Oak Ridge Chemists Turn Everyday Polyethylene Plastic Into Gasoline-Like Fuel Below 200°C

Polyethylene is everywhere: shopping bags, food packaging, white cutting boards. It is also one of the hardest plastics to deal with once it becomes waste. Scientists at the US Department of Energy's Oak Ridge National Laboratory (ORNL) in Tennessee have reported a surprisingly simple way to turn it into something useful: liquid fuels similar to gasoline and diesel.

The method, published in the Journal of the American Chemical Society and highlighted by ORNL in September 2026, uses molten salts containing aluminium chloride. The salts act as both the solvent and the catalyst. Charged aluminium sites in the melt are strongly acidic and cut polyethylene's long molecular chains into shorter hydrocarbons. The reaction runs below 200 degrees Celsius, far cooler than the 450 to 500 degrees typical of pyrolysis, and produced a gasoline yield of about 60%. Simpler polymer chains tended to give gasoline-like products, while more complex ones gave diesel-like fuels.

“Unlike traditional techniques for converting polymer to fuel, the new process did not require noble-metal catalysts, organic solvents or external hydrogen,” said ORNL staff scientist Zhenzhen Yang, a co-corresponding author. Liqi Qiu, a postdoctoral researcher at the University of Tennessee, Knoxville, who carried out most of the experiments, pointed to the economics: “Polymer source material is abundantly available from consumer waste, and our catalyst system, aluminum molten salts, is very cheap.” ORNL Corporate Fellow Sheng Dai added that the system is stable, which could make it “radically easier to scale up.”

The team used neutron scattering at the Spallation Neutron Source, X-ray diffraction, nuclear magnetic resonance and computer simulations to understand how the chemistry works. The research was supported by the DOE Office of Science.

There are hurdles before any commercial use. The aluminium-based salts are hygroscopic, meaning they absorb water and lose stability, and the team plans to explore ways of confining them to improve separation and processing. Turning plastic into fuel also does not replace reducing and reusing plastic in the first place. But a cheap, low-temperature route that turns a stubborn waste into a valuable product is a promising addition to the recycling toolbox.