Molecular dynamics simulations were performed to gain fundamental molecular insights on the concentration-dependent adsorption and gas transport properties of the components in a CH4/CO2 gaseous mixture in single- and double-layered nanoporous graphene (NPG) and graphene oxide (NPGO) separation platforms. While these platforms are promising for a variety of separation applications, much about the relevant gas separation mechanisms in these systems is still unexplored. Based on the gas adsorption results in this work, at least two layers of CO2 are formed on the gas side of both NPG and NPGO, while no adsorption is observed for pure CH4 on the single-layered NPG. In contrast, increasing the CH4 concentration in the CH4/CO2 mixture leads to an enhancement of the CH4 adsorption on both separation platforms. The through-the-pore diffusion coefficients of both CO2 and CH4 increase with an increase in the CH4 concentration for all NPG and NPGO systems. The permeance of CO2 is smaller than that of CH4, suggesting the NPG and NPGO platforms are more suitable as CO2 adsorbents or membranes for the CH4/CO2 (rather than the CO2/CH4) separation. The highest observed selectivities for the CH4/CO2 separation in the NPG and NPGO platforms are about 5 and 6, respectively.

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An experimental investigation has been carried out in order to analyse the drop size distributions of liquid-liquid dispersion in a single stage mixer settler extractor. In this paper, the effects of the impeller speed and the holdup on mean drops size, D 32 , have been investigated. D 32 was decreased with an increase in the impeller speed. Furthermore, D 32 was increased with an increase in the holdup. In addition, a new and modified correlation was established based on these results. The average absolute relative deviation is 3.36%.Uneétude expérimentale aété effectuée pour analyser la répartition de la taille des gouttes pour la dispersion liquide-liquide dans un extracteurdécanteur-mélangeuràétage unique. Dans cet article, onétudie les effets de la vitesse d'agitation et la retenue d'une goutte de taille moyenne, D32. D32 diminuait avec l'augmentation de la vitesse d'agitation. De plus, D32 augmentait avec l'augmentation de la retenue. Par ailleurs, une corrélation nouvelle et modifiée aété mise en place en se basant sur ces résultats. L'écart relatif absolu moyen est de 3,36%.

The effects of holdup on Sauter mean drop diameter, D 32 , and dispersed phase mass transfer coefficient have been studied in the spray and packed extraction columns. For both columns, two well-defined regions for the dependence of D 32 on holdup were observed. D 32 increased and decreased with an increase in holdup at low and high levels of holdup, respectively. Changes in dispersed phase mass transfer coefficient against holdup were shown to be similar to D 32 for both columns. Moreover, empirical correlations have been derived to predict D 32 and dispersed phase mass transfer coefficient for both columns. It has been shown that the derived correlations are in a good agreement with the experimental data.

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