CO2 scrubber turns carbon emissions into building materials

The CO2 collecting smokestack with Michigan Tech chemical engineering PhD student Brett Spigarelli (Photo: George Olszewski)

Students at Michigan Technological University have designed and constructed their own mini-smokestack to showcase a new method for scrubbing carbon dioxide from emissions. The approach is similar to SkyMine technology, but instead of producing sodium bicarbonate as a byproduct, it turns captured carbon into a solid material that could have applications as a construction material.

The students are being discreet with some of the detail due to patents pending but have demonstrated a percolating 11 foot bench model. The smokestack is packed with glass beads, where a proprietary liquid drips down from the top as carbon dioxide bubbles up from the bottom. As the gas floats to the top, the CO2 is soaked up by the liquid, halving the emissions. The captured carbon reformed into a solid may then be sold and used as an construction material – the exact nature of which hasn't been revealed – with the remaining liquid recycled into the process once more.

The team is refining the smokestack design to remove even more carbon dioxide to give industry more benefit and the next step is to realize plans for a pilot plant to be built in collaboration with Carbontec Energy Corporation.

Other scrubbers can remove up to 90% of the CO2 from a smokestack, but the liquid used must be processed to strip away the carbon dioxide, which then needs to be 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, a member of the research team.

"Industry has a problem with CO2 capture and sequestration because it is an added cost with no direct benefit to them," Komar Kawatra, Chair of the Chemical Engineering Department at Michigan Tech 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."