Hydrocracking of n-heptane with a NiO-MoO3/HYUS zeolite as catalyst. Kinetic study

The hydrocracking of n-heptane has been carried out in a fixed bed reactor at 2.45 MPa pressure and with a H₂/n-heptane molar ratio of 5.0 using a 4 wt% NiO - 8 wt% MO₃/HYUS zeolite as a catalyst. The W/F₁₀ ratio was varied between 75.3 and 1624 kg · s/kmol at different reaction temperatures: 573, 588, 603 and 623 K. The kinetics of the reaction has been studied by two different procedures due to the slight deactivation of the catalyst. One of them uses the conversion and yield values extrapolated at time on stream to zero and the other uses a kinetic equation where the deactivation of the catalyst has been included. The experimental data were fit well by a pseudo-first order kinetic equation and the kinetic constant values obtained by both methods coincide. The apparent activation energy of the reaction has a value of 105.8 + 5.0 kJ/mol.