Molecular recycling could change the game when it comes to reusing plastics

Sustainability |  4 min. read

For most people, recycling ends when they drop the plastic water bottle or to-go-lunch container in the recycle bin. Most of us don’t think twice about it – or we assume that the next container we pick up is made up of recycled bits of plastics that we used last month or last year.

In fact, the recycling process is much more complex. For decades, collecting and sorting different plastics for recycling has been complicated and time-consuming, leading much of America’s recyclable plastic materials to be shipped overseas to China or, worse, sent directly to landfills, limiting the plastic to a single lifecycle.

With an increased focus on sustainability and the goal of making each molecule of plastic last for multiple use cycles, America’s petrochemical industry is looking at molecular recycling as a way to give the items we use every day a new life. They know, as consumers demand, that it’s time to turn today’s problem into tomorrow’s solution.

Is molecular recycling the future?

A number of leading companies, along with startups, are now pursuing molecular recycling, with its seemingly endless opportunities and applications, as a scalable way to improve recycling and make plastics last longer than their single-use lives today.

Chemists and engineers are innovating new plastics that can be broken down and reused without compromising the properties that made them attractive and in high demand.

Molecular recycling involves stripping down plastic (i.e., breaking apart polymer molecules) to fundamental building blocks known as monomers (the individual units that link up to make polymers), refashioning them back into polymers in the form of pellets. Amazingly, this process can be repeated multiple times without losing strength or quality. This is where molecular recycling has significant advantages over the mechanical recycling methods that are currently used broadly today.

Overcoming recycling challenges

Most plastics recycling now undergoes a mechanical process where the plastic is shredded and melted down into new pellets. Unfortunately, that process is hard to scale up, has high infrastructure and operations costs, and weakens the plastic over time. Weakened quality also limits how much recycled plastic can be included in new products.

There are challenges to any recycling approach, including that different plastics require different approaches. That is compounded by the fact that comingled recycling, prevalent for most home-recycling programs across the United States, usually needs to be sorted to prevent process contamination. Additionally, food and packaging residue on the recycled materials can render the melted product unusable.

SABIC is working on an effort, in partnership with Plastic Energy, to recycle these so-called tainted plastics into clean, new wrappings for food products, instead of sending it to landfills or incinerators. Together, with mechanical recycling, molecular recycling can make a dent toward the vision of recycling most of us have in our minds. Molecular recycling, as companies are showing, will improve and innovate, with the potential to overcome these barriers.

“Chemical recycling can complement mechanical recycling by diverting plastic waste from landfill or incineration, creating a full circular economy of plastics,” Plastic Energy CEO Carlos Monreal told Plastics Today.

Industry leaders taking action

To move forward with a more robust, sustainable recycling process that ensures multiple lives for each piece of plastic, a number of petrochemical companies are taking bold new steps.

Americas Styrenics and Agilyx have partnered together to convert used polystyrene into new styrene monomer, despite the difficulty that polystyrene presents to traditional recycling. Agilyx has also teamed up with Toyo Sterene for a plant in Japan that, when complete, will have capacity to process 10 tons of polystyrene a day into recycled monomer.[2] And, SABIC is investing in a system to convert comingled, mixed-quality plastics into new products.

Meanwhile, LyondellBasell and SUEZ joined forces to form QCP, developing recycled resins that have the strength, quality, and price to compete with new plastic materials. SUEZ is one of the largest waste collection companies in Europe, giving the partnership a real opportunity at scaling these innovations to a significant population.

At its plant in Illinois, BP is researching new technology to pilot chemical recycling previously un-recyclable plastics into new feedstocks. Dow Chemical and ExxonMobil are taking action too, with Dow using a pyrolysis oil feedstock (similar to naphtha), made from recycled plastic waste, to produce polymers at a plant in the Netherlands and ExxonMobil recently introduced new polyethylene materials that will make it easier to recycle laminated packaging used in a number of cartons, cups, and food containers.

“We believe plastics are too valuable to be lost as waste and should be part of the circular economy,” Diego Donoso, business president for Dow Packaging & Specialty Plastics, said to Recycling International.

INEOS has made headway on creating new styrene monomer from used polystyrene and Eastman has new technology to recycle mixed plastics by oxidizing them and converting it back into material that the company can use to create their products.

A more sustainable future

Molecular recycling can drive us to a world where that plastic bottle we now toss away does not become waste but instead is returned to its original raw material state where it is reused again, and again in more sustainable and useful ways. That indeed may hold the key to solving the plastic waste challenge and creating a more sustainable future.

“U.S. petrochemical producers are committed to the plastic waste issue and are at the forefront of addressing the problem,” said Chet Thompson, president and CEO of the American Fuel and Petrochemical Manufacturers. “They’re developing innovative products, investing in new and advanced recycling methods, and collaborating closely with other stakeholders in the plastics and recycling supply chains.”


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