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Polyethylene terephthalate and high-density polyethylene (HDPE) have been the most commonly collected and reprocessed plastic grades during the several decades municipal recycling programs have been up and running in the United States.

Plastic packaging made of polypropylene (PP) has, for most of that time, been consigned to mixed plastics bales that for many years were most often exported to be sorted and reprocessed overseas.

The unwillingness of overseas countries—led by China—to accept these mixed bales has spurred a rethink of how to handle PP packaging scrap, and in the past several years some of those thoughts have turned into action at the collection, sorting and reprocessing levels.

Going ’round in circles

Government recycling and circular economy targets in many parts of the world and corporate sustainability goals have combined to put a certain amount of pressure on PP packaging producers and users who had been accustomed to letting their end-of-life packaging become part of low-value mixed bales.

PP as a resin is used in a wide number of industries, including within automotive components and pharmaceutical pill vials. Operators of municipal programs and material recovery facilities (MRFs) are likely most familiar with the resin when it is used to make yogurt cups and other dairy product tubs or caps for beverage containers.

Multinational brands involved in the yogurt and dairy sector, therefore, have been allocating R&D effort and investments into reprocessing the cups, tubs and lids before they draw unwelcome attention as “unrecyclable” or otherwise make for an uncomfortable presence in a corporate sustainability report.

Paris-based Danone announced commitments and actions in 2018 designed “to ensure its packaging will become 100 percent circular and to accelerate the global transition toward a circular economy of packaging.”

Danone said it was making plans to help meet collection targets set by EU regulators and to support globally “more effective publicly organized collection and recycling systems, including extended producer responsibility” systems “when relevant.”

Multinational Procter & Gamble (P&G), which includes cleaning and hygiene products brands that can be packaged in PP, has developed PP advanced recycling technology that is being commercialized by Florida-based PureCycle Technologies Inc.

That company’s inaugural facility in Ironton, Ohio, is scheduled to open in 2022 and has presold more than 20 years of output, according to PureCycle. The company announced its intention to build a second facility near Augusta, Georgia, this July.

PureCycle will use proprietary technology it has licensed from P&G to recycle PP scrap into “virgin-like” resin the company says can be used in a variety of applications, including consumer goods, automotive, building and construction and industrial uses. The company says it plans to reach 500,000 tons of production across its network by 2025.

Capacity at that level would be a game-changer, though PureCycle has been identified by Hindenburg Research, a skeptical investment researcher, as having rewarded corporate officers with bonuses before it has met any production targets. The same research firm also interviewed mechanical recycler Scott Saunders, general manager of Troy, Alabama-based KW Plastics, who later confirmed to Recycling Today that he has not seen documentation of how PureCycle’s technology will work. Saunders also expressed reservations about chemical recycling efforts sewing confusion into the secondary markets long established for mechanical recyclers.

For a PP loop to be closed by mechanical or chemical processes, collection efforts also need to be made more feasible and attractive, which is where The Recycling Partnership is attempting to play a significant role.

No longer part of the mix

Campaigns with names like “All Bottles” were used several years ago to prompt the additional collection of household PP scrap, though at that time it was so the PP could be part of a mixed bale likely exported to Asia.

With that shipping lane largely closed, haulers and MRF operators have been faced with either ceasing the collection of No. 5 PP scrap or connecting with companies and organizations that can make collection worthwhile again.

The Recycling Partnership, Falls Church, Virginia, is funded in part by brand owners, plastic producers and retailer-related organizations, such as Keurig Dr Pepper, Braskem and the Walmart Foundation.

In an article in the summer 2021 edition of Plastics Recycling magazine co-authored by Katherine Huded and Rich Simon of The Recycling Partnership, the duo spell out how that organization “leverages a combination of grant funding and private facility investments to activate rapid change” in the PP recycling sector.

MRF operators or other recipients that receive grants are “making equipment installations within six months, on average, of receiving grant funding,” Huded and Simon write. “In just one year, the coalition provided nearly $5 million in grants and catalyzed an additional $10 million in private investments to inject much-needed capital in PP sorting within MRFs across the country,” they add.

In Cincinnati, Rumpke Waste & Recycling has invested almost $2 million, including some grant funding made possible by The Recycling Partnership, to install three robots at its MRF in that city. Rumpke says the investment will help its Cincinnati MRF to “better sort plastic containers from the rest of the recycling stream” and the investment “supports new recycling growth for the region.”

“Robotics are the latest and greatest technology in the recycling industry,” says Jeff Snyder, recycling senior manager at Rumpke Waste & Recycling. “We are very excited to be the first recycling facility in Ohio to add this cutting-edge technology.”

Snyder says the facility is the first among Rumpke’s MRFs to integrate robotics and one of the first MRFs in the Midwest to incorporate robotics.

Because of The Recycling Partnership involvement, the robots are being configured to help the plant recover PP from the inbound material stream. Rumpke says it also plans to add two more robots in the coming months to help the plant further improve the quality of its sorted PP scrap.

Rumpke says it invested in SamurAI robots made by Canada-based Machinex. The company says the robots use artificial intelligence to identify materials and engage articulated arms to grab the material and direct it through the plant. The robots can make about 70 picks per minute.

Prior to this investment, Rumpke says it recovered “some PP,” but with the robots the facility can “significantly increase” its PP recovery rates.

Other PP-related grants (including six announced in late August) went to MRF operators in several different regions of the country, casting a wide net that could help determine whether a larger and resolute PP scrap market can be established in North America.

Single and loving it

Photo courtesy of Unilever

Global pricing services provider S&P Global Platts has identified Western Europe as a geographic region that could be ahead of the U.S. when it comes to establishing recycled-content PP scrap pricing.

In late July, S&P Global Platts launched six new daily price assessments in the recycled plastics sector, with two of them being for black recycled polypropylene (r-PP) pellets and clear r-PP pellets delivered duty paid (where applicable) within a Northwest Europe region that is identified as including Belgium, France, Germany, Luxembourg, the Netherlands and Switzerland.

Plastic scrap pricing benchmarks such as those offered by S&P Global Platts can also be key components in the “decoupling” of plastic scrap prices from virgin resins, which tend to rise and fall with petroleum demand, pricing and refining activity.

In an interview conducted last year with Recycling Today, Max Craipeau of Singapore-based Greencore Resources Ltd., a plastics reprocessor and trader, said such price decoupling results in “higher prices for recycled content” that “drive up collection and processing, turning the whole value chain into a profitable business.”

Craipeau trades plastic scrap (including PP) in Asia and Europe and operates reprocessing plants in Indonesia and Poland. He also serves on the Plastics Committee of the Bureau of International Recycling, Brussels.

His sentiments likely are shared by most plastics recyclers in North America, who would prefer to see pricing based on supply and demand for plastic scrap in their operating region that is separate from the vagaries of the global petroleum market.

“Contrary to fossil fuel feedstock, from which virgin plastics are made, recycled feedstock is more limited or difficult to access,” Craipeau said in 2020. This can put a floor on pricing for PP and other plastic scrap “no matter what happens to their virgin counterparts linked to oil price variations,” he added.

S&P Global Platts is thinking similarly, though some of its most recently introduced U.S. prices (for HDPE scrap) include PP as a contaminant rather than a traded commodity.

However, the more PP scrap is collected and the more companies like KW Plastics invest in reprocessing it, the faster it can lose its status as a contaminant.

The author is senior editor with the Recycling Today Media Group who can be contacted at btaylor@gie.net.