Abstract:

In order to explore the catalytic activity of in-situ and off-site pre-sulfidation catalysts,the same batch of Ni-W oxida-tion catalyst was prepared by equal volume impregnation method.The physicochemical properties,catalytic activities and physicochemical properties of the three fresh catalysts were investigated.Three kinds of catalysts prepared from the processes of in-situ and off-site pre-sulfidation.The physical-and-chemical properties,catalytic activity and use physical-and-chemical properties of the three kinds of fresh catalysts were studied.The results showed that with the increase of sulfur loading amount on the catalyst,the bulk density of the pre-sulfidation catalyst increased,the specific surface area,pore volume and average pore diameter decreased,and the distribution of the pre-sulfidation catalyst in various pore sizes decreased.Among the three catalysts,the atom percentage of W ⁴⁺ metal and NiWS active phase on the catalyst with high sulfur loading was the highest,followed by the in-situ sulfurization catalyst,and the lowest was the off-site presulfurization catalyst with low sulfur loading.Under the conditions of pressure of 3.0 MPa,reaction space velocity of 1.0 h ^-1and hydrogen to oil volume ratio of 400∶1,the activity of catalysts was evaluated under different reaction temperatures with the distillate from Suizhong second-line and third-line as raw materials.Results showed that the activity of deacidification,desulfurization and denitrification of the off-site pre-sulfidation catalyst with high sulfur loading was the highest,followed by the in-situ sulfurization catalyst,and the catalytic activity of the off-site pre-sulfidation catalyst with low sulfur loading was the worst.

Key words: in-situ sulfurization, off-site sulfurization, hydrodeacidification, activity of catalyst, characterization of catalyst