Adsorption of humid air in compacted montmorillonite: A Monte Carlo simulation study

Upgrading Wood Gas Using Bentonite Clay: A Multiscale Modeling and Simulation Study

“…Bentonite is a clay mineral available locally in South Africa (there is a commercially exploited deposit near Heidelberg in the Western Cape province) that consists chiefly of crystalline montmorillonite . Therefore, compacted montmorillonite was used as a proxy for bentonite in this study, similar to recent work on the use of bentonite as an adsorbent for humid air . Bentonite has wide use in the food and beverage industry as a purification medium, as drilling mud, as a foundry binder, and as a protein adsorbent, among other uses .…”

“…Both COMPASS and PCFF are described as consistent force fields although PCFF is older, and recent work employing COMPASS showed good agreement with experimental data in terms of hydrogen sulfide adsorption relative to nitrogen in another silicate material (cement hydrate). Moreover, the COMPASS force field has already been used to successfully model adsorption of humid air in montmorillonite . Therefore, COMPASS was deemed appropriate for this study.…”

“…13 Therefore, compacted montmorillonite was used as a proxy for bentonite in this study, similar to recent work on the use of bentonite as an adsorbent for humid air. 14 Bentonite has wide use in the food and beverage industry as a purification medium, as drilling mud, as a foundry binder, and as a protein adsorbent, among other uses. 15 Bentonite has also been studied in the last decade for applications as diverse as separating oil from water, 16 the development of clay/rubber nanocomposites, 17 and in radioactive waste disposal.…”

“…26 The van der Waals interactions are described using the 9-6 Lennard-Jones potential 27 coupled with the Waldman−Hagler 28 combining rules in the COMPASS force field. The simulation cell consisted of six montmorillonite unit cells (constructed by arranging 3 × 2 × 1 unit cells together), similar to previous work 14 that showed this to be the minimum system size necessary to avoid periodicity errors 29 when simulating adsorption in montmorillonite. Alternatives to the COMPASS force field that are also fully atomistic include the PCFF 30 and DREIDING 31 force fields.…”

Adsorption of H2S from Hydrocarbon Gas Using Doped Bentonite: A Molecular Simulation Study

“…Bentonite is a clay mineral consisting predominantly of montmorillonite, which was employed as a proxy for bentonite in this study, 33 similar to recent studies that examined its use for wood gas upgrading 34 and humidity reduction. 35 A crystalline montmorillonite structure from the previous work concerning montmorillonite containing the Li + cation 36 was used as a basis for bentonite in this work (the postheat treatment structure was employed in this study to approximate a realistically modified adsorbent). In order to obtain bentonite with K + and Na + in this work, the Li + in the initial lattice was substituted.…”