Patent ID: 7384537

Claim:
A method of manufacturing refined oil, which comprises the step of bringing feed oil into contact with hydrogen in the presence of a demetalizing/desulfurizing catalyst and a hydrogenolysis catalyst to obtain the refined oil having a viscosity of 20 cst or lower at 135° C., a pour point of 30° C. or lower, an alkali metal content of 1 wt ppm or less, a vanadium content of 10 wt ppm or less, and a sulfur content of 0.3 wt % or lower, wherein: the demetalizing/desulfurizing catalyst includes a carrier that contains at least one of alumina and silica-alumina, and the carrier supports at least one member selected from the group consisting of nickel, cobalt, molybdenum, and tungsten; the hydrogenolysis catalyst includes a component having cracking capability, or isomerization activity and a component having hydrogenation activity; the component having cracking activity or isomerization activity is at least one member selected from the group consisting of silica, alumina, magnesia, zirconia, boria, titania, calcia and zinc oxide; the component having hydrogenation activity is at least one member selected from the group consisting of nickel, cobalt, molybdenum, platinum, chromium, tungsten, iron, and palladium; the liquid space velocity (LHSV) of the feed oil and the hydrogen with respect to the demetalizing/desulfurizing catalyst is set to a range of 0.1 to 3/hr; the liquid space velocity (LHSV) of the feed oil and the hydrogen with respect to the hydrogenolysis catalyst is set to a range of 10 to 30/hr; and the feed rate of hydrogen is set so that the partial pressure of hydrogen falls in a range from 50 to 160 kg/cm 2 .