Kinetic model and analysis method of catalyst deactivation in hydrodesulfurization of light and heavy oils

Abstract

Catalyst deactivation in hydrodesulfurization (HDS) of petroleum distillates is caused by coking alone but deactivation in HDS of residue is due to a combination of coking and the deposition of metals, such as Ni and V. The objective of the present study is to determine the HDS activity of commercial catalysts affected by coke, metals and so on. According to a long term test for catalyst deactivation using light gas oil, vacuum gas oil and atmospheric residue, we proposed a kinetic model of simple simultaneous equations that supposed the mechanism of catalyst deactivation as a first-order reduction of different active sites in HDS of light and heavy oils. We hypothesized that the deactivating species are composed of two types : one that loses activity easily and the other that does not and derived an analysis method. This deactivation equation could successfully express the deactivation behaviors in extensive HDS, and was confirmed to be applicable to the various catalyst deactivations of light and heavy oils. © 1995, The Society of Chemical Engineers, Japan. All rights reserved.