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CU chemists discover process to recycle plastic bottles with electricity

Odds are, even when these go into the recycling bin, this plastic won't get recycled. According to the U.S. Department of Energy, only 5% of plastic in America gets recycled. The other 86% ends up in landfills and the remaining 9% is incinerated.
Posted at 8:59 AM, Jul 10, 2023

BOULDER, Colo. — Researchers at the University of Colorado Boulder have achieved a major breakthrough in plastic recycling, using electricity and chemical reactions to break down bottles and other packaging into their individual building blocks which can then potentially be reused in new products.

Professor Oana Luca and graduate student Phuc Pham were inspired to use their expertise and passion to address the crisis of plastic waste in our environment, and have spent the last six months experimenting for a solution. The United States goes through millions of tons of plastic every year, and only about 5% of it is successfully recycled, according to Greenpeace.

“When you’re a hammer, everything looks like a nail. When you’re a chemist, everything looks like molecules,” said Oana Luca, assistant professor of chemistry at CU Boulder. “We’re motivated by the increased accumulation of plastic waste to the environment, and I think there needs to be a solution to the current crisis. And, we want to contribute to it.”

The solution came from within small reactors in their campus lab.

Using electrochemical reactions and a “single electron reducing agent,” the researchers have successfully broken down plastic bottles into their molecular components. Professor Luca likened the process to Legos—if you were to picture your plastic water bottle as being composed out of Lego bricks, this electrochemical process essentially takes the bricks apart. They can then be used again to build another bottle (or other plastic product), rather than being “downcycled” into a single-use shopping bag.

“I feel like this is an example of using molecular organic chemistry at the most basic of levels, for good,” Luca said.

Their current process works on polyethylene terephthalate (“PET”) plastics, which are clear and lightweight and commonly used in bottles and packaging. Many other types of plastics need to be better recycled as well, though, and that’s where Luca and Pham have their sights set now. They also want to keep fine-tuning their existing process, so that it can be recreated at larger scales.

“I am very interested in doing any kind of plastic recycling,” Pham said. “I hope that we can scale the reaction up so one day it can be applied on an industrial level.”

“There are so many polymers and materials out there that people aren’t recycling at all. They’re not being collected,” Luca added. “This is the beginning of many, many, many different kinds of chemistries.”