Scientists have developed the world’s first technology to recycle clothing waste by converting discarded fiber into usable materials, the Korea Research Institute of Chemical Technology said Wednesday.
A group of researchers led by Cho Joung-mo, a senior researcher at the KRICT, found a screening technology that can isolate recyclable materials from clothing waste by using the chemical characteristics of dyes. The research team also came up with a recycling technology to convert separated materials into monomers.
Citing a UN report, the KRICT pointed out that the amount of greenhouse gas from the fashion industry accounts for about 10 percent of total global emissions.
The researchers applied a chemical principle to the new technology that can distinguish which discarded fibers contain polyester and isolate them. According to the study, colored fibers with polyester would be bleached while uncolored fibers with polyester would be dyed through the screening technology.
The KRICT said the technology’s rate of error is very low and it can separate high-quality polyester as it can remove the dyes, which had been difficult to extract. According to the KRICT, the technology is also eco-friendly because it uses biodegradable compounds for the screening process.
The researchers developed technology that can turn the isolated polyester -- polyethylene terephthalate, or PET -- into bis(2-hydroxyethyl) terephthalate, a high-value monomer known as BHET. Unlike the traditional pyrolysis process that required a temperature over 200 degrees Celsius to decompose polyester, the research team’s technology can complete the decomposition process at under 150 degrees Celsius.
The KRICT said the technology can significantly reduce the amount of energy required for the polyester decomposition process.
“We hope that this achievement will be a recycling technology that can reduce the generation of clothing waste in a groundbreaking manner,” said Yi Mi-hye, president of KRICT.
The KRICT said the technology has been transferred to Renew System, a local company specialized in providing sustainable solutions, for commercialization. According to the KRICT, the two plan to build a recycling plant capable of handling 10,000 tons of PET per year by the end of 2024.
The study has been published in the American Chemical Society’s Sustainable Chemistry and Engineering journal.