Using separate kinetic models to predict liquid, gas, and coke yields in heavy oil hydrocracking

Abstract

A kinetic model based on distillation curves for predicting the liquid fractions composition (residue, vacuum gas oil, middle distillates, and naphtha) in heavy crude oil hydrocracking was developed, whereby the yield of each liquid fraction can be calculated. The experiments were carried out in a 1.8 L batch reactor at reaction temperature of 360-400 ?C, hydrogen pressure of 3.9 MPa, and reaction times of 2-5 h, using a heavy crude oil as feed and mineral catalyst. This kinetic model was combined with another one based on SARA, gas, and coke composition, and with both models the yield of the different liquid fractions, gas, and coke can be predicted with good accuracy. Based on the values of the reaction rate coefficients, it was determined that some reaction pathways do not occur at low temperature. The average absolute error between experimental and calculated composition was lower than 3.3% indicating the high accuracy of the proposed kinetic model.