Kinetic model of the n-octane hydroisomerization on PtBeta agglomerated catalyst:: Influence of the reaction conditions

The aim of this work was to study the influence of the reaction conditions in the hydroisomerization of n-octane over beta agglomerated zeolite, using platinum as the hydrogenating/dehydrogenating function. From the obtained data, a kinetic model was constructed to obtain the fundamental rate coefficients of the hydroisomerization reaction. The influence of the temperature was studied first, observing higher n-octane conversions with increasing temperature. The opposite effect was observed for the isomer selectivity. Next, it was observed that n-octane conversion decreased with the total pressure of the reaction, with the opposite effect being observed for the isomer selectivity. The effect of the reaction pressure in suppressing cracking and simultaneously promoting isomerization was attributed to the increase in the partial pressure of hydrogen. A similar effect was observed when the molar hydrogen/n-octane ratio was studied due to a better removal of alkenes species. When the influence of the contact time was studied, the conversion of n-octane increased as the contact time increased, while the selectivity to isomers decreased. It was observed that the ratio isomerized to cracked n-octane decreased as the contact time increased. Finally, the influence of the time-on-stream was studied, and no change in the time-on-stream runs of 30 h was observed. The n-octane hydroisomerization was simulated using a single kinetic model, based on a lumped reaction network for the main reaction. The excellent agreement between the experimental and calculated evolution of the different reaction parameters, as a function of the reaction conditions, was confirmed.