GENERALIZED DEACTIVATION EQUATION OF CATALYST IN HYDRODESULFURIZATIONOF LIGHT AND HEAVY OILS

In this paper,each deactivation of catalyst for start,middle,and end o f run in the hydrodesulfurization (HDS) process is theoretically inter preted as the behavior due to the reduction of active sites and effect ive diffusivity that is caused by coking and deposition of metal (Ni, V). In the previous report, catalyst deactivation in HDS was viewed as a model of simple simultaneous equations assuming that deactivation w as the sum of first -order reduction rate of different active sites. I n this study, furthermore,based on a long-term test using Arabian heav y atmospheric residue, a deactivation model due to diffusivity within the catalyst pores is made and an overall deactivation equation interp reting the ail behaviors of deactivation through a HDS run is develope d by adding the diffusion model to the previous active site model. In this report,the concept of the new kinetic model and method to determi ne the deactivation parameters that compose the overall deactivation e quation are described, and also various catalyst deactivations in HDS of light and heavy oils are analyzed by the new equation,The analytica l results agree with all deactivation behaviors. Furthermore,the deact ivation parameter obtained by analysis are discussed with the physical properties of the catalysts, and the applicability of the overall dea ctivation equation is also referred.