Revolutionary Recycling Process Transforms Plastic Waste

(U.S. Department of Energy) Despite millions of Americans depositing their plastic waste into recycling bins, much of that waste, including flexible films, multilayer materials, and colored plastics, cannot be recycled cost-effectively. In fact, only 9% of plastics in the U.S. are actually re-used and are typically “low-value,” meaning the high costs of recycling do not necessarily yield good returns.

Thanks to a new process from the University of Wisconsin (UW) – Madison, chemical engineers can now transform plastic waste into “high-value” chemicals, increasing the economic incentives for plastic recycling and creating novel pathways to recycle new types of plastics. In research published in Science, investigators led by Dr. George W. Huber, a professor of chemical and biological engineering at UW-Madison and Director of the Center for the Chemical Upcycling of Waste Plastics (CUWP), have developed a new plastics recycling method based on two chemical processes: pyrolysis and hydroformylation.

“Currently, there are limited options for cost-effective plastic waste recycling, and most generate a product with substantially lower value and quality than a virgin plastic,” says Dr. Gayle Bentley, U.S. Department of Energy (DOE) Bioenergy Technologies Office (BETO) Technology Manager for CUWP. “This exciting new technology paves the way for truly sustainable plastics and a circular plastics economy.”

Researchers estimate these processes will not only revolutionize plastics recycling, but could also reduce greenhouse gas emissions from the conventional production of these industrial chemicals by roughly 60 percent. “There are so many different products and so many routes we can pursue with this platform technology,” says Huber. “There’s a huge market for the products we’re making. I think it really could change the plastic recycling industry.”

Excerpt from The Guardian: When a microbe was found munching on a plastic bottle in a rubbish dump, it promised a recycling revolution. Now scientists are attempting to turbocharge those powers in a bid to solve our waste crisis. But will it work?

In 2001, a group of Japanese scientists made a startling discovery at a rubbish dump. In trenches packed with dirt and waste, they found a slimy film of bacteria that had been happily chewing through plastic bottles, toys and other bric-a-brac. As they broke down the trash, the bacteria harvested the carbon in the plastic for energy, which they used to grow, move and divide into even more plastic-hungry bacteria. Even if not in quite the hand-to-mouth-to-stomach way we normally understand it, the bacteria were eating the plastic.

The scientists were led by Kohei Oda, a professor at the Kyoto Institute of Technology.

But these bacteria were doing much more than that – they appeared to be breaking down plastic fully and processing it into basic nutrients.

In the years after their discovery, Oda and his student Kazumi Hiraga, now a professor, continued corresponding and conducting experiments. When they finally published their work in the prestigious journal Science in 2016, it emerged into a world desperate for solutions to the plastic crisis, and it was a blockbuster hit. Oda and his colleagues named the bacterium that they had discovered in the rubbish dump Ideonella sakaiensis – after the city of Sakai, where it was found – and in the paper, they described a specific enzyme that the bacterium was producing, which allowed it to break down polyethylene terephthalate (PET), the most common plastic found in clothing and packaging. The paper was reported widely in the press, and it currently has more than 1,000 scientific citations, placing it in the top 0.1% of all papers.

But the real hope is that this goes beyond a single species of bacteria that can eat a single kind of plastic. Over the past half-century, microbiology – the study of small organisms including bacteria and some fungi – has undergone a revolution that Jo Handelsman, former president of the American Society for Microbiology, and a science adviser to the Obama White House, described to me as possibly the most significant biological advance since Darwin’s discovery of evolution. We now know that micro-organisms constitute a vast, hidden world entwined with our own. We are only beginning to grasp their variety, and their often incredible powers. Many scientists have come around to Oda’s view – that for the host of seemingly intractable problems we are working on, microbes may have already begun to find a solution. All we need to do is look. READ MORE