eSAF: why major industrials are betting on synthetic aviation fuel now

Why biofuels alone can't scale — and eSAF can

First-generation sustainable aviation fuels, made from used cooking oil, agricultural residues or forestry waste, face a structural ceiling: these feedstocks exist in finite quantities. As demand for SAF rises under Europe's ReFuelEU Aviation targets, competition for these limited biomass streams is already intensifying.

Against this backdrop, synthetic fuels — eSAF, or electronic Sustainable Aviation Fuels — are gaining traction with aerospace and energy players. Unlike biofuels, they depend on neither biomass nor agricultural waste: their raw inputs are water, renewable electricity and captured CO2. Production potential is therefore, in theory, nearly unlimited, provided the electricity and industrial capacity exist to support it.

eSAF won't replace biofuels overnight, but it is the only pathway able to absorb long-term growth in demand for sustainable aviation fuel.

Power-to-Liquid and green hydrogen: the technology shift

eSAF production relies on Power-to-Liquid (PtL) technology, which converts renewable electricity into liquid fuel in two main steps. The first is producing green hydrogen through water electrolysis, powered by renewable sources such as wind, solar or hydro. This step is the linchpin of the whole chain: without decarbonised electricity available at scale and at a manageable cost, PtL cannot be deployed industrially.

The second step combines that green hydrogen with captured CO2 — sourced either directly from the air or from industrial sites — to synthesise a substitute kerosene. The principle is simple on paper: the carbon used to make the fuel is the same carbon released when it is burned, bringing the fuel's life cycle close to genuine carbon neutrality. This differs fundamentally from the biofuel approach, which relies on converting existing organic matter.

• Water electrolysis powered by renewable electricity to produce green hydrogen
• Capture of atmospheric or industrial CO2 as the carbon source
• Chemical synthesis combining hydrogen and CO2 into a synthetic kerosene
• A near-neutral carbon cycle, independent of biomass resources

The Dunkirk project: an alliance of industrial heavyweights

The partnership between Technip Energies, Airbus and Safran on an industrial project in Dunkirk illustrates this dynamic concretely. Technip Energies brings engineering and process-technology expertise, while Airbus and Safran — an airframer and an engine manufacturer respectively — contribute deep knowledge of fuel qualification and certification requirements. This convergence of energy and aerospace know-how is precisely what has been missing to move eSAF from pilot scale to industrial scale.

The choice of Dunkirk is no accident: the hub offers access to local renewable capacity and a dense industrial ecosystem, two conditions needed for competitive eSAF production. This project goes beyond simply meeting a regulatory obligation; it reflects a deliberate move to secure, upstream, the future supply chain for decarbonised aviation. The industrials structuring these alliances today are positioning themselves to capture value in a market that is still emerging.

For aviation fuel buyers, this alliance sends a clear signal: eSAF will not remain a lab-scale project. Industrial capacity is being built by players able to secure hydrogen production, engine design and integration with existing fleets all at once.

How Heeding supports the shift to synthetic fuels

As eSAF starts to shape the market, aviation fuel buyers face a new challenge: identifying producers, assessing available volumes and comparing technologies that are not yet standardised. Heeding, a marketplace and purchasing platform for sustainable fuels, gives access to offers from multiple producers and distributors, without ever selling fuel in its own name.