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While the HEFA pathway will dominate SAF production over the next 10 years, other production pathways will also see significant scale-up. Image Credit: IDTechEx

The transportation sector needs to decarbonize globally by 2050 to avoid the worst impacts of climate change. For aviation, this will require low-carbon fuels in large quantities as explored in IDTechEx’s “Sustainable Biofuels & E-Fuels Market 2026-2036” report. However, the climate crisis is not the only motivation to scale-up SAF (sustainable aviation fuel) production. Rising oil prices prove that the disadvantages of fossil fuels extend beyond their negative environmental impact. Therefore, sustainable aviation fuel should also be viewed through the lens of empowering energy security.

Is HEFA the Answer?

HEFA (Hydroprocessed Esters and Fatty Acids) fuel is the leading SAF as of 2026. The production process uses waste oils, such as used cooking oils, as the feedstock instead of fossil fuels. This offers fuel with a much lower carbon footprint and an alternative supply chain.

The current fuel crisis may have reawakened interest in the HEFA pathway, but the bigger picture remains complicated. While the price gap between conventional jet fuel and HEFA-SAF has shrunk following the impact of the Iran war, HEFA fuel is still more expensive. Moreover, the HEFA-SAF supply chain has its own complexities, with a significant amount of Europe’s used cooking oil supply needing to be imported.

It is clear that HEFA-SAF is not an immediate solution to global oil woes. However, longer-term visions for global aviation include a fuel supply that can be produced locally and with a lower carbon footprint. The HEFA production pathway has a leading role to play, although scale-up will be somewhat constrained by the availability of feedstocks.

Other SAF Pathways have Greater Feedstock Flexibility

Other pathways to sustainable aviation fuel use bio-based feedstocks that can be sourced locally. One example is the alcohol-to-jet pathway, which will be especially attractive for regions with significant bioethanol production already (such as the US and Brazil). Gasification of biomass, followed by mature Fischer-Tropsch synthesis, also holds promise. This is the pathway planned for Altalto’s UK-based future SAF facility, designed to produce 30 million liters of jet fuel by gasifying municipal solid waste. This plant will use Velocys’ innovation Fischer-Tropsch reactor design.

Although production of jet fuel via the alcohol-to-jet or gasification+Fischer-Tropsch pathways is more costly than the HEFA pathway, the greater availability of feedstocks for these fuels means they will be needed in large quantities as the SAF space matures. In industry, this is described as going “beyond the HEFA tipping point”. According to IDTechEx’s “Sustainable Biofuels & E-Fuels Market 2026-2036”, the sustainable fuel landscape will need to become much more diverse by 2036.

e-SAF

However, while biomass is locally available, it can still have constraints (such as competition with agricultural land). Therefore, when it comes to feedstock flexibility, e-SAF is the ultimate winner. This fuel is produced by reacting captured CO2 with green hydrogen (generated from water using renewable energy).

Theoretically, the abundance of water, CO2, and renewable power sources such as wind and solar can provide limitless potential for scale-up. In reality, high energy costs and low availability of CCUS infrastructure means this CO2 utilization pathway remains a very expensive way to produce jet fuel. Nevertheless, regulatory roadmaps to cover the green premium have already been set out in the EU.

What About Gas?

While high oil prices are currently splashed across headlines, gas prices are also vulnerable to geopolitical uncertainty. This was demonstrated a few years ago when European gas prices skyrocketed following Russia’s invasion of Ukraine. Crucially, there are also sustainable alternatives to gas which could further boost energy security. These include biomethane (typically produced from biogas upgrading via gas separation membranes) and e-methane.

Outlook

Sustainable fuel production is not just good for the environment. It also decouples oil and gas prices from geopolitical instability. The potential for these low-carbon fuels is vast and fuel supply can be localized, offering a long-term vision for energy security. While sustainable fuels are expensive, technology scale-up and regulatory support offer a clear business case for the future.

Source: IDTechEx