Multiphase Monte Carlo and Molecular Dynamics Simulations of Water and CO₂ Intercalation in Montmorillonite and Beidellite

Abstract

Multiphase Gibbs ensemble Monte Carlo simulations were carried out to compute the free energy of swelling for Na-montmorillonite and Na-beidellite interacting with CO 2 and H 2 O at pressure and temperature conditions relevant for geological storage aquifers. The calculated swelling free energy curves show stable monolayer and bilayer configurations of the interlayer species for Namontmorillonite, while only the monolayer structure is found to be stable for Na-beidellite. The calculations show that CO 2 is intercalated into hydrated clay phases at concentrations greatly exceeding its solubility in bulk water. This suggests that expandable clay minerals are good candidates for storing carbon dioxide in interlayer regions. For Na-beidellite the CO 2 molecule distribution is mainly controlled by the position of the isomorphic substitutions, while for Namontmorillonite the presence of the hydrated sodium ions plays an important role in establishing the CO 2 distribution.

Molecular Dynamics Simulations of Carbon Dioxide, Methane, and Their Mixture in Montmorillonite Clay Hydrates

“…2). 19,20,22,57,[66][67][68] Previous simulations reported the ratios of diffusion coefficients of CO 2 to water for 20 well-defined layered structures, similar to the behavior of pure hydration states or binary mixture (water/CO 2 and water/CH 4 ) profiles described in the previous section.…”

“…19,20,22,57,[66][67][68] An important finding is that the diffusion of CO 2 in the interlayers of Na-montmorillonite, show that similar effects of water on both carbon dioxide and methane, increase with increasing water content, at constant loadings of CO 2 and CH 4 in the interlayers of Namontmorillonite. Our results could be useful, such as for designing separation devices, CO 2 storage, and also for better understanding the behavior of fluids in nanoporous rocks (e.g., shales).…”

“…50,51,66 To understand the molecular structure of adsorbed layers of the different species in the interlayers and to identify the preferential adsorption sites on the montmorillonite substrate, we calculated in-plane (xy) density distributions. All these calculations were performed for each molecule found within either the first closest adsorption layer (monolayer) near to the clay surface or away from it (see, e.g., Fig.…”

A molecular dynamics investigation into the adsorption behavior inside {001} kaolinite and {1014} calcite nano-scale channels: the case with confined hydrocarbon liquid, acid gases, and water

“…An example of this kind is the study the interaction of carbon dioxide and clay minerals, a matter of potential usage for underground carbon sequestration purposes (Chen et al 2015a, b, c;Javanbakht et al 2015;Makaremi et al 2015;Tenney and Cygan 2014). Another example of the kind is the study of interactions between mineral surfaces (representative of reservoir rocks) and mixture of hydrocarbon/water/acid gases (representing typical reservoir fluids), to put petroleum production industry in target (Chun et al 2015;Fazelabdolabadi and Alizadeh-Mojarad 2016;Underwood et al 2015;Wu et al 2012) or analysis of mobilization and recovery of fluids/asphaltene from nanopores using MD Youssef et al 2015;Stukan et al 2012).…”

Pressure-driven supercritical CO2transport through a silica nanochannel

“…6(a), showing the formation of several structuring layers for scCO 2 molecules, which is consistent with previous reports. 18,24,37,60 For H ¼ 7.25Å, the two symmetrical density peaks indicate that scCO 2 form two primary adsorption layers due to partial superimposition of the attractive potentials from two surfaces.…”