Modeling of hydrodesulfurization catalysts. I. Influence of catalyst pore structures on the rate of demetallization

A mathematical model to describe catalyst deactivation during residuum hydrodesulfurization (HDS) has been applied to catalyst systems of different pore structures. Simulations were carried out on the hydrodemetallization (HDM) reaction, which usually leads to the steady accumulation of metals during HDS. Catalyst activity decays with time both linearly and nonlinearly depending on the pore structure. Predicted lifetimes for three different pore structures show that the catalyst can deactivate within 5-15 months. The results of the simulations indicate that better service life could be achieved with improved catalyst design involving pore structure modifications.