Hydrocarbon oil production method

1. A hydrocarbon oil production method, comprising:

a demetallizing process in which mixed oil containing atmospheric residue and deasphalted oil is brought into contact with a demetallizing catalyst in the presence of a hydrogen gas; and

a desulfurizing process in which the mixed oil subjected to the demetallizing process is brought into contact with a desulfurizing catalyst in the presence of a hydrogen gas, wherein

the demetallizing catalyst includes at least a low-reactivity catalyst and a high-reactivity catalyst,

the low-reactivity catalyst is a catalyst having lower hydrogenating activity than that of the high-reactivity catalyst,

the low-reactivity catalyst has a porous carrier and a Group VI element supported on the carrier,

a content of a Group VIII element is 0 mass % or more based on a catalyst mass in the low-reactivity catalyst,

a volume ratio of the high-reactivity catalyst is more than 0 vol % relative to the total demetallizing catalyst,

the high-reactivity catalyst has a porous carrier and a Group VI element and a Group VIII element supported on the carrier,

the content of the Group VIII element based on the catalyst mass in the low-reactivity catalyst is lower than a content of the Group VIII element based on the catalyst mass in the high-reactivity catalyst,

the mixed oil contains a vanadium-containing component,

a part of the vanadium-containing component is a decomposable metallic composition having a molecular weight of 3000 or less, which is measured by gel permeation chromatography, and

wherein the amount of vanadium to be contained in the decomposable metallic composition is x % relative to the amount of vanadium to be contained in the vanadium-containing component and the volume ratio of the low-reactivity catalyst is y vol % relative to the total demetallizing catalyst, the following inequality expression is established:

0< x< 100,

0< y< 100, and

x− 50< y< 2.6 x− 99.

2. The hydrocarbon oil production method according to claim 1 , wherein a content of the Group VI element based on the catalyst mass in the low-reactivity catalyst is lower than a content of the Group VI element based on the catalyst mass in the high-reactivity catalyst.

3. The hydrocarbon oil production method according to claim 1 , wherein

the Group VI element in the low-reactivity catalyst and the high-reactivity catalyst is at least one of molybdenum or tungsten, and

the Group VIII element in the low-reactivity catalyst and the high-reactivity catalyst is at least one of nickel or cobalt.

4. The hydrocarbon oil production method according to claim 1 , wherein

a content of a Group VI element oxide based on a catalyst mass in the low-reactivity catalyst is from 1 mass % to less than 8 mass %, and

a content of a Group VIII element oxide based on a catalyst mass in the low-reactivity catalyst is from 0 mass % to less than 1 mass %.

5. The hydrocarbon oil production method according to claim 1 , wherein, in the demetallizing process,

a reaction temperature is from 350 to 450° C.,

a partial pressure of the hydrogen gas is from 5 to 25 MPa,

a liquid hourly space velocity is from 0.1 to 3.0 h −1 , and

a hydrogen/oil ratio is from 400 to 1500 Nm 3 /m 3 .

6. The hydrocarbon oil production method according to claim 1 , wherein, in the desulfurizing process,

a reaction temperature is from 350 to 450° C.,

a partial pressure of the hydrogen gas is from 5 to 25 MPa,

a liquid hourly space velocity is from 0.1 to 3.0 h −1 , and

a hydrogen/oil ratio is from 400 to 1500 Nm 3 /m 3 .

7. The hydrocarbon oil production method according to claim 1 , wherein

the content of a Group VI element oxide based on the catalyst mass in the high-reactivity catalyst is from 8 mass % to less than 30 mass %, and

the content of a Group VIII element oxide based on the catalyst mass in the high-reactivity catalyst is from 1 mass % to less than 10 mass %.