MFI沸石中Maxwell-Stefan扩散系数与覆盖率的关系  

Occupancy dependence of M-S diffusivity of single component in MFI zeolite

作　　者：张舟[1] 刘辉[1] 陈标华[1] 

机构地区：[1]北京化工大学可控化学反应科学与技术基础教育部重点实验室,北京100029

出　　处：《化工学报》2005年第11期2054-2058,共5页CIESC Journal

基　　金：教育部科学技术研究重点项目(02017);国家重点基础研究发展规划项目(2004CB217804).~~

摘　　要：基于描述多孔介质中表面扩散的Maxwell-Stefan(M-S)方程,结合本文动力学Monte Carlo(KMC)模拟及文献中分子动力学(MD)模拟数据,提出了MFI沸石中M-S扩散系数与覆盖率依赖关系的新表达式.该关系式考虑了分子间相互作用以及饱和吸附覆盖量对扩散系数与覆盖率依赖关系的影响,用于预测强受限组分CF4、弱受限组分CH4以及中度受限组分Xe等7种单组分在MFI沸石中的M-S扩散系数时,结果较现有其他关系式更为合理.A new occupancy-dependence equation of M-S diffusivity in MFI zeolite was developed based on Kinetic Monte Carlo simulation results obtained in this paper and Molecular Dynamics simulation data from literature. The new relation took into account the effects of sorbate-sorbate interaction and saturated adsorption loading by incorporating terms of the L-J energy parameter and saturation loading, and yielded better results than previous equations when calculating M-S diffusivity of weakly confined component CH4, strongly confined component CF4 and moderately confined components such as Ar, Xe, SF6, Ne and He in MFI zeolite.

关 键 词：扩散系数 覆盖率 MAXWELL-STEFAN方程 MFI沸石 动力学Monte Carlo 

分 类 号：O414.2[理学—理论物理]