A method for aluminum salt-assisted hydrothermal synthesis of pseudo-boehmite

Abstract

A disclosed aluminium-salt-assisted hydro-thermal synthesis method for pseudo-boehmite comprises the steps: 1) adding a certain amount of aluminium sulfate, urea and a surfactant into proper amount of deionized water, fully dissolving and adding active aluminium oxide in batches, and stirring uniformly to obtain a solid-liquid mixture; 2) performing homogenization and refinement on the obtained solid-liquid mixture, and then transferring into a high-pressure reaction kettle for hydrothermal reaction; and 3) after the reaction is finished, performing solid-liquid separation on the obtained reaction product, fully washing and drying, so as to obtain the pseudo-boehmite powder. The prepared pseudo-boehmite possesses the characteristics of high purity, high pore volume and specific surface area, and especially high pore-volume retention rate during molding, and also the technology is simple in operation, low in cost, free of waste discharge and easy for industrial amplification.

Description

technical field

[0001] The invention belongs to the technical field of inorganic material preparation, and in particular relates to a method for hydrothermally synthesizing pseudo-boehmite with the assistance of aluminum sulfate salts to activated alumina. Background technique

[0002] Pseudoboehmite, also known as monohydrate alumina, pseudo-boehmite, is one of the important categories of chemical alumina. Pseudo-boehmite is mainly used as a raw material for making catalysts, such as a binder or catalyst carrier for cracking, hydrogenation and reforming catalysts in the petrochemical industry; in the nitrogen fertilizer production industry, pseudo-boehmite is used for ammonia production Catalyst carrier; In terms of environmental protection, pseudo-boehmite is widely used in the preparation of catalysts for automobile exhaust purification.

[0003] The production methods of pseudo-boehmite mainly include inorganic aluminum salt precipitation and aluminum alkoxide hydrolysi...

Examples

Embodiment 1

[0021] Add 666g of aluminum sulfate octadecahydrate to 9.6kg of deionized water, then add 240g of urea, and add 24g of cetyltrimethylammonium bromide. After fully dissolving, add 1.9kg of activated alumina in batches, and stir to obtain a solid-liquid mixture. , the obtained slurry was sand-milled to obtain a slurry with an average particle size of 0.4 μm, and then the slurry obtained by sand-milling was transferred to a high-pressure reactor, and hydrothermally reacted at 150 ° C for 24 hours. After the reaction, the obtained slurry was separated from solid and liquid, fully Washing, spray drying to obtain pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

Embodiment 2

[0025] Add 260g of aluminum sulfate octadecahydrate to 10kg of deionized water, then add 80g of urea, and add 80g of polyethylene glycol-2000, after fully dissolving, add 1.2kg of activated alumina in batches, stir evenly to obtain a solid-liquid mixture, and carry out the obtained slurry Sand milling treatment to obtain a slurry with an average particle size of 1.5 μm, and then transfer the slurry obtained by sand milling to a high-pressure reactor, and conduct a hydrothermal reaction at 200 ° C for 8 hours. After the reaction, the obtained slurry is separated from solid and liquid, fully washed, and spray-dried to obtain Pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

Embodiment 3

[0029] Add 34g of aluminum sulfate octadecadecane to 10kg of deionized water, then add 12g of urea, and add 24g of sodium tartrate. After fully dissolving, add 0.5kg of activated alumina in batches, stir to obtain a solid-liquid mixture, and obtain a slurry with an average particle size of 12 μm. Then the obtained slurry was transferred to an autoclave for hydrothermal reaction at 250° C. for 1 hour. After the reaction, the obtained slurry was separated from solid to liquid, fully washed, and spray-dried to obtain pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

technical field

[0001] The invention belongs to the technical field of inorganic material preparation, and in particular relates to a method for hydrothermally synthesizing pseudo-boehmite with the assistance of aluminum sulfate salts to activated alumina. Background technique

[0002] Pseudoboehmite, also known as monohydrate alumina, pseudo-boehmite, is one of the important categories of chemical alumina. Pseudo-boehmite is mainly used as a raw material for making catalysts, such as a binder or catalyst carrier for cracking, hydrogenation and reforming catalysts in the petrochemical industry; in the nitrogen fertilizer production industry, pseudo-boehmite is used for ammonia production Catalyst carrier; In terms of environmental protection, pseudo-boehmite is widely used in the preparation of catalysts for automobile exhaust purification.

[0003] The production methods of pseudo-boehmite mainly include inorganic aluminum salt precipitation and aluminum alkoxide hydrolysi...

Examples

Embodiment 1

[0021] Add 666g of aluminum sulfate octadecahydrate to 9.6kg of deionized water, then add 240g of urea, and add 24g of cetyltrimethylammonium bromide. After fully dissolving, add 1.9kg of activated alumina in batches, and stir to obtain a solid-liquid mixture. , the obtained slurry was sand-milled to obtain a slurry with an average particle size of 0.4 μm, and then the slurry obtained by sand-milling was transferred to a high-pressure reactor, and hydrothermally reacted at 150 ° C for 24 hours. After the reaction, the obtained slurry was separated from solid and liquid, fully Washing, spray drying to obtain pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

Embodiment 2

[0025] Add 260g of aluminum sulfate octadecahydrate to 10kg of deionized water, then add 80g of urea, and add 80g of polyethylene glycol-2000, after fully dissolving, add 1.2kg of activated alumina in batches, stir evenly to obtain a solid-liquid mixture, and carry out the obtained slurry Sand milling treatment to obtain a slurry with an average particle size of 1.5 μm, and then transfer the slurry obtained by sand milling to a high-pressure reactor, and conduct a hydrothermal reaction at 200 ° C for 8 hours. After the reaction, the obtained slurry is separated from solid and liquid, fully washed, and spray-dried to obtain Pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

Embodiment 3

[0029] Add 34g of aluminum sulfate octadecadecane to 10kg of deionized water, then add 12g of urea, and add 24g of sodium tartrate. After fully dissolving, add 0.5kg of activated alumina in batches, stir to obtain a solid-liquid mixture, and obtain a slurry with an average particle size of 12 μm. Then the obtained slurry was transferred to an autoclave for hydrothermal reaction at 250° C. for 1 hour. After the reaction, the obtained slurry was separated from solid to liquid, fully washed, and spray-dried to obtain pseudo-boehmite powder. The obtained powder is kneaded into a plastic body with 3% nitric acid as a binder, extruded, dried at 120°C, and calcined at 550°C to obtain a shaped carrier. The characterization results of pseudo-boehmite powder and molding carrier are listed in Table 1.

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