Catalysts for hydrorefining of secondary distillates

Two-stage scheme of hydrorefining of secondary distillates was presented. Hydrogenation of diene and partial hydrogenation of monoolefin hydrocarbons of secondary stock took place at the first stage. The second stage comprised hydrorefining of hydrogenation product with finish hydrogenation of monoolefin hydrocarbons. Special catalysts were developed on the base of Ni-Mo-Al₂O₃ system. The catalyst IP-70 of the first stage contained optimum active components and carrier providing hydrogenation of di- and monoolefin hydrocarbons. The catalyst GDS-1 was developed for the second stage. The catalyst was highly-desulfurizing and permitted to remove monoolefin hydrocarbons. The properties of the catalysts were achieved by increasing content of nickel-molybdenum structures weakly bound with carrier by simultaneous introduction of active components into carrier by coextrusion and into pore volume by saturation with active component salts. The catalysts were tested in micropilot plants during 5000 h. Depth of hydrogenation of olefins was 99 %, desulfurization degree was 98 %.