A radical breakthrough has occurred in project CarbFix in Iceland after scientists have discovered a way to turn carbon dioxide gas into stone.
At the Hellisheidi geothermal power plant in Iceland, scientists pumped a carbon dioxide and water mixture 540 metres underground into basalt rock. The acidic mixture causes calcium magnesium in the rock to be dissolved and form limestone. According to Juerg Matter, the lead author of a study detailing the experiment, this process permanently and naturally traps the carbon dioxide. Dr. Matter added: 'basically carbon dioxide is converted into stone.''
The results of the experiment have been greeted with much praise after scientists were able to mineralise 95% of the 220 tonnes of carbon dioxide they injected into the rock and convert it to limestone in under two years.
Potential issues for the widespread use of this technique include whether there is enough underground space to store the carbon. According to Dr Matter, Iceland is not alone in its large quantities of basalt rock, this type of rock is present on every continent and the sea floor. However consideration would still have to be given to storing the carbon before it is processed and the costs involved in piping the carbon dioxide to viable locations. Unfortunately political co-operation may prove to be a challenge in this as pipelines may need to cross borders.
A further potential issue is that currently tests have only been carried out using clean geothermal energy carbon dioxide emissions. Emissions which come from coal-fired power plants for example will be much dirtier. With these kind of emissions it is unknown whether the chemical conversion process will work, or if it will work at the same speed as with cleaner emissions.
Despite these challenges, the results remain impressive. While they may not signal the end of climate change, they do demonstrate advancements in carbon capture and storage that could play a huge part in overall greenhouse gas emission reduction across the world.
The project in Iceland has now been increased in scale and is on course to store 10,000 tonnes of CO2 this year alone. Testing of this process has also started in the United States in the Columbia River Basalts, an extensive area of the rock in Washington and Oregon.
