KINETICS OF ZEOLITE-CATALYZED TOLUENE ISOPROPYLATION

The isopropylation of toluene to cymene was studied over medium-pore z eolite ZSM-5. The influence of the operating parameters on the product distribution was studied and a reaction mechanism already established was used to develop a kinetic model. At temperatures above 548 K nega tive apparent activation energies were obtained which were ascribed to the increased diffusion resistances at higher temperatures. Apparent activation energies were corrected to intrinsic activation energies by taking into account the heats of adsorption and the activation energy for diffusion.