Recycling and high-value utilization of polyethylene terephthalate wastes: A review

Polyethelene terephthalate (PET) is a well-known thermoplastic, and recycling PET waste is important for the natural environment and human health. This study provides a comprehensive overview of the recycling and reuse of PET waste through energy recovery and physical, chemical, and biological recycling. This article summarizes the recycling methods and the high-value products derived from PET waste, specifically detailing the research progress on regenerated PET prepared by the mechanical recycling of fiber/yarn, fabric, and composite materials, and introduces the application of PET nanofibers recycled by physical dissolution and electrospinning in fields such as filtration, adsorption, electronics, and antibacterial materials. This article explains the energy recovery of PET through thermal decomposition and comprehensively discusses various chemical recycling methods, including the reaction mechanisms, catalysts, conversion efficiencies, and reaction products, with a brief introduction to PET biodegradation using hydrolytic enzymes provided. The analysis and comparison of various recycling methods indicated that the mechanical recycling method yielded PET products with a wide range of applications in composite materials. Electrospinning is a highly promising recycling strategy for fabricating recycled PET nanofibers. Compared to other methods, physical recycling has advantages such as low cost, low energy consumption, high value, simple processing, and environmental friendliness, making it the preferred choice for the recycling and high-value utilization of waste PET.