- Distribution and Behavior of Soil CO2 in Pohang area: Baseline Survey and Preliminary Interpretation in a Candidate Geological CO2 Storage Site
- Park, Jinyoung;Sung, Ki-Sung;Yu, Soonyoung;Chae, Gitak;Lee, Sein;Yum, Byoung-Woo;Park, Kwon Gyu;Kim, Jeong-Chan;
- Korea Institute of Geoscience and Mineral Resources (KIGAM);Korea Institute of Geoscience and Mineral Resources (KIGAM);Research Institute for Social Criticality, Pusan National University;Korea Institute of Geoscience and Mineral Resources (KIGAM);Korea Institute of Geoscience and Mineral Resources (KIGAM);Korea Institute of Geoscience and Mineral Resources (KIGAM);Korea Institute of Geoscience and Mineral Resources (KIGAM);Korea Institute of Geoscience and Mineral Resources (KIGAM);
- 포항 지역 토양 CO2의 분포 및 거동 특성 연구: CO2 지중저장 부지 자연 배경 조사 및 예비 해석
- 박진영;성기성;유순영;채기탁;이세인;염병우;박권규;김정찬;
- 한국지질자원연구원;한국지질자원연구원;부산대학교 사회급변현상연구소;한국지질자원연구원;한국지질자원연구원;한국지질자원연구원;한국지질자원연구원;한국지질자원연구원;
Abstract
Distribution and behavior of baseline soil CO2 were investigated in a candidate geologic CO2 storage site in Pohang, with measuring CO2 concentrations and carbon isotopes in the vadose zone as well as CO2 fluxes and concentrations through ground surface. This investigation aimed to assess the baseline CO2 levels and to build the CO2 monitoring system before injecting CO2. The gas in the vadose zone was collected using a peristaltic pump from the depth of 60 cm below ground surface, and stored at gas bags. Then the gas components (CO2, O2, N2, CH4) and δ13CCO2 were analyzed using GC and CRDS (cavity ringdown spectroscopy) respectively in laboratory. CO2 fluxes and CO2 concentrations through ground surface were measured using Li-COR in field. In result, the median of the CO2 concentrations in the vadose zone was about 3,000 ppm, and the δ13CCO2 were in the wide range between −36.9‰ and −10.6‰. The results imply that the fate of CO2 in the vadose zone was affected by soil property and vegetations. CO2 in sandy or loamy soils originated from the respiration of microorganisms and the decomposition of C3 plants. In gravel areas, the CO2 concentrations decreased while the δ13CCO2 increased because of the mixing with the atmospheric gas. In addition, the relation between O2 and CO2, N2, and the relation between N2/O2 and CO2 implied that the gases in the vadose zone dissolved in the infiltrating precipitation or the soil moisture. The median CO2 flux through ground surface was 2.9 g/m2/d which is lower than the reported soil CO2 fluxes in areas with temperate climates. CO2 fluxes measured in sandy and loamy soil areas were higher (median 5.2 g/m2/d) than those in gravel areas (2.6 g/m2/d). The relationships between CO2 fluxes and concentrations suggested that the transport of CO2 from the vadose zone to ground surface was dominated by diffusion in the study area. In gravel areas, the mixing with atmospheric gases was significant. Based on this study result, a soil monitoring procedure has been established for a candidate geologic CO2 storage site. Also, this study result provides ideas for innovating soil monitoring technologies.
Keywords: Geologic CO2 storage;Soil CO2 monitoring;
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