A research team led by Professor Minkee Choi of the Department of Chemical and Biomolecular Engineering succeeded in developing an amine-based carbon dioxide adsorbent that is significantly more resistant to oxidation than previously existing adsorbents. The research results were published online in the February 20 issue of Nature Communications.
Carbon dioxide is the main cause of global warming. For this reason, research on the development of carbon dioxide adsorbents is being carried out across the globe, in order to capture the gas and to reduce its presence in the atmosphere. Among the different types of adsorbents, solid yet porous adsorbents encapsulating a polymeric amine have garnered the attention of researchers.
However, existing amine-based solid adsorbents suffer from stability problems, despite their excellent carbon dioxide adsorption. Because of the oxidative decomposition of the amine due to oxygen in the exhaust gas of thermal power plants, the adsorbents’ performance deteriorates and therefore cannot be repetitively used.
Professor Choi’s research team discovered that very small amounts of metal impurities, like iron and copper, were present in commercial polymeric amines. These impurities acted as catalysts, accelerating the oxidative decomposition of the amines.
By introducing a small amount of chelator, a catalyst poison that inhibits the activity of the discovered impurities, the team was able to dramatically decrease the oxidation of the adsorbents. The developed adsorbent retained over 92 percent of its adsorption performance, which is 50 times more than that of previously existing ones.
According to the researchers, due to its superb carbon dioxide absorption and desorption characteristics and its oxidation stability, the developed adsorbent is significantly more practical than conventional solid adsorbents.
“This study has great significance since it solved the problem of the oxidative decomposition of the solid carbon dioxide adsorbent enough for it to be commercialized,” said PhD student Woo Sung Choi, the first author.
Professor Choi said, “The carbon dioxide adsorbent has entered the initial stage of commercialization,” and “Because the research history is short, there are many parts to improve. We will continue the development of the adsorbent so it can become the world’s best carbon dioxide adsorbent.”