Scientists invent method to convert toxic plastics into fuel with 95% efficiency

Plastic waste piles up faster than we can handle it. A new lab method shows that some of the most stubborn plastics can be turned into useful fuel and a common industrial chemical in one go.

In a peer-reviewed article published in the journal Science, researchers describe a one step route that converts mixed plastic waste into gasoline range hydrocarbons and hydrochloric acid (HCI) at low temperatures.

The team reports high conversion at temperatures as low as 86 degrees Fahrenheit.

Plastics into fuel sounds like magic

Lead researcher Wei Zhang from East China Normal University (ECNU), reports that the approach handles mixed and even contaminated waste streams.

That point matters because most real world plastic waste is messy and hard to sort, much less turn into fuel.

Many households and factories use PVC in pipes, flooring, and wires, while polyolefins such as polyethylene and polypropylene dominate packaging.

Vinyl chloride, the building block for PVC, is classified as a human carcinogen.

Regulators in Europe have been reviewing the broader risks tied to PVC additives and microplastic releases.

In 2023, ECHA identified risks that may require new controls on PVC and its additives, tightening the spotlight on end of life options for these plastics. 

Today, common waste to energy routes often demand that PVC be stripped of chlorine before processing. That extra step raises costs and can limit scale.

How they do it

The method couples dechlorination with carbon carbon bond breaking and fuel building chemistry in one stage.

The outputs include chlorine free gasoline range hydrocarbons and hydrochloric acid that can be reused.

“We present here a strategy for upgrading discarded PVC into chlorine-free fuel range hydrocarbons and HCl in a single stage process, catalyzed by chloroaluminate ionic liquids. The process is suitable for handling real world mixed and contaminated PVC and polyolefin waste streams,” wrote Zhang. 

The liquid fuel falls mostly in the C6 to C12 range, the same carbon counts found in standard gasoline.

The recovered hydrochloric acid can serve as a feedstock for water treatment, metal processing, and other industrial uses.

Because the method accepts mixed PVC and polyolefins, it aims at the biggest slices of the plastic waste stream. That removes the need for very clean sorting before chemical conversion.

Chemistry that turns plastics into fuel

The reaction uses light isoalkanes, mainly isobutane and isopentane, as co-reactants and hydrogen donors. These molecules are common byproducts in refineries and can be recycled within the process.

Refineries already run alkylation units that combine isobutane with small olefins to make high octane gasoline components.

The new study taps similar chemistry while also pulling chlorine off PVC and splitting polymer chains.

Catalysts based on chloroaluminate ionic liquids promote controlled dechlorination at low temperature.

The reaction network balances endothermic steps, which absorb heat, with exothermic steps, which release heat, allowing operation near room temperature.

The team reports that carbenium ion chemistry helps crack long chains and then stitch fragments into branched fuel molecules. That branching pattern is typical of high octane gasoline components.

What the results show

In tests at 86 degrees Fahrenheit, the process reached 95 percent conversion for soft PVC pipe samples. Rigid PVC pipes and PVC wires converted at up to 99 percent at the same temperature.

When the researchers mixed PVC with polyolefin waste and ran the test at 176 degrees Fahrenheit, solid conversion reached 96 percent.

Product slates landed largely in the gasoline range, with minimal light gases and no methane detected.

The liquid products were chlorine free and mainly branched alkanes. Small amounts of unreacted light isoalkanes can be captured and returned to the reactor.

Hydrochloric acid emerged as a co-product that could be neutralized or reused. By recovering HCl, the method avoids reintroducing chlorinated organics into fuel streams.

Real world implications

The reaction runs at ambient pressure and low temperature, which hints at lower energy use and simpler equipment than high-temperature pyrolysis. That could make scale up easier where sorting is limited and mixed waste is common.

Light isoalkanes are already present in refinery systems, and alkylation units are familiar to operators. If a plant can integrate feed handling and corrosion control for acid streams, the pathway could fit into existing sites.

Because the method makes standard gasoline range molecules, the fuel can enter current distribution without special upgrades. That compatibility reduces infrastructure barriers.

The hydrochloric acid output lines up with several large industrial markets. Closing that loop raises the value of the overall product slate.

Practical questions and limits

The ionic liquid catalyst contains aluminum chloride species that need careful handling. Long term stability, deactivation by additives in post consumer waste, and catalyst recovery will drive real costs.

PVC waste carries plasticizers, heat stabilizers, and flame retardants that may interact with the catalyst.

The paper acknowledges that mixed waste introduces impurities, which may accumulate in the ionic liquid phase and affect rates.

The process uses dichloromethane as a diluent in lab tests to manage viscosity and mass transfer. Any commercial design would need solvent recovery systems and safety controls.

Corrosion, chlorine management, and material selection are central engineering issues. Those factors will influence how and where the method is deployed at scale.

Plastics, fuel, and the environment

If low temperature conversion of mixed PVC and polyolefins proves robust, it adds an option to the toolkit.

Municipal programs could route polluted streams toward chemical upcycling instead of landfilling or incineration.

Policy makers tracking health risks from vinyl chloride and PVC additives will still weigh upstream reductions and safer design.

The EPA is evaluating vinyl chloride risk under TSCA rules, and that process will inform how PVC is produced, used, and retired in the United States.

Supply chains that produce light isoalkanes and run alkylation already exist. That overlap may help early projects connect to partners and markets.

Public oversight will be needed to verify emissions and waste handling during scale up. Clear reporting will build trust as the method moves from glass tubes to industrial reactors.

The study is published in Science.

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