While advances have been made in plastics recycling technologies, it still faces many challenges. Plastic waste is now ubiquitous in our natural environment, and currently about 400 million tons of plastic waste is produced every year. An astounding 91% of plastics produced from 1950 to 2015 were not recycled, according to a 2017 study. Instead, 12% of these plastics were incinerated, while the bulk—79%—were sent to landfills or left in the environment, where it can take decades to millennia to degrade.
Also, only clean plastics (such as those without food residues) can be recycled, and the recycling process itself is energy intensive and costly. This means that, for a manufacturer, it is often more economical to buy new, cheaper plastic than it is to use recycled plastic.
Meanwhile, the global plastic market is expected to grow significantly at a compound annual growth rate (CAGR) of 4% to 5% to 2030. This means the value of the global plastics market, which was $712 billion in 2023, could grow to more than $1.050 trillion by 2033, according to statistica.com.
Given the insatiable demand for plastic, there is keen interest in new recycling technologies. The Earth & I talked to Novoloop CEO Miranda Wang to discuss the Menlo Park, California-based company’s innovative approach to plastic waste “upcycling” and its potential impacts on the recycling industry once it is established at scale.
Thermoplastics versus Thermosetting Plastics
To understand upcycling, a brief review of the plastics landscape is in order. There are seven different types of plastics [see The Earth & I August 2023 article, "Keeping Plastics Out of Landfills and Public Spaces"], each with varying physical and chemical properties.
Plastics are advantageous from an industrial perspective, given their low production costs, light weight, high chemical stability, durability, high impact resistance, and good electrical insulation. Their versatility makes them ubiquitous in the production of a wide variety of manufactured goods and packaging.
Most plastics produced—around 75%—are thermoplastics, known for their malleability at high temperatures and stability once cooled. Thermoplastics include polyethylene and polystyrene (PS) in the form of single-use plastics, as well as polyvinyl chloride (PVC) and polycarbonate (PC). In theory, thermoplastics can be melted and remolded continuously to produce recycled plastic material.
Most plastics produced—around 75%—are thermoplastics, known for their malleability at high temperatures and stability once cooled; these include polyethylene and polystyrene (PS) in the form of single-use plastics, as well as polyvinyl chloride (PVC) and polycarbonate (PC).
In reality, however, thermoplastic pollution is proving to be a major environmental problem, particularly the prevalence of microplastics in the water cycle (as in the microplastic cycle). The incineration of thermoplastics can generate energy, although at the cost of greenhouse gas emissions and toxic substances in open field situations.
The remaining 25% of plastics are thermosetting plastics (thermosets), which generally cannot be recycled given how they typically burn when heated. Examples of thermosets include polyester, epoxy, and phenolic, and, given their durability and heat resistance, thermosets are found in cars and electrical appliances. There is also research underway to produce recyclable thermosets, such as through additives or photopolymerization. Thermosets are not thrown away as often into the environment as thermoplastics given their enhanced durability.
Types of Plastic Recycling
Currently, the recycling industry mostly considers mechanical recycling to be the foremost approach to recycling plastic waste. Mechanical recycling is used to recycle thermoplastics, such as polyethylene terephthalate (PET) and high-density polyethylene (HDPE). This involves collection, washing, first and second sorting, shredding, and extrusion (reforming into plastic pellets). These pellets are then used to manufacture new products. Challenges in mechanical recycling include polymer scission, lack of sorting methods at scale, and inconsistent product quality, although it can be the most effective in terms of time, economic cost, and environmental impact.
Chemical recycling … utilizes a number of technologies in which the chemical structure of the plastic is altered, including pyrolysis, gasification, hydro-cracking, and depolymerization, such as for PET, nylon (PA), polyurethane (PU), and polypropylene (PP).
Chemical recycling is becoming more popular given its scalability of operations. This approach utilizes a number of technologies in which the chemical structure of the plastic is altered, including pyrolysis, gasification, hydro-cracking, and depolymerization, such as for PET, nylon (PA), polyurethane (PU), and polypropylene (PP). Dissolution of plastics in solvents (solvolysis) is also included in depolymerization, such as through hydrolysis, glycolysis (ethylene glycol), acidolysis (acids), and alcoholysis (methanol). Challenges in chemical recycling include potential toxic and hazardous byproducts being released into the environment.
Finally, organic recycling (or biological recycling) utilizes microbiological treatment, either in an aerobic environment (a composting process) or an anaerobic environment (utilizing biogasification). Challenges in biological recycling include high start-up costs, limited applications of enzymes, and potential risks of using enzymes.
Plastic Upcycling and Novoloop
Given the limitations of recycling alone, research is underway on upcycling (the conversion of “by-products or waste products into valuable and new materials”) to convert post-consumer plastic waste into valuable products—such as footwear, automotive materials, and sporting goods. In a review of chemical upcycling methods, there have been numerous examples of using metal catalysts for depolymerization under high pressure conditions.
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Meanwhile, Wang has indicated that the company has been working on upcycling polyethylene over the past eight years and is now nearing completion of the planning phase for its first industrial facility. A proprietary four-step process called accelerated thermal-oxidated decomposition (ATOD) is used to produce materials for shoes and bonding products from polyethylene.
E&I: What is Novoloop’s innovation in upcycling plastic waste?
Miranda Wang: “Novoloop is the original developer of a novel chemical technology to transform hard-to-recycle plastic waste into performance materials. We oxidize polyethylene into chemical building blocks; then we harvest, purify, and build back up into a platform of materials that are indistinguishable from normal plastics made from fossil fuels. The formation of monomers is achieved through the addition of oxygen, which means that the mass of monomers produced can exceed the mass of plastic waste entering the process. Novoloop has demonstrated that we can reproducibly exceed 100% yields using the ATOD process.”“After monomers are created from digesting polyethylene, we implement a robust purification process that allows us to harvest virgin quality monomers for further processing. Because we build our intermediates and polymers out of virgin quality monomers, the quality of our products are high performance and consistent.”
E&I: How effective is ATOD?
Miranda Wang: “ATOD takes polyethylene and digests it over three to four hours and reliably makes chemical monomers for performance materials. We have successfully run this chemistry process more than a thousand times in the lab at various scales, and it has been successfully replicated by three separate contract manufacturers. We're now building a continuous integrated pilot plant for it and the support systems enabling cost competitive operations.”
“What sets us apart … is our ability to upgrade commodity plastic waste into virgin quality performance materials worth 40 times more. We offer chemically upcycled products at quality and price parity to fossil-based virgin materials while delivering a significant carbon reduction.”
E&I: What is unique about ATOD?
Miranda Wang: “What sets us apart from existing recycling solutions is our ability to upgrade commodity plastic waste into virgin quality performance materials worth 40 times more. We offer chemically upcycled products at quality and price parity to fossil-based virgin materials while delivering a significant carbon reduction. Novoloop holds 51 patents worldwide and is uniquely advantaged over other chemical recycling.”
“Novoloop offers a range of products from dicarboxylic acid monomers, polyol intermediates, and thermoplastic polyurethane resin. These are all made through Lifecycling post-consumer polyethylene using our ATOD technology. Our monomers and intermediates can be used to make products with total addressable markets of $140B, including various polyurethanes, coatings, and nylons.”
E&I: How will your process be implemented on an industrial scale?
Miranda Wang: “We are building chemical operations (plants) around the world to transform plastic waste from that region into monomers. Then, by partnering with a network of existing capacity in the industry, we build back up those monomers into various chemical and performance material products, which we sell around the world. We are in early stages of planning our first commercial factory. Tentative timelines point to a first project operational in 2027.”
E&I: What are environmental considerations you have made for your process and factory? What are the implications once the factory is up and running?
Miranda Wang: “Based on our ISO-compliant lifecycle assessment, each 20,000-metric-ton (plastic intake capacity) deployment increases our impact, diverting an additional 20,000 tons of plastic waste, preventing 120,000 tons of carbon emissions, and saving 66,000 L [about 17,435 gal] of water per year. Novoloop recovers and recycles the predominant waste products back into the system.”
A Pressing Challenge
Given the rate of the growth of the plastics industry and the relative ineffectiveness of current recycling approaches, it would be easy to become despondent about the idea of a waste-free world. However, Novoloop’s entry into the recycling industry with a new and innovative approach shows that humanity’s capacity to adapt and develop new ways of solving global trash problems isn’t exhausted.
*Robin Whitlock is an England-based freelance journalist specializing in environmental issues, climate change, and renewable energy, with a variety of other professional interests, including green transportation.