Mariam Hassan¹, Samuel Ndlovu² and Farida Akter³
¹Department of Chemical Engineering, University of Khartoum, Sudan
²Department of Materials Science, University of Zimbabwe, Zimbabwe
³Department of Textile Engineering, Bangladesh University of Textiles, Bangladesh
Introduction
Polyester is the most widely used synthetic fiber in the world, accounting for more than half of global fiber production. According to the textile industry estimates, global polyester fiber production exceeded 65 million tonnes in 2023, driven by increasing demand from the apparel, packaging, and industrial sectors (Textile Exchange, 2024). However, the durability that makes polyester attractive also creates a significant environmental challenge, as discarded polyester products can persist in the environment for decades. With less than 1% of textile waste currently recycled back into new textiles, innovative recycling technologies are urgently needed to support a circular economy (Ellen MacArthur Foundation, 2017).
Why Mechanical Recycling Is Not Enough
Traditional mechanical recycling involves collecting, sorting, shredding, and remelting polyester waste. Although this approach reduces landfill disposal, repeated processing often degrades polymer quality, resulting in lower-value products. Contamination from dyes, additives, and blended fabrics further limits the effectiveness of mechanical recycling (Sandin and Peters, 2018).
As global textile waste continues to rise, researchers and industries are increasingly turning to chemical recycling as a solution capable of producing recycled polyester with properties comparable to virgin material.
Chemical Recycling: Closing the Loop
Chemical recycling breaks polyester polymers into their original monomers or intermediate chemicals, which can then be purified and repolymerized into new polyester. Unlike mechanical recycling, this process can handle colored, contaminated, and mixed polyester waste streams while maintaining material quality.
Polyethylene terephthalate (PET), the most common form of polyester, can be chemically recycled through several methods, including glycolysis, methanolysis, hydrolysis, and enzymatic depolymerization (Venkatachalam et al., 2012).
Glycolysis is currently among the most widely studied approaches. During this process, PET reacts with ethylene glycol to produce bis(2-hydroxyethyl) terephthalate (BHET), which can be reused for manufacturing new polyester products. Hydrolysis and methanolysis similarly recover terephthalic acid (TPA) and dimethyl terephthalate (DMT), important building blocks for virgin-quality polyester production.
Recent advances in enzyme-based recycling have attracted global attention. Scientists have engineered PET-degrading enzymes capable of breaking down polyester under relatively mild conditions, offering a potentially lower-energy alternative to conventional chemical processes (Tournier et al., 2020).
Global Progress and Industrial Adoption
Several companies have begun commercializing chemical recycling technologies. According to the International Energy Agency, improving textile circularity through advanced recycling technologies could substantially reduce greenhouse gas emissions and dependence on fossil-based raw materials (IEA, 2023).
The European Union’s Circular Economy Action Plan and various national sustainability strategies are encouraging investment in textile recycling infrastructure. Brands and manufacturers are increasingly setting targets for recycled polyester content in their products, further driving demand for closed-loop recycling systems.
Despite these advances, challenges remain. High capital costs, feedstock collection systems, energy requirements, and efficient sorting technologies continue to limit large-scale deployment. Nevertheless, ongoing innovation and supportive policy frameworks are expected to accelerate adoption in the coming years.
Conclusion
Chemical recycling represents a promising pathway for transforming polyester waste into valuable resources and reducing the environmental footprint of the textile industry. By converting discarded polyester back into its fundamental chemical building blocks, this technology enables true circularity and supports sustainable material management. As research, investment, and policy support continue to expand, chemical recycling is poised to play a critical role in closing the loop for polyester and advancing a more sustainable global textile economy.
References
Ellen MacArthur Foundation. (2017). A New Textiles Economy: Redesigning Fashion’s Future.
International Energy Agency (IEA). (2023). The Future of Petrochemicals and Circular Materials.
Sandin, G. and Peters, G.M. (2018). Environmental impact of textile reuse and recycling – A review. Journal of Cleaner Production, 184: 353–365.
Textile Exchange. (2024). Preferred Fiber and Materials Market Report 2024.
Tournier, V., Topham, C.M., Gilles, A., et al. (2020). An engineered PET depolymerase to break down and recycle plastic bottles. Nature, 580: 216–219.
Venkatachalam, S., Nayak, S.G., Labde, J.V., et al. (2012). Degradation and recycling of poly(ethylene terephthalate). ISRN Polymer Science, 2012: 1–12.
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