United 737 MAX 8 jet powered by sustainable SAF fuel flew from O’Hare

What would normally be a ho-hum United Airlines flight from O’Hare International Airport to Washington on Wednesday Dec. 1 is being hailed as a breakthrough that will help reduce pollution from jet fuel.

That’s because the product that was pumped into the United 737 MAX 8 aircraft was sustainable aviation fuel, or SAF, which unlike petroleum uses leftovers from cooking oil, agriculture and other sources.

The jaunt to the nation’s capital, which carried more than 100 passengers including United CEO Scott Kirby and U.S. Reps. Sean Casten and Brad Schneider, is the first use of jet fuel that is 100% sustainable on a commercial flight, officials said.

“Climate change is the biggest issue our generation faces and our generation has to solve it. The implications if we don’t are catastrophic,” Kirby said.

He called the flight, where 500 gallons of SAF were used in one engine and the same amount of conventional fuel in another, “a historic day” in its impact to decarbonize the airline industry and one that will be scaled up over time. Airlines now are permitted to use only up to 50% SAF blend on board, United says.

Deerfield Democrat Schneider noted that “2% of all greenhouse gas emissions come from aviation. SAF cuts that by at least 50% or higher. If we convert the entire fleet, which is the long-term goal, that eliminates 1% of greenhouse gas emissions in just one initiative.”

In October, the aviation industry announced a 2050 target for zero carbon emissions.

Switching from petroleum-based jet fuel to alternatives means “a whole different infrastructure,” said Casten, a Downers Grove Democrat. The new fuel chain should lead to “all sorts of new jobs and innovations and all the rest of that, but you’ve got to prove you can do this at scale. So, this is the first time we’ll have enough on one plane to run the flight, and (we) look forward to a growing demand.”

The revamped fuel emits fewer greenhouse gases than traditional petroleum, according to the U.S. Department of Energy. Sustainable jet fuel comes from a variety of sources, including corn grain, algae, fats, oils and greases, agricultural residue, wood mill waste and municipal solid waste streams, the DOE reported.

Expert Gene Gebolys was asked about the recipe for the fuel on Wednesday’s flight.

“We make it out of fats, oils and greases,” said Gebolys, the CEO of World Energy, which partnered with United. “It could be used cooking oil, it could be animal fat, it could be vegetable oil like soybean oil, it can come from a variety of sources — today.”

Research is ongoing on “feedstocks of the future,” such as algae or kelp, Gebolys said.

Sustainable aviation fuels have been tested in myriad aircraft for years using blends and without needing to retrofit planes, Gebolys said, adding that greenhouse gases can be reduced by 60% to 80%.

Argonne National Laboratory Senior Scientist Michael Wang, who also flew to Washington, said the lab is collaborating with the Federal Aviation Administration on modeling greenhouse gas emissions in alternative fuels.

“Sustainable aviation fuel plays an important role in the carbon neutrality goal,” Wang said. Although battery-powered airplanes are foreseeable for short trips in the future, “for cross-country or international trips, we still need liquid fuels.”

One word of caution came from Environmental Law and Policy Center Executive Director Howard Learner.

United’s trial run “is a step in the right direction,” Learner said. “But the devil’s in the details.”

If the entire aviation industry adopts SAF, “as the airlines go up to scale, it will make an enormous difference what the feed stock is and how it is converted into jet fuel.”

For example, if recyclables such as plastics are converted en masse, that will raise questions about sustainability, Learner said. dailyherald.com