Policy has moved faster than plant construction. Mandated blending percentages, revenue certainty mechanisms and sub-targets for synthetic fuels give the sector something it lacked for a decade: a demand curve that does not depend on voluntary purchasing. What it does not give the sector is molecules.
Where the volumes are meant to come from
Today the overwhelming majority of certified sustainable aviation fuel comes from hydroprocessed esters and fatty acids. That pathway works, but it competes for a waste oils and fats pool that is already tight and already spoken for by road and marine demand. Scaling it alone does not close the gap between mandate and supply.
- Waste oils and fats: proven, commercially deployed, feedstock constrained
- Alcohol-to-jet: scaling, dependent on low-carbon ethanol supply
- Power-to-liquid: long-dated, capital and renewable electricity intensive
- Lignocellulosic routes: the largest feedstock pool, the least industrialised
Agricultural and forestry residues are the only pool large enough to serve aviation at mandate scale without displacing food or land. The reason they are underused is not availability. It is that converting them produces an intermediate most refineries currently cannot accept.
Mandates create demand for a fuel. They do not create the conditioning step that lets residue-derived carbon reach a refinery gate.
Why the intermediate matters more than the mandate
A policy target expressed in percentage blends is ultimately a question about intermediates. If a stabilised, specification-compliant biogenic co-feed can be delivered to existing hydroprocessing and FCC assets, then a large share of the required capacity already exists and needs no greenfield refinery. If it cannot, every litre depends on new build.
That is why our work sits at the conditioning layer rather than at the fuel layer. The licensable unit is the step between pyrolysis and the refinery, and it is the step that determines whether the residue pathway contributes to the mandate this decade or the next.
We track UK and EU policy closely and take part in industry forums on deployment and certification. If you are working on the policy or offtake side and want a technical view on feedstock realism, get in touch.
