CO2 Emissions Turned To Stone In Icelandic Experiment

Science / Tech
Iceland Hellisheidi Geothermal powerplant CO2

Humans produce an incredible amount of carbon dioxide, which, when left unchecked, makes its way into our atmosphere. Icelandic researchers have discovered a way to more quickly and easily capture some of these carbon emissions and store them in a manner where they will not damage our ecosystem. The Carbfix project has found that under the right conditions, CO2 emissions can simply be turned to stone.

The testing has required that the CO2 first be diluted in water, preventing it from escaping into the atmosphere. That mixture was injected into the layer of basalt under Iceland’s Hellisheidi power plant at a depth of 400-500 meters. The researchers observed using tracer chemicals that 95% of the carbon dioxide gas had turned to stone in a period of just two years. This type of result was a huge surprise, as researches figured the change would take quite a lot longer.

The benefit of this carbon capture and storage (CCS) system is not only in the speed, which was honestly just a welcome surprise, but also in the cost. Other CCS methods that have been attempted tend to keep the CO2 in a gaseous state in sedimentary rocks, such as in depleted oil reservoirs. Unlike basalt, these sedimentary rocks do not have the minerals required to turn the CO2 into stone, and since it’s stored as a gas, it needs to be monitored to ensure there are no leaks. Before it can even be pumped into the underground reservoir, the CO2 must also be separated from the other chemicals and gasses in the emissions. All of those factors add up to make that type of CCS both expensive, and impractical.

One drawback to this new method is that for ever tonne of CO2 to be buried, 25 tonnes of water are required. The upside to this is that researchers say that seawater can absolutely be used, so that will eliminate that issue for coastal sites at least.

The Icelandic project is currently ramping up in order to bury 10,000 tonnes of CO2 and hydrogen sulfide per year. The carbon dioxide will simply turn to stone while the hydrogen sulfide will turn into other minerals.

The Icelandic project is one of several ongoing experiments with CCS. The results so far are promising, but it will be a matter of time to see if this method can keep up with the amount of CO2 produced.

  Source: The Guardian
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