Industrial & Engineering Chemistry Research, Vol.47, No.4, 1043-1050, 2008
Kinetic modeling for assessing the product distribution in toluene hydrocracking on a Pt/HZSM-5 catalyst
A kinetic model has been proposed to quantify the distribution of product lumps in the hydrocracking of toluene on a bifunctional catalyst prepared by physically mixing Pt/gamma-Al2O3 with high-acidity HZSM-5 zeolite (Si/Al = 15). The current model is based on one that was previously proposed for the hydrogenolytic cracking of methylcyclohexane, given that this is the limiting step because of the rapid hydrogenation of toluene. The experimental results used for calculating the kinetic parameters were obtained in an isothermal fixed-bed reactor under a wide range of operating conditions (250-450 degrees C; WHSV = 2.85-100 h(-1), tau = 1.0-3.5 g(zeolite) h g(toluene)(-1)); pressure = 20-60 bar; molH(2)/mol(toluene) = 19-59; conversion = 0- 100% (integral reactor). The model faithfully predicts the effects of operating conditions on the product distribution and is suitable for use in the optimization of C2+ n-alkane production.