Carbon capture and storage takes a leap forward thanks to basalt

The carbon capture and storage equipment used to inject 1,000 tons of CO2 into the underground basalt formation - image courtesy of BSCSP

US researchers have taken another step closer to developing a scaleable option to capture and store carbon dioxide (CO2) using a new technique that involves injecting liquefied gas into ancient lava flows.

Researchers at the Big Sky Carbon Sequestration Partnership (BSCSP), at the Wallula Basalt Pilot Project in Washington State, have turned liquefied carbon dioxide into solid rock by injecting the gas into basalt formations. This type of carbon capture and storage could help manage the amount of carbon in the atmosphere and in turn help to mitigate global warming, one of the most serious threats facing humanity in the 21st century.

One of the keys which makes the study’s results so important is that the ‘trapped’ gas can not escape back to the atmosphere, even if the underground repository in which it is housed is somehow compromised due to an environmental disaster.

The study at the Washington State site has found that carbon dioxide that was captured and injected into basalt, which is commonly formed by lava flow, will turn into solid rock in just two years. The findings suggest that CO2 could be converted into stable carbonate minerals using this method and therefore trapping it in rock for good.

The pivotal carbon capture and storage study undertaken at the Wallula Basalt Pilot Project by researchers from the Pacific Northwest National Laboratory and found that the carbon dioxide solidified into a mineral called ankerite over a period of just two years. This finding contradicted the previous general view that mineralisation in carbon capture and storage projects takes hundreds or even thousands of years. The research was published in the Environmental Science and Technology journal.

This injection process could be a groundbreaking method to tackle carbon capture and storage and help mitigate global warming. The UN recently warning governments that more needs to be done to address climate change, with the UN Environmental Program stating in November 2016 that annual emissions will need to be cut by an additional 12-14 billion metric tons by 2030 to keep global warming from surpassing 2°C this century.

Carbon capture technique locks away 1,000 tons of CO2

The injecting process at the Wallula site began on July 17, 2013 when researchers commenced the injection of nearly 1,000 tons of CO2 into the basalt formation.

By August 11, 2013, 977 tons of was successfully injected into the basalt reservoir, with the one-month procedure having been monitored by scientists looking for important changes in the subsurface environment and indications of abnormal behaviour.

Running concurrently with the Wallula Basalt Pilot Project, researchers at the CarbFix project in Iceland pumped CO2 into volcanic rock near a power plant.

The research sped up the natural process where the basalts react with the gas to form carbonate minerals which make up limestone, with the research team amazed at how fast the gas turned into a solid – just two years.

The CarbFix project demonstrated that over 95% of captured and injected at Hellisheidi geothermal Power Plant was mineralized within two years.

The study is an integral one as it is the first demonstration of its kind in the US, with its results set to provide scientists with crucial information on the potential for basalt formations to provide long-term storage of CO2 emissions.

The potential for this technique has been made even more exciting due to the vast presence of flood basalts throughout the world, indicating that there could be many sites for this type of CO2 storage.