Abstract: A catalyst composition for converting hydrocarbons in a hydrotreatment process (hydrodesulfurization and/or hydrodenitrogenization) and simultaneously cracking them, containing an alumina-silica-alumina carrier built up from alumina and silica-alumina, on which hydrogenation metals, such as molybdenum, nickel, and/or cobalt, have been provided and which also contains a catalytically active amount of boron, generally in the range of 1 to 20 wt. %. The invention also relates to a process for the preparation of such a catalyst, with boron being provided ahead of the Group VIII component. The carrier material used may be made up of mixtures of alumina and amorphous silica-alumina or of mixtures of alumina and silica-coated alumina. The catalyst composition is highly suitable for converting vacuum gas oil into middle distillate oils by hydrotreating.

Abstract: Ex situ presulfidation of hydrotreating catalysts comprising impregnating the catalysts with an aqueous solution of an organic sulfur compound, e.g. the diammonium salt of 2,5-dimercapto-1,3,4-thiadiazole and 2,2'-dithiodiethanol, followed by drying of the impregnated material. The dried material is activated by contacting it with hydrogen gas at elevated temperature.

Abstract: Disclosed are the preparation of a sulfided catalyst and the use of said catalyst in the hydrotreatment of hydrocarbon feeds. The sulfidation is carried out by ex situ presulfiding of a fresh or regenerated catalyst, followed by the resulting material being contacted in situ at elevated temperature with hydrogen gas in combination with either a sulfiding agent, e.g., hydrogen sulfide, or a spiked feed.

Abstract: Disclosed is a process for the ex situ presulfidation of hydrotreating catalysts employing organic sulfur compounds with a boiling point exceeding 100.degree. C. and satisfying the formulaX--R.sup.1 (S--R.sup.2).sub.p S--R.sup.3 --Y (I)wherein p=0, 1 or 2,R.sup.1, R.sup.2, and R.sup.3 may be the same or different and represent alkylene groups having 1-4 carbon atoms,X and Y may be the same or different and have the meaning of --H, --OH, --OR.sup.4 4 or --C(O)OR.sup.5, whereinR.sup.4 has the meaning of an alkyl group or acyl group with 1-3 carbon atoms, andR.sup.5 has the meaning of --H, an ammonium group or an alkyl group with 1-3 carbon atoms.Also disclosed is a process for activating the thus presulfided catalyst.