@article{28d6ac6a771a426e8200720147d58fef,
title = "Application of noble gas tracers to identify the retention mechanisms of CO2 migrated from a deep reservoir into shallow groundwater",
abstract = "Carbon Capture and Storage (CCS) is a valuable climate-mitigation technology, which offers the potential to cost-effectively reduce the emissions associated with the burning of fossil fuels. However, there is a potential risk of a small portion of the stored CO2 unintentionally migrating from a storage site to a shallow groundwater aquifer which is the final retaining zone for any migrated CO2 before it escapes to the atmosphere. Hence, it is imperative to identify the physical retention mechanisms of CO2 within a shallow aquifer. In this study 1.70 × 102 kg of CO2 and noble gas tracers (He, Ar and Kr) were continuously injected into a groundwater aquifer over 28 days with the aim of identifying the mechanisms and amount of CO2 retention. Among the tracers, Kr was found to be the earliest indicator of CO2 migration. The other tracers – He and Ar – arrived later and exhibited diluted signals. The diluted signals were attributed to degassing of the plume mass (1.6 % of CO2) during the early stages of CO2 migration. Diffusion accelerated the dilution of the lighter elements at the plume boundaries. Consequently, the clear relation of the noble gases with the CO2 proved that degassing and mixing primarily control the mass retention of CO2 in shallow groundwater, and the relative importance of these processes varies along the evolving path of migrating CO2.",
keywords = "Artificial tracer, CCS, CO leakage, Geochemical Monitoring, Monitoring, Noble gas tracing",
author = "Ju, {Yeo Jin} and Gilfillan, {Stuart M.V.} and Lee, {Seong Sun} and Dugin Kaown and Doshik Hahm and Sanghoon Lee and Park, {In Woo} and Ha, {Seung Wook} and Keyhong Park and Do, {Hyun Kwon} and Yun, {Seong Taek} and Lee, {Kang Kun}",
note = "Funding Information: This research was supported by a Korea Environmental Industry & Technology Institute (KEITI) grant entitled “R&D Project on Environmental Management of Geologic CO2 Storage” (Project Number: 2018001810002), by a Korea Polar Research Institute grant (PE20140) and by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF-2018R1C1B6007390). We thank all the members of the K-COSEM team and, appreciate Intae Kim and Minjung Kim for their efforts and support on noble gas analysis. Also, we appreciate the help of Dr. Stan E. Beaubien in interpreting the noble gas data. Finally, the authors would like to thank two anonymous reviewers for their detailed comments and observations which greatly improved the present paper. Funding Information: This research was supported by a Korea Environmental Industry & Technology Institute (KEITI) grant entitled “R&D Project on Environmental Management of Geologic CO2 Storage” (Project Number: 2018001810002), by a Korea Polar Research Institute grant ( PE20140 ) and by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF- 2018R1C1B6007390 ). We thank all the members of the K-COSEM team and, appreciate Intae Kim and Minjung Kim for their efforts and support on noble gas analysis. Also, we appreciate the help of Dr. Stan E. Beaubien in interpreting the noble gas data. Finally, the authors would like to thank two anonymous reviewers for their detailed comments and observations which greatly improved the present paper. Publisher Copyright: {\textcopyright} 2020 Elsevier Ltd",
year = "2020",
month = jun,
doi = "10.1016/j.ijggc.2020.103041",
language = "English",
volume = "97",
journal = "International Journal of Greenhouse Gas Control",
issn = "1750-5836",
publisher = "Elsevier",
}