New Delhi: Researchers have developed a chemical process that produces hydrogen from plastic waste with less than half the carbon dioxide emissions of conventional industrial hydrogen production, offering a potential alternative for tackling plastic pollution and reducing emissions from hydrogen manufacturing.
The study, published in the Proceedings of the National Academy of Sciences (PNAS) was led by researchers from Ewha Womans University in South Korea.
The process uses a sodium hydroxide pretreatment that allows plastics to release hydrogen at around 350°C, significantly lower than the temperatures above 700°C required by previous methods. The lower operating temperature reduces energy consumption while also cutting greenhouse gas emissions.
The researchers reported that the method reduced carbon dioxide emissions by up to 50% for polyethylene terephthalate (PET) and by more than 98% for polyethylene compared to earlier plastic to hydrogen processes. Emissions from polyethylene were reduced to just above the clean hydrogen benchmark of four kilograms of carbon dioxide per kilogram of hydrogen, less than half the emissions generated through conventional steam methane reforming.
Unlike previous approaches that focused on specific plastics, the new technique can also process mixed plastic waste, making it more practical for countries where recycling rates remain low. South Korea, despite strict waste management regulations, recycles only about 27% of its waste, while the global average is around 9%.
Researchers said the technology could help convert difficult-to-recycle plastic waste into a valuable clean energy source while supporting industries such as steel, ammonia and chemical manufacturing that rely on hydrogen.
The team acknowledged that the technology is still in the early stages. Current experiments have been conducted on less than one gram of plastic, although researchers are now scaling the process to 100 grams. They are also working to improve hydrogen recovery efficiency and find commercial uses for the sodium carbonate by product generated during the process.
Experts noted that while the method significantly lowers emissions compared to conventional hydrogen production, hydrogen derived from fossil based plastics cannot be classified as fully green hydrogen. Nevertheless, they said the technology could become an important option for managing plastic waste while reducing industrial carbon emissions.