Selective combustion offers an energy-efficient alternative to remove contaminants from industrial processes

Researchers at the University of Minnesota Twin City have discovered a new method that allows the catalyst to be used to selectively burn a single molecule with a mixture of hydrocarbons, a compound made of hydrogen and carbon atoms.

This new method can help remove contaminants and improve the efficiency of industrial processes, from fuel and drug production to fertilizers and plastics.

This study has been published in Science.

By using bismuth oxide catalysts, a material that speeds up chemical reactions, researchers can selectively burn one molecule in a combustible mixture. Researchers have shown that small amounts of acetylene can be effectively burned into a mixture with ethylene. Removing acetylene is an important process to prevent poisoning of polymerization catalysts. This is essential for the production of polyethylene plastics, a market that exceeds 120 million tonnes per year.

“No one else has shown that in a mixture with others, one hydrocarbon that is present in low concentration can be burned,” says Professor in the Department of Chemical Engineering and Materials Science, and the paper’s professor. said Aditya Bhan, the lead investigator.

Traditionally, the combustion process is used to generate heat to burn all hydrocarbon fuel mixtures at high temperatures. Using catalysts allowed researchers to tackle the challenge of burning one molecule rather than another. Bismuth oxide catalysts are unique because they provide their own oxygen during combustion, rather than using oxygen from external sources.

“We managed to remove oxygen from the catalyst and return it multiple times. The catalyst changes slightly, but its reactivity is not affected. Operating in this chemical loop mode will avoid any intense concerns. ” Candidate and first author for the Minnesota PhD in Chemical Engineering.

Traditionally, eliminating small amounts of contaminants is very challenging and energy-intensive, but this new method could offer a more energy-efficient alternative.

“We want to selectively do this process. Removing acetylene and other trace hydrocarbon contaminants in this way could be more energy efficient,” he said, a professor in the Department of Chemical Engineering and Materials Science. said Matthew Newlock, senior co-author of the paper. “We just want to be able to enter the gas mixture to remove some molecules without touching the rest of the molecules.”

Researchers said that the long-term impact could be high as catalysts are used in almost everything that modern society touches, from fuel and drug production to fertilizers and plastics. Understanding how molecules burn and not burn on the surface of the catalyst is valuable to make fuel and plastic production more efficient.

“If you can understand how catalysts work at the molecular atomic level, you can adapt to specific reactions,” says a prominent scientist at Stanford University’s SLAC National Accelerator Institute and co-author of the study. Simon Bare said. . “This helps us understand how catalysts that produce the fuels and chemicals needed for modern life respond to the environment.”

In addition to Byrne, Jacob, Newlock and Bear, the University of Minnesota Chemical Engineering and Materials Science team includes graduate students Rishi Raj and Professor Hui Nuguen and Andre Mukhoyan, who are also involved in Javier, a characterization facility at the University of Minnesota. Included along with Garcia Barriocanard. . Additional team members include Jiyun Hong, Jorge E. Perez-Aguilar and Adam S. Hoffman of SLAC National Accelerator Institute at Stanford University.