(680b) Baseline Material Flow Systems Analysis of the PET and Polyolefin Plastics Supply Chains in the United States: Applications of MFA and LCA Data

Increasing production and consumption of plastic products within the current U.S. linear economy of plastics has resulted in low recycling rates and a high proportion of waste plastics deposited in landfills, incineration facilities, and leaked to the environment. High production plastics such as polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density / linear low-density polyethylene (LDPE / LLDPE), and polypropylene (PP) represented about 79% of the total plastic waste generated in the U.S. in 2018, and only 7% of these waste plastics were collected for further sorting and recycling. We present a systems analysis framework combining materials flow analysis and environmental life cycle assessment methods to evaluate environmental sustainability of all the major plastic supply chain processes for the above-mentioned plastics in the U.S. We identify the key high-emission and energy-consuming processes across the plastic supply chain, including upstream (before use stage) and downstream (after use stage / end-of-life) processes. The preliminary material flow systems analysis indicated total greenhouse gas (GHG) emissions of 102 Million Metric Tons (MMT) CO₂-eq and total energy consumption of 3,268 PJ associated with PET and polyolefin plastics supply chains. These total GHG emissions and total energy consumption represented ~ 1.54% and 3.1% of the total U.S. 2019 GHG emissions and energy consumption, respectively. The total GHG emissions and energy consumption was found to be the highest, in order, for LDPE/LLDPE, HDPE, PP, and PET supply chains. Our systems analysis framework provides guidance to multiple stakeholders involved in the plastics supply chain to identify opportunities for advancing the sustainability and circular economy of plastics. Finally, we discuss potential links and gaps at the end-of-life stage and upstream processes and provide recommendations for future work toward analyses of circular economy for plastics in the U.S.