On Thursday, JetBlue, Virgin Atlantic, the US Air Force and others announced their commitment to buy sustainable jet fuel from a New York-based startup called Air Company.
JetBlue has agreed to buy 25 million gallons of the Air Company’s sustainable jet fuel over five years, and Virgin Atlantic has agreed to buy up to 100 million gallons over 10 years. Boom Supersonic, a company trying to bring back supersonic passenger flight, plans to purchase up to 5 million gallons of this fuel annually through its Overture flight test program.
According to a press releaseThe US Air Force, which awarded the company a contract, has already completed “the first unmanned flight of its kind using 100% pure Air Company CO2 jet fuel.”
“Aviation as a whole accounts for 2-3% of global CO2 emissions and is widely regarded as one of the most difficult industries to decarbonize,” the Air Company notes in declaration. “Using the same proprietary technology that mimics photosynthesis to create its consumer ethanol, Air Company has developed and implemented its one-step process to produce CO2-derived fuel using renewable electricity.”
There is a lot of new research and investment in the development of sustainable aviation fuel, as more attention is turned to technologies that can help corporations reduce their dependence on fossil fuels. Although electric and battery-powered vehicles are also being considered as alternatives to air transportation, they can come with their own challenges. Electric planes could work for short flights, but are not feasible for long trips. Hence, the need for more environmentally friendly ways to power aircraft internal combustion engines.
So what is sustainable jet fuel?
Traditional jet fuel, or kerosene, is a mixture of hydrocarbons produced by a series of chemical reactions. But to make it sustainable, instead of using fossil fuels, engineers would instead integrate more renewable source materials, such as raw materials, or waste products, such as used cooking oils (read PopSci’s sustainable aviation fuel explainer here). Overall, the idea is that even if they still emit carbon pollution when burned, because they have taken carbon out of the air in the manufacturing process, they end up being “carbon neutral.”
Sustainable aviation fuels (SAF) can be made from carbon dioxide and hydrogen. This subgroup of products is called synthetic SAF.
[Related: The truth about carbon capture technology]
“The application of our new carbon conversion process has the potential to replace legacy Fischer-Tropsch systems by simplifying a multi-step conversion to a single-step hydrogenation of CO2 to fuel paraffin,” Air Company co-founder Stafford Sheehan said in a press release. (Fischer-Tropsch systems convert hydrogen gas and carbon monoxide into water vapor and hydrocarbons through reactions that rearrange the bonds between the compounds. The source of the carbon monoxide is usually coal or natural gas.) “Furthermore, with additional modifications to the reactor, we can produce a fuel composition that can be used in a jet engine without the need for mixing with fossil fuels, as demonstrated in our test flight with the US Air Force. Our one-step process will make SAF more cost-effective, towards widespread use.”
The company laid out its complete fuel production process in a white paper published in the journal ACS Energy Letters. Earlier this yearthe company experimented on a smaller scale with making ethanol from scratch through products such as vodka, hand sanitizer and perfume.
The US has already approved the use of SAF in combination with conventional jet fuel. Researchers in Europe are looking for ways to reconfigure the original jet fuel production process with renewable energy and non-fossil fuel feedstocks. However, efficiency is an obstacle, as is cost. SAFs reportedly cost two to four times more than traditional jet fuel, and Air Company is no exception to this problem. This is what the CEO of the company said Axios that their SAF is “not close to cost parity with traditional jet fuel,” but the SAF-specific incentives included in the Inflation Reduction Act should be able to reduce some of the costs. Another obstacle is the availability of SAF compared to traditional jet fuel.
Although several companies have tested small flights powered by this greener alternative to jet fuel, questions still remain about how compatible SAFs are with the materials that make up the aircraft over long distances.
Despite the skepticism and obstacles, however, many companies are still investing in this vision. In JulyAlaska Airlines, Microsoft and Twelve said they are working on a demonstration flight using fuels derived from recaptured CO2 and renewable energy. and last year Lufthansa announced a similar agreement for the production and use of synthetic jet fuel.