A team of chemists from Japan and Malaysia has unveiled a novel method for recycling polyethylene terephthalate (PET) plastics, potentially revolutionizing how mixed waste and textiles are processed. This innovative approach utilizes an iron-based catalyst and alcohol, offering a more efficient and environmentally friendly alternative to current recycling methods.
PET is widely used in various applications, from textiles to drink containers. While PET bottles can be recycled through melting and reforming, this often results in lower-quality plastic and necessitates meticulous separation from other materials. Recycling PET from mixed waste, particularly textiles is even more challenging due to the difficulty of separating polyester from other fibers, such as cotton.
The researchers’ new method, published in Industrial Chemistry and Materials, addresses these challenges by breaking down PET at lower temperatures and without the need for corrosive chemicals. By mixing PET with ethanol and either ferric chloride (FeCl3) or iron(III) bromide (FeBr3) at temperatures between 160°C and 180°C, the team successfully converted PET into its monomer components—diethyl terephthalate and ethylene glycol—throughout a couple of days. These monomers can be reused to produce high-quality PET or other materials.
In addition to PET plastics, the method was tested on a textile blend consisting of 65% PET and 35% cotton. The process effectively separated the PET from the cotton, yielding pure cotton and monomers in just 16 hours. Moreover, the method proved capable of selectively removing PET from other textile blends, showcasing its potential for diverse applications.
The use of ferric chloride as a catalyst is particularly promising due to its low cost and widespread availability in industry. The research team is now exploring the possibility of achieving similar results under even milder conditions, which could further enhance the method’s commercial viability and environmental benefits. This breakthrough represents a significant step forward in the quest for sustainable plastic recycling.
Learn More: https://pubs.rsc.org/en/content/articlepdf/2024/im/d4im00081a
