Chemical recycling technologies can have significant climate benefits compared with virgin resin production, landfilling and waste-to-energy incineration, according to a new study.
The Oct. 12 study from the City College of New York, which was commissioned by the American Chemistry Council, said the technologies can process hard-to-recycle plastics into new products in a more climate-friendly way than using virgin resources.
"As advanced recycling becomes increasingly efficient, it is poised to play a major role in achieving global sustainability goals," said Marco Castaldi, an author of the study, professor of chemical engineering and director of CCNY's Earth Engineering Center.
"It can transform hard-to-recycle plastics into a multitude of high-value feedstocks, reducing the need for fossil resources and limiting the environmental impact of waste management," he said. "Equally important, the data suggest that our transition to a more circular economy will dramatically improve climate outcomes."
The report looked at 13 life cycle assessments for the technologies, which it refers to as advanced recycling.
It said that while results vary based on processes and materials, it said advanced recycling can reduce the need for fossil energy resources by up to 97 percent compared with landfilling.
As well, it said the technologies can reduce carbon dioxide emissions by more than 100 percent in some cases, "when accounting for displaced demand for chemical products and energy."
The CCNY study, however, did not seem to directly compare chemical recycling processes to traditional mechanical recycling technologies.
Other studies have found a lower carbon footprint for mechanical recycling for plastics vs. chemical recycling.
A late September study from Zero Waste Europe, for example, found that pyrolysis, one of the more common chemical recycling technologies, can have greenhouse gas emissions that are nine times higher than mechanical recycling.
That study used data prepared by consultants for the European Commission.
The CCNY study noted at one point that there are limits on the number of times a material can be mechanically recycled.
"Since limitations exist and plastic materials that are mechanically recycled several times eventually lead to portions being disposed or combusted, it is imperative to fully understand the technologies and how they are deployed," the CCNY study said.
In a fact sheet released with the study, ACC argued that advanced recycling can process materials that mechanical recycling cannot.
"Multiple AR [advanced recycling] technologies can process hard-to-recycle plastics that cannot feasibly be recycled through traditional methods," ACC said. "Since these advanced recycling technologies create raw materials that can be remade into new plastics and products, AR allows plastics to be reused again and again."
The CCNY report said it looked only at LCA studies published since 2020.