Recycling mixed plastic: Researchers develop world-first tech without sorting

15 Sep 2025

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Dr. Young-Hoon Song, head of Center for Plasma Process for Organic Material Recycling at KIMM, and Dr. Dae Hoon Lee, head of the Nitro-Future Initiative Global Top Reserch Lab.

Korean scientists have unveiled a technology that can chemically recycle mixed waste plastics into raw materials, without the need for precise sorting or label removal from packaging waste.

Dr. Young-Hoon Song, head of the program, says: “Through demonstration and commercialization, this [technology] will help solve both waste and carbon issues simultaneously.”

The “highly selective” technology announced by the Korea Institute of Machinery and Materials (KIMM) under the National Research Council of Science and Technology is said to mark a “global first process that can economically convert mixed waste plastics into raw materials.”

The innovation develops a plasma conversion process to transform plastic waste into raw chemical feedstocks, such as ethylene and benzene. The technology was developed by KIMM’s Center for Plasma Process for Organic Material Recycling in collaboration with several institutions and universities. 

Dr. Dae Hoon Lee, head of the Nitro-Future Initiative Global Top Research Lab, adds: “In addition to the process technology, several key sub-technologies were developed during this project, which could be extended to GHG treatment in semiconductor and display manufacturing, as well as high-value material production.”

Reshaping chemical recycling

Compared to conventional pyrolysis, the newly developed process can convert mixed waste plastics using plasma — a highly energized gas at extreme temperatures with much faster reaction kinetics and higher energy transfer efficiency.

At the heart of the innovation is said to be the world’s first ultra-high-temperature plasma torch powered entirely by hydrogen. Operating between 1,000 and 2,000 degrees Celsius, the torch decomposes plastic in less than 0.01 seconds. 

The technology offers an alternative to incineration, improving plastic recycling solutions.

The researchers achieved selectivity levels of 70–90% and ethylene yields exceeding 70% by controlling reaction temperature and time. After purification, over 99% of the output could be secured as “high-purity raw material” for new plastic production.

“Its ultra-high-temperature operation rapidly breaks down polymer structures while suppressing carbon formation by using 100% hydrogen fuel. As a result, the process not only secures long-term operational stability but also enables the selective conversion of over 70–80% of the outputs into ethylene and benzene,” say the researchers.

Waxes, which are previously unusable in pyrolysis, could also be converted at more than 80% selectivity from mixed waste.

“Once commercialized, this technology is expected to dramatically increase Korea’s chemical recycling rate for waste plastics, which currently stands at less than 1%. It offers a powerful alternative to incineration, with significant potential for carbon reduction,” the scientists explain. 

“Moreover, when powered by renewable energy, the process could become virtually carbon-free. Pilot operations have already demonstrated economic feasibility, showing that the production cost of ethylene is comparable to that of existing feedstocks.”

Long-term recycling operations are planned to begin in 2026 to accelerate commercialization.