Process and catalysts for deep desulphurization of fuels

摘要

Oxidative desulfurization of hydrotreated hydrocarbon mixtures comprises putting these mixtures in contact, in the presence of an organic peroxide, with a catalytic composition comprising a completely amorphous micro and/or mesoporous mixed oxide containing an oxide matrix, preferably silica, alumina, ceria and/or magnesia, wherein at least one oxidative metal oxide, preferably metal oxide or group IVA metal oxide is uniformly dispersed. Oxidative desulfurization of hydrotreated hydrocarbon mixtures which boil at 180-360[deg]C containing less than 350 ppm sulfur as thiophenic compounds comprises putting these mixtures in contact, in the presence of an organic peroxide, with a catalytic composition comprising a completely amorphous micro and/or mesoporous mixed oxide containing an oxide matrix, preferably silica, alumina, ceria and/or magnesia, wherein at least one oxidative metal oxide, preferably metal oxide or group IVA metal oxide is uniformly dispersed; and separating the obtained corresponding sulfur oxygenated products from the hydrocarbon mixture. Independent claims are also included for: (1) catalytic composition comprising a completely amorphous micro-mesoporous mixed oxide consisting of a silica and alumina matrix wherein oxides of titanium, zirconium, vanadium or tin are uniformly dispersed and having a surface area of more than 500 m2>/g, a pore volume of 0.3-1.3 mL/g, an average pore diameter of less than 40 Å, and an X-ray diffraction (XRD) spectrum from powders than does not have a crystalline structure and does not show any peak; and (2) a process for preparing the catalytic composition by subjecting to hydrolysis and gelation a solution of soluble or hydrolysable compound(s) of silicon and aluminum in alcohol with an aqueous solution of a hydroxide of tetraalkylammonium of formula R'4N-OH and of soluble or hydrolysable compound(s) of titanium, vanadium, zirconium and/or tin at a temperature close to the boiling point, at atmospheric pressure of the alcohol used and of any alcohol which develops as by-product of the above hydrolysis reaction, without the elimination of the alcohols from the reaction environment, preferably at 20-80[deg]C; subjecting the gel to drying; outgassing the material in vacuum and then adding a solution of silylating agent in solvent under inert gas; and refluxing the resulting mixture under inert atmosphere and then filtering the product, washing and subjecting to drying. R' : 3-7C alkyl. The ratio of alcohol to oxide matrix is 5-20. The ratio of R'4N-OH to oxide matrix is 0.05-0.5. The ratio of water to oxide matrix is 5-30. The ratio of oxide matrix to metal oxide is >=5. The ratio of water (H2O) to R'4-N+> varies according to the number of carbon atoms in the R' alkyl chain. When R' is hexyl, H2O/R'4N+> is greater than 133. When R' is pentyl, H2O/R'4N+> is greater than 100. When R' is butyl, H2O/R'4N+> is greater than 73. When R' is propyl, H2O/R6'4N+> is greater than 53.