Impact of Feedstock Properties on the Deactivation of a Vacuum Gas Oil Hydrocracking Catalyst

The aim of this study was to understand the impact vacuum gas oil (VGO) properties on deactivation rate a hydrocracking catalyst (nickel–molybdenum sulfide dispersed carrier containing USY zeolite). For purpose, two hydrotreated feeds different densities, organic nitrogen (∼120–150 ppmw) and aromatic content, were hydrocracked under operating conditions that favor deactivation, is, high temperature (T = 418 °C) space velocity (LHSV 3 h–1). performance followed by measuring VGO conversion (370 °C+ petroleum cut) determining apparent kinetic constants for main reactions (cracking, hydrodenitrogenation, hydrodesulfurization, aromatics hydrogenation). experiments stopped after times stream (either 6 or 30 days) in order assess evolution as function time. spent catalysts, obtained from three reactor locations, characterized elemental textural analyses thermogravimetry investigate quantity nature coke formed. Catalytic tests with model compounds (toluene n-heptane) carried out determine residual activity hydrogenating acid functions. It found that, at evaluated conditions, both content feedstock have determinant role rate. Organic determines ratio between available metal sites. generate precursors Both factors play coupled promotes deposition surface, which leads an increase top end boiling point feed.