Spatio-Temporal Soil CO2 Flux after Artificial CO2 Release in Korea.

Abstract Carbon capture and storage (CCS) is a technical process to capture CO₂ from industrial and energy-based sources, transfer and sequestrate impressed CO₂ in geological formations, oceans, or mineral carbonates. However, potential CO₂ leakage may exist and cause environmental problems. This study was conducted to evaluate the monitoring and detection system by analyzing the spatial and temporal variation of soil CO₂ flux after artificial CO₂ release in Korea. The unsaturated Environmental Impact Evaluation Test Facility was built in Eumsung, Korea in 2014. The artificial CO₂ release experiment was carried out from 26 to 30 October 2015. Soil CO₂ flux at the surface was measured at 0m, 1.5m, 2.5m, and 15m from the CO₂ releasing well using an automated soil CO₂ flux system, and soil CO₂ concentrations at 15cm, 30cm, and 60cm depths were obtained at every 0m, 1.5m, 2.5m, 5m, and 10m distances from the well using a portable gas analyzer. Soil CO₂ leakage signal was shown as 38.4% at 60cm depth at 0m from the well after 2 days. Soil CO₂ was leaked more widely, and detected up to 5m away from the well at all depths after 5 days. Soil CO₂ flux was measured up to 89% at 60cm depth at 0m from the well, followed by 30cm depth (82.5%) and 15cm depth (55.4%) at the same distance. On the other hand, soil CO₂ leakage at the surface was found at 0m distance from the well after 4 days, and increased over 9 days even though the artificial CO₂ release stopped. The spatial and temporal information considering the CO₂ flux after artificial CO₂ release can be obtained from the current study, which is valuable for demonstrating the monitoring system to detect CO₂ leakage.

Acknowledgement This study is the part of the project entitled “Korea CO₂ Storage Environment Management Research Center (K-COSEM) – Project No. 2014001810002” funded by the Ministry of Environment (MOE), Republic of Korea.

Keywords: Carbon capture and storage, Detection system, Geochemical monitoring technique, Leakage, Soil CO₂ flux