Mini review on life cycle assessment of chemical recycling for polyethylene terephthalate packaging: A background for UPLIFT project

Polyethylene terephthalate (PET) is one of the most widely used materials for packaging due to its excellent properties such as high strength, transparency, and recyclability. However, PET waste poses a significant environmental problem, as it can take hundreds of years to decompose and can cause pollution and harm to wildlife. To address this issue, several recycling methods have been developed, including mechanical recycling, thermal recycling, and chemical recycling. Among these methods, chemical recycling is a promising technology as it can convert PET waste into valuable chemicals and monomers that can be used to produce new PET or other materials. Life cycle assessment (LCA) is a well-established method used to evaluate the environmental impacts of a product or process throughout its entire life cycle. LCA can provide insights into the potential environmental benefits and drawbacks of different recycling methods for PET packaging. The present study begins by providing an overview of chemical recycling methods, followed by an explanation of the principles of LCA. The findings indicate that among the various impact assessment methods, six methods are most commonly used, with researchers predominantly focusing on global warming potential (GWP). The range of GWP values observed falls between -4.5 and 4.12 kg CO₂-eq. Noteworthy challenges identified in the reviewed studies encompass issues related to data availability and reliability, boundary definition, allocation methods, variability in recycling technologies, and impact assessment methods. To address these challenges, suggested improvements entail enhancing data collection and verification processes, clearly defining study boundaries, considering appropriate allocation methods, investigating the efficiency and environmental performance of diverse recycling technologies, and selecting impact assessment methods that comprehensively capture environmental impacts. Lastly, the UPLIFT project endeavors to develop sustainable PET packaging through chemical recycling, aiming to bridge the research gap in comprehensive LCA studies specifically focused on chemical recycling for PET packaging.