Alumina pellets, method of making and catalytic reforming catalyst

Abstract

The present application relates to a kind of alumina small ball, preparation method and catalytic reforming catalyst, the pore volume of the pore with the pore diameter of 90-99% in total pore volume in the alumina small ball;The proportion of the pore volume of the pore with the pore diameter greater than in total pore volume in the alumina small ball is less than 1%, the proportion of the pore volume of the pore with the pore diameter less than in total pore volume is less than 1%;Alumina small ball contains group IVA metal.The ordered distribution of mesopore in the alumina small ball prepared by the present application, the proportion of micropore is low, the proportion of mesopore is high and concentrated, and the alumina small ball has high specific surface area, large pore volume and high crushing strength;When catalytic reforming catalyst using the alumina small ball of the present application as carrier is used for catalytic reforming reaction, activity and selectivity are high, effectively improve liquid yield, while maintaining higher liquid product aromatic content, strong carbon deposition resistance.

Description

Technical Field

[0001] This invention relates to the field of alumina support technology, specifically to an alumina microsphere, its preparation method, and a catalytic reforming catalyst. Background Technology

[0002] With the increasing weighting of crude oil, the continuous improvement of product quality requirements, and the ongoing refinement of processes, the demands on catalyst performance are rising, which also places new requirements on its support. Typically, a support must provide excellent physical and chemical properties. Its pore structure has a significant impact on the catalyst's activity, selectivity, and lifetime. An effective macropore distribution provides ample contact space between reactants and the catalyst's active sites, facilitating the rapid escape of reaction products and increasing the reaction rate. Simultaneously, the accumulation of residual carbon can extend the catalyst's lifetime to some extent.

[0003] Alumina is widely used as a support, adsorbent, and hydrogenation catalyst in petrochemicals due to its excellent properties such as high specific surface area, narrow particle size distribution, good adsorption properties, thermal stability, and surface acidity. Different industrial production units require catalysts to be manufactured in different shapes and sizes to meet the needs of continuous production. For continuous reforming moving bed catalytic processes producing high-octane gasoline blending components and enriching hydrogen and aromatics, in order to achieve continuous catalyst delivery, meet other industrial design requirements, and reduce catalyst mechanical wear, the alumina support must be made into spherical pellets with a diameter of 1.4–2.0 mm, while maintaining a crushing strength of not less than 39 N / particle.

[0004] The earliest known method for preparing spherical alumina using an aluminum sol hot oil column molding process is patent US2620314. This method involves reacting metallic aluminum with hydrochloric acid solution to prepare an aluminum sol. The sol is then mixed with a hexamethylenetetramine solution and molded in a hot oil column apparatus. After pressure aging in an oil bath, washing with water, drying, calcination, and steam pore-expanding treatment, spherical alumina is obtained. This process requires many steps, each of which takes a long time. The alumina prepared by this process has a diffuse distribution of micropores, with a high proportion of micropores smaller than 8 nanometers, and its hydrothermal stability is relatively low.

[0005] CN104148117B discloses an alumina support and catalyst, with a pore volume of 0.55–0.9 mL / g determined by mercury porosimetry and a specific surface area of ​​180–250 m² determined by nitrogen adsorption. 2The pore volume is 0.40–0.8 mL / g, and the pore distribution of the mesopores, determined by nitrogen adsorption, is as follows: the ratio of pores with a diameter of 4–6 nm to the total mesopore volume is 6.0–11.0%; the ratio of pores with a diameter of 6–20 nm to the total mesopore volume is 88–92%; and the ratio of pores with a diameter greater than 20 nm to the total mesopore volume is 0.2–2.0%. The catalyst prepared from this support exhibits high selectivity and low coking content in naphtha catalytic reforming reactions, and also possesses good strength.

[0006] CN105312091B describes an oil-ammonia column molding process for θ-Al2O3 microsphere supports, wherein the θ-Al2O3 supports have a diameter of 50–130 μm. 2 The catalyst exhibits a specific surface area of ​​0.5–1.0 mL / g and a total pore volume of 0.5–1.0 mL / g. The support contains pores with diameters of 2–10 nm comprising 4–15% of the total pore volume, pores with diameters of 10–20 nm comprising 40–60% of the total pore volume, pores with diameters of 20–50 nm comprising 1.0–5.0% of the total pore volume, and macropores with diameters greater than 50 nm but not greater than 10 μm comprising 20–50% of the total pore volume. The catalyst obtained by loading the active component onto this support demonstrates good reactivity in the dehydrogenation of low-carbon alkanes to olefins.

[0007] CN107837798B describes an alumina microsphere support, its preparation method, and a catalytic reforming catalyst. The alumina microsphere support has a specific surface area of ​​120–250 m². 2 The pore volume is 0.62–0.75 mL / g. Pores with a diameter less than 8 nm account for 2.0–12% of the total pore volume, pores with a diameter of 8–15 nm account for 10–82% of the total pore volume, pores with a diameter of 15–20 nm account for 1.0–50% of the total pore volume, and pores with a diameter greater than 20 nm account for 5.0–40% of the total pore volume. Alumina microspheres prepared by high-temperature aging of oil-ammonia column molding with ammonium carbonate or ammonium bicarbonate solution are used to expand the pores. The resulting alumina microspheres are then used to prepare a catalytic reforming catalyst for catalytic reforming reactions, exhibiting not only high activity and selectivity but also strong resistance to coking.

[0008] CN104511291B discloses a large-pore, high-bulk-density continuous reforming catalyst. The bulk density is increased by introducing aluminum-containing compounds into a low-density alumina support, and the support pore size is further expanded through hydrothermal treatment. The support bulk density is 0.58–0.90 g / mL, the most probable pore size is 8–20 nm, and the catalyst specific surface area is 170–210 m². 2 The catalyst contains platinum, tin or germanium and halogens, with the remainder being alumina support. This catalyst exhibits high activity, high xylene yield, and low coke yield.

[0009] How to produce alumina microspheres with a low proportion of micropores and a high and concentrated proportion of mesopores is a technical problem that urgently needs to be solved. Summary of the Invention

[0010] This invention provides alumina microspheres, a preparation method, and a catalytic reforming catalyst to prepare alumina microspheres with a low proportion of micropores and a high and concentrated proportion of mesopores, as well as a catalyst with excellent catalytic performance.

[0011] In a first aspect, the present invention relates to an alumina microsphere, wherein the diameter of the pore in the alumina microsphere is [missing information]. The pore volume accounts for 90-99% of the total pore volume; the pore diameter of the alumina microspheres is greater than... The pore volume accounts for less than 1% of the total pore volume, and the pore diameter is less than [missing information]. The pore volume of the alumina microspheres accounts for less than 1% of the total pore volume; the alumina microspheres contain Group IVA metals.

[0012] Optionally, the hole diameter is The pore volume accounts for 0-3% of the total pore volume, and the pore diameter is... The pore volume of the pores accounts for 1.0-6.0% of the total pore volume; the pore diameter is less than The pore volume of the pore is 0% of the total pore volume.

[0013] Optionally, the specific surface area of ​​the alumina microspheres is 170-250 m². 2 / g, with a pore volume of 0.70-0.90 mL / g; preferably, the specific surface area of ​​the alumina microspheres is 180-210 m² / g. 2 / g, with a pore volume of 0.75-0.85mL / g.

[0014] Optionally, the crushing strength of the alumina pellets is greater than 50 N / particle.

[0015] Optionally, the diameter of the alumina microspheres is 1.4-2.0 mm.

[0016] Optionally, the Group IVA metal is germanium or tin; the content of the Group IVA metal is 0.1-2.0%, based on the mass of the alumina microspheres.

[0017] Secondly, the present invention relates to a method for preparing the above-mentioned alumina microspheres, comprising: mixing aluminum sol with a Group IVA metal precursor and a template directing agent, and then mixing it with a gelling agent and dripping it into a hot oil column to form a microsphere; wherein the template directing agent is selected from one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, alkyl glycoside, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock polymer and polyoxyethylene-polyoxypropylene ether block copolymer.

[0018] Optionally, the template directing agent is a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock polymer or a poly(ethylene oxide)-poly(propylene oxide) ether block copolymer, and the weight ratio of the template directing agent to the dry alumina in the aluminum sol is (0.5-5):100; preferably, the weight ratio of the template directing agent to the dry alumina in the aluminum sol is (0.8-2.5):100.

[0019] Optionally, the gelling agent is selected from urea and / or hexamethylenetetramine, and the weight ratio of the gelling agent to the dry alumina in the aluminum sol is (50-90):100; preferably, the weight ratio of the gelling agent to the dry alumina in the aluminum sol is (65-80):100.

[0020] Optionally, the solid content of the aluminum sol, calculated as alumina, is 10-30% by mass; preferably, the solid content of the aluminum sol, calculated as alumina, is 15-25% by mass.

[0021] Optionally, the aluminum sol is prepared by reflux reaction of metallic aluminum with hydrochloric acid solution or aluminum chloride solution; when the aluminum sol is prepared by reflux reaction of metallic aluminum with hydrochloric acid solution, the mass ratio of metallic aluminum to hydrochloric acid solution is 1:(3-5), the concentration of hydrochloric acid solution is 15-25% by mass, the temperature of reflux reaction is 60-160℃, and the time is 4-48 hours; preferably, the temperature of reflux reaction is 90-120℃, and the time is 12-30 hours.

[0022] Optionally, the oil phase material in the hot oil column is selected from at least one of kerosene, medical lubricating oil, liquid paraffin oil, and white oil, and the temperature of the oil phase material is 80-110℃ and the thickness is 100-600 cm; preferably, the temperature of the oil phase material is 85-105℃ and the thickness is 150-400 cm; preferably, the oil phase material in the hot oil column is liquid paraffin oil, and the liquid paraffin is C44 with a distillation range of 250-500℃. 16 ~C 20 n-alkanes.

[0023] Optionally, the preparation method further includes collecting the shaped alumina pellets, aging, washing, drying, and calcining.

[0024] Optionally, the aging conditions include: being carried out under sealed conditions at a temperature of 100-180℃ for 4-48 hours; the drying temperature at 80-150℃ for 0.5-24 hours; and the calcination temperature at 400-800℃ for 0.5-24 hours. Preferably, the aging temperature is 110-160℃ for 4-12 hours; the drying temperature is 100-120℃ for 4-12 hours; and the calcination temperature is 500-650℃ for 2-8 hours.

[0025] Optionally, the Group IVA metal precursor is selected from chloride, nitrate or carbonate salts of germanium or tin; the amount of the Group IVA metal precursor is 0.1 to 2.0% by mass of the Group IVA metal, based on the mass of dry alumina in the alumina sol.

[0026] In another aspect, the present invention relates to a catalytic reforming catalyst comprising alumina microspheres and an active component supported on the alumina microspheres, the active component comprising a group VIII metal element and a halogen; the alumina microspheres are the alumina microspheres described above, or are prepared by the preparation method described above.

[0027] Optionally, based on the mass of the alumina microspheres, the mass percentage of the group VIII metal elements is 0.1 to 2.0% by mass, and the mass percentage of the halogens is 0.5 to 4.0% by mass.

[0028] Optionally, the Group VIII metal element is platinum, and the halogen is chlorine.

[0029] Beneficial effects:

[0030] The alumina microspheres prepared by this invention have an ordered distribution of mesopores, a low proportion of micropores, and a high and concentrated proportion of mesopores. The alumina microspheres also have high specific surface area, large pore volume, and high crushing strength. When the catalytic reforming catalyst using the alumina microspheres of this invention as a support is used in the catalytic reforming reaction, it has high activity and selectivity, effectively improves the liquid yield, maintains a high aromatic content in the liquid product, and has strong resistance to carbon deposition. Attached Figure Description

[0031] Figure 1 This is a pore size distribution diagram of the alumina microspheres prepared in Examples 1-4 of this invention (the horizontal axis represents the pore diameter, and the unit is...). The vertical axis represents the differential aperture distribution dV / dD, in cm. 3 ·g -1 ·nm -1 ). Detailed Implementation

[0032] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0033] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0034] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0035] In a first aspect, the present invention provides an alumina microsphere, wherein the diameter of the pore in the alumina microsphere is [missing information]. The pore volume accounts for 90-99% of the total pore volume; the pore diameter of the alumina microspheres is greater than... The pore volume accounts for less than 1% of the total pore volume, and the pore diameter is less than [missing information]. The pore volume of the alumina microspheres accounts for less than 1% of the total pore volume; the alumina microspheres contain Group IVA metals.

[0036] It should be noted that the alumina microspheres of the present invention are alumina microspheres with a concentrated and ordered pore distribution, and the proportion of mesopores is high and concentrated.

[0037] According to one embodiment of the present invention, the diameter of the hole is The pore volume accounts for 0-3% of the total pore volume, and the pore diameter is... The pore volume of the pores accounts for 1.0-6.0% of the total pore volume; the pore diameter is less than The pore volume of the pore is 0% of the total pore volume.

[0038] It should be noted that in the alumina microspheres of this embodiment, The pore volume of the holes accounts for 1-9% of the total pore volume. The volume of the holes accounts for 90-99% of the total hole volume, and the hole diameter is greater than... The pore volume of the microspheres accounts for 0-1% of the total pore volume. In this embodiment, the alumina microspheres are basically free of micropores, and the proportion of mesopores is high and concentrated, exhibiting a well-ordered pore distribution characteristic, making them more suitable as a support for loading active substances to form high-performance catalysts.

[0039] In a preferred embodiment, the specific surface area of ​​the alumina microspheres is 170-250 m². 2The alumina microspheres have a pore volume of 0.70-0.90 mL / g and a crushing strength greater than 50 N / particle; preferably, the specific surface area of ​​the alumina microspheres is 180-210 m² / g. 2 The alumina microspheres produced in this embodiment not only have a high and concentrated proportion of mesopores, but also possess high specific surface area, large pore volume, and high crushing strength, making them more suitable as catalyst supports for preparing catalysts with strong mechanical abrasion resistance and superior catalytic performance.

[0040] According to one embodiment of the present invention, the diameter of the alumina microspheres is 1.4-2.0 mm. Preferably, the diameter of the alumina microspheres is 1.6 mm. Alumina microspheres within the above-mentioned diameter range can achieve better mechanical wear performance when adsorbing active components to prepare catalysts.

[0041] According to one embodiment of the present invention, the Group IVA metal is germanium or tin, preferably tin; the content of the Group IVA metal is 0.1-2.0%, based on the mass of the alumina microspheres.

[0042] It should be noted that the content of Group IVA metals can refer to the content of Group IVA metals such as Sn; the content of Group IVA metals can be 0.1% to 2.0%, or it can be based on the mass of dry alumina in the alumina sol used to prepare the alumina microspheres. This is because, after calcination, the template directing agent and gelling agent have decomposed or volatilized at high temperatures, and the alumina in the alumina sol and the Group IVA metals in the added Group IVA metal precursors are all present in the generated alumina microspheres. The added Group IVA metal precursors are very small compared to the mass of dry alumina in the alumina sol.

[0043] Secondly, the present invention provides a method for preparing the above-mentioned alumina microspheres, comprising: mixing aluminum sol with a Group IVA metal precursor and a template directing agent, and then mixing it with a gelling agent and dripping it into a hot oil column to form a microsphere; wherein the template directing agent is selected from one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, alkyl glycoside, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock polymer and polyoxyethylene-polyoxypropylene ether block copolymer.

[0044] It should be noted that in the preparation method of this invention, aluminum sol is first mixed with a Group IVA metal precursor and a template directing agent for a certain time, for example, 0.5-2 hours, to obtain a first mixture; then, the first mixture is mixed with a gelling agent for a certain time, for example, 0.5-2 hours, to obtain a final mixture. This final mixture is then dropped into a column of hot oil to form a spherical shape. The droplets shrink into spherical shapes due to surface tension, and the spheres form gel spheres during their fall. The alumina spheres prepared by the method of this invention have high crushing strength, concentrated pore distribution, a high and concentrated proportion of mesopores, and a low proportion of micropores.

[0045] It should be noted that in the preparation method of the present invention, aluminum sol, Group IVA metal precursor and template directing agent are first mixed. The template directing agent can coat the particles of alumina and Group IVA metal precursor, so that the particles of alumina and Group IVA metal precursor in aluminum sol form particles coated by the template directing agent. Then, a gelling agent is added and mixed, and the mixture is formed by hot oil column molding. The final alumina microspheres have a high and concentrated proportion of pores.

[0046] In a preferred embodiment, the template directing agent is a poly(ethylene oxide-poly(propylene oxide-poly(ethylene oxide)) triblock polymer (PEO-PPO-PEO) or a poly(ethylene oxide-poly(propylene oxide)) block copolymer, and the weight ratio of the template directing agent to the dry alumina in the aluminum sol is (0.5-5):100; preferably, the weight ratio of the template directing agent to the dry alumina in the aluminum sol is (0.8-2.5):100.

[0047] It should be noted that, in this preferred embodiment, the number average molecular weight of the polyethylene oxide-polypropylene oxide-polyethylene oxide triblock polymer can be 1000-10000, preferably 5800. The number average molecular weight of the polyoxyethylene-polyoxypropylene ether block copolymer can be 2000-15000, preferably 7000. Both polymers can be purchased from reagent companies such as Beijing Innocare Technology Co., Ltd.

[0048] According to one embodiment of the present invention, the gelling agent is selected from urea and / or hexamethylenetetramine, and the weight ratio of the gelling agent to the dry alumina in the aluminum sol is (50-90):100; preferably, the weight ratio of the gelling agent to the dry alumina in the aluminum sol is (65-80):100.

[0049] It should be noted that in the process of preparing alumina microspheres by the oil column method, adding the above-mentioned gelling agent according to the above dosage is beneficial to the better agglomeration or gelation of alumina in the alumina sol into alumina microspheres. This helps the alumina microspheres to form an ordered pore distribution with concentrated mesopores, a low proportion of micropores, and exhibit a large specific surface area, large pore volume, and high crushing strength.

[0050] According to one embodiment of the present invention, the solid content of the aluminum sol, calculated as alumina, is 10-30% by mass; preferably, the solid content of the aluminum sol, calculated as alumina, is 15-25% by mass.

[0051] It should be noted that in the process of preparing alumina microspheres, while controlling the selection and dosage of the template guiding agent and gelling agent, the solid content in the alumina sol and the preparation process of the alumina sol also have a certain influence or effect on the parameters such as pore size distribution, pore volume, specific surface area and crushing strength of the prepared alumina microspheres.

[0052] According to one embodiment of the present invention, the aluminum sol is prepared by reflux reaction of metallic aluminum with hydrochloric acid solution or aluminum chloride solution; when the aluminum sol is prepared by reflux reaction of metallic aluminum with hydrochloric acid solution, the mass ratio of metallic aluminum to hydrochloric acid solution is 1:(3-5), the concentration of hydrochloric acid solution is 15-25% by mass, the temperature of reflux reaction is 60-160°C, and the time is 4-48 hours; preferably, the temperature of reflux reaction is 90-120°C, and the time is 12-30 hours.

[0053] It should be noted that the aluminum can be in the form of aluminum ingots, aluminum sheets or aluminum powder, and the mass ratio of aluminum to chlorine in the aluminum sol can be (1.0-1.4):1.

[0054] According to one embodiment of the present invention, the oil phase material in the hot oil column is selected from at least one of kerosene, medical lubricating oil, liquid paraffin oil, and white oil, and the temperature of the oil phase material is 80-110°C and the thickness is 100-600 cm; preferably, the temperature of the oil phase material is 85-105°C and the thickness is 150-400 cm; preferably, the oil phase material in the hot oil column is liquid paraffin oil, and the liquid paraffin is C44 with a distillation range of 250-500°C. 16 ~C 20 n-alkanes.

[0055] It should be noted that, in the process of forming alumina microspheres from hot oil column, by selecting the oil phase material of the hot oil column and controlling the above conditions, the mixture of aluminum sol, IVA group metal precursor, template guide agent and gelling agent can be better formed into alumina microspheres with concentrated mesopore distribution, and a large specific surface area, pore volume and crushing strength can be obtained.

[0056] According to one embodiment of the present invention, the preparation method further includes collecting the shaped alumina microspheres, aging, washing with water, drying and calcining.

[0057] According to one embodiment of the present invention, the aging conditions include: being carried out under sealed conditions at a temperature of 100-180°C for 4-48 hours, or for 4-24 hours; the drying temperature is 80-150°C for 0.5-24 hours; the calcination temperature is 400-800°C for 0.5-24 hours; preferably, the aging temperature is 110-160°C for 4-12 hours; the drying temperature is 100-120°C for 4-12 hours; and the calcination temperature is 500-650°C for 2-8 hours.

[0058] It should be noted that in the preparation method of the present invention, by controlling the steps after molding as described above, the alumina microspheres with concentrated distribution of mesopores obtained in the end can obtain better crushing strength.

[0059] According to one embodiment of the present invention, the Group IVA metal precursor is selected from chloride, nitrate, or carbonate salts of germanium or tin; the amount of the Group IVA metal precursor, based on the mass of the Group IVA metal and the dry-basis alumina in the alumina sol, is 0.1–2.0%. The preferred Group IVA metal precursor is tin chloride.

[0060] Thirdly, the present invention provides a catalytic reforming catalyst comprising alumina microspheres and an active component supported on the alumina microspheres, wherein the active component comprises a group VIII metal element and a halogen; the alumina microspheres are the alumina microspheres described above, or are prepared by the preparation method described above.

[0061] According to one embodiment of the present invention, based on the mass of the alumina microspheres, the mass percentage of the group VIII metal elements is 0.1 to 2.0% by mass, and the mass percentage of the halogens is 0.5 to 4.0% by mass.

[0062] According to one embodiment of the present invention, the Group VIII metal element is platinum and the halogen is chlorine.

[0063] It should be noted that the catalytic reforming catalyst provided by this invention is suitable for hydrocarbon catalytic reforming, and the catalytic reforming feedstock can be C6-C. 12 For monomeric or mixed hydrocarbons, such as naphtha, the catalytic reforming conditions may include: a temperature of 350-700°C, a pressure of 0.1-2.0 MPa, and a liquid hourly space velocity of 0.5-4.0 h⁻¹. -1 .

[0064] The present invention is further illustrated below by way of examples, but the present invention is not limited thereto.

[0065] In the examples and comparative examples, the crushing strength of alumina pellets was measured using a ZQJ intelligent particle strength testing machine manufactured by Dalian Equipment Diagnostic Instrument Factory, with a force application rate of 5 N / s and a range of 250 N.

[0066] The specific surface area and pore volume of alumina microspheres were determined using a low-temperature nitrogen adsorption method on a Micromeritics ASAP2400 instrument. The specific surface area was calculated using the BET method, and the pore volume was calculated when the relative pressure P / P0 was 0.99, where P is the measurement pressure and P0 is the saturated vapor pressure of N2 at the adsorption temperature. The pore size distribution of the sample was calculated using desorption curves. The diameter of the alumina microspheres was measured using vernier calipers. A certain mass of alumina microspheres was weighed using an electronic balance, and their compacted volume was measured using a graduated cylinder; the quotient of the two measurements yielded the bulk density of the alumina microspheres. The amount of coke deposited on the catalyst was measured using a HORIBA EMIA-820V infrared sulfur and carbon analyzer.

[0067] The liquid yield is the ratio of the mass of liquid product collected per unit reaction time to the mass of feed. The aromatic content of the liquid product is detected by an Agilent gas chromatograph G7890 with a flame ionization detector. The relative content of each component is calculated using the area normalization method. The aromatic yield is the product of the liquid yield and the aromatic content.

[0068] In the following examples, P123 represents a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock polymer with a number-average molecular weight of 5800, and F127 represents a poly(ethylene oxide)-poly(propylene oxide) ether block copolymer with a number-average molecular weight of 7000. Both were purchased from Beijing Innocare Technology Co., Ltd. All other reagents used in the following examples were commercially available.

[0069] Example 1

[0070] (1) Preparation of aluminum sol

[0071] 115g of aluminum sheet was mixed with 450g of 20% hydrochloric acid solution and refluxed at 100℃ for 24h. After cooling and filtration, aluminum sol was obtained with a solid content of 21% by mass based on alumina and an aluminum / chlorine mass ratio of 1.05.

[0072] (2) Hot oil column forming

[0073] The oil phase of the hot oil column is liquid paraffin oil, the oil phase temperature is 100℃, and the oil phase thickness is 200cm. Take 500g of the aluminum sol obtained in step (1), add 0.62g of SnCl2·2H2O and 1.1g of P123, stir and dissolve for 0.5h, then add 10g of urea and 220g of 30% hexamethylenetetramine solution and stir for 0.5h. Then drop it into the hot oil column to form. Take out the hot oil column formed into small balls at the bottom of the device, and then seal them in a high pressure vessel for static aging treatment at 138℃ for 6h, wash with water, dry at 110℃ for 4h, and calcine at 600℃ for 4h to obtain finished alumina small balls. The particle diameter (ball diameter), bulk density, crushing strength, specific surface area, pore volume and pore distribution are shown in Table 1. The pore size distribution curve is shown in Table 2. Figure 1 .

[0074] (3) Preparation of reforming catalyst

[0075] In 17.5 mL of chloroplatinic acid aqueous solution with a platinum concentration of 8.3 mg / mL, 15 mL of hydrochloric acid solution with a concentration of 100 mg / mL and 70 mL of deionized water were added. Then, 50 g of the alumina microspheres prepared in step (2) were added and stirred for 1 h, and then allowed to stand for 12 h. The filtrate was filtered out, and the impregnated alumina microspheres were dried at 120 °C for 10 h. Then, they were air-treated at 520 °C for 6 h under a gas / agent volume ratio of 500. Then, hydrogen reduction was carried out for 6 h to obtain a reduced catalytic reforming catalyst, in which the platinum content based on alumina was 0.29% by mass.

[0076] (4) Catalytic reforming reaction

[0077] Using hydrotreated straight-run naphtha as feedstock, the specific properties of which are shown in Table 2, the prepared catalyst was evaluated for catalytic reforming under the following conditions: temperature 500℃, reaction pressure 0.7 MPa, hydrogen / hydrocarbon volume ratio 1000, and liquid hourly space velocity (LISH) 1.8 h⁻¹. -1 The total reaction time was 120 hours, and the reaction results are shown in Table 3.

[0078] Example 2

[0079] (1) Preparation of aluminum sol

[0080] Take 115g of aluminum sheet and mix it with 420g of 20% hydrochloric acid solution. Reflux the mixture at 110℃ for 24h. After cooling and filtration, aluminum sol is obtained with a solid content of 22.4% by mass based on alumina and an aluminum / chlorine mass ratio of 1.15.

[0081] (2) Hot oil column forming

[0082] Take 500g of the aluminum sol obtained in step (1), add 0.66g of SnCl2·2H2O and 1.5g of P123, stir and dissolve for 0.5h, then add 250g of 30% by mass hexamethylenetetramine solution and stir for 0.5h. Prepare hot oil column shaped spheres according to the method of step (2) in Example 1. Then, perform aging treatment at 138℃ for 6h, water washing, drying at 110℃ for 2h, and calcination at 600℃ for 4h to obtain alumina spheres. The particle diameter, bulk density, crushing strength, specific surface area, pore volume and pore distribution are shown in Table 1. The pore size distribution curve is shown in Table 1. Figure 1 .

[0083] (3) Preparation of reforming catalyst and catalytic reforming reaction

[0084] The alumina microspheres obtained in step (2) were used to prepare a catalytic reforming catalyst according to the method in step (3) of Example 1 and the catalytic reforming reaction performance was evaluated according to the method in step (4) of Example 1. The reaction results are shown in Table 3.

[0085] Example 3

[0086] (1) Preparation of aluminum hydroxide sol

[0087] Take 115g of aluminum sheet and mix it with 400g of 20% hydrochloric acid solution. Reflux at 120℃ for 24h. After cooling and filtration, aluminum sol is obtained with a solid content of 23.6% by mass based on alumina and an aluminum / chlorine mass ratio of 1.25.

[0088] (2) Hot oil column forming

[0089] Take 500g of the aluminum sol obtained in step (1), add 0.70g of SnCl2·2H2O and 2.0g of P123, stir and dissolve for 0.5h, then add 256g of 30% by mass hexamethylenetetramine solution and stir for 0.5h. Prepare hot oil column-formed microspheres according to the method of step (2) in Example 1, and then perform aging treatment at 138℃ for 6h, water washing, drying at 110℃ for 2h, and calcination at 600℃ for 4h to obtain alumina microspheres. The particle diameter, bulk density, crushing strength, specific surface area, pore volume and pore distribution are shown in Table 1, and the pore size distribution curve is shown in Table 2. Figure 1 .

[0090] (3) Preparation of reforming catalyst and catalytic reforming reaction

[0091] The alumina microspheres obtained in step (2) were used to prepare a catalytic reforming catalyst according to the method in step (3) of Example 1 and the catalytic reforming reaction performance was evaluated according to the method in step (4) of Example 1. The reaction results are shown in Table 3.

[0092] Example 4

[0093] Aluminum sol was prepared according to step (1) of Example 1.

[0094] (2) Hot oil column forming

[0095] Take 500g of aluminum sol from step (1), add 0.65g of SnCl2·2H2O and 1.5g of F127, stir and dissolve for 0.5h, then add 15g of urea and 200g of 30% by mass hexamethylenetetramine solution and stir for 0.5h. Prepare hot oil column-formed microspheres according to the method of step (2) in Example 1, and then perform aging treatment at 138℃ for 6h, water washing, drying at 110℃ for 2h, and calcination at 600℃ for 4h to obtain alumina microspheres. The particle diameter, bulk density, crushing strength, specific surface area, pore volume and pore distribution are shown in Table 1, and the pore size distribution curve is shown in Table 2. Figure 1 .

[0096] (3) Preparation of reforming catalyst and catalytic reforming reaction

[0097] The alumina microspheres obtained in step (2) were used to prepare a catalytic reforming catalyst according to the method in step (3) of Example 1 and the catalytic reforming reaction performance was evaluated according to the method in step (4) of Example 1. The reaction results are shown in Table 3.

[0098] Comparative Example 1

[0099] Aluminum sol was prepared according to the method in Example 1, except that template directing agent P123 was not added to the aluminum sol. 115g of aluminum sheet was mixed with 450g of 20% by mass hydrochloric acid solution, and the mixture was refluxed at 100°C for 24h. After filtration, aluminum sol was obtained. Take 500g of the aluminum sol obtained above, add 0.62g of SnCl2·2H2O, stir and dissolve for 0.5h, then add 20g of urea and 220g of 30% by mass hexamethylenetetramine solution and stir for 0.5h. Drop the mixture into a hot oil column with liquid paraffin as the oil phase to form spheres. The oil phase temperature is 100℃ and the oil phase thickness is 200cm. After the spheres are taken out from the bottom of the hot oil column, they are sealed in a kettle for aging treatment. The medium is liquid paraffin, the aging temperature is 138℃, and the aging time is 6h. Then the spheres are taken out, washed with water, dried at 110℃ for 2h, and calcined at 600℃ for 4h to obtain γ-Al2O3 spheres. The particle diameter, bulk density, crushing strength, specific surface area, pore volume and pore distribution are shown in Table 1. The catalytic reforming catalyst was prepared according to the method in step (3) of Example 1 and the catalytic reforming reaction performance was evaluated according to the method in step (4) of Example 1. The reaction results are shown in Table 3.

[0100] Comparative Example 2

[0101] Alumina microspheres were prepared according to the method in Example 1 of CN105502447B.

[0102] Take 65.8g of pseudoboehmite powder prepared by the hydrolysis method of aluminum alkoxy (manufactured by Condea GmbH, Germany, grade SB, specific surface area 250m²). 2 / g, dry basis mass is 50g), 26.0g urea and appropriate amount of deionized water, stir to form a suspension with an alumina content of 21% by mass, stir for 0.5h, add 11.7g of nitric acid solution with a concentration of 24% by mass dropwise, stir at 20℃ for 1h to obtain alumina sol, mix alumina sol with 20g of hexamethylenetetramine solution with a concentration of 20% by mass and stir for 0.5h, drop into a hot oil column with liquid paraffin as the oil phase to form spheres, the oil phase temperature is 100℃ and the oil phase thickness is 200cm, directly take out the spheres at the bottom of the device, wash with water, dry at 110℃ for 2h, calcine at 600℃ for 4h to obtain γ-Al2O3 spheres, the particle diameter, bulk density, crushing strength, specific surface area, pore volume and pore size distribution are shown in Table 1, the catalytic reforming catalyst is prepared according to the method of step (3) in Example 1 and the catalytic reforming reaction performance is evaluated according to the method of step (4) in Example 1, the reaction results are shown in Table 3.

[0103] Table 1

[0104]

[0105]

[0106] The pore distribution values ​​in Table 1, such as those of the alumina microspheres in Example 1. A pore distribution value of 1.07% refers to a pore diameter of... The pore volume accounts for 1.07% of the total pore volume.

[0107] Table 2

[0108]

[0109] Table 3

[0110]

[0111]

[0112] In the description of this application, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0113] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0114] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A method for preparing alumina microspheres, characterized in that, include: Aluminum sol is mixed with IVA group metal precursors and template directing agent, then mixed with gelling agent and dripped into hot oil column to form; The template directing agent is selected from polyethylene oxide-polypropylene oxide-polyethylene oxide triblock polymer or polyoxyethylene-polyoxypropylene ether block copolymer; The gelling agent is selected from urea and / or hexamethylenetetramine; and In these alumina microspheres, the pore volume with a diameter of 100-200 Å accounts for 91.46-99% of the total pore volume; The alumina microspheres contain pores with a diameter greater than 200 Å, whose pore volume accounts for less than 1% of the total pore volume; pores with a diameter of 80-100 Å, whose pore volume accounts for 1.0-6.0% of the total pore volume; pores with a diameter of 60-80 Å, whose pore volume accounts for 0-2.27% of the total pore volume; and pores with a diameter less than 60 Å, whose pore volume accounts for less than 1% of the total pore volume. The alumina microspheres contain Group IVA metals.

2. The preparation method according to claim 1, characterized in that, The pore volume of pores with a diameter less than 60 Å accounts for 0% of the total pore volume.

3. The preparation method according to claim 1 or 2, characterized in that, The specific surface area of ​​the alumina microspheres is 170-250 m². 2 / g, with a pore volume of 0.70-0.90mL / g.

4. The preparation method according to claim 3, characterized in that, The diameter of the alumina microspheres is 1.4-2.0 mm.

5. The preparation method according to claim 3, characterized in that, The IVA metal is germanium or tin; the content of the IVA metal is 0.1~2.0%, based on the mass of the alumina microspheres.

6. The preparation method according to claim 3, characterized in that, The specific surface area of ​​the alumina microspheres is 180-210 m². 2 / g, with a pore volume of 0.75-0.85mL / g.

7. The preparation method according to claim 1, characterized in that, The weight ratio of the template guiding agent to the dry alumina in the aluminate sol is (0.5-5):

100.

8. The preparation method according to claim 1, characterized in that, The weight ratio of the gelling agent to the dry alumina in the aluminum sol is (50-90):

100.

9. The preparation method according to claim 1, characterized in that, The solid content of the alumina sol is 10-30% by mass, calculated as alumina.

10. The preparation method according to claim 9, characterized in that, The aluminum sol is prepared by reflux reaction of metallic aluminum with hydrochloric acid solution or aluminum chloride solution. When the aluminum sol is prepared by reflux reaction of metallic aluminum and hydrochloric acid solution, the mass ratio of metallic aluminum to hydrochloric acid solution is 1:(3-5), the concentration of hydrochloric acid solution is 15-25% by mass, the temperature of reflux reaction is 60-160℃, and the time is 4-48 hours.

11. The preparation method according to claim 10, characterized in that, The oil phase material in the hot oil column is selected from at least one of kerosene, medical lubricating oil and liquid paraffin oil, and the temperature of the oil phase material is 80-110℃ and the thickness is 100-600 cm.

12. The preparation method according to claim 11, characterized in that, The method also includes collecting the shaped alumina pellets, aging, washing, drying, and calcining.

13. The preparation method according to claim 12, characterized in that, The aging conditions include: being carried out under sealed conditions at a temperature of 100-180℃ for 4-48 hours; the drying temperature is 80-150℃ for 0.5-24 hours; and the calcination temperature is 400-800℃ for 0.5-24 hours.

14. The preparation method according to claim 13, characterized in that, The Group IVA metal precursor is selected from chloride, nitrate or carbonate salts of germanium or tin; the amount of the Group IVA metal precursor is 0.1 to 2.0% by mass of the Group IVA metal, based on the mass of dry alumina in the aluminum sol.

15. The preparation method according to claim 7, characterized in that, The weight ratio of the template guiding agent to the dry alumina in the aluminosilicate is (0.8-2.5):

100.

16. The preparation method according to claim 8, characterized in that, The weight ratio of the gelling agent to the dry alumina in the aluminum sol is (65-80):

100.

17. The preparation method according to claim 9, characterized in that, The solid content of the alumina sol is 15-25% by mass, calculated as alumina.

18. The preparation method according to claim 10, characterized in that, The reflux reaction is carried out at a temperature of 90-120°C for 12-30 hours.

19. The preparation method according to claim 11, characterized in that, The oil phase material has a temperature of 85-105℃ and a thickness of 150-400 cm.

20. The preparation method according to claim 11, characterized in that, The oil phase material in the hot oil column is liquid paraffin oil, which is a C400 oil with a distillation range of 250~500℃. 16 ~C 20 n-alkanes.

21. The preparation method according to claim 13, characterized in that, The aging temperature is 110-160℃ and the time is 4-12 hours; the drying temperature is 100-120℃ and the time is 4-12 hours; the calcination temperature is 500-650℃ and the time is 2-8 hours.

22. An alumina microsphere, characterized in that, Prepared by the method according to any one of claims 1 to 21.

23. A catalytic reforming catalyst, characterized in that, The catalytic reforming catalyst comprises alumina spheres and an active component supported on the alumina spheres, wherein the active component comprises group VIII metal elements and halogens; The alumina microspheres are prepared by the preparation method according to any one of claims 1-21.

24. The catalytic reforming catalyst according to claim 23, characterized in that, Based on the mass of the alumina microspheres, the mass percentage of the group VIII metal elements is 0.1 to 2.0% by mass, and the mass percentage of the halogens is 0.5 to 4.0% by mass.

25. The catalytic reforming catalyst according to claim 24, characterized in that, The group VIII metal element is platinum, and the halogen is chlorine.

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