels produced through biomass gasification from qualifying as RFNBOs, because the process uses carbon and energy directly from biomass.
“Regulations influence not only industry’s investments in technology, but also which research and development priorities are pursued,” commented Henrik Thunman, professor of Energy Technology at Chalmers and co-author of the study. “Instead of driving innovation towards the most efficient solutions, we risk locking ourselves into less resource-efficient production methods.”
Production pathways
The study compared three production pathways for synthetic methanol using biomass from forestry residues. Two methods relied on biomass combustion with carbon capture, while the third used biomass gasification to create synthesis gas directly for fuel production.
According to the findings, the gasification pathway reduced production costs by up to 46% and electricity demand by around 30% compared with combustion-based alternatives, as well as achieving greater energy efficiency.
‘Most efficient alternatives’
“It is surprising that EU rules do not provide clearer incentives for the most efficient alternatives,” added Johanna Beiron, researcher in Physical Resource Theory at Chalmers and lead author of the article.
“The current regulatory framework risks causing lock-in to combustion-based energy systems, even though technically mature processes already exist that would provide both lower energy use and lower cost – such as gasification and electrification of district heating.”
As the study found, biomass gasification produced methanol at an estimated cost of €820 per tonne, compared with €1,055 per tonne for combustion with carbon capture and €1,495 per tonne for combustion combined with energy production. Read more here.
