CN-121990596-A - Submicron mesoporous alumina ball and supergravity preparation method thereof

CN121990596ACN 121990596 ACN121990596 ACN 121990596ACN-121990596-A

Abstract

The invention belongs to the technical field of mesoporous functional materials, and particularly discloses a submicron mesoporous alumina ball and a supergravity preparation method thereof, wherein the preparation method comprises the following steps of S1, continuously preparing a suspension of ultra-small aluminum hydroxide nano particles; step S2, continuously preparing submicron aluminum hydroxide balls, and step S3, preparing submicron mesoporous aluminum oxide balls. According to the submicron mesoporous alumina ball and the supergravity preparation method thereof, through the innovative process design, the method can realize the accurate preparation of the alumina ball with the high Kong Rongjie holes under the conditions of no template agent and no auxiliary agent, and simultaneously effectively solve the problems of difficult mass production, poor product uniformity and high cost of the traditional process, and can provide a functional material with excellent performance for the fields of high-end catalyst carriers, high-capacity adsorbents, high-temperature heat insulation ceramics and the like.

Inventors

ZENG XIAOFEI
LI CAI
CHEN JIANFENG
MAO WEI
WANG JIEXIN
WANG DAN

Assignees

北京化工大学
衢州化工新材料创新研究院

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (10)

1. The super-gravity preparation method of the submicron mesoporous alumina ball is characterized by comprising the following steps of: S1, continuously preparing ultra-small aluminum hydroxide nanoparticle suspension; Wherein, the D90 of the ultra-small aluminum hydroxide nano particles is less than 10nm; Step S11, adding organic aluminum salt or inorganic aluminum salt into a solvent, stirring and dissolving until the solution is clear and transparent, and obtaining an aluminum source solution which is marked as feed liquid A; Step S12, adding organic base or inorganic base into the solvent which is the same as that in the step S11, stirring and dissolving until the solution is clear and transparent, and obtaining an alkaline precipitant solution which is marked as feed liquid B; S13, simultaneously injecting the feed liquid A and the feed liquid B into the super-gravity rotating packed bed reactor through a feed inlet, mixing the feed liquid A and the feed liquid B in the super-gravity rotating packed bed reactor for reaction, and directly and continuously discharging from an outlet to obtain ultra-small aluminum hydroxide nanoparticle suspension; S2, continuously preparing submicron aluminum hydroxide balls; and S3, preparing submicron mesoporous alumina balls.
2. The method for preparing submicron mesoporous alumina spheres according to claim 1, wherein in the step S11, the concentration of aluminum ions in the feed liquid A is 0.1-2.0mol/L, and the organic aluminum salt or the inorganic aluminum salt is one or more of aluminum isopropoxide, aluminum sec-butoxide, aluminum tert-butoxide, aluminum chloride, aluminum nitrate and aluminum sulfate; In the step S12, the concentration of the feed liquid B is 0.1-6.0mol/L, and the organic alkali or inorganic alkali is one or more of ethanolamine, diethanolamine, triethanolamine, urea, ammonia water, sodium hydroxide, potassium hydroxide and ammonium bicarbonate; In step S11 and step S12, the solvent is one or more of water, methanol, ethanol, ethylene glycol, n-propanol, isopropanol, glycerol, n-butanol, and isobutanol.
3. The method for preparing submicron mesoporous alumina spheres according to claim 1, wherein in step S13, the feeding flow rate ratio of feed liquid A to feed liquid B is 1:3-3:1, and the volume flow ratio of feed liquid A to feed liquid B fed into the super-gravity rotary packed bed reactor is 0.5-2.
4. The method for preparing submicron mesoporous alumina spheres according to claim 1, wherein in step S13, the rotor speed of the super-gravity rotating packed bed reactor is 100-2500rpm, and the reaction temperature is 10-60 ℃.
5. The method for preparing submicron mesoporous alumina spheres according to claim 1, wherein step S2 comprises continuously introducing the suspension of the submicron aluminum hydroxide nanoparticles into a spray drying tower for atomization and drying to obtain submicron aluminum hydroxide spheres; Wherein the atomization pressure of the spray drying tower is 0.15-1.35MPa, the air inlet temperature of the spray drying tower is 80-180 ℃, and the air outlet temperature of the spray drying tower is 40-100 ℃.
6. The method for preparing submicron mesoporous alumina spheres according to claim 1, wherein the step S3 is specifically that submicron aluminum hydroxide spheres are subjected to gradient calcination treatment, and the submicron mesoporous alumina spheres are obtained.
7. The method for preparing submicron mesoporous alumina spheres according to claim 6, wherein the gradient calcination treatment is specifically that the temperature rising rate of gradient calcination is 2-10 ℃ per minute, the gradient calcination temperature is 100-650 ℃, and the heat preservation time of gradient calcination is 1-5h.
8. The submicron mesoporous alumina spheres prepared by the hypergravity preparation method according to any one of claims 1 to 7, wherein the morphology and the particle size of the submicron mesoporous alumina spheres are specifically regular spheres, the sphericity is more than or equal to 0.95, the particle size is 0.2 to 5 μm, and the average particle size is less than or equal to 1 μm; the mesoporous structure of the submicron mesoporous alumina sphere is specifically that the average pore diameter of mesopores is more than or equal to 10nm, the pore volume is more than or equal to 0.8cm 3 /g, and the specific surface area is 150-300m 2 /g.
9. The submicron mesoporous alumina sphere according to claim 8, wherein the submicron mesoporous alumina sphere is applied to a catalyst carrier, an adsorption separation material, a lithium battery functional coating and high-temperature heat insulation ceramics.
10. The submicron mesoporous alumina ball according to claim 9, wherein the catalyst carrier is a heavy oil hydrogenation catalyst carrier or a catalytic cracking catalyst carrier, the adsorption separation material is VOCs deep adsorption material or heavy metal wastewater treatment material, the lithium-ion functional coating is a diaphragm high-temperature resistant coating or an electrode dispersion medium coating, and the high-temperature heat-insulating ceramic is a high-temperature industrial kiln heat-insulating lining ceramic or an aerospace heat-protecting heat-insulating ceramic.

Description

Submicron mesoporous alumina ball and supergravity preparation method thereof Technical Field The invention belongs to the technical field of mesoporous functional materials, and particularly relates to a submicron mesoporous alumina ball and a supergravity preparation method thereof. Background Mesoporous materials have a unique porous structure that allows them to have low density, large specific surface area, high loading capacity, as compared to conventional materials. The mesoporous alumina balls are used as important functional materials, the submicron spherical morphology of the mesoporous alumina balls can ensure the hydrodynamic performance, and the regular mesoporous structure can provide channels for active component loading and substance transmission, and has irreplaceable functions in the fields of chemical industry, environmental protection, energy sources, high-temperature heat insulation materials and the like. The pore volume is a core index for determining the loading capacity and the mass transfer efficiency of materials, the high Kong Rongjie pore alumina balls are urgent in the scenes of high-end catalyst carriers, high-capacity adsorbents, high-performance high-temperature heat insulation ceramic matrixes and the like, but the preparation technology of the existing submicron mesoporous alumina balls still has a plurality of technical bottlenecks, and the requirements of high pore volume, uniformity, scale and environmental protection are difficult to be considered, and the specific defects are as follows: (1) The preparation of the high pore volume is difficult, the uniformity is poor, the traditional hard template method (such as a silica microsphere template) and the soft template method (such as Cetyl Trimethyl Ammonium Bromide (CTAB)) need to rely on template agents to construct mesoporous, but the template agents are unevenly filled, residues are difficult to remove and the like, so that the pore volume of the product is generally less than or equal to 0.35cm 3/g, the template is not needed in the template-free method, nano particles are unordered, the mesoporous structure is loose, pore channels are easy to collapse after high-temperature calcination, and the cooperation of high pore volume and mesoporous uniformity cannot be realized. (2) The process is complex, the environmental protection cost is high, the purchase cost of the template agent in the template method usually accounts for 30% -40% of the total cost of the raw materials, the silicon-containing wastewater and organic waste gas are generated in the template agent removing process (alkaline washing and high-temperature roasting), the environmental protection treatment cost is high, and the traditional spray drying forming process needs to add additives such as dispersing agents, binders and the like, so that the process cost is increased, mesoporous blockage is easily caused, the product purity is reduced, and the use performance of the material is seriously affected. (3) The aluminum hydroxide nanometer particles prepared by the traditional intermittent stirring method have poor batch stability, have wide particle size distribution, uneven particle size distribution, large sphericity and wide mesoporous pore size distribution of submicron spheres after spray agglomeration, are easy to degrade after the amplification of a small test process, are difficult to realize continuous mass production, and cannot meet the severe requirements of industrial application on batch stability. (4) The product has limited suitability, and the existing product is difficult to be matched in high-end scenes such as heavy oil hydrogenation, high-temperature flue gas adsorption and the like due to low pore volume, large mass transfer resistance and insufficient thermal stability, so that the application expansion of the mesoporous alumina balls is limited. In addition, alumina porous materials of other forms such as alumina flakes and alumina aerogels exist in the prior art. The alumina aerogel is a three-dimensional porous network structure, and although the pore volume of a part of the product can reach more than 1.6cm 3/g, the alumina aerogel is extremely low in mechanical strength and easy to fracture, cannot be independently used as a granular carrier, is mainly applied to the field of heat insulation materials, and has the advantages of easy collapse of the pore structure at high temperature and low thermal stability. Moreover, the pore volume of the existing spherical mesoporous alumina product is generally less than or equal to 0.35cm 3/g, and even if the pore volume of a few non-spherical alumina materials (such as aerogel) is higher, the technical requirement of 'high pore volume + adapting to industrial morphology' is not met for a long time because the morphology limitation can not adapt to industrial scenes such as catalyst carriers and the like. Therefore, the field needs to develop a submicron mesoporous alumina ball and a s