Effect of water on methane adsorption on the kaolinite (0 0 1) surface based on molecular simulations

Zhang, Bin; Kang, Jianting; Kang, Tianhe

doi:10.1016/j.apsusc.2017.12.239

Cited by 99 publications

(53 citation statements)

References 54 publications

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“…To study the kaolinite-water-CH 4 systems, the initial state of all models used here are the final output of Monte-Carlo simulations computed in our preceding work (Zhang et al 2018a) in which the temperature was fixed at 293.15 K and pore size was 0.72 nm. The number of water molecules was 0, 9, 18, 27, 36, and 45, corresponding to the water contents of 0, 1, 2, 3, 4, and 5 wt%, respectively.…”

Section: Molecular Dynamics Simulation Details 21 Modelsmentioning

confidence: 99%

“…The Dreiding force field (Mayo et al 1990;Fafard et al 2017;Zhou et al 2017) was selected in all simulations and can be utilized to study the physical and diffusion properties of kaolinite structures which has been confirmed in our previous works (Zhang et al 2018a, b). The electrostatic and van der Waals interactions between CH 4 and kaolinite were simulated by Ewald method with a cut-off value of 0.8 nm (Rutkai and Kristóf 2008).…”

Section: Implementation Of Simulationmentioning

confidence: 99%

“…where f is the bulk gas fugacity, C is the sorption concentration, and o ln f o ln c is the thermodynamic factor. Figure 6a showed the curve of lnf (logarithm of the fugacity), which was obtained based on the Peng-Robinson equation of state (Zhang et al 2018a) versus lnC (logarithm of the sorption concentration) calculated according to the study of Zhang et al (Zhang et al 2018a, b). In Eq.…”

Section: Transport Diffusion Coefficientmentioning

confidence: 99%

“…The effect of pre-adsorbed water on diffusion capacity can be further analyzed by calculating the interaction between kaolinite, H 2 O and CH 4 . The calculation of the interaction energy has been shown in detail in our previous work (Zhang et al 2018a, b).The interaction energy between the CH 4 and kaolinite, between the CH 4 and water, between the CH 4 and CH 4 , and between the kaolinite and water were analyzed at 293.15 K and 5 MPa, as shown in Fig. 9.…”

Section: Interaction Energymentioning

confidence: 99%

See 3 more Smart Citations

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Zhang

Kang

et al. 2019

Int J Coal Sci Technol

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Understanding the interaction of CH 4 with kaolinite is significant for researchers in the fields of coalbed CH 4 and shale gas. The diffusion behaviors of CH 4 in kaolinite with water contents ranging from 0 to 5 wt% have been analyzed by molecular dynamics simulations. The results of the simulations indicate that CH 4 molecules can jump between adjacent holes in the kaolinite matrix. CH 4 diffusion coefficient was very low (3.28 9 10 -9 m 2 /s) and increased linearly with the increasing of water content. As the water content decreased, the value of radial distribution function first peak between CH 4 and oxygen was larger, meaning that with lower water content, the interaction energy between CH 4 and oxygen in kaolinite is stronger. The interaction between CH 4 and water is linearly positively correlated with water content, in contrast, the interaction energy between kaolinite and water as well as between kaolinite and CH 4 decreased linearly with increasing water content. On the other hand, the diffusion of CH 4 molecules adsorbed on the surfaces also can be accelerated by the fast diffusion of water molecules in the middle micropore of the kaolinite.

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Section: Molecular Dynamics Simulation Details 21 Modelsmentioning

confidence: 99%

Section: Implementation Of Simulationmentioning

confidence: 99%

Section: Transport Diffusion Coefficientmentioning

confidence: 99%

Section: Interaction Energymentioning

confidence: 99%

See 2 more Smart Citations

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Zhang

Kang

et al. 2019

Int J Coal Sci Technol

Self Cite

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“…Previous studies have included clay minerals, activated carbon, zeolites, alumina and so on [12][13][14][15][16][17][18]. For kaolinite, one of the most abundant components in clay minerals [19,20], many previous researches have been conducted about its surface absorption of the CO 2 , methane, ammonia ions and heavy metals [21][22][23][24][25][26][27][28], but few studies have dealt with the adsorption mechanism of ammonia gas on kaolinite.…”

Section: Introductionmentioning

confidence: 99%

Molecular Modeling of Ammonia Gas Adsorption onto the Kaolinite Surface with DFT Study

Cheng

Qiao

et al. 2020

Minerals

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With high porosity and being one of the most abundant clay minerals, dried kaolinite may be an excellent adsorbent to remove ammonia gas (NH3). Here, the plane wave pseudopotential method based on density functional theory (DFT) was used to explore the mechanism of ammonia gas adsorption on the dried kaolinite, the Mulliken electric charge, and the partial density of states of atoms of the NH3/kaolinite (001) system. NH3 adsorption on kaolinite can happen in three different type adsorption positions: “top”, “bridge” and “hollow”. The “hollow” position is enclosed by two "upright" hydroxyl groups perpendicular to the (001) surface of kaolinite and a "lying" hydroxyl group parallel to the surface. At this position, the adsorption is the most stable and has the highest adsorption energy. The nitrogen atom of the NH3 molecule bonds with the hydrogen atom in the "upright" hydroxyl group on the (001) surface and its hydrogen atom forms HN…O hydrogen bond with oxygen atom in the "lying" hydroxyl group, which leads to the NH3 stably adsorbed on kaolinite (001) surface. A small part of electrons transfer between NH3 molecules and kaolinite creates weakly electrostatic adsorption between them.

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Molecular simulation to discover rheological properties and soil‐binding ability of PHPA polymer on montmorillonite surface

Yang

Adhikari

2020

Surface & Interface Analysis

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Synthetic polymer fluids are increasingly being applied to support excavations in deep foundations. As these fluids are molecularly engineered, their underlying microstructure interaction with in situ soils significantly affect excavation stability and soil dispersion. However, little molecular‐scale research has been done on the rheological behavior of partially hydrolyzed polyacrylamides (PHPA) polymer fluids on the clay surface. Molecular models of the clay–polymer systems are constructed using PHPA on montmorillonite (MMT) clay surface. Initial rheological properties and soil‐binding ability at different shear rates, temperatures, and polymer concentrations are first studied using molecular dynamics (MD) simulations. It is found that the functional groups of PHPA can interact with the MMT surface and form a viscous film under the atomic interaction of hydrogen bonds, water bridges, and electrostatic attraction. The shear stress, σ increases with the shear rate and follows the power‐law model. And the viscosity, η decreases as the shear rate increases, which is consistent with the experimental trend. However, the σ and η decrease with the increase of temperature. And the action mode of PHPA concentration has been identified from the MD perspective. This work provides insight into the molecular mechanism for PHPA's rheology on the clay surface and their interaction.

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Effect of water on methane adsorption on the kaolinite (0 0 1) surface based on molecular simulations

Cited by 99 publications

References 54 publications

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Molecular Modeling of Ammonia Gas Adsorption onto the Kaolinite Surface with DFT Study

Molecular simulation to discover rheological properties and soil‐binding ability of PHPA polymer on montmorillonite surface

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Effect of water on methane adsorption on the kaolinite (0 0 1) surface based on molecular simulations

Cited by 99 publications

References 54 publications

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Molecular dynamics simulations of CH4 diffusion in kaolinite: influence of water content

Molecular Modeling of Ammonia Gas Adsorption onto the Kaolinite Surface with DFT Study

Molecular simulation to discover rheological properties and soil‐binding ability of PHPA polymer on montmorillonite surface

Contact Info

Product

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About

Effect of water on methane adsorption on the kaolinite (0 0 1) surface based on molecular simulations