Study of Bifunctional Hydrocracking and Hydroisodeparaffinization Catalysts Based on Zeolites and Alumophosphates, Part 1: Effect of the Nature and Activity of the Hydrogenating and Acidic Components on the Activity and Selectivity of Hydrocracking Catalysts

The resistance to sulfur compounds is considered for nickel, platinum, and palladium metals deposited onto acidic supports, depending on the nature of a support. Catalysts containing nickel, platinum, palladium, and their sulfides as hydro-dehydrogenating components are studied in the reaction of n-octane hydrocracking. The supports are HY, ZSM-5, ZSM-23, and ZSM-12 zeolites and SAPO-11 and SAPO-31 silicoalumophosphates. It is shown that the deposited metals in the hydrocracking catalysts have different resistances to sulfur compounds, regardless of the properties of the acidic support under the conditions of the reaction. The hydrocracking process follows two different pathways, depending on the nature of the hydro–dehydrogenating component (a metal or its sulfides), its activity, and the ratio between the activities of the acidic and hydrogenating components. The first of these determines the predominant cracking of the initial paraffin at the initial stage, while the initial paraffin is subjected to dehydrogenation on the second pathway.