A French company is using enzymes to recycle one of the most common single-use plastics


Since single-use plastics are largely derived from petroleum, by 2050 plastics could represent 20% of the annual oil consumption in the world. Reducing our dependence on plastics and finding ways to reuse the plastic that is already in the world could greatly reduce emissions.

Right now, just about 15% of all plastics around the world they are collected for recycling every year. Researchers have been trying since the 1990s to find new ways to break down plastics in hopes of recycling more. Companies and researchers have worked to develop enzymatic processes, such as the one used in Carbios, as well as chemical processes, such as the method used by Loop Industries. But it was only recently that enzymatic and chemical processes began to be commercialized.

Carbios’s new reactor measures 20 cubic meters, about the size of a cargo van. It can hold two metric tons of plastic, or the equivalent of about 100,000 bottles ground at a time, and break it down into the basic components of PET (ethylene glycol and terephthalic acid) in 10 to 16 hours.

The company plans to use what it learns from the demonstration facility to build its first industrial plant, which will house a reactor about 20 times the size of the demonstration reactor. That large-scale plant will be built near a plastic manufacturer somewhere in Europe or the US, and should be operational by 2025, he says. Alain marty, Scientific Director of Carbios.

Carbios has been developing enzyme recycling since the company was founded in 2011. Its process relies on enzymes to crush the long chains of polymers that make up plastic. The resulting monomers can be purified and joined to make new plastics. The Carbios researchers started with a natural enzyme used by bacteria to break down leaves, then modified it to make it more efficient at breaking down PET.

Carbios demonstration facility in Clermont-Ferrand, France. Image courtesy of SkotchProd.

Carbios estimates that its enzymatic recycling process reduces greenhouse gas emissions by approximately 30% compared to virgin PET. Marty says he expects that number to increase as they fix the problems.

In a recent report, the researchers estimated that making PET from enzymatic recycling could reduce greenhouse gas emissions by between 17% and 43% compared to making virgin PET. The report did not refer specifically to Carbios, but it is probably a good estimate for your process, according to Gregg beckham, a researcher at the US National Renewable Energy Laboratory and co-author of the report.

While the development of new enzymes has been a major focus of new research and commercial efforts, other parts of the process will determine how efficient and cost-effective the technology will be, says Beckham, who leads a consortium on new methods of production and recycling of plastics.

“They’re all the less glamorous things,” Beckham says, like making the plastic in a way that enzymes can break down efficiently or separating what the enzymes spit out, which can take a lot of energy and time, and increase the emissions and costs. .


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