Life Cycle Assessment of Recycling Polyethylene Terephthalate (PET): A Comparative Case Study in Taiwan

Abstract

Polyethylene terephthalate (PET) is commonly used in beverage container manufacturing; however, its classification as a single-use plastic significantly contributes to environmental pollution. Improper disposal results in enduring contamination of both terrestrial and marine ecosystems, which poses ecological and health risks. Among the disposal methods, recycling, incineration, and landfilling, only recycling promotes a circular economy by reducing reliance on landfills, alleviating emissions, and conserving fossil resources. This study employs the life cycle assessment (LCA) method to evaluate the environmental impacts of three PET bottle recycling facilities in Taiwan, considering collection, transportation, and processing in the system boundary. It also assesses the effects of raw material composition, comparing transparent, colored, and mixed PET bottles. The results indicate that facilities processing colorless PET have lower environmental damage values (16.6–18.1 mPt·kg−1 of recycled flakes) than those handling colored and oil-trapped PET (25 mPt·kg−1) due to higher energy demands and poly aluminum chloride usage in wastewater treatment. Granulation was identified as a significant environmental hotspot for recycled PET pellets, with a damage value of 35 mPt·kg−1. Integrating renewable energy and recycled PET into PET bottle manufacturing could significantly reduce their environmental impacts. Policy recommendations include adopting renewable energies as the source energy, calibrating the use of chemicals in recycling facilities, and mandating minimum recycled content in PET products to enhance circularity.