Mesoporous pseudoboehmite with a hydroxyl-rich surface, catalytic cracking catalysts containing pseudoboehmite, and their preparation and use

Abstract

The present invention relates to mesoporous pseudo-boehmite having a surface rich in hydroxyl groups, a method for preparing the same, a catalytic cracking catalyst containing the mesoporous pseudo-boehmite, and a method for preparing and using the catalytic cracking catalyst, wherein the pseudo-boehmite has a most probable pore diameter of more than 4.5 nm and not more than 12 nm.

Description

Detailed Description of the Invention

[0001] [Technical Field] The present invention relates to mesoporous pseudoboehmite rich in surface hydroxyl groups and a method for preparing the same. Further, the present invention relates to a catalytic cracking catalyst containing the above mesoporous pseudoboehmite, a method for preparing the same, and a method for applying the same.

[0002] [Background Art] Pseudoboehmite represented by the chemical formula AlOOH·nH2O (0 < n < 1, particularly 0.08 to 0.62) is an aluminum oxide compound having a higher water content and a smaller crystal size than boehmite. Pseudoboehmite is a crystal phase that easily occurs during the synthesis of aluminum hydroxide and has incomplete crystallization. Its typical crystal form is very thin wrinkled flakes.

[0003] Methods for preparing pseudo-boehmite mainly include the aluminum alcoholate hydrolysis method and the precipitation method. Precipitation methods are divided into two categories: acid and alkaline methods. The aluminum alcoholate hydrolysis method uses metallic aluminum and higher alcohols (n-pentanol, n-hexanol, isopropanol) as raw materials. The aluminum alcoholate is reacted with the alcohol in the presence of a catalyst to form aluminum alcoholate, which is then hydrolyzed to obtain pseudo-boehmite. However, this method is expensive and complex to manufacture. The alkaline precipitation method involves neutralizing and precipitating acidic aluminum salts with alkali to prepare pseudo-boehmite. Commonly used aluminum salts include Al2(SO4)3, Al(NO3)3, and AlCl3, and commonly used alkaline precipitants include NaOH, NH3·H2O, NaAlO2, and Na2CO3. The acid precipitation method refers to the preparation of pseudoboehmite by neutralizing and precipitating alkaline aluminate with acid. The alkaline aluminate is typically sodium (meta)aluminate, and the acid used can be a strong acid (e.g., HNO3, H2SO4) or a weak acid (e.g., NH4HCO3, NaHCO3) and CO2. The NaAlO2-CO2 method is also known as the carbonization method. The carbonization method for pseudoboehmite preparation utilizes the alumina production process by sintering, using the intermediate product NaAlO2 solution and CO2 waste gas from aluminum production plants as reactants. This process is simple, and by-products and waste liquids generated during the production process can be recycled back into the alumina production process. This makes it the lowest-cost method for industrially producing pseudoboehmite to date.

[0004] Pseudoboehmite is widely used in catalysts in petroleum refining and petrochemistry, and is often used as a binder for catalytic cracking catalysts and a precursor for hydrogenation catalyst supports (γ-Al2O3). Pseudoboehmite is an important raw material in semi-synthetic catalytic cracking catalysts. After acidification, pseudoboehmite has good binding properties and can form a specific mesoporous structure after catalyst preparation and formation.

[0005] Pseudoboehmite prepared by conventional carbonization methods has low crystallinity and a most probable (mode) pore size of only 3.8 nm. When prepared as a catalytic cracking catalyst, pseudoboehmite can only achieve a 3.8 nm mesoporous structure. The relatively large molecular size of the feedstocks being catalytically cracked significantly hinders diffusion within the 3.8 nm pores. This hinders efficient molecular diffusion and conversion of heavy oil feedstocks, preventing reduction in coke formation and improved product distribution. Currently, there are no reports of the use of pseudoboehmite prepared by carbonization in catalytic cracking catalysts to achieve a larger most probable pore size distribution. Furthermore, conventional pseudoboehmite with larger pore sizes currently has poor attrition resistance and cannot directly form a pore structure with a larger most probable pore size after acidification.

[0006] Catalytic cracking catalysts typically contain molecular sieves, binders, and clays. Commonly used binders are dialuminum binder-alumina and aluminum sol. To increase the yield of high-value-added products, catalytic cracking catalysts typically require a high molecular sieve content. However, increasing the molecular sieve content often results in a decrease in the catalyst's attrition resistance. Furthermore, the molecular sieves commonly used in catalytic cracking contain primarily micropores, with few mesopores or macropores. Pseudoboehmite is often used as the matrix for catalytic cracking catalysts and as a precursor for hydrogenation catalyst supports (γ-Al2O3). After acidification, pseudoboehmite has good binding properties and can form a specific mesoporous structure after catalyst preparation and formation. However, the strength of catalytic cracking catalyst products obtained using conventional pseudoboehmite is low. Furthermore, when conventional pseudoboehmite is used, larger pore diameters are often not obtained, and the most probable pore diameter is less than 4.5 nm, so that a pore structure exceeding 5 nm cannot be formed in the resulting catalytic cracking catalyst.

[0007] [Summary of the Invention] The first technical problem to be solved by the present invention is to provide mesoporous pseudo-boehmite that has good binding properties and is rich in surface hydroxyl groups.

[0008] A second technical problem to be solved by the present invention is to provide a method for preparing the pseudo-boehmite.

[0009] The third technical problem to be solved by the present invention is to provide a method for preparing a catalytic cracking catalyst using pseudo-boehmite as a binder, which can provide a catalytic cracking catalyst with better attrition resistance.

[0010] The fourth technical problem to be solved by the present invention is to provide a catalytic cracking catalyst prepared by the above-mentioned method and a method for applying the same.

[0011] More specifically, the present invention provides the following three sets of technical solutions A, B, and C:

[0012] [Technical solution A] A1. Pseudo-boehmite characterized by having any one, two, or three of the following characteristics (a), (b), and (c): (a) alone, (b) alone, (c) alone, a combination of (a) and (b), a combination of (a) and (c), a combination of (b) and (c), or a combination of (a), (b), and (c). (a) the pseudo-boehmite has a most probable pore diameter of greater than 4.5 nm and less than or equal to 12 nm, for example, 4.8 nm to 11 nm, 5 nm to 10 nm, 5.5 nm to 9 nm, 6 nm to 8.5 nm, 7 nm to 9 nm, 5.2 nm to 7.6 nm, or 5.2 nm to 7.5 nm; (b) I of the pseudo-boehmite 3000~3800 is 6.0cm -1 mg -1 ~8.5cm -1 mg -1 , e.g. 6.2cm -1 mg -1 ~8.3cm -1 mg -1 and I 3000~3800is 3000cm -1 ~3800cm -1 represents the infrared absorption intensity of the surface hydroxyl group of the pseudo-boehmite in the infrared wavelength range of I 3000~3800 The calculation method is 3000cm for the mass of the sample (unit: mg). -1 ~3800cm -1 The area of ​​the absorption peak of the sample in the range (unit: cm -1 ) is the ratio of; Here, the infrared absorption intensity of the surface hydroxyl groups of the sample is measured by a Fourier transform infrared spectrophotometer, and the specific method is as follows: After the sample is thoroughly crushed, a 10 mg to 20 mg sample is taken and pressed to form a self-supporting piece; After accurate weighing, the sample was transferred to the sample holder of the in-situ cell and subjected to vacuum treatment; the sample was 1.0 × 10 -3 Purification was carried out under high vacuum conditions of 100 Pa (absolute pressure) at a temperature of 450°C for 2 hours; After purification, the mixture was cooled to room temperature and -1 ~4000cm -1 In the range of 4.0 cm -1 The infrared absorption signal of the hydroxyl group is obtained by scanning at a resolution of 0.05; After data processing of the absorption signals, an infrared absorption spectrum of the hydroxyl group is obtained, with wave number as the abscissa and absorbance as the ordinate. Absorbance: the logarithm to the base 10 of the ratio of the incident light intensity before the light passes through a material to the transmitted light intensity after the light passes through the material, i.e., lg(I0 / I1), where I0 is the incident light intensity and I1 is the transmitted light intensity; (c) the crystal size D of the pseudo-boehmite (130) and D (020) The ratio of (130) / D (020) = 1.0 to 1.5, for example, 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3 or 1.13 to 1.26; The crystal size D is measured by powder X-ray diffraction (XRD) and is calculated by the Scherrer equation

number

number

number

[0013] A2. Pseudo-boehmite according to any one of the above technical solutions, characterized in that the molecular formula of pseudo-boehmite is AlOOH·nH2O (n=0.08~0.62).

[0014] A3. The crystal size of the pseudo-boehmite is D (130) The pseudo-boehmite according to any one of the above technical solutions, characterized in that the particle size is 4 nm to 10 nm, for example, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm.

[0015] A4. The pseudo-boehmite according to any one of the above technical solutions, characterized in that the pseudo-boehmite has a crystallinity of 85% to 110%, for example, 88% to 108%, 90% to 105%, or 92% to 103%.

[0016] A5. The pseudo-boehmite according to any one of the above technical solutions, characterized in that the peptization index of the pseudo-boehmite is 90% to 100%, for example, 93% to 99%, or 94% to 98%.

[0017] A6. The pore volume of the pseudo-boehmite is 0.3 cm 3 / g~0.58cm 3 / g, e.g., 0.31 cm 3 / g~0.52cm 3 / g, 0.33cm 3 / g~0.5cm 3 / g or 0.34cm 3 / g~0.46cm 3 / g.

[0018] A7. A method for preparing pseudoboehmite, comprising the following steps: (1) reacting a sodium (meta)aluminate solution with CO to form a first slurry; preferably, the molar ratio of the two, calculated as NaAlO and CO, is in the range of 0.5 to 2 times, e.g., 0.833 to 1.2 times, or 0.9 to 1.1 times the theoretical equivalent ratio, i.e., when the theoretical equivalent ratio is 2:1, the actual molar ratio of the two is (1 to 4):1, e.g., (1.67 to 2.4):1, or (1.8 to 2.2):1; (2) Aging the first slurry under certain conditions, adding aqueous ammonia and / or a precursor capable of forming NH3 (e.g., urea) as a hydroxyl group regulator during the aging to obtain an aged slurry, wherein the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C; the aging under certain conditions is preferably a step of first static aging, followed by aging under stirring; (3) filtering, washing, and drying the aged slurry.

[0019] A8. The method for preparing pseudo-boehmite according to any of the above technical solutions, wherein in step (1), the pH value of the sodium (meta)aluminate solution at the end of the reaction with CO2 is 8.5 to 10.5, for example 9.2 to 10.3, and the Al2O3 concentration of the sodium (meta)aluminate solution is 5 g / L to 60 g / L, for example 8 g / L to 45 g / L.

[0020] A9. The method for preparing pseudo-boehmite according to any one of the above technical solutions, characterized in that in step (1), the conditions for the reaction of the sodium (meta)aluminate solution with CO2 include introducing a CO2-containing gas having a CO2 concentration of 20 to 100 vol%, for example 40 to 100 vol%, 30 to 90 vol%, or 40 to 80 vol% (the remainder being an inert gas such as nitrogen) into the sodium (meta)aluminate solution to cause a reaction, the reaction starting temperature being 10°C to 35°C, and the reaction ending temperature being 15°C to 55°C.

[0021] A10. The method for preparing pseudo-boehmite according to any one of the above technical solutions, wherein in step (2), the aging temperature of the slurry is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, the aging pressure is 0.2MPa to 1.0MPa, and the aging time is 2 hours to 11.5 hours, for example, 2 hours to 10 hours, or 3.5 hours to 10.5 hours.

[0022] A11. The method for preparing pseudo-boehmite according to any one of the above technical solutions, characterized in that in step (2), the time for the static aging is 1 hour to 8 hours, for example, 1 hour to 6 hours, or 2.5 hours to 6 hours, 1 hour to 4 hours, or 2 hours to 3 hours, the time for the aging under stirring is 1 hour to 6 hours, for example, 1 hour to 4.5 hours, the stirring speed for the aging under stirring may be 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm, and the aging is preferably isothermal aging.

[0023] A12. The method for preparing pseudo-boehmite according to any one of the above technical solutions, wherein the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, and the aging is preferably isothermal aging.

[0024] A13. The method for preparing pseudo-boehmite according to any one of the above technical solutions, characterized in that the hydroxyl group regulator is added before static aging, during static aging, after a certain period of static aging and before aging under stirring, or after the end of static aging and before the start of aging under stirring, or a combination thereof; the hydroxyl group regulator is 0.5 to 2 wt %, for example 0.7 to 1.8 wt %, based on the first slurry calculated as alumina; and the concentration of ammonia in the ammonia water is preferably 15 to 25 wt %, for example 20 wt %.

[0025] A14. In step (2), The static aging conditions include a temperature of 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, a pressure of 0.2 MPa to 1.0 MPa, and a time of 1 hour to 8 hours, for example, 1 hour to 6 hours, or 2.5 hours to 6 hours; The conditions for the aging under stirring include a temperature of 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C; a pressure of 0.2 MPa to 1.0 MPa; a time of 1 hour to 6 hours, for example, 1 hour to 4.5 hours; and a stirring speed of 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm; Preferably, the ratio of the time of static aging to the time of aging under stirring is (1~5):1, for example, (1.1~3):1, (1.2~3):1, or (1.14~3):1, according to any one of the above technical solutions.

[0026] A15. The method for preparing pseudo-boehmite according to any one of the above technical solutions, wherein the washing conditions in step (3) are washing with deionized water at 70°C to 100°C, for example 75°C to 95°C, until the pH value of the wet filter cake reaches 7 to 7.5; the drying in step (3) is carried out at a drying temperature of 60°C to 98°C, for example 70°C to 98°C or 70°C to 95°C, and the drying time is not particularly limited, but is, for example, 1 hour to 10 hours, for example 3 hours to 4 hours.

[0027] A16. Use of pseudo-boehmite according to any one of the above technical solutions as a catalyst, carrier, and binder in the petroleum industry; as a carrier coating for automobile exhaust gas treatment catalysts in the automotive industry; as an additive to flame retardants in the firefighting field; as an ink-absorbing coating for high-quality inkjet printing paper in the papermaking industry; as a gas purification adsorbent, a defluorinator for drinking water, and an industrial wastewater decolorizer / deodorizer in the environmental protection industry; as an additive to coatings in the construction industry; and as a reinforcing agent in ceramic composites.

[0028] A17. The method includes forming an acidic slurry (for example, the pH value of the acidic slurry is preferably 1.5-2.6) from the pseudo-boehmite, molecular sieve, binder, clay and water according to any one of the above technical solutions, and spray-drying the slurry; The catalytic cracking catalyst has a most probable pore diameter of 3.5 nm to 4 nm and 4.5 nm to 10 nm (for example, 5.1 nm to 10 nm, or 5.1 nm to 7.5 nm).

[0029] A18. Slurrying the pseudo-boehmite according to any one of the above technical solutions with water to form a pseudo-boehmite slurry with a solid content of preferably 5-25% by weight, and adding hydrochloric acid, which may have a concentration of 10-37% by weight, so that the mass ratio of HCl to pseudo-boehmite, calculated as alumina, is preferably 0.037-0.104; The method for preparing a catalytic cracking catalyst according to any one of the above technical solutions, characterized in that it includes the steps of: mixing the pseudo-boehmite slurry with molecular sieves, binders, clay and water to obtain a colloidal slurry preferably having a solid content of 20-40 wt%, spray drying, and optionally washing and drying.

[0030] A19. A catalytic cracking catalyst, based on 100% by weight of the catalyst, comprising 10% to 50% by weight of molecular sieve on a dry basis, 10% to 40% by weight of pseudo-boehmite according to any one of the above technical solutions on an alumina basis, 3% to 20% by weight of binder on an oxide basis, and 10% to 80% by weight of clay on a dry basis; Preferably, the catalytic cracking catalyst has a most probable pore diameter of 3.5 nm to 4 nm and 4.5 nm to 10 nm (for example, 5.1 nm to 10 nm, or 5.1 nm to 7.5 nm), and / or The catalytic cracking catalyst, wherein the molecular sieve is, for example, one or more of a Y-type molecular sieve, a molecular sieve having an MFI structure, a non-zeolitic molecular sieve, and a molecular sieve having a BEA structure.

[0031] A20. A catalytic cracking catalyst, based on 100% by weight of the catalyst, comprising 10% to 50% by weight on a dry basis of a Y-type molecular sieve, 0% to 40% by weight on a dry basis of another molecular sieve, 10% to 40% by weight on an alumina basis of the pseudo-boehmite according to any one of the above technical solutions, 3% to 20% by weight on an oxide basis of a binder, and 10% to 80% by weight on a dry basis of clay; Preferably, the other molecular sieve is one or more of a zeolite having an MFI structure, a beta zeolite and a non-zeolitic molecular sieve, more preferably, the other molecular sieve is one or more of HZSM-5, ZRP and ZSP; and / or Preferably, the Y-type molecular sieve is one or more of REY, REHY, DASY, SOY, PSRY, HSY and HRY.

[0032] A21. A catalytic cracking method comprising a step of contacting and reacting heavy oil with a catalytic cracking catalyst under FCC conditions, wherein the catalytic cracking catalyst is a catalytic cracking catalyst described in any one of the above technical solutions or a catalytic cracking catalyst obtained by a method for preparing a catalytic cracking catalyst described in any one of the above technical solutions, for example, the FCC conditions include a reaction temperature of 480°C to 530°C, a reaction time of 1 second to 10 seconds, and a catalyst-to-oil ratio of 3 to 20:1 by weight.

[0033] [Technical solution B] B1. A method for producing a pseudo-boehmite having a high surface hydroxyl group content, a molecular sieve, a binder, clay, and water, and then spray-drying the resulting slurry; 3000~3800 is 6.0cm -1 mg -1 ~8.5cm -1 mg -1 and I 3000~3800 is 3000cm -1 ~3800cm -1 represents the infrared absorption intensity of the surface hydroxyl groups of pseudoboehmite in the infrared wavelength range of 3000~3800 The calculation method is 3000cm for the mass of the sample. -1 ~3800cm -1 the most probable pore diameter of the pseudo-boehmite rich in surface hydroxyl groups is greater than 4.5 nm and not more than 12 nm, and the most probable pore diameter of the catalytic cracking catalyst is 3.5 nm to 4 nm and 4.5 nm to 10 nm.

[0034] B2. The most probable pore diameter of the pseudo-boehmite rich in surface hydroxyl groups is 4.8 nm to 11 nm, for example 5 nm to 10 nm; the pH value of the acidic slurry is preferably 1.5 to 2.6; In one embodiment, the crystal size of the pseudo-boehmite rich in surface hydroxyl groups is D (130) = 4 nm to 10 nm, preferably 5 nm to 8.5 nm, and D (130) / D (020) is 1.0 to 1.5, preferably 1.1 to 1.3; In one embodiment, the pseudo-boehmite rich in surface hydroxyl groups has a crystallinity of 85% to 110%, preferably 88% to 108%, a peptization index of 90% to 100%, for example 93% to 99%, and a pore volume of 0.3 cm 3 / g to 0.58 cm 3 / g, for example 0.31 cm 3 / g to 0.52 cm 3 / g, and the method according to technical solution B1 is characterized in that.

[0035] B3. The method according to technical solution B1 is characterized in that the preparation method of the pseudo-boehmite rich in surface hydroxyl groups includes the following steps: (1) A step of reacting a sodium aluminate solution with CO2 to form a first slurry; (2) A step of aging the first slurry under certain conditions and adding a hydroxyl group regulator during the aging process to obtain an aged slurry, where the hydroxyl group regulator is urea and / or aqueous ammonia, and the aging temperature is 100 °C or higher and 185 °C or lower; preferably, the aging under the certain conditions is first static aging and then aging with stirring; (3) A step of filtering, washing, and drying the aged slurry.

[0036] B4. In step (1), the pH value at the reaction end point of the sodium aluminate solution with CO2 is 8.5 to 10.5, and the Al2O3 concentration of the sodium aluminate solution is 5 g / L to 60 g / L; The method according to technical solution B3, characterized in that in step (1), the reaction conditions of the sodium aluminate solution with CO2 include: introducing a CO2-containing gas having a CO2 concentration of 20-100 vol%, for example 40-80 vol%, into the sodium aluminate solution to react; the reaction starting temperature is preferably 10°C-35°C; and the reaction end temperature is preferably 15°C-55°C.

[0037] B5. The method according to technical solution B3 or B4, characterized in that in step (2), the slurry aging temperature is 100℃-185℃, the aging pressure is 0.2MPa-1MPa, and the aging time is 2 hours-10 hours.

[0038] B6. The method according to technical solution B3 or B5, characterized in that in step (2), the time for static aging is 1 hour to 4 hours, for example, 2 hours to 3 hours, the time for aging under stirring is 1 hour to 6 hours, and the stirring speed for the aging under stirring may be 50 r / min to 400 r / min.

[0039] B7. The method according to any one of technical solutions B3 to B7, characterized in that the aging temperature is 120℃-160℃, and the aging is preferably isothermal aging.

[0040] B8. The method according to any one of technical solutions B3 to B8, characterized in that the hydroxyl group modifier is added after a certain period of static aging and before aging under stirring, for example, during static aging, or after static aging ends and before aging under stirring begins; the hydroxyl group modifier is 0.5-2 wt% of the first slurry calculated as alumina; and the concentration of ammonia in the ammonia water is preferably 15-25 wt%.

[0041] B9. The method for preparing the catalytic cracking catalyst comprises: (1) slurrying the pseudo-boehmite rich in surface hydroxyl groups with water to form a pseudo-boehmite slurry preferably having a solid content of 5-25 wt %, and adding hydrochloric acid, which may have a concentration of 10-37 wt %, so that the mass ratio of HCl to the pseudo-boehmite rich in surface hydroxyl groups, calculated as alumina, is preferably 0.037-0.104; (2) The method according to technical solution B1, characterized in that it includes the steps of: mixing the pseudo-boehmite slurry with molecular sieves, binders, clay and water to obtain a colloidal slurry, preferably with a solid content of 20-40% by weight, spray drying, and optionally washing and drying.

[0042] B10. A catalytic cracking catalyst comprising 10% to 50% by weight on a dry basis of a molecular sieve, 10% to 40% by weight on an alumina basis of the pseudo-boehmite rich in surface hydroxyl groups, 3% to 20% by weight on an oxide basis of a binder, and 10% to 80% by weight on a dry basis of clay.

[0043] B11. The catalytic cracking catalyst according to technical solution B10, characterized in that the most probable pore size of the catalytic cracking catalyst is 3.5nm-4nm and 4.5nm-10nm; and the molecular sieve is, for example, one or more of a Y-type molecular sieve, a molecular sieve having an MFI structure, a non-zeolite molecular sieve, and a molecular sieve having a BEA structure.

[0044] B12. A catalytic cracking method comprising a step of contacting and reacting heavy oil with a catalytic cracking catalyst under FCC conditions, wherein the catalytic cracking catalyst is a catalytic cracking catalyst prepared by the method for preparing a catalytic cracking catalyst described in any one of Technical Solutions B1 to B9, or a catalytic cracking catalyst described in any one of Technical Solutions B10 to B11, and the FCC conditions are, for example, a reaction temperature of 480°C to 530°C, a reaction time of 1 to 10 seconds, and a catalyst-to-oil ratio by weight of 3 to 20:1.

[0045] (Technical solution C) C1. Mesoporous pseudo-boehmite rich in surface hydroxyl groups, wherein the pseudo-boehmite has a most probable pore diameter greater than 4.5 nm and less than or equal to 12 nm; 3000~3800 is 6.0cm -1 mg -1 ~8.5cm -1 mg -1で Yes, I 3000~3800 is 3000cm -1 ~3800cm -1 represents the infrared absorption intensity of the surface hydroxyl group of the pseudo-boehmite in the infrared wavelength range of I 3000~3800 The calculation method is 3000cm for the mass of the sample. -1 ~3800cm -1 The ratio of the absorption peak areas of the sample in the range of

[0046] C2. The pseudo-boehmite according to technical solution C1, characterized in that the pseudo-boehmite preferably has a most probable pore diameter of 4.8 nm to 11 nm, for example, 5 nm to 10 nm.

[0047] C3. The crystal size of the pseudoboehmite is D (130) = 4 nm to 10 nm, preferably 5 nm to 8.5 nm; D (130) / D (020) is 1.0 to 1.5, and preferably the D (130) / D (020) The pseudo-boehmite according to technical solution C1 or C2, characterized in that is 1.1 to 1.3.

[0048] C4. The crystallinity of the pseudo-boehmite is 85% to 110%, preferably 88% to 108%, the peptization index of the pseudo-boehmite is 90% to 100%, for example, the peptization index is 93% to 99%, and the pore volume of the pseudo-boehmite is 0.3 cm 3 / g~0.58cm 3 / g, for example, 0.31 cm 3 / g~0.52cm 3 / g.

[0049] C5. A method for preparing pseudoboehmite, comprising the following steps: (1) reacting a sodium aluminate solution with CO2 to form a first slurry; (2) aging the first slurry under certain conditions, adding a hydroxyl group modifier during the aging process to obtain an aged slurry, wherein the hydroxyl group modifier is urea and / or aqueous ammonia, and the aging temperature is 100°C or higher and 185°C or lower; preferably, the aging under certain conditions is performed by first static aging and then stirring; (3) filtering, washing, and drying the aged slurry;

[0050] C6. The method according to technical solution C5, wherein in step (1), the pH value of the sodium aluminate solution at the end of the reaction with CO2 is 8.5-10.5, and the Al2O3 concentration of the sodium aluminate solution is 5g / L-60g / L.

[0051] C7. The method according to technical solution C5 or C6, characterized in that in step (1), the reaction conditions of the sodium aluminate solution with CO2 include: introducing a CO2-containing gas having a CO2 concentration of 20-100% by volume into the sodium aluminate solution to react, wherein the reaction starting temperature is 10°C-35°C, and the reaction end temperature is preferably 15°C-55°C.

[0052] C8. The method according to technical solution C5, C6 or C7, characterized in that in step (2), the aging temperature of the slurry is 100°C to 185°C, the aging pressure is 0.2MPa to 1MPa, and the aging time is 2 hours to 10 hours.

[0053] C9. The method according to technical solution C5 or C8, characterized in that in step (2), the time for static aging is 1 hour to 4 hours, for example, 2 hours to 3 hours, the time for aging under stirring is 1 hour to 6 hours, and the stirring speed for the aging under stirring may be 50 r / min to 400 r / min.

[0054] C10. The method according to technical solution C5, C6, C7, C8 or C9, characterized in that the aging temperature is 120℃-160℃, and the aging is preferably isothermal aging.

[0055] C11. The method according to any one of technical solutions C5 to C10, characterized in that the hydroxyl group modifier is added after static aging for a certain period of time and before aging under stirring, for example, during the static aging process, or after static aging is completed and before aging under stirring is started; the hydroxyl group modifier is 0.5-2 wt% of the first slurry calculated as alumina; and the concentration of ammonia in the ammonia water is preferably 15-25 wt%.

[0056] C12. Use of pseudo-boehmite according to any one of technical solutions C1 to C4 in the preparation of a catalyst.

[0057] [Detailed explanation] In this specification, unless otherwise specified, pressure refers to gauge pressure.

[0058] In this specification, unless otherwise specified, the content means a value based on weight %.

[0059] In this specification, sodium aluminate and sodium metaaluminate are synonymous and both refer to NaAlO2.

[0060] The present invention provides a method for producing a porous membrane comprising: a porous membrane having a most probable pore diameter of greater than 4.5 nm and less than or equal to 12 nm; and / or 3000~3800 is 6.0cm -1 mg -1 ~8.5cm -1 mg-1 It is pseudoboehmite, and I 3000~3800 is 3000cm -1 ~3800cm -1 represents the infrared absorption intensity of the surface hydroxyl groups of pseudo-boehmite in the infrared wavelength range of 3000~3800 The calculation method is 3000cm for the mass of the sample (unit: mg). -1 ~3800cm -1 The area of ​​the absorption peak of the sample in the range (unit: cm -1 ) ratio to provide pseudoboehmite.

[0061] Preferably, the pseudo-boehmite provided in the present invention has a crystal size D (130) is 4 nm to 10 nm, for example, greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm.

[0062] Preferably, the pseudo-boehmite provided in the present invention is D (130) / D (020) = 1.0 to 1.5, for example, 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26. The pseudo-boehmite can maintain a relatively large most probable pore diameter even after acidification.

[0063] D (130) represents the crystal size of the crystal plane represented by the (130) peak (corresponding to 2θ = 38.3°) in the XRD spectrum of pseudoboehmite crystals.

[0064] D (020)は represents the crystal size of the crystal plane represented by the (020) peak (corresponding to 2θ = 14.1°) in the XRD spectrum of pseudoboehmite crystals.

[0065] The crystal size D was measured by powder X-ray diffraction (XRD) and calculated using the Scherrer equation

number

number

number

[0066] The pseudo-boehmite provided by the present invention has a most probable pore diameter of greater than 4.5 nm and less than or equal to 12 nm, for example, 4.8 nm to 11 nm, 5 nm to 10 nm, 5.5 nm to 9 nm, 6 nm to 8.5 nm, 7 nm to 9 nm, 5.2 nm to 7.6 nm, or 5.2 nm to 7.5 nm. The pore diameter refers to the diameter of the pores.

[0067] The pseudo-boehmite provided in the present invention has a crystallinity of 85% to 110%, for example, 88% to 108%, 90% to 105%, or 92% to 103%.

[0068] The pseudo-boehmite provided in the present invention has a particle size of 0.3 cm 3 / g~0.58cm 3 / g, e.g., 0.31 cm 3 / g~0.52cm 3 / g, 0.33cm 3 / g~0.5cm 3 / g, or 0.34 cm 3 / g~0.46cm 3 / g pore volume.

[0069] The pseudo-boehmite provided by the present invention has a particle size of 6.0 cm -1 mg -1 ~8.5cm -1 mg -1 , e.g., 6.2 cm -1 mg -1 ~8.3cm -1 mg -1 I 3000~3800 It has.

[0070] The pseudo-boehmite provided in the present invention has a peptization index of 90% to 100%, for example, 93% to 99%, or 94% to 98%.

[0071] The present invention provides a method for preparing pseudo-boehmite, comprising the following steps: (1) reacting a sodium (meta)aluminate solution with CO to form a first slurry; preferably, the molar ratio of the two, calculated as NaAlO and CO, is in the range of 0.5 to 2 times the theoretical equivalent ratio, e.g., 0.833 to 1.2 times, or 0.9 to 1.1 times, i.e., when the theoretical equivalent ratio is 2:1, the actual molar ratio of the two is (1-4):1, e.g., (1.67-2.4):1, or (1.8-2.2):1. (2) Aging the first slurry under certain conditions, adding a hydroxyl group modifier during the aging process to obtain an aged slurry called the second slurry, where the hydroxyl group modifier is a precursor capable of forming aqueous ammonia and / or NH3 (e.g., urea, etc.), and the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C; preferably, the aging under certain conditions is: first, static aging, and then aging under stirring; (3) filtering, washing, and drying the aged slurry;

[0072] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the concentration of the sodium (meta)aluminate solution may be 5 g / L to 60 g / L, for example, 8 g / L to 45 g / L, calculated as Al2O3.

[0073] The sodium (meta)aluminate solution may be commercially available or prepared according to conventional methods. In one embodiment, the method for preparing the sodium (meta)aluminate solution includes the steps of reacting aluminum hydroxide with an alkaline solution at a temperature of 90°C to 120°C for 1 to 4 hours, and diluting the solution to an Al2O3 concentration of 5 g / L to 60 g / L, for example, 8 g / L to 45 g / L. The alkaline solution is, for example, an aqueous sodium hydroxide solution. The caustic ratio (molar ratio of sodium oxide to aluminum oxide) of the sodium (meta)aluminate solution is, for example, 1.0 to 3.2.

[0074] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the sodium (meta)aluminate solution may be reacted with CO by contacting it with CO, and the CO-containing gas may be introduced into the sodium (meta)aluminate solution. The volume concentration of CO in the CO-containing gas is 20 to 100% by volume, for example, 40 to 100% by volume, 30 to 90% by volume, or 40 to 80% by volume. The remainder is an inert gas such as nitrogen.

[0075] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the pH value of the sodium (meta)aluminate solution at the end of the reaction with CO2 is 8.5 to 10.5, for example, 9.2 to 10.3.

[0076] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the reaction may start at a temperature of 10°C to 35°C, and the reaction may end at a temperature of 15°C to 55°C.

[0077] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the sodium (meta)aluminate solution is brought into contact with CO2 to react, and the reaction time of the sodium (meta)aluminate solution with CO2 can be 20 to 70 minutes.

[0078] According to the method for preparing pseudo-boehmite of the present invention, in step (1), the reaction conditions of the sodium (meta)aluminate solution with CO may include a reaction initiation temperature of 10°C to 35°C, a reaction end temperature of 15°C to 55°C, and a reaction time of 20 to 70 minutes. The pH value of the sodium (meta)aluminate solution at the end of the reaction with CO is 8.5 to 10.5, for example, 9.2 to 10.3; the sodium (meta)aluminate solution reacts with CO; and the sodium (meta)aluminate solution is contacted with a CO2-containing gas having a volume concentration of CO2 of 20 to 100% by volume, for example, 40 to 100% by volume, 30 to 90% by volume, or 40 to 80% by volume, and the remainder is an inert gas such as nitrogen.

[0079] In step (2), the aging under certain conditions is preferably carried out as follows: first, static aging is carried out, and then aging is carried out under stirring. The pseudo-boehmite obtained by this method has a crystal size D (130) = 4 nm to 10 nm, for example, greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm, and D (130) / D (020) is 1.0 to 1.5, for example, 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26, and may have a relatively large most probable pore diameter.

[0080] In step (2), the first slurry is aged under certain conditions. In one embodiment, the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C. The first slurry may be heated to 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, and then aged at that temperature. For example, the time required to raise the temperature of the first slurry from the reaction end temperature to the aging temperature is 60 minutes or less. Isothermal aging may be performed by maintaining a constant temperature from the start to the end of the aging. Isothermal aging refers to controlling the temperature of static aging and aging under stirring to a constant value, and for example, the temperature difference between static aging and aging under stirring is preferably 2°C or less.

[0081] In step (2), the ripening pressure may be 0.2 MPa to 1.0 MPa.

[0082] In step (2), the stirring speed may be controlled to 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm. A conventional stirring method may be used for stirring. The stirring causes the aged slurry to be driven by the stirring blades and agitated in the aging vessel.

[0083] In step (2), the maturation time may be 2 hours to 11.5 hours, for example, 2 hours to 10 hours, or 3.5 hours to 10.5 hours.

[0084] In step (2), the slurry is first aged at a constant temperature, and then aged under stirring. In static aging, the slurry may be left standing without stirring during aging, for example, for a fixed period of time. For example, the first slurry is first aged at the aging temperature for 1 to 8 hours, e.g., 1 to 6 hours, 2.5 to 6 hours, 1 to 4 hours, or 2 to 3 hours, and then stirred and aged at the aging temperature for 1 to 6 hours, e.g., 1 to 4.5 hours. The stirring speed may be 50 rpm to 450 rpm, e.g., 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm.

[0085] In step (2), in one embodiment, the first slurry is aged under certain conditions, the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, the aging pressure is 0.2MPa to 1.0MPa, and the aging is performed at the certain temperature for 2 hours to 11.5 hours, for example, 2 hours to 10 hours or 3.5 hours to 10.5 hours. Here, the first slurry is first statically aged for 1 hour to 8 hours, for example, 1 hour to 6 hours, 2.5 hours to 6 hours, 1 hour to 4 hours, or 2 hours to 3 hours, and then stirred while maintaining the aging temperature and aging pressure, controlling the stirring speed to 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm, and the stirring aging time is 1 hour to 6 hours, for example, 1 hour to 4.5 hours.

[0086] In step (2), a hydroxyl group regulator is added, and the hydroxyl group regulator may be ammonia water and / or a precursor capable of forming NH3, such as urea. The amount of the hydroxyl group regulator added is 0.5 to 2 wt %, for example, 0.7 to 1.8 wt %, of the alumina content in the pseudo-boehmite. The concentration of the ammonia water (calculated as NH3) is 15 to 25 wt %, for example, 20 wt %.

[0087] In one embodiment, the hydroxyl group regulator is added after the reaction with CO in step (1) has stopped and before aging under agitation. For example, the hydroxyl group regulator is added before static aging, during static aging, after a certain period of static aging and before aging under agitation, or after static aging has ended and before aging under agitation has started, or a combination thereof. Typically, the hydroxyl group regulator is added after a certain period of static aging, for example, during static aging, or after static aging has ended and before aging under agitation has started.

[0088] In step (3), the aged slurry is filtered, washed, and dried to obtain macroporous pseudo-boehmite rich in surface hydroxyl groups and having a specific most probable pore size distribution. In one embodiment, the washing conditions are to wash with deionized water at 70°C to 100°C, e.g., 75°C to 95°C, until the pH of the wet filter cake reaches 7 to 7.5. The drying temperature may be 60°C to 98°C, e.g., 70°C to 98°C or 70°C to 95°C. The drying time is not particularly limited, but may be, for example, 1 hour to 10 hours, e.g., 2 hours to 4 hours, or 3 hours to 4 hours.

[0089] After static aging and subsequent aging under stirring, pseudoboehmite with specific crystal characteristics can be obtained. Its crystal size D (130) is 4 nm to 10 nm, for example, greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm, and D (130) / D (020) = 1.0 to 1.5, for example 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26.

[0090] The pseudo-boehmite provided by the present invention has abundant surface hydroxyl groups, a relatively large probable pore size, a relatively high crystallinity, and good peptization properties. Because the pseudo-boehmite provided by the present invention has good binding properties, it can be used in catalytic cracking catalysts to reduce coke selectivity in the conversion of hydrocarbon oils.

[0091] The method for preparing pseudo-boehmite provided by the present invention is green, environmentally friendly, low-cost, and easy to implement, thereby filling the technical gap for carbonization-based production of pseudo-boehmite suitable for catalytic cracking catalysts, and thereby enabling the production of pseudo-boehmite with better binding performance, higher most probable pore size distribution, high crystallinity, large crystal size, specific crystal structure, and good peptization properties.

[0092] The pseudo-boehmite provided by the present invention can be used to prepare catalysts; the catalyst obtained after acidification can have a larger probable pore size and better strength.For example, when used to prepare catalytic cracking catalysts, the pseudo-boehmite can be directly acidified without pore enlargement treatment to obtain catalytic cracking catalysts with a larger probable pore size, for example, a probable pore size greater than 5 nm, and better attrition resistance.

[0093] Compared with conventional pseudoboehmite, the pseudoboehmite of the present invention can be used to prepare catalytic cracking catalysts with a more mesoporous structure and a larger most probable pore size, resulting in better catalytic strength (lower wear index). The resulting catalytic cracking catalysts have lower coke selectivity and better product distribution, which can improve the yields of, for example, liquefied gas and gasoline.

[0094] The present invention provides a method for preparing a catalytic cracking catalyst, comprising: The method includes the steps of forming an acidic slurry having a pH value of preferably 1.5 to 2.6 from the pseudo-boehmite rich in surface hydroxyl groups of the present invention, a molecular sieve, a binder, clay and water, followed by spray drying; Pseudoboehmite rich in surface hydroxyl groups I. 3000~3800 is 6.0cm -1 mg -1 ~8.5cm -1 mg -1 , e.g. 6.2cm -1 mg -1 ~8.3cm -1 mg -1 and I 3000~3800 is 3000cm -1 ~3800cm -1 represents the infrared absorption intensity of the surface hydroxyl groups of pseudoboehmite in the infrared wavelength range of 3000~3800 The calculation method is 3000cm for the mass of the sample (unit: mg). -1 ~3800cm -1 The area of ​​the absorption peak of the sample in the range (unit: cm -1 The most probable pore diameter of the pseudo-boehmite rich in surface hydroxyl groups is greater than 4.5 nm and not greater than 12 nm, e.g., 4.8 to 11 nm, 5 to 10 nm, 5.5 to 9 nm, 6 to 8.5 nm, 7 to 9 nm, 5.2 to 7.6 nm, or 5.2 to 7.5 nm, and the most probable pore diameter of the catalytic cracking catalyst may be 3.5 to 4 nm and 4.5 to 10 nm (e.g., 5.1 to 10 nm or 5.1 to 7.5 nm). In this specification, the most probable pore diameter refers to the diameter of the pores.

[0095] In one embodiment, the pseudo-boehmite rich in surface hydroxyl groups has a crystal size D of 4 nm to 10 nm, e.g., greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm. (130) It has.

[0096] In one embodiment, the pseudoboehmite is rich in surface hydroxyl groups. (130) / D (020) = 1.0 to 1.5, for example, 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26.

[0097] D (130) indicates the crystal size of the crystal plane represented by the (130) peak (corresponding to 2θ = 38.3°) in the XRD spectrum of pseudoboehmite crystals.

[0098] D (020)indicates the crystal size of the crystal plane represented by the (020) peak (corresponding to 2θ=14.1°) in the XRD spectrum of pseudoboehmite crystals.

[0099] The crystal size D was measured by powder X-ray diffraction (XRD) and the Scherrer equation

number

number

number

[0100] In one embodiment, the pseudo-boehmite rich in surface hydroxyl groups has a crystallinity of 85% to 110%, for example, 88% to 108%, 90% to 105%, or 92% to 103%.

[0101] In one embodiment, the pore volume of the pseudo-boehmite rich in surface hydroxyl groups is 0.3 cm 3 / g~0.58cm 3 / g, e.g., 0.31 cm 3 / g~0.52cm 3 / g, 0.33cm 3 / g~0.5cm 3 / g, or 0.34 cm3 / g~0.46cm 3 / g.

[0102] In one embodiment, the peptization index of the pseudo-boehmite rich in surface hydroxyl groups is 90% to 100%, for example, 93% to 99%, or 94% to 98%.

[0103] The pseudo-boehmite of the present invention, which is rich in surface hydroxyl groups, can maintain a relatively large pore size even after acidification, and is therefore suitable for reducing the coke yield and improving the yield of gasoline and liquefied gas.

[0104] In one embodiment, a method for preparing pseudo-boehmite rich in surface hydroxyl groups comprises the steps of: (1) reacting a sodium (meta)aluminate solution with CO to form a first slurry; preferably, the molar ratio of the two, calculated as NaAlO and CO, is in the range of 0.5 to 2 times the theoretical equivalent ratio, e.g., 0.833 to 1.2 times, or 0.9 to 1.1 times, i.e., when the theoretical equivalent ratio is 2:1, the actual molar ratio of the two is (1 to 4):1, e.g., (1.67 to 2.4):1, or (1.8 to 2.2):1; (2) aging the first slurry under certain conditions, adding a hydroxyl group modifier during the aging process to obtain an aged slurry, where the hydroxyl group modifier is a precursor capable of forming ammonia water and / or NH3, such as urea, and the aged slurry is called a second slurry, and the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C; preferably, the aging under certain conditions refers to first static aging and then aging under stirring; (3) filtering, washing, and drying the aged slurry;

[0105] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (1), the concentration of the sodium (meta)aluminate solution may be 5 g / L to 60 g / L, for example, 8 g / L to 45 g / L, calculated as Al2O3.

[0106] The sodium (meta)aluminate solution may be commercially available or prepared according to conventional methods. In one embodiment, the method for preparing the sodium (meta)aluminate solution includes the steps of reacting aluminum hydroxide with an alkaline solution at a temperature of 90°C to 120°C for 1 hour to 4 hours, and diluting the solution to an Al2O3 concentration of 5 g / L to 60 g / L, for example, 8 g / L to 45 g / L. The alkaline solution is, for example, an aqueous sodium hydroxide solution. The caustic ratio (molar ratio of sodium oxide to aluminum oxide) of the sodium (meta)aluminate solution is, for example, 1.0 to 3.2.

[0107] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (1), a sodium (meta)aluminate solution is brought into contact with CO2 to react with it, and the reaction may be carried out by introducing a CO2-containing gas into the sodium (meta)aluminate solution, wherein the volume concentration of CO2 in the CO2-containing gas is 20 to 100% by volume, for example, 40 to 100% by volume, 30 to 90% by volume, or 40 to 80% by volume, with the remainder being an inert gas such as nitrogen.

[0108] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, the pH value of the sodium (meta)aluminate solution at the end of the reaction with CO2 is 8.5 to 10.5, for example, 9.2 to 10.3.

[0109] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (1), the reaction may start at a temperature of 10°C to 35°C, and the reaction may end at a temperature of 15°C to 55°C.

[0110] According to the method for preparing pseudo-boehmite having abundant surface hydroxyl groups of the present invention, in step (1), a sodium (meta)aluminate solution is contacted with CO for reaction, where the reaction time of the sodium (meta)aluminate solution with CO may be 20 to 70 minutes.

[0111] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (1), the reaction conditions of the sodium (meta)aluminate solution with CO may include a reaction initiation temperature of 10°C to 35°C, a reaction end temperature of 15°C to 55°C, and a reaction time of 20 to 70 minutes. The pH value of the sodium (meta)aluminate solution at the end of the reaction with CO is 8.5 to 10.5, for example, 9.2 to 10.3; the sodium (meta)aluminate solution is reacted with CO by contacting the sodium (meta)aluminate solution with a CO2-containing gas having a volume concentration of 20 to 100% by volume, for example, 40 to 100% by volume, 30 to 90% by volume, or 40 to 80% by volume, with the remainder being an inert gas such as nitrogen.

[0112] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (2), the aging under certain conditions is first performed by static aging, and then by aging under stirring. The pseudo-boehmite obtained by this method has a crystal size D (130) = 4 nm to 10 nm, for example, greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm, and D (130) / D (020) The attrition index may be 1.0 to 1.5, e.g., 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26, and the catalyst may have a larger most probable pore diameter. Catalysts prepared by acidifying the attrition index may have a lower attrition index and a larger most probable pore diameter.

[0113] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (2), the first slurry is aged under certain conditions. In one embodiment, the aging temperature is 100°C to 185°C, for example, 100°C to 185°C, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C. The first slurry may be heated to 100°C to 185°C, for example, 100°C to 185°C, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, and then aged at that temperature. For example, the time required to raise the temperature of the first slurry from the reaction end temperature to the aging temperature is 60 minutes or less. Isothermal aging may be performed by maintaining a constant temperature from the start to the end of aging. Isothermal aging refers to controlling the temperature of static aging and aging under stirring to a constant value, and for example, the temperature difference between static aging and aging under stirring is preferably 2°C or less.

[0114] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, the aging pressure in step (2) may be 0.2 MPa to 1.0 MPa.

[0115] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (2), the stirring speed may be controlled to 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm. Stirring may be performed by a conventional stirring method. By stirring, the aged slurry is driven by a stirring blade and stirred in the aging vessel.

[0116] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, the maturation time in step (2) may be 2 hours to 11.5 hours, for example, 2 hours to 10 hours, or 3.5 hours to 10.5 hours.

[0117] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in step (2), the slurry is first aged at a constant temperature, and then aged under stirring. In static aging, the slurry may be left standing without stirring during aging, for example, by standing for a certain period of time. For example, the first slurry is first aged under the aging temperature for 1 to 8 hours, e.g., 1 to 6 hours, 2.5 to 6 hours, 1 to 4 hours, or 2 to 3 hours, and then aged under stirring under the aging temperature for 1 to 6 hours, e.g., 1 to 4.5 hours. The stirring speed may be 50 rpm to 450 rpm, e.g., 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm.

[0118] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in one embodiment, in step (2), the first slurry is aged under certain conditions, the aging temperature is 100°C to 185°C, for example, 100°C or higher and 185°C or lower, 120°C to 180°C, 135°C to 180°C, 120°C to 160°C, or 135°C to 160°C, and the aging pressure is 0.2MPa to 1.0MPa. The reaction at the certain temperature is carried out for 2 hours to 11.5 hours, for example, 2 hours to 10 hours or 3.5 hours to 10.5 hours to perform aging. Here, the first slurry is first statically aged for 1 hour to 8 hours, for example, 1 hour to 6 hours, 2.5 hours to 6 hours, 1 hour to 4 hours, or 2 hours to 3 hours, and then stirred while maintaining the aging temperature and aging pressure, controlling the stirring speed to 50 rpm to 450 rpm, for example, 50 rpm to 400 rpm, 60 rpm to 400 rpm, 120 rpm to 450 rpm, or 150 rpm to 450 rpm, and the stirring aging time is 1 hour to 6 hours, for example, 1 hour to 4.5 hours.

[0119] According to the method for preparing pseudo-boehmite having abundant surface hydroxyl groups of the present invention, in step (2), a hydroxyl group regulator is added. The hydroxyl group regulator may be ammonia water and / or a precursor capable of forming NH3, such as urea. The amount of the hydroxyl group regulator added is 0.5 to 2 wt %, for example, 0.7 to 1.8 wt %, of the alumina in the pseudo-boehmite. The concentration of the ammonia water (calculated as NH3) is 15 to 25 wt %, for example, 20 wt %.

[0120] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, in one embodiment, the hydroxyl group regulator is added after the completion of the reaction with CO in step (1) and before aging under stirring. For example, the hydroxyl group regulator is added before static aging, during static aging, after a certain period of static aging and before aging under stirring, or after the completion of static aging and before the start of aging under stirring, or a combination thereof. Typically, the hydroxyl group regulator is added after a certain period of static aging, for example, during static aging, or after the completion of static aging and before the start of aging under stirring.

[0121] According to the method for preparing pseudo-boehmite rich in surface hydroxyl groups of the present invention, the aged slurry is filtered, washed, and dried in step (3) to obtain macroporous pseudo-boehmite rich in surface hydroxyl groups and having a specific most probable pore size distribution. In one embodiment, the washing conditions are washing with deionized water at 70°C to 100°C, for example, 75°C to 95°C, until the pH of the wet filter cake reaches 7 to 7.5. The drying temperature is preferably 60°C to 98°C, for example, 70°C to 98°C or 70°C to 95°C. The drying time is not particularly limited, but is, for example, 1 hour to 10 hours, for example, 2 hours to 4 hours, or 3 hours to 4 hours.

[0122] The pseudo-boehmite obtained by the method for preparing pseudo-boehmite rich in surface hydroxyl groups has abundant surface hydroxyl groups, a larger probable pore size, a higher crystallinity, good peptization properties, and good binding ability even after acidification. After static aging and subsequent aging under stirring, pseudo-boehmite rich in surface hydroxyl groups with specific crystal properties can be obtained. Its crystal size D (130)is 4 nm to 10 nm, for example, greater than 4 nm to 10 nm, 4.5 nm to 9 nm, 5 nm to 8.5 nm, 5.1 nm to 8.5 nm, 5.5 nm to 8.5 nm, 6 nm to 8.2 nm, or 5.0 nm to 7.9 nm, and D (130) / D (020) = 1.0 to 1.5, for example, 1.1 to 1.4, 1.2 to 1.35, 1.1 to 1.3, or 1.13 to 1.26. By using the pseudo-boehmite in a catalytic cracking catalyst, the coke selectivity in the conversion of hydrocarbon oil can be reduced, and the wear index of the catalytic cracking catalyst can be lowered.

[0123] The method for preparing a catalytic cracking catalyst provided by the present invention includes forming a slurry of pseudoboehmite, molecular sieve, alumina binder, clay, and water, spray-drying the slurry, and optionally washing and drying. Conventional techniques can be used for spray-drying, washing, and drying, and no special requirements are required for the present invention. The catalyst can be prepared according to conventional methods, such as those disclosed in Patent Publications CN1098130A and CN1362472A.

[0124] The catalytic cracking catalyst provided by the present invention comprises, based on 100 wt% of the catalyst, 10 wt% to 50 wt%, for example 20 wt% to 45 wt%, on a dry basis, of a molecular sieve; 10 wt% to 40 wt%, for example 15 wt% to 35 wt%, on an alumina basis, of a pseudo-boehmite rich in surface hydroxyl groups; 3 wt% to 20 wt% on an oxide basis of a binder; and 10 wt% to 80 wt%, for example 20 wt% to 50 wt%, on a dry basis, of a clay.

[0125] The catalytic cracking catalyst provided by the present invention comprises a molecular sieve, and the molecular sieve may be, for example, one or more of a Y-type molecular sieve, a zeolite having an MFI structure, a beta zeolite (also referred to herein as a "molecular sieve having a BEA structure"), or a non-zeolitic molecular sieve. In one embodiment, the molecular sieve comprises a Y-type molecular sieve and a molecular sieve other than the Y-type molecular sieve, and the content of the other molecular sieve is, for example, 0 to 40 wt%, e.g., 0 to 30 wt%, or 1 to 20 wt%, based on 100 wt% of the catalyst, on a dry basis. The other molecular sieve is selected from one or more molecular sieves used in catalytic cracking catalysts, such as a zeolite having an MFI structure, a beta zeolite, or a non-zeolitic molecular sieve. For example, based on 100% by weight of the catalyst, the content of the Y-type molecular sieve on a dry basis is 40% by weight or less, for example, 1 to 40% by weight or 30 to 38% by weight. The Y-type molecular sieve is, for example, one or more of REY, REHY, DASY, SOY, PSRY, and HRY zeolites. The zeolite having an MFI structure is, for example, one or more of HZSM-5, ZRP, and ZSP. The beta zeolite is, for example, Hβ. The non-zeolitic molecular sieve is, for example, one or more of aluminum phosphate molecular sieves (AlPO molecular sieves) and silicon aluminum phosphate molecular sieves (SAPO molecular sieves).

[0126] In the catalytic cracking catalyst provided by the present invention, the content of pseudo-boehmite rich in surface hydroxyl groups is 10 to 40% by weight, for example, 15 to 35% by weight, or 20 to 30% by weight, calculated on a dry basis.

[0127] In the catalytic cracking catalyst provided by the present invention, the binder is preferably an alumina binder, and the content of the alumina binder is 3 to 20% by weight, for example, 5 to 15% by weight, based on alumina. The alumina binder is preferably an alumina sol. For example, the catalytic cracking catalyst contains 3 to 20% by weight, for example, 5 to 15% by weight, or 3 to 15% by weight, based on alumina.

[0128] Preferably, the catalytic cracking catalyst has two most probable pore diameters, and the two most probable pore diameters are 3.5 nm to 4 nm and 4.5 nm to 10 nm (for example, 5.1 nm to 10 nm or 5.1 nm to 7.5 nm).

[0129] In the catalytic cracking catalyst provided by the present invention, the clay is selected from one or more clays used as components of cracking catalysts, such as kaolin, polyhydrate kaolin, halloysite, montmorillonite, diatomaceous earth, saponite, rectorite, sepiolite, attapulgite, hydrotalcite, and bentonite. These clays are well known to those skilled in the art. Preferably, the clay content in the catalytic cracking catalyst provided by the present invention is 20 to 55 wt. % or 30 to 50 wt. % on a dry basis.

[0130] The present invention further provides a catalytic cracking method comprising the step of contacting and reacting heavy oil with a catalytic cracking catalyst prepared by the method for preparing a catalytic cracking catalyst under FCC conditions, such as a reaction temperature of 480°C to 530°C, a reaction time of 1 to 10 seconds, and a catalyst-to-oil ratio of (3 to 20):1 by weight.

[0131] The catalytic cracking catalyst preparation method provided by the present invention uses pseudoboehmite rich in surface hydroxyl groups, and after acidification treatment, a catalytic cracking catalyst with a low wear index and good strength is obtained. In a preferred embodiment, by using pseudoboehmite rich in surface hydroxyl groups with specific crystal properties, the resulting catalytic cracking catalyst can have a pore structure larger than 5 nm and a lower coke selectivity. When using Y-type molecular sieves and ZSM-5 molecular sieves, the resulting catalytic cracking catalyst can have a better product distribution, for example, improving the yield of liquefied gas and gasoline.

[0132] The catalytic cracking catalyst preparation method provided by the present invention is suitable for preparing a catalytic cracking catalyst containing pseudoboehmite and having a most probable pore diameter of 3.5 nm to 4 nm and 4.5 nm to 10 nm (e.g., 5.1 nm to 10 nm or 5.1 nm to 7.5 nm). When the amount of pseudoboehmite and the amount of molecular sieve used are the same, the catalyst can have better attrition resistance. In particular, when the content of molecular sieve is high, for example, higher than 35 wt%, the catalyst can have a significantly reduced attrition index and a larger most probable pore diameter of mesopores compared to conventional catalysts with similar compositions.

[0133] [Example] The present invention will be further described below based on examples, but the present invention is not limited to these examples.

[0134] For the measurement of the performance parameters of pseudo-boehmite, reference can be made to YS / T1161 (analysis method for pseudo-boehmite).

[0135] In this application, the crystallinity and crystal size D of the samples were measured by powder X-ray diffraction (XRD) using the RIPP139-90, RIPP140-90, RIPP145-90, and RIPP146-90 standard methods (Yang Cuiding et al., eds., "Petrochemical Analysis Methods (RIPP Test Methods)", Scientific Press, 1990).

[0136] The crystallinity of the pseudoboehmite in the sample was calculated by measuring the integrated intensity at 2θ=38.3° (130 crystal plane) of the sample and the standard sample S87-16b using the external standard method. The standard sample was manufactured by the Petrochemical Research Institute and commercially available under the number S87-16b. After calibration, the pseudoboehmite crystallinity was 98.0%. The crystallinity of the sample was calculated using the following formula: Crystallinity = Net integral intensity of sample / Net integral intensity of standard sample × 98.0 The crystal size is calculated using the Scherrer formula

number

number

number

[0137] In this application, the most probable pore distribution and pore volume (pore volume) of a sample were determined by static volumetric adsorption using low-temperature nitrogen, the specific surface area and pore volume were calculated using the two-parameter BET equation, and the pore size distribution was calculated using the BJH equation. The pore size corresponding to the highest point on the pore size distribution curve was taken as the most probable pore size of the sample. Using an ASAP2405NV1.01 automatic adsorption apparatus manufactured by Micromeritics, USA, the sample was adsorbed at 1.33 × 10 ー2The samples were degassed under vacuum at 300°C for 4 h, and the adsorption / desorption isotherms were measured at 77.4 K using N2 as the adsorption medium.

[0138] In this application, the peptization index was measured according to the following procedure. 10 g of pseudo-boehmite was weighed and roasted at 600°C for 3 hours, then placed in a desiccator and cooled to room temperature. The weight was measured and found to be W0 g, so the dry basis a0 = W0 / 10. Pseudo-boehmite with a weight of m1 = 6 / a0 g was weighed out, and m1 g of the pseudo-boehmite was placed in a 100 mL polytetrafluoroethylene cup. Deionized water was added to the cup to bring the weight to 40 g. The mixture was uniformly stirred with a magnetic rotor, and then 20 mL of 0.19 N dilute nitric acid solution was added and magnetically stirred for 20 minutes. The entire solution was poured into a centrifuge tube and centrifuged at 1900 rpm for 20 minutes. The upper layer of the colloidal solution was poured into a pre-weighed crucible, dried at 80°C, roasted at 600°C for 3 hours, and then placed in a desiccator and cooled to room temperature. The weight was measured and found to be m2 g, so the peptization index DI = (m2 / 6) * 100%.

[0139] In this disclosure, I 3000~3800 The measurement method is as follows. A Fourier transform infrared spectrophotometer (for example, Nicolet 6700 model manufactured by Thermo Fisher, USA) is used to measure the infrared absorption intensity of the surface hydroxyl groups of the sample. The test conditions are as follows. After thoroughly crushing the sample, 10 mg to 20 mg of the sample is taken and pressed to form a self-supporting piece. After accurately weighing, the sample is transferred to the sample holder of the in-situ cell and subjected to vacuum treatment. The sample is crushed to a size of 1.0 × 10 -3 The sample was purified under high vacuum conditions of 100 Pa (absolute pressure) and a temperature of 450°C for 2 hours. After purification, the sample was cooled to room temperature and then quenched with 400 cm -1 ~4000cm -1 In the range of 4.0 cm -1The infrared absorption signal of the hydroxyl group was obtained by scanning at a resolution of 1000 sq. m. The absorption signal data was processed to obtain the infrared absorption spectrum of the hydroxyl group, with wavenumber as the abscissa and absorbance as the ordinate (absorbance: the logarithm to the base 10 of the ratio of the incident light intensity before the light passes through the material to the transmitted light intensity after the light passes through the material (i.e., lg(I0 / I1)), where I0 is the incident light intensity and I1 is the transmitted light intensity). 3000~3800 The calculation method is the ratio of the mass of the sample (unit: mg) to the 3000 cm -1 ~3800cm -1 The area (unit: cm) of the infrared absorption peak of the surface hydroxyl groups of pseudoboehmite in the infrared wavelength range of -1 ) is the ratio of

[0140] In the examples, analytical grade sodium metaaluminate with a caustic ratio of 1, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., was used.

[0141] Example 1 A sodium metaaluminate solution with a concentration of 20 g / L Al2O3 was reacted with 40% carbon dioxide gas (volume fraction: 40% carbon dioxide, remainder: nitrogen) to form a gel while controlling the pH at the end of the reaction to 9.5. The resulting slurry was transferred to an aging vessel and aged for 3 hours at 135 °C and 0.35 MPa. 0.8 wt% urea (based on the weight of the slurry calculated based on the mass of alumina) was added. While maintaining the temperature and pressure conditions, stirring was initiated and the stirring speed was maintained at 150 rpm, allowing the mixture to age for 1 hour. After aging, the resulting slurry was subjected to solid-liquid separation and washed with deionized water at 85 °C for 30 minutes until the pH of the wet filter cake reached 7.1, yielding a pseudoboehmite wet filter cake with impurities removed. The wet filter cake was dried at 80 °C for 3 hours and pulverized to obtain pseudoboehmite powder S1. Its physical and chemical properties are listed in Table 1.

[0142] 714.5 g of aluminum sol with a 21 wt% alumina content was added to 1565.5 g of decationized water, stirring was initiated, and 2763 g of kaolin with a 76 wt% solids content was added and dispersed for 60 minutes to obtain a dispersed kaolin slurry. 2049 g of S1 pseudoboehmite with a 61 wt% alumina content was added to 8146 g of decationized water, and under stirring, 210 ml of 36% hydrochloric acid was added. After acidification for 60 minutes, the dispersed kaolin slurry was added, followed by 1500 g (on a dry basis) of finely divided molecular sieves (HSY-12 molecular sieve and ZSP-3 molecular sieve). The weight ratio of HSY-12 molecular sieve to ZSP-3 molecular sieve was 14:1 on a dry basis, both from Sinopec Catalyst Qilu. The molecular sieves were manufactured by Branch. The HSY-12 molecular sieve had a Re2O3 content of 11.6 wt%, a crystallinity of 50.3%, a Na2O content of 0.9 wt%, a Si / Al molar ratio of 2.5, and fine particle sizes d(0.5) = 2.6 and d(0.9) = 6.6. The ZSP-3 molecular sieve had a Fe2O3 content of 1.7 wt%, a P2O5 content of 3.9 wt%, a crystallinity of 78%, a Na2O content of 0.05 wt%, a Si / Al molar ratio of 25, and fine particle sizes d(0.5) = 3.9 and d(0.9) = 7.8. The molecular sieves used in the following examples and comparative examples were also used. The mixture was added and stirred uniformly, then spray-dried, washed with water, and dried to obtain a catalyst. This catalyst is designated SC1. The resulting SC1 catalyst contained, on a dry basis, 30 wt % molecular sieve, 42 wt % kaolin, 25 wt % S1 pseudoboehmite, and 3 wt % aluminum sol.

[0143] Example 2 A sodium metaaluminate solution with a concentration of 45 g / L of Al2O3 was contacted with a 60% volume fraction of carbon dioxide gas (60% CO2 volume fraction, the remainder nitrogen), and the reaction was carried out while controlling the pH to 10.3 at the end of the reaction. The resulting slurry was transferred to an aging vessel and aged at 180°C and 1.0 MPa for 2.5 hours. 1.5% (based on the mass of alumina in the slurry) aqueous ammonia (the concentration of aqueous ammonia calculated as NH3 was 20 wt%) was then added. The temperature was then maintained at 180°C and the pressure at 1.0 MPa. Stirring was then initiated, and the stirring speed was maintained at 450 rpm, allowing the mixture to age continuously for 1 hour. After aging, the resulting slurry was subjected to solid-liquid separation. The solids were washed with deionized water at 95°C for 30 minutes until the pH of the wet filter cake reached 7.3, yielding a pseudoboehmite wet filter cake from which impurities had been removed. The wet filter cake was dried at 90°C for 4 hours and pulverized to obtain pseudo-boehmite powder S2, whose physical and chemical properties are shown in Table 1.

[0144] Referring to the preparation method of Example 1, Y molecular sieve, ZSP-3 molecular sieve, kaolin, water, S2 pseudoboehmite binder, and aluminum sol were prepared into a slurry according to the conventional catalytic cracking catalyst preparation method, and the slurry was spray-dried to prepare a microsphere catalyst. The prepared catalytic cracking catalyst is designated SC2. The obtained SC2 catalyst contained 30 wt. % molecular sieve (Y molecular sieve and ZSP-3 molecular sieve), 42 wt. % kaolin, 25 wt. % S2 pseudoboehmite, and 3 wt. % aluminum sol, calculated on a dry basis.

[0145] Example 3 A sodium metaaluminate solution with a concentration of 8 g / L Al2O3 was contacted with 35% volumetric carbon dioxide gas (35% CO2 volume fraction, remainder nitrogen) and reacted while controlling the pH to 9.2 at the end of the reaction. The resulting slurry was transferred to an aging vessel, and 1.8% (based on the mass of alumina) aqueous ammonia (ammonia concentration calculated as NH3, 20 wt%) was added. The mixture was stirred uniformly and then allowed to stand at 120 °C and 0.2 MPa for 3.5 hours for aging. Stirring was then initiated while maintaining the temperature at 120 °C and the pressure at 0.2 MPa. The mixture was aged for 2.5 hours at a stirring speed of 120 rpm. After aging, the resulting slurry was subjected to solid-liquid separation, and the solids were washed continuously with deionized water at 75 °C for 30 minutes until the pH of the wet filter cake reached 7.2, yielding a pseudoboehmite wet filter cake from which impurities had been removed. The wet filter cake was dried at 75°C for 4 hours and pulverized to obtain pseudo-boehmite powder S3, whose physical and chemical properties are shown in Table 1.

[0146] A catalyst was prepared according to the method of Example 1, using S3 instead of S1, to obtain SC3.

[0147] Example 4 A sodium metaaluminate solution with a concentration of 15 g / L of Al2O3 was contacted with 50% carbon dioxide (50% CO2 volume fraction, remainder nitrogen) and reacted while controlling the pH to 9.9 at the end of the reaction. The resulting slurry was transferred to an aging vessel, and 1.8% urea (based on the mass of alumina in the slurry) was added. The mixture was then aged at 150 °C and 0.48 MPa for 4 hours. Stirring was then initiated while maintaining the temperature at 150 °C and the pressure at 0.48 MPa, and the mixture was aged for 3 hours at a stirring speed of 250 rpm. After aging, the resulting slurry was subjected to solid-liquid separation. The solids were washed continuously with deionized water at 80 °C for 30 minutes until the pH of the wet filter cake reached 7.2, yielding a pseudoboehmite wet filter cake with impurities removed. The wet filter cake was dried at 85 °C for 4 hours and pulverized to obtain pseudoboehmite powder S4. Its physical and chemical properties are shown in Table 1.

[0148] A catalyst was prepared according to the method of Example 1, using S4 instead of S1, to obtain SC4.

[0149] Example 5 A sodium metaaluminate solution with a concentration of 55 g / L of Al2O3 was contacted with 90% carbon dioxide (90% CO2 volume fraction, remainder nitrogen) and reacted while controlling the pH to 10.3 at the end of the reaction. The resulting slurry was transferred to an aging vessel, and 0.7% (based on the mass of alumina) aqueous ammonia (the concentration of aqueous ammonia was 20 wt. % calculated as NH3) was added. The mixture was then aged at 160 °C and 0.62 MPa for 6 hours. Stirring was then initiated while maintaining the temperature at 160 °C and the pressure at 0.62 MPa, and the mixture was aged for 4.5 hours at a stirring speed of 350 rpm. After aging, the resulting slurry was subjected to solid-liquid separation, and the solids were washed continuously with deionized water at 90 °C for 30 minutes until the pH of the wet filter cake reached 7.2, yielding a pseudoboehmite wet filter cake from which impurities had been removed. The wet filter cake was dried at 95°C for 4 hours and pulverized to obtain pseudo-boehmite powder S5, whose physical and chemical properties are shown in Table 1.

[0150]

[0151] A catalyst was prepared according to the method of Example 1, using S5 instead of S1, to obtain SC5.

[0152] (Comparative Example 1) A sodium metaaluminate solution with a concentration of 20 g / L Al2O3 was reacted with 40% carbon dioxide by volume to form a gel while controlling the pH at the end of the reaction to 9.5. The resulting slurry was transferred to an aging vessel and aged at 90°C for 3 hours. After aging, the resulting slurry was subjected to solid-liquid separation, and the solids were washed continuously for 30 minutes with deionized water at 78°C to obtain a filter cake as a product with impurities removed. This was then dried at 90°C for 3 hours and pulverized to obtain pseudoboehmite powder D1. Its physical and chemical properties are shown in Table 1.

[0153] A molecular sieve (the same molecular sieve as used in Example 1), kaolin, water, D1 pseudoboehmite as a binder, and aluminum sol were mixed together to form a slurry according to a conventional catalytic cracking catalyst preparation method, and the slurry was spray-dried to prepare a microsphere catalyst. The prepared catalytic cracking catalyst is designated DC1 (see the preparation method in Example 1). The obtained DC1 catalyst contained, calculated on a dry basis, 30 wt. % molecular sieve, 42 wt. % kaolin, 25 wt. % D1 pseudoboehmite, and 3 wt. % aluminum sol.

[0154] (Comparative Example 2) A sodium metaaluminate solution with a concentration of 20 g / L Al2O3 was reacted with 40% carbon dioxide by volume to form a gel while controlling the pH at the end of the reaction to 9.5. The resulting slurry was transferred to an aging vessel and aged for 3.5 hours at 135°C and 0.35 MPa. After aging, the resulting slurry was subjected to solid-liquid separation, and the solids were washed continuously for 30 minutes with deionized water at 80°C to obtain a pseudo-boehmite wet filter cake from which impurities had been removed. The wet filter cake was dried at 80°C for 3 hours and pulverized to obtain pseudo-boehmite powder D2. Its physical and chemical properties are listed in Table 1.

[0155] A molecular sieve, kaolin, water, D2 pseudoboehmite binder, and aluminum sol were slurried according to a conventional catalytic cracking catalyst preparation method, and the resulting slurry was spray-dried to prepare a microsphere catalyst. The prepared catalytic cracking catalyst is designated DC2 (see the preparation method in Example 1). The obtained DC2 catalyst contained, calculated on a dry basis, 30 wt% molecular sieve, 42 wt% kaolin, 25 wt% D2 pseudoboehmite, and 3 wt% aluminum sol.

[0156] (Comparative Example 3) A high-purity sodium metaaluminate solution containing 45 g / L of Al2O3 was used as the raw material, and a CO2 fraction of 40% was introduced to carry out the gelation reaction. The flow rate was 3.0 m / h. 3The reaction was controlled to: / h, reaction time 40 minutes, Al2O3 residue 5 g / L, and end temperature 35°C. After the reaction, the slurry was separated and washed. The filter cake was washed with highly purified water at 85°C until the pH of the filter cake reached 7.0. The filter cake prepared as described above was added to highly purified water and stirred, followed by the addition of 8 g / L of urea. After stirring for 50 minutes, the slurry was transferred to an autoclave, where the temperature was controlled at 150°C and the pressure at 0.6 MPa and the mixture was aged for 3 hours. After aging, the mixture was washed continuously with deionized water at 85°C for 30 minutes, filtered, and dried at 90°C. The final product, pseudoboehmite D3, was obtained by grinding. Its physical and chemical properties are listed in Table 1.

[0157] Molecular sieve, kaolin, water, D3 pseudoboehmite binder, and aluminum sol were slurried according to a conventional catalytic cracking catalyst preparation method and spray-dried to prepare a microsphere catalyst. The prepared catalytic cracking catalyst is designated DC3 (see the preparation method in Example 1). The obtained DC3 catalyst contained 30 wt% molecular sieve, 42 wt% kaolin, 25 wt% D3 pseudoboehmite, and 3 wt% aluminum sol, calculated on a dry basis.

[0158] Comparative Example 4 A sodium metaaluminate solution with a concentration of 45 g / L Al2O3 was contacted with 60% carbon dioxide gas (60% CO2 volume fraction, remainder nitrogen) and reacted while controlling the pH to 10.3 at the end of the reaction. The resulting slurry was transferred to an aging vessel and aged for 3.5 hours at 180 °C and 1.0 MPa with a stirring speed of 450 rpm. After aging, the resulting slurry was subjected to solid-liquid separation, and the solids were washed continuously with deionized water at 95 °C for 30 minutes until the pH of the wet filter cake reached 7.3, yielding a pseudoboehmite wet filter cake with impurities removed. The wet filter cake was dried at 90 °C for 4 hours and pulverized to obtain pseudoboehmite powder D4. Its physical and chemical properties are listed in Table 1.

[0159] Catalyst DC4 was prepared by following the method of Example 1, using D4 instead of S1.

[0160] [Table 1]

[0161] As can be seen from Table 1, the pseudo-boehmite provided in the present invention has abundant surface hydroxyl groups, larger most probable pore diameter, higher crystallinity, larger crystal size, and larger D (130) / D (020) The pseudo-boehmite has good peptization properties, and the larger most probable pore diameter is maintained even in the calcined sample after peptization.

[0162] [Table 2]

[0163] As can be seen from Table 2, the catalytic cracking catalyst prepared from the pseudo-boehmite provided by the present invention has a lower wear index. The catalytic cracking catalyst prepared from the pseudo-boehmite provided by the present invention has a mesopore distribution of 5.1 nm to 7.7 nm in addition to a pore distribution of 3.8 nm. Catalysts prepared from conventional pseudo-boehmite only have a mesopore distribution of 3.8 nm.

[0164] Examples 6 to 10 After aging the SC1 to SC5 catalysts at 800°C for 17 hours with 100% steam, the catalytic cracking performance of the catalysts was evaluated in a small fixed fluidized bed reactor (ACE). The cracked gas and product oil were collected and analyzed by gas chromatography. The catalyst loading was 9 g, the reaction temperature was 500°C, and the weight hourly space velocity was 16 h -1 The properties of the feedstock oil used in the ACE experiment are shown in Table 3, and the evaluation results are shown in Table 4.

[0165] (Comparative Examples 5 to 8) After aging the DC1 to DC4 catalysts at 800°C with 100% steam for 17 hours, the catalytic cracking performance of the DC1 to DC4 catalysts was evaluated in a small fixed fluidized bed reactor (ACE). The properties of the feedstock oil used in the ACE experiment are shown in Table 3, and the evaluation results are shown in Table 4.

[0166] [Table 3]

[0167] [Table 4]

[0168] From the results shown in Tables 2 and 4, it can be seen that the catalytic cracking catalyst provided in the present invention has a larger mesopore distribution, significantly lower coke selectivity, and significantly higher gasoline yield and liquefied gas yield.

Claims

1. Pseudo-boehmite characterized by a most probable pore diameter of more than 4.5 nm and 12 nm or less, for example, 4.8 nm to 11 nm or 5 nm to 10 nm.

2. I of the pseudoboehmite ３０００～３８００ is 6.0 cm －１ ・mg －１ ~8.5cm －１ ・mg －１ , for example 6.2 cm －１ ・mg －１ ~8.3cm －１ ・mg －１ and I ３０００～３８００ is 3000 cm －１ ~3800cm －１ represents the infrared absorption intensity of the surface hydroxyl groups of pseudo-boehmite in the infrared light wavelength range of I ３０００～３８００ is the mass of the sample (unit: mg) relative to 3000 cm －１ ~3800cm －１ The area of ​​the absorption peak of the sample in the range (unit: cm －１ The pseudo-boehmite according to any one of the above claims, characterized in that the ratio is calculated as follows:

3. The crystal size D of the pseudo-boehmite （１３０） and D （０２０） The ratio of （１３０） / D （０２０） = 1.0 to 1.5, for example 1.1 to 1.3, The crystal size D is measured by powder X-ray diffraction (XRD) and is expressed by the Scherrer equation [Equation 1] where K=1.075, λ is the wavelength of the anodic radiation Kα1 spectral line, β is the half-width (in radians) of a specific diffraction peak of pseudo-boehmite, and θ is the Bragg diffraction angle (in degrees) of the diffraction peak. D （１３０） represents the crystallite size of the sample in the direction perpendicular to the (130) crystal plane; [Equation 2] β １３０ is the half-width of the (130) diffraction peak of the sample (corresponding to 2θ=38.3°), D （０２０） represents the crystal size of the sample in the direction perpendicular to the (020) crystal plane; [Equation 3] β ０２０ is the half-width of the (020) diffraction peak (corresponding to 2θ=14.1°) of the sample, pseudoboehmite.

4. The pseudo-boehmite has a crystal size D （１３０） 2. Pseudo-boehmite according to claim 1, characterized in that it has a particle size of 4 nm to 10 nm, for example 5 nm to 8.5 nm.

5. 10. The pseudo-boehmite according to claim 1, characterized in that the pseudo-boehmite has a crystallinity of 85% to 110%, for example 88% to 108%.

6. 10. The pseudo-boehmite according to claim 1, wherein the peptization index of the pseudo-boehmite is 90% to 100%, for example 93% to 99%.

7. The pore volume of the pseudo-boehmite is 0.3 cm ３ / g ~ 0.58 cm ３ / g, e.g., 0.31 cm ３ / g ~ 0.52 cm ３ The pseudo-boehmite according to any one of the preceding claims, characterized in that:

8. A method for preparing pseudo-boehmite, comprising the steps of: (1) Sodium (meta)aluminate solution was dissolved in CO ２ to form a first slurry; (2) Aging the first slurry under certain conditions, and adding a hydroxyl group regulator during the aging process to obtain an aged slurry; the hydroxyl group regulator is ammonia water and / or NH ３ wherein the aging temperature is 100°C or higher and 185°C or lower, for example, 120°C to 180°C or 120°C to 160°C; preferably, the aging under certain conditions is first static aging, and then aging under stirring; (3) filtering, washing, and drying the aged slurry;

9. In step (1), the sodium (meta)aluminate solution is dissolved in CO ２ The pH value at the end of the reaction with the sodium (meta)aluminate solution is 8.5 to 10.5, for example, 9.2 to 10.3, and the Al ２ O ３ The method for preparing pseudo-boehmite according to any one of the preceding claims, characterized in that the concentration is 5 g / L to 60 g / L, for example 8 g / L to 45 g / L.

10. In step (1), the sodium (meta)aluminate solution is dissolved in CO ２ The reaction conditions with: CO ２ CO with a concentration of 20 to 100% by volume, for example 30 to 90% by volume ２ 10. A method for preparing pseudo-boehmite according to claim 1, comprising: introducing a contained gas (the balance being an inert gas such as nitrogen) into a sodium (meta)aluminate solution to cause a reaction; setting the reaction start temperature to 10°C to 35°C; and setting the reaction end temperature to 15°C to 55°C.

11. The method for preparing pseudo-boehmite according to any one of the above claims, wherein in step (2), the aging temperature of the slurry is 100°C or higher and 185°C or lower, for example, 120°C to 180°C or 120°C to 160°C, the aging pressure is 0.2 MPa to 1.0 MPa, and the aging time is 2 hours to 11.5 hours, for example, 3.5 hours to 10.5 hours.

12. The method for preparing pseudo-boehmite according to any one of the above claims, wherein in step (2), the time for the static aging is 1 hour to 8 hours, for example, 1 hour to 6 hours or 2.5 hours to 6 hours, the time for the aging under stirring is 1 hour to 6 hours, for example, 1 hour to 4.5 hours, and the stirring speed for the aging under stirring may be 50 rpm to 450 rpm, for example, 120 rpm to 450 rpm, and preferably the aging is isothermal aging.

13. The method for preparing pseudo-boehmite according to any one of the preceding claims, characterized in that the aging temperature is 120°C to 180°C, and the aging is preferably isothermal aging.

14. The method for preparing pseudo-boehmite according to any one of the preceding claims, characterized in that the hydroxyl group regulator is added before static aging, during static aging, after a certain period of static aging and before aging under stirring, or after the end of static aging and before the start of aging under stirring, or by a combination thereof; the hydroxyl group regulator is added in an amount of 0.5 to 2 wt %, for example 0.7 to 1.8 wt %, calculated as alumina, of the first slurry; and the concentration of ammonia in the ammonia water is preferably 15 to 25 wt %, for example 20 wt %.

15. In step (2), The static aging conditions include: a temperature of 100°C or higher and 185°C or lower, for example, 120°C to 180°C or 120°C to 160°C, a pressure of 0.2MPa to 1.0MPa, and a time of 1 hour to 8 hours, for example, 2.5 hours to 6 hours; The conditions for aging under stirring include: a temperature of 100°C or higher and 185°C or lower, for example, 120°C to 180°C or 120°C to 160°C, a pressure of 0.2MPa to 1.0MPa, a time of 1 hour to 6 hours, for example, 1 hour to 4.5 hours, and a stirring speed of 120rpm to 450rpm; The method for preparing pseudo-boehmite according to any one of the preceding claims, characterized in that the ratio of the time for static aging to the time for aging under stirring is preferably (1-5):1, for example (1.14-3):

1.

16. The method for preparing pseudo-boehmite according to any one of the above claims, characterized in that the washing conditions in the step (3) are that washing is performed with deionized water at 70°C to 100°C until the pH value of the wet filter cake reaches 7 to 7.5; and the drying in the step (3) is performed at a drying temperature of 60°C to 98°C.

17. Use of pseudo-boehmite according to any one of the above claims as a catalyst, carrier, and binder in the petroleum industry; as a carrier coating for automobile exhaust gas treatment catalysts in the automotive industry; as an additive to flame retardants in the fire protection field; as an ink-absorbing coating for high-quality inkjet printing paper in the paper industry; as a gas purification adsorbent, a defluorinator for drinking water, and a decolorizer and deodorizer for industrial wastewater in the environmental protection industry; as an additive to coatings in the construction industry; and as a reinforcing agent in ceramic composites.

18. The method includes the steps of forming an acidic slurry (e.g., the pH value of the acidic slurry is preferably 1.5 to 2.6) from the pseudo-boehmite according to any one of the preceding claims, a molecular sieve, a binder, a clay and water, and spray-drying the slurry; The catalytic cracking catalyst has a most probable pore size of 3.5 nm to 4 nm and 5.1 nm to 10 nm.

19. slurriing the pseudo-boehmite according to any one of the preceding claims with water to form a pseudo-boehmite slurry having a solid content preferably between 5% and 25% by weight, and adding hydrochloric acid, which may have a concentration between 10% and 37% by weight, so that the mass ratio of HCl to pseudo-boehmite, calculated as alumina, is preferably between 0.037 and 0.104; A method for preparing a catalytic cracking catalyst according to any one of the preceding claims, characterized in that it comprises the steps of mixing the pseudo-boehmite slurry with molecular sieves, binders, clay and water to obtain a colloidal slurry having a solid content preferably of 20-40 wt%, spray drying, and optionally washing and drying.

20. 1. A catalytic cracking catalyst comprising, based on 100% by weight of the catalyst, 10% to 50% by weight on a dry basis of a molecular sieve, 10% to 40% by weight on an alumina basis of the pseudo-boehmite according to any one of the preceding claims, 3% to 20% by weight on an oxide basis of a binder, and 10% to 80% by weight on a dry basis of clay, Preferably, the catalytic cracking catalyst has a most probable pore size of 3.5 nm to 4 nm and 5.1 nm to 10 nm; and / or The catalytic cracking catalyst, wherein the molecular sieve is, for example, one or more of a Y-type molecular sieve, a molecular sieve having an MFI structure, a non-zeolitic molecular sieve, and a molecular sieve having a BEA structure.

21. 1. A catalytic cracking catalyst comprising, based on 100 wt. % of the catalyst, 10 wt. % to 50 wt. % of a Y-type molecular sieve on a dry basis, 0 wt. % to 40 wt. % of other molecular sieves on a dry basis, 10 wt. % to 40 wt. % of the pseudo-boehmite according to any one of the preceding claims on an alumina basis, 3 wt. % to 20 wt. % of a binder on an oxide basis, and 10 wt. % to 80 wt. % of a clay on a dry basis, Preferably, the other molecular sieve is one or more of a zeolite having an MFI structure, a beta zeolite, and a non-zeolitic molecular sieve, more preferably, the other molecular sieve is one or more of HZSM-5, ZRP, and ZSP; and / or Preferably, the Y-type molecular sieve is one or more of REY, REHY, DASY, SOY, PSRY, HSY and HRY.

22. A catalytic cracking process comprising the step of contacting and reacting heavy oil with a catalytic cracking catalyst under FCC conditions, The catalytic cracking catalyst is a catalytic cracking catalyst according to any one of the preceding claims, or a catalytic cracking catalyst obtained by the method for preparing a catalytic cracking catalyst according to any one of the preceding claims, For example, the FCC conditions include a reaction temperature of 480° C. to 530° C., a reaction time of 1 second to 10 seconds, and a catalyst-to-oil ratio of 3 to 20:1 by weight.

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