Gas-phase isomerization of meta-xylene over USY zeolite in a Riser Simulator: a simplified kinetic model

The gas-phase isomerization of meta-xylene has been carried out over USY zeolite catalyst using a fluidized bed reactor under relevant reaction conditions for FCC (temperature, contact time, reactant partial pressure, catalyst/oil ratio). Experimental results clearly indicate the presence of bimolecular isomerization pathway, in addition to the monomolecular isomerization reaction. The disproportionation/isomerization (D/I) ratio was found to increase steadily with both m-xylene conversion and reaction temperature, whereas p-xylene/o-xylene (P/O) ratio was only mildly affected with both reaction parameters. A simplified kinetic model based on reactant-converted (RC) deactivation model was developed for the reaction and compared with the obtained experimental data. The apparent kinetic parameters were estimated using nonlinear regression analysis.