Hydrotreating of Straight-Run Diesel Fraction over Mixed NiMoWS/Al2O3 Sulfide Catalysts

Abstract

The catalytic properties of trimetallic NiMoWS catalysts supported on alumina are studied in the process of straight-run diesel fraction hydrotreating. It is shown that the nature of the oxide precursor of the mixed NiMoWS active phase strongly affects catalyst activity in the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrogenation (HYD) of polycyclic aromatic hydrocarbons (PAH). The NiMoWS/Al₂O₃ catalyst synthesized from the mixed H₄SiMo₃W₉O₄₀ heteropoly acid is more efficient than the sample prepared from a mixture of individual H₄SiMo₁₂O₄₀ and H₄SiW₁₂O₄₀ heteropoly acids in both HDS and HDN transformations at the same metal content. The highest activity in PAH hydrogenation is exhibited by the NiMoWS/Al₂O₃ catalyst prepared using H₄SiMo₃W₉O₄₀.