Early atmospheric detection of carbon dioxide from carbon capture and storage sites

摘要

The early atmospheric detection of carbon dioxide (CO_2) leaks from carbon capture and storage (CCS) sites is important both to inform remediation efforts and to build and maintain public support for CCS in mitigating greenhouse gas emissions. A gas analysis system was developed to assess the origin of plumes of air enriched in CO_2, as to whether CO_2 is from a CCS site or from the oxidation of carbon compounds. The system measured CO_2 and O_2 concentrations for different plume samples relative to background air and calculated the gas differential concentration ratio (GDCR = -ΔO_2/ ΔCO_2). The experimental results were in good agreement with theoretical calculations that placed GDCR values for a CO_2 leak at 0.21, compared with GDCR values of 1-1.8 for the combustion of carbon compounds. Although some combustion plume samples deviated in GDCR from theoretical, the very low GDCR values associated with plumes from CO_2 leaks provided confidence that this technology holds promise in providing a tool for the early detection of CO_2 leaks from CCS sites. Implications: This work contributes to the development of a cost-effective technology for the early detection of leaks from sites where CO_2 has been injected into the subsurface to enhance oil recovery or to permanently store the gas as a strategy for mitigating climate change. Such technology will be important in building public confidence regarding the safety and security of carbon capture and storage sites.