RESEARCH NEWS
Researchers Will Develop Green Technology to Recycle Refrigerants That Drive Climate Change by Brendan Lynch
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efrigerants inside the air conditioner that cools your house or apartment are extremely powerful greenhouse gases. Used widely in domestic and commercial cooling systems, commonplace refrigerants called hydrofluorocarbons (HFCs) such as R-410A have a global-warming potential roughly 2,000 times greater than the carbon dioxide emitted from vehicle tailpipes. Recent legislation restricts using some HFC refrigerants in particular applications and mandates their eventual phaseout, but with millions of tons of HFCs used today around the world, how can they be disposed of without harming the environment? Venting or incinerating them would be wasteful and could accelerate climate change. Now, Project EARTH (Environmentally Applied Research Toward Hydrofluorocarbons), a new research project headquartered at the KU School of Engineering, will develop technology to separate and recycle HFC refrigerant mixtures. Supported by a four-year, $2 million grant from the National Science Foundation, Project EARTH collaboration comprises four universities — KU, Notre Dame, Texas A&M and Rutgers — along with several private corporations, Oak Ridge and Brookhaven national laboratories, and the National Institute for Standards and Technology (NIST). “We’re going to look at how to separate hydrofluorocarbon refrigerant mixtures so the low-global-warming potential (GWP) components can be reused and the high-GWP components converted into new products that are safe for the environment,” said Mark Shiflett, Foundation Distinguished Professor in KU’s Department of Chemical & Petroleum Engineering, who is leading Project EARTH. “In your house, these would be the refrigerants in your air conditioner such as R-410A,” he said. “It’s actually a mixture of two components — one of the components has a relatively high global-warming potential called HFC-125, and the other one, called HFC-32, does not. However, they are very difficult to separate because they form what is called an azeotropic mixture. Today, that refrigerant would have to be incinerated to dispose of it, and our goal is to be able to separate those two refrigerants back into their pure components and be able to reuse HFC-32 in new low-GWP products, and the other, HFC-125, we are working on converting it into a lower global warming potential product that is safer for the environment.”
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Mark Shiflett
According to the researchers working on Project EARTH, the U.S. market alone for recycling refrigerants is valued at more than $1 billion. Furthermore, reducing the release of high-GWP refrigerants into the Earth’s atmosphere is equivalent to eliminating 175 million metric tons of carbon dioxide, or the yearly emissions from 50 million cars. The crux of Project EARTH will focus on high-fidelity experiments, advanced computer simulations and rigorous analysis to synthesize and test a new type of fluid called an “ionic liquid” that could be used to separate, recycle and convert hydrofluorocarbon refrigerants into safe products. Much of the experimental work will take place in Shiflett’s lab at KU, where the NSF award will support equipment and materials costs, as well as support the training and education of a new generation of engineering students. “About $590,000 is coming to KU, and the rest is split between the other three universities,” Shiflett said. “Doing these experiments requires chemicals, analytical instruments and specialized research equipment. This grant will support eight graduate students, and two of those are at KU. Each institution is going to be supporting graduate students, and the grant will also support several undergraduate researchers.
