Abstract: In the hydrocarbon oil production method, mixed oil containing atmospheric residue and deasphalted oil is brought into contact with a demetallizing catalyst in the presence of a hydrogen gas, and the mixed oil subjected to the demetallizing process is brought into contact with a desulfurizing catalyst in the presence of a hydrogen gas. The demetallizing catalyst optionally includes a low-reactivity catalyst. A part of a metallic composition contained in the mixed oil is a decomposable metallic composition. The amount of vanadium in the decomposable metallic composition is x % relative to the amount of vanadium in a whole vanadium-containing compound, the volume of the low-reactivity catalyst is y vol % relative to the total demetallizing catalyst: 0<x100, 0<y?100, and x?50?y2.6x?99.

Abstract: In the hydrocarbon oil production method, mixed oil containing atmospheric residue and deasphalted oil is brought into contact with a demetallizing catalyst in the presence of a hydrogen gas, and the mixed oil subjected to the demetallizing process is brought into contact with a desulfurizing catalyst in the presence of a hydrogen gas. The demetallizing catalyst optionally includes a low-reactivity catalyst. A part of a metallic composition contained in the mixed oil is a decomposable metallic composition. The amount of vanadium in the decomposable metallic composition is x % relative to the amount of vanadium in a whole vanadium-containing compound, the volume of the low-reactivity catalyst is y vol % relative to the total demetallizing catalyst: 0<x 100, 0<y?100, and x?50?y 2.6x?99.

Abstract: A method for hydrodesulfurization which comprises introducing partially desulfurized oil, which is a light oil fraction containing sulfur, and hydrogen to a reactor packed with a hydrodesulfurization catalyst, wherein the partially desulfurized oil has a sulfur content of 2000 ppm or less and preferably a polycyclic aromatic compound content of 3 wt % or more, wherein the amount of hydrogen sulfide contained in the partially desulfurized oil and hydrogen introduced to the reactor is 1.5 mol % or less with respect to that of the hydrogen introduced, and wherein the hydrodesulfurization catalyst comprises a carrier comprising a porous inorganic oxide and also comprises tungsten and one of nickel and cobalt as a metal component supported on the carrier. The method allows the production of a desulfurized light oil having a sulfur content of 50 ppm or less without the use of a special crude oil, and under operation conditions providing high productivity.

Abstract: Hydrorefining catalyst contains 0.1 to 25 wt % in total of at least one hydrogenation active metal element selected from elements of Group 6, Group 8, Group 9, and Group 10 of the Periodic Table, and 0.1 to 3 wt % potassium on a carrier formed of porous inorganic oxide. The concentration distribution of the hydrogenation active metal element is higher in the central part than in the peripheral part of the catalyst, and the concentration distribution of potassium is higher in the peripheral part than in the central part of the catalyst. The pores on the outside surface of the catalyst are not plugged by the metal content of hetero compounds and hetero compounds can be efficiently diffused to inside the catalyst. As a result, long-term retention of a state of high activity is possible.