FIELD: chemistry.
SUBSTANCE: present invention relates to a process for producing a gas oil fraction, heavy distillate fraction and a residual base oil fraction from Fischer-Tropsch derived feedstock. Method includes the following steps: (a) directing the feedstock to a hydroprocessing step to produce at least partially isomerised feedstock; (b) separating the isomerised feedstock by means of distillation into at least a gas oil fraction, a heavy distillate fraction having distillation temperature T90 wt% of 400 to 550°C, and a residual fraction, the residual fraction having a distillation temperature T10 wt% of 200 to 450°C; (c) recycling from more than 20 to not more than 70 wt% of the residual fraction to step (a) and (d) catalytic dewaxing of the remaining residual fraction to obtain a residual base oil.
EFFECT: proposed method makes it possible to improve the quality and / or yield of the fractions obtained.
14 cl, 1 dwg, 2 tbl, 2 ex
