in recent years have proposed many alternative to address climate change induced by human activities. One of the possible technical solutions to reduce the concentration in the atmosphere greenhouse gases associated with climate change is carbon capture and storage (CCS stands English), of which there are various proposals and pilot projects in ten countries.
Schematically it would be to capture carbon dioxide (CO2) produced for example in power plants that burn fuel and then inject this greenhouse gas in deep subsurface layers.
So far, most techniques CCS have had little success due to problems such as high cost, the difficulty of capturing large amounts of greenhouse gases or the risk that the gas injected under earth back into the atmosphere through cracks or leaks.
An encouraging result
a team of 19 researchers from seven different nationalities presented this week through a article published in the journal Science the encouraging results of a pilot CCS carried out during the past five years in Iceland test. “This study demonstrates for the first time” the effectiveness of a process of permanently removing CO2 as carbonate minerals shortly after the injection of this gas in basaltic rocks, the authors explain in the article presenting their results.
Specifically, the data indicate that “more than 95% of the injected CO2 at the site CarbFix in Iceland was mineralized in the form of carbonate in less than two years,” a period much lower than calculated up now for CCS processes in other types of rocks.
The study led by Juerg Matter, University of Southampton (UK) describes specific work by Icelandic plant CarbFix where carbon dioxide was injected into wells spanning basaltic lava to a depth between 400 and 800 meters. Using a set of indicators, the authors determined that most of the injected carbon dioxide was mineralized in less than 2 years.
According to the authors say, since carbonates are stable, this approach is not so exposed to the risk of leakage of carbon dioxide produced, which means it could be significantly reduced level monitoring storage sites basalt. Because this technique depends mainly on the water and porous basalt rocks, which are found in large quantities in the continental margins of many parts of the world, the authors also suggest that it will be possible to perform the experiment on a larger scale.
A very special power plant
Carbon dioxide injected into the CarbFix plant comes from the geothermal plant Hellisheidi, which pumps heated water from volcanic rocks and so far emitted into the atmosphere about 40,000 tons of CO2 per year. Since 2012, the CarbFix project has injected a part of this greenhouse gas basalt rocks of volcanic origin, at a depth of between 400 and 800 meters.
The Guardian
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