Iceland Turns CO2 Into Solid Rock

A consortium of scientists have perfected a new way to store carbon, but its very Iceland specific.
Jessica Miley

The amount of CO2 in the atmosphere hit an all-time record high since the evolution of humans this week. Higher than normal levels of CO2 in the atmosphere is one of the leading causes of climate change as it blocks the Earth's natural cooling ability. CO2 levels are increasing due to the burning of fossil fuels and other human actions such as deforestation.


If we are to avoid the catastrophe of the earth warming by 2 degrees radical action must be taken which includes slashing the amount of CO2 produced. Slowing climate change is also only possible by the introduction of technologies that can remove CO2 from the atmosphere.

Mimicking Nature

Iceland is leading the way in one of these methods and after two years of experimentation, their system seems to be working. CarbFix is a collaboration between researchers and engineers from utility company Reykjavik Energy, the University of Iceland, France's National Centre for Scientific Research (CNRS) and Columbia University in the United States.

The technology developed by the group mimics a natural process, but instead of taking thousands of years can see the results in just a handful. The process works by injecting CO2 into porous basalt rock where it mineralizes, capturing it forever. "With this method we have actually changed the time scale dramatically," says geologist Sandra Osk Snaebjornsdottir.

Geothermal Power Plant Acts as Lab

The research team has spent the last two years using the Hellisheidi geothermal power plant, as their own laboratory. The plant, which is one of the biggest in the world is located on the Hengill volcano in southwestern Iceland. It sits on a layer of basalt rock formed from cooled lava, the plant has access to an almost unlimited amount of water which it pumps up from under the volcano to run six turbines providing electricity and heat to the capital, Reykjavik, about 30 km away.

The CO2 from this process is captured from the steam, liquified into condensate, then dissolved in large amounts of water. This CO2 heavy water is then piped to an area several kilometers away. The water is then blasted into the basalt rock 1,000 m below where it fills the rock's cavities and begins the solidification process,. A chemical reaction occurs when the gas comes in makes contact with the calcium, magnesium and iron in the basalt.

Pilot program a big success

"Almost all of the injected CO2 was mineralised within two years in our pilot injection," Snaebjornsdottir says. The CarbFix project reduces the power plant's carbon dioxide emissions by a third, which amounts to 12,000 tonnes of CO2 captured and stored at a cost of about $25 a tonne.

But Iceland is still far from being a model country in the fight against climate change. Under the Paris climate agreement, Iceland has agreed to slash its greenhouse gas emissions by 40% by 2030. Yet its emissions rose by 2.2% from 2016 to 2017, and have risen by 85% since 1990, according to a report by Iceland's Environment Agency.

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