Molecular Simulations of Adsorption and Diffusion Behaviors of Benzene Molecules in NaY Zeolite

• Published in: Chinese journal of chemical engineering Vol. 17; no. 4; pp. 618 - 624
• Main Author: 张舟 刘辉 朱吉钦 陈标华 田辉平 贺振富
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2009
• Subjects: Adsorption; Benzene; Computer simulation; Diffusion; Diffusivity; Grand Canonical Monte Carlo; kinetic Monte Carlo; MD模拟; Monte Carlo methods; NaY; NaY沸石; Tungsten; Zeolites; 分子动力学; 分子模拟; 吸附系统; 扩散行为; 苯分子; 蒙特卡罗; Grand Canonical Monte Carlo; adsorption; diffusion; benzene; NaY; kinetic Monte Carlo
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60253-0

In the article the Grand Canonical Monte Carlo （GCMC）, molecular dynamics（MD）, and kinetic Monte Carlo （KMC） simulations with particular focus on ascertaining the loading dependence of benzene diffusion in the zeolite were performed. First, a realistic representation of the structure of the sorbate-sorbent system was obtained based on GCMC simulation. The simulation clearly shows the characteristics of the adsorption sites of the benzene-NaY system, from which two kinds of preferably adsorbing sites for benzene molecules, called SⅡ and W sites, are identified. The structure thus obtained was then used as a basis for KMC and MD simulations. A compara-tive study by introducing and comparing two different mechanisms underlying jump diffusion in the zeolite of in-terest shows that the.MS diffusivity values predicted by the KMC and MD methods are fairly close to each other,leading to the conclusion that for benzene diffusion in NaY, the SⅡ→W→SⅡ jumps of benzene molecules are dominated,while the W→Wjumps do not exist in the process. These findings provide further support to our previous conclusion about the absence of the W→W jumps in the process of benzene diffusion in NaY. Finally, to relations, for predicting the self-and MS difthsivities were derived and found to be in fair agreement with the KMC and MD simulations.