Abstract: The invention concerns the manufacture of a solid acid catalyst comprising: (a) a carrier, (b) a metal of the platinum family and (c) an additional metal selected from tin, germanium and lead. Halogen may be present.The additional metal is added to the catalytic mass dissolved in a hydrocarbon solvent, in the form of an organometallic compound, for example tetrabutyl tin.The invention is particularly applicable to the manufacture of catalysts for hydrocarbon reforming or aromatic hydrocarbons production.

Abstract: A heavy hydrocarbon charge containing sulfur, asphaltenes and/or resins is hydrotreated in the liquid phase at 250.degree.-500.degree. C. under a pressure of 20-350 bars in the presence of a catalyst previously obtained by reacting an organic compound of a transition metal with an organic aluminum compound, in a hydrocarbon free of asphaltene and resin.The transition metal organic compound is advantageously an iron, nickel, cobalt, molybdenum, tungsten or vanadium acetylacetonate or carboxylate.

Abstract: Catalytic cracking or steam cracking effluents are desulfurized without substantial decrease of their octane number by subdividing said effluent into two fractions of different boiling ranges, the heavier of which is admixed with hydrogen, the resulting mixture being completely vaporized and fed to a hydrodesulfurization zone containing a first bed of selective catalyst formed of cobalt and molybdenum, or cobalt and tungsten, or nickel and molybdenum or nickel and tungsten deposited on a non-acid carrier, and a second bed of conventional hydrodesulfurization catalyst, the effluent from the hydrodesulfurization zone being cooled down and fractionated to separate a hydrocarbon fraction of the gasoline range which is recombined with the lighter fraction of said effluent.