Dynamics of active sites transformation in HDS‐HDA catalyst

Abstract

Benzene hydrogenation in steady‐state and unsteady‐state regimes over sulfide Ni‐W/γ‐Al2O3 catalyst is studied. The mechanism and dynamic model of hydrogenation and hydrogenolysis active sites transformation are proposed. The reactions were shown to be quasi steady‐state ones with slow poisoning of both hydrogenation and hydrogenolysis active sites by the formation of intermediate surface compounds of sulfur. The dynamic behavior was described by the proposed model with sufficient accuracy.

Kinetic behavior of benzene hydrogenation and thiophene hydrogenolysis on sulfide Ni-Mo/Al2O3 catalyst

“…A difficult problem of the HDA-HDS processes on sulfide catalysts is mutual inhibition of hydrogenation by sulfurorganic compounds and of hydrogenolysis by aromatics. In our paper [3], we have considered an unsteady-state kinetic scheme of a simultaneous performance of the benzene hydrogenation and thiophene hydrogenolysis on the sulfide (Ni, Mo) and (Ni, W) catalysts. However, that scheme did not take into account the decrease in the HDA activity that appears when thiophene is absent from the reaction mixture for a long period of time.…”