Service providers are making progress in sparking demand for SAF in business aviation, but the heavier lift is on the supply side.
SUSTAINABILITY
There is consensus that sustainable aviation fuel (SAF) is the linchpin for aviation to achieve net-zero carbon emissions by 2050; the focus now is shifting to making SAF itself sustainable. The industry’s emphasis is changing from “sustainability” to “scalability.”
Scalability will only be achieved, fuel developers and suppliers say, by building the refineries needed to produce SAF at scale and changing the mix of sustainable feedstocks used to mine carbon from fats, oils and greases to biomass, municipal waste and other sources.“Used cooking oil isn’t made [for] SAF; it’s a residual of cooking oil,” explains Alder Fuels President and CEO Bryan Sherbacow. “The fats and greases that are used are byproducts of the protein market—steak, chicken, pork and whatnot—that is being produced. There’s only so much demand for that and it grows at about 2% annually. That’s not enough to displace the amount of oil that we need in the world.”The ambition of sustainability exceeds the spigot available for SAF. Member states of the International Civil Aviation Organization (ICAO) adopted the “aspirational goal” of net-zero carbon emissions at the 41st ICAO Assembly in October, naming new aircraft technologies, streamlined flight operations and increased SAF production as the steps necessary for success. Waypoint 2050, a report issued by an international air transport industry coalition in 2021, estimated that using SAF in turbine engines will yield 53-71% of aviation decarbonization.
Avfuel and FBO Sheltair Aviation partnered to supply Neste MY SAF during the NBAA-BACE conference in Orlando. Credit: Avfuel Corp.
Aviation in the U.S. consumed 23 billion gal. of jet fuel in 2019 before the Covid-19 pandemic curbed demand; last year, approximately 5 million gal. of SAF were produced domestically, according to the U.S. government. In September 2022, federal agencies released a SAF Grand Challenge Roadmap that lays out a strategy for supplying at least 3 billion gal. of SAF per year by 2030 and enough SAF to meet 100% of aviation fuel demand—projected to be 35 billion gal.—by 2050.With less than eight years left, the path to meeting the 2030 goal requires an immediate focus on commercially ready conversion technologies and feedstocks, the roadmap advises. Lipid-based pathways using fats, oils and greases are expected to be the primary fuel pathway leading up to 2030, with a smaller contribution from municipal waste, forest and agricultural residue and alcohol pathways during that period.“Going from 5 million to 3 billion gal.,/yr by 2030 is a 600-fold increase that requires a 122% year-over-year growth in production to 2030,” the roadmap states. “It is critical this growth starts immediately. …At the same time and in parallel, the foundation must be set to achieve the longer-term 2050 goal. More than 400 biorefineries and 1 billion tons of biomass and/or gaseous carbon oxide feedstock will be needed to produce 35 billion gal./yr by 2050.”On the demand side, research commissioned by Airbus Corporate Jets (ACJ) finds that 58% of 100 senior U.S. executives surveyed expect that SAF use in private aviation will increase “significantly” over the next five years, with a further 32% forecasting at least a “slight increase.” Eighty-nine percent of the executives believe the cost of sustainably sourced jet fuel will decline as investments are made in technologies to process feedstocks more efficiently and at greater scale. Pureprofile, an independent research company, conducted the study for ACJ in September.Fixed-base operators (FBO) serving business aviation started offering SAF, initially on a demonstration basis, in late 2020. As of October, sustainability rating firm 4AIR counted 24 FBOs in the U.S. that supply SAF and 38 overall when including international locations. In addition to locations in California, FBOs also offer SAF in Colorado, Michigan, North Carolina, Oregon, Texas and Washington.
During the EBACE conference in May, British energy company BP display how SAF is derived from municipal solid waste. Credit: Bill Carey
At the NBAA-BACE conference in mid-October, Signature Flight Support said it will expand the availability of Neste MY Sustainable Aviation Fuel to all 10 of its locations in California. Signature, the largest FBO network, now pumps SAF at 17 locations. While Neste is its largest SAF supplier, Signature also buys SAF from World Energy and BP. Neste refines SAF in Houston and sources much of the feedstock in North America, says Lana Van Marter, Neste U.S. commercial development manager for renewable aviation.Service providers are making progress in raising awareness and sparking demand for premium-priced SAF in business aviation, but the heavier lift is upstream, on the supply side. The SAF distribution network in the U.S. is anchored in California, and many of the FBOs that supply SAF are clustered there and along the West Coast. Industry sources attribute the concentration of FBO locations to California’s Low Carbon Fuel Standard (LCFS), an emissions trading scheme that incentivizes the production and use of low-carbon transportation fuels, and physical proximity to the fueling infrastructure.“The reason why it’s in California today is because of the California LCFS,” says Beatrice Batty, Signature Flight Support director of fuel operations. “That makes [SAF] more economical, and consequently the production has been moved there. As other states and the federal government bring in more incentive programs, we’re going to see more of these projects move elsewhere. There are projects that are starting to be built elsewhere in the country; they’ll be disadvantaged in price from the California product because the [fuel] has to be used in California to take advantage of the LCFS.”
BP contends that producing SAF through co-processing at existing refineries will help aviation transition to a low-carbon future. Credit: BP
The Neste fuel Signature is providing is a 70/30 blend of conventional jet fuel to SAF, within the 50% SAF limit allowed by ASTM commercial specification.“There are some aircraft, usually [with] older engines and airframes, that require certain components—aromatics—of fossil-based jet fuel to maintain the health of the seals in the engine,” Batty explains. “You can go up to 50% [SAF content] but it’s also a challenge to get the right type of jet fuel that has a high enough quality to blend when you’re ready to put it into aircraft.”Neste’s Van Marter adds: “In certain cases, when the fossil fuel has the characteristics that we can blend it and hit all the chemical characteristics that you need for the older aircraft, we can go as high as 40% [SAF content]. But that is very rare at this time. The average would be like 35-37%. It really depends on the quality of the jet fuel we have to blend with sustainable aviation fuel.”Other than FBOs directly pumping sustainably sourced jet fuel, “book-and-claim” programs are the industry’s mechanism for sparking demand. Through book-and-claim, an operator flying from an airport that does not supply SAF on site can purchase—or book—a specific quantity of fuel from an FBO that does provide SAF, pay the premium, and claim an emissions reduction credit. The FBO accounts for that quantity and delivers an equivalent amount of SAF elsewhere in the supply chain.“It’s really going to be the advent of book-and-claim that is going to bring availability to locations beyond California,” says 4AIR President Kennedy Ricci. “It’s more economical, it’s more sustainable to keep it in the state. I don’t think we’ll see a huge explosion of physical supply outside of California for probably several years, until we get production outside of California,” says RicciBlenders Tax CreditIn August, the U.S. Congress passed the Inflation Reduction Act of 2022, which contained a Blenders Tax Credit that business aviation had long advocated to incentivize SAF production. The tax credit is valued at $1.25-$1.75 per gal. of SAF sold, depending on the percentage of lifecycle greenhouse gas (GHG) emissions reduced compared to fossil-based jet fuel. The credit is effective until January 2025. After that date, a new Clean Fuel Production Credit that expires in December 2027 will allow up to $1.75 per gallon for SAF with a 100% GHG reduction compared to a baseline emissions factor.“The tax credit for SAF helps level the playing field with more established biofuels and sends the right signal to investors to attract that capital that is needed,” to build out the distribution network, says Megan Eisenstein, managing director of industry and regulatory affairs with the National Air Transportation Association.Ricci believes the Blenders Tax Credit will boost SAF availability indirectly, by making it more affordable for aircraft operators. “It’s really about making it easier for adoption,” he says. “The Blenders Tax Credit is going to reduce the net cost to the end customer; in turn that’s going to allow for more adoption, and that’s going to show there is more demand. The tax incentive helps spur the momentum for SAF through the next few years by showing the demand for it, getting beyond the early adopters to a wider audience.”The Quest For FeedstocksThe incentives notwithstanding, business aviation inevitably will face competition from airlines for SAF production capacity. In April, for example, biofuel supplier World Energy announced plans to increase SAF production at its Paramount, California, facility by 700% to 340 million gal. annually. The company also said that it is pre-selling future capacity at Paramount, naming Amazon Air, United Airlines, JetBlue, Rolls-Royce and Boeing as customers.Competition also looms from other industries for renewable feedstocks used in making SAF, which are not inexhaustible, as Alder Fuels’ Sherbacow notes. Associations representing fuel retailers and trucking interests opposed passage of the Blenders Tax Credit; they argued that incentivizing SAF production will increase competition for renewable feedstocks and undercut production of renewable diesel and biodiesel.SAF contains the same hydrocarbons as conventional jet fuel but derives its hydrocarbons from more sustainable sources instead of extracting fossil-based fuel from the ground, resulting in a net reduction of emissions when compared to fossil fuel on a lifecycle basis. The current generation of SAF is HEFA-based, the acronym for Hydroprocessed Esters and Fatty Acids. It sources hydrocarbons from waste cooking oils, fats and grease.The sustainable fuel is certified to the ASTM D7566 specification for aviation turbine fuel containing synthesized hydrocarbons, which approves SAF for use in up to 50% blends with conventional jet fuel. Upon release from blending, the fuel is certified to ASTM D1655, the specification for conventional Jet A/A-1.Sustainably sourced fuel still must be blended with fossil-based fuel due to a lack of aromatics in SAF needed for seal compatibility in some aircraft engines. Newer engines are being developed to burn 100% SAF.
World Energy announced plans to increase SAF production at its Paramount, California, facility by 700% to 340 million gal. annually.Credit: World Energy
British energy giant BP contends that producing SAF through co-processing at existing refineries will help aviation transition to a low-carbon future until standalone facilities producing 100% renewable SAF to ASTM D7566 specification pick up the slack. Existing refineries now can be used to co-process 5% of approved renewable feedstocks alongside crude oil streams to meet ASTM’s D1655 standard for blended fuel, a ratio BP hopes to increase to 30%. The company’s refinery in Lingen, Germany, is already producing SAF through co-processing.“The advantage of co-processing is that it doesn’t require the significant financial investment and time that comes with building a new standalone facility,” writes Andreea Moyes, Air BP global head of sustainability, in an October opinion piece released to the press. “Also, these facilities potentially have greater flexibility in feedstocks for the coming years of energy transition, being able to switch between co-processing and the traditional processing of crude oil to meet fluctuations in demand. There are currently around 600 refineries in the world. That’s a huge manufacturing resource in terms of the opportunity to help production today.”Formed in 2019, Alder Fuels uses sustainable biomass sourced from regenerative grasses, forest residues and agricultural waste to produce Alder Greencrude (AGC), a lower-carbon crude product that can be converted into SAF using the existing biomass and petroleum refinery infrastructure. At NBAA-BACE, Alder and engine manufacturer Rolls-Royce announced a partnership to assess the performance of AGC-derived SAF, a product that Alder calls “SAF 2.0.”Engine testing will validate the performance of Alder’s SAF 2.0 as a drop-in replacement for conventional jet fuel and generate data for the development of a 100% SAF specification by standards organization ASTM, which currently prescribes fuel blends containing up to 50% SAF. Rolls-Royce already has flown its Trent and Trent XWB airliner engines on 100% SAF and has started testing its Pearl engine line for business aviation in Dahlewitz, Germany.The engine testing to date has used HEFA-based SAF, which is now considered SAF 1.0.“We are collaborating [with Rolls] on SAF 2.0 and we are taking our fuel through the ASTM approval process,” says Sherbacow. “Critically, Rolls is helping us generate the data that will be submitted through that process. While we have the technology and the capability of producing the fuel and the data about the carbon intensity of producing the fuel, we don’t have turbines, the capability to do the fuel performance or emissions testing in a turbine. That’s why these partnerships are so valuable and critical.”World Energy plans to expand the types of renewable feedstocks it uses to produce SAF with the expectation that increasing demand for waste oils, fats and greases will drive up prices.“When we’re finished with this, we’ll be able to [use] absolutely every feedstock under the sun,” CEO Gene Gebolys declared at the Paramount ribbon-cutting event in April. “We are continuing to work on new feedstocks, and we’ll source everything we could possibly source.”
—Based in Washington, DC, Bill Carey covers avionics, air traffic management and aviation safety for Aviation Week. A former daily newspaper reporter, he has covered the commercial, business and military aviation segments as well as unmanned aircraft systems. Prior to joining Aviation Week in November 2017, he worked for Aviation International News and Avionics and Rotor & Wing magazines.
