Hydrocracking catalyst for hydrocarbon oil, method for producing hydrocracking catalyst, and method for hydrocracking hydrocarbon oil with hydrocracking catalyst

A hydrocracking catalyst for the high boiling fraction containing hydrocarbon oil comprising a hydrogenative metal component carried on a support containing an ultra-stable Y-type zeolite,

• wherein the ultra-stable Y-type zeolite is a framework-substituted zeolite (hereinafter referred to as a framework-substituted zeolite-1) in which a part of aluminum atoms constituting a zeolite framework thereof is substituted with zirconium atoms and titanium ions,
• said zeolite-1 has a crystallinity of 80% or more, and contains from 0.1 to 5 mass % zirconium atoms and from 0.1-5 mass % titanium atoms as calculated as the oxide basis, and
• a relative decomposition rate as defined below is 99% or more, and a relative middle distillate yield as defined below is 95% or more:
• (Relative decomposition rate and relative middle distillate yield)
• hydrocarbon oil as raw material oil is subjected to hydrocracking on the conditions of a hydrogen partial pressure of 13 MPa, a liquid hourly space velocity of 0.26 hr−1, a hydrogen-to-oil ratio (hydrogen/oil ratio) of 1,250 Nm3/kL, and a reaction temperature of 370° C. to obtain produced oil;
• a decomposition rate is calculated according to an equation (2) as defined below;
• a middle distillate yield is calculated according to an equation (3) as defined below;
• the relative decomposition rate is a relative value of the decomposition rate with the proviso that a decomposition rate obtained through hydrocracking with a use of a hydrocracking catalyst A as defined below is taken as a base of 100;
• and the relative middle distillate yield is a relative value of the middle distillate yield with the proviso that a middle distillate yield obtained through hydrocracking with a use of the hydrocracking catalyst A as defined below is taken as a base of 100;
• Decomposition rate (%)={1−(Content (kg) of a fraction having a boiling point of higher than 375° C. in the produced oil/Content (kg) of a fraction having a boiling point of higher than 375° C. in the raw oil)}×100 Equation (2):
• Middle distillate yield (%)={Content (kg) of a fraction having a boiling point of 149 to 375° C. in the produced oil/Content (kg) of a fraction having a boiling point of lower than 375° C. in the raw oil}×100 Equation (3):
• (Hydrocracking catalyst A)
• 40 kg of a sodium aluminate aqueous solution having 6.8 mass % of Al2O3 and 40 kg of an aluminum sulfate aqueous solution having 2.4 mass % of Al2O3 are mixed;
• the resultant mixture is diluted with water to have 10 mass % of Al2O3;
• pH is adjusted with aqueous ammonia to 10.5;
• an alumina knead product that has been obtained by kneading with a kneader is mixed with a zirconium-substituted zeolite (USY(A)) as defined below at a dry mass ratio of 1:1;
• the mixture is formed into a columnar shape having a diameter or 1.8 mm;
• the columnar article is fired at 550° C. for 3 hours to thereby obtain a support A,
• 700 ml of water is added to 201.3 g of molybdenum trioxide and 90.4 g of nickel carbonate as hydrogenative metal components to thereby prepare an aqueous solution;
• the support A is impregnated with the aqueous solution;
• the resultant article is fired in air at 550° C. for 1 hour to thereby obtain a catalyst as hydrocracking catalyst A;
• (Zirconium-substituted zeolite (USY(A))
• 50.0 kg of a NaY-type zeolite having a SiO2/Al2O3 molar ratio of 5.2, a crystal lattice constant of 2.466 nm, a specific surface area of 720 m2/g, and a Na2O content of 13.0 mass % is suspended in 500 liters of water at 60° C.;
• 14.0 kg of ammonium sulfate is added thereto to thereby prepare a Y-type zeolite (NH465Y) in which 65% of sodium contained in the NaY-type zeolite has been ion-exchanged with ammonium ion;
• 40 kg of the Y-type zeolite (NH465Y) is fired in a saturated steam atmosphere at 670° C. for 1 hour to obtain a hydrogen type Y-type zeolite, which is then suspended in water at 60° C.;
• and 49.0 kg of ammonium sulfate is added thereto to thereby prepare a Y-type zeolite (NH495Y) in which 95% of Na contained in the NaY-type zeolite was ion-exchanged with NH4;
• 33.0 kg of the Y-type zeolite (NH495Y) is fired in a saturated steam atmosphere at 650° C. for 1 hour to thereby prepare a ultra-stable Y-type zeolite (USY(a)) having a SiO2/Al2O3 molar ratio of 5.2 and a Na2O content of 0.60 mass %;
• 26.0 kg of the ultra-stable Y-type zeolite (USY(a)) is suspended in water at 60° C.;
• 61.0 kg of 25 mass % sulfuric acid is added thereto to thereby prepare a ultra-stable Y-type zeolite (USY(b)),
• the ultra-stable Y-type zeolite (USY(b)) is fired at 600° C. for 1 hour to thereby prepare a ultra-stable Y-type zeolite (USY(c)), and
• 1 kg of the ultra-stable Y-type zeolite (USY(c)) is suspended in water at 25° C.;
• pH of the suspension is adjusted to 1.6 with 25 mass % sulfuric acid;
• 86 g of a solution containing 18 mass % zirconium sulfate is added and mixed thereto, to thereby obtain a zirconium-substituted zeolite as zirconium-substituted zeolite (USY(A)).