In Iceland, CO2 sucked from the air is turned to rock

Good News Notes:

At the foot of an Icelandic volcano, a newly-opened plant is sucking carbon dioxide from the air and turning it to rock, locking away the main culprit behind global warming.

Orca, based on the Icelandic word for “energy,” does its cutting-edge work at the Hellisheidi geothermal power plant in southwest Iceland.

It is the world’s largest plant using the direct air capture technology (DAC) increasingly lighting up the imagination as the world struggles to avert catastrophic global warming.

Yet DAC is the least developed of the carbon removal technologies promoted as the key to compensating for the slow switch away from fossil fuels.

Climeworks, a Swiss start-up that has just built the plant around 30 kilometres from the capital Reykjavik in a tie-up with Icelandic companies, is not deterred.

“You have to learn to walk before you can run,” said Julie Gosalvez, in charge of marketing for the company.

Her firm works with Iceland’s Carbfix, which has pioneered underground carbon storage, and ON Power, a local geothermal electricity provider.

The enterprise uses Carbfix’s method that mimics, in accelerated format, a natural process that can take hundreds of thousands of years.

By pulling CO2 from ambient air, the plant is different from more traditional types of carbon capture and storage (CCS) projects at highly-polluting industrial smokestacks.

The giant steel structure resting on cement slabs and linked to a maze of pipes is powered by the nearby geothermal power plant.

The facility is made of eight containers similar to those used in maritime transport, stacked up in pairs.

Fans in front of the collector draw in ambient air and release it, largely purified of CO2, through ventilators at the back.

Project manager Lukas Kaufmann said “very selective filter material inside our collector containers” catch carbon dioxide.

– Turned to rock –

“As soon as the filter is full, we close it off, and then we heat it up to around 100 degrees Celsius” to separate the pure gas, Kaufmann added.

Once free of impurities after treatment in the adjoining process hall, the carbon dioxide is then piped underground a distance of three kilometres (1.8 miles) to an area where grey, igloo-shaped domes dot a lunar-like landscape.

Dissolved in fresh water, the gas is then injected under high pressure into the basalt rock between 800 and 2,000 metres underground.

The solution fills the rock’s cavities and the solidification process begins — a chemical reaction turning it to calcified white crystals that occurs when the gas comes in contact with the calcium, magnesium and iron in the basalt.

It takes up to two years for the CO2 to petrify.

Carbfix insists the method is the safest and most stable to stock carbon for now.

The carbon dioxide would only be re-released into the air if the rock were to heat up to very high temperatures, as in a volcanic eruption, Didier Dalmazzone, head of the chemistry laboratory at French engineering school ENSTA Paris, told AFP….”

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