Abstract: A conversion process of hydrocarbon oils comprises at least a hydrodemercaptanization process, wherein said hydrodemercaptanization process comprises contacting a feedstock with a hydrofining catalyst containing a tungsten oxide and/or a molybdenum oxide, a nickel oxide and a cobalt oxide supported on an alumina under the conditions of hydrodemercaptanization, in which the content of said tungsten oxide and/or molybdenum oxide is from 4 wt % to less than 10 wt %, the nickel oxide content is 1-5 wt %, the cobalt oxide content is 0.01-1 wt % based on the catalyst, and the ratio of total atom number of nickel and cobalt to total atom number of nickel, cobalt, tungsten and/or molybdenum is 0.3-0.9. Said process can be carried out at a lower temperature and a lower H/oil volume ratio.

Abstract: A hydrotreating catalyst containing molybdenum and/or tungsten for light oil distillates, said catalyst contains tungsten oxide and/or moybdenum oxide, nickel oxide and cobalt oxide supported on an alumina carrier, the content of said tungsten oxide and/or molybdenum oxide is from 4 wt % to less than 10 wt %, the content of nickel oxide 1.about.5 wt %, the content of cobalt oxide 0.01.about.1 wt %, the atom ratio of nickel-cobalt to nickel, cobalt-tungsten and/or molybdenum is 0.3.about.0.9. Compared with the prior art, the catalyst has lower metal content, but higher activity at low-temperature. The catalyst is especially suitable for use in the hydrodemercaptanization process of light oil distillates.