(422a) Plastic Flows and Recycling Processes in the U.S.: Material Recovery Facilities and PET Processes

Plastic flows through the economy have increased from approximately 2 Mt/year in the 1950’s to 368 Mt in 2019, with prospects for quadrupling further by 2050 [1]. Such large amounts of postconsumer use plastic could be employed in a circular economy, but only if the systems for recycling are in place and used. These system limitations represent barriers to increased recycling of plastics, which this effort examines along with the processes involved and the flows of plastics through the system. The flows of postconsumer use plastic are of interest for application in the U.S. Environmental Protection Agency’s report on Advancing Sustainable Materials Management: Facts and Figures [2]. This report includes information on municipal solid waste (MSW) generation, recycling, composting, combustion with energy recovery, and landfilling. Plastics have been identified as components of interest in postconsumer material flows. In this effort, throughputs for material recovery facilities (MRFs) are quantified to model input-output flows and for downstream processing at reclaimers, with the latter preparing the plastics for final reuse. Polyethylene terephthalate (PET) is of particular interest because it is the most widely recycled plastic. PET finds use in plastic bottles, thermoforms for food packaging, carpeting, and textiles, but only the bottles are regularly recycled. As postconsumer PET flows through MRFs and reclaimer recycling processes, the resource use and environmental releases are modeled, along with recycled flowrates and purities which describe the PET recycling system. Ultimately, the recycled PET is converted into a distribution of new products such as fibers, bottles, and films. This recycling system provides an example of a circular economy which, while only partially manifested due to limitations on collection, processing, and use of PET, offers direction on how materials can be maintained in the economy and only downcycled as appropriate [1].

[1] Smith, R.L., Takkellapati, S., and Riegerix, R.C. (2022), “Recycling of Plastics in the United States: Plastics Material Flows and Polyethylene Terephthalate Recycling Processes,” ACS Sustain. Chem. Eng., 10, 2084-2096. DOI: 10.1021/acssuschemeng.1c06845

[2] https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/advancing-sustainable-materials-management

The views expressed in this presentation are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.