Process for producing hydrocarbon oil

1. A method for manufacturing a hydrocarbon oil, comprising:

a first step wherein a feedstock oil containing an oxygen-containing organic compound and a water-insoluble chlorine-containing compound is brought into contact with a hydrogenation catalyst comprising a support containing a porous inorganic oxide and one or more metals selected from Group VIA and Group VIII of the periodic table supported on the support in the presence of hydrogen to generate a hydrocarbon oil and water in a vapor state by the hydrodeoxygenation of the oxygen-containing organic compound and convert the water-insoluble chlorine-containing compound into a water-soluble chlorine-containing compound;

a second step wherein the water in the reaction product of the first step is maintained in a vapor state and the reaction product of the first step is brought into contact with a nitrogen-containing Brønsted base compound which has a boiling point at normal pressure of 100° C. or less and is water-soluble, to obtain a product to be treated; and

a third step wherein the product to be treated is cooled to a temperature not higher than the temperature at which the water in a vapor state is liquefied to form an aqueous phase containing a water-soluble chlorine-containing compound and a nitrogen-containing Brønsted base compound and then separate the aqueous phase from an oil to be treated to obtain a product oil containing a hydrocarbon oil.

2. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein an oxygen content in the feedstock oil is 1 to 15% by mass and a chlorine content in the feedstock oil is 0.1 to 50 ppm by mass, based on the total amount of the feedstock oil.

3. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein in the first step, 2 to 1200 kg of water is produced as a by-product per gram of a chlorine content in the feedstock oil.

4. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein in the second step, the reaction product is brought into contact with 0.4 to 8 g in terms of the nitrogen atom of a nitrogen-containing Brønsted base compound per gram of the chlorine content in the feedstock oil.

5. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein the nitrogen-containing Brønsted base compound is ammonia.

6. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein the oxygen-containing organic compound contained in the feedstock oil is an oil and fat derived from an animal or vegetable oil and the ratio of a fatty acid and/or a compound having an ester structure in the oil and fat derived from an animal or vegetable oil is 90% by mole or more.

7. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein the porous inorganic compound comprises two or more elements selected from aluminum, silicon, zirconium, boron, titanium and magnesium.

8. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein in the first step, the feedstock oil and the hydrogenation catalyst are brought into contact together under the conditions of a hydrogen pressure of 2 to 10 MPa, a liquid hourly space velocity of 0.1 to 3.0 h −1 , a hydrogen/oil ratio of 150 to 1500 NL/L and a reaction temperature of 150 to 380° C.

9. The method for manufacturing a hydrocarbon oil according to claim 1 , wherein an oxygen content in the product oil is 1% by mass or less, a chlorine content in the product oil is 0.1 ppm by mass or less and an iodine value in the product oil is 0.1 or less, based on the total amount of the product oil.