The catalytic transformation of toluene has been investigated over Y-zeolite-based catalysts in a novel riser simulator under different operating conditions. Several experiments were performed in the temperature range of 400- 500 degrees C to understand the transformation of toluene over a high-acidity Y-based zeolite catalyst (HY). It has been observed that toluene can transform either through disproportionation, producing benzene and xylene isomers, or through dealkylation, producing gases and benzene. The rates of both reactions are essentially dependent on the reaction temperature. The dealkylation reaction was determined to be favored by high temperature. The benzene/ xylene ratio was determined to increase with temperature, because of the high xylene dealkylation rate. Toluene transformation was determined to be controlled by both Y-zeolite acidity and reaction temperature. While high acidity and high reaction temperature favor toluene dealkylation, medium acidity and low reaction temperature favor toluene disproportionation. Pseudo-homogeneous first-order kinetics was used to model toluene conversion. Two different deactivation functions were included in this model, and the kinetic constants were calculated based on these two different functions.