Techno-economic, life-cycle, and socioeconomic impact analysis of enzymatic recycling of poly(ethylene terephthalate)

Esterases have emerged as important biocatalysts for enzyme-based polyester recycling of poly(ethylene terephthalate) (PET) to terephthalic acid (TPA) and ethylene glycol (EG). Here, we present process modeling, techno-economic, life-cycle, and socioeconomic impact analyses for an enzymatic PET depolymerization-based recycling process, which we compare with virgin TPAmanufacturing. We predict that enzymatically recycled TPA (rTPA) can be cost-competitive and highlight key areas to achieve this. In addition to favorable long-term socioeconomic benefits, rTPA can reduce total supply chain energy use by 69%-83% and greenhouse gas emissions by 17%-43% per kg of TPA. An economy-wide assessment for the US estimates that the TPA recycling process can reduce environmental impacts by up to 95% while generating up to 45% more socioe-conomic benefits, also relative to virgin TPA production. Sensitivity analyses highlight impactful research opportunities to pursue toward realizing biological PET recycling and upcycling.

Automated summary

Esterases play a crucial role in enzymatic PET recycling, enabling efficient depolymerization to TPA and ethylene glycol, reducing energy consumption and greenhouse gas emissions, and generating more socio-economic benefits.