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Mechanisms for mechanical trapping of geologically sequestered carbon dioxide.

ABSTRACT: Carbon dioxide (CO₂) sequestration in subsurface reservoirs is important for limiting atmospheric CO₂ concentrations. However, a complete physical picture able to predict the structure developing within the porous medium is lacking. We investigate theoretically reactive transport in the long-time evolution of carbon in the brine-rock environment. As CO₂ is injected into a brine-rock environment, a carbonate-rich region is created amid brine. Within the carbonate-rich region minerals dissolve and migrate from regions of high-to-low concentration, along with other dissolved carbonate species. This causes mineral precipitation at the interface between the two regions. We argue that precipitation in a small layer reduces diffusivity, and eventually causes mechanical trapping of the CO₂. Consequently, only a small fraction of the CO₂ is converted to solid mineral; the remainder either dissolves in water or is trapped in its original form. We also study the case of a pure CO₂ bubble surrounded by brine and suggest a mechanism that may lead to a carbonate-encrusted bubble owing to structural diffusion.

SUBMITTER: Cohen Y

PROVIDER: S-EPMC4353055 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature

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Mechanisms for mechanical trapping of geologically sequestered carbon dioxide.

Cohen Yossi Y Rothman Daniel H DH

Proceedings. Mathematical, physical, and engineering sciences 20150301 2175

Carbon dioxide (CO2) sequestration in subsurface reservoirs is important for limiting atmospheric CO2 concentrations. However, a complete physical picture able to predict the structure developing within the porous medium is lacking. We investigate theoretically reactive transport in the long-time evolution of carbon in the brine-rock environment. As CO2 is injected into a brine-rock environment, a carbonate-rich region is created amid brine. Within the carbonate- ...[more]

PMID: 25792961

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Mechanisms for mechanical trapping of geologically sequestered carbon dioxide.

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Mechanisms for mechanical trapping of geologically sequestered carbon dioxide.

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