(239b) Comparative Techno-Economic and Lifecycle Assessment of Sustainably Repairable r-PET Plastics.

PET is a commonly used plastic for packaging, particularly in the bottling and beverage industries. Since these petroleum-based plastics have a long life span and do not decompose naturally, they contribute to the accumulation of "white pollution" when not disposed of properly. Due to this and inadequate waste disposal methods, they can leak into the environment. The production of PET was approximately 81 million metric tons in 2021 and is predicted to increase to 115 million tons by 2028 due to the rising global population and subsequent increase in food consumption. Despite extensive efforts to recycle bottles, only a small fraction of PET is actually recycled, and even recycled PET is frequently discarded in landfills. Furthermore, only 7% is utilized for bottle-to-bottle recycling. The experimental data used in the analysis was obtained by introducing an intelligently engineered moiety nicknamed Trojan Horse units that specifically cleave under milder conditions than traditional PET. The reactive centers initiate the PET chain’s demolition, which is expected to progress till re-polymerizable oligomers or monomers.

This research conducted a techno-economic analysis (TEA) and lifecycle assessment (LCA) of REPAIR-Enabled Environmental Degradation agents to evaluate their potential in creating economically viable and sustainable r-PET plastics. The study utilized a chemical process model based on the National Renewable Energy Laboratory (NREL) biorefinery design and BioSTEAM to benchmark the analysis against recent NREL studies.

The analysis yielded approximately $1.46/kg for the cost of traditional PET, along with 4.74 kg CO2eq/kg for emissions. However, recovering half of the discarded PET and introducing 25% BioTPA and 5% TH reduces emissions to 2.6 kg CO2eq/kg, accompanied by an increased cost of $1.84/kg. On the other hand, if the recovery rate is raised to 90%, the cost drops to $1.18/kg, while emissions decrease to 0.52 kg CO2eq/kg. These findings imply that there might be a threshold point where r-PET becomes both more affordable and sustainable than fossil-based plastics.