ORNL turns plastic waste into fuel with low-temperature molten salts

Overview

Updated 1 hour ago

An Oak Ridge National Laboratory team has turned polyethylene, the most common plastic in shopping bags and cutting boards, into gasoline and diesel by stirring it into molten aluminum chloride salts at under 200°C. The reaction yields about 60% gasoline and runs at the heat of a kitchen oven, not a blast furnace.

Existing plastic-to-fuel methods, called pyrolysis, need 450-500°C, expensive catalysts, and added hydrogen gas. This process skips all three. If it scales past the lab, the hardest-to-recycle plastic becomes a cheap fuel feedstock instead of landfill.

Why it matters

If it scales, the world's most common unrecyclable plastic becomes fuel at a fraction of today's energy cost.

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Key Indicators

~60%

Gasoline yield

Share of polyethylene converted to gasoline-range hydrocarbons in lab tests.

200°C

Process temperature

Upper bound of the reaction; conventional pyrolysis needs 450-500°C.

500°C

Conventional pyrolysis temperature

Heat required by standard plastic-to-fuel pyrolysis, for comparison.

Precious-metal catalysts required

Process uses cheap aluminum chloride salts; no noble metals, solvents, or external hydrogen.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

People Involved

Zhenzhen Yang

ORNL staff scientist, co-corresponding author

Active; leads follow-up research on salt stability

Sheng Dai

Senior chemist, ORNL and University of Tennessee, corresponding author

Active

Liqi Qiu

First author, JACS paper

Active

Organizations Involved

Oak Ridge National Laboratory

U.S. Department of Energy national laboratory

Patent pending; process listed for licensing

A U.S. Department of Energy laboratory in Tennessee that ran the neutron scattering used to trace the plastic-to-fuel reaction.

Timeline

April 2025 September 2026

2 events Latest: Today

September 2026
ORNL announces process, files patent
Today Announcement

Laboratory publicly highlights the molten-salt method, which it says needs no noble-metal catalysts, organic solvents, or external hydrogen, and confirms a patent application is filed.
Today
April 2025
Peer-reviewed paper published in JACS
Publication

ORNL team publishes 'Polyethylene Upcycling to Liquid Alkanes in Molten Salts,' detailing the aluminum chloride process and its ~60% gasoline yield under mild conditions.
April 7th, 2025

Scenarios

Molten-salt plastic-to-fuel process reaches pilot scale

Possible Resolves by End of 2028

Discussed by: ORNL researchers and chemical recycling industry trackers

If the moisture problem is contained, ORNL or a licensee builds a pilot unit converting polyethylene at kilogram scale per day. The mild temperature and cheap salt would make economics more attractive than pyrolysis, which has burned investor capital at high heat. A pilot announcement would signal commercial intent.

Research team defeats the moisture-stability flaw

Likely Resolves by End of 2027

Discussed by: The paper's authors, who named stabilizing the hygroscopic salt as the next step

Aluminum chloride salts absorb water and lose stability, a barrier to any practical system. The team plans to confine the salts with halogens or carbons. A published demonstration of a water-tolerant or protected catalyst would clear the main technical risk.

ORNL signs a commercial license for the process

Uncertain Resolves by Q2 2028

Discussed by: ORNL technology transfer office, which lists the patent-pending process for licensing

The lab lists the method on its technology licensing page, inviting industrial partners. If a chemical or waste-management firm takes a license, the process moves toward real deployment. Without a licensee, it remains a laboratory capability.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

1936-1938

Houdry catalytic cracking (1937)

French engineer Eugene Houdry built the first commercial catalytic cracking unit at Atlantic Refining's Paulsboro, New Jersey refinery. A clay catalyst cracked heavy petroleum into higher-octane gasoline at lower temperatures than the thermal cracking it replaced.

Then

Higher-octane gasoline from less energy; catalytic cracking spread through the industry within a decade.

Now

Catalytic processes became the backbone of oil refining, displacing most thermal cracking.

Why this matters now

Houdry proved a cheap catalyst can slash the temperature of a hydrocarbon-breaking process. The ORNL salts do the same for plastic, cutting the operating window from roughly 500°C to under 200°C.

2005-2025

Plastic-to-fuel pyrolysis wave (2000s-2020s)

Dozens of companies built plants to melt mixed plastic waste into synthetic oil via pyrolysis, a high-heat process running at 450-500°C. Most struggled with uneven yields, feedstock contamination, and high energy costs; many shut down or never scaled.

Then

A few small commercial plants operated in Asia and Europe; several prominent North American projects closed.

Now

The sector earned a reputation for burning investor capital without solving plastic waste economics.

Why this matters now

The ORNL process directly attacks the two failure points of that wave: energy cost and feedstock tolerance. But the same scale-up and economic hurdles that sank pyrolysis still await it.