Pseudoboehmite, method for producing pseudoboehmite, method for producing carrier, and method for producing hydrogenation refining catalyst

Abstract

Provided is a pseudoboehmite used as a raw material of a highly active hydrogenation refining catalyst. The crystallite diameter D020 of the pseudoboehmite in a direction perpendicular to the (020) plane of the pseudoboehmite is 2.0-3.5 nm. The crystallite diameter D120 of the pseudoboehmite in a direction perpendicular to the (120) plane of the pseudoboehmite is 2.5-4.5 nm. D020 / D120 is 0.8-1.3. The volume of pores having a pore diameter of 20-600 Å among the pores in the pseudoboehmite is 0.80-1.20 ml / g. The volume of the pores is measured by the nitrogen adsorption method. The pH that indicates the isoelectric point of the pseudoboehmite in water is 8.8 or more.

Description

Pseudo-boehmite, method for producing pseudo-boehmite, method for producing carrier, and method for producing hydrotreating catalyst

[0001] The present disclosure relates to pseudo-boehmite, a method for producing pseudo-boehmite, a method for producing a support using pseudo-boehmite, and a method for producing a hydrorefining catalyst using pseudo-boehmite.

[0002] Heavy oils such as petroleum residual oils (e.g., vacuum residues) are subjected to hydrorefining to reduce impurities (sulfur, metal, and asphaltene contents). In hydrorefining, heavy oils are brought into contact with a hydrorefining catalyst at high temperature and pressure in the presence of hydrogen. As a result, a product oil is obtained from which the sulfur, metal, and asphaltene contents have been removed or decomposed. Supports for hydrorefining catalysts are made from pseudoboehmite, and hydrorefining catalysts are produced by supporting active components such as Group 6 elements and Group 8 to 10 elements on the support (see Patent Documents 1 and 2 listed below).

[0003] International Publication No. 99 / 03783 Patent No. 5227134

[0004] An object of one aspect of the present invention is to provide pseudo-boehmite that can be used as a raw material for a hydrotreating catalyst having excellent activity, a method for producing pseudo-boehmite, a method for producing a carrier using pseudo-boehmite, and a method for producing a hydrotreating catalyst using pseudo-boehmite.

[0005] For example, as described in the following [1] to [8], one aspect of the present invention relates to pseudo-boehmite, a method for producing pseudo-boehmite, a method for producing a support using pseudo-boehmite, and a method for producing a hydrorefining catalyst using pseudo-boehmite.

[0006] [1] The crystallite diameter D of the pseudo-boehmite in the direction perpendicular to the (020) plane of the pseudo-boehmite ０２０ is 2.0 nm or more and 3.5 nm or less, and the crystallite diameter D of the pseudo-boehmite in the direction perpendicular to the (120) plane of the pseudo-boehmite １２０ is 2.5 nm or more and 4.5 nm or less, and D ０２０ / D １２０is 0.8 or more and 1.3 or less, the volume of pores having a pore diameter of 20 Å or more and 600 Å or less is 0.80 ml / g or more and 1.20 ml / g or less, the pore volume is measured by a nitrogen adsorption method, and the pH indicating the isoelectric point of the pseudo-boehmite in water is 8.8 or more.

[0007] [2] The pseudo-boehmite according to [1], which contains at least one Group 4 element, and the total content of the Group 4 elements is 0.01% by mass or more and 1.0% by mass or less.

[0008] [3] A method for producing pseudo-boehmite according to [1] or [2], comprising: a first step of supplying a first aqueous solution containing an aluminum salt and a second aqueous solution containing an alkali metal aluminate into a reaction vessel containing heated water, thereby generating pseudo-boehmite seed crystals in the reaction liquid in the reaction vessel; a second step of adjusting the pH of the reaction liquid to 8.5 or more after the first step; a third step of supplying a masking reagent to the reaction liquid and supplying the second aqueous solution to the reaction liquid, thereby adjusting the pH of the reaction liquid to 8.5 or more after the second step; and a fourth step of supplying the first aqueous solution and the second aqueous solution to the reaction liquid and maintaining the reaction liquid basic, thereby growing the seed crystals in the reaction liquid, wherein the masking reagent is at least one compound selected from the group consisting of a salt containing at least one Group 4 element, a surfactant, a glycol, an organic acid, and an organic acid salt.

[0009] [4] The method for producing pseudo-boehmite according to [3], wherein the masking reagent is at least one compound selected from the group consisting of sulfates, nitrates, hydrochlorides, and organic acid salts.

[0010] [5] A method for producing a carrier, comprising: a step of kneading raw materials containing the pseudo-boehmite according to [1] or [2] and a deflocculating agent to form a dough; a step of forming a molded body from the dough; and a step of calcining the molded body to obtain a carrier.

[0011] [6] A method for producing a hydrorefining catalyst, comprising: a step of kneading raw materials containing the pseudo-boehmite according to [1] or [2] and a deflocculating agent to form a dough; a step of forming a molded body from the dough; a step of calcining the molded body to obtain a carrier; and a step of supporting an active component on the carrier.

[0012] [7] The method for producing a hydrorefining catalyst according to [6], wherein the active component contains at least one Group 6 element and at least one element selected from Groups 8 to 10 elements.

[0013] [8] The method for producing a hydrorefining catalyst according to [6], wherein the active component comprises at least one Group 6 element, at least one element selected from Groups 8 to 10, and phosphorus.

[0014] According to one aspect of the present invention, there are provided pseudo-boehmite used as a raw material for a highly active hydrotreating catalyst, a method for producing pseudo-boehmite, a method for producing a carrier using pseudo-boehmite, and a method for producing a hydrotreating catalyst using pseudo-boehmite.

[0015] Fig. 1 is a schematic perspective view showing the (020) and (010) planes in a unit cell of pseudo-boehmite (orthorhombic crystal), Fig. 2 is a schematic perspective view showing the (120) plane in a unit cell of pseudo-boehmite (orthorhombic crystal), and Fig. 3 is a schematic perspective view showing the (001) plane in a unit cell of pseudo-boehmite (orthorhombic crystal).

[0016] Preferred embodiments of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following embodiments.

[0017] The support (γ-alumina) and hydrotreating catalyst according to this embodiment are produced from the pseudo-boehmite according to this embodiment. The hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment has at least one catalytic activity among desulfurization activity, demetalization activity, denitrogenation activity, and hydrocracking activity. The hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment may have all of desulfurization activity, demetalization activity, denitrogenation activity, and hydrocracking activity. For example, the hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment can achieve both high desulfurization activity and high demetalization activity.

[0018] (Pseudo-boehmite) Pseudo-boehmite is alumina monohydrate and is represented by γ-AlOOH. In the respective production methods of a carrier and a hydrorefining catalyst using pseudo-boehmite as a raw material, calcination of the pseudo-boehmite causes a topotactic transformation of the pseudo-boehmite, thereby forming γ-alumina having a desired morphology from the pseudo-boehmite while maintaining the morphology (e.g., the basic crystal structure) of the pseudo-boehmite. The crystalline structure of pseudo-boehmite is an orthorhombic crystal, while the crystalline structure of γ-alumina is a defective spinel structure. Information on pseudo-boehmite, including its X-ray diffraction (XRD) pattern and lattice constants, is registered in the JCPDS card (JCPDS 21-1307). The JCPDS card is widely used as standard data for the crystal structure of pseudo-boehmite. Figures 1, 2, and 3 are schematic diagrams of the unit cell uc of the crystal structure (orthorhombic) of pseudo-boehmite. The a-axis, b-axis, and c-axis, which indicate the orientation of the orthorhombic crystal, are perpendicular to each other. For example, the lattice constant a (i.e., the spacing between (100) planes) of pseudo-boehmite in the a-axis direction (i.e., the

[100] direction) may be approximately 0.380 nm. For example, the lattice constant b (i.e., the spacing between (010) planes) of pseudo-boehmite in the b-axis direction (i.e., the

[010] direction) may be approximately 1.223 nm. For example, the lattice constant c (i.e., the spacing between (001) planes) of pseudo-boehmite in the c-axis direction (i.e., the

[001] direction) may be approximately 0.286 nm. The lattice constants a, b, and c are not limited to the values ​​described above.

[0019] Any lattice plane of pseudo-boehmite is expressed as an (hkl) plane, where h, k, and l are Miller indices. The crystallite diameter D of pseudo-boehmite in the direction perpendicular to the (hkl) plane is ｈｋｌ is measured based on the Debye-Scherrer method. The crystallite diameter D of pseudo-boehmite in the direction perpendicular to the (hkl) plane ｈｋｌis calculated from the following Scherrer equation (Equation 1): K and λ in Equation 1 are known constants, and β and θ in Equation 1 are determined based on the XRD pattern of pseudo-boehmite. ｈｋｌ =(Kλ) / (βcosθ) (1)

[0020] In Formula 1, K is the Scherrer constant. For example, the Scherrer constant K may be 0.94. In Formula 1, λ is the wavelength of the incident X-rays incident on the pseudo-boehmite. For example, the incident X-rays may be CuKα1 rays. For example, the wavelength λ of CuKα1 rays may be 0.154056 nm. However, the incident X-rays are not limited to CuKα1 rays. In Formula 1, β is the full width at half maximum (FWHM) of the diffracted X-ray peak of the (hkl) plane in the XRD pattern of the pseudo-boehmite. The unit of β may be degrees. In Formula 1, θ is the Bragg angle, which is 1 / 2 of the diffraction angle 2θ. The Bragg angle θ is the angle between the incident X-rays and the (hkl) plane. The diffraction angle 2θ is the angle between the incident X-ray and the diffracted X-ray of the (hkl) plane. The unit of θ may also be degrees. For example, the diffraction angle 2θ of the (020) plane of pseudo-boehmite may be 13.728°. For example, the diffraction angle 2θ of the (120) plane of pseudo-boehmite may be 27.976°. K, λ, and 2θ in Equation 1 are not limited to the above values. The internal standard sample used in the Debye-Scherrer method may be α-alumina obtained by firing high-purity pseudo-boehmite at 1600°C for 36 hours. The internal standard sample may be silicon (Si), a standard sample manufactured by the National Institute of Standards and Technology (NIST).

[0021] At least a part of or the entire pseudo-boehmite according to this embodiment is crystalline. The pseudo-boehmite according to this embodiment may be in the form of a powder (a large number of particles). One particle (crystalline particle) of pseudo-boehmite may consist of one crystallite (i.e., single crystal), or one particle of pseudo-boehmite may consist of multiple crystallites (i.e., polycrystal). The technical features described below are unique to the pseudo-boehmite according to this embodiment.

[0022] FIG. 1 shows the (020) plane of pseudo-boehmite. The crystallite diameter D of pseudo-boehmite in the direction perpendicular to the (020) plane of pseudo-boehmite is ０２０ is 2.0 nm or more and 3.5 nm or less, preferably 2.3 nm or more and 3.2 nm or less, more preferably 2.5 nm or more and 3.0 nm or less. ０２０ The crystallite diameter D may be 2.84 nm or more and 2.99 nm or less. ０２０ If the crystallite diameter D is too small, the particle size of the pseudo-boehmite crystal particles will also be small, which significantly deteriorates the handling properties of the pseudo-boehmite in industrial processes such as filtration, washing, and drying. ０２０ If the crystallite diameter D is too large, the particle size of the crystal particles of pseudo-boehmite will also be large, and the specific surface area and pore volume of γ-alumina obtained by calcining the pseudo-boehmite will decrease, resulting in a significant decrease in the activity of the hydrorefining catalyst using γ-alumina as a carrier. ０２０ When the amount of the pseudo-boehmite is within the above range, the handling property of the pseudo-boehmite is improved, and the activity of the hydrorefining catalyst produced from the pseudo-boehmite is improved.

[0023] 2 shows the (120) plane of pseudo-boehmite. The crystallite diameter D of pseudo-boehmite in the direction perpendicular to the (120) plane of pseudo-boehmite is １２０ is 2.5 nm or more and 4.5 nm or less, preferably 3.0 nm or more and 4.0 nm or less. １２０ The crystallite diameter D may be 2.89 nm or more and 3.72 nm or less, or 3.05 nm or more and 3.72 nm or less. １２０If the crystallite diameter D is too small, the particle size of the pseudo-boehmite crystal particles will also be small, which significantly deteriorates the handling properties of the pseudo-boehmite in industrial processes such as filtration, washing, and drying. １２０ If the crystallite diameter D is too large, the particle size of the crystal particles of pseudo-boehmite will also be large, and the specific surface area and pore volume of γ-alumina obtained by calcining the pseudo-boehmite will decrease, resulting in a significant decrease in the performance of the hydrorefining catalyst using γ-alumina as a carrier. １２０ When the amount of the pseudo-boehmite is within the above range, the handling property of the pseudo-boehmite is improved, and the activity of the hydrorefining catalyst produced from the pseudo-boehmite is improved.

[0024] D ０２０ / D １２０ is 0.8 or more and 1.3 or less, preferably 0.8 or more and 1.2 or less, and more preferably 0.8 or more and 1.1 or less. ０２０ / D １２０ may be 0.804 or more and 0.983 or less, or 0.804 or more and 0.951 or less. Since the (020) plane is parallel to the (010) plane (basal plane), D ０２０ / D １２０ means the relative degree of stacking of the (010) plane. ０２０ / D １２０ is an index showing the degree of exposure of the (001) plane (a lattice plane perpendicular to the (010) plane) of pseudo-boehmite. Figure 3 shows the (001) plane of pseudo-boehmite. The (001) plane of γ-alumina, which constitutes the support of the hydrorefining catalyst, exhibits excellent catalytic activity. Since the (001) plane of γ-alumina originates from the (001) plane of pseudo-boehmite, which is the raw material of γ-alumina, D, an index related to pseudo-boehmite, ０２０ / D １２０ D is also an index showing the degree of exposure of the (001) plane of γ-alumina constituting the support of the hydrorefining catalyst. ０２０ / D １２０ When the surface roughness is within the above range, the (001) plane of the γ-alumina constituting the support of the hydrorefining catalyst is sufficiently exposed, and excellent catalytic activity resulting from the (001) plane of the γ-alumina is easily obtained. ０２０ / D １２０If it is outside the above range, the (001) plane of γ-alumina is not sufficiently exposed.

[0025] Pseudo-boehmite is porous. That is, pseudo-boehmite contains a plurality (numerous) of pores. The volume PV-p of pores in pseudo-boehmite having a pore diameter of 20 Å or more and 600 Å or less is 0.80 ml / g or more and 1.20 ml / g or less, preferably 0.85 ml / g or more and 1.10 ml / g or less, and more preferably 0.90 ml / g or more and 1.05 ml / g or less. The volume PV-p of pores having a pore diameter of 20 Å or more and 600 Å or less may be 0.84 ml / g or more and 1.09 ml / g or less. The unit ml / g means the pore volume (unit: ml) per unit mass (unit: g) of pseudo-boehmite. The nitrogen adsorption method has superior measurement accuracy (resolution) to other measurement methods (e.g., mercury intrusion porosimetry) in the pore diameter range of 20 Å or more and 600 Å or less. Therefore, the volume of pores with a pore diameter of 20 Å or more and 600 Å or less is measured by nitrogen adsorption. If the volume PV-p of pores with a pore diameter of 20 Å or more and 600 Å or less is too small, the specific surface area and pore volume of γ-alumina obtained by calcining pseudo-boehmite are reduced, and the activity of a hydrorefining catalyst using γ-alumina as a carrier is significantly reduced. If the volume PV-p of pores with a pore diameter of 20 Å or more and 600 Å or less is too large, the bulk density of a hydrorefining catalyst using γ-alumina as a carrier is unnecessarily reduced. As a result, the mass of the hydrorefining catalyst that can be packed into a hydrorefining reactor is reduced, and the catalytic performance of the entire reactor is reduced. By keeping the volume PV-p of pores with a pore diameter of 20 Å or more and 600 Å or less within the above range, the activity of a hydrorefining catalyst using γ-alumina as a carrier is improved, and the catalytic performance of the entire hydrorefining reactor is improved.

[0026] The pH at which the isoelectric point (IEP) of pseudo-boehmite in water (a dilute aqueous solution of pseudo-boehmite) is 8.8 or higher, preferably 9.0 or higher. The pH at which the isoelectric point of pseudo-boehmite in water is 8.8 to 10.4, 9.0 to 10.0, or 9.1 to 9.7 may be used. The pH of water containing pseudo-boehmite in the form of a powder (multiple particles) is continuously increased while the zeta potential of the pseudo-boehmite and the pH of the water are continuously measured, thereby determining the pH at which the zeta potential (surface potential of the particles) of the pseudo-boehmite becomes zero (i.e., the isoelectric point). The inventors speculate that the more the (001) plane of pseudo-boehmite is exposed, the higher the average potential (zeta potential) of the pseudo-boehmite surface and the higher the pH at which the isoelectric point is. In other words, the pH at which the isoelectric point of pseudo-boehmite in water is an indicator of the degree of exposure of the (001) plane of pseudo-boehmite. Since the (001) plane of γ-alumina originates from the (001) plane of pseudo-boehmite, which is the raw material for γ-alumina, the pH indicating the isoelectric point of pseudo-boehmite in water is also an indicator of the degree of exposure of the (001) plane of γ-alumina constituting the support of the hydrorefining catalyst. When the pH indicating the isoelectric point of pseudo-boehmite in water is within the above range, the (001) plane of γ-alumina constituting the support of the hydrorefining catalyst is sufficiently exposed, making it easy to obtain excellent catalytic activity due to the (001) plane of γ-alumina. When the pH indicating the isoelectric point of pseudo-boehmite in water is outside the above range, the (001) plane of γ-alumina is not sufficiently exposed.

[0027] The pseudo-boehmite may contain at least one Group 4 element. The Group 4 element may be at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), and hafnium (Hf). The total content of the Group 4 elements in the pseudo-boehmite may be 0.01% by mass or more and 1.0% by mass or less, preferably 0.05% by mass or more and 0.5% by mass or less, and more preferably 0.1% by mass or more and 0.3% by mass or less. The Group 4 element is derived from a masking reagent (e.g., a sulfate of a Group 4 element) used in the pseudo-boehmite production method described below. In the pseudo-boehmite production process (the third step described below), the masking reagent covers the (001) plane of the pseudo-boehmite seed crystal. Masking the (001) plane with the masking reagent inhibits stacking of the (001) plane of the pseudo-boehmite (i.e., seed crystal growth in the

[001] direction) and promotes stacking of the (010) plane of the pseudo-boehmite (i.e., seed crystal growth in the

[010] direction). In other words, stacking of lattice planes perpendicular to the (001) plane covered with the masking reagent is promoted. As a result, the (001) plane is more likely to expand in the in-plane direction, resulting in pseudo-boehmite with a fully exposed (001) plane. Since the (001) plane of γ-alumina originates from the (001) plane of pseudo-boehmite, which is the raw material for γ-alumina, the (001) plane of γ-alumina formed from pseudo-boehmite produced using the masking reagent is also fully exposed. As a result, excellent catalytic activity due to the (001) plane of γ-alumina is easily achieved. At least a portion of the Group 4 element derived from the masking reagent remains in the pseudo-boehmite. As the amount of masking reagent used in producing the pseudo-boehmite increases, the content of Group 4 elements in the pseudo-boehmite also increases. When the total content of Group 4 elements in the pseudo-boehmite is 0.01% by mass or more, the masking of the (001) plane by the masking reagent is sufficient, and the area of ​​the exposed (001) plane in the pseudo-boehmite is likely to increase more than the areas of other lattice planes, making it easier to obtain excellent catalytic activity due to the (001) plane of γ-alumina formed from the pseudo-boehmite. When the total content of Group 4 elements in the pseudo-boehmite is too high, it becomes difficult to knead and mold the pseudo-boehmite and to control the pore distribution of the γ-alumina during the process of producing a carrier (γ-alumina) using the pseudo-boehmite.

[0028] The particle size (for example, median diameter) of the pseudo-boehmite may be 10 μm or more and 200 μm or less.

[0029] (Method for Producing Pseudo-Boehmite) A method for producing the pseudo-boehmite according to the present embodiment will be described below. The method for producing pseudo-boehmite according to the present embodiment includes a first step (seed crystal generation step), a second step (pre-masking step) following the first step, a third step (masking) following the second step, and a fourth step (crystal growth step) following the third step. Details of each step are as follows.

[0030] [First Step (Seed Crystal Formation Step)] In the first step, a first aqueous solution containing an aluminum salt and a second aqueous solution containing an aluminate of an alkali metal (Group 1 element) are supplied into a reaction vessel containing heated water. As a result, pseudo-boehmite seed crystals (microcrystals) are formed in the reaction solution contained in the reaction vessel. The reaction solution in the reaction vessel may be referred to as a mixture of the first aqueous solution, the second aqueous solution, and water. Because the first aqueous solution is acidic and the second aqueous solution is basic, the pseudo-boehmite seed crystals precipitate in the reaction solution due to a neutralization reaction between the first aqueous solution and the second aqueous solution. In other words, pseudo-boehmite is formed by the reaction between the aluminum salt and the aluminate of the alkali metal in water. While the first aqueous solution and the second aqueous solution are being supplied to the reaction vessel, the reaction solution in the reaction vessel may be continuously heated. After the supply of the first aqueous solution and the second aqueous solution to the reaction vessel is stopped, the reaction solution in the reaction vessel may be aged by continuing to heat the reaction solution in the reaction vessel. The aging of the reaction solution continues the formation and growth of the seed crystals. However, aging of the reaction solution is not essential. The aluminum salt contained in the first aqueous solution may be at least one compound selected from the group consisting of aluminum sulfate, aluminum chloride, and aluminum nitrate. The aluminate contained in the second aqueous solution may be at least one compound selected from the group consisting of sodium aluminate, potassium aluminate, and lithium aluminate. The concentration of the aluminum salt in the first aqueous solution used in the first step may be 0.1 mol / L or more and 1.0 mol / L or less. The concentration of the aluminate in the second aqueous solution used in the first step may be 0.1 mol / L or more and 1.0 mol / L or less. In the first step, the time for continuing to supply the first aqueous solution and the second aqueous solution to the reaction vessel may be 5 minutes or more and 60 minutes or less, preferably 10 minutes or more and 30 minutes or less. In the first step, the pH of the reaction solution in the reaction vessel may be 3.5 or more and 9.5 or less, preferably 3.5 or more and 5.5 or less. The lower the pH of the reaction solution, the more easily the (001) plane of the seed crystal is exposed. The pH of the reaction solution may be freely adjusted based on the concentrations of the first and second aqueous solutions and the mixing ratio of the first and second aqueous solutions.The temperature of the reaction liquid in the first step may be 50° C. or higher and 75° C. or lower, preferably 60° C. or higher and 75° C. or lower. The temperature of the reaction liquid may be freely adjusted by a heating mechanism (such as a heater) provided in the reaction vessel. The time for which the aging of the reaction liquid in the first step continues may be 0 minute or higher and 30 minutes or lower.

[0031] [Second Step (Pre-Masking)] In the second step after the first step, the pH of the reaction solution is adjusted (and maintained) at 8.5 or higher. In the second step, the pH of the reaction solution may be adjusted (and maintained) at 8.5 or higher and 9.5 or lower, or 9.2 or higher and 9.5 or lower. For example, the pH of the reaction solution may be adjusted to 8.5 or higher by supplying a basic second aqueous solution to the reaction solution. The pH of the reaction solution may be adjusted to 8.5 or higher by supplying a basic pH adjuster to the reaction solution. The pH of the reaction solution may be adjusted to 8.5 or higher by supplying both the second aqueous solution and a pH adjuster to the reaction solution. The pH adjuster may be at least one compound selected from the group consisting of sodium hydroxide (caustic soda), potassium hydroxide, lithium hydroxide, ammonia, and quaternary ammonium hydroxide (such as tetrapropylammonium hydroxide).

[0032] [Third Step (Masking)] In the third step after the second step, a masking reagent is supplied to the reaction solution, and a second aqueous solution is supplied to the reaction solution, thereby adjusting (and maintaining) the pH of the reaction solution at 8.5 or higher. As a result, the masking reagent covers the (001) plane of the pseudo-boehmite seed crystals. The masking reagent is acidic. Therefore, if only the masking reagent were supplied to the reaction solution in the third step, the pH of the reaction solution in the third step would be lower than the lower limit (8.5) of the pH of the reaction solution in the second step. On the other hand, since the second aqueous solution is basic, the pH of the reaction solution increases when the second aqueous solution is supplied to the reaction solution. Therefore, by supplying not only the masking reagent but also the second aqueous solution to the reaction solution, the pH of the reaction solution in the third step can be adjusted to 8.5 or higher. In other words, in the third step, the decrease in pH of the reaction solution due to the masking reagent is offset by the increase in pH of the reaction solution due to the second aqueous solution. In the third step, the pH of the reaction solution may be adjusted (and maintained) to 8.5 or more and 9.5 or less. After the masking reagent is supplied to the reaction solution, the second aqueous solution may be supplied to the reaction solution. The masking reagent and the second aqueous solution may be supplied to the reaction solution simultaneously.

[0033] In the third step, an aqueous solution of a masking reagent may be supplied to the reaction solution. The concentration of the masking reagent in the aqueous solution may be 0.01 mol / L or more and 1.0 mol / L or less. The concentration of the aluminate in the second aqueous solution used in the third step may be 0.1 mol / L or more and 1.0 mol / L or less. ２ O ３ The amount of masking reagent added per 100 parts by mass of pseudo-boehmite (seed crystals), converted into the mass of ammonium hydroxide, may be 0.01 parts by mass or more and 0.3 parts by mass or less. The temperature of the reaction solution in the third step may be room temperature (e.g., (20±15)°C) or more and 80°C or less. In the third step, it is preferable to uniformly and rapidly inject the aqueous solution of the masking reagent into the reaction solution using a nozzle or the like. The time for injecting the aqueous solution of the masking reagent into the reaction solution may be 0.5 minutes or more and 10 minutes or less.

[0034] The masking reagent is at least one compound selected from the group consisting of a salt containing at least one Group 4 element, a surfactant, a glycol, an organic acid, and an organic acid salt. The salt containing at least one Group 4 element may contain at least one Group 4 element selected from the group consisting of titanium (Ti), zirconium (Zr), and hafnium (Hf). The salt containing at least one Group 4 element is polar and therefore easily covers the (001) plane of the pseudo-boehmite seed crystal. For example, the salt containing at least one Group 4 element may be at least one compound selected from the group consisting of sulfates, nitrates, hydrochlorides, and organic acid salts. For example, the surfactant may be a nonionic surfactant such as poly(oxyethylene) alkyl ether. For example, the glycol may be triethylene glycol. For example, the organic acid may be at least one compound selected from the group consisting of adipic acid, long-chain unsaturated fatty acids (e.g., oleic acid), and oxalic acid. For example, the organic acid salt may be at least one compound selected from the group consisting of adipates, long-chain unsaturated fatty acid salts (e.g., oleates), and oxalates. The organic acid salt may be a salt containing at least one alkali metal (Group 1 element). For example, the organic acid salt may contain at least one alkali metal (Group 1 element) selected from the group consisting of sodium (Na), potassium (K), and lithium (Li). Because the (001) plane of pseudo-boehmite is easily exposed, the masking reagent is preferably at least one compound selected from the group consisting of sulfates, nitrates, hydrochlorides, and organic acid salts, and more preferably at least one compound selected from the group consisting of sulfates and hydrochlorides. Like organic acids, the masking reagent preferably disappears during the carrier production process (calcination of the pseudo-boehmite-containing molded body) described below. In other words, it is preferable that elements derived from the masking reagent do not remain in the carrier or the hydrotreating catalyst. However, there is no problem with the Group 4 element (titanium, etc.) derived from the masking reagent remaining in the support and the hydrotreating catalyst, because although the Group 4 element derived from the masking reagent is likely to remain in the support and the hydrotreating catalyst, the catalytic activity is unlikely to be deteriorated by the Group 4 element derived from the masking reagent.

[0035] [Fourth Step (Crystal Growth Step)] In the fourth step after the third step, the first and second aqueous solutions are supplied to the reaction solution, and the reaction solution is maintained basic, thereby growing seed crystals in the reaction solution. As a result of masking the (001) plane with the masking reagent in the third step, stacking of the (001) plane of the pseudo-boehmite (i.e., growth of the seed crystal in the

[001] direction) is suppressed in the fourth step, and stacking of the (010) plane of the pseudo-boehmite (growth of the seed crystal in the

[010] direction) is promoted. In other words, stacking of the (010) plane perpendicular to the (001) plane covered with the masking reagent is promoted. As a result, the (001) plane easily expands in the in-plane direction, resulting in pseudo-boehmite with a fully exposed (001) plane. The concentration of the aluminum salt in the first aqueous solution used in the fourth step may be 0.1 mol / L or more and 1.0 mol / L or less. The concentration of the aluminate in the second aqueous solution used in the fourth step may be 0.1 mol / L or more and 1.0 mol / L or less. In the fourth step, the time for supplying the first aqueous solution and the second aqueous solution to the reaction solution may be 5 minutes or more and 120 minutes or less, preferably 10 minutes or more and 30 minutes or less. In the fourth step, the pH of the reaction solution may be adjusted to 8.0 or more and 9.8 or less, preferably 8.5 or more and 9.5 or less. The pH of the reaction solution may be freely adjusted based on the respective concentrations of the first aqueous solution and the second aqueous solution and the mixing ratio of the first aqueous solution and the second aqueous solution. The temperature of the reaction solution in the fourth step may be 50°C or more and 75°C or less, preferably 60°C or more and 75°C or less. As the temperature of the reaction solution increases in the fourth step, the crystal growth rate of pseudo-boehmite accelerates. Due to the acceleration of the crystal growth rate in the fourth step, the fifth step (aging step) described below may be omitted or shortened.

[0036] The method for producing pseudo-boehmite according to this embodiment may further include a fifth step (aging step) and a sixth step (recovery step) in addition to the four steps described above. However, the fifth step is not essential. Details of the fifth step and the sixth step are as follows.

[0037] [Fifth Step (Aging Step)] The fifth step may be performed after the fourth step (Crystal Growth Step). In the fifth step, the supply of the first aqueous solution and the second aqueous solution to the reaction solution is terminated, and the reaction solution is stirred while maintaining the temperature of the reaction solution at approximately the same temperature as the temperature of the reaction solution in the fourth step. As a result, the crystal growth of pseudo-boehmite in the reaction solution further progresses, and the particle size of the pseudo-boehmite crystal particles in the reaction solution increases. Furthermore, Ostwald ripening is likely to occur during the fifth step. The Ostwald ripening phenomenon is a phenomenon in which crystal particles with relatively high surface energy (mainly crystal particles with relatively small particle size) in the reaction solution dissolve and precipitate and deposit on the surfaces of crystal particles with relatively low surface energy (crystal particles with relatively large particle size), growing into larger crystal particles, thereby minimizing the surface energy of the crystal particles and resulting in a uniform crystal particle size. In other words, the particle size distribution of the pseudo-boehmite crystal particles in the reaction solution becomes sharper through the fifth step. Due to the increase and uniformity of the particle size of the pseudo-boehmite crystal particles in the fifth step, the pseudo-boehmite crystal particles can be easily recovered from the reaction solution by filtration, and can be easily washed and dried. In other words, the fifth step reduces fine crystal particles that are difficult to recover during the filtration, washing, and drying processes, thereby improving the yield of pseudo-boehmite. The temperature of the reaction solution in the fifth step may be within ±5°C of the temperature of the reaction solution in the fourth step. It is not necessary to maintain the pH of the reaction solution in the fourth step. The duration of the fifth step (aging time) may be 5 minutes or more and 120 minutes or less, preferably 20 minutes or more and 60 minutes or less. When the time for supplying the first aqueous solution and the second aqueous solution to the reaction solution in the fourth step (crystal growth step) is 30 minutes or less, it is preferable to carry out the fifth step.

[0038] [Sixth Step (Recovery Step)] The sixth step is performed after the fourth step (crystal growth step) or the fifth step (aging step). In the sixth step, the pseudo-boehmite (numerous crystalline particles of pseudo-boehmite) in the reaction solution is recovered from the reaction solution. For example, the pseudo-boehmite may be recovered by filtering the reaction solution. The recovered pseudo-boehmite (powder) may be washed. A belt conveyor-type or filter press-type filtering and washing device may be used to filter the reaction solution and wash the pseudo-boehmite. Neutral or weakly acidic washing water may be used to wash the pseudo-boehmite. By washing the pseudo-boehmite, catalytic poisons (e.g., sodium and sulfate ions) derived from the raw materials for the pseudo-boehmite are removed. The washed pseudo-boehmite may be dried. The drying temperature for the pseudo-boehmite may be 80°C or higher and 250°C or lower, preferably 120°C or higher and 150°C or lower. A spray dryer, a flash dryer, or the like may be used to dry the pseudo-boehmite. The particle size (for example, median diameter) of the pseudo-boehmite recovered in the sixth step may be 10 μm or more and 200 μm or less.

[0039] (Methods for producing the carrier and the hydrotreating catalyst) In the methods for producing the carrier and the hydrotreating catalyst according to this embodiment, the pseudo-boehmite according to this embodiment described above is used as a raw material. The method for producing the carrier according to this embodiment includes the steps of kneading raw materials containing the pseudo-boehmite and a peptizer to form a dough (step A), forming a compact from the dough (step B), and calcining the compact to obtain a carrier (step C). The peptizer may be referred to as a deflocculant. The method for producing the hydrotreating catalyst according to this embodiment includes the method for producing the carrier according to this embodiment. The method for producing the hydrotreating catalyst according to this embodiment further includes the step of supporting an active component on a carrier (step D).

[0040] The deflocculating agent used in step A may be an acid or a base. The acid used as the deflocculating agent may be at least one compound selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, formic acid, acetic acid, citric acid, and oxalic acid. The base used as the deflocculating agent may be at least one compound selected from the group consisting of ammonia, quaternary ammonium hydroxide (e.g., tetrapropylammonium hydroxide), sodium hydroxide, potassium hydroxide, and alkali metal aluminates (e.g., sodium aluminate). To improve the moldability of the dough, the dough raw materials may further contain, in addition to the pseudo-boehmite and the deflocculating agent, at least one liquid selected from the group consisting of water, alcohol, and ketone. To improve the moldability of the dough, the dough raw materials may further contain a molding aid in addition to the pseudo-boehmite and the deflocculating agent. The molding aid may be an organic compound such as a water-soluble cellulose ether. Components of the dough raw materials other than the pseudo-boehmite evaporate or decompose during step C (firing the molded body), and therefore are unlikely to remain on the carrier.

[0041] In step B, a molded body may be formed from the dough using a molding device such as a plunger extruder or a screw extruder. The molded body may be dried by heating. The drying temperature for the molded body may be 100°C or higher and 200°C or lower.

[0042] The firing temperature of the molded body in step C may be 400°C or higher and 900°C or lower.

[0043] The support produced by the above method may contain porous γ-alumina. The support may consist solely of porous γ-alumina. The shape of the support may be a sphere, a cylinder, a cylindrical column, a prism, or a column having a trilobal or quadruple-leaf cross section. For example, the maximum diameter of the cross section of the support (a cross section perpendicular to the length direction in the case of a column or cylinder) may be 0.5 mm or more and 6 mm or less. The length of the support may be adjusted as desired, taking into account handleability.

[0044] The volume PV-s of pores in the support having a pore diameter of 20 Å or more and 600 Å or less may be 0.60 ml / g or more and 0.96 ml / g or less, 0.608 ml / g or more and 0.812 ml / g or less, or 0.608 ml / g or more and 0.785 ml / g or less. If the pore volume PV-s is too small, the activity and life of the hydrorefining catalyst produced from the support will be significantly reduced. In other words, if the pore volume PV-s is too small, the hydrorefining catalyst will be easily deteriorated due to deposition and accumulation of metal components and carbon (coke) inside and outside the hydrorefining catalyst during the demetalization reaction using the hydrorefining catalyst, and the differential pressure in the reactor packed with the hydrorefining catalyst will increase. If the pore volume PV-s is too large, the bulk density of the hydrorefining catalyst will be unnecessarily reduced. As a result, the mass of the hydrotreating catalyst that can be packed into the hydrotreating reactor decreases, and the catalytic performance of the reactor as a whole decreases.

[0045] The method for attaching the active ingredient to the support in step D may be an impregnation method, a pore-filling method, a heat impregnation method, a vacuum impregnation method, a dipping method, or the like. The support to which the active ingredient is attached may be dried by heating. The drying temperature of the support may be 100°C or higher and 200°C or lower. The dried support may be further heated at a temperature of 400°C or higher and 600°C or lower, thereby supporting the active ingredient on the support.

[0046] The active component may include at least one Group 6 element. That is, the hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment may include at least one Group 6 element as the active component. The active component may include at least one element selected from Groups 8 to 10. That is, the hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment may include at least one element selected from Groups 8 to 10 as the active component. The active component may include at least one Group 6 element and at least one element selected from Groups 8 to 10. The active component may include phosphorus (P). That is, the hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment may include phosphorus. The active component may include at least one Group 6 element, at least one element selected from Groups 8 to 10, and phosphorus (P). That is, the hydrotreating catalyst produced from the pseudo-boehmite according to this embodiment may include at least one Group 6 element, at least one element selected from Groups 8 to 10, and phosphorus as the active components. The Group 6 element contained in the active component is preferably at least one element selected from the group consisting of chromium (Cr), molybdenum (Mo), and tungsten (W). The Group 8 to 10 element contained in the active component is preferably at least one element selected from the group consisting of cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), and platinum (Pt). More preferably, the active component contains at least one element selected from the group consisting of chromium, molybdenum, and tungsten, and at least one element selected from the group consisting of cobalt and nickel. The total content of the Group 6 element and the Group 8 to 10 elements in the hydrorefining catalyst may be 0.1% by mass or more and 15% by mass or less. The phosphorus content in the hydrorefining catalyst may be 0% by mass or more and 3% by mass or less.

[0047] The hydrorefining catalyst produced by the above method may be used as a catalyst for the desulfurization and denitrification of petroleum fractions (such as vacuum gas oil) having a boiling point of 200 to 360°C. The hydrorefining catalyst may be used as a catalyst for the desulfurization of petroleum fractions (such as atmospheric residue) having a 50% distillation temperature of 450°C or higher. The hydrorefining catalyst may be used as a catalyst for the desulfurization, demetallization, and hydrocracking of heavy oils (such as vacuum residue). With the hydrorefining catalyst produced from pseudo-boehmite according to the embodiment, the support structure and support form of the active component (active metal) are controlled and maintained, and high activity is maintained for a long period of time.

[0048] The pore volume PV-h of pores in the hydrorefining catalyst having a pore diameter of 20 Å or more and 600 Å or less may be 0.50 ml / g or more and 0.80 ml / g or less, or 0.50 ml / g or more and 0.65 ml / g or less. If the pore volume PV-h is too small, the activity and life of the hydrorefining catalyst will be significantly reduced. In other words, if the pore volume PV-h is too small, the hydrorefining catalyst will be easily deteriorated due to the deposition and accumulation of metal components and carbon (coke) inside and outside the hydrorefining catalyst during the demetalization reaction using the hydrorefining catalyst, and the differential pressure in the reactor packed with the hydrorefining catalyst will increase. If the pore volume PV-h is too large, the bulk density of the hydrorefining catalyst will be unnecessarily reduced. As a result, the mass of the hydrorefining catalyst that can be packed into the hydrorefining reaction column will decrease, and the catalytic performance of the reaction column as a whole will be reduced.

[0049] The compositions of the pseudo-boehmite, the support, and the hydrotreating catalyst may be identified by at least one analytical method such as inductively coupled plasma (ICP) emission spectroscopy and X-ray fluorescence (XRF) analysis.

[0050] The present invention is not necessarily limited to the above-described embodiments. Various modifications of the present invention are possible without departing from the spirit of the present invention, and these modifications are also included in the present invention.

[0051] The present invention will be described in detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

[0052] Example 1 Production of Pseudo-Boehmite [First Step (Seed Crystal Generation Step)] In the first step, 500 ml of water was placed in a beaker (reaction vessel). The volume of the beaker was 1500 ml. The water in the beaker was continuously heated to maintain the water temperature at 60°C. After the water was placed in the beaker, a first aqueous solution was supplied into the beaker at a flow rate of 14.0 ml / min, and a second aqueous solution was also supplied into the beaker. The first aqueous solution was an aqueous solution of aluminum sulfate, and the concentration of aluminum sulfate in the first aqueous solution was 0.58 mol / L. The second aqueous solution was an aqueous solution of sodium aluminate, and the concentration of sodium aluminate in the second aqueous solution was 0.68 mol / L. The flow rate of the second aqueous solution was finely adjusted so that the pH of the reaction solution (a mixture of water, the first aqueous solution, and the second aqueous solution) in the beaker was maintained at 5.0. As the first aqueous solution and the second aqueous solution were supplied to the beaker, numerous seed crystals were generated in the reaction solution and precipitated. Supply of the first aqueous solution and the second aqueous solution to the beaker was completed 20 minutes after the start of the supply. After the supply of the first aqueous solution and the second aqueous solution to the beaker was completed, the reaction solution was aged for 10 minutes while being stirred. From the start of supply of the first aqueous solution and the second aqueous solution to the beaker until the aging of the reaction solution was completed, the temperature of the reaction solution in the beaker was maintained at 60°C.

[0053] [Second Step (Pre-Masking)] During the following second, third, and fourth steps, the reaction solution in the beaker was continuously heated to maintain the temperature of the reaction solution in the beaker at 75°C. In the second step following the first step, after the temperature of the reaction solution in the beaker reached 75°C, the second aqueous solution was supplied into the beaker at a flow rate of 9.2 ml / min for about 2 minutes, thereby adjusting the pH of the reaction solution in the beaker to 9.5. The concentration of sodium aluminate in the second aqueous solution used in the second step was also 0.68 mol / L.

[0054] [Third Step (Masking)] In the third step following the second step, an aqueous solution of a masking reagent (reagent solution) was supplied to the reaction solution in the beaker. A total of 50 ml of the reagent solution was supplied to the reaction solution over 5 minutes. The masking reagent contained in the reagent solution was titanium sulfate. The content of the masking reagent in the reagent solution was 2% by mass. After the reagent solution was supplied to the reaction solution, the second aqueous solution was supplied to the beaker at a flow rate of 9.2 ml / min for approximately 0.5 minutes, thereby adjusting the pH of the reaction solution in the beaker to 9.5. The concentration of sodium aluminate in the second aqueous solution used in the third step was also 0.68 mol / L.

[0055] [Fourth Step (Crystal Growth Step)] In the fourth step following the third step, the first aqueous solution was supplied to the beaker at a flow rate of approximately 12.5 ml / min, and the second aqueous solution was supplied to the beaker at a flow rate of 9.2 ml / min, thereby maintaining the pH of the reaction solution at 9.5. The supply of the first aqueous solution and the second aqueous solution to the beaker was completed 5 minutes after the start of the supply. The concentration of aluminum sulfate in the first aqueous solution used in the fourth step was also 0.58 mol / L. The concentration of sodium aluminate in the second aqueous solution used in the fourth step was also 0.68 mol / L.

[0056] [Fifth Step (Aging Step)] In the fifth step following the fourth step, the reaction solution in the beaker was aged at 75° C. for 10 minutes without supplying the first aqueous solution and the second aqueous solution into the beaker.

[0057] [Sixth Step (Recovery Step)] In the sixth step following the fifth step, the solid content was recovered from the reaction solution by filtering the reaction solution in the beaker. After washing the solid content, the solid content was dried overnight at 130°C using a hot air dryer to obtain the powder of Example 1.

[0058] <Powder Analysis> The XRD pattern of the powder of Example 1 was measured. A multipurpose X-ray diffractometer (SmartLab) manufactured by Rigaku Corporation was used to measure the XRD pattern. The incident X-ray used to measure the XRD pattern was CuKα1 radiation. As a result of analyzing the XRD pattern, it was confirmed that the powder of Example 1 was pseudo-boehmite. The full width at half maximum β of the diffracted X-ray peak of the (020) plane of pseudo-boehmite was ０２０The full width at half maximum β of the diffracted X-ray peak of the (120) plane of pseudo-boehmite is shown in Table 1 below. １２０ is shown in Table 1 below. Based on the measured XRD pattern, D is calculated from the Scherrer equation. ０２０ and D １２０ was calculated. ０２０ , D １２０ , and D ０２０ / D １２０ is shown in Table 1 below. Scherrer's formula, D ０２０ , and D １２０ The details of each are as described above.

[0059] The pH, which indicates the isoelectric point of the pseudo-boehmite in water (a dilute aqueous solution of pseudo-boehmite), was measured. A Zetasizer Nano Series ZS manufactured by Malvern Panalytical Ltd. was used as the device for measuring the pH, which indicates the isoelectric point (zeta potential measuring device). The pH, which indicates the isoelectric point of the pseudo-boehmite of Example 1, is shown in Table 1 below.

[0060] The pore size distribution of the pseudo-boehmite of Example 1 was measured by a nitrogen adsorption method. The volume PV-p of pores in the pseudo-boehmite having a pore size of 20 Å or more and 600 Å or less was determined from the pore size distribution. The volume PV-p of Example 1 is shown in Table 1 below.

[0061] The titanium content in the pseudo-boehmite was measured by ICP emission spectroscopy. The titanium content in the pseudo-boehmite of Example 1 was 0.3 mass%. The titanium content in the pseudo-boehmite of Comparative Example 4, which will be described later, was also 0.3 mass%.

[0062] <Production of Carrier> Raw materials consisting of the pseudoboehmite (powder) of Example 1 and a deflocculant (aqueous solution of dilute nitric acid with a concentration of 3% by mass) were kneaded in a kneader to obtain a dough. The solid content of the dough was approximately 50% by mass. A large number of molded bodies were formed from the dough by extrusion molding using a twin-arm extruder. The molded bodies had a cylindrical or four-lobe shape. The molded bodies were dried at 130°C. The dried molded bodies were calcined at 600°C for 1 hour to obtain the carrier of Example 1 made of γ-alumina.

[0063] The pore size distribution of the support of Example 1 was measured by nitrogen adsorption. The volume PV-s of pores in the support having a pore size of 20 Å or more and 600 Å or less was determined from the pore size distribution. The volume PV-s of Example 1 is shown in Table 1 below.

[0064] <Production of Hydrotreating Catalyst> An aqueous solution (raw material solution) containing molybdate, nickel salt, and phosphoric acid as active components was prepared. The raw material solution was impregnated into the support of Example 1 by a one-stage or two-stage spray method. After impregnation with the raw material solution, the support was dried at 130°C for 20 hours using a dryer. After drying, the support was calcined at 450°C for 25 minutes in an air stream to obtain the hydrotreating catalyst of Example 1. A rotary kiln was used to calcinate the support. The molybdenum content in the hydrotreating catalyst was adjusted to 8.0% by mass. The nickel content in the hydrotreating catalyst was adjusted to 2.2% by mass. The phosphorus content in the hydrotreating catalyst was adjusted to 1.0% by mass.

[0065] The pore size distribution of the hydrotreating catalyst of Example 1 was measured by nitrogen adsorption. The volume PV-h of pores in the hydrotreating catalyst with a pore size of 20 Å or more and 600 Å or less was determined from the pore size distribution. The volume PV-h of Example 1 is shown in Table 1 below.

[0066] <Evaluation of Catalytic Activity> The activity of the hydrorefining catalyst of Example 1 was evaluated by the following reaction steps.

[0067] The hydrotreating catalyst of Example 1 was packed into a reactor. In the reaction step, Middle Eastern feedstock oil was brought into contact with the hydrotreating catalyst in the reactor to which hydrogen gas was supplied. The reaction conditions were as follows: partial pressure of hydrogen gas in the reactor: 14.0 MPa; liquid hourly space velocity (LHSV): 1.0 h －１ Hydrogen / oil ratio: 970 Nm ３ / m ３

[0068] The properties of the Middle Eastern feedstock oil were as follows: Sulfur content C Ｓ０ Nitrogen content: 3.371 mass% Vanadium (V) content C: 1600 mass ppm Ｖ０: 30.0 mass ppm Nickel (Ni) content C Ｎｉ０ : 10.4 mass ppm Density at 15 ° C: 0.9669 g / mL Density at 70 ° C: 0.9291 g / mL Kinematic viscosity at 50 ° C (calculated value): 348.0 mm ２ / sec Kinematic viscosity at 100 ° C: 35.2 mm ２ / sec Kinematic viscosity at 120 ° C: 19.3 mm ２ / sec Residual carbon content: 8.93 mass% Heptane insoluble content: 4.44 mass%

[0069] The analytical methods for the above properties of the Middle Eastern feedstock oil were as follows: Sulfur content: JIS K2541 "Crude oil and petroleum products - Determination of sulfur content" Vanadium and nickel content: JIS K0116 "General rules for optical emission spectroscopy"

[0070] Four reaction steps were carried out individually, with the reaction temperature T being 360°C, 375°C, 390°C, or 400°C. The sulfur content C in the product oil (hydrocarbon oil) obtained in the reaction step at each reaction temperature T Ｓ１ was measured. Ｓ１ is the sulfur content C of the above-mentioned Middle Eastern feedstock oil. Ｓ０ The density of the Middle Eastern feedstock oil at each reaction temperature T is expressed as d0. Based on the second-order reaction rate equation (Equation 3) below, LHSV, d0, C Ｓ０ and C Ｓ１ From the above, the measured value of the reaction rate constant k at each reaction temperature T ＳＭ was calculated. ＳＭ The natural logarithm of lnk ＳＭ The natural logarithm lnk ＳＭ The relationship between lnk and the reaction temperature T (unit: K) was considered to be the following linear equation (Equation 2A), and an Arrhenius plot was created. Specifically, first, lnk ＳＭ and 1000 / T (unit: K －１ ) was plotted. Then, the plotted lnk ＳＭ From 1000 / T and 1000 / T, a regression line expressed by the following linear equation (Equation 2A) was obtained by the least squares method. On the obtained regression line, the estimated value k of the reaction rate constant at 390°C was ＳＰThe performance value of the reference catalyst, k ＳＰ０ (known standard value), k ＳＰ０ k in Example 1 ＳＰ Relative value 100 × k ＳＰ / k ＳＰ０ (unit: %) was calculated. ＳＰ / k ＳＰ０ is expressed as the relative HDS activity. The larger the value of the relative HDS activity, the higher the desulfurization activity. The target value of the relative HDS activity is 90% or more. k at each reaction temperature T in Example 1 ＳＭ The relative HDS activity of Example 1 is shown in Table 2 below. ＳＭ =-(E / R)×(1 / T)+lnA (2A) k ＳＭ : Desulfurization reaction rate constant E: Activation energy R: Gas constant A: Frequency factor

[0071] The vanadium content C in the product oil obtained in the above reaction step at each reaction temperature T Ｖ１ and nickel content C Ｎｉ１ Each was measured. Ｖ１ and C Ｎｉ１ is the vanadium content C in the Middle Eastern feedstock oil. Ｖ０ and nickel content C Ｎｉ０ Based on the first-order reaction rate equation (Equation 4) below, LHSV, C Ｖ０ and C Ｎｉ０ , and C Ｖ１ and C Ｎｉ１ From the above, the measured value of the reaction rate constant k at each reaction temperature T ＭＭ was calculated. ＭＭ The natural logarithm of lnk ＭＭ The natural logarithm lnk ＭＭ The relationship between lnk and reaction temperature T (unit: K) was considered to be the following linear equation (2B), and an Arrhenius plot was created. Specifically, first, lnk ＭＭ and 1000 / T (unit: K －１ ) was plotted. Then, the plotted lnk ＭＭFrom 1000 / T and 1000 / T, a regression line expressed by the following linear equation (2B) was obtained by the least squares method. On the obtained regression line, the estimated value k of the reaction rate constant at 390°C was ＭＰ The performance value of the reference catalyst, k ＭＰ０ (known standard value), k ＭＰ０ k in Example 1 ＭＰ Relative value 100 × k ＭＰ / k ＭＰ０ (unit: %) was calculated. ＭＰ / k ＭＰ０ is expressed as the relative HDM activity. The higher the value of the relative HDM activity, the higher the demetalization activity. The target value of the relative HDM activity is 90% or more. k at each reaction temperature T in Example 1 ＭＭ The relative HDM activity of Example 1 is shown in Table 2 below. ＭＭ =-(E / R)×(1 / T)+lnA (2B) k ＭＭ : Demetallization reaction rate constant E: Activation energy R: Gas constant A: Frequency factor k ＭＭ =LHSV×ln{(C Ｖ０ +C Ｎｉ０ ) / (C Ｖ１ +C Ｎｉ１ ) (4)

[0072] Examples 2 to 6 In Example 2, adipic acid was used as the masking reagent instead of titanium sulfate. In Example 3, Tergitol Type-15-S-7 manufactured by Sigma-Aldrich Co. LLC was used as the masking reagent instead of titanium sulfate. Tergitol Type-15-S-7 is a poly(oxyethylene) alkyl ether and a nonionic surfactant. In Example 4, sodium oleate (a type of long-chain unsaturated fatty acid salt) was used as the masking reagent instead of titanium sulfate. In Example 5, triethylene glycol (TEG) was used as the masking reagent instead of titanium sulfate. In Example 6, oxalic acid was used as the masking reagent instead of titanium sulfate. The pseudo-boehmite, support, and hydrotreating catalyst of Examples 2 to 6 were prepared in the same manner as in Example 1, except for the above-mentioned points. Measurements, analyses, and evaluations were carried out on the pseudo-boehmite, carrier, and hydrotreating catalyst for each of Examples 2 to 6 in the same manner as in Example 1. The results of the measurements, analyses, and evaluations for each of Examples 2 to 6 are shown in Tables 1 and 2 below.

[0073] Examples 7 to 9 In Examples 7 to 9, a cylindrical neutralization and settling tank with a diameter of approximately 2 m was used as the reaction vessel instead of the beaker. In the first step (seed crystal generation step) of each of Examples 7 to 9, ion-exchanged water was added to the reaction vessel until the water level reached approximately 50 cm above the bottom of the reaction vessel. In the first step (seed crystal generation step) of each of Examples 7 to 9, after ion-exchanged water was added to the reaction vessel, a first aqueous solution (aqueous solution of aluminum sulfate) was supplied to the reaction vessel at a feed rate of approximately 10 L / min, and a second aqueous solution (aqueous solution of sodium aluminate) was supplied to the reaction vessel. In the first step of each of Examples 7 and 8, the feed rate of the second aqueous solution was finely adjusted so that the pH of the reaction solution in the reaction vessel was maintained at approximately 5.0. In the first step of Example 9, the feed rate of the second aqueous solution was finely adjusted so that the pH of the reaction solution in the reaction vessel was maintained at approximately 5.5. In the cases of Examples 7 and 8, the temperature of the reaction solution in the reaction vessel was maintained at 70° C. by continuously heating the reaction solution in the reaction vessel during the second step (pre-masking step), the third step (masking step), and the fourth step (crystal growth step). In the case of Example 9, the temperature of the reaction solution in the reaction vessel was maintained at 65° C. by continuously heating the reaction solution in the reaction vessel during the second step (pre-masking step), the third step (masking), and the fourth step (crystal growth step).

[0074] In the second step (before masking) of Example 7, after the temperature of the reaction solution in the reaction vessel reached 70°C, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a flow rate of about 5 L / min for about 5 minutes, thereby adjusting the pH of the reaction solution in the reaction vessel to 9.5. In the second step (before masking) of Example 8, after the temperature of the reaction solution in the reaction vessel reached 70°C, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a flow rate of about 5 L / min for about 3 minutes, thereby adjusting the pH of the reaction solution in the reaction vessel to 9.2. In the second step (before masking) of Example 9, after the temperature of the reaction solution in the reaction vessel reached 65°C, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a flow rate of about 5 L / min for about 3 minutes, thereby adjusting the pH of the reaction solution in the reaction vessel to 9.2.

[0075] In the third step (masking) of Example 7, 40 L of reagent solution was supplied to the reaction solution over approximately 5 minutes. After the reagent solution was supplied to the reaction solution, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a flow rate of approximately 5 L / min for approximately 1 minute, thereby adjusting the pH of the reaction solution in the reaction vessel to 9.5. In the third step (masking) of Example 8, 40 L of reagent solution was supplied to the reaction solution over approximately 5 minutes. After the reagent solution was supplied to the reaction solution, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a flow rate of approximately 5 L / min for approximately 1 minute, thereby adjusting the pH of the reaction solution in the reaction vessel to 9.2. In the third step (masking) of Example 9, 40 L of reagent solution was supplied to the reaction solution over approximately 5 minutes. After the reagent solution was supplied to the reaction solution, the pH of the reaction solution in the reaction vessel was adjusted to 9.2 by supplying a second aqueous solution (aqueous solution of sodium aluminate) into the reaction vessel at a liquid supply rate of about 5 L / min for about 1 minute.

[0076] In the fourth step (crystal growth step) of Example 7, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a liquid feed rate of approximately 5 L / min, and the first aqueous solution (aqueous solution of aluminum sulfate) was also supplied into the reaction vessel, thereby maintaining the pH of the reaction solution at 9.5. The supply of the first aqueous solution and the second aqueous solution into the reaction vessel was completed 5 minutes after the start of the liquid feed. In the fourth step (crystal growth step) of Example 8, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a liquid feed rate of approximately 5 L / min, and the first aqueous solution (aqueous solution of aluminum sulfate) was also supplied into the reaction vessel, thereby maintaining the pH of the reaction solution at 9.2. The supply of the first aqueous solution and the second aqueous solution into the reaction vessel was completed 5 minutes after the start of the liquid feed. In the fourth step (crystal growth step) of Example 9, the second aqueous solution (aqueous solution of sodium aluminate) was supplied into the reaction vessel at a liquid supply rate of about 5 L / min, and the first aqueous solution (aqueous solution of aluminum sulfate) was also supplied into the reaction vessel, thereby maintaining the pH of the reaction solution at 9.2. The supply of the first aqueous solution and the second aqueous solution into the reaction vessel was completed in 1 minute from the start of the liquid supply.

[0077] In the fifth step (aging step) of each of Examples 7 and 8, the reaction solution in the reaction vessel was aged for 10 minutes at 70° C. without supplying the first aqueous solution and the second aqueous solution into the reaction vessel. In the fifth step (aging step) of Example 9, the reaction solution in the reaction vessel was aged for 10 minutes at 65° C. without supplying the first aqueous solution and the second aqueous solution into the reaction vessel.

[0078] Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of each of Examples 7 to 9 were prepared in the same manner as in Example 1. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of each of Examples 7 to 9 were carried out in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of each of Examples 7 to 9 are shown in Tables 1 and 2 below.

[0079] Comparative Example 1 In Comparative Example 1, the second step (pre-masking step), the third step (masking), and the fourth step (crystal growth step) were not performed. That is, in the production of pseudo-boehmite in Comparative Example 1, the fifth step (aging step) was performed following the first step (seed crystal generation step). In the fifth step of Comparative Example 1, the reaction solution in the beaker was aged at 60°C for 30 minutes. Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 1 were prepared in the same manner as in Example 1. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 1 were performed in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of Comparative Example 1 are shown in Tables 1 and 2 below.

[0080] (Comparative Example 2) In the first step of Comparative Example 2, after the water was poured into the beaker, the water temperature in the beaker was maintained at 63°C until just before the second step. In Comparative Example 2, the third step (masking) was not performed. That is, in the production of pseudo-boehmite in Comparative Example 2, the second step (pre-masking step) was followed by the fourth step (crystal growth step). In the fifth step of Comparative Example 2, the reaction solution in the beaker was aged for 30 minutes. Except for the above, the pseudo-boehmite of Comparative Example 2 was produced in the same manner as in Example 1. Measurements and analyses on the pseudo-boehmite of Comparative Example 2 were carried out in the same manner as in Example 1. The results of the measurements and analyses of Comparative Example 2 are shown in Tables 1 and 2 below.

[0081] Comparative Example 3 In the first step of Comparative Example 3, the pH of the reaction solution in the beaker was adjusted and maintained at 9.0. In Comparative Example 3, the second step (pre-masking step), the third step (masking step), and the fourth step (crystal growth step) were not performed. That is, in the production of pseudo-boehmite in Comparative Example 3, the fifth step (aging step) was performed following the first step (seed crystal generation step). In the fifth step of Comparative Example 3, the reaction solution in the beaker was aged at 60°C for 30 minutes. Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 3 were prepared in the same manner as in Example 1. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 3 were performed in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of Comparative Example 3 are shown in Tables 1 and 2 below.

[0082] Comparative Example 4 During the second, third, fourth, and fifth steps of Comparative Example 4, the temperature of the reaction solution in the beaker was maintained at 63°C. During the second, third, and fourth steps of Comparative Example 4, the pH of the reaction solution in the beaker was adjusted to and maintained at 8.0. Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 4 were prepared in the same manner as in Example 1. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 4 were carried out in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of Comparative Example 4 are shown in Tables 1 and 2 below.

[0083] (Comparative Example 5) During the second, third, and fourth steps of Comparative Example 5, the pH of the reaction solution in the beaker was adjusted and maintained at 5.0. Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 5 were prepared in the same manner as in Example 2. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 5 were carried out in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of Comparative Example 5 are shown in Tables 1 and 2 below.

[0084] (Comparative Example 6) During the second, third, and fourth steps of Comparative Example 6, the pH of the reaction solution in the beaker was adjusted and maintained at 5.0. Except for the above, the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 6 were prepared in the same manner as in Example 3. Measurements, analyses, and evaluations of the pseudo-boehmite, support, and hydrotreating catalyst of Comparative Example 6 were carried out in the same manner as in Example 1. The results of the measurements, analyses, and evaluations of Comparative Example 6 are shown in Tables 1 and 2 below.

[0085]

[0086]

[0087] For example, the pseudo-boehmite according to one aspect of the present invention may be used as a raw material for a hydrorefining catalyst or a raw material for a carrier.

[0088] (010)...(010) plane, (020)...(020) plane, (120)...(120) plane, (001)...(001) plane, a...lattice constant in the a-axis direction (

[100] direction), b...lattice constant in the b-axis direction (

[010] direction), c...lattice constant in the c-axis direction (

[001] direction), uc...unit cell of pseudo-boehmite (orthorhombic crystal).

Claims

1. The crystallite diameter D of the pseudo-boehmite in the direction perpendicular to the (020) plane of the pseudo-boehmite ０２０ is 2.0 nm or more and 3.5 nm or less, and the crystallite diameter D of the pseudo-boehmite in a direction perpendicular to the (120) plane of the pseudo-boehmite １２０ is 2.5 nm or more and 4.5 nm or less, D ０２０ / D １２０ is 0.8 or more and 1.3 or less, a volume of pores having a pore diameter of 20 Å or more and 600 Å or less is 0.80 ml / g or more and 1.20 ml / g or less, the volume of the pores is measured by a nitrogen adsorption method, and a pH indicating an isoelectric point of the pseudo-boehmite in water is 8.8 or more.

2. The pseudo-boehmite according to claim 1, comprising at least one Group 4 element, the total content of the Group 4 elements being 0.01% by mass or more and 1.0% by mass or less.

3. A method for producing pseudo-boehmite according to claim 1 or 2, comprising: a first step of supplying a first aqueous solution containing an aluminum salt and a second aqueous solution containing an aluminate of an alkali metal into a reaction vessel containing heated water, thereby generating seed crystals of the pseudo-boehmite in a reaction liquid in the reaction vessel; a second step of adjusting the pH of the reaction liquid to 8.5 or more after the first step; a third step of adjusting the pH of the reaction liquid to 8.5 or more after the second step by supplying a masking reagent to the reaction liquid and supplying the second aqueous solution to the reaction liquid; and a fourth step of growing the seed crystals in the reaction liquid by supplying the first aqueous solution and the second aqueous solution to the reaction liquid and maintaining the reaction liquid basic after the third step, wherein the masking reagent is at least one compound selected from the group consisting of a salt containing at least one Group 4 element, a surfactant, a glycol, an organic acid, and an organic acid salt.

4. The method for producing pseudo-boehmite according to claim 3, wherein the masking reagent is at least one compound selected from the group consisting of sulfates, nitrates, hydrochlorides, and organic acid salts.

5. A method for producing a carrier, comprising the steps of: kneading a raw material containing the pseudo-boehmite according to claim 1 or 2 and a deflocculating agent to form a dough; forming a molded body from the dough; and calcining the molded body to obtain a carrier.

6. A method for producing a hydrorefining catalyst, comprising: a step of forming a dough by kneading a raw material containing the pseudo-boehmite according to claim 1 or 2 and a deflocculating agent; a step of forming a molded body from the dough; a step of obtaining a carrier by firing the molded body; and a step of supporting an active component on the carrier.

7. The method for producing a hydrorefining catalyst according to claim 6, wherein the active component contains at least one Group 6 element and at least one element selected from the Groups 8 to 10 elements.

8. The method for producing a hydrorefining catalyst according to claim 6, wherein the active component contains at least one Group 6 element, at least one element selected from the Groups 8 to 10, and phosphorus.