Patent ID: 8691076

Claim:
A method of manufacturing naphthenic base oil from an oil fraction of fluidized catalytic cracking, comprising: (a) separating a light cycle oil and a slurry oil from an oil fraction obtained through fluidized catalytic cracking of petroleum hydrocarbon; (b) hydrotreating the light cycle oil, the slurry oil or a mixture thereof, separated in step (a), under conditions of temperature of 280-430° C. pressure of 120-200 kg/cm 2 , liquid hourly space velocity (LHSV) of 0.2-3 hr −1 and a volume ratio of hydrogen to the fed oil fraction of 1500-2500 Nm 3 /n 3 in presence of a hydrotreating catalyst; (c) dewaxing a whole hydrotreated oil fraction; obtained wholly from step (b), from which only the gaseous components are removed, under conditions of temperature of 280-430° C., pressure of 30-200 kg/cm 2 , liquid hourly space velocity (LHSV) of 0.2-3 hr −1 and a volume ratio of hydrogen to the fed oil fraction of 300-1500 Nm 3 /m 3 in presence of a dewacing catalyst; and (d) separating a dewaxed oil fraction obtained in step (c), according to a range of viscosity, wherein all of steps (a) through (d) are conducted sequentially and successively, wherein said light cycle oil, the slurry oil or a mixture thereof has a total aromatic content of 60 wt % or more, and a poly-aromatic content of 55.8 wt % to 72.4 wt %, wherein, the oil fraction hydrotreated in step (a) has a poly-aromatic content of not more than 10 wt %, wherein the naphthenic base oil has a viscosity index of 85 or less, at least 30% of the carbon bonds of the naphthenic base oil being naphthenic type, and wherein the naphthenic base oil has a naphthene content equal to or greater than 35 wt %.