Molybdenum sulfide was prepared dry in argon by a media-agitating milling for ultra-deep desulfurization of diesel oil. Effect of volume fraction of grinding media on the characteristics of comminuted molybdenum sulfide was investigated.
The active specific surface area of the comminuted molybdenum sulfide calculated from chemical adsorption isotherm of hydrogen gas increased with the volume fraction of grinding media, whereas the BET specific surface area obtained from physical adsorption of nitrogen gas first increased with the volume fraction and reached plateau at the volume fraction of 44%. The catalytic activities such as hydrogenation of 1-methylnaphthalene (1-MN) and hydro-desulfurization (HDS) of dibenzothiophene (DBT) increased with the volume fraction of grinding media. The catalytic activities were well correlated with the active specific surface area. Reaction path in HDS of 4, 6-dimethyldibenzothiophene (4, 6-DMDBT), refractory constituents in diesel oil, with the comminuted molybdenum sulfide was different from that with the conventional Co-Mo supported catalyst. Hydrogenation followed by desulfurization is the main reaction path in the former while direct desulfurization in the latter. The comminuted molybdenum sulfide desulfurized 4, 6-DMDBT to a larger extent than the conventional Co-Mo supported catalyst, which indicated that molybdenum sulfide comminuted in media-agitating mills is promising catalyst for ultra-deep desulfurization of diesel oil.