The environmental and economic impacts
of implementing a circular
economy in plastic waste supply chains are not well understood. The
proposed systems analysis framework assesses environmental, social,
and economic impacts of plastic waste supply chains in a circular
economy. The first objective of this article is to identify data sets,
models, and knowledge gaps associated with waste plastic supply chain
processes, mainly in the U.S. Our literature review indicated that
the best data sets exist for virgin plastic resin production, mechanical
recycling, landfilling, and incineration, with the materials recovery
facility being intermediate, and with chemical recycling the lowest.
The second objective of this perspective is to develop an illustrative
application of the framework by conducting a preliminary systems analysis
of PET bottles with closed-loop recycling. The preliminary systems
analysis of polyethylene terephthalate (PET) bottles utilized a linear
programming optimization method. Our optimization model indicated
that both chemical and mechanical recycling processes are needed to
achieve a true circular economy of PET bottles with the least greenhouse
gas emissions, specifically reductions of 24% when compared with the
linear economy. Good quality and standardized life cycle assessment
and techno-economic analysis studies are needed to better understand
the environmental, economic, and social impacts of advanced sorting
and chemical recycling technologies.