Effect of feedstock properties on the kinetics of hydrocracking of heavy oils

Abstract

The ability to predict changes in selectivity and quality of products of catalytic hydrocracking reaction is essential for the performance and economics of the process due to the variation in properties of the fractions derived from heavy crude oils. The influence of different hydrocarbon feedstocks on hydrocracking reaction kinetics was analyzed using detailed experimental data reported in the literature. A six–lump kinetic model in the presence and absence of diverse catalysts was used. For the predictions of the pseudocomponent yields using the estimated kinetic parameters, global average absolute error values less than 4.3 % concerning the experimental data were obtained. Clear trends are observed between the values of some reaction rate coefficients and properties of the diverse feedstocks. The analysis of the effect of feedstock properties on the kinetic parameters indicated that streams with high API and low H/C ratio have higher global reaction rate coefficients of vacuum residue conversion, observing an increase of up to three–fold the coefficient values concerning the rise of asphaltene content. The contents of carbon residue and sulfur influence the performance of certain reaction pathways and the production of coke for the different feedstocks studied and types of catalysts.