American researchers have proposed a technology that converts polyethylene waste into gasoline and diesel fuel analogues at temperatures below 200 degrees Celsius, infohub.kz reports.
The work is being carried out by specialists at the Oak Ridge National Laboratory of the US Department of Energy (ORNL). Polyethylene is one of the most common types of plastic: it is used to make shopping bags, cutting boards, and packaging, so huge volumes of this raw material end up in landfills every year.
The new method is based on combining plastic waste with molten salts based on aluminum chloride. These salts serve simultaneously as the reaction medium and the catalyst for the chemical transformation. In experiments, the scientists achieved a yield of gasoline fractions of about 60% under relatively mild reaction conditions.
The key advantage of the technology is the low process temperature, not exceeding 200 degrees Celsius. For comparison: traditional plastic pyrolysis requires heating to 450–500 degrees. In addition, the new process does without precious metals, organic solvents, an external hydrogen source, and chemical initiators.
"The ORNL system solves two fundamental problems. First, a stable process is much easier to scale up. Second, previous systems required an initiator to start catalytic reactions, while our method does without it," noted co-author Sheng Dai.
The study also involved scientists from the University of Tennessee in Knoxville and Lawrence Berkeley National Laboratory. The results have been published in the Journal of the American Chemical Society, and the authors have already filed a patent application. In the future, the method could strengthen energy security and help address environmental pollution.