Geological, geochemical and social-scientific assessment of basaltic aquifers as potential storage sites for CO2

Abstract

known engineering problems would prevent large-scale implementation of CO 2 storage in such aquifers. The greatest remaining need is to ensure storage security. During CO 2 sequestration in deep aquifers, the captured CO 2 is typically injected into a formation at depths of more than 800 m, where pressure and temperature are above the critical point of CO 2 (31.1°C, 7.38 MPa) (Bachu, 2002). Because supercritical fluids are highly mobile, however, the injected CO 2 might flow in the aquifer and CO 2 might leak to the surface. Storage security therefore depends on restricting CO 2 flow in the storage aquifer.Injected CO 2 can be trapped by either physical or geochemical trapping mechanisms. Structural/ stratigraphic, gravitational, and residual gas trapping are physical mechanisms. In structural/stratigraphic trapping injected CO 2 is stored as a gas, liquid, or supercritical August 24, 2012; Accepted March 9, 2013) Basaltic aquifers have the potential to provide secure option for CO 2 sequestration. Because basaltic rocks are widely distributed around the world, their capacity for storage of anthropogenic CO 2 emissions is enormous. In addition, geochemical trapping of CO 2 injected into basaltic aquifers occurs quickly, because basaltic rocks contain many cations that react with CO 2 to form stable carbonate minerals. Two types of large-scale basaltic aquifers may be suitable for sequestering huge amounts of anthropogenic CO 2 : continental flood basalt aquifers and deep-sea basalt aquifers. Here, we assess the potential of these two CO 2 sequestration options from geological, geochemical and social-scientific perspectives.From a geological and geochemical viewpoint, both continental flood basalt and deep-sea basalt aquifers have excellent CO 2 storage potential. In deep-sea basalt aquifers, however, storage of injected CO 2 may be more secure than in continental flood basalt aquifers, because leakage of CO 2 to the atmosphere is minimized by geological, geochemical and physical barriers associated with the deep-sea environment. In addition, from a social-scientific point of view, several current CO 2 injection projects in continental flood basalts have encountered problems due to groundwater depletion, and large-scale implementation of CO 2 storage in continental flood basalt aquifers might cause contamination of freshwater resources needed for domestic and agricultural use. In striking contrast to continental flood basalts, deep-sea basalts can be used for CO 2 storage without encountering critical problems, because deep-sea basalt aquifers have no economic value. We conclude, therefore, that deep-sea basalt aquifers are a better option for CO 2 storage than continental flood basalt aquifers.

Long‐Term Reaction Characteristics of CO2–Water–Rock Interaction: Insight into the Potential Groundwater Contamination Risk from Underground CO2 Storage

“…Volcanic rock aquifers exist all over the world and may be promising candidates for CO 2 storage (Takaya et al , ). However, some also serve as important water resources for surrounding regions (Reilly et al , ; Rodell et al , ).…”

A Comprehensive Review of Geological CO2 Sequestration in Basalt Formations

“…Snaebjörnsdóttir et al, 2020). 특히, 현무암은 다른 암 석 대비 CO 2 지중 광물화 잠재용량이 높고 (Xiong et al, 2017), 해양 지층과 대륙 지층 모두에서 광범위하게 분포 하고 있으며 (Snaebjörnsdóttir et al, 2017;Takaya et al, 2013b) (Cilek, 2009;Cox, 2013;Gill and Fitton, 2022). 형성된 화성암은 관입암 또는 심성암 및 화산암으로 분 류되는데 (Gill and Fitton, 2022), 이 중 현무암은 흑색 또는 암회색의 고철질/초고철질 화산암으로서, 화성암 중 해양 지각에 가장 풍부한 암석이다.…”

Unique Environmental Conditions Required for Dawsonite Formation: Implications from Dawsonite Synthesis Experiments under Alkaline Conditions

“…This uncertainty in the formation conditions of dawsonite has been fueling a considerable controversy on the security of geologic carbon sequestration for decades. , In geologic carbon sequestration, injected CO 2 dissolves and ionizes in the reservoir water (solubility trapping) and reacts with surrounding host rocks to form carbonate minerals, such as CaCO 3 and MgCO 3 (mineral trapping). This series of chemical reactions, called geochemical trapping, transforms injected CO 2 into a more stable phase (carbonate minerals) and is, therefore, recognized as an important factor, ensuring the security of geologic carbon sequestration. − In this sense, CO 2 –water–rock interactions under CO 2 reservoir conditions have been investigated extensively with laboratory experiments, − field tests, − and numerical simulations − to evaluate the potential of geochemical trapping. Although many numerical simulation studies have predicted the formation of dawsonite in CO 2 -charged reservoirs, − dawsonite formation is rarely observed in laboratory experiments under CO 2 reservoir conditions.…”