METHOD FOR PRODUCING LOW-SULPHUR DIESEL FUEL Russian patent published in 1997 - IPC

FIELD: petroleum processing industry; production of low-sulphur Diesel oil by subjecting crude petroleum to hydrofining. SUBSTANCE: novelty of method resides in fact that hydrofining process is carried out in two steps, gas/feedstock mixture being subjected to heating between steps. During first step, hydrofining uses aluminium-nickel-molybdenum catalyst, in which pores have, predominantly, radii 9-12 nm, whereas during second process step aluminium-nickel-molybdenum or aluminium-cobalt-molybdenum catalysts are used having, predominantly, pores with radii 4-8 nm, first-step-to-second-step catalysts being used in weight ratio 1:2-6. Process is conducted at temperature 250-350 C in first step and at 320-380 C in the second step. EFFECT: higher degree of desulphurization of crude petroleum by hydrofining. 2 cl, 1 tbl