Demystifying Chemical Recycling: An Emerging Solution or a New Set of Challenges?
The escalating plastic pollution crisis and inefficiencies in the plastic recycling system have turned many against single-use plastics and led to national and state bans on some plastic packaging. Now, the fossil fuel and petrochemical industries have launched a category of plastic processing technology called chemical recycling or advanced recycling. The plastic industry describes it as a potential panacea that can clean up millions of tons of plastic waste produced annually. Is it everything claimed?
The Ocean Conservancy recently hosted a forum to discuss their findings after examining chemical recycling. The implications of this technology are intricate, and the technology is still evolving. However, the early evidence is that chemical recycling still requires immense energy, generating large amounts of planet-warming CO2. At the same time, it does not significantly reduce the volume of plastic toxins.
“Chemical recycling is an umbrella term that captures a suite of disparate technologies,” said Dr. Anja Brandon, Associate Director of U.S. Plastics Policy at the Ocean Conservancy. She suggested that fossil fuel and plastic companies fudge these terms to confuse consumers and policymakers. “These terms are constantly changing. Its ‘chemical recycling,’ ‘advanced recycling,’ ‘molecular recycling,’ and ‘renewable technologies.’ Different companies all use different terms.”
One clear message from the event was the importance of reducing the use of plastic. As much as 40% of plastic becomes single-use packaging, which accounts for much of the plastic pollution in the oceans and landfills.
“Recycling mitigates the harm of waste and extraction, but not as much, of course, as reuse and certainly reduction is our primary strategy,” said Lynn Hoffman, Co-President of Eureka Recycling in Minneapolis and National Coordinator for the Alliance for Mission-Based Recyclers.
Hoffman noted that mechanical recycling is not without its environmental flaws but suggests that most plastics, especially single-use plastic packaging, are not recycled because of the broken economics of today’s system. It’s often cheaper to use virgin plastic because of the complexity and cost of sorting and processing plastic.
Chemical Recycling: The Spectrum of Methods
Chemical recycling describes several technologies, each a method of breaking down plastics categorized into three main types: purification, depolymerization, and conversion technologies. Each process converts the polymers in plastic into their underlying monomers, the hydrocarbon building blocks extracted from petroleum.
Purification
This method involves using solvents or heat to dissolve plastic, separating it from additives and impurities without altering its molecular structure. The recovered plastic can then be reprocessed into new materials. This method requires very clean post-consumer plastic supplies, which requires careful sorting and cleaning before the material can be processed. Purification works only with specific types of plastic.
Depolymerization
This process breaks plastic down into its constituent monomers using solvents, heat, catalysts, or enzymes. Like purification, depolymerization requires pure feed-stocks, and there are limits on the types of plastics that can be run through the process.
Conversion Technologies
Two older technologies, pyrolysis and gasification, are being repurposed and rebranded under the chemical recycling banner. Both rely on extreme heat to “crack” the polymers, breaking them down into hydrocarbon monomers. And most of that heat is produced by burning oil, coal, or natural gas.
Pyrolysis relies on intense heat and pressure to break plastic molecules into shorter-chain hydrocarbons, not monomers, resulting in a substance known as pyrolysis oil. This process is energy-intensive, requiring temperatures between 600 to 1,600 degrees Fahrenheit.
Like pyrolysis, but operating at even higher temperatures between 1,000 and 2,000 degrees Fahrenheit, gasification breaks plastic into synthetic natural gas.
Chemical Recycling Impacts and Policy Considerations
Despite its potential to address the plastic pollution crisis, chemical recycling has significant environmental and social impacts, especially concerning carbon emissions. Current data suggests that the carbon footprint of chemical recycling is significantly higher than that of traditional mechanical recycling that grinds and melts plastic for reuse. Because chemical recycling facilities are built near oil refineries and plastic factories, they are usually next to low-income communities of color. The emissions and other toxins these chemical recycling facilities may produce raise critical questions about the technology’s role in a sustainable future.
The Ocean Conservancy panelists said that policy implications also need to be at the forefront of the discussion. The classification and regulation of chemical recycling facilities, whether treated as manufacturing entities or solid waste management facilities, have significant implications for where they are placed and the reviews required for permitting. So far, 24 states in the U.S. have passed laws reclassifying chemical recycling facilities as manufacturing entities. In other words, these states decided it is not a form of recycling.
The Challenges of Tracking Success and State Laws
Tracking the success of chemical recycling is a complex task, because the oil and gas produced is not directly comparable to recycled plastic.
The recycling industry has long relied on mass balance accounting, which compares the volume of materials sent to a recycling facility with the output. That works well for mechanical recycling, which ingests plastic and produces plastic that is weighed to estimate the percentage of materials recovered. However, because chemical recycling turns a solid plastic into an oil or gas, there is no easy way to estimate yields. Consequently, petrochemical companies can make audacious claims about the efficacy of chemical recycling that cannot be compared with mechanical recycling.
State laws will play a crucial role in shaping the recycling landscape. They help finance improvements in recycling systems and establish accountability for producers of packaging materials. However, how chemical recycling is defined and regulated by different states varies. California, for example, excludes chemical recycling, treating it as a form of manufacturing rather than recycling. On the other hand, Oregon may treat chemical recycling as a waste management practice but imposes a high burden of proof that the technology is effective before allowing a facility to operate.
Addressing the Textile Industry and Community Impacts
The ever-growing issue of textile waste, particularly from fast fashion, has made chemical recycling appear to be an attractive solution. Startups are exploring depolymerization to tackle the challenge of recycling polyester materials. However, as Dr. Brandon notes, the priority should be reducing production and consumption.
Chemical recycling facilities, like all recycling operations, have proven environmental and health impacts. As the technology evolves, it may become cleaner. For example, oil companies have suggested the CO2 emitted by depolymerization and conversion processes may be captured by a scrubber and sequestered permanently. The potential to extract additives and other impurities from mixed plastic waste using purification could produce more food-grade plastics, albeit at the potential cost of more plastic packaging.
But do we need more plastic? By reducing plastic use, society can remove a substantial amount of the problem. That’s a question each of us answers when we are shopping.
Chemical recycling’s effectiveness, environmental impacts, and societal implications require careful consideration and transparent discussion. As humanity strives to create a sustainable future, the panelists emphasized that all options must be assessed carefully with a critical eye to ensure that solutions like chemical recycling are responsibly and equitably implemented.
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