Nature is full of interconnected loops. Water travels in a never-ending cycle, going from the ground to the sky and back again. When living things die and decompose, elements such as carbon and nitrogen are absorbed by Earth’s crust and used to create new life. These systems of nature are closed loops, meaning they are self-sustaining, and they have no beginning or end.
Humans exist within these cycles; like all living things, we both influence and benefit from them. But the ways in which we currently manage our waste are anything but sustainable or circular.
Researchers at Argonne National Laboratory, a U.S. Department of Energy lab affiliated with the University of Chicago, are working toward a more regenerative future — one where Earth’s resources are circulated sustainably. In this type of economic system, called a circular economy, a product’s end of life is planned for at the design stage. This way, would-be waste becomes a valuable resource for creating new or refurbished products.
Argonne and UChicago scientists are developing methods to recover and reuse precious metals and other valuable materials from batteries and devices at their end of life. They’re also developing technologies to turn waste into valuable commodities. And by collaborating with industry partners, other research institutions and local communities, they’re helping to bridge the gap between laboratory discovery and large-scale societal impact.
Closing the trash-to-treasure loop
The emissions humans produce and the plastics, devices, food and other waste we discard do not always get folded back into Earth’s natural cycles.
Instead, much of our waste is either left sitting in rapidly growing landfills, polluting the environment or both. Meanwhile, our emissions are accumulating in the atmosphere, driving rising global temperatures and damaging ecosystems. And despite our efforts so far, less than 10% of the approximately 7 billion tons of plastic waste ever generated has been recycled.
To address this problem, we can take steps to move towards a circular economy instead. A circular economy turns industrial waste into feedstock for the creation of new products. This means viewing landfills less like putrid, mountainous eyesores and more like massive treasure troves waiting to be mined for their stores of valuable materials.
“Plastic contains a lot of energy. It’s like pre-purified crude oil, and it’s already out of the ground,” said Max Delferro, a chemist with Argonne and the UChicago Pritzker School of Molecular Engineering, and Argonne’s Circular Economy lead. “In the future, as technologies improve, there could be a financial incentive to digging for plastic in landfills.”
Delferro and his team at Argonne are pioneering new and improved methods for recycling plastic waste. For example, they are using chemical tools called catalysts to convert plastic bags and films into higher-value products, such as lubricants and waxes. They’re also reimagining how plastic products are designed to begin with.
For example, as part of the Department of Energy’s Institute for Cooperative Upcycling of Plastics (iCOUP), Delferro and other scientists from Argonne and Cornell University developed a new method for recycling high-density polyethylene, or Type 2 plastic. Their technique transforms postconsumer products into a new type of plastic material that can be recycled repeatedly without loss of quality.
Wanted and unwanted
Even society’s stinkier waste streams can be used as valuable feedstock. Argonne scientist Meltem Urgun Demirtas is researching ways to recover resources from food waste and sludge generated from cities, wastewater treatment plants and industrial processes. In the lab, she and her team have experimented with waste from local restaurants, pig farms, breweries, cheese producers and even their own homes.
“My motivation is to clean up the world,” said Urgun Demirtas, who leads Argonne’s Sustainable Materials and Processes department. “Anything that nobody wants in their backyard or in their city is of interest to me.”
—Prof. Jacqueline Stewart
