Captured CO2 can be securely stored underground, study shows

June 13 (UPI) -- Carbon dioxide can be safely and securely stored underground for thousands of years, according to a new study out of the University of Aberdeen in Scotland.

Carbon capture technologies have proven their ability to pull CO2 from the air, and they're now becoming a reality, with some facilities already operating in Europe. But questions about how the captured carbon will be stored have remained.

Scientists at Aberdeen analyzed several carbon storage methods used by energy companies and tested by engineers over the last several decades. Using the scientific literature, researchers developed a model to simulate the long-term performance of each storage method.

Their calculations showed underground storage can ensure CO2 remains out of the atmosphere for at least 10,000 years.

"We selected the model inputs to be conservative but realistic," researchers Stephanie Flude said in a news release. "Importantly, our computer simulations, based on good-regulation practices, such as those used currently in the North Sea, retained more than 90 percent of the injected carbon dioxide after 10,000 years in 95 percent of the cases. The most probable outcome being at least 98 percent retention."

To store CO2 underground, the gas is converted in liquified gas and injected deep beneath the surface at high pressure. The new research -- published this week in the journal Nature Communications -- suggests the CO2 naturally becomes trapped in microscopic bubbles found inside rocks. The carbon dioxide can also become dissolved by salty water already trapped in rocks.

"The security of carbon dioxide storage is an understandable concern for people, communities and governments," said researcher Juan Alcalde. "Our work shows that the storage of carbon dioxide necessary to help address climate change can be secure for many thousands of years."

New research has shown that climate scientists and policy makers may have put too much emphasis on containing temperature increases and not enough on curbing increases in atmospheric CO2. As such, carbon capture technologies could be essential to minimizing the consequences of climate change.