Silica-alumina powder, method for producing silica-alumina powder, fluid catalytic cracking catalyst and method for producing the same

Abstract

To provide a silica-alumina powder having low coke formation, high gasoline yield, thermal stability and moderate acid density and acid strength for use in a fluid catalytic cracking catalyst and a method for producing the same, and a fluid catalytic cracking catalyst containing such silica-alumina powders.SOLUTION: There is provided a silica-alumina powder and a fluid catalytic cracking catalyst containing such silica-alumina powders with the following characteristics a-f: a. SiO2 is contained in the range of 8 to 20 mass%; b. The crystallite size of boehmite alumina (020) plane by X-ray diffraction is 10 to 50 nm; c. A specific surface area is in the range of 90-230 m2 / g; d. The acid density, which is the amount of acid per specific surface area, is 0.75 to 1.00 μmol / m2; e. The crystal transition temperature from boehmite alumina to gamma alumina in TG-DTA measurement is 470°C or higher; and f. Lewis acid showing a peak near 2230 cm-1 in CO adsorption FT-IR measurement exists.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a silica-alumina powder that is used in a fluid catalytic cracking catalyst and has excellent thermal stability, moderate acid density, and strong Lewis acid strength, and a method for producing the same. More specifically, the present invention relates to a fluid catalytic cracking catalyst containing silica-alumina that has a low coke yield and an excellent gasoline yield, and a method for producing the same. [Background technology]

[0002] Fluid catalytic cracking catalysts used in the fluid catalytic cracking (FCC) process of feedstock (hydrocarbon oil), such as atmospheric distillation residue, contain zeolite, a solid acid. Furthermore, to provide wear resistance when used in a fluidized state, matrix components, such as silica alumina, which has the cracking activity for hydrocarbon oils, are added to the catalyst.

[0003] Silica-alumina generally refers to a mixture or composite oxide of silica and alumina. A mixture of silica and alumina refers to a mixture in which silica and alumina are physically mixed without a chemical bond. In this case, the mixture of silica and alumina has a Lewis acid derived from alumina. On the other hand, a composite oxide of silica and alumina refers to a mixture in which silica and alumina are mixed via a chemical bond. In this case, the composite oxide of silica and alumina has a Bronsted acid derived from its crystal structure.

[0004] Silica-alumina has the characteristic that its acidic properties change depending on whether or not silica and alumina are chemically bonded. Taking advantage of this characteristic, silica-alumina has long been used in various catalytic reactions. It is also produced by various methods.

[0005] For example, Patent Document 1 discloses silica-alumina having a structure in which a silica layer is formed on the surface of alumina as a nucleus, a method for producing the same, and a hydrotreating catalyst.

[0006] Furthermore, Patent Document 2 discloses a catalyst composition for fluid catalytic cracking of heavy oil, which contains, as a catalyst component, silica-alumina having a structure in which an alumina core has silica adhered and bonded to the surface.

[0007] Furthermore, Patent Document 3 discloses a silica-alumina composite oxide having a structure in which a silica layer is formed on the surface of an alumina particle serving as a nucleus, and a method for producing the same.

[0008] Furthermore, Patent Document 4 discloses amorphous silica alumina in which the silica content, specific surface area and acid amount are specified, and a method for producing the same.

[0009] Furthermore, Patent Document 5 discloses a method for producing quasi-crystalline boehmite containing additives in a uniformly dispersed state by combining an inexpensive quasi-crystalline boehmite precursor with additives and aging the mixture.

[0010] Furthermore, Patent Document 6 discloses porous composite particles comprising an aluminum oxide component, such as crystalline boehmite having an average crystallite size of about 20 to about 200 angstroms, and a residue of a crystal size growth inhibitor additive component, such as a silicate or a phosphate, densely dispersed in the aluminum oxide component.

[0011] Furthermore, Non-Patent Documents 1 and 2 confirm the Lewis acid properties of silica alumina by CO adsorption FT-IR. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 06-127931 [Patent Document 2] Japanese Patent Application Publication No. 08-071417 [Patent Document 3] Japanese Patent Application Publication No. 09-255321 [Patent Document 4] Japanese Patent Application Publication No. 11-157828 [Patent Document 5] Special Publication No. 2003-507298 [Patent Document 6] Special Publication No. 2003-517993 [Patent Document 7] U.S. Patent No. 5,569,325 [Non-patent literature]

[0013] [Non-Patent Document 1] Nature, Structure and Strength of the Acidic Sites of Amorphous Silica Alumina: An IR and NMR Study, J. Phys. Chem. B 2006, 110, pp15172-15185. [Non-patent document 2] IR Characterization of Homogeneously Mixed Silica-Alumina Samples and Dealuminated Y Zeolites by Using Pyridine, CO, and Propene Probe Molecules, J. Phys. Chem. C 2013, 117, pp14043-14050. [Non-patent document 3] CA Emeis, J. Catal., 141, 1993, 347-354. Summary of the Invention [Problem to be solved by the invention]

[0014] Silica-alumina, having a solid acidity, is used in various catalytic reactions, such as fluid catalytic cracking catalysts and hydrocracking catalysts. Fluid catalytic cracking, in particular, requires a catalyst with low coke production, and silica-alumina is required to have thermal stability and appropriate acid density and acid strength. However, the techniques disclosed in Patent Documents 1 to 6 do not specify the crystallite size of boehmite as an alumina raw material before adding a silica source when producing silica-alumina, and are therefore unable to control the thermal stability or Lewis acid properties of silica-alumina.

[0015] Non-Patent Documents 1 and 2 confirm the Lewis acid properties of silica-alumina. However, only silica-alumina containing 30 mass% or more of SiO2 exhibits a 2230 cm peak at which a Lewis acid with strong acid strength is observed. -1 A peak around 0.05 has been confirmed. As the silica ratio of silica-alumina increases, the specific surface area increases and the acid content decreases. Therefore, silica-alumina containing 20 mass% or more of SiO2 cannot achieve sufficient acid density when used as a fluid catalytic cracking catalyst.

[0016] The present invention aims to provide a silica-alumina powder that is used in a fluid catalytic cracking catalyst and has excellent thermal stability, a moderate acid density, and a strong Lewis acid strength, a method for producing the same, and a fluid catalytic cracking catalyst that contains the silica-alumina powder and has a low coke yield and an excellent gasoline yield. [Means for solving the problem]

[0017] The silica-alumina powder provided by the present invention has the following characteristics a to f. a. Contains SiO2 in the range of 8 to 20 mass%; b) The crystallite diameter of the boehmite alumina (020) plane determined by X-ray diffraction is 10 to 50 nm; c. The specific surface area of ​​the silica-alumina powder is 90 to 230 m 2 / g, d. The acid density, which is the amount of acid per surface area, is 0.75 to 1.00 μmol / m 2 The range is e. In TG-DTA measurement (weight change-differential thermal analysis), the crystal transition temperature from boehmite alumina to gamma alumina is 470°C or higher. f.CO adsorption FT-IR measurement (measured using a Fourier transform infrared spectrophotometer) showed a peak at 2230 cm -1 The presence of a Lewis acid that exhibits a peak near

[0018] The method for producing a silica-alumina powder proposed by the present invention is a method for producing the silica-alumina powder, comprising: (A) mixing an aqueous solution containing an alumina hydrate with an aqueous solution containing a silica precursor to prepare an aqueous solution A containing a silica-alumina precursor; (B) a step of adjusting the pH of the aqueous solution A containing the silica-alumina precursor obtained in the step (A) to 8.0 or more, and then heat-treating the aqueous solution A at a temperature in the range of 70 to 180°C for 2 hours or more to obtain a silica-alumina slurry A; (C) separating a solid content from the silica-alumina slurry A to obtain a silica-alumina powder, The alumina raw material used in step (A) is a boehmite alumina (020) crystallite having a diameter of 10 to 50 nm as determined by X-ray diffraction. The mass ratio of silica to alumina is adjusted to fall within the range of 8 / 92 to 20 / 80.

[0019] The fluid catalytic cracking catalyst according to the present invention is a fluid catalytic cracking catalyst containing the above silica-alumina powder.

[0020] Further, the method for producing a fluid catalytic cracking catalyst according to the present invention comprises the steps of: (1) A step of mixing the silica-alumina powder component, the binder component, the clay component (extender), the zeolite component, and the additives to obtain a mixed slurry; (2) spray-drying the mixed slurry obtained in the step (1) to obtain dried particles; (3) A step of washing and drying the dried particles obtained in the step (2) to obtain a fluid catalytic cracking catalyst. Furthermore, instead of step (3), (4) The process preferably includes a step of washing the dried particles obtained in the step (2) and then further exchanging the particles with a rare earth metal to obtain a rare earth metal-exchanged fluid catalytic cracking catalyst. [Effects of the Invention]

[0021] According to the present invention, a silica-alumina powder having excellent thermal stability, a moderate acid density, and a strong Lewis acid strength can be obtained when used in a fluid catalytic cracking catalyst. Therefore, a fluid catalytic cracking catalyst containing the silica-alumina powder can be used in the fluid catalytic cracking of hydrocarbon oils to produce a low coke yield and an excellent gasoline yield. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a graph showing the results of CO adsorption FT-IR measurement of silica-alumina powder according to an example of the present invention. [Figure 2] 1 is a graph showing the results of CO adsorption FT-IR measurement of silica-alumina powder according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0023] The inventors have discovered that by using highly crystalline boehmite as the alumina hydrate, silica-alumina suitable for use in fluid catalytic cracking catalysts can be obtained. The principle behind this is believed to be as follows: Boehmite with high crystallinity has a more regular arrangement, allowing the crystal plane that reacts with silica to be appropriately controlled, thereby enabling specific strong acid sites to be developed in silica-alumina. Furthermore, the use of highly crystalline boehmite increases the amount of acid per surface area of ​​silica-alumina and improves its thermal stability, so when used as a fluid catalytic cracking catalyst, high activity can be expected over a long period of time.

[0024] <Silica alumina powder> The silica-alumina powder of the present invention has the following properties: a. Contains SiO2 in the range of 8 to 20 mass%; b) The crystallite size of the boehmite alumina (020) plane determined by X-ray diffraction is 10 to 50 nm; c. The specific surface area of ​​the silica-alumina powder is 90 to 230 m 2 / g range, d. The acid density, which is the amount of acid per surface area, is 0.75 to 1.00 μmol / m 2 The range is e. In TG-DTA measurement (weight change-differential thermal analysis), the crystal transition temperature from boehmite alumina to gamma alumina is 470°C or higher. f.CO adsorption FT-IR measurement (measured using a Fourier transform infrared spectrophotometer) showed a peak at 2230 cm -1 The presence of a Lewis acid that exhibits a peak near

[0025] The silica-alumina powder according to the present invention is a non-zeolite material. The silica component contained in the powder is in the range of 8 to 20 mass %, preferably 8 to 17 mass %, and more preferably 9 to 15 mass %. If the silica component is below the lower limit, the crystal transition temperature becomes low, and further, in CO adsorption FT-IR measurement (measurement using a Fourier transform infrared spectrophotometer), the crystal transition temperature becomes low at 2230 cm -1 If the upper limit is exceeded, the silica-alumina cannot be used in a fluid catalytic cracking catalyst to obtain a sufficient acid density.

[0026] <Chemical composition (Al, Si, Na, S)> Of the components of the fluid catalytic cracking catalyst of the present invention, the chemical compositions of Al, Si, and Na were measured by inductively coupled plasma emission spectroscopy (ICP), and sulfur (S) was measured by a combustion method.

[0027] <Pyridine adsorption FT-IR measurement> After molding 30 mg of silica-alumina powder into a 20 mm Φ disk, it was placed in an IR cell connected to a vacuum line and subjected to vacuum evacuation treatment at 500 °C for 1 hour. After the pretreatment, the temperature was lowered to 150 °C, and the IR spectra of the sample disk before and after the introduction of pyridine vapor were measured with a FT / IR-4600 manufactured by JASCO Corporation. The quantification of Bronsted acid sites and Lewis acid sites was carried out based on the method described in Non-Patent Document 3.

[0028] <X-ray Diffraction Measurement Conditions> The X-ray diffraction of the silica-alumina powder was measured with a MiniFlex manufactured by Rigaku Corporation. The measurement conditions were as follows: the operation axis was 2θ / θ, CuKα was used as the radiation source, the continuous measurement method was adopted, the voltage was 40 kV, the current was 15 mA, the start angle was 2θ = 5°, the end angle was 2θ = 90°, the sampling width was 0.020°, and the scan speed was 10.000° / min. The crystallite size D of boehmite-type alumina was calculated using the following Scherrer equation for the (020) plane of boehmite alumina (2θ = 14.0 - 15.0°). Crystallite size = (K × λ) / (β × cosθ) K (shape factor): 0.9400 λ (X-ray wavelength): 0.15418 nm β (correction for the broadening of the line width specific to the apparatus): full width at half maximum θ: Bragg angle (°)

[0029] The silica-alumina powder according to the present invention preferably has a crystallite size of 10 - 50 nm, more preferably 10 - 45 nm, for the (020) plane of boehmite alumina. If it is below the lower limit value, when used as a fluid catalytic cracking catalyst, silica-alumina does not show a strong Lewis acid strength with a peak near 2230 cm -1 in the CO adsorption FT-IR measurement (measurement by Fourier transform infrared spectrophotometer). If it exceeds the upper limit value, the surface area and acid amount will decrease significantly, resulting in a decrease in catalytic activity.

[0030] <BET Specific Surface Area Measurement> For the silica-alumina sample powder that was pretreated at 500 °C for 1 hour in an inert gas atmosphere, the adsorption and desorption amounts of N2 were measured using MacSorb-1220 manufactured by Mountech Co., Ltd. The specific surface area was calculated based on the BET one-point method from the obtained desorption amount of N2. The specific surface area of the silica-alumina according to the present invention is 90 to 230 m 2 / g. Preferably, it is in the range of 100 to 210 m 2 / g.

[0031] <Acid density> From the sum (μmol / g) of the Bronsted acid amount and the Lewis acid amount measured by the above pyridine adsorption FT-IR and the above BET specific surface area (m 2 / g), the acid density (μmol / m 2 ), which is the acid amount per unit surface area, was determined. The acid density of the silica-alumina according to the present invention is 0.75 to 1.00 μmol / m 2 . Preferably, it is 0.80 to 1.00 μmol / m 2 , more preferably in the range of 0.80 to 0.90 mol / m 2 . By setting the acid density within this range, sufficient catalytic activity can be obtained when used as a fluid catalytic cracking catalyst.

[0032] <TG-DTA (Thermogravimetric-Differential Thermal Analysis) measurement> Using a TG-DTA (Thermogravimetric-Differential Thermal Analysis) apparatus (Thermo Plus TG8120) manufactured by Rigaku Corporation, while introducing air at a blowing rate of 50 ml / min, the measurement was carried out up to 1000 °C at a heating rate of 10 °C / min, and the thermal behavior of the powdered sample was recorded. Alpha alumina was used as the standard substance. The crystal dislocation temperature of the boehmite alumina to gamma alumina of the silica-alumina according to the present invention is 470 °C or higher. In this temperature range, it can be said to have high thermal stability.

[0033] <CO adsorption FT-IR measurement> 30 mg of silica alumina powder was molded into a 20 mm diameter disk, then placed in an IR cell connected to a vacuum line and subjected to evacuation treatment at 500°C for 1 hour. After pretreatment, the temperature was lowered to -176°C, and an inert gas (He) was introduced at 100 Pa to bring the sample temperature close to -176°C. Next, the sample was evacuated, and CO was gradually introduced at 1 Pa, 5 Pa, 5 Pa (second time), and 10 Pa to confirm the changes in the IR spectrum resulting from the CO stretching vibration. Figures 1 and 2 show the difference spectra before and after CO introduction. The stronger the Lewis acid strength, the higher the CO stretching vibration shifts to the higher wavenumber side, reaching 2230 cm. -1 The appearance of a peak in this vicinity indicates the presence of a Lewis acid with strong acid strength. The silica-alumina according to the present invention exhibits a CO adsorption FT-IR measurement of 2230 cm -1 It is characterized by the presence of Lewis acids that show peaks around this area.

[0034] <Method of manufacturing silica alumina powder> The method for producing silica-alumina powder is as follows: (A) mixing an aqueous solution containing an alumina hydrate with an aqueous solution containing a silica precursor to prepare an aqueous solution A containing a silica-alumina precursor; (B) a step of adjusting the pH of the aqueous solution A containing the silica-alumina precursor obtained in the step (A) to 8.0 or more, and then heat-treating the aqueous solution A at a temperature in the range of 70 to 180°C for 2 hours or more to obtain a silica-alumina slurry A; (C) a step of separating a solid content from the silica-alumina slurry A to obtain a silica-alumina powder; and optionally washing and drying (calcining) to obtain silica-alumina powder. The alumina raw material used in step (A) is a boehmite alumina (020) crystallite having a diameter of 10 to 50 nm as determined by X-ray diffraction. The mass ratio of silica to alumina is adjusted to fall within the range of 8 / 92 to 20 / 80.

[0035] <Alumina raw material> The alumina raw material preferably has a crystallite diameter of the (020) plane of boehmite alumina measured by X-ray diffraction in the range of 10 to 50 nm, preferably 10 to 45 nm. Below the lower limit, the crystallinity of the boehmite alumina is low, making it impossible to appropriately control the thermal stability and acidity when used as a raw material for silica-alumina powder. Above the upper limit, the surface area of ​​the boehmite alumina is low, and when used as a raw material for silica-alumina powder, the surface area and acidity decrease, resulting in a decrease in catalytic activity. Commercially available alumina may be selected, or it may be prepared using an aqueous solution of an alkali metal aluminate or aluminum salt.

[0036] For example, an aluminum sulfate aqueous solution is added to a sodium aluminate aqueous solution and stirred. The resulting alumina slurry is washed with warm water to reduce the Na2O content of the washed alumina cake to 2% or less by dry weight and the SO4 content to 1% or less by dry weight. The washed alumina cake is then dispersed in pure water to obtain a washed alumina slurry. An aqueous sodium hydroxide solution is then added to adjust the pH, and the mixture is aged while being stirred. After aging, the mixture is cooled to obtain a crystalline boehmite slurry.

[0037] <Silica precursor-containing aqueous solution> In an embodiment of step (A) of the method for producing silica-alumina powder according to the present invention, an aqueous solution containing alumina hydrate is mixed with an aqueous solution containing a silica precursor. The source of the silica compound is preferably selected from the group consisting of silicic acid, silicic acid colloidal solution, water-soluble silicates, cationic silicon salts (e.g., hydrated sodium metasilicate), Ludox (registered trademark, ammonia type or alkali type), and quaternary ammonium silicate. The silicic acid colloidal solution may be prepared using methods known to those skilled in the art. A desalted silicic acid solution is preferred as the silica compound. The source of this completely soluble silicon compound may also be an orthosilicic acid solution (H2SiO4, HO) prepared by ion-exchanging a water-soluble alkali silicate on a resin.

[0038] <Process (A)> A step of mixing an aqueous solution containing an alumina hydrate with an aqueous solution containing a silica precursor to prepare an aqueous solution A containing a silica-alumina precursor. The combination of an alumina compound with a completely soluble silica compound or a partially soluble silica compound and an alumina compound corresponds to contacting alumina species and silica species having specific sizes and chemical reactivities in the mixture of step (A) and controlling the interaction between the chemical species. Controlling the interaction in this way contributes to improving the homogeneity of the silica-alumina powder of the present invention. In this preparation method, the interaction activity between the silica species and alumina species may be controlled in any step before the heat treatment depending on the chemical properties of the alumina compound and silica compound used to prepare the silica-alumina powder. In one non-limiting example, a partially soluble alumina compound of the hydrated aluminum type, Al2O3·nH2O (boehmite), may be mixed in an aqueous medium with a fully soluble silica compound of the decationized orthosilicate type under various controlled synthesis conditions (pH, temperature, etc.), or a partially soluble alumina compound of the hydrated alumina type, Al2O3·nH2O (boehmite), may be mixed with a commercially available fully soluble silica (Ludox®) colloidal solution during the forming process after machining. Following the mixing in step (A) of the silica-alumina powder preparation method, a heat treatment is carried out in the presence of water (gas or liquid phase) to ultimately achieve the micrometer-level (or nanometer-level) homogeneity between the alumina and silica species required to obtain the acidity and texture characteristics of the silica-alumina powder used in fluid catalytic cracking of the present invention.

[0039] In the preparation of this step (A), the temperature of the aqueous solution is preferably in the range of 10 to 60° C. Preparation at a temperature that is too far outside this range is not preferred because a homogeneous reaction between silica and alumina does not occur and the silica-alumina does not exhibit high thermal stability, appropriate acid density, or strong Lewis acid strength.

[0040] Prior to the addition of the compound containing silicon in whole or in part, this applies to hydrated alumina powder, spray-dried hydrated alumina powder, dispersions and suspensions of hydrated alumina, and combinations thereof.

[0041] In order to increase the diameter of the mesopores in the finally obtained silica-alumina powder, as disclosed in U.S. Patent No. 4,066,574, it is particularly effective to prepare an aqueous suspension or dispersion of an alumina component (an alumina compound partially soluble in an acidic medium) such as alumina monohydrate to obtain the mixture of step (1), then neutralize the mixture with a basic solution (ammonia, etc.), and finally add the mixture simultaneously or sequentially to a completely soluble silica compound (a decationized orthosilicic acid solution, etc.). The suspension is vigorously stirred and mechanically homogenized, and optionally the dry matter content is adjusted by filtration and rehomogenized, after which the product is heat-treated and optionally shaped simultaneously or sequentially.

[0042] In the following description of the above method, the first "homogenization" of the mixture is often performed by mechanical treatment. For example, when a product containing a solid fraction is used in the form of a liquid such as a suspension, a powder, a filtered precipitate, or the like, the product is dispersed by vigorous stirring. Mechanical homogenization of dispersions is widely known to those skilled in the art. Homogenization may be performed by mechanical methods known to those skilled in the art, for example, using a batch reactor, a continuous mixer, or a mill. Mixing may be performed in a plug-flow reactor, particularly a static reactor. A Lightnin' reactor may also be used. A colloid mill such as an Ultraturrax® turbine or a Staro® turbine, or a Staro® colloid mill may also be used. A commercially available IKA® colloid mill may also be used.

[0043] <Process (B)> A step of adjusting the pH of the aqueous solution A containing the silica-alumina precursor obtained in the step (A) to 8.0 or more, and then heat-treating it at a temperature in the range of 70 to 180°C for 2 hours or more to obtain a silica-alumina slurry A. In step (B) of the method for preparing silica-alumina powder of the present invention, the pH of the aqueous solution A obtained in step (A) is adjusted to 8.0 or higher, and then the aqueous solution A is heat-treated at a temperature in the range of 70 to 180°C for 2 hours or more, thereby ensuring the homogeneity of the silica-alumina powder. The pH of aqueous solution A in this step is 8.0 or higher, preferably in the range of 9.0 to 11.0. If the pH is too far outside this range, the silica and alumina do not react homogeneously, and the resulting silica-alumina does not exhibit high thermal stability, a moderate acid density, or a strong Lewis acid strength, which is undesirable. The temperature of the aqueous solution is preferably in the range of 70 to 180°C. Below the lower limit, the reaction of the silica-alumina precursor becomes insufficient. Above the upper limit, dissolution of the silica-alumina proceeds, and the resulting silica-alumina does not exhibit high thermal stability, a moderate acid density, or a strong Lewis acid strength, which is undesirable. Specifically, the solid obtained in step (A) is heat-treated by contacting it with water (gas or liquid phase). Heat treatment may be performed at any stage of the preparation. While this treatment may improve the mobility of the silica component, the present invention is not limited thereto. While there is no particular upper limit on the heat treatment time, it is preferable to set it to approximately 48 hours from an economical standpoint.

[0044] <Process (C)> A process of cooling the aqueous solution heated in the step (B) and separating the solid content to obtain silica-alumina powder. This is the process of obtaining silica-alumina powder by washing and drying (calcining). Conventional methods can be used.

[0045] <Method of manufacturing fluid catalytic cracking catalyst> (1) A step of mixing the silica-alumina powder component, the binder component, the clay component (extender), the zeolite component, and the additives to obtain a mixed slurry; (2) spray-drying the mixed slurry obtained in the step (1) to obtain dried particles; (3) A method for producing a fluid catalytic cracking catalyst, comprising the step of washing and drying the dried particles obtained in the step (2) to obtain a fluid catalytic cracking catalyst. Also, instead of step (3), (4) A method for producing a fluid catalytic cracking catalyst, comprising the step of washing the dried particles obtained in the step (2) and then further exchanging the particles with a rare earth metal to obtain a rare earth metal-exchanged fluid catalytic cracking catalyst.

[0046] The method for producing a fluid catalytic cracking catalyst can be performed by the method described in JP-A-2020-032350 or JP-A-2020-032352. [Example]

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0048] Example 1 Diluted water glass with an SiO2 concentration of 5% by mass was subjected to ion exchange using a cation exchange resin to prepare a desalted silicic acid solution with a pH of 2.67. 1750 g of pure water was added to 1440 g of desalted silicic acid solution with an SiO2 concentration of 5% by mass, and a 15% by mass aqueous ammonia solution was added to adjust the pH to 10.8. CATAPAL 200 ((020) crystallite diameter: 22.5 nm, specific surface area: 94 m) manufactured by Sasol, shown in Table 1, AA, was used. 2 / g): 810 g (Al2O3 concentration 80 mass%) was added to the above diluted silicic acid solution whose pH had been adjusted to 10.8, and stirred at room temperature for 30 minutes. Further, a 15 mass% aqueous ammonia solution was added to adjust the pH of the slurry to 10.8. Next, the mixture was loaded into an autoclave, heated to 180°C over 3 hours with stirring, and heat-treated for 8 hours to obtain silica-alumina slurry (1).

[0049] Silica-alumina slurry (1) was dried at 130°C for 10 hours and pulverized in a mixer. This powder was washed with warm water, then ion-exchanged with an aqueous ammonium sulfate solution and washed with warm water to obtain a washed cake. The washed cake was dried at 130°C for 10 hours to obtain silica-alumina powder S1. The physical properties of silica-alumina powder S1 are shown in Table 2-1, and the CO adsorption FT-IR spectrum is shown in Figure 1.

[0050] [Preparation of fluid catalytic cracking catalyst] 1429 g of water glass (SiO2 concentration 17.5% by mass) and 571 g of sulfuric acid (adjusted to a concentration of 25% by mass, hereinafter the same) were added simultaneously and continuously to prepare 2000 g of silica sol (an example of a silica-based binder) with a SiO2 concentration of 12.5% ​​by mass. To this silica sol, 1625 g (dry basis) of kaolin clay, 250 g (dry basis) of silica-alumina powder S1, and 375 g (dry basis) of ultra-stabilized Y-type zeolite powder (SiO2 / Al2O3 molar ratio 7.1, unit crystallite size 2.440 nm, hereinafter the same) were added to prepare a mixed slurry. The mixed slurry was formed into droplets and spray-dried in a spray dryer with an inlet temperature of 250 °C and an outlet temperature of 150 °C to obtain spherical particles with an average particle size of 70 μm. The resulting spray-dried particles were washed with warm water, then subjected to ion exchange with an aqueous ammonium sulfate solution and an aqueous rare earth metal chloride solution, followed by hot water washing, and then subjected to ion exchange treatment to obtain 1.0 mass% RE2O3. The catalyst particles were then dried in a dryer at 150°C to obtain a fluid catalytic cracking catalyst C1.

[0051] Example 2 6280 g of an aluminum sulfate aqueous solution (Al2O3 concentration 2.5 mass%) was added to 6530 g of a sodium aluminate aqueous solution (Al2O3 concentration 5 mass%) and stirred at 65°C for 1 hour to obtain an alumina slurry. The alumina slurry was then washed with warm water to adjust the Na2O content of the washed alumina cake to 2% or less by dry mass and the SO4 content to 1% or less by dry mass. Pure water was then added to the washed alumina cake to prepare a washed alumina slurry with an Al2O3 concentration of 12.5%, and a 48 mass% sodium hydroxide aqueous solution was added to adjust the pH to 11.5. The mixture was then aged at 95°C for 20 hours with stirring to obtain a crystalline boehmite slurry (hereinafter referred to as slurry A, AB in Table 1) ((020) crystallite diameter: 10.7 nm, specific surface area: 178 m 2 / g) was obtained.

[0052] Diluted water glass with an SiO2 concentration of 5% by mass was subjected to ion exchange using a cation exchange resin to prepare a desalted silicic acid solution with a pH of 2.67. 620 g of the 5% by mass desalted silicic acid solution was added with a 15% by mass aqueous ammonia solution to adjust the pH to 10.8. Slurry A: 3100 g (Al2O3 concentration 9% by mass) of the desalted silicic acid solution adjusted to pH 10.8 was added and stirred at room temperature for 30 minutes. Next, the mixture was aged at 95°C for 8 hours while stirring to obtain silica alumina slurry (2).

[0053] Silica-alumina powder S2 was obtained from silica-alumina slurry (2) by the same procedure as in Example 1. The physical properties of silica-alumina powder S2 are shown in Table 2-1, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0054] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst C2 was obtained by the same procedure as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder S2.

[0055] Example 3 Silica-alumina slurry (3) was obtained by the same procedure as in Example 2, except that the amount of demineralized silicic acid solution with an SiO2 concentration of 5 mass % was changed to 985 g. Silica-alumina slurry (3) was prepared in the same manner as in Example 1 to obtain silica-alumina powder S3. The physical properties of silica-alumina powder S3 are shown in Table 2-1, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0056] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst C3 was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder S3.

[0057] Example 4 The same operation as in Example 2 was carried out to obtain silica alumina slurry (4), except that the aging process of the mixed slurry of slurry A and desalted silicic acid solution adjusted to pH 10.8 was changed from 8 hours at 95 ° C to 8 hours at 150 ° C in an autoclave. Silica-alumina powder S4 was obtained from silica-alumina slurry (4) by the same procedure as in Example 1. The physical properties of silica-alumina powder S4 are shown in Table 2-1, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0058] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst C4 was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder S4.

[0059] Example 5 According to the method described in Example 4 of Patent Document 6, CATAPAL-A manufactured by Sasol was used as the alumina slurry raw material, the amount of alumina slurry added during the heat treatment was reduced by 70%, and after the addition of the alumina slurry was completed, the heat treatment was carried out for 1 hour to prepare a crystalline boehmite slurry (hereinafter referred to as slurry B, AC in Table 1) ((020) crystallite diameter: 39.0 nm, specific surface area: 85 m 2 / g) was obtained.

[0060] Diluted water glass with an SiO2 concentration of 5% by mass was subjected to ion exchange using a cation exchange resin to prepare a desalted silicic acid solution with a pH of 2.67. 620 g of the 5% by mass desalted silicic acid solution was added with a 15% by mass aqueous ammonia solution to adjust the pH to 10.8. Slurry B: 2536 g (Al2O3 concentration 11% by mass) of the above desalted silicic acid solution adjusted to pH 10.8 was added and stirred at room temperature for 30 minutes. The mixture was then loaded into an autoclave, heated to 180°C over 3 hours with stirring, and heat-treated for 8 hours to obtain silica-alumina slurry (5).

[0061] Silica-alumina slurry (5) was prepared in the same manner as in Example 1 to obtain silica-alumina powder S5. The physical properties of silica-alumina powder S5 are shown in Table 2-1, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0062] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst C5 was obtained by the same procedure as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder S5.

[0063] (Comparative Example 1) The physical properties of Sasol alumina CATAPAL200 are shown as SA in Table 2-2, and the FT-IR spectrum of CO adsorption is shown in Figure 2.

[0064] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst CA was obtained in the same manner as in Example 1, except that the silica-alumina slurry S1 was changed to alumina CATAPAL 200 (SA) manufactured by Sasol.

[0065] (Comparative Example 2) Slurry A was dried at 130°C for 10 hours and pulverized in a mixer. This powder was washed with warm water, then ion-exchanged with an aqueous ammonium sulfate solution and washed with warm water to obtain a washed alumina cake. The washed alumina cake was dried at 130°C for 10 hours to obtain crystalline boehmite powder A. The physical properties of alumina powder A are shown as SB in Table 2-2, and the CO adsorption FT-IR spectrum is shown in Figure 2.

[0066] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst (R2) was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to alumina powder A (SB).

[0067] (Comparative Example 3) A silica-alumina slurry (6) was obtained by the same procedure as in Example 2, except that the amount of demineralized silicic acid solution with an SiO2 concentration of 5 mass % was changed to 356 g. Silica-alumina slurry (6) was prepared in the same manner as in Example 1 to obtain silica-alumina powder SC. The physical properties of silica-alumina powder SC are shown in Table 2-2, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0068] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst CC was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder SC.

[0069] Comparative Example 4 Diluted water glass with an SiO2 concentration of 5% by mass was subjected to ion exchange using a cation exchange resin to prepare a desalted silicic acid solution with a pH of 2.67. 1696 g of pure water was added to 1440 g of desalted silicic acid solution with an SiO2 concentration of 5% by mass, and a 15% by mass aqueous ammonia solution was added to adjust the pH to 10.8. CATAPAL-A ((020) crystallite diameter 2.9 nm, specific surface area 266 m) manufactured by Sasol, shown as AC in Table 1, was used. 2 / g): 864 g (Al2O3 concentration 75 wt%) was added to a diluted silicic acid solution whose pH had been adjusted to 10.8, and stirred at room temperature for 30 minutes. Furthermore, a 15 mass% aqueous ammonia solution was added to adjust the pH of the slurry to 10.8. The mixture was then loaded into an autoclave, heated to 150°C over 2 hours and 30 minutes with stirring, and heat-treated for 8 hours to obtain a silica-alumina slurry (7).

[0070] Silica-alumina powder SD was obtained from silica-alumina slurry (7) by the same procedure as in Example 1. The physical properties of silica-alumina powder SD are shown in Table 2-2, and the spectrum of CO adsorption FT-IR measurement is shown in FIG.

[0071] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst CD was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder SD.

[0072] (Comparative Example 5) The physical properties of Sasol silica alumina SIRAL20 are shown as SE in Table 2-2, and the FT-IR spectrum of CO adsorption is shown in Figure 2.

[0073] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst CE was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to silica-alumina SIRAL20 (SE) manufactured by Sasol.

[0074] (Comparative Example 6) According to the method described in Example 4 of Patent Document 7, CATAPAL-A manufactured by Sasol was used as the alumina slurry raw material, and after the addition of the alumina slurry was completed, heat treatment was carried out for 1 hour to prepare a crystalline boehmite slurry (hereinafter referred to as Slurry C, AE in Table 1) ((020) crystallite diameter: 67.3 nm, specific surface area: 52 m 2 / g) was obtained.

[0075] Diluted water glass with an SiO2 concentration of 5% by mass was subjected to ion exchange using a cation exchange resin to prepare a desalted silicic acid solution with a pH of 2.67. 620 g of the 5% by mass desalted silicic acid solution was added with a 15% by mass aqueous ammonia solution to adjust the pH to 10.8. Slurry C: 2536 g (Al2O3 concentration 11% by mass) of the above desalted silicic acid solution adjusted to pH 10.8 was added and stirred at room temperature for 30 minutes. The mixture was then loaded into an autoclave, heated to 180°C over 3 hours with stirring, and heat-treated for 8 hours to obtain silica-alumina slurry (8).

[0076] Silica-alumina powder SF was obtained from silica-alumina slurry (8) by the same procedure as in Example 1. The physical properties of the silica-alumina powder SF are shown in Table 2-2, and the spectrum of the CO adsorption FT-IR measurement is shown in FIG.

[0077] [Preparation of fluid catalytic cracking catalyst] A fluid catalytic cracking catalyst CF was obtained in the same manner as in Example 1, except that the silica-alumina powder S1 was changed to the silica-alumina powder SF.

[0078] [Catalytic activity evaluation test] For each of the catalysts in the examples and comparative examples, a catalyst performance evaluation test was conducted using an Advanced Cracking Evaluation Micro Activity Test (ACE-MAT) under the same crude oil and the same reaction conditions. However, before conducting these performance evaluation tests, nickel and vanadium were deposited on the surface of each catalyst in amounts of 1000 ppm by mass (the mass of nickel divided by the mass of the catalyst) and 2000 ppm by mass (the mass of vanadium divided by the mass of the catalyst), respectively, and then the catalyst was subjected to a pseudo-equilibration treatment by steaming.

[0079] The operating conditions for the activity evaluation test were as follows: Feedstock: Desulfurized atmospheric residue (DSAR) of crude oil + desulfurized vacuum gas oil (DSVGO) (50+50) Catalyst / through oil mass ratio (C / O): 3.75 and 5.00 Reaction temperature: 520℃ 1) Conversion rate = 100 - (LCO + HCO) 2) Boiling point range of gasoline: 30~216℃ 4) Boiling point range of LCO: 216-343°C (LCO: Light Cycle Oil) 5) Boiling point range of HCO: 343°C+ (HCO: Heavy Cycle Oil)

[0080] The results of the activity evaluation test are shown in Table 3. The inventive examples can be evaluated as fluid catalytic cracking catalysts with lower coke yields and higher gasoline yields than the comparative examples.

[0081] [Table 1]

[0082] [Table 2-1]

[0083] [Table 2-2]

[0084] [Table 3]

Claims

1. A silica-alumina powder having the following characteristics a to f. a. SiO ２ in the range of 8 to 20 mass%; b. The crystallite size of the boehmite alumina (020) plane determined by X-ray diffraction is 10 to 50 nm; c. The specific surface area of ​​the silica-alumina powder is 90 to 230 m ２ / g, d. The acid density, which is the amount of acid per surface area, is 0.75 to 1.00 μmol / m ２ The range is e. In TG-DTA measurement (weight change-differential thermal analysis), the crystal transition temperature from boehmite alumina to gamma alumina is 470°C or higher; f. In CO adsorption FT-IR measurement (measured by a Fourier transform infrared spectrophotometer), －１ The presence of a Lewis acid that exhibits a peak near

2. Specific surface area is 85 to 178 m ２ A step (A) of mixing an aqueous solution containing an alumina hydrate in an amount of 1 / g with an aqueous solution containing a silica precursor to prepare an aqueous solution A containing a silica-alumina precursor at 10 to 60°C; a step (B) of adjusting the pH of the aqueous solution A obtained in the step (A) to 8.0 or more, and then heat-treating the aqueous solution A at 70 to 180°C for 2 hours or more to obtain a silica-alumina slurry A; and (C) a step of obtaining a silica-alumina powder by separating a solid content from the silica-alumina slurry A, When the alumina hydrate is subjected to X-ray diffraction analysis, the crystallite size of the boehmite alumina (020) plane is 10 to 50 nm, the silica precursor is at least one of silicic acid, a silicic acid colloidal solution, a water-soluble silicate, a cationic silicon salt, Ludox (registered trademark, ammonia type or alkali type), and a quaternary ammonium silicate; In the step (A), the aqueous solution A is prepared so that the mass ratio of silica to alumina is 8 / 92 to 20 / 80.

3. A fluid catalytic cracking catalyst comprising the silica-alumina powder according to claim 1.

4. A process (1) of mixing the silica-alumina powder component according to claim 1, a binder component, a clay component (filler), a zeolite component, and an additive to obtain a mixed slurry; (2) spray-drying the mixed slurry to obtain dried particles; and (3) washing and drying the dried particles to obtain a fluid catalytic cracking catalyst.

5. Instead of the step (3), 5. The method for producing a fluid catalytic cracking catalyst according to claim 4, further comprising the step (4) of washing the dried particles and then exchanging them with a rare earth metal to obtain a rare earth metal-exchanged fluid catalytic cracking catalyst.

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