Molten salt method converts polyethylene into fuel

Researchers at Oak Ridge National Laboratory have developed a process that uses aluminum chloride molten salts to break down polyethylene into gasoline and diesel-like fuels. The reaction occurs at relatively mild temperatures and yields about 60% gasoline. The team used spectroscopy and neutron scattering to understand the mechanism and has applied for a patent.

The ORNL process relies on aluminum chloride molten salts that serve a dual function, acting as both the reaction medium and the catalyst. Charged aluminum atoms create highly acidic sites capable of severing polyethylene's long molecular chains into shorter hydrocarbon fragments. The team employed soft X-ray spectroscopy, nuclear magnetic resonance, isotopic labeling, and neutron scattering to trace the conversion mechanism, finding that simpler polymer structures favor gasoline-range products while branched chains yield diesel-like compounds.

A standout feature is the mild operating temperature—below 200 degrees Celsius, comparable to a kitchen oven. This contrasts sharply with conventional pyrolysis, which demands intense heat. The method also eliminates the need for noble-metal catalysts, organic solvents, or external hydrogen, relying instead on commercially available inorganic salts. With roughly 60% gasoline yield and a patent application filed, the approach represents a potentially simpler route for valorizing plastic waste.