Sustainable Aviation Fuel helps to decarbonise aviation by creating a closed-loop carbon cycle using captured or waste-derived CO₂.
What is Sustainable Aviation Fuel?
Sustainable Aviation Fuel (SAF) is jet fuel made from non-fossil carbon sources, traditionally waste oils, agricultural residues or municipal waste. Alternatively, Sustainable Aviation Fuel can be made from captured carbon dioxide (CO₂) combined with green hydrogen to produce an eFuel called electro-Sustainable Aviation Fuel, or eSAF.
Direct Air Capture and eSAF
Direct Air Capture technology is well suited to provide the CO₂ feedstock for the manufacture of eSAF. Find out why in more detail: Why Direct Air Capture is Critical to Sustainable Aviation Fuel Production
Sustainable Aviation Fuels are called ‘drop-in’ fuels as they can be blended with conventional jet fuel and used with existing aeroplane engines without any need for modifications, meaning the aviation industry can reduce its carbon footprint without the need to redesign the plane engines or infrastructure. Depending on the feedstock and production method used, SAF can achieve emissions reductions of up to 80% (iata.org).
Why do we Need SAF?
Aviation is responsible for about 950 million tonnes of CO₂ emissions per annum globally, which accounts for about 2.5% of global CO₂ emissions (iea.org), a figure that is predicted to rise unless effective interventions are made. Unlike road transport, which can relatively easily transition to electric power, aircraft require energy-dense fuel to cover the vast distances they fly. SAF offers a solution that can immediately and dramatically reduce the carbon emissions of flights while using existing engine technology and SAF usage can be scaled up as technology improves and costs decrease.
In 2025, around 2 million tonnes of SAF was produced, which is only 0.6% of the total jet fuel consumption. To put this in perspective, the aim is to produce 500 million tonnes by 2050 if SAF is to have an impact on aviation carbon emissions. According to IATA, achieving this will require the “development of strong policy frameworks that give certainty, a coherent regulatory environment, industrial partnerships, global feedstock access, infrastructure investment, and effective technology deployment.” (iata.org)
Types of Sustainable Aviation Fuel
ELECTRO SUSTAINABLE AVIATION FUEL (eSAF)
What is the difference between SAF and e-SAF?
While SAF includes biofuels derived from, for example, biomass, vegetable oils and waste fats, e-SAF is a specific type of SAF made using green energy to produce hydrogen and captured CO₂ which are synthesised into aviation fuel. In other words, eSAF is a type of Power-to-Liquid (PtL) eFuel (electroFuel).
HEFA (Hydrotreated Esters and Fatty Acids)/ Biofuels
HEFA is a process used to produce Sustainable Aviation Fuel by refining vegetable oils, animal fats, or other renewable feedstocks into high-quality jet fuel
ALCOHOL TO JET
The alcohol-to-jet (ATJ) process converts alcohols like ethanol or butanol into jet fuel through dehydration, oligomerisation, and hydrogenation, producing a sustainable alternative to conventional aviation fuels.
NEG8 Carbon Partners in UK eSAF Project
NEG8 Carbon, has signed a contract for Phase 1 of a major project in the UK to develop large-scale Sustainable Aviation Fuel (eSAF) production using a near zero carbon nuclear energy source. NEG8 Carbon will provide the CO₂ feedstock needed to make eSAF as part of the Equilibrion project, Eq.flight. The project is funded by the UK government’s Advanced Fuels Fund.
For more: Lift Off for NEG8 Carbon in Sustainable Aviation Fuel
Sustainable Aviation Fuel FAQs
How is Sustainable Aviation Fuel made?
SAF can be derived from sustainable feedstocks such as used cooking oil, agricultural and municipal waste, or alternatively, green hydrogen and captured CO₂. These materials are refined to create a fuel that works in aeroplane engines in the same way as conventional jet fuel.
Learn more: How is Sustainable Aviation Fuel Made?
How does SAF decarbonise aviation?
SAF can help aviation reach net-zero by creating a closed loop of carbon emissions<> carbon capture in aviation.
Learn more: How does SAF Reduce Emissions?
How does SAF differ from traditional jet fuel?
SAF performs virtually identically to conventional jet fuel, it meets the same quality standards and is compatible with existing aircraft engines. However, when contrasted with traditional jet fuel, SAF provides notable environmental advantages.
Learn more: SAF vs Jet Fuel
Why is Direct Air Capture critical to Sustainable Aviation Fuel production?
Direct Air Capture (DAC) provides a reliable and sustainable source of CO₂ as a feedstock for eSAF production.
Learn more: Why Direct Air Capture is Critical to Sustainable Aviation Fuel Production
What are the regulations driving SAF implementation?
In the EU and globally, governments are implementing regulations that enforce the adoption of SAF in the drive to decarbonise aviation.
Learn more: SAF Regulations
Final Thoughts
While challenges remain, the potential benefits of SAF make it central to the aviation industry’s sustainability strategy. As regulations evolve and production ramps up, we can expect to see SAF playing an increasingly important role in our journey towards cleaner skies.
For more:
- What is eFuel?
- What is eMethanol?
- Hard to Abate Industries and the Decarbonisation Challenge
- Sustainable Data Centres with Direct Air Capture
- Decarbonising Construction by Storing CO2 in Concrete