SAF: Fourth Leg of the Stool Slowly Progressing

With aviation groups setting goals of net-zero carbon emissions, the strategy behind that is often referred to as the four-legged stool, with each leg representing one of the required strategies necessary to achieve those ambitions. Among them are airframe and engine efficiency improvements, air traffic control upgrades, and market-based measures such as carbon offset purchases. But, it is the fourth leg, sustainable aviation fuel (SAF), that is both the best near-term solution as well as the one that could make the largest contribution in terms of carbon reduction.

With jet fuel having a 75-year head start, many have been frustrated at the seemingly slow pace of growth in SAF availability and its use, with global production still representing less than one percent of the total jet fuel usage.

“I think it hides the progress we’ve seen because four years ago, we were at .001 percent,” said Kennedy Ricci, president of industry sustainability solutions provider 4Air. “We basically had a handful of millions of gallons of SAF available four or five years ago; now we have hundreds of millions of gallons of production and more continuing to come online.” With global jet fuel demand currently at 90 billion gallons a year, even one percent is a significant amount, he added.

The SAF that is pumped into fuel tanks at airports is a blend of neat SAF and conventional jet-A at a ratio that is currently approved at up to 50 percent. In its blended form, it is a drop-in replacement for fossil-based jet fuel and is fully miscible, meaning it does not require separate storage from regular jet fuel.

In terms of unblended SAF, the supply in the U.S. is forecast to nearly double from last year, according to the Commercial Aviation Alternative Fuel Initiative (CAAFI), moving from 110 million gallons to more than 200 million this year, as refineries such as Montana Renewables continue to ramp up production.

The International Air Transport Association (IATA) noted that more than 140 renewable fuel projects with the capacity to produce SAF are expected to be operational by 2030. If they reach their expected output rates, worldwide renewable fuel capacity could reach nearly 40 billion gallons by that date, and possibly more.

The organization recently issued a report in partnership with Worley Consulting, concluding that technology implementation, not SAF feedstock availability, is the main pinch point in the ability of the aviation industry to reach net-zero carbon emissions goals by 2050.

According to the study, hurdles remain in current technology—mainly the slow rollout of production processes besides hydroprocessed esters and fatty acids (HEFA,) which involves used cooking oils and other fats to produce SAF.

The report notes that the bulk of the SAF required by 2050 will be derived from two main sources: sustainably-sourced biomass or power-to-liquid pathways that have been slow to enter commercial production. In all cases, the report stated, it will be necessary to improve the efficiency of the production processes, accelerate technology implementation, improve feedstock logistics, and invest in the infrastructure required to scale up production.

“We now have unequivocal evidence that if SAF production is prioritized, then feedstock availability is not a barrier in the industry’s path to decarbonization,” said IATA director general Willie Walsh. “The potential to turn SAF feedstocks into real SAF production is in the hands of policymakers and business leaders, particularly in the energy sector. We have just 25 years to turn this proven potential into reality.”

Yet not all those projects will come to fruition. In September, following an in-depth commercial and technical evaluation to reassess the project’s competitiveness, Shell subsidiary Shell Nederland Raffinaderij announced it would not restart construction of its planned biofuels facility at the Shell Energy and Chemicals Park in Rotterdam, which began in 2022. The facility, which had experienced technical difficulties in its construction, was slated to be one of the largest biofuel refineries in Europe, producing more than 800,000 tonnes of biofuels a year.

“As we evaluated market dynamics and the cost of completion, it became clear that the project would be insufficiently competitive to meet our customers’ need for affordable, low-carbon products,” said Machteld de Haan, Shell’s president for downstream, renewables, and energy solutions. “This was a difficult decision, but the right one, as we prioritize our capital towards those projects that deliver both the needs of our customers and value for our shareholders.”

“I think for a little while there was this idea of sustainability at any price, and that was just never feasible,” said Ricci. “There was no one who was willing to pay an infinite amount for the price of a gallon [of SAF], so whatever we do here has to be technically and economically competitive with options that we have in the market.”

He noted that co-processing, which uses existing refinery infrastructure to comingle crude oil and bio-crude, is being utilized by many of the European biofuel producers. “That’s just a more economical way to do it, because you don’t have to pay all the capital expenditures of either converting the plant into a biorefinery or upgrading it,” Ricci told AIN. “It gives the refinery a little more flexibility in reality.”

As for Shell, de Haan noted, “We continue to believe that low-carbon molecules, including biofuels, will underpin the future energy system.”

Another investment factor stems from policymakers, particularly in the U.S., who are not issuing strong support and incentives to encourage the development of SAF on a federal level, leading individual states to adopt their own.

“I think the pivot to many more states offering and planning incentive programs will continue to spur the demand and the production platforms that are planned for the U.S. and Canada,” said Keith Sawyer, Avfuel’s manager of alternative fuels, pointing to the lucrative Chicago market, which receives SAF via pipeline. "In time, we think we will see customers in that region, and there are quite a few of them starting to generate interest, given the state incentives that are in process.”

SAF Flow Improves

Over the past year, advances were made in the availability of SAF for business aviation users in the U.S. While it had previously been limited to the West Coast due to the proximity of the refineries (the transport of SAF before it reaches the end consumer can degrade its lifecycle carbon emissions benefits), fuel distributors such as Avfuel established new marine transport depots in Florida and New Jersey, allowing East Coast FBOs to receive and maintain permanent supplies of SAF for the first time.

“We’ve had strong [SAF] demand from the Port Everglades supply point, and it is picking up in the Northeast,” Sawyer said. “We continue to be optimistic, [overall] demand seems to be stable, although perhaps slower growth than in previous years.”

On its website, 4Air tracks the global availability of SAF in an interactive map on its website. By the end of October, the company had listed nearly 100 locations.

Yet through the book-and-claim process, SAF is much more widely available. Customers can purchase it and receive the environmental benefits, while the actual fuel is dispensed into another aircraft at an affiliated location that carries SAF, which may be hundreds of miles away.

Yet despite the existence of many SAF registries, the industry is still lacking a definitive regulatory framework to tie all of this together, according to Ricci. “We still don’t have clear guidance yet from the GHCP [Greenhouse Gas Protocol] or any of the carbon accounting standards of how we appropriately would record claims from book-and-claim, so that’s holding back some of the book-and-claim side,” he said. “I think it’s really great that we’ve got the ability for people to access SAF at pretty much most of the major business aviation airports across the U.S., but price continues to be kind of a hurdle, and policy or accounting guidance is another.”

As recently illustrated at the annual JetNet iQ summit, part of the quarterly survey sent out to worldwide business aviation operators dealt with their views on SAF usage. When asked if they will seriously consider flying with SAF in the next 24 months, while a third of the respondents indicated positive interest, nearly half disagreed.