On Thursday, JetBlue, Virgin Atlantic, the U.S. Air Force and others announced a commitment to buy sustainable jet fuel from a New York-based startup called Air Company.

JetBlue has agreed to purchase 25 million gallons of sustainable aviation fuel from Air Company over five years, and Virgin Atlantic has agreed to purchase up to 100 million gallons over 10 years. Boom Supersonic, which is looking to revive supersonic airliners, will purchase up to 5 million gallons of this fuel on an annual basis through its Overture flight test program.

The U.S. Air Force, which awarded the company the contract, has already completed a “first-of-its-kind unmanned flight using the Air Company’s 100% unblended CO2-derived jet fuel,” according to a press release.

“The aviation industry as a whole accounts for 2-3% of global CO2 emissions and is widely considered one of the most ‘hard to decarbonize’ industries,” Air Company said in a statement. “Using the same proprietary technology that mimics photosynthesis to produce consumer ethanol, Air Company has developed a single-step process for his CO2-derived fuel production using renewable power. , has expanded.”

As companies look to technologies that can help them reduce their dependence on fossil fuels, there is a lot of new research and investment in developing sustainable aviation fuels. Electric and battery-powered vehicles are also being considered as alternatives to air transportation, but they can come with their own set of challenges. Electric aircraft may work for short hops, but are not suitable for long trips. Therefore, there is a need for a more environmentally friendly way to power aircraft combustion engines.

So what is sustainable aviation fuel?

Conventional jet fuel, or kerosene, is a mixture of hydrocarbons made from a series of chemical reactions.But to make it sustainable, instead of using fossil fuels, engineers instead integrate more renewable starting materials, such as raw materials, and waste, such as used cooking oil (read pop rhinocerosClick here for a speaker on sustainable aviation fuels). The general idea is that even if you burn it and it emits carbon pollution, it will eventually become “carbon neutral” because the carbon is removed from the air during the manufacturing process.

Sustainable aviation fuel (SAF) can be made from carbon dioxide and hydrogen. This subset of products is called Synthetic SAF.

[Related: The truth about carbon capture technology]

Air Company co-founder Stafford Sheehan said in a press release: (The Fischer-Tropsch system turns hydrogen gas and carbon monoxide into water vapor and hydrocarbons through reactions that rearrange bonds between the compounds. The source of carbon monoxide is typically coal or natural gas. ) produces fuel compositions that can be used in jet engines without the need for mixing with fossil fuels, as demonstrated in test flights with the U.S. Air Force. Our one-step process makes SAF more cost-effective and widely available. ”

The company described the complete fuel-making process in a white paper published in the journal. ACS Energy LetterEarlier this year, the company conducted a small-scale experiment to make ethanol from thin air through products such as vodka, hand sanitizer and perfume.

The US has already approved the use of SAF in blends with conventional jet fuel. European researchers have been looking at ways to reconfigure the original jet fuel production process using renewable and non-fossil fuel starting materials. However, efficiency is a barrier, and so is cost. SAF is reportedly two to four times more expensive than conventional jet fuel, and Air Company is no exception to this problem.The company’s CEO said Axios Their SAF is “far from cost-equivalent to conventional jet fuel,” but SAF-specific incentives included in the Inflation Reduction Act should cut some of the costs. The availability of SAF compared to fuel.

Several companies are testing small-scale flights with this greener alternative to jet fuel, but there are still questions about how well SAF is compatible with aircraft construction materials over long distances. remain.

But despite the skepticism and hurdles, many companies are still investing in this vision. In July, Alaska Airlines, Microsoft and Twelve announced they were working towards demonstration flights using fuel derived from captured CO2 and renewable energy. And last year, Lufthansa announced a similar agreement for the production and use of synthetic jet fuel.