Did United Do Awesome Thing With Sustainable Jet Fuel? MOSTLY TRUE, Also SEVEN PINOCCHIOS.
Photo: United Airlines on Twitter

United Airlines reached an important milestone in moving the airline industry away from fossil fuels Wednesday, flying a Boeing 737 MAX 8 from Chicago to Washington DC with one of the plane's two engines running entirely on "sustainable aviation fuel" (SAF), a biofuel that contains no petroleum products and emits far fewer greenhouse gases than regular jet fuel. To promote industry awareness of the need to develop less carbon-intensive fuels, United invited "more than 100 partner executives, business leaders, government officials and journalists" to ride along; it wasn't a scheduled commercial flight.

Unfortunately, the airline had to go and over-hype the achievement just a bit, sending out a mass email and a tweet announcing it was set to make "aviation history" by flying on "100% sustainable aviation fuel."

About three hours after that initial tweet, though, United followed up with a clarification that the plane wasn't flying solely on SAF, because Federal Aviation Administration regulations only allow airlines to use a maximum of 50 percent SAF, which is usually mixed with regular jet fuel (and in practice, usually in smaller proportions anyway). The "historic" achievement was that the FAA had given United permission to run one engine only on SAF, while the other used regular jet fuel. It really was a first, and demonstrated that SAF can power a jet engine all on its own, and that, as a United spokesperson explained, "it proves that there is no operational difference when an engine runs on 100 per cent SAF" as compared to regular fuel, or a blend of the two.

Eventually, once the tech has been demonstrated to be reliable after Crom knows how much testing, various formulations of SAF could be used to dramatically cut the greenhouse emissions from commercial aviation by as much as 80 percent compared to conventional jet fuel. That's a heckin' big deal, since aviation is responsible for about 12 percent of CO2 emissions in the transportation sector (or two percent of all human CO2 emissions).

Not surprisingly, the reveal led some folks to accuse United of greenwashing in hyping the test, because in fact, 50 percent sustainable is not 100 percent sustainable, even if that's all the FAA will allow at this point. Aviation journalist John Walton tweeted a terse "oh for fuckssake" about the exaggeration:

We'd also add that United's email to frequent flyers didn't make any effort at all to clarify that just one engine of the flight was running on sustainable fuel, either, and it was sent after the online fuss over the Twitter announcement:

Dear Rebecca:

(It was to Rebecca.)

Yesterday was a big day for United and our planet.

We made aviation history by flying the first passenger flight using 100% sustainable aviation fuel (SAF), from Chicago to Washington, D.C. This momentous accomplishment comes nearly a year after we announced our 100% green commitment — reducing 100% of our greenhouse gas (GHG) emissions by 2050 without relying on traditional carbon offsets.

Sustainable aviation fuel really does look to be a promising way to reduce greenhouse emissions in commercial aviation. As the Independent explains, the SAF used in Wednesday's flight

was supplied by World Energy, which makes fuel from agricultural waste, waste from managed forests, and debris destined for landfill. It is a “drop-in fuel”, meaning it can be added to aircraft with no need for modifications to engine fuel systems or airline infrastructure.

Such biomass-based fuels can also be derived from "algae, crop residues, animal waste, sludge waste, and forestry residue," and municipal solid waste, so hooray, Bartertown pigshit jet fuel here we come!

United is going whole hog — or at least much-hog — on sustainable fuels, Green Biz reports, getting corporations to join something it calls the "Eco-Skies Alliance," which started earlier this year. The idea is to have corporations that do lots of business travel fund purchases of sustainable fuel with United, offsetting some of the costs, demonstrating there's a demand for greener fuels, and allowing them to talk up how their employees are travelling more sustainably, not that anyone would ever state it so cynically. Realistically, it also will give companies that purchase the low-carbon fuels to concretely demonstrate their progress toward their own goals of reaching net-zero emissions in how they do business.

The program, Green Biz notes, really is just getting underway; since Eco-Skies started up in April, the partners have

collectively contributed to the purchase of more than 7 million gallons of SAF by paying a premium for services. That’s less than 1 percent of about 4 billion gallons of fuel that United burns annually, but it’s more than double what the airline projected that corporate buyers would procure when the effort was initially announced. (The SAF purchased so far in 2021 translates into about 460 million passenger miles.)

The goal is to expand the use of green fuels industrywide, eventually getting FAA approval to use up to 100 percent SAF. But even if that were to happen immediately, United's "managing director of global environmental affairs and sustainability," Kathy Riley, acknowledged that the production of sustainable fuel would need to ramp up exponentially, as she told Fast Company:

The amount of the sustainable fuel that United has available is “far less than 0.1% of our fuel supply, and we’re the market leader,” Riley says. “So there’s just not enough right now, and that’s unacceptable.” The airline, among others, is pushing for new federal policy that would give a tax credit for alternative fuels, with the biggest incentive for producers that help reduce emissions most.

Also too, as Simple Flying notes, the current generation of sustainable fuels made from biomass is only the start; down the road (runway?), even cleaner aviation fuels are in the works, combining hydrogen obtained from water through electrolysis, and CO2 captured from the atmosphere. That's clearly a long way off, however, and would depend not only on atmospheric carbon extraction tech that's only in its infancy, but also a huge increase in the generation of renewable electricity to power the electrolysis process. But it's a neato concept at least:

Synthetic Power-to-Liquid fuels hold the promise to reduce greenhouse gas emissions by as much as 99%. If utilizing captured CO2 and green hydrogen, it can even create a carbon-neutral, circular system, picking up and using the CO2 that aviation is responsible for and turning it right back into power for the planes.

Crom only knows how airlines' PR flacks may spin the incremental improvements along the way to that.

[Independent / Simple Flying / Green Biz / Business Insider / Fast Company]

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Doktor Zoom

Doktor Zoom's real name is Marty Kelley, and he lives in the wilds of Boise, Idaho. He is not a medical doctor, but does have a real PhD in Rhetoric. You should definitely donate some money to this little mommyblog where he has finally found acceptance and cat pictures. He is on maternity leave until 2033. Here is his Twitter, also. His quest to avoid prolixity is not going so great.


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