A major breakthrough announced in April 2026 by researchers at the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL).

They’ve developed a new chemical process that turns common plastic waste—specifically polyethylene (PE), found in shopping bags, food packaging, and cutting boards—into gasoline- and diesel-like fuels at unusually low temperatures.

Traditional methods for converting plastic waste to fuel rely on pyrolysis (heating in the absence of oxygen), which typically requires temperatures of 450–600°C (842–1,112°F) or higher. This makes them energy-intensive and expensive.

The ORNL team uses a molten salt system based on commercially available aluminum chloride-containing salts. These salts act as both the reaction medium (solvent) and the catalyst:

• The plastic is mixed directly into the molten salts.
• Charged aluminum atoms in the salt create strongly acidic “hot spots” that break the long polymer chains of polyethylene into shorter hydrocarbon molecules.
• Simpler chains produce gasoline-like fuel; more complex ones yield diesel-like fractions.

The entire reaction happens in a single “one-pot” step under mild conditions—no extra noble-metal catalysts, organic solvents, or external hydrogen gas is needed.

Key advantage: It runs at temperatures below 200°C (392°F)—roughly the temperature of a home oven—dramatically cutting energy use and costs.

Impressive results:

• Yield: Approximately 60% gasoline-range hydrocarbons under these mild conditions. interestingengineering.com
• The salts are stable, cheap, and widely available.
• The process is highly selective and scalable, addressing two big hurdles of earlier plastic-to-fuel technologies.

Zhenzhen Yang, ORNL staff scientist and co-corresponding author, highlighted: “This is the first time molten salts were used as media to produce high-value-added chemicals from waste without any catalytic initiator or solvent and at a temperature below 200 degrees Celsius.”

Liqi Qiu, a postdoctoral researcher on the team, added that the polymer source is “abundantly available from consumer waste, and our catalyst system, aluminum molten salts, is very cheap. This advance may be promising for industry.”

Plastic waste is a growing global crisis, and most polyethylene ends up in landfills or the environment. This method offers a practical way to upcycle it into valuable transportation fuels while using far less energy. The team has already applied for a patent, and the work was published in the Journal of the American Chemical Society.

The salts do have one current limitation—they’re hygroscopic (they absorb moisture from the air), so future work will focus on stabilizing them for industrial use. Still, this represents a significant step toward more efficient, lower-cost chemical recycling of plastics.

Molten salt catalysis is a powerful chemical technique where molten salts (ionic compounds melted into a liquid state) serve as both the reaction medium (solvent) and the catalyst itself.

Ordinary table salt (NaCl) melts at a scorching 801 °C (1,474 °F). But when you mix certain salts—especially aluminum chloride (AlCl₃) with sodium chloride (NaCl) in the right ratio—you create a eutectic mixture that melts at a much lower temperature (around 150 °C or 302 °F). The result is a clear, flowing liquid made entirely of ions (charged atoms/molecules) with no water or organic solvents involved.

This is the first time molten salts have been used this way for plastic upcycling at such low temperatures, and the team has already filed a patent.

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Polyethylene Upcycling to Liquid Alkanes in Molten Salts under Neat and External Hydrogen Source-Free Conditions

This is the peer-reviewed scientific paper published in the Journal of the American Chemical Society (JACS) on April 7, 2025 (issue: May 14, 2025, volume 147, issue 19, pages 16207–16216).

DOI: doi.org/10.1021/jacs.5c01107

Full citation: Qiu, L.; Polo-Garzon, F.; Daemen, L. L.; Kim, M.-J.; Guo, J.; Sumpter, B. G.; Koehler, M. R.; Steren, C. A.; Wang, T.; Kearney, L. T.; Saito, T.; Yang, Z.; Dai, S. Polyethylene Upcycling to Liquid Alkanes in Molten Salts under Neat and External Hydrogen Source-Free Conditions. J. Am. Chem. Soc. 2025, 147 (19), 16207–16216.

The work was led by Liqi Qiu (University of Tennessee, Knoxville / ORNL) with a multidisciplinary team from Oak Ridge National Laboratory (ORNL), University of Tennessee, and Lawrence Berkeley National Laboratory. Key contributors include Zhenzhen Yang and Sheng Dai (corresponding authors).

“Development of facile approaches to convert plastic waste into liquid fuels under neat conditions is highly desired but challenging, particularly without noble metal catalysts and an external hydrogen source. Herein, highly efficient and selective polyethylene-to-gasoline oil (branched C₆–C₁₂ alkanes) conversion was achieved under mild conditions (<170 °C) using commercially available AlCl₃-containing molten salts as reaction media and to provide catalytic sites (no extra solvents, additives, or hydrogen feeding). The high catalytic efficiency and selectivity was ensured by the abundant active Al sites with strong Lewis acidity (comparable to the Al type in acidic zeolite) and highly ionic nature of the molten salts to stabilize the carbenium intermediates. Dynamic genesis of the Al sites was elucidated via time-resolved Al K-edge soft X-ray and ²⁷Al NMR, confirming the tricoordinated Al³⁺ as active sites and its coordination with the as-generated alkene/aromatic intermediates. The carbenium formation and polyethylene chain variation was illustrated by inelastic neutron scattering (INS) and an isotope-labeling experiment. Theoretical simulations further demonstrated the successive hydride abstraction, β-scission, isomerization, and internal hydrogen transfer reaction pathway with AlCl₃ as active sites. This facile catalytic system can further achieve the conversion of robust, densely assembled, and high molecular weight plastic model compounds to liquid alkane products in the diesel range.”

Key Experimental Results:

• Conditions: Low-density polyethylene (LDPE) is mixed directly into a molten AlCl₃/NaCl eutectic (optimal 2:1 molar ratio). The reaction runs neat (no solvents) at 170 °C for 5 hours under inert argon (ambient pressure works fine). No noble metals, no added hydrogen, no organic solvents. osti.gov
• Performance: ~63% yield of liquid alkanes (C₆–C₁₄ range), primarily branched gasoline-range hydrocarbons (C₆–C₁₂) with some diesel-range fractions. The salts melt around 150 °C, dissolve the plastic, and catalyze cracking/isomerization in one pot. osti.gov
• Substrate versatility: Works on consumer-grade LDPE (e.g., from bags or cutting boards) and even high-molecular-weight, densely packed model plastics → diesel-range alkanes.
• Selectivity: High because the ionic molten salt stabilizes carbenium ions and prevents over-cracking or coke formation.

The AlCl₃ in the molten salt provides strong Lewis acid sites (tricoordinated Al³⁺). These abstract hydrides from the polyethylene chain, forming carbenium ions that undergo β-scission (chain breaking), isomerization, and internal hydrogen transfer — all without external H₂. Advanced in-situ techniques (time-resolved soft X-ray spectroscopy, ²⁷Al NMR, inelastic neutron scattering, isotope labeling, and DFT calculations) mapped every step.

Why This Paper Is a Breakthrough

• Mildest conditions yet for plastic-to-fuel conversion (far below typical pyrolysis >450 °C).
• Truly “neat” and hydrogen-free — previous methods needed high pressure H₂ or expensive catalysts.
• Uses cheap, commercially available salts.
• The team has filed a patent; industry interest is high because of the low energy input and scalability.

You can read the full paper (paywalled) here: https://doi.org/10.1021/jacs.5c01107
Free supporting information (methods, spectra, etc.): available on the ACS site.
ORNL summary: ornl.gov publication page