Abstract: After the residue hydrotreating spent catalysts were washed with toluene for removing soluble hydrocarbon components, the catalysts were characterized by C-S elementanalysis, XRF and N₂ adsorption-desorption. The results showed that along the flow direction the pore volume and specific surface area of the spent catalysts first increased and then decreased, while those of the regenerant increased gradually, the irreversible deactivation caused by metal deposition was becoming less and less. For spent catalysts, the range of hysteresis loop N2 adsorption-desorption widened and pore size deceased. The pore structure was damaged badly for the guard catalyst, guard-demetallization transition catalysts and demetallization catalysts, and could not be recovered after regeneration, mainly due to the large amount of metal deposit. After deactivation, the pore structure loss of metal-desulfurization transition agent, desulfurizer and reducing residual carbon agent was small, and coke deposition was the main cause of deactivation. Finally, three kinds of deactivation mechanisms were summarized, and some suggestions were put forward for the design of pore structure of residue hydrotreating catalyst.

Key words: residue hydotreating, catalyst, deactivation, pore structure, Metal impurity deposition, coke deposition