Plant that turns CO2 into stone

Swiss company Climeworks is partnering with a geothermal power plant in Iceland to create a power plant that converts CO2 into minerals.

Geothermal power plant in Iceland. Photo: Arni Saeberg.

An international team of scientists has been working on a way to turn captured CO2 into a hard mineral for the past few years. The project, called CarbFix, involves soaking CO2 in water and injecting it 700 meters underground. When it comes into contact with basalt, the CO2 solution quickly forms a carbon-containing mineral, New Atlas reported yesterday.

Previously, researchers thought the mineralization process could take anywhere from hundreds to thousands of years, but scientists at the CarbFix project were surprised to find that CO2 turned into a hard mineral in less than two years.

Climeworks' plant in Zurich captures carbon from the air. Video: YouTube.

"Our results show that about 95-98% of the CO2 was mineralized in less than two years, which is surprisingly fast," said Dr Juerg Matter, who led the study.

Climeworks has been a pioneer in the use of the new DAC system over the past few years. The technology allows CO2 to be collected from ambient air into a patented filter. The CO2 is then purified and sold to businesses that need CO2 for commercial purposes. Climeworks’ first plant in Zurich ships the captured CO2 to a nearby greenhouse.

Carbon sequestration, in which CO2 is captured and stored in underground reservoirs, has become a controversial topic in recent years. A 2015 study from the Massachusetts Institute of Technology found that previous sequestration processes were ineffective. While CO2 can be captured, there is no large-scale method for safely removing it, raising concerns that the sequestered CO2 could leak back into the atmosphere.

Combining Climeworks DAC technology with CarbFix mineralization allows for a system that is not only carbon neutral, but also carbon leak-free.

According to VNE