CO2 fingerprinting prevents leaks from storage sites

The technique, developed by researchers from the University of Edinburgh, relies on what the researchers describe as the natural fingerprint of CO2, which differs based on the source, as well as the capture technology used.

For example, CO2 produced by burning gas in a power station would be different from that produced by burning coal, biomass or oil and these would be different from the CO2 produced naturally by plants or animals.

These differences are present without any additional modifications.

"Defining these natural fingerprints in captured CO2 will simplify the monitoring of geological CO2 storage sites,” said Stephanie Flude from the University of Edinburgh's School of GeoSciences, who led the study published in the latest issue of the journal Environmental Science and Technology.

“This method is inexpensive as it removes the need to add additional expensive artificial tracers to the CO2 being stored."

Leaks of greenhouse gas from sites storing carbon dioxide in future would undermine the efficiency of the climate change-battling technology. Being able to effectively monitor and thus fix and prevent those leaks is a major challenge the researchers are trying to solve. To be able to tell with certainty whether there is a leak the researchers need to be able to tell the difference between the CO2 stored and that naturally occurring.

"There has been a pressing need to identify a means to distinguish CO2 to be stored from that already in the subsurface to help CCS [carbon capture and storage] deployment,” explained Stuart Gilfillan, the study co-ordinator.

“Our study shows that natural fingerprints in the captured CO2 are unique and depend on the capture technologies being used. This paves the way for natural fingerprints to be used to track the CO2 once it is injected underground for storage."

The study, described as the first of its kind, was supported by the Engineering and Physical Sciences Research Council.

Widespread deployment of CCS technologies, which enable emissions from power plants and other industrial facilities to be captured and permanently stored underground, could help reduce global emissions by approximately 15 per cent by 2050, according to the International Energy Agency.

However, the UK government cancelled funding for two pioneering CCS projects last November. The decision was described as a major setback for CCS development in the UK.