A group of researchers has developed a method to convert food waste into jet fuel, without (in theory) making any engine modifications.
Who has seen the saga of Back to the Futureknows that the brilliant “Doc” transformed the legendary DeLorean into a time machine powered no longer by rare plutonium, but by simple garbage. What then seemed like pure fantasy is now closer to reality, thanks to the work of a group of researchers from the University of Illinois Urbana–Champaign, who has developed a method to convert food waste into jet fuel, with surprising results.
The study. The research published on Nature Communicationsshows that “biofuel”, made from food waste, can meet the same standards as traditional kerosene, without modifications to the engines. A prospect that could decarbonize air transport and at the same time give a new purpose to millions of tons of organic waste produced every day around the world.
Circular energy. The idea comes from the concept of circular economy, in which nothing is thrown away but everything is transformed. In a world still dominated by a “linear” model – produce, use, throw away – the project led by professor Yuanhui Zhang proposes to recover energy and waste materials to create high-value products, such as fuel.
The airline industry is in fact one of the slowest to reduce emissions: in the United States, according to the EPA, commercial flights are responsible for 7% of transport-related greenhouse gases. Unlike cars, which can rely on increasingly high-performance batteries, airplanes require a very energy-dense fuel: a kilo of kerosene contains about 50 times more energy than a kilo of lithium battery. This is why sustainable biofuels (or SAF, Sustainable Aviation Fuel) represent one of the few realistic paths towards carbon neutrality by 2050, with the possibility of reducing emissions by up to 80%.
From food to sky. To obtain the fuel, the scientists collected food waste from processing plants and subjected it to a process called hydrothermal liquefaction (HTL). It is a sort of “pressure cooker” that replicates in a few hours what the Earth does over millions of years: transforming organic matter into a form of crude oil. From there, the material was purified and refined through catalytic hydrogenation, a process that eliminates impurities such as sulfur, nitrogen and oxygen, leaving only the hydrocarbons needed for flight. Among the catalysts tested, the most effective was the one based on cobalt and molybdenum, already used on a large scale in refineries.
The end result is a fuel indistinguishable from conventional fuel, capable of meeting the rigorous specifications established by Federal Aviation Administration and fromAmerican Society for Testing and Materials.
From theory to track. For now it is a proof of concept, but the results are promising. The fuel derived from the waste has passed all laboratory tests and could, in theory, power an airliner without any modifications to the engines.
However, other difficulties remain: producing the quantity needed for a single commercial flight would require tons of organic waste and advanced refining plants. The challenge, explains Zhang, is now to transfer the technology from the experimental field to the industry, capable of dealing with the costs and logistics of large-scale production. If successful, junk could become a new strategic resource for aviation of the future, just as the brilliant “Doc” predicted.
