Sustainable aviation fuels have gained prominence because aviation accounts for approximately 2% of global CO₂ emissions. While this percentage may seem modest, it becomes significant given the projected rapid growth in energy demand in the coming decades—especially as air transport tends to replace other modes on many routes. Thus, reducing the carbon footprint associated with aviation fuels has become a global priority.
It is in this context that the replacement of fossil kerosene (QAV) with sustainable aviation fuels (SAF) is making concrete progress. This solution is already in use and can reduce emissions by between 50% and 80% throughout its entire life cycle, currently being considered the most effective alternative for decarbonizing the aviation sector.
Regulatory frameworks
The production and use of SAF is already an international reality. The International Civil Aviation Organization (ICAO) and the European Union have established targets for the gradual decarbonization of aviation fuels, requiring the addition of SAF and annual performance targets until 2035.
Although there is still no global agreement that equalizes the requirements for SAF participation in the market, several countries such as Norway, Indonesia, Sweden, the United Kingdom, France, Spain, and Mexico have taken the lead and established their own mandates. Brazil also sees the issue not only as an important environmental concern but also as an opportunity to further develop the biofuel market. In 2024, the so-called Future Fuel Law was approved, which, among other initiatives, creates the ProBioQAV program to encourage the production and use of SAF in the country, with a phased mandate for adding SAF to aviation kerosene, reaching up to 10% by 2037.
How is SAF produced?
Currently, there are 5 certified SAF production routes in accordance with the ASTM D7566 standard.
- Hydroprocessing of esters and fatty acids (HEFA): It uses vegetable oils, animal fats, and waste oils. It's a more mature and commercially available technology, with lower costs, but limited by the availability of raw materials.
- Fischer–Tropsch Synthesis (FT-SPK and FT-SPK/A): It converts biomass and waste through gasification into synthesis gas, followed by Fischer-Tropsch synthesis. The feedstock is flexible, and it offers high GHG reduction, but the process is expensive and requires rigorous purification of the synthesis gas. The FT-SPK/A variant adds aromatics to the synthesis, as their content increases the ability to be added to jet fuel without compromising the quality of some fuel properties.
- Alcohol-to-kerosene (ATJ) process: Converts ethanol/isobutanol into aviation fuel through dehydration, oligomerization, and hydrogenation. An emerging route with moderate costs but very high potential.
- Hydroprocessing of fermented sugars (HFS-SIP): It produces farnesane from the fermentation of sugars. It still has a high cost and limited mixing capacity with jet fuel.
In addition to these, there are emerging production technologies, such as pyrolysis, hydrothermal liquefaction, and aerobic fermentation, but these are still in the development and optimization phase.
In any case, transforming waste and low-value-added products into SAF (Sustainable Agricultural Production) is becoming big business, and technology has kept pace with this environmental need.
Quality and confidence
Unlike a car, where refueling with poor-quality fuel can – in extreme cases – only result in the vehicle ceasing to function, an airplane cannot rely on a repair shop or tow truck at an altitude of 10.000 meters!
Therefore, the quality specification for jet fuel is extensive, with each analysis performed relating to some important property. For example, properties such as freezing point and viscosity are related to the ability to flow at low temperatures, while thermal oxidation stability is related to the fuel's behavior under extreme temperature and pressure conditions in contact with the turbine.
According to a resolution from the National Agency of Petroleum, Natural Gas and Biofuels (ANP) No. 856/2021There are over 40 quality parameters that need to be analyzed and within specification for jet fuel to be marketed. Each measured property has associated methods, instruments, and accessories that every industrial and fuel quality laboratory needs to possess to enable and certify the production of jet fuel and fuel concentrate.
How can Alutal help in monitoring the quality of sustainable aviation fuels?
Within its line of laboratory products, Alutal can offer various solutions for the analysis of SAF and QAV:
VD10 – Video-controlled automated distiller
Innovative and unique equipment on the market, the atmospheric distiller from AD Systems It allows the analysis of QAV, SAF samples and their mixtures, without the need for tedious method programming, due to its revolutionary video-controlled heating algorithm.
TO10 – oxidation stability
This robust analyzer, more tolerant of alternative aviation fuel samples such as SAF, from AD Systems, performs analyses according to ASTM D3241 standards. It is very practical to set up the test, as it requires no tools, and is fully automated in its completion.
DR10 – oxidation deposit evaluator
Used in conjunction with the TO10 analyzer, the AD Systems heater tube evaluator brings objectivity and traceability to oxidation stability analysis, reporting results directly and automatically in accordance with ASTM D3241 (in millimeters of deposit) without the need for constant recalibration.
Approved heater tubes
Recently approved by ASTM, AD Systems test tubes are rigorously controlled and certified in their metallurgy and dimensions, and can be used in any equipment that conforms to ASTM D 3241.
SP20 – Automatic soot point analyzer
This equipment is unique on the market, and it automates the process of analyzing and reporting results for the soot point of jet fuel and aerosol spray, according to ASTM D 1322 standards. An exclusive patent of AD Systems, this instrument accelerates and eliminates the subjectivity of interpreting results from the manual method.
MiniFlash FP – flash point
This equipment from Grabner Instruments It utilizes the continuously closed cup method described by ASTM D7094, which is faster, more accurate, and safer than the specification method (Pensky-Martens method ASTM D93). Furthermore, this instrument exhibits proven correlation*, without bias, and better repeatability than the Pensky-Martens method.
MiniScan IR Pro – FTIR fuel analyzer
Used for rapid in-process and laboratory analysis, this equipment from Grabner Instruments allows for the evaluation of various properties of jet fuel, ethanol, diesel, gasoline, and ethanol, acting as a guardian of fuel production, blending, and storage processes.
DS7800 – Digital density meter
Using low sample volumes, the densimeters of Kruss Optronic They meet the ASTM D4052 standard, offering excellent cost-effectiveness. They can be coupled to automatic samplers, ideal for laboratories with a high demand for analyzing various products.
Alutal wants to be your partner in the development of sustainable fuels. Contact us to schedule a visit or a presentation of our products!
* In accordance with an interlaboratory study conducted by ASTM, see note 7 of the ASTM D7094 standard – Standard Test Method for Flash Point by Modified Continuously Closed Cup (MCCCFP) Tester.
References
ASTM D7566 – Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons. West Conshohocken, PA: ASTM International.
ANP Resolution No. 856, of October 22, 2021. Establishes the specifications for JET A and JET A-1 aviation kerosene, alternative aviation kerosenes, and aviation kerosene C (JET C), as well as the quality control obligations to be met by economic agents that market these products in the national territory. Brasília, 2021.
Law No. 14.993, of October 8, 2024. Provides for the promotion of low-carbon sustainable mobility and establishes the National Sustainable Aviation Fuel Program (ProBioQAV). Official Gazette of the Union, section 1, Brasília, DF, pp. 1–26, 2024.
ZHANG, Libing; BUTLER, Terri L.; Yang, Bin. Recent Trends, Opportunities and Challenges of Sustainable Aviation Fuel. in: VERTÈS, AA; QURESHI, N.; BLASCHEK, HP; YUKAWA, H. (eds.). Green Energy to Sustainability: Strategies for Global Industries. Hoboken, NJ: John Wiley & Sons, 2020. p. 85-110
MUSSA, Nur-Sultan; KAINAUBEK, Toshtay; CAPRON, Mickael. Catalytic Applications in the Production of Hydrotreated Vegetable Oil (HVO) as a Renewable Fuel: A Review. Catalysts, vol. 14, no. 452, 2024.
NG, Kok Siew; FAROOQ, Danial; YANG, Aidong. Global biorenewable development strategies for sustainable aviation fuel production. Renewable and Sustainable Energy Reviews, vol. 150, p. 111502, 2021.
