Development of Glycolysis Catalysts for PET Wastes Including Polyester Textiles

Polyethylene terephthalate (PET) is a versatile polymer widely used in textiles because of its chemical stability, mechanical strength, and ease of processing. However, the increasing consumption of PET, particularly in the textile industry, has led to significant environmental concerns owing to its resistance to degradation. To address these issues, chemical recycling methods, particularly glycolysis, have attracted attention for depolymerizing PET into valuable monomers for repolymerization. This review focuses on recent advances in catalysts for PET glycolysis, with special emphasis on their application in textile recycling. We categorized the catalysts into homogeneous and heterogeneous types and discussed their effectiveness in reducing the reaction temperatures and times, thereby decreasing energy consumption and operational costs. Although homogeneous catalysts achieved efficient depolymerization at lower temperatures, their post-reaction separation and purification steps remain challenging and costly. In contrast, heterogeneous catalysts offer simpler separation processes but require significant energy input. Research on the application of glycolytic catalysts in fiber recycling was also highlighted, considering the substantial use of PET in the textile industry. Finally, we suggested future research directions for developing cost-effective and sustainable catalysts that are applicable to PET fibers with the aim of enhancing the efficiency and environmental sustainability of PET recycling processes.