Students Build a Cleaner, Greener Smokestack

Newswise — Students at Michigan Technological University have designed and built a smokestack that can capture carbon dioxide and turn it into a useful product. Their 11-foot bench-model smokestack packed with glass beads percolates away in their lab, which is under the supervision of Komar Kawatra, chair of the chemical engineering department. Near the top, a proprietary liquid dribbles down. From below, carbon dioxide bubbles up. By the time the gas reaches the top, fully half of the CO2 has been gobbled up by the liquid.

The process not only captures carbon, it binds it in a solid form, making an undisclosed product that can be used as a construction material. The liquid itself can be recovered and used again. The group has applied for a patent and hopes to build a pilot plant in cooperation with an industry partner, Carbontec Energy Corporation.

Other scrubbers remove up to 90 percent of the carbon dioxide from a smokestack, Kawatra notes, but the liquid must be processed to strip away the carbon dioxide, which is generally compressed and stored. “This is a very expensive technique, which is probably why we do not see it commonly employed in industry,” says PhD student Brett Spigarelli of Iron Mountain, Mich., a member of the research team.

The group is working to make the scrubber remove even more carbon dioxide. In the meantime, it offers businesses a significant benefit.

"Industry has a problem with CO2 capture and sequestration because it is an added cost with no direct benefit to them,” Kawatra said. “But, if it is possible for industry to both capture CO2 and produce a product from the CO2 that they can sell, then they will be much more interested. Our goal is therefore to not only capture the CO2 at the lowest possible cost, but also to manufacture useful, marketable products.”