Comparison of parallel and in-series reaction schemes for kinetic modeling of VGO hydrocracking

Abstract

An analysis of the reaction pathways developed during the hydrocracking of vacuum gas oil (VGO) was carried out using kinetic models based on parallel and in-series reaction schemes. A methodology that considers diverse crucial factors was applied for the estimation of kinetic parameters based on experimental data reported for VGO hydrocracking using a Ni-Mo-F3.6/ASA-Al2O3 catalyst in a temperature range of 380-410 ?C and 10 mPa. The results of a kinetic model that considers parallel reaction pathways presented a better fit than kinetic parameters reported in the literature. While, models based on in-series reaction schemes indicated that some reaction pathways present considerable values of the kinetic coefficients. Every set of kinetic parameters was analyzed by sensitivity analysis, parity plot, and residual analysis to ensure that these values are the most suitable for the experimental data and reaction scheme used. Each kinetic model presented an adequate fit with the experimental data, obtaining values of AAE less than 5 %.