Single-component diffusion data on propane, propylene and isobutane in zeolite 13X were obtained by using molecular dynamics simulations; especially with regard to their dependence upon temperature and concentration. The results were critically compared with experiment and previous simulation data, where available. The diffusion coefficients were computed by taking the framework cations of zeolite 13X into consideration. Simulation results were presented for propylene diffusion in faujasite frameworks. From the mean squared displacements, self-diffusion coefficients of 7.5 x 10-9, 9.1 x 10-9 and 9.6 x 10-10m2/s for 2mol/unit-cell were calculated for propane, propylene, and isobutane at 373K, respectively. The simulations showed that the diffusivity decreased with increasing loading for all of these adsorbates. Transport diffusivities were estimated from the self-diffusion coefficient and the equilibrium adsorption isotherms by using the Darken equation.

Diffusion of Propane, Propylene and Isobutane in 13X Zeolite by Molecular Dynamics. M.A.Granato, M.Jorge, T.J.H.Vlugt, A.E.Rodrigues: Chemical Engineering Science, 2010, 65[9], 2656-63