Climeworks joins project to trap carbon dioxide in rocks

The Swiss company Climeworks has launched a pilot plant in Hellisheidi, Iceland, that can capture carbon dioxide directly from the air to be pumped into underground rock formations, effectively locking the greenhouse gas away for good.

Installed on the grounds of a geothermal power plant, the new direct air capture plant joins a project called CarbFix2, led by Reykjavik Energy and funded partly by the European Union’s Horizon 2020 research and innovation program.

CarbFix2 is an extension of the decade-old CarbFix project, which has injected 18,000 metric tons of CO₂ dissolved in large amounts of water deep into the surrounding basalt-rich rock. The dissolved CO₂ reacts with basalt to form solid carbonate mineral, a transformation that occurs relatively quickly, according to a 2016 study by CarbFix researchers.

Previously, the CarbFix project sequestered waste CO₂ from the neighboring geothermal power plant, which releases about 3% of the CO₂ emitted by a fossil-fuel plant, according to CarbFix project leader Edda Sif Aradóttir. In the new partnership, the Climeworks facility will capture CO₂ straight from the air. It will rely on the geothermal power plant for low-grade heat to release the captured CO₂ from its absorbent filters.

In May, Climeworks opened the first commercial direct air capture plant in Hinwil, Switzerland, where captured CO₂ is fed to an adjoining greenhouse to fertilize vegetables. A nearby waste incineration plant provides the necessary heat.

Coupling Climeworks’ direct air capture technology with carbon sequestration is exciting because it could potentially produce negative emissions, meaning the permanent removal of CO₂ from the atmosphere, says Giana Amador, managing director of the nonprofit Center for Carbon Removal. Climate experts agree that along with drastic emissions reductions, negative emissions are necessary to meet international goals to mitigate climate change, she says.

Other CarbFix2 project partners include the University of Iceland, the French National Center for Scientific Research, and the Spanish environmental consulting company Amphos 21.