New analytical approach brings greater confidence to plastic upcycling research
How do scientists and engineers know how well a plastic upcycling technology works? The answer matters, because new and better processes will move from the laboratory to full scale commercial adoption only if researchers can accurately measure how well they work. Companies, policymakers, and investors need reliable ways to know if a process converts waste into valuable products efficiently enough to be economically competitive.
Until recently, it could be hard to tell precisely. Many of the chemical processes that break down the long strands of polymers that make up plastic result in a complex number of products—many different gases, some liquids, and some that remain solids. Without precise information about the products and byproducts, it can be difficult to evaluate catalysts and compare different technologies.
Researchers at the Institute for the Cooperative Upcycling of Plastics (iCOUP) have developed a detailed analytical system for tracking exactly what happens when common plastics such as polyethylene and polypropylene are chemically broken down into smaller molecules.
“We found that, as with most chemical transformations, changing the catalysts or conditions changes the products that are formed," said Aaron Sadow, director of iCOUP and Ames National Laboratory scientist. “Unfortunately, it can be difficult to fully compare experiments with different product compositions without knowing exactly what was produced. That’s why we spent time over multiple years developing and refining the techniques needed to accurately quantify upcycling products.”
The research team published a step-by-step protocol that combines multiple laboratory techniques so researchers can account for nearly all of the carbon from the original plastic. The method tracks everything from hydrogen gas and methane to heavy waxes and leftover polymer material. It allows scientists to calculate not only how much plastic was converted, but also how many chemical bonds were broken and how efficiently a catalyst performed.
The researchers’ results demonstrate that, when used together, these measurements can achieve carbon balances greater than 95%, giving researchers far more confidence in their results.
Scientists around the world are working to develop catalysts, reactors, and chemical processes that will convert waste plastics into marketable products like fuels, lubricants, recycled plastics, and chemical feedstocks. But without a standardized way to evaluate performance, it’s difficult to compare one technology to another. This protocol addresses one of the least visible but most important barriers to solving the global plastic waste problem: knowing whether proposed solutions actually work.
By providing a more complete picture of what happens during plastic upcycling reactions, the protocol could help researchers identify the most promising approaches for future development and commercialization. The methodology can also reveal previously overlooked products that may have economic value, creating new opportunities to improve the efficiency and economic feasibility of plastic upcycling processes.
As researchers continue searching for better ways to transform plastic waste into useful materials, tools that accurately measure performance may prove just as important as the catalysts and technologies themselves.
The research, “Comprehensive quantitative analysis of polyolefin hydrogenolysis toward plastic waste management”, was published in a recent edition of Nature Protocols.
The work was supported by the Institute for Cooperative Upcycling of Plastics (iCOUP), an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Basic Energy Sciences, and led by Ames National Laboratory.
Ames National Laboratory is a U.S. Department of Energy Office of Science National Laboratory operated by Iowa State University. Ames Laboratory creates innovative materials, technologies, and energy solutions. We use our expertise, unique capabilities, and interdisciplinary collaborations to solve global problems.
Ames Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit https://energy.gov/science.