CO2 storage safe in the long term, study shows

A technology developed to store carbon dioxide emissions deep underground is likely to be effective for thousands of years, research shows.

Researchers assessed the method, in which liquefied CO2 is injected into microscopic pores in rocks, by compiling a worldwide database using information from naturally occurring gas accumulations and from industry.

Their findings lend confidence to the potential widespread use of the emerging technology.

Storage models

The study by the Universities of Aberdeen and Edinburgh – partner institutes of Scottish Carbon Capture & Storage – included details obtained from engineered gas storage, decades of borehole injection, and laboratory experiments.

Computer simulations were used to combine all these factors and model the storage of carbon dioxide for 10,000 years into the future.

Previous research in this area had not fully accounted for the natural trapping of microscopic bubbles of carbon dioxide in rock, nor the dissolving of carbon dioxide into salty water present in the rock.

Emission reductions

The United Nations’ Paris Agreement has committed the world to limiting climate warming to well below 2C compared with pre-industrial levels.

This requires huge reductions in the amount of carbon dioxide released to the atmosphere from industry, electricity generation, heating and transport.

Capturing these emissions and ensuring that carbon dioxide can be safely trapped underground could play a key role in protecting the atmosphere.

The study, supported by the Natural Environment Research Council, was published in Nature Communications.

Our computer simulations, based on good regulatory practices such as those used currently in the North Sea, retained more than 90 per cent of injected carbon dioxide after 10,000 years, in 95 per cent of cases.

Dr Stephanie FludeSchool of GeoSciences

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