First facility grabs CO₂ from the air and stores it underground

Enlarge / It sucks air in and separates carbon dioxide out. (credit: Climeworks – Zev Starr-Tambor)

In a press conference presentation Wednesday, Reykjavik Energy’s Edda Aradóttir described the company’s new project as “turning the CO₂ troll to stone.” If deployed at scale, the technology behind this could make a big difference in charting a better climate future—capturing CO₂ gas and locking it away underground before it can add to the growing greenhouse effect.

Last year, the people behind the project, which is termed “CarbFix,” published a paper outlining the remarkable success they’d had in pilot operation. CO₂ captured from a geothermal power plant (the hot geothermal water comes up with some volcanic CO₂ as well) was injected back down into the Icelandic basalt, where it reacted with the rock and turned into carbonate minerals. This is the ultimate fate for CO₂ injected underground everywhere, but it usually takes hundreds to thousands of years. In the basalt, the CO₂ had mineralized in a matter of years, making this a particularly attractive way to deal with the CO₂ troll.

Meanwhile, a young company in Switzerland called Climeworks was opening its first plant to capture CO₂—not from relatively concentrated smokestack effluent, but from ambient air. CO₂ is much more dilute in ambient air, comprising about 0.04 percent of atmospheric gas currently. So capturing it economically is much more difficult. For that reason, efforts to develop this particular technology have been slow in coming.