Impact of Metal Content on the Deactivation of a Bifunctional Hydrocracking Catalyst

The catalytic performance of a hydrocracking bifunctional catalyst and consequently its activity loss depend on the balance between metal (M) acid (A) functions. Commonly, function is reputed to stabilize should therefore alleviate deactivation. In order test this hypothesis, study aimed assess impact oxide (MoO3) content deactivation vacuum gasoil (nickel-molybdenum sulfide dispersed carrier containing USY zeolite). To do so, two catalysts with different contents were submitted under specific operating conditions promoting deactivation, i.e., high temperature (T = 418 °C) space velocity (LHSV 3 h–1). Experiments carried out in pilot unit hydrotreated VGO feedstock 120 ppmw organic nitrogen. was measured by following decrease both conversion (370 °C+) apparent kinetic constants for main reactions (cracking, hydrodenitrogenation, aromatics hydrogenation) time stream. aged catalysts, sampled from three reactor locations, characterized elemental textural analyses thermogravimetry investigate quantity nature coke deposits. determine residual hydrogenation functions, tests model compounds (toluene n-heptane) out. It observed that feedstocks nitrogen concentration, causes substantial increase compounds’ concentration bed. This significantly reduces available sites hence activity. However, at same time, M/A ratio modified favor function. better low loading results lower deposition rate than higher content.