PURPOSE: To obtain the title base oil with excellent oxidation stability by the nuclear hydrogenation of hydrocarbon oil obtd. by hydro (thermally) cracking a coal-base raw material such as coal tar (pitch) or coal liquid.
CONSTITUTION: A coal-base raw material such as coal tar (pitch), coal liquid or coal liquefaction pitch is subjected to hydro (thermal) cracking in the pres ence of a catalyst comprising at least one metal component selected from Group VI and/or Group VIII metals of the periodic table, such as Mo, W, Ni or Co, supported on a carrier such as Al2O3 under conditions including a pressure of 20W300kg/cm2 G, a temp. of 250W500°C, a liquid space velocity of 0.01W100hr-1 and a liquid/gas ratio of 100W5,000lH2/l oil, to obtain a hydrocar bon oil of a boiling range of 200W600°C and of S and N content each ≤1,000ppm contg. 50wt% or more condensed polycyclic component with 2W10 rings. Then it is refined by sulfuric acid washing and/or solid adsorption after nuclear hydrogenation in the presence of a metal catalyst such as Ni or Pt at 50W300°C and 10W200kg/cm2 G.
FURUMOTO MASASHI
OISHI TAIJI
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