Sorption and diffusion of aromatic hydrocarbons on modified Y-zeolites

Abstract

The rates of sorption of benzene, toluene, ethylbenzene and styrene on FeNaY have been studied. The equilibrium sorption capacities of aromatic hydrocarbons over FeNaY show the following trend: benzene > toluene > ethylbenzene = styrene. The sorption of styrene is almost irreversible in the temperature range of 24°-300°C, on fresh catalysts due to polymerization of styrene. The polymerized styrene is trapped in the supercages of FeNaY zeolite. The equilibrium sorption for styrene decreases from 29.45 to 27.32 molecules per unit cell in the temperature range of 24° to 300°C. On the other hand, the sorption for ethylbenzene decreases from 27.56 to 10molecules per unit cell in the temperature of 24°-300°C. The diffusion coefficients and apparent energies of activation for diffusion suggest the following trend of diffusion: benzene > toluene > ethylhenzene » styrene.