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CN-121974381-A - Large-pore-volume high-strength activated alumina and preparation method thereof

CN121974381ACN 121974381 ACN121974381 ACN 121974381ACN-121974381-A

Abstract

The application relates to the technical field of catalyst carriers, and particularly discloses a macroporous high-strength active alumina and a preparation method thereof. The preparation method of the macroporous high-strength activated alumina comprises the following steps of adding organosilane into pseudo-boehmite slurry with the solid content of 10-25%, reacting for 1-4 hours under the condition of 50-80℃, pH-9 to obtain modified slurry, press-filtering and drying the modified slurry to obtain dry glue, mixing the dry glue with sesbania powder, nitric acid, polyethylene glycol 400 and water, extruding the dry glue into strips, drying for 4-8 hours at the temperature of 100-120 ℃ to obtain a molded product, heating the molded product to 500-650 ℃, preserving the heat for 2-5 hours, and naturally cooling to obtain the high-strength macroporous activated alumina carrier. The active alumina prepared by the application has the dual characteristics of large pore volume and high strength.

Inventors

  • WANG KUN
  • GAO HONGYAN
  • FU YANLI
  • LIU ZHIYUAN
  • WU LEI

Assignees

  • 临朐恒辉新材料有限公司

Dates

Publication Date
20260505
Application Date
20260409

Claims (10)

  1. 1. The preparation method of the macroporous high-strength activated alumina is characterized by comprising the following steps of: S1, adding 1-8 parts by weight of organosilane into 100 parts by weight of pseudo-boehmite slurry with the solid content of 10-25%, and reacting for 1-4 hours under the condition of 50-80℃, pH-9 to obtain modified slurry; S2, press-filtering and drying the modified slurry to obtain dry adhesive, mixing 100 parts by weight of dry adhesive with 3.2-3.8 parts by weight of sesbania powder, 2.1-2.4 parts by weight of nitric acid, 0.5-1 part by weight of polyethylene glycol 400 and 41-44 parts by weight of water, extruding the mixture into strips, and drying the strips at 100-120 ℃ for 4-8 hours to obtain a molded product; And S3, heating the molded product to 500-650 ℃, preserving heat for 2-5 hours, and naturally cooling to obtain the macroporous high-strength activated alumina.
  2. 2. The method for preparing the macroporous high-strength activated alumina according to claim 1, wherein in S1, the organosilane is one or more of aminosilane, epoxysilane and vinylsilane.
  3. 3. The method for producing a large pore volume high strength activated alumina according to claim 2, wherein the organosilane is a mixture of gamma-aminopropyl triethoxysilane and vinyltriethoxysilane in a mass ratio of (2-3): 1.
  4. 4. The preparation method of the macroporous high-strength activated alumina according to claim 1, wherein S1, adding 1-6 parts by weight of organosilane into 100 parts by weight of pseudo-boehmite slurry with the solid content of 10-25%, stirring and reacting for 1h under the condition of 50-60℃, pH-8, heating to 60-70 ℃, adding 0.5-2.5 parts by weight of organophosphorus modifier, and stirring and reacting for 0.5-1.5h to obtain modified slurry; The organic phosphorus modifier is one or two of amino trimethylene phosphoric acid and hydroxy ethylidene diphosphonic acid.
  5. 5. The method for preparing the macroporous high-strength activated alumina according to claim 4, wherein S1, adding 1-6 parts by weight of organosilane into 100 parts by weight of pseudo-boehmite slurry with the solid content of 10-25%, stirring and reacting for 1h under the condition of 50-60℃, pH-8, heating to 60-70 ℃, adding 0.5-2.5 parts by weight of organophosphorus modifier, stirring and reacting for 0.5-1.5h, maintaining 60-70 ℃, adding 0.3-2 parts by weight of branched organoboron modifier, adjusting pH7.5-9.0, and continuing to react for 1-2h to obtain modified slurry; the organic phosphorus modifier is a mixture of amino trimethylene phosphonic acid and hydroxyethylidene diphosphonic acid with the mass ratio of (1.5-2.5): 1; The branched-chain organic boron modifier is one or two of triethanolamine borate and polyethylene glycol borate.
  6. 6. The preparation method of the macroporous high-strength activated alumina according to claim 5, wherein S1, adding 1-6 parts by weight of organosilane into 100 parts by weight of pseudo-boehmite slurry with the solid content of 10-25%, stirring and reacting for 1h under the condition of 50-60℃, pH-8, heating to 60-70 ℃, adding 0.5-2.5 parts by weight of organophosphorus modifier, stirring and reacting for 0.5-1.5h, maintaining 60-70 ℃, adding 0.3-2 parts by weight of branched organoboron modifier, adjusting pH value to 7.5-9.0, continuing to react for 1-2h, heating to 70-75 ℃, adding 0.1-0.5 parts by weight of synergistic auxiliary, adjusting pH value to 8.8-9.2, and reacting for 0.2-0.3h to obtain modified slurry; the organic phosphorus modifier is a mixture of amino trimethylene phosphonic acid and hydroxyethylidene diphosphonic acid with the mass ratio of (1.5-2.5): 1; The branched organoboron modifier is a mixture of triethanolamine borate and polyethylene glycol borate with the mass ratio of (1-1.2) 1; The synergistic agent is a mixture of nano cellulose and rare earth oxide with the mass ratio of (3-5) to 1.
  7. 7. The method for producing a large pore volume high strength activated alumina according to claim 6, wherein the rare earth oxide is a mixture of cerium oxide and lanthanum oxide in a mass ratio of (1-3): 1.
  8. 8. The preparation method of the macroporous high-strength activated alumina according to claim 1, wherein in S1, the preparation method of the pseudo-boehmite slurry comprises the steps of carrying out carbon-separation reaction by adopting sodium metaaluminate solution and carbon dioxide, or carrying out neutralization reaction by adopting aluminum sulfate solution and sodium metaaluminate solution to generate pseudo-boehmite precipitate, and aging, filtering and washing to obtain the pseudo-boehmite slurry with the solid content of 10-25%.
  9. 9. The method for preparing the macroporous high-strength activated alumina according to claim 1, wherein S3 is characterized in that the molded product is firstly heated to 300-350 ℃ at a rate of 1.5-2.5 ℃ per minute, is kept for 1.0-1.5 hours, is then heated to 550-650 ℃ at a rate of 2-3 ℃ per minute, is kept for 3.5-4.5 hours, and is naturally cooled to obtain the macroporous ultrahigh-strength activated alumina.
  10. 10. A macroporous high-strength activated alumina, characterized in that it is prepared by the method of any one of claims 1 to 9.

Description

Large-pore-volume high-strength activated alumina and preparation method thereof Technical Field The application relates to the technical field of catalyst carriers, in particular to a macroporous high-strength activated alumina and a preparation method thereof. Background Activated alumina (gamma-Al 2O3) is used as a typical porous inorganic nonmetallic material, and takes an irreplaceable position in a plurality of core industrial fields such as petrochemical industry, environmental protection, metallurgical materials, water treatment and the like by virtue of excellent adsorption performance, good chemical stability, controllable surface acidity and high thermal stability. The catalyst carrier is a key catalyst carrier for catalytic cracking, hydrofining, isomerization and other reactions, the pore structure characteristics of the catalyst carrier directly influence the diffusion efficiency of reactants and products and the dispersibility of active components, sulfide and nitrogen oxides in the tail gas of the booster industry and the purification of heavy metal ions and fluoride ions in wastewater are removed in the field of environmental protection, the catalyst carrier is used as a core adsorbent of a pressure swing adsorption technology in the field of gas treatment, is applied to dehydration drying and gas separation processes of natural gas, compressed air and the like, and simultaneously is used as a high-performance filler and carrier material in the high-end fields of electronic materials, biological medicines and the like to provide technical support. The pore canal, pore volume and specific surface area of the activated alumina directly determine the adsorption, catalysis and other performances of the activated alumina, and the strength and the wear rate influence the service life of the activated alumina. The higher the quality of alumina, the higher the performance requirements for its pore channels, pore volume, specific surface area, strength, attrition rate, etc. The publication No. CN105381795A discloses a preparation method of an active alumina material, which comprises the following steps of mixing a pore-forming agent, a nitrate solution and pseudo-boehmite, emulsifying at a high speed for 10-30min, adding a nitric acid solution to adjust the pH value to 2.0-4.5, preparing an active alumina material precursor, drying the active alumina material precursor at 80-120 ℃ for 6-12h, and roasting at 600-1000 ℃ for 3-5h, thus preparing the active alumina material, wherein the pore-forming agent is one or more of starch, long-chain fatty alcohol polyoxyethylene ether, long-chain alkyl polyoxyethylene ether and carboxymethyl cellulose. According to the application, pseudo-boehmite is used as a raw material, the prepared active alumina has the characteristics of high specific surface area, high-temperature aging resistance, good catalytic activity and the like, however, a large amount of gas is quickly released when starch is roasted, irregular penetration is easily formed, internal stress cracks are easily initiated, carbon impurities remain in surfactant pore formers such as long-chain fatty alcohol polyoxyethylene ether and the like, sintering of gamma-Al 2O3 crystals and inter-particle combination are prevented, and the strength of the active alumina is reduced. Disclosure of Invention In order to improve the strength of the activated alumina, the application provides a macroporous high-strength activated alumina and a preparation method thereof. In a first aspect, the application provides a preparation method of macroporous high-strength activated alumina, which adopts the following technical scheme, The preparation method of the macroporous high-strength activated alumina comprises the following steps: S1, adding 1-8 parts by weight of organosilane into 100 parts by weight of pseudo-boehmite slurry with the solid content of 10-25%, and reacting for 1-4 hours under the condition of 50-80℃, pH-9 to obtain modified slurry; S2, press-filtering and drying the modified slurry to obtain dry adhesive, mixing 100 parts by weight of dry adhesive with 3.2-3.8 parts by weight of sesbania powder, 2.1-2.4 parts by weight of nitric acid, 0.5-1 part by weight of polyethylene glycol 400 and 41-44 parts by weight of water, extruding the mixture into strips, and drying the strips at 100-120 ℃ for 4-8 hours to obtain a molded product; And S3, heating the molded product to 500-650 ℃, preserving heat for 2-5 hours, and naturally cooling to obtain the macroporous high-strength activated alumina. By adopting the technical scheme, the application utilizes the reaction of organosilane and hydroxyl on the surface of pseudo-boehmite to form stable Si-O-Al covalent bond, strengthens the bonding effect among pseudo-boehmite particles, simultaneously does not introduce carbon residue in the organosilane modification process, does not generate irregular pore canal defects due to quick gas release, effectively solves the