Evaluation of mixed #3–7 plastic waste from material recovery facilities (MRFs) in the United States

Journal Article · Sun Sep 10 04:00:00 EDT 2023 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2023.09.002· OSTI ID:2202822

Cecon, Victor S. ^[1]; Curtzwiler, Greg W. ^[2]; Vorst, Keith L. ^[2]

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1. Iowa State University, Ames, IA (United States); Iowa State University Department of Food Science and Human Nutrition
2. Iowa State University, Ames, IA (United States)

Plastic recycling rates are still low in the United States (U.S.), with less than 10% of municipal solid waste (MSW) plastic being recycled. Most unrecycled plastics are identified by Resin Identification Codes (RIC) from #3–7, which are commonly destined for landfill or waste-to-energy facilities (WTE). Therefore, the composition and quality of outbound bales containing #3–7 plastics were assessed to understand the potential to increase recycling rates. Three bales were sourced from three different Material Recovery Facilities (MRFs) located in the United States. Each bale was manually sorted and characterized for quality and performance via multiple plastic characterization techniques. Considerable differences in bale composition were observed between MRFs, which correlated with the technology used by each MRF in the sorting process. The differences were substantial in the residual levels of poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE), which are highly desired for mechanical recycling processes and not expected in #3–7 plastics bales. Traditional recycling processes including washing, extrusion, and injection molding of the sorted material were employed prior to the physical, thermal, and molecular characterization. Despite differences in bale composition by plastic type, some polymer properties were similar across MRFs. Here, this research suggests that landfill-diverted mixed plastic waste can be utilized in the mechanical recycling of currently unrecycled materials, as processes can be designed to work with consistent polymer properties. It also highlights the need to upgrade the sorting systems to prevent waste feedstocks, which can be recycled with current technologies, from contaminating other plastic streams or reach landfills.

• Research Organization: University of Wisconsin-Madison, WI (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Bioenergy Technologies Office (BETO)
• Grant/Contract Number: EE0009285
• OSTI ID: 2202822
• Journal Information: Waste Management, Journal Name: Waste Management Vol. 171; ISSN 0956-053X
• Publisher: International Waste Working Group
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE