CO2 storage test can distinguish carbon from coal, gas and biomass

A new method of carbon storage and monitoring, which can determine the origin of a CO₂ sample by analysing its chemical fingerprint, is to be used for a leading research project.

Designed to monitor and ensure the safe storage of industrial greenhouse gas emissions, the new method will aid the development of carbon capture and storage technology, which stores the carbon dioxide from power stations and industrial sites securely underground.

University of Edinburgh researchers developed the test by showing that the chemical fingerprint of CO₂ captured from power stations and industrial sites remains recognisable after it’s injected underground. The result is stored industrial CO₂ can be distinguished from other sources of the gas, such as groundwater or natural emissions from plants and bacteria.

The same study, published in the International Journal of Greenhouse Gas Control, reveals how the chemical signature of CO₂ emissions varies with the source of emissions, such as coal, gas or biomass.

Study leader Dr Stephanie Flude, of the University of Edinburgh’s School of GeoSciences, said in a statement: "The chemical fingerprint of captured CO₂ varies depending on the capture technology used. This will be useful for tracking CO₂ injected into storage sites and means that in most cases there is no need to add expensive artificial tracers."

The new method was verified by studying the chemical fingerprint of CO₂ from chemical storage sites in Australia and Canada. After sampling gas before and after its injection into underground storage, it was found that the fingerprints remained identifiable. It was also found that changes to the fingerprints during storage gave insights into behaviour of the CO­₂ underground.

"Our study paves the way for inexpensive monitoring of CO2 underground for safe, secure storage,” said Dr Stuart Gilfillan, study co-ordinator, also of the School of GeoSciences. “We look forward to working with Carbon Management Canada in applying our findings at the new Canadian CCS test site, which will demonstrate the exciting methods we have developed.”