Influence of the order of the catalysts in the stacked bed of VGO hydrotreating catalysts

[Display omitted] •Influence of catalysts order and ratio in the bed loading was studied.•NiMo/Al2O3 had the highest HDS and HDN activities of the model and real feed.•SRVGO should be treated firstly by NiMo and then by CoMo catalysts.•The best ratio of NiMo/Al2O3 to CoMo/Al2O3 and catalysts was 40/60 vol%. The influence of the order of catalysts and their ratio in the bed for FCC feedstock hydrotreatment was investigated. CoMo/Al2O3 and NiMo/Al2O3 catalysts were prepared in the laboratory and studied by nitrogen adsorption–desorption, XPS and HRTEM methods. The catalysts were tested in hydrotreatment of model feedstocks. It was found that NiMo/Al2O3 catalyst had the highest activity in conversion of the model feedstock containingsulfur and nitrogen compounds. The best results were obtained for the feedstockfirstly treated by NiMo/Al2O3 and then by CoMo/Al2O3. Catalysts were tested separately and together in hydrotreatment of SRVGO. The order of catalysts and their ratio were varied. The best combination included NiMo/Al2O3 catalyst at the top of the reactor and CoMo/Al2O3 at the bottom of the reactor in the ratio of 40/60 vol%.