Molecular simulation of propane-propylene binary adsorption in Zeolite 13X

Abstract

In the present work, a recently developed force field for molecular simulation of the adsorption properties of linear alkanes in the sodium form of faujasite (FAU), MFI, and MOR-type zeolites is applied to reproduce experimental results of propane adsorption properties in zeolite 13X. The Lennard-Jones (LJ) parameters for interactions between the sp²-hybridized bond of propylene and the other atoms of this system are successfully determined by fitting against experimental isotherms. This new set of parameters allows the calculation of adsorption properties of propane-propylene mixtures, as well as the isosteric heat of single-component adsorption of propane and propylene in zeolite 13X. Good agreement between simulation results and experimental data for propane and propylene adsorption loadings at temperatures of 303, 323, 343, 373, 423, and 473 K and pressures in the range of 0.2-110 kPa confirms the applicability of the force field. In addition, molecular simulation will be used to guide the desorbent choice for propane/propylene separation by cyclic adsorptive processes.