Scientists at Oak Ridge National Laboratory (ORNL) have created a new method to transform polyethylene, a widely used plastic found in shopping bags and cutting boards, into fuels that resemble gasoline and diesel. This innovative process uses low-cost aluminum-based molten salts to break down the long chains of polyethylene molecules into smaller hydrocarbons. The technique achieves a gasoline yield of around 60%, and it operates under relatively mild conditions—temperatures below 200 degrees Celsius, similar to the heat of a typical kitchen oven. This is a major improvement compared to previous methods that required much higher temperatures, often between 450 and 500 degrees Celsius. The researchers have filed a patent application for this technology, and their findings were recently published in the Journal of the American Chemical Society. The method uses molten salts containing aluminum chloride as both the reaction medium and the catalyst. By using advanced techniques such as soft X-ray spectroscopy and nuclear magnetic resonance, the team discovered that charged aluminum atoms bind with three other atoms, forming highly acidic catalytic sites. These sites are crucial for breaking down polyethylene’s long molecular chains into smaller hydrocarbon molecules. Further experiments with isotopic labeling and neutron scattering revealed that the structure of the original polymer affects the type of fuel produced. Simpler polymer chains generally resulted in gasoline-like compounds, while more complex chains generated diesel-like fuels. If this process can be successfully scaled up from laboratory experiments, it could enhance U.S. energy security and improve industrial competitiveness by providing a new way to produce fuels from waste materials. While the aluminum-based catalytic system is both inexpensive and effective, it has a notable drawback: it is hygroscopic, meaning it easily absorbs water, which can reduce its stability. To address this issue, the researchers are now exploring ways to confine the molten salts using halogens or carbon-based materials. This could make the salts easier to handle and improve their stability. If successful, this work could significantly expand the options available for producing transportation and industrial fuels from waste plastics.