Report delves into recovery opportunities for food-grade polypropylene

Closed Loop Partners has released a report about the volumes of food-grade polypropylene (PP) captured at materials recovery facilities (MRFs) in the U.S.

The study was led by the Closed Loop Foundation and Closed Loop Partners’ Center for the Circular Economy in collaboration with technology company Greyparrot, London, and four U.S. MRFs: Austin, Texas-based Balcones Recycling, a Circular Services company; Hamburg, Pennsylvania-based Cougles Recycling; Cincinnati-based Rumpke Waste & Recycling; and Minneapolis-based Eureka Recycling, a portfolio company of Closed Loop Partners.

The selected MRFs were in geographically dispersed locations in the U.S., representing different communities. They also serve communities that accept and collect PP use optical sorting technology that positively identifies and sorts PP and had the basic infrastructure needed to allow the installation and operation of the analyzer. All four MRFs had an optical sorter that positively sorted PET, or polyethylene terephthalate, before the next optical sorter that positively sorted PP.

The study, made possible with funding from the NextGen Consortium and the Closed Loop Foundation, used artificial intelligence- (AI-) powered vision systems to characterize the PP recycling stream, filling data gaps on the availability of food-grade PP, which can create new opportunities to return this material to food service packaging supply chains, according to Closed Loop Partners, which is headquartered in New York City.

The project team selected Greyparrot’s AI classification technology through a competitive process according to these criteria:

• The technology had to have the ability to characterize recyclables in a MRF setting.
• The provider must perform site-specific calibration as needed to achieve acceptable accuracy.
• The technology must have demonstrated the capability to add new materials to its existing material classification technology to include different colors, formats and indications of likely food-grade material.

Closed Loop Partners says demand for recycled food-grade PP is growing, driven by policy shifts that include recycled-content mandates and extended producer responsibility (EPR), as well as by commitments from brands to incorporate more recycled materials in their packaging. Despite increased market demand, the company says data regarding the available volumes of food-grade PP in the recycling system have been unavailable as there had been no easy way to track, differentiate and separate food-grade and nonfood-grade PP.

Closed Loop Partners notes that efforts to increase PP recycling began earlier this decade with the formation of the Polypropylene Recycling Coalition, a collaboration The Recycling Partnership launched to provide funding to enhance consumer education, capture and sorting of PP, the launch of the Closed Loop Circular Plastics Strategy managed by Closed Loop Partners, which invests in solutions that advance PP and polyethylene collection and recovery in the U.S. and Canada and ongoing efforts to increase PP cup recovery by the NextGen Consortium, an industry collaboration advancing circularity for food service packaging that is managed by Closed Loop Partners’ Center for the Circular Economy.

According to the report, “While these types of initiatives have made an impact, there is a continued need to support the recovery of PP with the goal of capturing much more of the estimated 22 pounds of PP produced each year from a single-family household in the U.S.”

The study and resulting report, “What’s in a Bale? Leveraging AI to Unlock Unprecedented Recycling Data and Identify Opportunities to Recover Food-Grade Polypropylene,” revealed the contents of the PP recycling stream, including the volume of food-grade and nonfood-grade items, as well as color, format and other critical identifying features. Nearly 45 million individual PP and non-PP objects were characterized during the study, revealing details on the PP packaging in the stream:

1. Clear and white food-grade PP is abundant. On average, more than 75 percent of the PP captured in the study was white or clear, most of which also was presumed to be food grade. Furthermore, more than 30 percent of the clear PP packaging was beverage cups.

2. AI-enabled technologies can reliably quantify and classify recyclables with granularity at scale. AI systems, such as the Greyparrot Analyzer, proved reliable in providing effective material characterization data at previously unavailable scales. This indicates the potential for AI to drive value to MRFs through increased intelligence and data granularity on material flows, Closed Loop Partners says.

3. AI can help measure and track facility and equipment performance. Upgrades to optical sortation technology at MRFs had a notable impact on improved material sorting, Closed Loop Partners says. This was progress that the AI technology was able to track and provide critical analytics on, indicating the potential for AI to offer enhanced performance evaluation data for MRF operators.

Regarding the last point, according to the report, “Contemporary optical sortation technology provides dramatically better separation performance for recyclables. During this study, one MRF replaced an optical sorter that had reached the end of its service life. The AI classification system effectively quantified a 13 percentage-point performance improvement in PP purity after the new optical sorter’s installation.”

“The data captured demonstrates what is possible for the future of recycling and circular materials management when powered by technology that can enhance transparency in the recycling system and increase high-quality material recovery,” says Kate Daly, managing partner and head of the Center for the Circular Economy at Closed Loop Partners. “As we continue our work with many of the world’s largest retailers and food service brands, we look forward to identifying more opportunities to pull valuable food-grade materials back into foodservice packaging supply chains––a critical step toward recycled content goals and packaging circularity.”

“This work provides important data and transparency around the performance of AI technology and its capabilities within MRFs,” says Gaspard Duthilleul, chief operating officer of Greyparrot. “We are proud to contribute critical data on the presence and quantity of food-grade objects within the PP stream. In just three months, Greyparrot Analyzers characterized over 45 million PP and non-PP materials—a process that would take nearly four years manually, as manually characterizing just 1,000 pounds of material can take an entire day. This scale uncovers new opportunities for data collection at recycling facilities, serving as the foundation for increased recovery of valuable materials.”

Closed Loop Partners says that while the characterization study focused on uncovering better data at one node of the PP recycling value chain, the results reveal that strong recycling data can enhance recovery opportunities and create new value up and down the recycling system and lay the groundwork for additional studies that can generate new, valuable recovery opportunities further downstream. Additional studies could focus on ways to further leverage large-scale, granular data from AI technology strategically deployed at various points in MRFs, plastics reclaimers and elsewhere across circular supply chains. This could facilitate identifying the effect of different communication and education protocols on the quantity and characteristics of materials captured and inform new operating practices that could yield better financial outcomes in recycling systems.

Moving forward, Closed Loop Partners’ Center for the Circular Economy says will continue to identify opportunities to leverage new data and innovations to advance material recovery with the recycling industry and global retail and food service brands.