Will plastics recycling meet its deadline?

AMP Robotics has a Silicon Valley–type solution to the knotty problem of postconsumer plastics: How do you harvest valuable materials from dirty streams of mixed waste?

AMP’s technology is based on machine learning and works on the same principles as phone apps that identify wildflowers, or sensors in autonomous vehicles that scan the road. “These approaches are fundamentally using a form of pattern recognition that is based on training in an artificial neural network,” says Rob Writz, AMP’s director of commercial partnerships.

AMP’s machines, deployed in 160 recycling facilities across North America, “infer in real time” what items are whizzing by on a conveyor belt, Writz says. If they identify an unwanted object—a metal can contaminating a stream of plastic beverage bottles, for example—a pneumatic arm descends to suck it off the line.

The machines are discriminating, Writz says. They can tell polypropylene cups from polystyrene ones, recognizing the differences in luster, clarity, and the patterns they exhibit when bent and distorted. And they can do the job of identifying objects and pulling them off the line twice as fast humans, who can pluck out only about 40 objects from a stream per minute.

Plastics recycling desperately needs such innovation. Despite years of lip service to the need to recycle, the US plastics recycling rate is still less than 10%, according to the Environmental Protection Agency. Other regions perform better but need improvement. In Europe, for example, the rate is nearly 33%, according to Conversio Market & Strategy.

Improving recycling will require new technologies to solve the problems that make plastics difficult to recycle. It will also demand collaboration and investment across the complex ecosystem of brand owners, consumers, municipalities, waste management firms, recyclers, and chemical companies.

Lofty goals for brands

Facing mounting pressure over plastic waste, industry has promised to improve. The world’s largest consumer product companies—Coca-Cola, Unilever, PepsiCo, and others—have set ambitious targets for replacing virgin resins with recycled ones, a typical goal being 25% by 2025. The undertaking is massive. Coca-Cola alone produces 112 billion plastic bottles a year, enough to buy the world a Coke, as the firm’s famous ad campaign suggested, 14 times over.

To help hit these targets, chemical companies are promoting chemical recycling—processes such as depolymerization and pyrolysis that break down plastics into feedstock that can be converted into new plastics. But chemical recycling is largely untested, with the first large-scale plants only starting to come on line.

For now, plastics recycling relies almost exclusively on traditional mechanical recycling—as it has for decades.

This decidedly unglamorous process starts when residents leave recyclables for their local trash haulers. Materials recovery facilities sort the metal, glass, and plastics with equipment such as optical sorters that use infrared light to separate plastics or the newer artificial intelligence machines from AMP. Material reclaimers shred, wash, melt, and repelletize the plastics for sale to molders. Higher-purity resins destined to go back into food packaging go through more meticulous finishing steps.

To reach their ambitious goals, consumer product companies will need to draw from this system more than ever before. Coca-Cola aims for 50% recycled content across all its packaging by 2030. But in 2020 it was 22%, and just 11.5% for polyethylene terephthalate (PET), the main polymer used in beverage bottles. Keurig Dr Pepper has reached only 2% recycled plastic against a goal of 25% by 2025.

Many of these firms are introducing recycled packaging for their most famous brands to boost their numbers and signal to the public that they care. In 2019, Unilever introduced its Hellmann’s mayonnaise in containers with “Jar Made from 100% Recycled Plastic” printed conspicuously on the label. Coca-Cola launched 100% recycled bottles in the US this year. PepsiCo is introducing them in Europe.

Whether companies will meet their goals—more than doubling in most cases their use of recycled resin in a few short years—is possibly the most important question facing the plastics industry today. Given decades of glacial progress, many observers are not confident that they will.

“There has been this history of making big, grand promises on recycling and not following through,” says Conrad MacKerron, senior vice president of As You Sow, an organization that prods big corporations on environmental performance.

For instance, according to an As You Sow study, Coca-Cola set a goal of 25% recycled content in the early 1990s, only to abandon it in 1994. The company unveiled a new target in 2011 of incorporating 25% recycled or renewable content by 2015 but achieved only 12.4%.

PepsiCo had a goal of 50% recycled content in its containers by 2018 that it quietly abandoned. The company later set a target of 25% recycled content by 2025. Just last month, the firm tweaked its goal again, raising its target to 50% while pushing the deadline to 2030.

But times may have changed. MacKerron says those previous missed goals were set before plastics became the hot topic they are today. “It was more of a back-burner issue, and we were working on it, but not a lot of groups were working on it,” he says. And, MacKerron notes, companies are more open to collaboration than they were in the past, when sustainability initiatives were largely internal.

Moreover, companies realize they must invest significantly to achieve recycling goals. Nestlé, for example, has allocated $1.6 billion to pay premiums for recycled material over virgin plastics. Nestlé aims to motivate recyclers and waste management companies to expand their operations.

“If there is no demand, then no one is going to recycle, which is going to add to the plastics waste challenge,” says Evan Arnold, vice president of business development at Glenroy, which makes flexible packaging for clients such as Costco Wholesale. Earlier this year, Glenroy launched a line of stand-up pouches, which boast 48% recycled resin content, for food and personal care products.

“We really have to be the one that stands up and says, ‘Yeah, we’ll utilize this,’ ” Arnold says about recycled resin. “We’ll explain to our customers the benefits of using this and face the challenge of using recycled products head-on.”

Passing the quality bar

One of the biggest challenges for consumer product companies is procuring enough of the high-quality resins they need for containers that contact food and beverages. These plastics are a cut above the recycled plastics used for carpet fiber or detergent bottles in terms of purity and performance.

The US Food and Drug Administration has issued guidelines on recycled resins for food packaging and sends letters of no objection to companies that meet them. Recyclers must, for example, demonstrate that only food-contact containers enter their process. The FDA recommends recyclers subject their operations to surrogate contaminant testing, in which plastics are spiked with chemicals like chloroform or toluene to see how well they are removed. Ultimately, the aim is to keep residue levels below 200–300 µg/kg.

The FDA has issued more than 250 of the no-objection letters for food-packaging plastics in recent years, mostly for products containing PET. That resin is recycled more than other plastics, with a US recycling rate of 28%, according to the National Association for PET Container Resources. But that number hasn’t moved much for years and lags behind the global figure of 50%. Moreover, only about 28% of recycled bottles become food and beverage containers again. The rest are downcycled into products like carpet fiber and strapping used to tie lumber together.

Jon McNaull, vice president of resins for DAK Americas, an Alpek Polyester business and the largest virgin-PET producer and recycler in the Americas, says PET naturally lends itself to recycling because it is resilient and less likely than other polymers to break down while being re-formed into finished goods. And any breakdown can be reversed through solid stating, a process in which the polymer is heated to just above its glass-transition temperature so its chains react and build molecular weight.

“You can create a consumer product beverage container, and you can send it to the consumer, and you can bring it back, and you can put it through this industry and make it back into a suitable, safe consumer container again,” McNaull says.

A lot goes into that transformation, explains Srinivasan Prabhushankar, CEO of recycling for Indorama Ventures, the world’s largest PET maker and recycler. Indorama buys bottles that have been collected at curbsides or through local deposit systems. Workers remove errant metals, paper, non-PET containers, and even PET containers that are tinted brown or green. The PET is then chopped into flake and washed.

Such flake, at this point, might be good enough for strapping or carpet fiber. But to meet the FDA’s food-contact guidelines, it needs more treatment. Indorama scans the flake with infrared light that helps machinery identify the remaining contaminants—for instance, bits of off-color PET that previously escaped notice.

The flake is then melted. A near vacuum of about 1 mbar of pressure is applied to the molten resin to suck up any remaining volatile compounds. The resin is also filtered to remove microscale particles. Solid stating builds up the molecular chains until the PET has the right viscosity for bottles again. Every Indorama plant has a quality-control lab where resin samples are collected frequently and analyzed in gas chromatographs, mass spectrometers, and other instruments.

The process is expensive, Prabhushankar says. Brand owners are willing to pay more for the recycled PET, but recycling still doesn’t make money. “They are only compensating us for the cost that we incur,” he says. “There are many recyclers who are unable to continue.” Case in point, he notes, is the high-end PET recycler CarbonLite, which was liquidated recently and sold to competitors.

Two of those competitors were DAK and Indorama, both of which are plunging increasingly into PET recycling in a bid to be one-stop shops that offer virgin resin, recycled resin, and blends to an increasingly environmentally conscious clientele. “Our customers’ requirements change, and we are going to modify our capital expenditures and our strategy to service their needs,” McNaull says.

DAK has nearly 400,000 metric tons (t) per year of recycling capacity, some of it from a CarbonLite plant it bought in Reading, Pennsylvania. Of that capacity, some 120,000 t goes into pellets for food and beverage containers. The company aims to make recycled PET 25% of its sales by 2025.

Indorama plans to spend $1.5 billion on recycling to reach a goal of annually recycling about 50 billion bottles—representing about 750,000 t of PET—by 2025. To further this goal, the company bought a CarbonLite plant in Dallas. That purchase, along with other expansion projects, should bring the company to half its objective by next year, Prabhushankar says.

Recycling polyolefins for food-contact applications is even more challenging than recycling PET largely because those plastics are used in a much wider variety of packaging.

Troy, Alabama–based KW Plastics is the world’s largest recycler of polypropylene and high-density polyethylene. The company has 250,000 t of annual capacity and is expanding by 65%.

It is also one of only a handful of US polyolefin recyclers to receive a letter of no objection from the FDA. Meeting the agency’s standards is a multistep process, according to Scott Saunders, KW’s general manager. Workers start by thoroughly inspecting the bales of plastic that arrive from materials recovery facilities. The firm can process yogurt containers, for example, but must remove the non-food-contact items like kitty-litter buckets and shampoo bottles.

KW carefully shreds and washes the containers and, like the PET recyclers, applies a vacuum to molten resins to remove volatile compounds. It then adds colorants, antioxidants, and other food-contact additives to meet customer specifications.

KW’s products don’t go into food packaging but rather personal care containers like shampoo bottles and deodorant sticks, for which its customers in consumer products want a high-purity polymer with food-grade quality. Saunders worries that selling into actual food-contact markets might expose his firm to liability.

And business in the personal care segment, which KW serves, is booming. Not long ago, Saunders says, KW’s material was sold as a low-cost alternative to virgin plastics. Now big brands are clamoring for high-end polyolefins. “In 2014 or 2015, we couldn’t get an audience with a lot of consumer product companies,” he says. “Today we know all of them.”

The solvent solution

If high-volume recycling has been difficult to achieve for PET and polyethylene, it has been nearly impossible for polypropylene and polystyrene. Solvent extraction could solve this problem.

The most prominent practitioner of solvent recycling is PureCycle Technologies, which is trying to turn polypropylene recycling around. Polypropylene is one of the most ubiquitous polymers, found in soft-drink cups, face masks, and car bumpers. But only 1% of polypropylene is recycled, according to the American Chemistry Council. Many municipalities don’t even bother to collect it.

It is polypropylene’s very versatility that hinders its recycling, says Dustin Olson, PureCycle’s chief manufacturing officer. “The reason it isn’t getting recycled at a higher rate is because of the various applications that it’s in,” he says. Each of them requires its own set of dyes, fillers, impact modifiers, and other additives.

A consumer product company, Procter & Gamble, developed PureCycle’s process in the early 2010s. In a presentation last November, John Layman, director of sustainable materials development at P&G, said the company uses polypropylene more than any other plastic—for example, in items like toothbrush and razor-blade handles, nonwoven fabrics, and container caps. P&G, he said, is also a cleaning specialist, which led its technologists to wonder: “Can we put our powers of cleaning to work on cleaning recycled resins?”

The process it developed uses supercritical butane to dissolve polypropylene. Olson says PureCycle plays with temperature and pressure so pure polypropylene precipitates out of the solvent and leaves contaminants behind. “What we are doing is dry-cleaning the molecules,” he says.

PureCycle went public earlier this year by merging with a special purpose acquisition company. PureCycle is building a plant in Ironton, Ohio, that will have about 50,000 t of annual capacity when it opens next year. The company plans to spend $440 million on a much larger plant, in Augusta, Georgia. With local partners Mitsui & Co. and SK Geo Centric, it is studying operations in Japan and South Korea as well.

Solenne Brouard Gaillot, CEO and founder of Montreal-based Polystyvert, has a similar ambition for polystyrene, another notoriously difficult-to-recycle resin with a US recycling rate that also hovers around 1%, according to the EPA.

Polystyvert’s technology uses p-cymene, a solvent with a particular affinity for polystyrene. After dissolving the polymer and filtering out contaminants, the firm precipitates it by adding heptane.

In June, Polystyvert completed an investment round that included the European packaging firm BEWI. Brouard Gaillot won’t say how much money Polystyvert raised, but she says it is enough to build the company’s first commercial-scale plant, a 10,000 t unit in Montreal. “We can use it as a showcase to license the technology,” Brouard Gaillot says.

The environment for new recycling technology is better than it has ever been. Like others, Brouard Gaillot contends that interest by consumer product companies and the public is bringing constructive change.

“I started the company 10 years ago, and at the beginning, I had to explain why it’s important to recycle. People were not ready to put money on the table,” she says. “Now the demand for recycled polystyrene is very high, and it’s more expensive than virgin. That’s a speedy evolution.”

Big challenges remain

But improving plastics recycling will take more than just new technology and the willingness of consumer product companies to buy more recycled resin. Plastics recyclers say two big advances are needed if the recycling rate is to increase appreciably: a vast expansion in collection and easier-to-recycle plastic goods.

PET firms see the main bottleneck as the collection step. “We will expand our business to the extent we can get bottles to support the expansion, but collection expansion is key,” DAK’s McNaull says.

Indorama’s Prabhushankar says people often don’t have the options, or the motivation, to dispose of their bottles responsibly. “Consumers are not fully educated on the value of the bottles that they have,” he says. “If they make the wrong choice and put the bottle in the trash bin, then it’s gone. That one decision point decides the entire fate of the bottle.”

Bottle deposit systems, where people get a monetary incentive to bring their bottles back to the store, help, but only 10 of the 50 US states have them. In California, which has a deposit system, the collection rate is nearly 70%, Prabhushankar says. In Alabama, which has no deposit or even curbside collection in some places, it is less than 10%.

In a 2020 report, the Recycling Partnership says only 32% of the 37.4 million t of commodities of all kinds that could be recycled annually in the US actually are. Only 52% of US households participate in curbside recycling programs, either because they aren’t available or because people aren’t using them. The report says $9.8 billion in investment is needed to close the gap.

Experts agree that collection is the rate-limiting step of the entire recycling system. For example, KW’s Saunders says that the US recycling rate for high-density polyethylene bottles—the kind used for milk and detergent jugs—is currently 28%. But it could be doubled through additional collection, without new processing plants.

“The low-hanging fruit is to maximize the capacity of what’s already installed,” Saunders says. “And to do that as an industry and a country and a society, we’ve got to convince people that have that container in their hand to put it in a recycling bin somewhere and not in the trash.”

But Saunders has noticed changes for the better. “We’ve seen a tremendous amount of investment happening in sortation,” he says. “We’re seeing growth in the material, and we’re seeing the quality improve.”

Further improvement, advocates say, will require consumer product makers to redesign their packaging so it is easier to recycle in today’s mechanical systems. In one example of designing for recycling, Unilever modified the black plastic used in its Axe deodorant and TRESemmé hair care brands so they are detected by optical scanners. PepsiCo is eliminating the green tint in its 7Up bottles in Europe. Danone is selling its Evian water in France with no label at all.

Keurig Dr Pepper transitioned its coffee pods from styrenic resins to polypropylene. And the company has been working with AMP Robotics so the new pods will be recognizable to the artificial intelligence machines. Many more, and varied, collaborative efforts will be needed to make a dent in recycling, Writz says. “To make more packaging truly recyclable, you have to work on different aspects of the supply chain.”

And more design for recycling is needed to reverse momentum that for decades has made plastic goods complicated and difficult to recycle. For example, brands and stores love multilayer packaging for colorful, stand-up pouches, but the multiple plastics and metallized layers they involve make them tough to recycle.

Glenroy’s Arnold says 95% of his firm’s technical development time is spent tackling such problems and advising clients to adopt simpler packaging. “If the brand feels much safer with a metallized option, even if it isn’t needed, they would have probably in the past leaned that way just to have the extra protection,” he says. Now, brands are seeing that they can have sufficient protection in a simpler, nonmetallized, more sustainable material, he says.

Steve Alexander, president of the Association of Plastic Recyclers, a trade group, says consumer product firms need to recognize that in a circular economy, they are their own raw material suppliers. “You cannot create a supply of recycled resin if you’re contaminating the very stream of material you want the recycling community to create,” he says.

Chemical recycling offers itself as a different solution to the multimaterial problem. Chemical recycling, especially pyrolysis, is billed as a technology that can break down whatever plastic is fed into a reactor into basic molecular building blocks. But Alexander fears this yet-to-be-realized promise will give consumer product companies an excuse not to design their packaging for mechanical recycling.

Alexander sees chemical recycling as a complement to the current incumbent. “The collection infrastructure we have in this country, and how recycling programs work, is always going to be mechanical recycling. Where chemical recycling fits in is taking those materials that are not appropriate for mechanical recycling,” he says. He’d like to keep that category to a minimum.

And veterans of mechanical recycling are skeptical that chemical recyclers will ever achieve what they have been doing, day in and day out, for decades. “If somebody builds a chemical plant and they can take a variety of resins blended together in a bale and deal with 20% contamination by rocks, dirt, glass, paper, chicken bones—all the things that we deal with—I’ll be a big cheerleader of that,” Saunders says.

Until then, he says, the recycling industry should make the system it has now work better.