PURPOSE: To treat petroleum at a low cost with a simple apparatus by distilling a crude oil under the normal pressure to separate it into a residual oil and a distillate oil and hydrogenating the distillate oil collectively with one hydrogenation apparatus.
CONSTITUTION: A crude oil pretreated, e.g. dewatered and desalted, is fed to a rough-distillation apparatus 11, distilled under the normal pressure, and thus separated into a light oil, a distillate oil comprising fractions more volatile than the light oil, and a residue (a normal-pressure residual oil). The distillate oil is collectively fed to a hydrogenation apparatus 12 and where brought into contact with hydrogen in the presence of a catalyst to be subjected to hydrogenation such as desulfurization. The resulting refined oil is fractionated into a refined light oil, a refined kerosene, a refined heavy naphtha, a refined light naphtha, a refined LP gas, and an off-gas (a light gas). Thus, the construction of a petroleum refinery system is greatly simplified and the construction cost and equipment space are greatly reduced in comparison with the conventional method wherein a crude oil is distilled and separated into various fractions and then each fraction is hydrogenated separately.
TASHIRO NATSUO
OGAWA AKINORI
TSUCHIYA FUJIO
INOMATA MAKOTO