Modeling of gas transport in a microporous solid using a slice selection procedure: Application to the diffusion of benzene in ZSM5

被引:18
作者
Petryk, Michel [3 ]
Leclerc, Sebastien [4 ]
Canet, Daniel [4 ]
Fraissard, Jacques [1 ,2 ]
机构
[1] Univ Paris 06, F-75005 Paris 05, France
[2] ESPCI, F-75005 Paris 05, France
[3] Univ Tech Etat Ivan Puluy, Ternopol, Ukraine
[4] Nancy Univ, Methodol RMN, Vandoeuvre Les Nancy, France
关键词
NMR imaging; Mathematical modeling of diffusion; Intercrystallite diffusion in zeolite; Intracrystallite diffusion in zeolite; Diffusion of benzene in ZSM5;
D O I
10.1016/j.cattod.2008.05.034
中图分类号
O69 [应用化学];
学科分类号
081704 ;
摘要
The analytical solution of the equations of gas diffusion in a heterogeneous zeolite bed is presented. The problem is handled by assuming that the bed consists of a large number of very thin layers of solid, perpendicular to the direction of propagation of the gas. Mass transfer by diffusion in such a material is determined by a system of differential equations with boundary and interface conditions. The results allow us to make the theoretical determination of the time dependence of the concentration profiles and the inter- and intracrystallite diffusion coefficients of a gas in each layer of the bed. A numerical application concerns the diffusion of benzene in a cylindrical bed of ZSM5 displaced vertically and rapidly, step-by-step, inside the NMR probe. Thus, the time dependence of the concentration of gas absorbed at the level of each slice and each crystallite can be obtained. These coupled investigations give a better understanding of the diffusion process in this multilayer material. (C) 2008 Elsevier B.V. All rights reserved.
引用
收藏
页码:234 / 240
页数:7
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