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British Food Journal

ISSN : 0007-070X

Article publication date: 23 July 2021

Issue publication date: 8 February 2022

This paper presents a comprehensive overview of the cross-disciplinary literature on the drivers, barriers and performance outcomes of sustainable packaging to understand the current state of research in this field and identify research opportunities.

Design/methodology/approach

A systematic review is conducted within no time limit. The Methodi Ordinatio methodology was applied that resulted in retaining 48 relevant and high impact articles published in 26 academic journals with various scopes.

Seven key drivers are identified and defined: the integrative and collaborative supply chain, environmental capabilities and resources, market-based instruments, cost reduction, consumer pressure, competitive advantage, and regulatory pressure. Three main barriers are identified and defined: cost/benefit ambiguity, additional costs and complex trade-offs between packaging requirements. The review shows that the drivers and barriers to packaging sustainability are contingent on the firm size. Sustainable packaging positively affects the environmental, social and economic performance; however, its operational performance requires a proactive and integrated supply chain. The results highlight the importance of integrated packaging decisions at three different levels to improve packaging sustainability: vertical and horizontal integration, upstream and downstream integration, and product-packaging integration. The authors developed research propositions and provided insightful directions for future research.

Originality/value

Most studies focus on specific drivers, barriers and outcomes of sustainable packaging, while this paper brings them together to build a comprehensive framework. The latter provides a deeper understanding of the factors that incentivize or deter firms from pursuing sustainable packaging and its performance outcomes.

• Sustainable packaging
• Performance outcomes
• Systematic literature review

Acknowledgements

The authors would like to thank the anonymous reviewers and the editor of British Food Journal for their valuable suggestions and comments on earlier drafts on this paper.

Funding : Doctoral Fellowships, Social Sciences and Humanities Research Council (SSHRC), Grant Number/Ref. CRSH: 752-2020-1649. Insight Development Grants, Social Sciences and Humanities Research Council (SSHRC).

Afif, K. , Rebolledo, C. and Roy, J. (2022), "Drivers, barriers and performance outcomes of sustainable packaging: a systematic literature review", British Food Journal , Vol. 124 No. 3, pp. 915-935. https://doi.org/10.1108/BFJ-02-2021-0150

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Sustainability in packaging 2023: Inside the minds of global consumers

Sustainability continues to be an increasingly important issue for the packaging value chain. At the same time, consumer awareness is also growing. As societies emerge from the COVID-19 pandemic, consumer sentiment is evolving away from a hyperfocus on hygiene. To understand this better, we launched a survey across 11 countries to explore consumers’ attitudes toward sustainable packaging. This builds on our 2020 work focusing on consumer sentiment globally, 1 “ Sustainability in packaging: Inside the minds of global consumers ,” McKinsey, December 16, 2020. as well as our 2023 work related to consumer sentiment in the United States. 2 David Feber, Abhinav Goel, Daniel Nordigården, and Suku Ponkshe, “ Sustainability in packaging: US survey insights ,” McKinsey, April 26, 2023.

About the authors

Our 2023 survey covers a statistically significant sample size across 66 percent of global GDP and 50 percent of the global population, as well as across demographics in each of the 11 countries. Responses from more than 11,500 consumers reveal three main findings. First, across all countries, hygiene and shelf life top the list of factors important in consumers’ purchasing decisions. Second, on the environmental impact of product packaging, consumer concerns related to ocean litter are most evident in Europe, Japan, and the United States. Meanwhile, consumers in other Asian countries and Latin America seem most concerned about other forms of pollution. And finally, consumers around the world have different opinions on what type of packaging is most sustainable. That said, there is agreement on what the least-sustainable options are.

As this survey shows, it is clear that packaging companies will need to tailor their approaches to respond to an evolving and varied consumer landscape. In this article, we suggest five critical questions they will need to answer while building their future strategies.

Post-COVID-19 trends in packaging sustainability

In the early stages of the pandemic, hygiene concerns paused the drive to eradicate single-use packaging across several regions. 3 For full details, see David Feber, Oskar Lingqvist, and Daniel Nordigården, “ Shaping the next normal of packaging beyond COVID-19 ,” McKinsey, May 26, 2020. However, we are now seeing a shift away from this. The majority of consumers are less concerned about hygiene and food safety than they were during the pandemic, even though their level of concern is still above where it was before COVID-19 pandemic (Exhibit 1).

Nevertheless, even with the significant reductions of COVID-19 concerns, consumers still prioritize hygiene and food safety and shelf life as the two most important aspects of product packaging (Exhibit 2).

Similar to 2020, 4 For more on the results of the 2020 survey, see “ Sustainability in packaging: Inside the minds of global consumers ,” McKinsey, December 16, 2020. price and quality continue to be most important for consumers when making a product purchasing decision. Compared to 2020, overall price has become even more important as a decision criterion, up 11 percent. In developed nations such as France, Germany, Italy, Japan, Sweden, the United Kingdom, and the United States, price as a decision criterion has climbed by double digits. By comparison, price is still significant in developing nations such as Brazil, China, India, and Mexico, but its importance has risen by low to mid-single digits compared to 2020.

The future of sustainability in packaging

As time moves on from the outbreak of COVID-19, sustainability pressure is building once again. Manufacturers and retailers of fast-moving consumer goods continue to innovate new packaging formats to improve circularity, particularly focusing on recycled content such as post-consumer resin. These innovations come as players seek to deliver on their own sustainability commitments and address consumer expectations, nongovernmental organization voices, and new packaging regulations.

Currently, new regulation governing sustainability dimensions of packaging is expanding on multiple fronts such as proportions of recycling or recycled content and is no longer confined to select countries or regions. As a result, these regulations have become more of a global phenomenon, even if their levels vary. However, exactly what consumers are concerned about in terms of environmental impact differs, depending on region (Exhibit 3).

Consumers in developing economies, especially China, Brazil, and India, are more concerned about both air and water pollution, while ocean litter is top of mind for most consumers in Europe, Japan, and the United States.

In all surveyed countries and across end-use areas, the majority of respondents claim to be willing to pay more for sustainable packaging, although willingness to pay more for packaging is much higher in developing nations. Willingness to pay is highest in the fresh fruit or product and fresh meat or poultry categories. In most countries, higher-income groups have a greater willingness to pay for sustainable-packaging offerings compared to the same product with nonsustainable packaging.

In Europe, better product labeling and rebate or incentive programs could encourage consumers to buy more products with sustainable packaging; in some other countries, increased availability of sustainable products and improved pricing could encourage consumers to buy packaging that is more sustainable. Accordingly, companies can continue to pursue a nuanced approach, remaining flexible about the sustainability levers deployed within each country.

Packaging substrates: What do consumers prefer globally?

Our recent research on packaging and sustainability shows that no single packaging type (whether plastic, glass, metal, or paper) is an absolute leader across every attribute of packaging sustainability. All types have both positive and negative features that vary in terms of sustainability, application, and region. Still, the question often asked is which packaging substrate is seen as the most sustainable by consumers. Our survey indicates consumers around the world are not fully aligned in their views on what the most sustainable packaging materials might be (Exhibit 4):

• Compostable and plant-based packaging (for example, sugar cane and cornstarch) tends to rank higher in several countries, with the exception of Japan. In Japan, consumers view plastics made from recycled content or fully recyclable plastics as being equally sustainable as compostable packaging.
• Globally, plastic films made from renewable or compostable material also rank high.
• Paper scores high on average and especially high in countries such as India and the United Kingdom.

Five critical questions to consider

We suggest that packaging suppliers and consumer companies take a strategic look at their portfolios, being careful to assess them in the context of five critical questions:

• What are unique generational trends that can affect products over the next five to seven years?
• Which products are most at risk based on anticipated regulatory changes and consumer perception?
• What innovation and disruption are being pursued by competitors and innovators across key product areas?
• What are the potential growth opportunities in which the company would be uniquely positioned to provide winning solutions regarding sustainability and circularity?
• What are the nuances across demographics that can help better align products to end-market segments?

Consumer sentiments have been shifting as the world emerges from the COVID-19 pandemic, and in some cases, these are continuing to diverge across countries, regions, and demographics. In this rapidly evolving landscape, companies can develop nuanced strategies to help create growth opportunities and to emerge as winners.

David Feber is a senior partner in McKinsey’s Detroit office, Abhinav Goel is a partner in the Pittsburgh office, Daniel Nordigården is a partner in the Toronto office, Suku Ponkshe is an associate partner in the Atlanta office, and Mukund Prasad is a partner in the Toronto office.

The authors wish to thank Audrey Gotko, Felix Gruenewald, Lucas Menanix, Emily Roeper, Matthew Seidner, Lizzie Shilko, and Binghong Xie for their contributions to this article.

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Paper-based Packaging Has a Great Sustainability Story

Built around comedian and actress Retta, the Go Papertarian! initiative is getting consumers to think about product packaging both before purchase and at the point of sale. Image Courtesy of The Paper and Packaging Board.

It Deserves Great Storytellers

By Mary Anne Hansan, president of the Paper and Packaging Board (P+PB)

In 2014 the U.S. Department of Agriculture put a question to U.S. manufacturers and importers of paper and paper-based packaging: should they join forces to help market and educate consumers about a great American natural resource?

The Paper and Packaging Board exists because they said “yes.”  Three times. 

Today, our consumer campaign is about sharing paper and packaging’s environmental story that is especially important in a world where more people than ever are concerned about doing the right thing for the planet.

Our campaign messaging is informed by careful research and close collaboration with our Board.

We know, for instance, that 84% of our most important consumer segment — we call them “Expressives” because they are united by their way of seeing the world as opposed to any particular demographic characteristic — are increasingly concerned about consumption of paper and paper-based packaging. In short, they feel guilty about waste.

But we also know their guilt is fueled by misunderstandings. In fact, 58% of these consumers incorrectly think forests are shrinking, not growing; and 61% think this natural resource is “fragile,” when it’s actually one of the most robust and replenishable resources on earth.

Focusing on sustainability

Still, there is good news, and a reservoir of good will for us to tap. Three out of four Expressives feel positively about our industry and products, and they prefer paper-based products over plastics by a two-to-one ratio. We can and must build on this.

Our latest research shows that we are building on it. It shows that when consumers learn the facts about our industry’s sustainability practices, they feel better about the industry.

And here is where a dogged focus on sustainability translates into an increase in consumer preference: when people feel like they are part of the environmental solution by choosing paper products, their likelihood of consuming them increases. Simply put, they feel good about what they’re buying, so they buy more.

We’ve also learned how to move the dial by connecting our industry and product sustainability benefits to consumer values and aspirations. We’ve pinpointed the specific language and messages that work. And with that roadmap in hand, our campaign has already begun telling a powerful sustainability story at a scale, the way only we can.

And while we always seek to highlight both paper and packaging, there’s no question that packaging—and sustainable packaging innovations in particular—are at the core of all our work.

The Future of Recycling video showcases high-tech recycled paper mills, where piles of ordinary household garbage are turned into useful new products. Image courtesy of P+PB.

P+PB initiatives

We’re promoting multiple initiatives, along with other supporting materials, across multiple channels, including traditional television, cable, streaming, paid digital channels, magazines, podcasts, social media, and the campaign’s own HowLifeUnfolds  website. Here’s some of the highlights:

The centerpiece,  Go Papertarian!  Initiative, built around comedian and actress Retta, is getting consumers to think about product packaging both before purchase and at the point of sale. Our spots see Retta at work, home, and the grocery store, pointing out the sustainable virtues of paper and paper-based product packaging, and using humor to gently correct underinformed foils, like her intern and neighbors, about the proper ways to recycle — all the while showcasing the industry’s impressive diversity of products.

PackIt! The Packaging Recycling Design Challenge  has contestants compete to design recyclable product packaging from the ground up in 10 hours, with a $5,000 prize for the winner.

The  Box to Nature  residential recycling labeling initiative includes a persuasive recycling reminder brands can use on all kinds of boxes. And, we have multiple partnerships with recycling influencers showing consumers how to become “super recyclers.”

The  Future of Recycling video  showcasing the newest, biggest and most high-tech recycled paper mills in North America from Graphic Packaging in Kalamazoo, Michigan; and a bold and potentially game-changing experimental facility from Georgia-Pacific in Toledo, Oregon, where a paper company’s recycling is not just paper and boxes but turning piles of ordinary household garbage into useful new products.

What’s next?

We’re hard at work thinking up the next iteration of our story, to ensure both that consumers continue to say “yes” to paper-based packaging and products, and to make sure that our industry says “yes” the next time they’re asked whether we are delivering on our promise to them.

This moment needs products with a great sustainability story. And that story deserves great storytellers.

About the Author As President of the Paper and Packaging Board (P+PB), Mary Anne Hansan leads P+PB’s How Life Unfolds® national consumer and B2B marketing campaign, reaching millions of consumers each year. The campaign, collectively funded by 46 manufacturers and importers, promotes the use of paper products and paper-based packaging by highlighting how their sustainable nature, the industry’s practices and recycling help contribute to a healthier planet. Learn more at www.paperandpackaging.org .

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This review article provides a thorough overview of barrier coating materials that have been used in food packaging with a focus on biodegradable (bio-based or petroleum-based) materials, such as lipids, proteins, polysaccharides, agriculture waste and polyesters. The goal is to provide an opportunity to acknowledge progress made in this field, focusing on modifications made to coatings. These modifications aim to address the shortcomings of biodegradable substrates (either plastic or paper) and improve their performance, enabling them to compete with traditional petroleum-based food packaging materials. This includes their barrier against water vapor and oxygen, mechanical and surface characteristics (sealability and adhesion), as well as antimicrobial properties. The barrier of most biodegradable polymers underperforms in comparison with petroleum-based non-biodegradable polymers, which possess either high water vapor barrier or high oxygen barrier. Coating technology is a promising solution particularly in barrier improvement of biodegradable polymers. Currently, there are only metallized, or inorganic nanosheet coatings available for biodegradable films that meet food packaging requirements. There are some challenges in this field, for example, being able to retain the coating's biodegradability despite applied modifications to improve it's performance, the large-scale fabrication of biodegradable coatings, the coating's delamination and heat-sealability during service time, and the migration of the coating into the packaged food. Moreover, green chemistry and its sustainability needs in biodegradable polymeric coatings are also discussed regarding new ideas and possible directions for widespread application of coatings in food packaging. This is the first review that specifically summarizes biodegradable coatings on plastic and paper substrates with a focus on coating modifications to improve the performance of the base substrate to meet the required properties for food packaging applications.

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$1.6M donation will accelerate progress within the pulp and paper industry

Packaging Corporation of America (PCA) has donated $1.6 million to the University of Maine to establish the UMaine Sustainable Packaging Initiative. 

The UMaine Sustainable Packaging Initiative is a research-based public and private consortium that focuses on using forest-based materials to accelerate the transition to renewable and recyclable packaging made from forest fiber. 

“As a UMaine graduate, I am happy to be part of PCA’s involvement in the UMaine Process Development Center. This investment will enable the PDC to expand research and development activities and industry support to include packaging grades. Sustainable packaging represents a huge potential for the paper industry; it is exciting to be a part of this change both as a PCA employee and a UMaine advocate,” said Barbara Hamilton, senior director of process control technology at PCA.

PCA’s donation will support the university’s Process Development Center (PDC). The PDC is a unique, open-access research facility that offers research and development technical services and resources in traditional pulp and paper, as well as emerging process technologies and material science. Funds will provide infrastructure improvements and new equipment to foster growth in becoming the leading R&D/pilot production lab for renewable packaging in the U.S.  

“This gift is transformative for the PDC,” said center Director Colleen Walker. “Not only will the PDC be better able to serve company and university researchers developing and commercializing new forest-based solutions for packaging, but we are engaging our Black Bear students in this process to provide hands-on research learning experiences.”

PCA’s donation will also help leverage the $75 million matching challenge grant from the Harold Alfond Foundation to support the Maine College of Engineering and Computing, a signature initiative of UMS TRANSFORMS . The initiative is focused on attracting thousands of new engineering and computing students to the state and expanding educational opportunities in emerging fields such as artificial intelligence, renewable energy and advanced materials. The Maine College of Engineering and Computing is a statewide, integrated solution to providing the technical workforce and innovations critical to moving Maine’s economy forward and improving R&D for state-based industry.

“We are grateful to PCA for this generous gift that will allow the continued support of research and innovation at the University of Maine,” said UMaine President Joan Ferrini-Mundy. “This gift will position us as a world leader in sustainable packaging, as well as offer research learning opportunities to current and future students.”

PCA is a long-time supporter of UMaine through the UMaine Pulp and Paper Foundation. The foundation supports aspiring engineers who are interested in pursuing careers in the paper industry. 

“The UMaine Pulp and Paper Foundation’s students have long benefitted from the extraordinary vision of PCA and its CEO and Chairman, Mark Kowlzan,” said UMPPF President Carrie Enos. “We are proud to connect PCA with our partners at the PDC as the University of Maine continues to build its reputation as a leader in cutting-edge uses for forest fiber.”

PCA’s donation is just one of several investments recognizing the leadership of the state and UMaine in the national forest sector. In October, Maine was designated a Forest Bioproducts Advanced Manufacturing Tech Hub by the Biden-Harris Administration through the U.S. Department of Commerce’s Economic Development Administration. In March, U.S. Sen. Susan Collins, vice chair of the Senate Appropriations Committee, and U.S. Sen. Angus King announced they had secured $10 million in one-time Congressionally Directed Spending to build and equip the Forest Biomaterials Innovation Center , an extension of the existing UMaine Process Development Center, to enable researchers and entrepreneurs to develop new forest-based products utilizing wood and wood residuals. These investments represent many of the recommendations from FOR/Maine to create jobs and economic opportunities for Maine’s forest economy and rural communities. 

Contact: Shelby Hartin, [email protected]

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So Much Produce Comes in Plastic. Is There a Better Way?

As governments impose limits on plastic food packaging, climate-friendlier alternatives are in the works. Here are some that might be coming to a grocery store near you.

By Kim Severson

If it seems like plastic surrounds nearly every cucumber, apple and pepper in the produce aisle, it does.

What began with cellophane in the 1930s picked up speed with the rise of plastic clamshells in the 1980s and bagged salads in the 1990s. Online grocery shopping turbocharged it.

But now the race is on for what people who grow and sell fruits and vegetables are calling a moon shot: breaking plastic’s stranglehold on produce.

In a March survey among produce professionals on LinkedIn, the shift to biodegradable material was voted the top trend . “It’s big,” said Soren Bjorn, chief executive officer of Driscoll’s, the world’s biggest grower of berries, which has switched to paper containers in many European markets.

Spain has a plastic tax. France has severely limited plastic-wrapped produce and the European Union is about to add its own restrictions . Canada is trying to hammer out a plan that could eliminate plastic packaging of produce by 95 percent by 2028. In the United States, 11 states have already restricted plastic packaging. As part of a sweeping anti-waste plan, the Biden administration is calling for new ways to package food that uses climate-friendly, antimicrobial material designed to reduce reliance on plastic.

So we agree that eliminating plastic is the answer?

Reducing the use of plastic is an obvious way to push back against a changing climate. Plastic is created from fossil fuels, the biggest contributor to greenhouse gases . It chokes the oceans and seeps into the food chain. Estimates vary, but about 40 percent of plastic waste comes from packaging.

Yet plastic has so far been the most effective tool to fight another environmental threat: food waste.

Wirecutter shares tips for keeping your produce fresh for weeks.

Selling produce is like holding a melting ice cube and asking how much someone will pay for it. Time is of the essence, and plastic works well to slow the decay of vegetables and fruit. That means less produce is tossed into the garbage, where it creates almost 60 percent of landfill methane emissions, according to a 2023 report by the Environmental Protection Agency.

A Swiss study in 2021 showed that each rotting cucumber thrown away has the equivalent environmental impact of 93 plastic cucumber wrappers.

Food is the most common material in landfills. The average American family of four spends $1,500 each year on food that ends up uneaten. Of that, fruits and vegetables make up nearly half of all household food waste, according to research from Michigan State University. And it’s not just the wasted food that adds to climate change. The farming and transportation wasted to produce food that is discarded impacts the climate, too.

Preventing food waste and reducing the use of plastic aren’t mutually exclusive goals. Both are high on the agenda of the Biden administration, which in December issued a draft of a national strategy to halve the nation’s food loss by 2030.

Are Americans on board?

Consumers increasingly report that using less plastic and packaging matters to them, but their shopping habits tell a different story. American shoppers bought $4.3 billion worth of bagged salad last year, according to the International Fresh Produce Association. Marketing experiments and independent research both show that price, quality and convenience drive food choices more than environmental concerns.

Grocers are having to make tough decisions, too. Shoppers have complained about having to buy produce that has already been packed in plastic and priced. Not selling by weight is easier for the store, whose workers don’t have to weigh each item. But it often forces shoppers to buy more than they need.

Battle lines seem to be drawn between the never-plastic crowd and shoppers who prefer the ease of fresh salad greens delivered to their door.

“The packaging conversation is being held hostage by one side or the other,” said Max Teplitski, chief science officer of the International Fresh Produce Association. He leads the Alliance for Sustainable Packaging for Foods , a collection of industry trade groups that formed in January.

The group’s priority is to make sure that any changes in packaging will keep food safe and preserve its quality.

What alternatives to plastic are coming?

Here are a few new ideas headed to the produce aisle:

Bags from trees. An Austrian company is using beechwood trees to make biodegradable cellulose net bags to hold produce. Other companies offer similar netting that decomposes within a few weeks.

Film from peels. Orange peels, shrimp shells and other natural waste are being turned into film that can be used like cellophane, or made into bags. An edible coating made from plant-based fatty acids is sprayed on cucumbers, avocados and other produce sold at many major grocery stores. They work in a way similar to the wax coating commonly used on citrus and apples.

Clamshells from cardboard. Plastic clamshells are a $9.1 billion business in the United States, and the number of growers who use them is vast. Replacing them will be an enormous challenge, particularly for more fragile fruits and vegetables. Plenty of designers are trying. Driscoll’s has been working to develop paper containers for use in the United States and Canada. In the meantime, the company is using more recycled plastic in its clamshells in the United States.

Ice that feels like gelatin. Luxin Wang and other scientists at the University of California, Davis, have invented reusable jelly ice . It is lighter than ice and doesn’t melt. It could eliminate the need for plastic ice packs, which can’t be recycled. After about a dozen uses, the jelly ice can be tossed into a garden or the garbage, where it dissolves.

Boxes with atmosphere. Broccoli is usually shipped in wax-coated boxes packed with ice. The soggy cartons can’t be recycled. Iceless broccoli shipping containers use a mix of gases that help preserve the vegetable instead of chilling it with ice, which is heavy to ship and can transmit pathogens when it melts. Other sustainable, lighter shipping cartons are being designed to remove ethylene , a plant hormone that encourages ripening.

Containers from plants. Rice-paddy straw left over after harvests, grasses, sugar cane stalks and even food waste are all being turned into trays and boxes that are either biodegradable or can be composted.

Problem solved, right?

Hardly. Even if every grower and grocer started using packaging that could be recycled or composted, America’s infrastructure for turning it into something besides trash is spotty at best. Less than 10 percent of all plastic is recycled, a figure that is even lower for produce packaging, said Eva Almenar , a professor at Michigan State University’s School of Packaging . Only a small fraction of packaging labeled compostable stays out of the landfill.

Just 3 percent of wasted food lands at industrial composting centers. Several states have no commercial operations that can compost food waste.

“We don’t have right the technology, and we don’t have the collection systems,” Dr. Almenar said.

Even if the infrastructure were in place, people’s habits aren’t. “Consumers have no clue about what means green, compostable or recyclable,” she said.

Practically, no one has yet devised an affordable plastic alternative that can be recycled or composted and also keeps fruits and vegetables safe and fresh. Plastic allows packers to modify the mix of gases inside a package in a way that extends the shelf life and the quality of fresh produce.

“The pushback you are getting is that if you eliminate plastic and go to fiber, it depletes the shelf life really fast,” said Scott Crawford, vice president of merchandising for Baldor Specialty Foods and a veteran of both Whole Foods Market and Fresh Direct. “The question is which side of the balloon are you trying to squeeze?”

The ideal solution, he said, would be to go back to the days before plastic, when grocers stacked their produce by hand and no one demanded that seasonal fruit like blueberries be available year-round.

“I don’t think we’re going to live to see that,” he said.

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• Environment

Amazon Is Capable of Reducing Plastic Waste in the US. So Why Isn’t It?

It has done so elsewhere—when forced, a new report shows., joseph winters.

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Lea Suzuki / The San Francisco Chronicle via Getty Images via Grist

This story was originally published by  Grist   and is reproduced here as part of the  Climate Desk   collaboration.

In response to growing pressure to address the plastic pollution crisis, Amazon has been cutting down on plastic packaging. Last July, the company said it used  11.6 percent less plastic for all of its shipments globally in 2022, compared to 2021. Much of Amazon’s reductions took place in countries that have enacted—or threatened to enact—restrictions on certain types of plastic packaging. But the company’s progress may not extend to the US, which has not regulated plastic production on a federal level. 

Amazon generated 208 million pounds of plastic packaging trash in the United States in 2022, about 10 percent more than the previous year, according to a new report from the nonprofit Oceana. This packaging includes Amazon’s ubiquitous blue-and-white mailers, as well as other pouches, bags, and plastic cushioning. If all of it were converted into plastic air pillows and laid end to end, Oceana estimates it would circle the Earth more than 200 times.

“The crisis is so significant that we need change now,” said Dana Miller, Oceana’s director of strategic initiatives and an author of the report.

Miller and her co-authors are calling on Amazon to stop using plastic packaging in the US, citing phaseouts in some of the company’s biggest overseas markets as evidence that such a transition is possible. Amazon has done “some pretty impressive things in Europe and India, but in the US they are not making the same sort of commitments,” Miller added. “The company has made great progress, but it’s just not enough.”

To calculate Amazon’s US plastics footprint, Oceana used market research on the amount of plastic consumed in 2022 by the American e-commerce industry—more than 800 million pounds — and multiplied that by Amazon’s share of the market, 30.5 percent. Oceana then made some downward revisions to account for Amazon’s publicly disclosed efforts to reduce plastic packaging. For instance, in 2022, Amazon said it replaced  99 percent  of its mixed-material mailers with paper ones and delivered 12 percent of its US shipments in 2022 without adding any of its own packaging.

The resulting estimate, 208 million pounds, is about 11 times the weight of Seattle’s most iconic landmark, the Space Needle.

This is worrisome because the type of plastic typically used in Amazon packaging—known as “film”—is almost never recycled. Most of it is sent to  landfills or incinerators , or is discarded into the environment. According to one  2020 study , plastic film is among the most common forms of marine plastic litter near ocean shores, where it kills more large marine animals than any other type of plastic. Oceana estimates that 22 million pounds of Amazon’s global plastic packaging waste generated in 2022 will end up in aquatic environments.

Plastic production causes additional concerns. The extraction of fossil fuels used to make plastic, plus the conversion of those fossil fuels into plastic products, releases carbon and  air, water, and soil pollution  that  disproportionately affects low-income communities  and communities of color.

Miller said she’d like Amazon to reduce plastics “because of a moral responsibility … to reduce their impact on the environment.” But the company has been slow to respond to moral appeals from customers and shareholders, including  three   shareholder   resolutions  since 2021 invoking plastics’ damages to marine ecosystems and human health. The resolutions, which each received  more than 30 percent  of shareholder votes, asked Amazon to cut plastics use globally by one-third by 2030. When announcing that it had cut plastics use globally by 11.6 percent, Amazon did not make a quantitative or time-bound commitment to further reductions.

Instead, Amazon seems to have taken its biggest steps to reduce plastic packaging in response to stringent plastic regulations, or the threat of them. “Amazon is a clever company,” Miller said. “They see things in the pipeline and they want to move early.”

In 2019, for example, Amazon India  pledged to phase out plastic packaging  after Prime Minister Narendra Modi called on constituents to “ make India free of single-use plastic ,” hinting that he would announce major restrictions on the material later that year. Within months, Amazon India said it had  eliminated plastic packaging  from the country’s fulfillment centers, replacing it largely with paper.

In the European Union, a  directive on single-use plastics  has made it unlawful since 2021 to sell several types of single-use plastic, including bags, and after a long drafting process, the bloc last month agreed to “ historic ” targets to reduce packaging waste by 15 percent by 2040. Amazon said in 2022 that it had  eliminated single-use plastic delivery bags  at its fulfillment centers across the continent.

Despite  efforts from progressive lawmakers , the US still lacks a federal plan to phase down plastic packaging, which could help explain why Amazon hasn’t acted more aggressively on the issue stateside. A spokesperson for the company told Grist last month that Amazon has started a “multiyear effort” to transition US fulfillment centers from plastic to paper packaging, but the company has not announced a timeline for that transition.

Then again, Amazon’s American presence is also much larger than its operations overseas; the fact that US orders make up nearly 70 percent of Amazon’s total sales may make it more complicated to change packaging materials here. 

“It would be a bigger deal for them to eliminate plastics in the United States,” said Jenn Engstrom, director of the California chapter of the nonprofit US Public Interest Research Group, who was not involved in the Oceana report. “But they’re also one of the most innovative and biggest companies in the world; just because it’s hard to do doesn’t mean they shouldn’t do it.” 

Amazon, the largest e-commerce company in the world, sold more than  half a trillion dollars ’ worth of goods last year. Its main American competitor, Walmart, said last month that it had  eliminated single-use plastic  from its mailing envelopes globally. In China, the retailer JD.com is replacing disposable packaging altogether with  reusable alternatives . 

Engstrom pointed to some some state-level policies that could affect Amazon’s plastics use—most notably in California, where a law enacted in 2022  requires that companies reduce their overall packaging distributed in the state by 25 percent by 2032. Washington state tried to pass a similar law last year, but the proposal  died in committee . Five other states have passed less specific bills on “ extended producer responsibility ,” or EPR, that attempt to make plastic producers financially responsible for the waste they generate—often by having them fund improvements in recycling infrastructure.

Although Amazon is funding several  efforts  to  improve   plastics recycling , Oceana says that this is “not the solution the company should be relying on.” Plastic film cannot reliably be recycled due to technical and economic constraints; virtually no curbside recycling program accepts it. In a best-case scenario, plastic film can be downcycled into plastic decking material or benches, but  recent investigations  suggest that store drop-off programs meant to facilitate this process often end up dumping Amazon packaging in landfills or burning it in incinerators.

When American consumers mistakenly put Amazon’s plastic packages in their curbside recycling bins— as many do —a  2022 Bloomberg investigation  found that they may end up at illegal dump sites and industrial furnaces in Muzaffarnagar, India, with potentially dire consequences for nearby residents’ health.

Pat Lindner, Amazon’s vice president of mechatronics and sustainable packaging, called Oceana’s study a “misleading report with exaggerated and inaccurate information,” and told Grist that Amazon is committed to reducing its plastic footprint at US fulfillment centers. A spokesperson said  the company is proud of reducing its plastic footprint in Europe and India and that it would continue to share updates on its progress in the US. The spokesperson also said Amazon is committed to good-faith engagement with shareholders on plastic-related resolutions. 

Oceana said the company declined the nonprofit’s requests for country-level data on its plastics use. The company also declined to share data on plastic packaging used in third-party shipments; Amazon’s disclosures for plastic packaging used in 2021 and 2022 only account for packages shipped from Amazon fulfillment centers. 

“We are hoping that Amazon will provide more detailed data…and illuminate some of these questions,” Miller said.

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Recent Advancements in Plastic Packaging Recycling: A Mini-Review

Valentina beghetto.

1 Department of Molecular Sciences and Nanosystems, University Ca’Foscari of Venice, Via Torino 155, 30172 Mestre, Italy; [email protected] (R.S.); [email protected] (C.B.); ti.evinu.duts@900078 (M.A.-A.); [email protected] (M.F.)

2 Crossing S.r.l., Viale della Repubblica 193/b, 31100 Treviso, Italy

Roberto Sole

Chiara buranello, marco al-abkal, manuela facchin, associated data.

Not applicable.

Today, the scientific community is facing crucial challenges in delivering a healthier world for future generations. Among these, the quest for circular and sustainable approaches for plastic recycling is one of the most demanding for several reasons. Indeed, the massive use of plastic materials over the last century has generated large amounts of long-lasting waste, which, for much time, has not been object of adequate recovery and disposal politics. Most of this waste is generated by packaging materials. Nevertheless, in the last decade, a new trend imposed by environmental concerns brought this topic under the magnifying glass, as testified by the increasing number of related publications. Several methods have been proposed for the recycling of polymeric plastic materials based on chemical or mechanical methods. A panorama of the most promising studies related to the recycling of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polystyrene (PS) is given within this review.

1. Introduction

In recent years, the health of our planet has become a problem of crucial importance, with plastic recovery and disposal being of primary relevance [ 1 ].

Since the introduction of Bakelite in 1907 by Leo H. Baekeland, the first fully synthetic polymer, the plastic industry has evolved to revolutionize the way we live [ 2 , 3 , 4 , 5 ].

Polymers and plastic products own their well-known ubiquity and massive use to their excellent chemical–physical properties, which guarantee light weight, low price, and endurance [ 6 ]. Thanks to their great versatility, plastics are among the most used materials and find applications in many industrial sectors such as packaging, automotive vehicles, construction, and electronic devices [ 1 , 7 , 8 ]. Worldwide, over 360 Mt of fossil-based polymers are produced yearly, with an annual growth rate of 8.4%, two times higher than world global gross growth rate of production over the same period [ 5 ] ( Figure 1 a). The European plastic converter demand in 2018 reached 51.2 Mt, mainly to produce polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS) ( Figure 1 b). These are mainly employed for packaging (39.9%), construction (19.8%), automotive vehicles (9.9%), and electronic devices (6.2%) [ 9 ] ( Figure 1 c).

( a ) World polymer production in metric tons; ( b ) distribution of main polymers produced; ( c ) 2018 European plastic converter demand and use.

A gradual switch to biobased plastics has been witnessed by the increasing use at an industrial level of alternative raw materials [ 10 , 11 ] such as polylactic acid (PLA) [ 12 ], polybutyl succinate (PBS) [ 13 , 14 ], polyhydroxyalkanoate (PHA) [ 15 , 16 , 17 ], and polyethylene furanoate (PEF) [ 18 , 19 , 20 ], together with different composite materials produced from starch [ 21 , 22 , 23 , 24 ], CMC [ 25 , 26 , 27 , 28 , 29 , 30 ], wood [ 31 , 32 ], lignin [ 33 , 34 ], and many different agro-industrial wastes [ 35 , 36 , 37 ].

Nevertheless, 99% of plastics produced today are fossil-based polymers, and they will continue to play an important role in many manufacturing compartments for a long time. In fact, according to the 2020 European Bioplastics report, the EU total production capacity of biopolymers is expected to reach 2.45 Mt by 2024 ( Figure 2 ), which is far lower than the plastic market needs [ 38 ].

Projection of world global production capacity of bioplastics by 2024.

The large gap between market demand and biobased plastics available today clearly shows the complexity of the problem and that all alternatives to approach the problem of plastic use and recycling must be pursued to reduce the environmental impact of polymers and plastic waste. In a recent article by Mendes and coworkers, the benefits of the use of bioplastics for the packaging industry were analyzed with the intent of delivering a guide for the design of more sustainable packaging to food packaging designers and producers [ 39 ]. The authors concluded that, from a climate point, the use of biobased plastics contributes to the generation of more sustainable food packaging compared to fossil-based ones; however, on the other hand, the relevance of some environmental problems originating from biobased plastics, such as eutrophication, use of water and pesticides, and effects on biodiversity, significantly reduces their environmental benefits.

Additionally, fossil-based plastics are generally scantly biodegradable and accumulate in the environment, posing serious waste management problems. Over the last 65 years, approximately 8300 Mt of fossil-based polymers were produced, 4900 Mt of which were landfilled, incinerated, or dispersed in the environment [ 5 , 40 ]. Thus, oceans, animals, and humans are inevitably exposed to different sources of contamination from plastic waste [ 41 , 42 , 43 , 44 , 45 , 46 ]. Climate changes, environmental modifications, and health pandemics are becoming more and more frequent, showing that humanity will have to rethink its unsustainable growth [ 47 , 48 ] by adopting a circular economy approach to resource consumption through eco-design, recovery, and recycling of polymeric materials with an integrated approach [ 49 , 50 , 51 , 52 , 53 ]. Circular economy is pushing toward a radical change in production and waste management to reduce water, waste, and energy consumption and to achieve zero-waste manufacturing cycles [ 10 , 54 , 55 , 56 , 57 ]. In this frame, European countries have developed different waste management systems and recycling techniques [ 58 , 59 , 60 , 61 , 62 , 63 , 64 ]. Nevertheless, a great part of post-consumer managed plastic is currently sent to incineration or landfill, while mismanaged waste is either discarded into the environment or is inadequately disposed of, potentially ending up in the ocean [ 46 ]. From 2006 to 2018, the amount of recycled post-consumer plastic waste doubled, reaching 32.5% (29.1 Mt), while 42.6% was used for energy production and 24.9% was landfilled [ 9 ] ( Figure 3 ).

Reuse of recovered post-consumer plastic waste.

In 2018, 5 Mt of plastic waste was recycled in Europe, 80% of which re-entered the EU as secondary materials, while the remaining 20% was exported outside the EU. The main industrial uses of recycled plastics in the EU are building and construction (46%), packaging (24%), agricultural applications (13%), and others (17%) [ 9 ].

Plastics may be subdivided into three categories: plastics in use, managed post-consumer plastic waste, and mismanaged plastic waste [ 65 , 66 ]. Managed plastic waste is generally disposed of by recycling, although a substantial gap exists between the quantity of plastic produced each year and the quantity of plastic thrown away since, depending on the type of product, there will be different storage and use times. Packaging products end their lifecycle generally in less than 1 year, while materials used for the construction and transport industry may last much longer. This means that the amount of waste produced each year is less than the amount of plastic in use. In 2015, 407 Mt of primary plastic entered the use phase, while only 307 Mt exited the use phase, with a consequent increase of 100 Mt of plastic in use [ 5 ].

According to the literature, it was estimated that, in 2010, between 4.8 and 12.7 Mt of plastics were leached into the ocean, predicting that, with inadequate waste management strategies, these numbers will increase by an order of magnitude by 2025 [ 46 , 67 ]. On this note, in January 2018, the European Commission issued the “European strategy for plastics in a circular economy” [ 68 ], including the ambitious target to make all plastics in EU recyclable by 2030. Soon after, in March 2018, China banned imports of plastic, generating a decrease in plastic waste export from EU of 39%, thereby overloading the EU waste management system and incinerators [ 65 , 69 ].

To reduce the amount of plastic waste disposed in landfills or incinerated, there are two main strategies: the use of biodegradable biobased plastics (as mentioned above) [ 38 , 70 ] and recycling [ 71 , 72 , 73 , 74 ]. It should be reaffirmed that not all biobased polymers are biodegradable, while some fossil-based ones are, as clearly reported in Figure 4 .

Examples of biobased and fossil-based polymers subdivided into biodegradable and not biodegradable.

Moreover, the recovery and recycling of biobased polymers is a relatively new issue and is still the object of studies compared to fossil-based polymers [ 39 , 75 ]; thus, different strategies will need to be put in place to implement the environmental sustainability of polymer manufacturing and recycling. According to the recent Circular Economy Package EU legislation and a paper by Briassoulis and coworkers, mechanical recycling is the best alternative for the valorization of both post-consumer fossil-based and biobased polymer waste, followed by chemical recycling [ 75 , 76 ].

The topic of sustainable manufacturing of plastics and packaging is so important that, from a research on Google Scholar using as key words “sustainable plastics”, “recycled plastic”, and “plastic recycling techniques”, a total of almost 95,000 papers were published between 2019 and 2021. This mini-review intends to give an outlook on different mechanical and chemical recycling techniques, giving a general panorama of the state of the art and recent innovative solutions by focusing mainly on papers published in the last 12 months relevant to plastic packaging. The scope of the work is to give a general overview of most recent technologies for the recycling of post-consumer packaging waste (PP, LDPE, HDPE, PET, and PS) to be used as secondary materials for the manufacturing of different materials. Since it is possible that the EU will implement plastic recycling up to 100% by 2050, avoiding the use of virgin naphtha for its production, the use of plastic waste as a source of energy seems bound to assume a minor importance in the future, while recycling of polymers to produce high-value products will be of strategic importance. For this reason, techniques to produce energy from plastic waste will not be discussed in this mini-review. The authors believe that a good understanding of the possible alternatives to plastic recycling and valorization, together with the difficulties encountered in sorting and reprocessing of post-consumer plastic waste, should help the industry, as well as end users, to adopt more responsible behavior and, consequently, promote the introduction of environmentally sustainable solutions.

2. Overview of Plastic Recycling Techniques

The word recycling refers to a set of modifications and transformations (mechanical treatment, chemical treatment, or heating) required to recover feedstock from a previously processed polymer which can be reused by the industry [ 73 , 77 , 78 ]. Plastic recycling methods available today are classified in primary to quaternary processes [ 79 , 80 ] ( Scheme 1 ).

Specifically, primary processes allow recovering and recycling pre-consumer or pure polymers which can be reused for the same scope. Secondary processes start from recovered post-consumer polymeric waste, which is sorted, trimmed, and re-extruded, giving a product with reduced physical–mechanical characteristics compared to the starting polymer, which in most cases cannot be reused for the same scope. Primary and secondary recycling represents physical processes that can be repeated several times. Tertiary processes adopt chemical recycling starting from polymers which may no longer undergo mechanical recycling, while quaternary ones are used for energy production. Polymers and plastics sent to landfill (end-of-life plastics) lose their value and become waste.

Different techniques adopted for plastic waste separation, processing, and possible reuse as secondary materials depend on the type of waste recovered. A first important distinction should be made between thermoplastic and thermoset polymers. Thermoplastics are usually processed by extrusion, as these polymers melt when heated and harden when cooled. A great advantage of thermoplastics is that the extrusion process can be repeated many times. The most used thermoplastics are PP, PET, LDPE, HDPE, PVC, and PS. Adversely, thermosets may not be reprocessed by extrusion since, when heated, an irreversible chemical reaction takes place. Main thermoset plastics are polyurethanes (PUR), resins (epoxy, phenol-formaldehyde, and polyester), and vulcanized rubber, widely used by the automotive and electronic industry. The most abundant polymers in post-consumer waste are polyolefins (PP, LDPE, HDPE, PET, and PS) used for packaging [ 58 , 81 , 82 ], with a consumption of over 23 Mt only in the EU in 2020.

3. Primary and Secondary Recycling

Mechanical recycling is the main and most widely used technology for plastic recycling, consisting of several steps, including collection, screening, automatic or manual sorting, washing, shredding, extrusion, and granulation [ 83 , 84 , 85 , 86 ] ( Scheme 2 ). Mechanical recycling is classified as primary or secondary according to the type of starting material being processed. Primary recycling gives the highest-quality recycled polymers and starts from closed-loop recycled products such as PET bottles or byproducts collected by manufacturing industries as pre-consumer well-separated material.

Secondary processes instead recover post-consumer plastics and, therefore, generate lower-quality polymers. It must nevertheless be considered that, from an economic standpoint, these processes have a reduced complexity and overall limited costs, generating significant income and reduced CO 2 production. According to the Ellen MacArthur foundation report, plastic production and incineration of plastic waste are estimated to produce over 400 Mt of CO 2 yearly [ 87 , 88 ]. Thus, recycled plastics can reduce fossil-fuel consumption and CO 2 emissions. According to estimates by Rahimi and coworkers [ 89 ], the adoption of plastic waste recycling worldwide would allow saving about 3.5 million barrels of oil each year.

Mechanical recycling generally includes four main steps: (i) screening and sorting; (ii) shredding; (iii) washing and drying; (iv) melting and reprocessing ( Scheme 2 ).

Screening and sorting of plastic waste is a fundamental step for the recyclability of the different plastics and the quality of the final polymer. This step is challenging, considering that the separation of mixed plastic waste often involves the combined use of different technologies [ 90 , 91 ].

To achieve an adequate separation of a specific polymer within a flow stream containing many different components (plastics, as well as metals, paper, organic residues, and dirt), characteristics of the final product must be accurately considered such as purity and destination. This will allow defining the best separation strategy to achieve high selection. Important properties commonly employed for plastic separation are magnetic or electric properties, particle size, density, and color. Relying on these properties, many different separation techniques have been developed such as dry or wet gravity separation, electronic or magnetic density separation, flotation, and sensor-based sorting together with auxiliary segregation techniques such as magnetic or eddy-current separation. These segregation methods are briefly described, mainly focusing on recently implemented technologies for PE, PP, PET, and PS recovery.

Gravity separation is a consolidated methodology that may be carried out in a dry environment (dry process) or in the presence of water (wet process) [ 63 , 92 ] ( Figure 5 a). Dry segregation techniques employ air classifiers or ballistic separators in which air is used as the medium to separate lighter materials from heavier ones. They can be positioned at the beginning of the process or at the end, to segregate end-of-life plastics from main plastic streams ( Figure 5 b). Wet gravity separation includes sink and float, jigging, and hydrocyclone techniques.

( a ) Different methodologies of gravity separation; ( b ) dry segregation; ( c ) sink and float separation; ( d ) hydrocycloning; ( e ) eddy current separator.

With sink and float separation, polymers are separated into two different streams depending on whether they have a higher or lower density than water. Materials such as PET, PVC, and PS will sink, while others such as PE, PP, and expanded polystyrene will float ( Figure 5 c). This type of separation guarantees an effective first separation, but it is not adequate to produce high-quality secondary materials and needs to be combined with other separation techniques [ 93 , 94 , 95 ].

Zhang and coworkers developed a pretreatment of PET via preliminary NaOH and ethanol hydrolysis to promote plastic flotation. Optimal conditions allowed the quantitative recovery of highly pure PET fractions [ 96 ].

Heidarpour and coworkers reported the influence of microwave irradiation in the presence of chemical additives such as PEG-400, methylcellulose, or tannic acid on the float–sink behavior of polyoxymethylene, polycarbonate, and polyvinyl alcohol. According to this study, microwave irradiation reduced the contact angle values of tested plastic surface in the presence of chemical additives (depressant) by implementing their sink–float separation capacity, thereby increasing their hydrophilicity [ 97 ]. The authors mention the possibility of using this technology for whichever plastic material.

Jigging is one of the oldest gravity separation techniques and is similar to dry gravity methods where, in most cases, water is used instead of air [ 90 , 94 ]. A water stream is pushed up and down by pistons, and plastics are separated mainly depending on their morphological and physical characteristics.

Hydrocycloning is based on centrifugal and centripetal forces together with the fluid resistance of different materials processed ( Figure 5 d). New trends in hydrocycloning separation focus especially on the recovery of precious metals from electronic device waste [ 98 , 99 ], and it seems to be a very valuable tool for more sustainable separation of plastic waste from metals.

The eddy current separator is made of a high-speed magnetic rotor which generates an electric current, the so-called eddy current, used to remove nonferrous metals (aluminum and copper) from waste plastic, glass, and paper, among others ( Figure 5 e) [ 100 ]. These separators are generally located at the beginning of the recycling process.

With a separator and drum screen, plastics are fed into a large rotating drum where materials are separated by size, thanks to holes in the drum, so that only smaller particles pass through and are separated from larger ones.

Different gravity segregation methods were analyzed by Nie and coworkers for the sustainable recovery and recycling of high-value metals from waste printed circuit board (WPCBs) [ 101 ]. This study analyzed the dynamics and statics of gravity concentration methods. The settling velocity of three kind of particles was studied, demonstrating that the stratification by density is spontaneous and can achieve the lowest potential energy. The concentration of differently sized metal particles could be effectively enriched, and the metal purity increased from 56.5% to 68.2% for decreasing particle size, albeit with a modest decrease in yield (from 86.41% to 83.04%). No recent papers were found for the use of innovative solutions for the recovery of PE, PP, PET, or PS by jigging, hydrocycloning, eddy current separation, and drum and different gravity segregation techniques, but they were reported to give a general overview of different separation technologies available.

Optical sensors are used for the characterization of plastic stream in a continuous manner where air jets allow for separation. Optical sensors may be subdivided in molecular spectroscopies and atomic spectroscopies [ 102 ], the prevalently used Raman spectroscopy (RS) [ 103 ], Fourier-transform infrared spectroscopy (FTIR) [ 96 ], near-infrared spectroscopy (NIRS) [ 104 ], and terahertz spectroscopy (THz) [ 105 ], and elemental spectroscopies such as laser-induced breakdown spectroscopy (LIBS) [ 106 ] and X-ray fluorescence spectroscopy (XRFS) [ 102 ].

Bobulski and coworkers implemented new portable devices for computer image recognition in combination with artificial intelligence for waste recognition and easy municipal waste separation. The devices were used both at home and in waste sorting plants, and they could be a very useful tool for an efficient and economically sustainable separation of plastic waste stream [ 107 ].

Most companies use a combination of different separation techniques to obtain sufficiently pure polymers from post-consumer plastic waste. The purity of the finished product depends on an adequate compromise between costs and benefits, and this leads to purities ≤95% which require further separation and purification steps. Sorting technologies reported above are generally inadequate for the separation of complex materials such as multilayered packaging or fiber-reinforced composites; therefore, these materials are generally incinerated for energy recovery or landfilled as end-of-life plastics.

Innovative recycling methods such as selective polymer dissolution were demonstrated to be efficient in extracting different polymers and fibers from multilayered films and composite materials [ 108 ]. In fact, Knappich and coworkers reported the efficient recovery and recyclability of epoxy and polyurethane resins from carbon fiber-reinforced plastics with different proprietary CreaSolv ® formulations at a laboratory scale.

Multi-material plastic waste separation technologies are also being developed to enable a proper sorting of composites, which will generate new value streams to recover and recycle plastics which are today incinerated or landfilled [ 109 ]. Many approaches have been tested, for example, for the separation of polyester from cotton fibers to recycle textile waste. Solvent-based technologies are an interesting solution, with the possibility of selecting specific solvents which may solubilize either cotton or polyesters [ 110 ]. A crucial aspect for industrial success and applicability is the nature of the solvent in terms of volatility, flammability, toxicity, and recyclability [ 111 ].

Once the mechanical separation is complete, the materials are shredded by passing them through a system of rotating blades. The obtained flakes are then sorted by size with a grid, washed and dried, made ready for reprocessing by extrusion or agglomeration, and sold.

Agglomeration is generally used to reprocess plastic films which are cut in small pieces, heated by friction and water-cooled. The agglomerates are usually combined into plastic flakes and pelletized by extrusion. Agglomeration is highly energy-consuming and, therefore, less widespread [ 90 ].

Extrusion remains the most widely used method for processing both virgin and recycled plastic. Plastic flakes are fed into the extruder and pushed by a screw into a heated cylinder, thus melting the plastic. At the end of the extruder, a pelletizer cools and cuts the final polymer into pellets.

Both shredding and extrusion may lead to partial degradation of the polymer due to chain scission and thermo-oxidative reactions, reducing the polymer chain length and, consequently, its mechanical properties [ 112 , 113 ]. Moreover, impurities deriving from other packaging components further contribute to the diminished physical–mechanical characteristics of reprocessed plastics [ 104 ].

A detailed study was published by Eriksen and coworkers on the thermal degradation, processability, and mechanical properties of re-extruded PET, PE, and PP from post-consumer waste. PET is well suited for closed-loop recycling to meet bottle and food-grade PET quality, although moisture control is a key requirement when reprocessing PET into products. For this polymer, degradation, which generally occurs during recycling by extrusion, may be avoided by careful decontamination. The quality of reprocessed PE samples from non-food bottles strongly depends on the presence of impurities from other polymers and from lids and labels. PE reprocessing by extrusion suggested that closed-loop recycling may be achieved with selected PE bags with low levels of polymer cross-contamination. Adversely, PP reprocessed by extrusion showed low mechanical properties with large variations in impact strength, reducing possible applications of reprocessed PP. Thus, the heterogeneity of PP waste, even if food packaging is managed separately, as well as polymer degradation during recycling, represents crucial limitations for PP waste recycling [ 114 ].

A possible remedy to downgrading due to extrusion was reported for the first time by Wang and coworkers. The authors reported a process to modify polyolefins from post-consumer plastic waste via a one-step radical grafting and cross-linking process, producing covalent adaptable networks or CANs [ 112 ]. This procedure relies on the functionalization of polyolefins with polar reagents, which modify the properties of the starting material, thus imparting new characteristics such as wettability, printability, and compatibility with other polymers. Upcycling of LDPE from plastic bags was achieved by free-radical reaction in a twin-screw extruder in the presence of maleic anhydride and butanediol. PE-CANs showed higher solvent resistance, tensile strength, and modulus compared to virgin PE due to the presence of cross-linking bonds generated during the extrusion process. Upcycling of post-consumer plastic waste by reactive extrusion is an interesting area of research which will surely receive much attention in the future; however, characteristics of CAN polymers must be acquired to define new possible manufacturing applications [ 115 ].

4. Chemical Depolymerization

In addition to mechanical methods, recycling can be performed via chemical depolymerization [ 111 , 116 ].

Chemical recycling has great potential in the circular economy of plastics; it can close the loop by producing starting monomers from the polymers that may be reprocessed to produce high-value-added chemicals [ 70 ]. It is estimated that, by 2050, almost 60% of plastic production can be based on recycled products [ 117 ]. Millions of euros are being invested to enhance chemical recycling and other cutting-edge technological solutions with the aim of producing 1.2 Mt of recycled plastic in EU by 2025 and 3.4 Mt by 2030 [ 9 ].

Chemical recycling methods are classified according to reaction conditions into solvolysis (hydrolysis, methanolysis, and glycolysis), catalytic depolymerization, and enzymatic depolymerization [ 83 , 84 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 ]. Only main innovative solutions devised in the last year for plastic packaging chemical recycling are analyzed below i.e., PE, PP, PET, and PS.

4.1. Solvolysis

Solvolysis involves the breaking of the hydrolyzable bonds of a polymer in the presence of an alcohol or water. It is rather frequent that, to improve reaction conditions, product selectivity, and yield, catalysts are used to promote solvolysis reactions [ 83 , 84 , 119 , 128 ].

4.1.1. Hydrolysis

Hydrolysis reactions perform better from an environmental point of view but require higher energy consumption compared to other solvolysis methods [ 129 ]. They may be carried out in neutral, acidic, or alkaline conditions.

Neutral hydrolysis of PET has long been known and is generally processed in the molten phase, at temperatures above 245 °C with a water/PET ( w / w ) ratio above 5.1/1. A further improvement in the rate of the reaction may be achieved via the addition of catalytic amounts of alkali metal acetates, organophosphorus compounds, or zeolites [ 128 ]. Recently, Colnik and coworkers reported hydrolytic recycling of colorless and colored PET bottles in sub- and supercritical water with temperatures between 250 and 400 °C, in 1 to 30 min. Highest yields in terephthalic acid (TPA) were achieved at 300 °C in 30 min with purities near to 100% [ 130 ] ( Scheme 3 ).

Interestingly, according to the work by Stanica-Ezeanu and coworkers, sea salt is an efficient neutral catalyst promoting PET degradation; by means of a mathematical model, it was estimated that, in tropical regions, only 72 years are necessary for spontaneous complete degradation of PET to occur [ 131 ].

Acid hydrolysis of PET proceeds by polymer dissolution in concentrated acids (H 2 SO 4 , H 3 PO 4 , and HNO 3 ) and heating, leading to chain fragmentation at high temperature.

These processes have not been, to the best of our knowledge, the object of recent studies, probably due to their low environmental sustainability; therefore, they are not further discussed in this review.

Alkali-promoted glycolysis of PET has been widely reported using both inorganic and organic bases [ 132 ]. Due to the high quantities of alkali required and consequent environmental impact of the process, in this case, no innovative solutions were found in recent publications.

4.1.2. Methanolysis

Methanol is widely used and is effective for the solvolysis of various polymers such as PET, polyamides, and polycarbonates. The majority of post-consumer recovered PET is currently reprocessed by mechanical recycling; however, this process leads to molar mass reduction and a consequent reduction in the physical–mechanical properties of the polymer, which is generally used to produce carpets (72%) [ 70 ], along with a small percentage of PET for bottle production [ 129 ]. Moreover, the commercial appeal of mechanical recycled PET depends on the price of oil; thus, when oil is available at prices below $65 per barrel, mechanically recycled PET is no longer competitive [ 70 ]. Chemical depolymerization to produce high-quality monomers and oligomers may be a solution to this problem.

The primary scope of PET chemical recycling is to regenerate TPA, dimethyl terephthalate (DMT), bis(2-hydroxyethyl) terephthalate (BHET), and ethylene glycol (EG) [ 133 ] or other chemical substances [ 134 , 135 ] ( Scheme 3 ).

Methanolysis of PET is generally a degradation process performed at high temperatures (180–280 °C) and pressures (2–4 MPa), and the major products are DMT and EG [ 70 , 129 ], with high capital and operating costs. Recently, Pham and coworkers [ 124 ] developed a low-energy catalyzed methanolysis to convert PET into DMT at room temperature in the presence of K 2 CO 3 as a catalyst. Despite the overall reaction time of 24 h, PET resins were completely decomposed into monomers with high selectivity in DMT with 93.1% yield at 25 °C. 2-Hydroxyethyl methyl terephthalate (HEMT) and monomethyl terephthalate (MMT) were the major byproducts collected after the reaction ( Scheme 4 ).

Myren and coworkers described a new method for methanolysis of post-consumer PET waste in the presence of NaOH carried out in a microwave or electrochemical reactors. Under mild reaction conditions (85 °C, 40 min) overall yields in TPA of 65% were achieved under microwave irradiation [ 136 ].

Barnard and coworkers published a review in 2021 evaluating advantages and disadvantages of chemical recycling of PET based on the energy economy coefficient and environmental energy impact. Different technologies evaluated comprised neutral, acidic, or alkaline hydrolysis, enzymatic hydrolysis, solvolysis, glycolysis, and aminolysis. From the comparison of data collected, alcoholysis was the most energetically expensive process; moreover, the low boiling point of alcohols generally requires high-pressure reactors. On the contrary, methanolysis carried out in the presence of a nanodispersion of ZnO was found to be the least energetically expensive process for PET degradation, giving high-quality DMT [ 129 , 137 ].

Additionally, Zhang and coworkers proposed a novel, simple and economic hydrophilic modification of PET by surface alcoholysis in the presence of ethanol and a sodium hydroxide water solution, which influenced the wettability of PET and promoted sink–float separation from hydrophobic PS, PVC, and PMMA [ 96 ].

Another very interesting example of the methanolysis of PET was achieved in the presence of an organocatalyst prepared from very simple reagents such as tetramethyl ammonium hydroxide and dimethyl carbonate, [NMe 4 ] + [OCO 2 Me] − , achieving good yields of DMT (≤75%) in mild reaction conditions (100 °C and 4 wt.% organocatalyst) [ 138 ]. Nevertheless, long reaction times (16 h), solvents, and product purification were necessary. Alternatively, imidazolium metal-based ionic liquids (ILs) can achieve a comparable or even better performance than [NMe 4 ] + [OCO 2 Me] − [ 139 ]. Main ILs reported in the literature are depicted in Figure 6 .

Main ILs reported in literature.

4.1.3. Glycolysis

Glycolysis was also verified to be a promising alternative with moderate energy and environmental impact [ 129 ]. Glycolysis produces the BHET monomer, which is a good starting material for PET upcycling. As reported by Lalhmangaihzuala and coworkers, glycolysis of post-consumer PET waste may be efficiently promoted by heterogenous catalysts prepared from orange peel ash. Total depolymerization of PET was detected within 90 min, producing BHET in 79% yield. The catalysts were recovered up to five times without significant deactivation. This study opens the way to a highly environmentally sustainable approach to post-consumer plastic waste recycling [ 127 ].

Organocatalyst-assisted glycolysis is considered a new frontier for a green approach to plastic recycling in comparison to conventional organometallic complexes [ 138 , 140 ]. Wang and coworkers [ 141 ] reported a very promising study on the glycolysis of PET using 1,3-dimethylimidazolium-2-carboxylate as an organocatalyst, achieving complete depolymerization in less than 1 h at 180 °C, with up to 60% yield in BHET recovered by precipitation from the reaction mixture upon cooling.

Alternatively, Fuentes and coworkers reported the glycolysis of PET bottles to BHET in the presence of catalytic amounts of different metal oxides (ZnO, CoO) obtained for the recycling of spent alkaline and lithium-ion batteries. Reactions were carried out in EG at approximately 200 °C for 2 h; in the best conditions, yields of the BHET reached 80% [ 126 ].

Functionalization of silica-coated, magnetic Fe 3 O 4 nanoparticles, with an iron-containing ionic liquid, was recently employed for the glycolysis of PET to BHET. The advantage of these catalysts is in their high recyclability and ease of recovery due to their magnetic properties, and no traces of metals were found in the final products [ 142 ].

4.1.4. Aminolysis

While aminolysis presents the best energy and environmental parameters, the use of ammonium-based ionic liquids makes the production process more expensive [ 129 , 143 , 144 ]. The high temperatures involved in aminolysis are compensated for by very low depolymerization times due to increased reaction speed. Adversely, depolymerization by aminolysis of PET produces terephthalamides which have limited industrial applications. Different amines such as monoethanolamine (MEA) have been used for the aminolysis of PET with and without catalysts such as metal salts, quaternary ammonium compounds, and ionic liquids [ 145 ] ( Scheme 5 ).

Catalyst-free, microwave-assisted aminolysis of PET proved to be an efficient method for the recovery of different terephthalamides starting from allylamine, ethanolamine, furfurylamine, or hexylamine with high selectively and yields. Terephthalamides were employed to produce good quality films [ 123 ]. Furthermore, aminolytic upcycling of PET post-consumer waste was achieved in the presence of different amino-alcohols in the presence of various organocatalysts to give diol terephthalamides, which were employed to produce poly(ester-amides) [ 146 ].

4.2. Catalytic Depolymerization

Plastic depolymerization may be carried out in the presence of different catalysts such as strong mineral acids, bases, organocatalysts, enzymes, and metal catalysts in homogeneous or heterogeneous phase [ 147 ].

4.2.1. Enzymatic Catalysis

To date, the enzymatic activity of various microbial and fungal species has been tested for the degradation of various polymers [ 148 , 149 ]. As with chemical degradation, the major difficulty in the enzyme degradation of polymers such as PE and PP derives from their high hydrophobicity, stability, and inertness, and their reactivity may be implemented by UV or thermal oxidation pretreatments [ 150 ]. While PE and PP enzymatic degradation is still a very challenging topic, numerous hydrolytic enzymes have been identified and are efficient for PET degradation [ 151 ]. PET hydrolases represent one of the most recent breakthroughs in the depolymerization of post-consumer PET, allowing the recovery of terephthalic acid and ethylene glycol at industrial relevant scale [ 120 ]. Interestingly, Sadler and coworkers developed an innovative enzyme-catalyzed post-consumer PET hydrolysis with engineered Escherichia coli to produce vanillin [ 134 ].

These new technologies once more highlight the importance of the development of specifically devised new microorganisms and enzymes for plastic depolymerization. In this connection, Santacruz Juarez and coworkers reported the use of molecular docking simulation to predict affinity, strength, and binding energy between two molecules to analyze the activity of laccase (Lac), manganese peroxidase (MnP), lignin peroxidase (LiP), and unspecific peroxygenase (UnP), thereby helping in the development of new enzymes [ 152 ]. Data achieved showed that synergic enzymatic combination, as it normally happens in nature, boosts the catalytic efficiency by promoting sequential degradation processes. The use of microorganisms and enzymes has been widely studied with the intent to find an environmentally sustainable solution to microplastic and nanoplastic contamination. Taghavi reviewed the state of the art of plastic packaging biodegradation by living microorganisms reporting mechanisms of action, advantages, limitations, and technology readiness levels (TRL). The focus of this very important research area is a reduction in plastic pollution in the environment more so than its recovery and reuse; thus, it is not further analyzed in this paper [ 148 ].

4.2.2. Hydrogenolysis

Hydrogenolysis is widely employed for the depolymerization of PET in the presence of hydrogen and homogeneous Milstein-type Ru–PNN complexes which are highly reactive toward the C=O double bonds of PET to give 4-benzenedimethanol (BDM) in 99% yield at 160 °C in 48 h ( Table 1 , entry 1), while they are ineffective in the presence of PP and PE [ 147 , 153 , 154 , 155 ]. More complex phosphine ligands have also been tested, but the economic viability on an industrial scale seems to be rather limited [ 147 ] ( Table 1 , entries 2–3).

Phosphine ligands of Milstein-type Ru–PNN complexes.

1 Selectivity to BDM. 2 Selectivity to BTX.

Two very important studies have been published on the efficient conversion of post-consumer PET to benzene, toluene, and xylenes by reportedly “unlocking hidden hydrogen in the ethylene glycol part” with Ru/Nb 2 O 5 catalyst [ 156 , 157 ]. The hydrogen is formed in situ during the reaction from ethylene glycol, and it appears that, in the presence of Ru/Nb 2 O 5 , two different pathways (decarboxylation and hydrogenolysis) compete to determine the selectivity toward alkyl-aromatic compounds ( Table 1 , entries 4–5) [ 156 ].

Solventless hydrolysis of PET bottles to TPA and ethylene has been selectively achieved by a carbon-supported single-site molybdenum-dioxo catalyst under 260 °C and 1 atmosphere of H 2 with 87% yield. The catalyst exhibits high stability and can be recycled many times without loss of activity [ 158 ].

Hydrogenolysis of PET to liquid alkanes has been carried out under mild reaction conditions using ruthenium nanoparticles supported on carbon (Ru/C). Under optimal reaction conditions (200 °C, 20 bar H 2 , 16 h), PE was converted into liquid n -alkanes with 45% yield [ 159 ]. Another SnPt/γ-Al 2 O 3 and Re 2 O 7 /γ-Al 2 O 3 heterogeneous catalyst was used to produce linear alkanes from HDPE. This type of catalyst promotes a tandem reaction via which poorly reactive aliphatic substrates are first activated through dehydrogenation and then functionalized or cleaved by a highly active olefin catalyst [ 160 ].

These technologies are particularly attractive from an industrial point of view as heterogeneous catalysts are generally easier to use and economically more sustainable than homogeneous ones.

4.2.3. Hydrosilylation

Hydrosilylation carried out in the presence of different silanes (tetramethyldisiloxane and polymethylhydrosiloxane) and borane or Ir catalysts has also been tested in the past for the depolymerization of PET, PS, and PVC [ 161 ]. Probably because of the high cost of reagents and Ir catalysts, combined with low yields in monomers recovered, no similar studies were published in the last 12 months. An interesting alternative was proposed by Fernandes and coworkers in 2020 for the depolymerization of PET by silanes and an air-stable, cost-effective dioxomolybdenum complex, MoO 2 Cl 2 (H 2 O) 2 . Although reaction conditions are rather harsh (160 °C, 4 days), very good yields in p -xylene were achieved for the reductive depolymerization of PET (65% yield) in the presence of 5 wt.% MoO 2 Cl 2 (H 2 O) 2 and six equivalents of phenylsilane. In another study, Fernandes described the first example of reductive hydrosilylation of PET and other plastic waste using an economically and environmentally sustainable Zn catalyst, Zn(OAc) 2 ·2H 2 O, to produce high-value-added compounds such as 1,2-propanediol, 1,6-hexanediol, tetrahydrofuran, and p -xylene. In the same reaction conditions, in the presence of Mo oxides, yields in p -xylene were equivalent while higher yields in EG were obtained (43%) [ 162 ]. Much work surely needs to be done to implement these technologies to industrial maturity, but the use of highly available, environmentally friendly catalysts is a great advantage and should be further pursued.

5. Thermal Recycling

Thermal recycling mainly comprises pyrolysis, hydrocracking, and gasification ( Scheme 6 ) [ 163 ]. Since there are no recent advancements for gasification, only pyrolysis and hydrocracking are reported. An outline of the main innovative solutions recently published is reported below.

5.1. Pyrolysis

Pyrolysis, or thermal cracking, is a process that occurs at high temperatures (500 °C) and in the absence of oxygen. Different kinds of catalysts can be used to improve the efficiency of the pyrolysis process since they target a specific reaction and reduce the process temperature and time [ 164 ]. Unlike other thermochemical conversion methods, pyrolysis leads to liquid or wax mixtures rich in hydrocarbons, an ideal raw material for a refinery [ 165 ]. Thermal pyrolysis is typically used for the recycling of those polymers for which depolymerization is harsh and that are not currently mechanically recyclable (PE/PP/PS mixtures, multilayer packaging, and reinforced fibers). Thanks to the high temperatures, it guarantees molecular bond breaking in the polymer chains to give, depending on the nature of the polymer, depolymerization or random fragmentation [ 122 , 166 ]. Alternatively, catalytic pyrolysis can be performed on the same polymers at lower temperatures by carbocation formation and subsequent isomerization [ 161 ]. Both thermal and catalytic pyrolysis approaches are not selective, but advantages rely on high conversions, thermal stability of the products and, in some cases, high-value enriched oil production. Pyrolysis, therefore, is an interesting recycling approach for a safe circular economy [ 161 , 166 ].

Pyrolysis must be preceded by pretreatment of the plastic waste, to ensure that it is not contaminated by non-plastic materials such as metal and wood. This step is necessary to ensure the economic feasibility of the plastic-to-fuel (PTF) plant, and it can usually be achieved by sorting, crushing, or sieving depending on the origin of the waste. Since pretreatment techniques are consolidated methodologies, no innovative methods were reported in the last year.

Another important aspect derives from different sources of plastic processed which may be different in shape and size, requiring to be uniformly sized as grains before feeding into the pyrolysis process. This step adds an extra cost to the process.

Depending on the type of reactor, the pre-sizing step can be skipped or modified. For example, rotary kilns can accommodate differently sized and shaped plastics; hence, the pre-sizing step can be avoided. Fluidized bed reactors, instead, need to have uniform thermodynamics in the reactor; therefore, plastic waste should be evenly sized. To cope with this challenge, several feeding devices have been tested [ 166 ].

Currently, the study of catalytic pyrolysis is very active, and a wide range of synthetic catalysts have been employed to enhance the overall pyrolysis process and to improve the quality of produced liquid oil.

Most PE pyrolysis approaches are promoted by heterogeneous acid catalysts (e.g., zeolites, alumina, and silica) and are usually unselective, resulting in a broad distribution of gas (C3 and C4 hydrocarbons), liquid (cycloparaffins, oligomers, and aromatics), and solid products (char, coke). This behavior is due to the radical mechanism of the C–C bond scission, leading to a complex mixture of olefinic and cross-linked compound [ 122 , 166 ].

A very recent novel study on this topic was carried out by Miandad and coworkers, in which the effect on yield and product quality of Saudi natural zeolite was investigated [ 164 ]. Saudi natural zeolite catalyst was improved via novel thermal activation (TA-NZ) at 550 °C and acid activation (AA-NZ) with HNO 3 . Pyrolysis feedstock was composed of single or mixed PS, PE, PP, and PET, in the presence of both modified natural zeolite (NZ) catalysts. The authors reported that PS produced the highest yield in liquid oil, i.e., 70% and 60% using the TA-NZ and AA-NZ catalysts, respectively, compared to PP (40% and 54%) and PE (40% and 42%).

In addition to zeolite, the research on catalytic pyrolysis has focused on other catalytic systems, always considering that the catalytic activity of the catalyst is derived from its Lewis acid sites. Most homogeneous catalysts for polyolefin degradation have been classical Lewis acids such as AlCl 3 . On the basis of these considerations, Su and coworkers [ 167 ] worked on AlCl 3 –NaCl eutectic salt as a catalyst, allowing a reduction in reaction temperature, an increase in reaction rate, a reduction in heavy oil components, and the inhibition of polyolefin formation.

Pyrolysis is most often adopted to convert plastic waste to fuels. An example of differentiation is the production of high-value-added carbon nanotubes (CNTs) [ 168 ] using a metallic Ni catalyst supported on different oxides and generated in situ. Selectivity, yield, and structural properties were tuned according to the degree of metal–support interaction in different catalysts.

5.2. Hydrocracking

Hydrocracking is a catalytic refining process for the selective recovery of useful chemical fractions in the range of heavy diesel to light naphtha. Hydrocracking requires a bifunctional catalyst with an acidic function, enhancing the cracking activity, typically provided by a high-surface-area support, such as a zeolite [ 169 ].

Recent studies have focused on the conversion of both post-consumer and laboratory polymers in mild conditions, using a metal–zeolite catalytic system.

Jumah and coworkers [ 170 ] treated low- and high-density polyethylene (LDPE, HDPE), polypropylene (PP), and polystyrene (PS) to produce liquid petrol gas (C3–C4) and naphtha. They reported the effect of both the catalyst morphology (beta zeolite impregnated with 1% Pt) and the feed stream variation, by reacting different polymers individually and post-consumer polymer mixtures.

Another recent work described the transformation of PE, PP, and PS into methane (>97% purity) at 300–350 °C using near-stoichiometric amounts of H 2 in the presence of a Ru-modified zeolite as a catalyst [ 171 ].

6. Conclusions

Ideally, the route to achieve a sustainable society is to replace synthetic plastics. A plastic-free world, however, is presently utopistic, and great effort must be applied in the pursuit of a drastic change in end-of-life plastic waste treatment and management.

In this review, we presented a highlight of the very latest technologies being developed to enhance the recycling efficiency of polymers and to generate high-value products from plastic waste.

Mechanical recycling and chemical upcycling appear to be the most promising strategies, since incineration and landfill are more pollutant and, for the latter, plastic waste completely loses its value.

Although, in the last few years, researchers have focused on chemical treatments, mechanical recycling is still the more mature and better performing technique. The lack of adequate infrastructures and technologies is limiting the industrialization of chemical upcycling, as well as the replacement of current materials with more sustainable polymers.

Future solutions will mainly focus on the development of biodegradable materials, completely recyclable polymers, and depolymerization/repolymerization pathways that allow to maximize the plastic life cycle.

Waste is a very serious problem and is intimately related to environmental and social–economic impacts. The problem of waste must be considered holistically from governments, industries, and stakeholders to preserve human health and guarantee the world survival. A deep change in mentalities at all levels is necessary to approach the impact of humanity and the industry on the environment; therefore, a high level of information is required to achieve awareness and promote sustainable processes and products. Too much information is available today; thus, that the scientific community must help give clear and well-justified indications regarding the best technologies to be adopted in the future. The authors hope that this mini-review will contribute to this consciousness and positively impact future choices.

Overview of plastic recycling techniques.

General scheme of primary and secondary recycling processes.

PET chemical recycling routes and product desired.

Low-energy catalyzed methanolysis of PET.

PET aminolysis via monoethanolamine (MEA).

General scheme of thermal recycling processes.

Author Contributions

Conceptualization, V.B.; writing—original draft preparation, V.B., M.F., R.S., C.B. and M.A.-A.; writing—review and editing, V.B., M.F., R.S., C.B. and M.A.-A.; supervision, V.B. All authors read and agreed to the published version of the manuscript.

This research was funded by POR FESR Veneto 2014–2020 Asse 1. Azione 1.1.4 (project title: Advanced waste recovery systems–ID 10057503).

Institutional Review Board Statement

Informed consent statement, data availability statement, conflicts of interest.

The authors declare no conflict of interest.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

How to transition to more sustainable food packaging

There are many tradeoffs and factors at play when determining the ideal packaging that checks boxes for performance and environmental stewardship.

Sustainable terminology

Packaging resources  .

• BPI, the Biodegradable Packaging Institute , is a leading authority on compostable products and packaging. It has a listing of approved products and companies.
• The Environmental Defense Fund’s UP (Understand Packaging) Scorecard offers restaurants a way to compare different packaging products and assess their impact on human and environmental health. 
• PlasticScore is a consumer restaurant packaging rating site that also offers restaurants a free sustainability analysis and lets them control their ratings by recording changes they make to more sustainable packaging.
• Upstream is a change agency for reuse in the U.S. and Canada that provides information and resources on shifting from single-use to reuse. Its research report on foodservice shows cost and environmental savings of reusables compared with single-use packaging.
• The Recycling Partnership , a mission-driven NGO committed to advancing a circular
• economy by building a better recycling system.
• Rubicon provides a digital marketplace of sustainable solutions to help restaurants manage waste, composting and recycling needs.

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Lifestyle, Sustainability

Caring for the Environment: ASUS Sustainable Packaging

Oct 26, 2023

Author: ASUS    Reading time: 6 minutes

Developing sustainable packaging for our products is more than just a vision for ASUS. You may be surprised at the amount of thought and effort put into the design of our packaging - all with the goals of making it more sustainable.

Through continuous innovation of packaging materials, optimization of reusability in packaging parts, expanding cyclability of disposed packaging, and better usage of space through design, we continuously hold ourselves to our ESG promises . Read on to understand how we’re promoting sustainability with our packaging.

Table of contents

Eco-friendly packaging since 2019, eco-friendly ink and paint, reducing carbon footprint through minimalizing used space, integrating reusability into laptop packaging, asus products with innovative, eco-friendly packaging, a greener future.

We hear about “eco-friendly packaging” all the time but how exactly do we define whether packaging is “eco-friendly”? Eco-friendly packaging should be designed with environmental sustainability in mind, and minimize environmental. We have integrated reusability design to prolong our packaging’s usage.

Single use packaging is also a crucial component of packaging but can be damaging to the environment in numerous aspects. As little as 5% of it can be effectively recycled according to the research report from Ellen MacArthur Foundation in 2016. To address this issue, since 2019 ASUS replaced PE (Polyethylene) bags with PET (polyester or polyethylene terephthalate) non-woven fabric in our packaging. This material can be recycled multiple times and applied to a variety of applications, including bags or clothing.

To further reduce the use of single-use-plastics, we have continued to make improvements to the design of our laptop packaging. From 2020 to 2022, we gradually increased recycled pulp paper usage by 3,834 tons, a 22% usage increase that brought the total recycled pulp paper usage up to 21,039 tons in 2022. Now more than 90% of the materials for the packaging boxes for our laptops is made from recycled pulp, eliminating a large portion of single-use plastics like PE.

Usage of FSC™-certified packaging has been essential for us to achieve our sustainability goals. FSC™-certified packaging are materials certified by the Forest Stewardship Council™ (FSC™). The certification applies to paper made of responsibly sourced wood fiber. Usage of FSC™-certified material in our packaging has grown over 7-fold from 2020 to 2022, of which in 2022 we’ve used 71.7 tons of FSC™-certified materials.

In certain sustainability themed products like Zenbook S 13 OLED (UX5304) we have implemented a “zero plastic” design for packaging. One of the greatest hurdles we had to overcome with this goal was the handle design. After experimenting with over 20 different combinations of paper handles and paper tapes, we have created a paper handle that is durable enough to hold up to 20 kilograms of weight. This provides extra guarantee to the durability and security of carrying the outer case since the Zenbook S 13 OLED model itself is only 1 kilogram light. For more about the design of Zenbook S 13 OLED, click on the link to this article More with Less — New Thin and Light ASUS Zenbook Laptops .

In addition to using FSC™-certified paper, we use ink that is eco-friendly and non-toxic. Our ink meets the EU Directive 94/62/EC on packaging and packaging waste (PPWD), which requires packaging materials to be non-toxic not only to humans but also to the environment. We have also gone the extra mile to ensure our that the paint and ink used on our packaging worldwide meets additional requirements that are specific to certain regions. Such efforts include the following:

Low-VOCs in paint and ink

VOCs (Volatile Organic Compounds) are chemicals that vaporize easily. In 2020 we introduced low-VOCs ink for worldwide packaging to ensure safety of our employees’ working environment and physical health.

Suspension of mineral oil as a raw material and plasticizer control

In 2021 we strengthened a requirement for our suppliers to avoid use of mineral oil, which can clog pores in soil, causing degradation. The prohibition of mineral oil is an imposed regulation in France only, but ASUS has made an effort to remove it from our worldwide distribution to avoid potential harm to our customers.

Plasticizers – or Phthalates - are used to soften ink to increase its flexibility and adherence. However, this chemical can be hazardous and cause hormonal imbalance or allergies, so we further restricted its usage in our print.

Phasing out PAHs

Polycyclic aromatic hydrocarbons (PAHs) are a material which consists of the spray paint used on the laptop keyboard and outer coating. This chemical can potentially cause cancer if inhaled or absorbed through human skin. We are currently phasing out this chemical from our paint and ink.

The compact design of our laptop packaging not only lowers transportation cost and carbon emission thanks to saved space and reduced weight, it also contributes to eliminating single-use cushioning materials completely. You will not find any bubble wraps, rolled foam, air pillows, or anything of that sort in our laptop packaging - because we have designed the box to closely “hug” the laptop and included accessories.

Our packaging is carefully designed and stacked to achieve the slimmest, most compact box possible. For instance, we have successfully shrunk our packaging volume by up to 12% for our latest generation of monitor displays. This contributes to space utilization and makes transportation 19% more efficient, which further reduces carbon footprint.

Normally when we find cardboard or plastic components in a product’s packaging, we tend to throw it out and get it recycled immediately – but what if the parts could be functional? We have integrated reusability functions to packaging parts of our Expertbook B9 (B9400) and Expertbook B9 OLED (B9403) . These creative designs prolong the packaging’s lifespan and enhances its functionality.

The purpose of reusability design according to The Circular Design Guide by the Ellen MacArthur Foundation and IDEO is to innovate and create new ways to be more sustainable and resilient and provide long-lasting value. Taking our compact packaging a step further, we have designed parts of our packaging structure to be functional. Cardboard parts like the laptop holder in our packaging can also be assembled into an ergonomic laptop stand to prop up the laptop during usage, and even provide card holding or storage purposes. Now that’s what you call a win-win when waste is reduced and the cost for purchasing a new laptop stand is saved!

The packaging of our Expertbook B9 and Expertbook B9 OLED are designed to bring reusability to consumers. It can contain key parts and serve as a laptop stand.

As we work to develop completely recyclable packaging for more and more products, we are proud to highlight some of the ASUS products that already feature thoughtful, eco-friendly packaging. A few examples are as follows.

The packaging of ROG Phone 6 BATMAN Edition uses EPP material (high crystalline polypropylene) which can be 100% recycled. This material is a bead foam which is widely used in the automotive industry and for packaging. It can be broken down and recompressed for reuse, making it fully recyclable without producing additional toxic substances. EPP packaging is also lightweight and, as a result, reduces carbon emission when products are transported.

We took sustainable packaging a step further in the next generation of ROG phone – our ROG Phone 7 Ultimate . Besides having an edgy, futuristic design shaped like an onigiri, the octagonal box of the phone is made using agricultural byproducts like sugarcane, plant stalk, leaves, and other discarded organic materials. The result is a completely biodegradable packaging.

Recycled packaging is also used in our ROG Raikiri series controllers - ROG Raikiri Pro & ROG Raikiri . We produced the product’s box with 100% recyclable wet-molded pulp that neatly conforms to the controller, achieving a fully recyclable packaging that’s plastic and adhesive free.

Making our business model more sustainable is an ongoing journey, but we have made impressive progress. To learn more about our sustainability-related efforts, check out How ASUS Helps Sustain an Incredible, Greener Future

Now, next time you unbox a product from ASUS, you’ll know that immense care and thought has gone into even the packaging.

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• How ASUS Helps Sustain an Incredible, Greener Future

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Apr.21 2023

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