Sustainable Aviation Fuel (SAF) Glossary: Common Acronyms Explained

The Sustainable Aviation Fuel (SAF) industry is a dynamic and rapidly evolving sector, driven by innovative technologies and global efforts to reduce aviation’s impact on the environment, while also building a new energy industry and revitalizing rural communities across the world. Like many specialized industries, SAF comes with its own set of acronyms and terminology that can feel overwhelming for newcomers or even seasoned professionals trying to stay up-to-date. 

To help you navigate this complex landscape, we’ve created a comprehensive guide to the most commonly used acronyms in the SAF industry. Whether you’re exploring pathways like ATJ (Alcohol-to-Jet) or HEFA (Hydroprocessed Esters and Fatty Acids), learning about lifecycle analysis tools like GREET, or understanding the role of organizations like ASTM in fuel certification, this list is designed to demystify the language of SAF and make it more accessible. 

1. ATJ (Alcohol-to-Jet): A process of converting alcohols, like ethanol, into jet fuel, which is a recognized pathway for producing sustainable aviation fuel (SAF). 
2. ASTM (American Society for Testing and Materials): A standards organization that certifies SAF for use in commercial aviation by ensuring it meets safety and performance standards. 
3. BETO (The Bioenergy Technologies Office): Office part of the U.S. Department of Energy that supports research and development of biofuels like SAF. 
4. CAPEX (Capital Expenditure): The upfront investment required for building, upgrading, or maintaining infrastructure and equipment, such as SAF production facilities. 
5. CCU (Carbon Capture and Utilization): A process that captures carbon dioxide emissions and converts them into useful products, including SAF. 
6. CI (Carbon Intensity): A measure of the greenhouse gas emissions per unit of energy produced, used to assess the environmental impact of SAF compared to conventional fuels. 
7. CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation): An ICAO initiative that promotes the use of SAF to help the aviation industry reduce carbon emissions and meet international offsetting goals. 
8. DAC (Direct Air Capture): A technology that captures carbon dioxide from the atmosphere, which can be combined with other elements to create synthetic SAF. 
9. eFuel (Electrofuels): Synthetic fuels produced using renewable electricity, water, and CO2, considered a future sustainable option in the SAF industry. 
10. E2E (Ethanol-to-Ethylene): A process that converts ethanol into ethylene, a key building block for producing plastics, chemicals, and potentially SAF. 
11. E2J (Ethylene-to-Jet): A technology process that converts ethylene, a hydrocarbon derived from sources like ethanol, into sustainable jet fuel. 
12. E‑to-SAF (Ethanol-to-SAF): A technology pathway that converts ethanol into Sustainable Aviation Fuel. 
13. ESG (Environmental, Social, and Governance): Criteria used by companies and investors to evaluate sustainability practices, including the production and use of SAF. 
14. FS (Feasibility Study): An assessment conducted to evaluate the viability of SAF production projects, including technical, economic, and environmental factors. 
15. FEED (Front-End Engineering Design): The initial phase of project planning for SAF production facilities, involving detailed design and engineering work to define project scope. 
16. FT (Fischer-Tropsch): A process that converts biomass or waste gases into synthetic fuels, including SAF, making it a key technology for sustainable fuel production. 
17. FOGs (Fats, Oils, and Greases): A category of waste materials used as feedstocks in the production of HEFA-based SAF. 
18. GHG (Greenhouse Gas): Gases like CO2 that trap heat in the atmosphere; reducing GHG emissions is a key benefit of SAF as compared to traditional jet fuels. 
19. GREET (Greenhouse gases, Regulated Emissions, and Energy use in Technologies): A model developed by Argonne National Laboratory used to evaluate the lifecycle environmental impacts of SAF production. 
20. HEFA (Hydroprocessed Esters and Fatty Acids): A process used to produce SAF from lipids such as vegetable oils, animal fats, or used cooking oils. 
21. HTL (Hydrothermal Liquefaction): A technology that converts wet biomass into liquid fuels, including SAF, by using heat and pressure. 
22. IATA (International Air Transport Association): A global organization representing airlines that promotes the adoption of SAF to help reduce the aviation industry’s carbon footprint. 
23. ICAO (International Civil Aviation Organization): A U.N. specialized agency that sets global aviation standards and policies, including the promotion of SAF through initiatives like CORSIA. 
24. IRA (Inflation Reduction Act): U.S. legislation that includes provisions for tax credits and incentives for the production and adoption of SAF. 
25. Jet-A1: The conventional jet fuel used in commercial aviation; SAF is designed to be a drop-in replacement for Jet-A1 to reduce carbon emissions. 
26. LCA (Life Cycle Assessment): A method used to evaluate the environmental impact of SAF production, from feedstock sourcing to fuel combustion. 
27. LCAF (Low Carbon Aviation Fuel): A term used to describe any aviation fuel, including SAF, that has a lower carbon intensity than traditional jet fuel. 
28. MSW (Municipal Solid Waste): Waste from households and businesses, which can be converted into SAF through processes like gasification or pyrolysis. 
29. OPEX (Operating Expenditure): The ongoing costs of running and maintaining SAF production facilities, including expenses like utilities, labor, and maintenance 
30. PNNL (Pacific Northwest National Laboratory): A U.S. Department of Energy research institution that advances technologies, including SAF production methods. 
31. PtL (Power-to-Liquid): A technology that produces liquid fuels, including SAF, using renewable electricity and captured carbon dioxide. 
32. REU (RefuelEU): An E.U. initiative aimed at increasing the production and uptake of SAF in Europe to help decarbonize the aviation sector. 
33. RFS (Renewable Fuel Standard): A U.S. federal program that mandates the blending of renewable fuels, including SAF, into the nation’s fuel supply to reduce GHG emissions. 
34. RIN (Renewable Identification Number): A tracking system under the U.S. Renewable Fuel Standard that provides credits for the production and use of renewable fuels, including SAF. 
35. SAF (Sustainable Aviation Fuel): A type of renewable fuel made from sustainable feedstocks, designed to reduce the carbon emissions of aviation compared to conventional jet fuel. 
36. SAFGC (SAF Grand Challenge): A U.S. government initiative aimed at scaling the production of SAF to 3 billion gallons per year by 2030 and 35 billion gallons by 2050. 
37. SPD (Synthetic Paraffinic Diesel): A type of renewable diesel produced from synthetic sources rather than traditional petroleum, which can be made from SAF production processes. 
38. SPK (Synthetic Paraffinic Kerosene): A synthetic jet fuel made from processes like ATJ and HEFA, certified for blending with conventional jet fuel to produce SAF. 
39. TLA (Technology Licensing Agreement): A contract that grants permission to use specific technologies or intellectual property, which can facilitate access to innovative SAF processes. 
40. UCO (Used Cooking Oil): A waste feedstock used in the production of HEFA-based SAF, providing a sustainable alternative to virgin oils.