Novel Molten Salt System Converts Plastic to Fuel

ORNL researchers develop a scalable process to turn polyethylene waste into gasoline and diesel-like fuels.

Apr. 9, 2026 at 4:54am

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A highly structured abstract painting in muted earth tones, featuring sweeping geometric arcs, concentric circular patterns, and precise botanical or physical spirals, conceptually representing the complex chemical reactions and molecular structures involved in converting polyethylene plastic into hydrocarbon fuels using a molten salt catalyst system.A novel molten salt-based system developed at Oak Ridge National Laboratory offers a sustainable and scalable solution for converting abundant plastic waste into transportation and industrial fuels.Oak Ridge Today

Researchers at Oak Ridge National Laboratory (ORNL) have developed a novel molten salt-based system that can convert polyethylene plastic waste into gasoline- and diesel-like fuels for transportation and manufacturing. The process uses an aluminum-based molten salt catalyst that is inexpensive and catalytically active, solving previous challenges with stability and the need for an initiator. The multidisciplinary team employed advanced instruments and techniques like neutron scattering, mass spectrometry, and X-ray diffraction to understand the fundamental science behind the reactions.

Why it matters

This discovery expands options for producing transportation and industrial fuels from abundant plastic waste, providing a more sustainable and cost-effective alternative to traditional fuel production methods. The molten salt catalyst system is inexpensive and scalable, making it a promising solution for industry.

The details

The ORNL team, led by Sheng Dai, developed the molten salt-based system to convert polyethylene, a widely available polymer, into hydrocarbon fuels. The key innovations include the use of an aluminum-based molten salt catalyst that is catalytically active and stable, as well as the ability to track the reaction dynamics using advanced techniques like neutron scattering and X-ray diffraction. The team identified the formation of a positively charged carbon ion intermediate that is then converted into the final fuel products.

  • The ORNL Molten Salt Reactor Experiment first demonstrated the use of molten salts in nuclear reactors in the 1960s.
  • The current research project on converting plastic to fuel using molten salts began in 2022.

The players

Sheng Dai

A researcher at Oak Ridge National Laboratory who proposed using molten salts to turn polymer waste into fuel.

Tomonori Saito

An ORNL researcher who managed the project and contributed polymer expertise.

Oak Ridge National Laboratory (ORNL)

A U.S. Department of Energy research facility that has pioneered molten salt research since the 1960s and led the development of this novel plastic-to-fuel conversion system.

U.S. Department of Energy (DOE)

The primary funder of the research through its Office of Science, which supports basic research in the physical sciences.

UT-Battelle

The organization that manages ORNL for the DOE's Office of Science.

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What they’re saying

“The ORNL system solves two fundamental issues. One, for a stable system, the process can be radically easier to scale up. Two, the previous system needed an initiator to kick off catalytic reactions. However, the ORNL system does not need one.”

— Sheng Dai, Researcher, Oak Ridge National Laboratory

“In this case we tackled polyethylene, a widely available commodity polymer, using molten salt. We're trying to understand fundamental science that will lead to discoveries and new economic opportunities.”

— Tomonori Saito, Researcher, Oak Ridge National Laboratory

What’s next

The team plans to explore ways to confine the molten salts, potentially using halogens or carbons, to improve separation and processing of the fuel products.

The takeaway

This novel molten salt-based system for converting abundant plastic waste into transportation and industrial fuels represents a significant advancement in sustainable chemistry and could lead to new economic opportunities in the circular economy.