Monte Carlo simulations of self- and transport-diffusivities of 2-methylhexane in silicalite

We report kinetic Monte Carlo (KMC) simulations of self- and transport-diffusivities of 2-methylhexane (2MH) in silicalite. The hopping rates of 2MH along the straight and zig-zag channels were chosen based on the calculations of Smit (Faraday Discuss., 1997, 106, 93). The self-diffusivity tensor was found to exhibit anisotropy and strongly dependent on the occupancy or loading. The degree of anisotropy of the self-diffusivity tensor decreases with loading, a hitherto unreported result. The loading dependence is shown to be due to correlation effects. Such correlation effects, do not however influence the behavior of the transport-diffusivity which exhibits a predictable Langmuirian dependence on loading.

[1]  Alexis T. Bell,et al.  Dynamic Monte-Carlo and mean-field study of the effect of strong adsorption sites on self-diffusion in zeolites , 1999 .

[2]  B. Smit,et al.  Influence of isotherm inflection on diffusion in silicalite , 1999 .

[3]  E. Webb,et al.  Intracrystalline Diffusion of Linear and Branched Alkanes in the Zeolites TON, EUO, and MFI , 1999 .

[4]  D. Theodorou,et al.  Molecular Dynamics Simulation of n-Butane−Methane Mixtures in Silicalite , 1999 .

[5]  B. Smit,et al.  Molecular Simulations of Adsorption Isotherms for Linear and Branched Alkanes and Their Mixtures in Silicalite , 1999 .

[6]  H. Jobic,et al.  Diffusion of Isobutane in ZSM-5 Zeolite: A Comparison of Quasi-Elastic Neutron Scattering and Supported Membrane Results , 1999 .

[7]  B. Smit,et al.  Sorption-Induced Diffusion-Selective Separation of Hydrocarbon Isomers Using Silicalite , 1998 .

[8]  Alexis T. Bell,et al.  Effect of topology and molecular occupancy on self-diffusion in lattice models of zeolites—Monte-Carlo simulations , 1998 .

[9]  S. Auerbach,et al.  Modeling the concentration dependence of diffusion in zeolites. II. Kinetic Monte Carlo simulations of benzene in Na-Y , 1997 .

[10]  A. Chakraborty,et al.  Diffusion and reaction in ZSM-5 studied by dynamic Monte Carlo , 1997 .

[11]  B. Smit,et al.  Simulation of adsorption and diffusion of hydrocarbons in zeolites , 1997 .

[12]  Diffusion of interacting lattice gases on heterogeneous surfaces with simple topographies , 1996 .

[13]  Berend Smit,et al.  Understanding molecular simulation: from algorithms to applications , 1996 .

[14]  R. Krishna,et al.  The Maxwell-Stefan approach to mass transfer , 1997 .

[15]  W. H. Weinberg,et al.  Theoretical foundations of dynamical Monte Carlo simulations , 1991 .

[16]  J. Kaerger Random walk through two-channel networks: a simple means to correlate the coefficients of anisotropic diffusion in ZSM-5 type zeolites , 1991 .

[17]  David A. Reed,et al.  Surface diffusivity and the time correlation of concentration fluctuations , 1981 .

[18]  David Chandler,et al.  Statistical mechanics of isomerization dynamics in liquids and the transition state approximation , 1978 .