Modification of free-energy density functional theory approach for prediction of high-pressure mixture adsorption  

作　　者：LIU ShuYan YANG XiaoNing YANG Zhen 

机构地区：[1]School of Mechanical and Power Engineering, Nanjing University of Technology, Nanjing 210009, China [2]College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China

出　　处：《Chinese Science Bulletin》2008年第9期1358-1364,共7页

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 20276028 and 20476044)

摘　　要：A modified non-local free energy density functional theory (NDFT) model, with the consideration of the nonadditivity term of solid-fluid and fluid-fluid interactions and finite pore wall thickness (≈2 layers), was developed to model the confined fluid mixtures in slit pore. This improved NDFT approach, com- bining with the pore size distribution (PSD) analysis of adsorbent material can be applied to predicting the adsorption equilibria of high-pressure gas mixtures on activated carbon. Compared with the con- ventional NDFT method, this new approach partly improves the correlation performance of adsorption equilibrium for pure species and increases the reliability of the PSD analysis. For the mixtures, CH4/N2 and CO2/N2, a relatively improved performance has been observed for the adsorption equilibrium pre- diction of the mixtures under high-pressure conditions, especially for the weakly adsorbed species.A modified non-local free energy density functional theory （NDFT） model, with the consideration of the nonadditivity term of solid-fluid and fluid-fluid interactions and finite pore wall thickness （≈2 layers）, was developed to model the confined fluid mixtures in slit pore. This improved NDFT approach, combining with the pore size distribution （PSD） analysis of adsorbent material can be applied to predicting the adsorption equilibria of high-pressure gas mixtures on activated carbon. Compared with the conventional NDFT method, this new approach partly improves the correlation performance of adsorption equilibrium for pure species and increases the reliability of the PSD analysis. For the mixtures, CH4/N2 and CO2/N2, a relatively improved performance has been observed for the adsorption equilibrium prediction of the mixtures under high-pressure conditions, especially for the weakly adsorbed species.

关 键 词：高压吸附作用 碳 裂缝 气孔 自由能密度 

分 类 号：O4[理学—物理]