 
Summary: Modeling the concentration dependence of diffusion in zeolites. II. Kinetic
Monte Carlo simulations of benzene in NaY
Chandra Saravanan
Department of Chemistry, University of Massachusetts, Amherst, MA 01003
Scott M. Auerbacha)
Departments of Chemistry and Chemical Engineering, University of Massachusetts, Amherst,
Massachusetts 01003
Received 12 June 1997; accepted 14 August 1997
We have performed kinetic Monte Carlo simulations of benzene diffusion in NaY at finite loadings
for various temperatures to test the analytical theory presented in Paper I, immediately preceding
this paper. Our theory and simulations assume that benzene molecules jump among SII and W sites,
located near Na ions in 6rings and in 12ring windows, respectively. The theory exploits the fact
that supercages are identical on average, yielding D 1
6k a2
a2
/6 1 1 Keq(12) , where
k is the cagetocage rate coefficient, Keq(12) is the WSII equilibrium coefficient, 1 is the
mean W site residence time, and is the transmission coefficient for cagetocage motion. The
simulations use fundamental rate coefficients calculated at infinite dilution for consistency with the
theory in Paper I. Our theory for k , Keq(12) and 1 agrees quantitatively with simulation for
