A new trial scheme in Iceland is claiming to be the world’s first to combine direct air capture (DAC) of CO2 with permanent geological storage.
The CarbFix2 project is a collaboration between Swiss startup Climeworks and Reykjavik Energy. Located just outside the Icelandic capital at Hellisheidi, it is centred around one of the world’s largest geothermal power plants.
The first stage in the process sees CO2 captured from ambient air using Climeworks’ DAC technology, which involves a patented filter. According to the company, the filter is made of porous granulates modified with amines and works by binding the CO2 with the moisture in the air.
Next, low-grade heat from the geothermal plant is used to release pure C02, which is then sent more than 700m underground. Here, it reacts with the basaltic bedrock and forms solid minerals, creating a permanent storage solution. The trial will test the technology under the specific weather conditions at the location in the South West of Iceland, and shed light on DAC’s viability for wider capture solutions.
Basalt core containing carbonates (Credit: Sandra O Snaebjornsdottir)
“We have developed CarbFix at a unique location here in Iceland and proved that we can permanently turn this greenhouse gas into rock,” said Edda Sif Aradóttir, CarbFix project leader at Reykjavik Energy.
“By imitating natural processes this happens in less than two years. By integrating the Climeworks and CarbFix technologies we create a solution that is deployable where we have basalt but independent of the location of emissions. This is important to scale up the CarbFix approach on a global level.”
Climeworks, which was spun out from STEM university ETH Zurich, has set itself the goal of capturing one per cent of global CO2 emissions by the year 2025. Earlier this year it opened the world’s first commercial DAC plant at Hinwil, Switzerland. Although that facility only has capacity to capture 900 tons of CO2 annually – and Carbfix will sequester only 50 tons per year – Climeworks believes the technology can scale successfully.
“The potential of scaling-up our technology in combination with CO2 storage is enormous,” said Christoph Gebald, founder and CEO of Climeworks.
“Not only here in Iceland but also in numerous other regions which have similar rock formations. Our plan is to offer carbon removal to individuals, corporates and organisations as a means to reverse their non-avoidable carbon emissions.”