Download document () of 20
Send email
Download
You have exceeded the download limit
Sustainable aviation fuels (SAFs) are central to the pursuit of decarbonizing global air travel. Depending on the source of the material, method of production and overall supply chain, SAFs have the potential to lower CO2 emissions by 80 percent, making them one of the most viable solutions for meeting the industry’s goal of net zero by 2050. The outlook is promising despite some of the challenges ahead. Production demands, feedstock availability and high costs prompt questions about the short- to long-term feasibility of SAF. Is it the best approach for reducing CO2 emissions? Should the industry shift more focus to electric propulsion and liquid hydrogen?
Although we don’t have all of the answers today, we’ve made significant progress to understand what SAF means for our fuel equipment, our customers and our industry.
Yes, but remember it is a more balanced—or carbon neutral—solution. SAF is produced by converting readily available materials or feedstocks (biomass, waste oils and agricultural residues) into aviation fuel suitable for mixing or as a direct replacement for existing fuels. This type of SAF is often referred to as ‘drop-in’ fuel. It’s also created through a synthetic process that involves capturing carbon directly from the air commonly called power-to-liquid (PtL).
During SAF production, CO2 is extracted from the atmosphere. While the combustion process releases CO2, as other petroleum or fossil-based fuels do, the production of the feedstock or alternative materials removes CO2 from the atmosphere. Hence, it is a balanced and sustainable solution.
Most aircraft in service were built to operate with traditional jet fuel. As we transition to cleaner, more efficient energy sources, it’s essential to ensure compatibility across the entire fuel system.
At Eaton, we work with customers to understand the impact of SAF on our fuel systems and components. Our current portfolio is compatible with drop-in SAFs.
We continue to assess the effects of non-drop in SAFs on all our equipment, even non-fuel product lines installed in zones of the airplane adjacent to fuel tanks. The elimination of aromatic content in non-drop in SAF requires modifications to nitrile-based seal components and to some fuel tank sealant materials. These materials respond beneficially to the aromatics present in conventional jet fuel.
Additionally, fuel pump performance, wear and life can be impacted by changes in the bulk properties of SAF and its chemical composition.
We continue to work alongside our customers to ensure 100% SAF is compatible with all our fuel products – from ground refueling components and main engine fuel pumps to fuel gauging technology, fuel inerting systems and more. Learn more about our comprehensive fuel solutions.
Yes—and we were proud to support two landmark journeys. In late 2023, Gulfstream completed the world’s first transatlantic flight on 100% SAF on a G600 aircraft. We ensured our fuel gauging technology would function over the seven-hour flight from Savannah, Georgia to Farnborough, United Kingdom.
Our fuel system was also onboard for Virgin Atlantic’s flight over the Atlantic Ocean from London to New York. They were the first commercial airline to use 100% SAF on the B787.
Both flights leveraged a blend of SAFs to produce a composition like the drop-in fuels discussed earlier.
While SAF continues to gain traction, it still requires more testing and development. A major hurdle is ramping up production to meet the rise in global air travel, which is expected to return to pre-pandemic levels by 2025. With jet fuel consumption reaching about 230 billion gallons by 2050, a substantial increase is necessary to power increasing air travel.
Moreover, SAF is much more expensive than traditional jet fuel to source, produce, manufacture and distribute. Fortunately, collaborative efforts among government agencies, airlines, OEMs and consumers are underway to make SAF more affordable and accessible.
Hydrogen power has emerged as a potential energy source for aviation. It can be accomplished in a few ways:
1.) In fuel cells to provide electricity for electric propulsion;
2.) Combustion within a gas turbine to provide propulsion like today’s jet engines; or
3.) As an input for PtL processes producing SAF.
As with SAF, the production process is vital to reducing CO2 emissions. If generated from renewable energy through water electrolysis, hydrogen emits no carbon emissions.
Despite the excitement about hydrogen, it’s important to remember some of the challenges. Hydrogen production at scale would require enormous amounts of energy, making it more costly than SAF. Additionally, liquid hydrogen has a lower energy density compared to conventional jet fuel and SAF and requires very low temperature cryogenic storage on aircraft to remain in a liquid state. An aircraft hydrogen tank needs to be three to four times larger than today’s jet fuel tanks.
With these issues in mind, hydrogen may be more practical for low-energy (short mission) applications whereas SAF appears to be more viable for long-haul airliners.
Presently, SAF is the most promising pathway to net zero. But we believe it will take a combination of diverse technologies—SAFs, electric and hybrid propulsion technologies, hydrogen combustion and hydrogen fuel cells—to drive long-term impact. Fortunately, we’re seeing a groundbreaking level of collaboration across stakeholders, from researchers and fuel producers to aircraft OEMs, airports and airlines, to reach net zero targets.
Despite its historic reliance on fossil fuels, the aviation industry deserves credit for how far it has come with alternative energy sources. Change takes time, but there’s a concerted effort to meet key milestones with game-changing innovations like SAF.
In the coming years, you’re likely to see more about SAF in the headlines. We also anticipate significant progress in electric and hybrid-electric propulsion, hydrogen power, eVTOL and other mid- and long-term solutions.
Eaton is committed to supporting the industry’s net zero goals through both technology and educational support. We are investing in innovations that continue to deliver the safe, efficient and comfortable air travel experience that passengers need and deserve, while minimizing the environmental footprint for future generations.
To learn more about our world-class aerospace technologies and expertise, visit eaton.com/aerospace.
