Clean Energy Technology

New Process Turns Mixed Plastic Waste Into Clean Hydrogen Fuel

A low-temperature chemical process can transform three common plastics into high-purity hydrogen without sorting, while trapping most of the carbon in solid or liquid form instead of releasing it as CO₂.

Plastic waste is one of the most visible environmental problems of the modern world. Every year, hundreds of millions of tons of plastic end up in landfills, rivers, and oceans, where they persist for centuries. But a new chemical process developed by researchers at Columbia University and the Korea Institute of Science and Technology could turn that waste into a valuable resource: clean hydrogen fuel.

The technique, published in the Proceedings of the National Academy of Sciences, uses a method called alkaline thermal treatment (ATT) to transform three of the most common plastics — polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) — into high-purity hydrogen gas. The process operates at much lower temperatures than traditional gasification, making it more energy-efficient and easier to scale.

Perhaps the most impressive feature is that the process does not require the plastics to be sorted by type. Mixed plastics can be fed directly into the reactor, eliminating the costly and labor-intensive sorting step that has long been a barrier to effective plastic recycling.

"We can take any plastic waste — water bottles, food containers, plastic bags — and convert it directly into hydrogen without sorting," said the lead researcher. "This is a fundamentally different approach to plastic waste management."

Equally important, the process captures most of the plastic's carbon in solid or liquid forms — such as carbonate salts and organic compounds — rather than releasing it as carbon dioxide. This means the process not only produces clean energy but also sequesters carbon that would otherwise contribute to climate change.

The hydrogen produced is of high purity — exceeding 90 percent — and can be used directly in fuel cells, industrial processes, or as a clean fuel for vehicles. Hydrogen is increasingly seen as a critical component of the global energy transition, offering a zero-emission alternative to fossil fuels in sectors that are difficult to electrify, such as heavy industry and long-distance transport.

While the technique is still at the laboratory scale, the researchers are optimistic about its potential for commercialization. They estimate that a full-scale facility could process tens of thousands of tons of plastic waste per year, producing enough hydrogen to power thousands of homes while simultaneously addressing the plastic pollution crisis.

The study was funded by the National Research Foundation of Korea and the U.S. Department of Energy. The team is now working on scaling the process and improving its efficiency before moving toward pilot-scale demonstrations.