TY - JOUR
T1 - Effect of gas impurity on the convective dissolution of CO2 in porous media
AU - Mahmoodpour, Saeed
AU - Amooie, Mohammad Amin
AU - Rostami, Behzad
AU - Bahrami, Flora
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/5/15
Y1 - 2020/5/15
N2 - Growing needs for energy and the essential role of fossil fuels in energy market require attempts such as carbon dioxide (CO2) sequestration in saline aquifers to stabilize and mitigate atmospheric carbon concentrations. The possibility of co-injection of impurities along with CO2 allows for the direct disposal of flue gas and hence a significant reduction in the cost of CO2 sequestration projects by eliminating the separation process. In this study, the results of series of novel experiments in a high-pressure visual porous cell are reported, which allow for visually and quantitatively examining the dynamics of convective dissolution in brine-saturated porous media in the presence of an overlying impure free gas phase with conditions that reflect more closely the subsurface conditions. We find cases with 10% (respectively, 20%) N2 impurity show higher (respectively, lower) dissolution flux and greater (respectively, smaller) pressure drop at early time as compared to those with pure CO2. To shed light on this non-trivial behavior, image analysis is performed and hydrodynamic dispersion is revealed as the root to this behavior. Robust scaling relations for the obtained dispersion coefficients and transition time to the shut-down dissolution regime are reported based on dimensionless numbers. Additionally, multiphysics numerical simulations are performed and coupled with the captured dispersion quantities. Our findings elucidate how the presence of impurity in gas stream affects the overall efficiency of CO2 convective mixing, and how its essence can be leveraged in practice while improving the numerical models.
AB - Growing needs for energy and the essential role of fossil fuels in energy market require attempts such as carbon dioxide (CO2) sequestration in saline aquifers to stabilize and mitigate atmospheric carbon concentrations. The possibility of co-injection of impurities along with CO2 allows for the direct disposal of flue gas and hence a significant reduction in the cost of CO2 sequestration projects by eliminating the separation process. In this study, the results of series of novel experiments in a high-pressure visual porous cell are reported, which allow for visually and quantitatively examining the dynamics of convective dissolution in brine-saturated porous media in the presence of an overlying impure free gas phase with conditions that reflect more closely the subsurface conditions. We find cases with 10% (respectively, 20%) N2 impurity show higher (respectively, lower) dissolution flux and greater (respectively, smaller) pressure drop at early time as compared to those with pure CO2. To shed light on this non-trivial behavior, image analysis is performed and hydrodynamic dispersion is revealed as the root to this behavior. Robust scaling relations for the obtained dispersion coefficients and transition time to the shut-down dissolution regime are reported based on dimensionless numbers. Additionally, multiphysics numerical simulations are performed and coupled with the captured dispersion quantities. Our findings elucidate how the presence of impurity in gas stream affects the overall efficiency of CO2 convective mixing, and how its essence can be leveraged in practice while improving the numerical models.
KW - Carbon sequestration
KW - Convection
KW - Dispersion
KW - Dissolution
KW - Impurity
KW - Saline aquifers
UR - http://www.scopus.com/inward/record.url?scp=85082185075&partnerID=8YFLogxK
U2 - 10.1016/j.energy.2020.117397
DO - 10.1016/j.energy.2020.117397
M3 - Article
AN - SCOPUS:85082185075
SN - 0360-5442
VL - 199
JO - Energy
JF - Energy
M1 - 117397
ER -