|Stuart Gilfillan and Thomas Ogilvie sampling in Saskatchewan|
Researchers from Scottish Carbon Capture & Storage (SCCS) have developed a way to measure tiny traces of inactive natural gases, known as noble gases, found in CO₂. These noble gases vary depending on whether the CO₂ is from just below ground or deep below, enabling scientists to fingerprint a sample and pinpoint its source.
The technique, developed by scientists at the University of Edinburgh, has been conclusively used to investigate an alleged leak from CO₂ injected underground at a farm in Saskatchewan, Canada. The test showed that high levels of CO₂ recorded on the farm arose from nearby wetlands and were not leaking from a CCS site at the nearby Weyburn Oil Field.
While studies have shown that small amounts of CO₂ seepage carry no significant threat to human health, the new test will allow scientists and storage site developers to reassure residents that CO₂ storage sites are secure.
The technique will be useful in countries, such as Canada and the USA, where onshore CO₂ storage is already underway. In the UK, which has ample offshore CO₂ storage, scientists are researching how this test can be combined with other offshore monitoring methods.
Dr Stuart Gilfillan of the University of Edinburgh’s School of GeoSciences, who led the study, said:
Carbon capture and storage is an essential means to curb emissions of greenhouse gases, which is needed to limit global warming to 2°C, as internationally agreed recently in Paris. Securely storing captured CO₂ is critical to its success and our method of identifying any leaks should give assurance to local communities. Our work provides a simple way to easily and unambiguously spot leaks from future storage sites, using the fingerprint of noble gases that the CO₂ picks up during storage.
The study has been published in the International Journal of Greenhouse Gas Control and was funded by the Natural Environment Research Council and SCCS. Read the full paper
|Stuart Gilfillan and Jerry Sherk undertake more sampling at one of the test sites|