Critical economic and environmental factors in plastics recycling

Plastic recycling offers a promising pathway to decrease the consumption of petrochemicals while also potentially reducing associated environmental impacts, such as the embodied greenhouse gas (GHG) emissions. Although specific commodity plastics such as PET, HDPE, and PP can be effectively recycled via established mechanical methods, more highly contaminated, heterogeneous, or low-volume plastic waste is currently recycled to a limited degree, or not at all. To address this gap, numerous recycling technologies are being developed and, in some cases, deployed to valorize various waste plastic feedstocks. While assessment of a new technology's feasibility often focuses on key process-level variables such as conversion and yield, broader challenges associated with the feedstock availability, purity, and price can often dominate the overall process costs and therefore play a pivotal role in a technology's success. Here, these considerations are explored through the lens of techno-economic analysis and life cycle assessment for a variety of chemical recycling technologies including the enzymatic hydrolysis of PET, the solvolysis of mixed polyesters, and the oxidative deconstruction and biological upgrading of PS.