Plastic rubbish keeps piling up, and researchers think some of it could be turned into hydrogen fuel instead.
Researchers at Ewha Womans University in South Korea and UCLA detailed a process that turns mixed plastic waste into high-purity hydrogen without the very high temperatures many similar systems rely on, according to Gizmodo.
The method is called alkaline thermal treatment, or ATT. It uses heat and sodium hydroxide to break down common plastics and generate hydrogen gas.
The researchers said ATT is meant to address two persistent problems at once: the higher temperatures linked to gasification and the extensive sorting that makes conventional recycling expensive.
That matters because plastic recycling still handles only a small share of the material produced worldwide. Research cited in the report found that just 9 percent of plastic was recycled in 2022, while 40 percent went to landfills and 34 percent was burned.
Plastic use is also projected to rise from about 464 megatons in 2020 to about 884 megatons by 2050.
Woo Jae Kim, a professor of chemical engineering and materials science at Ewha Womans University in South Korea and a co-author of the study, said the condition of discarded products helps explain why mixed plastic waste is hard to process.
“In practice, discarded plastics are often mixed, contaminated with food, adhesives, labels, dyes and other additives, or combined in multilayer packaging,” Kim said.
In lab experiments, the researchers used ATT on PET, PE and PP, three common plastics, and produced high-purity hydrogen with yields comparable to pyrolysis and gasification. They also reported negligible direct carbon emissions from the reaction itself.
The researchers present ATT as an alternative to two existing methods. Pyrolysis usually works better with cleaner, better-sorted plastic streams, while gasification can process mixed plastics but requires much higher temperatures and more energy.
ATT is meant to sit between those options by reducing sorting needs, lowering heat demands and producing cleaner output.
The team adapted ATT from an earlier approach developed to turn biomass feedstocks such as seaweed into hydrogen without increasing net carbon, Gizmodo reported.
In the plastic-focused version, PET broke down more easily, while PE and PP performed better after a mild pre-oxidation step before the main reaction.
Julie Zimmerman, an endowed professor of chemical and environmental engineering and vice provost for planetary solutions at Yale University, said the study appears promising but remains in its early stages.
Zimmerman described the study as an “interesting and potentially important reaction concept,” but said the current results “establish chemical feasibility rather than technical or economic viability.”
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