Scaling sustainable aviation fuel through feedstock innovation

There are growing calls for the aviation industry to significantly reduce its carbon footprint but ensuring a secure supply of sustainable fuel alternatives requires the use of specialist analytical tools, explains George Gonzalez, Director, Global Energy and Chemical Markets Agilent Technologies
The aviation industry, which is currently responsible for around 2.5% of global CO₂ emissions, is under growing pressure to reduce its carbon footprint. Regulations are tightening and consumer expectations are growing; adopting sustainable practices and cutting emissions are no longer optional.
There are a number of ways to achieve these goals, including the use of next-gen airframe designs. But one of the most promising solutions is sustainable aviation fuel (SAF), a drop-in option capable of significantly reducing emissions while seamlessly integrating into existing aviation operations. However, scaling its production presents challenges that must be addressed to make SAF a viable global alternative to traditional jet fuel.

SAF’s potential and challenges

SAF’s ability to significantly reduce emissions is primarily driven by its use of biogenic feedstock – non-edible crops and biomass waste – which helps offset the carbon footprint. But there’s a downside; the use of crops as a raw material can destabilise land use, potentially affecting food supplies. This has impeded production and as a result, its penetration remains low – between 1-2% of global jet fuel consumption is SAF.
Fortunately, advances in testing methods and innovative production processes are already starting to help accelerate SAF’s commercial scalability. As the aviation industry looks to meet emission reduction targets, refining these technologies will be crucial to unlocking SAF’s full potential.

Innovation driving SAF production

Despite its emission reduction benefits, SAF’s high production costs – partly due to the current scale of production – means it is not yet a financially competitive option. The race to scale SAF also depends on significant feedstock innovation.
Beyond traditional crop-based options, non-food resources such as agricultural residues, fats and algae, are being explored to diversify SAF’s sources of raw materials. Algae-derived oils, for instance, could offer a sustainable and scalable source of SAF. However, these feedstocks remain in the experimental phase and scaling up production remains a challenge.
Alongside feedstock innovation, advances in production and testing technologies will be key. To ensure SAF meets the rigorous standards required for aviation use, the industry needs to focus on refining its production processes, improving feedstock options and ensuring compliance with global safety and regulatory frameworks.

Assuring purity

As SAF production ramps up, ensuring feedstock purity becomes paramount. Some, such as algae and agricultural residues, can contain metals such as phosphorous and potassium. Jet engine manufacturers are concerned about this as these metals can accumulate in engine turbines, potentially impairing performance. Quality control labs will therefore need a highly sensitive test method, one with a part per billion (PPB) limits, to help detect and eliminate impurities and guarantee fuel performance and safety.
Agilent is currently working with ASTM International on test methods for SAF under ASTM WK87272, the establishment of a test method for the determination of the elemental content in jet fuel. These will be based on the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), which is used due to its ability to perform multielement analyses, covering a broad range of concentrations as well as being robust and reliable.
For aviation fuel, one of the most recent innovations is comprehensive two-dimensional gas chromatography (GC) with flame ionisation detection (FID), a technique that can be used to analyse hydrocarbon types in jet fuels, including SAFs. It can provide greater capacity, resolution and detection limits than traditional GC-MS runs; it can also save time on sample preparation and instrumental analysis. In addition, the detection range of Agilent’s two-dimensional GC-FID technology makes it suitable for the exploration of non-food feedstocks, such as agricultural residues, algae and fats, expanding SAF’s raw material options.
In addition to testing for impurities, ensuring that SAF meets the aviation industry’s regulatory requirements is paramount. As SAF becomes more widespread, producers and regulators alike will need to ensure that the fuel consistently meets safety standards and environmental goals. This makes high-precision testing and monitoring essential for building trust in SAF’s long-term viability.

Lifecycle analysis for sustainability metrics

Along with purity testing, lifecycle analysis (LCA) is essential for evaluating the environmental impact of SAF. LCA tools help fuel producers assess SAF’s sustainability across its entire lifecycle, from feedstock extraction, transportation and processing to its impact on land and water usage and the potential for indirect effects on food security.
Without this information it will not be possible to ensure that SAF is delivering the optimum emission reductions, which could present issues around regulatory compliance. It will also be hard to judge if sustainable agricultural practices are being adopted for the production of SAF without a comprehensive approach to LCA.

The road ahead

For SAF to become a scalable and sustainable solution for the aviation industry, the feedstock pipeline must be diversified. A range of options will need to be explored, each with its own benefits and challenges. In the long term, some feedstocks may prove more beneficial than others; the key to success will be identifying those that can provide a steady supply of SAF while minimising environmental and economic costs.
As commercial viability increases, high-quality, precision feedstock testing will play a pivotal role in unlocking new sources of raw materials, reducing operational costs and proving SAF’s potential to regulators and operators. By ensuring compliance with safety and regulatory standards, testing will help demonstrate that SAF is the best fuel option for achieving a low-emission aviation industry.
Agilent is already working to unlock this potential and is well positioned to help aircraft operators across the globe attain their emission reduction goals, effectively, safely and efficiently.