Trash that would otherwise rot in landfills could be converted into 62.5 billion liters of jet fuel per year, with a carbon footprint 80-90% smaller than that of fossil-based aviation fuel, according to a new study (1). Aviation represents 2-3% of global greenhouse gas emissions and is extremely hard to decarbonize. One potential solution is sustainable aviation fuels (SAFs) made from renewable feedstocks. But some of these feedstocks come with their own problems – biofuel crops can displace natural ecosystems or food crops, for example.
That has produced a surge of interest in making fuel from various forms of waste. “There is a wealth of organic waste deserving our attention,” says study team member Michael McElroy, professor of environmental studies at Harvard University in Cambridge, Massachusetts.
“Using these wastes as feedstocks could reduce the cost of the decarbonization transition for hard-to-abate sectors.” Municipal solid waste is a great potential feedstock because there’s already a collection system for it and it’s abundant all year round. But trash-based fuel hasn’t been the subject of much research. The new analysis is the first to use real-world data from commercial facilities involved in various production steps to calculate the potential of this approach at a global scale.
Making fuel from trash is challenging because the material is so heterogeneous. That means more steps and more energy used for manufacturing and refining the fuel. Still, the international team of U.S. and Chinese researchers calculated that globally, more than 62.5 billion liters of trash-based jet fuel could be produced each year.
Incorporating it into the aviation fuel supply would reduce greenhouse gas emissions associated with the industry by 16%. The initial step of turning solid waste into a mix of gases emerged as particularly tricky. “Gasification technology remains a core technical challenge in biomass energy development,” says study team member Ming Zhao, professor of environmental engineering at Tsinghua University in Beijing, China.
“Its reliability and efficiency are crucial to the sustainability of green fuel synthesis, and progress on low-carbon fuels, whether methanol or Sustainable Aviation Fuel, depends on advancing this process.” .IRPP_ruby , .IRPP_ruby .postImageUrl , .IRPP_ruby .centered-text-area {height: auto;position: relative;}.IRPP_ruby , .IRPP_ruby:hover , .IRPP_ruby:visited , .IRPP_ruby:active {border:0!important;}.IRPP_ruby .clearfix:after {content: "";display: table;clear: both;}.IRPP_ruby {display: block;transition: background-color 250ms;webkit-transition: background-color 250ms;width: 100%;opacity: 1;transition: opacity 250ms;webkit-transition: opacity 250ms;background-color: #eaeaea;}.IRPP_ruby:active , .IRPP_ruby:hover {opacity: 1;transition: opacity 250ms;webkit-transition: opacity 250ms;background-color: inherit;}.IRPP_ruby .postImageUrl {background-position: center;background-size: cover;float: left;margin: 0;padding: 0;width: 31.59%;position: absolute;top: 0;bottom: 0;}.IRPP_ruby .centered-text-area {float: right;width: 65.65%;padding:0;margin:0;}.IRPP_ruby .centered-text {display: table;height: 130px;left: 0;top: 0;padding:0;margin:0;padding-top: 20px;padding-bottom: 20px;}.IRPP_ruby .IRPP_ruby-content {display: table-cell;margin: 0;padding: 0 74px 0 0px;position: relative;vertical-align: middle;width: 100%;}.IRPP_ruby .ctaText {border-bottom: 0 solid #fff;color: #0099cc;font-size: 14px;font-weight: bold;letter-spacing: normal;margin: 0;padding: 0;font-family:'Arial';}.IRPP_ruby .postTitle {color: #000000;font-size: 16px;font-weight: 600;letter-spacing: normal;margin: 0;padding: 0;font-family:'Arial';}.IRPP_ruby .ctaButton {background: url(https://www.anthropocenemagazine.org/wp-content/plugins/intelly-related-posts-pro/assets/images/next-arrow.png)no-repeat;background-color: #afb4b6;background-position: center;display: inline-block;height: 100%;width: 54px;margin-left: 10px;position: absolute;bottom:0;right: 0;top: 0;}.IRPP_ruby:after {content: "";display: block;clear: both;}Recommended Reading:Jet fuel from paper industry waste could make airplanes cleaner But researchers are working to improve gasification and other processes involved in making SAFs. In a separate study, researchers at the University of Illinois developed a new method for making jet fuel from food waste, which comprises the largest share of municipal solid waste in many areas (2).
It’s pretty easy to turn food waste into a high-energy liquid fuel through a process known as hydrothermal liquefaction. The problem is that this biocrude oil has a varied chemical composition, but the jet fuel needs to be uniform and extremely precise. The researchers tested dozens of chemical catalysts for refining the biocrude and hit upon one containing the elements cobalt and molybdenum that can do the job in a single step, resulting in jet fuel that meets current industry standards.
While the result could be fine-tuned further, the researchers say it is the first food-waste-based jet fuel that could be used directly in airplanes without needing to be blended with fossil-based jet fuel. The food-waste biocrude could also be refined into gasoline and diesel fuel, the researchers say. But while both food waste and municipal solid waste could be part of the solution to SAFs, neither is sufficient to replace conventional jet fuel completely – a sobering reminder of just how much fuel airplanes (and other fossil-based forms of transportation) burn.
Sources: (1) Zhang J. “Powering air travel with jet fuel derived from municipal solid waste.” Nature Sustainability 2025. (2) Summers S. “From food waste to sustainable aviation fuel: cobalt molybdenum catalysis of pretreated hydrothermal liquefaction biocrude.” Nature Communications 2025.
Image: based on Chalabala/iStock.com / ©Anthropocene Magazine.
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