阅读说明：本技术 一种氧化铝载体及其制备方法 (Alumina carrier and preparation method thereof ) 是由 毛祖旺 乐毅 彭晖 铁锴 杨晨熹 易水生 刘海江 汪晓菁 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种氧化铝载体及其制备方法,在所述氧化铝载体中含有卤素元素、任选的Si元素、任选的La、Ce、Pr、Li、K、Ba元素中的一种或多种；所述氧化铝载体的比表面积为10～150m～(2)/g、堆密度为0.3～0.9g/mL、孔容为0.25～1.00mL/g。所述氧化铝载体通过对粉末状原料进行粉体混合、捏合成型和干燥焙烧得到,所述粉末状原料包括氧化铝粉末、任选的含Si化合物和任选的成型造孔剂,所述氧化铝粉末选自拟薄水铝石粉和任选的其它氧化铝粉,并且在制备过程中加有含卤素有机物。利用本发明所述方法得到高比表面积、高孔容、低堆密度等综合性能较好的氧化铝载体。(The invention discloses an alumina carrier and a preparation method thereof, wherein the alumina carrier contains one or more of halogen element, optional Si element, optional La, Ce, Pr, Li, K and Ba element; the specific surface area of the alumina carrier is 10-150 m 2 (iv) a bulk density of 0.3 to 0.9g/mL, and a pore volume of 0.25 to 1.00 mL/g. The alumina carrier is prepared by mixing powderThe material is obtained by powder mixing, kneading, molding, drying and roasting, wherein the powder material comprises alumina powder, optional Si-containing compound and optional molding pore-forming agent, the alumina powder is selected from pseudo-boehmite powder and optional other alumina powder, and halogen-containing organic matter is added in the preparation process. The alumina carrier with high specific surface area, high pore volume, low bulk density and other comprehensive performances is obtained by the method.)

1. An alumina carrier contains 0.01-3 wt% of halogen element, and the specific surface area is 10-150 m²(iv) a bulk density of 0.3 to 0.9g/mL, and a pore volume of 0.25 to 1.00 mL/g.

2. The alumina carrier according to claim 1,

the specific surface area of the alumina carrier is 10-100 m²(ii)/g, the bulk density is 0.4-0.9 g/mL, and the pore volume is 0.35-1.00 mL/g; and/or

The alumina carrier contains fluorine and/or chlorine; preferably, the fluorine element accounts for 0.01-1 wt% of the total mass of the carrier, and the chlorine element accounts for 0.01-2 wt% of the total mass of the carrier; more preferably, the fluorine element accounts for 0.01-0.7 wt% of the total mass of the carrier, and the chlorine element accounts for 0.01-1 wt% of the total mass of the carrier.

3. The alumina support according to claim 1 or 2,

the alumina carrier optionally contains Si element, and the Si element accounts for 0-1.5 wt% of the total weight of the carrier, and preferably 0-1 wt%; and/or

The alumina carrier optionally contains one or more of La, Ce, Pr, Li, K and Ba elements, and the mass of the one or more elements accounts for 0-1.5 wt% of the total mass of the carrier, preferably 0-1 wt%.

4. A method for preparing an alumina carrier, preferably for preparing an alumina carrier according to any one of claims 1 to 3, comprising the steps of:

(1) mixing the powder raw materials;

(2) adding the acidic aqueous solution into the powder for kneading and molding;

(3) drying and roasting to obtain the alumina carrier;

wherein a halogen-containing organic substance, preferably a fluorine-containing and/or chlorine-containing organic substance is added to the powdery raw material and/or the acidic aqueous solution.

5. The method according to claim 4, wherein in step (1), the powdery raw material comprises alumina powder, optionally a Si-containing compound, and optionally a shaped pore former, wherein the alumina powder is selected from pseudo-boehmite powder and optionally other alumina powder; preferably, the other alumina powder is selected from at least one of trihydrate alumina powder, fast deoxidized alumina powder and composite phase alumina powder; more preferably:

the amount of the alumina trihydrate accounts for 0-30 wt% of the total amount of the alumina powder; and/or

The dosage of the fast deoxidized aluminum powder accounts for 0-30 wt% of the total dosage of the aluminum oxide powder; and/or

The amount of the composite phase alumina is 0-30 wt% of the total amount of the alumina powder.

6. The preparation method according to claim 5, wherein the Si-containing compound is a water-insoluble Si-containing compound, preferably selected from at least one of but not limited to dry silica gel, nano-silica, and silicon carbide; preferably, the Si-containing compound is used in an amount of 0 to 1.35 wt% based on the total amount of the alumina powder, wherein the Si-containing compound is used in an amount based on the weight of Si element therein.

7. The preparation method according to claim 5, wherein the forming pore-forming agent is at least one selected from sesbania powder, starch, cellulose, high molecular polymer and decomposable alkaline substances, preferably, the forming pore-forming agent is used in an amount of 0-20 wt% of the total amount of the alumina powder; more preferably:

the cellulose is at least one selected from sesbania powder, starch, methyl cellulose, hydroxypropyl methyl cellulose and sodium hydroxymethyl cellulose; and/or the high molecular polymer is selected from at least one of polyethylene microspheres, polystyrene, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, polyethylene glycol and polyacrylate acrylic acid; and/or the decomposable alkaline substance is selected from at least one of urea, methylamine, ethylenediamine, ammonium carbonate and ammonium bicarbonate.

8. The production method according to claim 4, wherein, in the step (2),

the acidic aqueous solution is selected from at least one of hydrochloric acid aqueous solution, nitric acid aqueous solution, sulfuric acid aqueous solution, acetic acid aqueous solution, oxalic acid aqueous solution, citric acid aqueous solution, phosphoric acid aqueous solution and ammonium dihydrogen phosphate aqueous solution, and preferably from at least one of nitric acid aqueous solution, acetic acid aqueous solution, oxalic acid aqueous solution and citric acid aqueous solution; and/or

The weight ratio of the acidic aqueous solution to the powdery raw material is (0.5-5): 1, preferably (0.6-2): 1; and/or

Adding a soluble auxiliary agent into the acidic aqueous solution, wherein the soluble auxiliary agent is selected from at least one inorganic substance of La, Ce, Pr, Li, K and Ba, preferably, the soluble auxiliary agent is selected from at least one nitric compound and/or oxide of La, Ce, Pr, Li, K and Ba, more preferably, the amount of the soluble auxiliary agent is 0-1.35 wt% of the total amount of the alumina powder, and the amount of the soluble auxiliary agent is calculated by the weight of La, Ce, Pr, Li, K or Ba.

9. The production method according to claim 4, wherein, in the step (3),

the drying temperature is 60-150 ℃, and preferably 80-150 ℃; the drying time is 3-48 hours, preferably 5-25 hours; and/or

The roasting temperature is 800-1200 ℃, and preferably 900-1200 ℃; the roasting time is 3-48 hours, preferably 5-24 hours.

10. The production method according to claim 4,

the dosage of the fluorine-containing organic matter is 0.01-0.9 wt%, preferably 0.05-0.63 wt% of the total dosage of the alumina powder raw materials, wherein the dosage of the fluorine-containing organic matter is based on the weight of fluorine element in the fluorine-containing organic matter; and/or

The dosage of the chlorine-containing organic matter is 0.01-1.8 wt%, preferably 0.01-0.9 wt% of the total dosage of the powdery raw materials, wherein the dosage of the chlorine-containing organic matter is based on the weight of chlorine element in the powdery raw materials.

11. The method according to any one of claims 4 to 10, wherein the fluorine-containing and/or chlorine-containing organic substance is at least one selected from a fluorine-containing and/or chlorine-containing polymer powder, a fluorine-containing and/or chlorine-containing polymer suspension, and a fluorine-containing and/or chlorine-containing organic compound;

preferably, when the fluorine-containing and/or chlorine-containing organic matter is fluorine-containing and/or chlorine-containing polymer powder, it is added to the powdery raw material; when the fluorine-containing and/or chlorine-containing organic matter is a fluorine-containing and/or chlorine-containing polymer suspension, adding the fluorine-containing and/or chlorine-containing organic matter into the acidic aqueous solution; when the fluorine-containing and/or chlorine-containing organic compound is a fluorine-containing and/or chlorine-containing organic compound, adding the fluorine-containing and/or chlorine-containing organic compound into the acidic aqueous solution.

12. The production method according to claim 11,

the fluorine-containing and/or chlorine-containing polymer powder is selected from one or more of polytetrafluoroethylene powder, tetrafluoroethylene/hexafluoropropylene copolymer powder, tetrafluoroethylene/ethylene copolymer powder, polyvinylidene fluoride powder, polyvinyl fluoride powder, polychlorotrifluoroethylene powder, chlorotrifluoroethylene/ethylene copolymer powder, polyvinyl chloride powder, polyvinylidene chloride powder, chlorinated polypropylene powder, chlorinated polyethylene powder and vinyl chloride/vinylidene chloride copolymer powder; preferably, the fluorine-and/or chlorine-containing polymer powder has a particle diameter of less than 100 μm, preferably less than 50 μm; and/or

The suspension of fluorine-containing and/or chlorine-containing polymer is selected from polytetrafluoroethylene suspensions; and/or

The fluorine-containing and/or chlorine-containing organic compound is a water-soluble organic compound containing fluorine and/or chlorine elements, and preferably, the fluorine-containing and/or chlorine-containing organic compound is selected from at least one of, but not limited to, ethyl difluoroacetate, tetrafluoropropanol, trifluoroethanol, trifluoroacetaldehyde hydrate, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, and trichloroethanol.

13. An alumina carrier having a specific surface area of 10 to 150m obtained by the method according to any one of claims 4 to 12²(iv) per gram, bulk density of 0.3 to 0.9g/mL, pore volume of 0.25 to 1.00 mL/g.

Technical Field

The invention belongs to the field of catalyst carriers, and particularly relates to an alumina carrier.

Background

Alumina is an important catalyst carrier material and is widely applied to refining and processing of petroleum and production of chemical products. Primary alumina extracted from bauxite is not suitable for use in the preparation of catalyst supports because of its high impurity content, low specific surface area, small pore volume, etc. Generally, the aluminum oxide powder such as pseudo-boehmite powder, fast deoxidized aluminum powder and the like is obtained by refining. In order to meet the requirements of industrial use, the alumina carrier is also processed into shapes of spheres, tooth spheres, strips and the like and a certain size, and the alumina carrier can be obtained by uniformly mixing alumina powder and a forming aid, adding a peptizing agent, kneading, granulating, forming, drying and roasting.

The requirements of different application fields on the alumina carrier are different, for example, the alumina carrier with larger aperture, higher strength and higher acidity is used in the diesel oil hydrodesulfurization catalyst; the impurity removal catalyst for distillate oil hydrotreating needs an alumina carrier with high thermal stability and gradient acidity distribution; the alkyne and diene selective hydrogenation catalyst uses alumina carrier with large pore volume and low specific surface area. The physical property parameters of the alumina carrier can be adjusted by optimizing the refining process of the alumina carrier and optimizing the forming method of the alumina carrier, and a plurality of related researches are carried out.

CN106669645A discloses a method for preparing an alumina carrier, which is characterized in that macroporous alumina powder and small-pore alumina dry gel are mixed and kneaded for molding, wherein the small-pore alumina dry gel is prepared by respectively preparing alkaline aluminum salt solution and acidic aluminum salt solution containing anionic surfactant, carrying out neutralization reaction to obtain alumina slurry, aging, washing and drying to obtain the alumina carrier, and the alumina carrier has the characteristics of high acidity and low crystallinity.

CN109529827A discloses a method for preparing an alumina carrier, which is characterized in that components such as alumina powder, forming auxiliary agent and the like are prepared into suspension in deionized water, then acid solution is added, the suspension is stirred to form alumina slurry, the alumina slurry is dropped into one or more of liquid paraffin, vacuum pump oil and transformer oil, the mixture is formed at a specific temperature, and the alumina carrier is obtained after washing, drying and roasting.

In the prior art, the method for refining the alumina powder is improved, so that the problems of long preparation process and increased control factors exist; by improving the forming method, the problems of large change of physical property parameters and unstable carrier performance exist. The development of an alumina carrier which has simple preparation method, stable carrier performance and better comprehensive physical properties and is suitable for various catalytic reactions is still needed.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides an alumina carrier and a preparation method thereof, wherein a fluorine-containing and/or chlorine-containing organic compound, particularly a fluorine-containing and/or chlorine-containing high molecular compound is added in the preparation process, so that the pore structure of the alumina carrier can be effectively adjusted, and the alumina carrier is obtained.

One object of the present invention is to provide an alumina carrier having a specific surface area of 10 to 150m²(iv) per gram, bulk density of 0.3 to 0.9g/mL, pore volume of 0.25 to 1.00 mL/g.

In a more preferred embodiment, the alumina support has a specific surface area of 10 to 100m²(iv) per gram, bulk density of 0.4 to 0.9g/mL, pore volume of 0.35 to 1.00 mL/g.

In a preferred embodiment, the alumina support contains a halogen element.

In a further preferred embodiment, the halogen element is 0.01 to 3 wt% of the total weight of the alumina support.

In a preferred embodiment, the alumina support contains fluorine and/or chlorine.

In a further preferred embodiment, the fluorine element accounts for 0.01 to 1 wt% of the total mass of the carrier, and the chlorine element accounts for 0.01 to 2 wt% of the total mass of the carrier.

In a further preferred embodiment, the fluorine element accounts for 0.01 to 0.7 wt% of the total mass of the carrier, and the chlorine element accounts for 0.01 to 1 wt% of the total mass of the carrier.

In a preferred embodiment, the alumina support optionally contains Si element.

In a further preferred embodiment, the Si element accounts for 0 to 1.5 wt%, preferably 0 to 1 wt%, and more preferably 0 to 0.6 wt% of the total weight of the carrier.

In a preferred embodiment, one or more of La, Ce, Pr, Li, K and Ba elements are optionally contained in the alumina carrier, and the mass of the one or more elements accounts for 0-1.5 wt% of the total mass of the carrier, and is preferably 0-1 wt%.

Wherein, the elements such as La, Ce, Pr, Li, K, Ba and the like can further adjust parameters such as strength, specific surface area, pore volume and the like of the carrier.

In a preferred embodiment, the shape of the alumina carrier includes, but is not limited to, powder, granule, sphere, tablet, dentate sphere, strip, or heterotype strip such as clover.

The second purpose of the invention is to provide a preparation method of the alumina carrier, which comprises the following steps:

(1) mixing the powder raw materials;

(2) adding the acidic aqueous solution into the powder for kneading and molding;

(3) drying and roasting to obtain the alumina carrier;

wherein a halogen-containing organic substance, preferably a fluorine-containing and/or chlorine-containing organic substance is added to the powdery raw material and/or the acidic aqueous solution.

In a preferred embodiment, the amount of the fluorine-containing organic substance is 0.01 to 0.9 wt%, preferably 0.01 to 0.63 wt% of the total amount of the alumina powder-like raw material, wherein the amount of the fluorine-containing organic substance is based on the weight of fluorine element therein.

In a further preferred embodiment, the amount of the chlorine-containing organic compound is 0.01 to 1.8 wt%, preferably 0.01 to 0.9 wt% of the total amount of the powdery raw materials, wherein the amount of the chlorine-containing organic compound is based on the weight of chlorine element therein.

In a preferred embodiment, the fluorine-containing and/or chlorine-containing organic substance is selected from at least one of a fluorine-containing and/or chlorine-containing polymer powder, a fluorine-containing and/or chlorine-containing polymer suspension, and a fluorine-containing and/or chlorine-containing organic compound.

In a further preferred embodiment, when the fluorine-containing and/or chlorine-containing organic substance is a fluorine-containing and/or chlorine-containing polymer powder, it is added to the powdery raw material; when the fluorine-containing and/or chlorine-containing organic matter is a fluorine-containing and/or chlorine-containing polymer suspension, adding the fluorine-containing and/or chlorine-containing organic matter into the acidic aqueous solution; when the fluorine-containing and/or chlorine-containing organic compound is a soluble fluorine-containing and/or chlorine-containing organic compound, it is added to the acidic aqueous solution.

In the preparation method, the organic matter containing halogen is added to effectively adjust the pore structure of the alumina carrier. (1) Under the high-temperature condition, the organic matter containing halogen is decomposed in a gasification way to form a large number of micro-pores during roasting, part of fluorine and chlorine can form gas-phase compounds to be diffused and separated from the carrier, and part of the gas-phase compounds can be tightly combined with alumina and can be retained on the carrier; (2) the halogen enters the alumina framework, and alumina microcrystal is more easily converted into a flaky shape during high-temperature roasting, so that the pore structure of the alumina is influenced, the pore volume is generally promoted to be increased, the specific surface area is increased, and the bulk density is reduced; (3) in addition, halogen can exist in a doped form in a carrier, and the property of strong electronegativity of the halogen can influence the prepared oxygenThe surface of the aluminum oxide carrier is acidic, the halogen (especially fluorine atom and chlorine atom) on the aluminum oxide carrier can pull electrons on aluminum atoms and attract electrons of hydroxyl groups around the aluminum atoms, so that hydrogen protons on the hydroxyl groups are easier to ionize, and meanwhile, the halogen can cause the crystal structure of the carrier to be distorted to cause partial Al-OH polarization, and all the factors can promote the surface of the carrier to be polarizedAnd (4) forming acid sites.

Compared with the method that organic matters are respectively added to increase the pore volume and the specific surface area of the alumina carrier, inorganic matters added with fluorine and chlorine change the pore structure of the alumina, and the organic matters added with fluorine and/or chlorine can simultaneously act with fluorine and/or chlorine elements in the high-temperature roasting process of the alumina, so that the alumina carrier with better comprehensive performance is prepared, the addition times of the auxiliary agents are reduced, and the forming method is simplified.

In a preferred embodiment, the fluorine-and/or chlorine-containing polymer powder is selected from one or more of, but not limited to, polytetrafluoroethylene powder, tetrafluoroethylene/hexafluoropropylene copolymer powder, tetrafluoroethylene/ethylene copolymer powder, polyvinylidene fluoride powder, polyvinyl fluoride powder, polychlorotrifluoroethylene powder, chlorotrifluoroethylene/ethylene copolymer powder, polyvinyl chloride powder, polyvinylidene chloride powder, chlorinated polypropylene powder, chlorinated polyethylene powder, vinyl chloride/vinylidene chloride copolymer powder.

In a further preferred embodiment, the fluorine-and/or chlorine-containing polymer powder is selected from one or more of, but not limited to, polytetrafluoroethylene powder, tetrafluoroethylene/hexafluoropropylene copolymer powder, tetrafluoroethylene/ethylene copolymer powder, polyvinylidene fluoride powder, polyvinyl chloride powder, chlorinated polypropylene powder, chlorinated polyethylene powder.

In a further preferred embodiment, the fluorine-and/or chlorine-containing polymer powder has a particle diameter of less than 100. mu.m, preferably less than 50 μm, in order to facilitate uniform mixing with the alumina powder.

In a preferred embodiment, the fluorine-and/or chlorine-containing polymer suspension is selected from, but not limited to, polytetrafluoroethylene suspensions.

In a further preferred embodiment, the weight concentration of the fluorine-and/or chlorine-containing polymer suspension is from 20% by weight to 90% by weight, preferably from 40% by weight to 70% by weight.

In a preferred embodiment, the fluorine-and/or chlorine-containing organic compound is a water-soluble organic compound containing fluorine and/or chlorine elements.

In a further preferred embodiment, the fluorine-and/or chlorine-containing organic compound is selected from, but not limited to, at least one of ethyl difluoroacetate, tetrafluoropropanol, trifluoroethanol, trifluoroacetaldehyde hydrate, chloroacetic acid, dichloroacetic acid, trichloroacetic acid and trichloroethanol.

In a still further preferred embodiment, the fluorine-and/or chlorine-containing organic compound is selected from, but not limited to, at least one of tetrafluoropropanol, trifluoroethanol, chloroacetic acid, trichloroacetic acid and trichloroethanol.

In a preferred embodiment, in step (1), the powdered raw material comprises alumina powder, optionally a Si-containing compound, and optionally a shaped pore former, wherein the alumina powder is selected from pseudo-boehmite powder and optionally other alumina powder.

In a further preferred embodiment, the mass content of Na and Fe in the pseudo-boehmite powder is less than 0.1%, the mass reduction after high-temperature roasting is not higher than 40%, and the particle size of the powder is less than 200 μm.

In a still further preferred embodiment, the other alumina powder is selected from at least one of alumina powder trihydrate, fast deoxidized alumina powder, and composite phase alumina powder.

In a preferred embodiment, the alumina trihydrate is selected from at least one of gibbsite, bayerite, and nordstrandite.

In a further preferred embodiment, the alumina trihydrate is used in an amount of 0 to 30 wt%, preferably 0 to 20 wt%, based on the total amount of alumina powder.

In a preferred embodiment, the fast deoxidized aluminum powder is obtained by fast dehydration of aluminum hydroxide, wherein the weight content of Na and Fe is less than 0.1 wt%.

In a further preferred embodiment, the amount of the fast deoxidized aluminum powder is 0 to 30 wt%, preferably 0 to 20 wt%, of the total amount of the aluminum oxide powder.

In a preferred embodiment, the composite phase alumina is obtained by high temperature calcination of an aluminum hydroxide selected from the group consisting of alumina trihydrate or alumina monohydrate (e.g., gibbsite, bayerite, boehmite, etc.).

In a further preferred embodiment, the amount of the composite phase alumina is 0 to 30 wt%, preferably 0 to 20 wt%, based on the total amount of the alumina powder.

In a preferred embodiment, the Si-containing compound is a water-insoluble Si-containing compound, preferably selected from at least one of, but not limited to, dry silica gel, nano-silica, silicon carbide.

In a further preferred embodiment, the nano silica and dry silica gel have an average particle size of less than 120 nm.

In a further preferred embodiment, the amount of the Si-containing compound is 0 to 1.35 wt%, preferably 0 to 0.9 wt%, and more preferably 0 to 0.55 wt% of the total amount of the alumina powder, wherein the amount of the Si-containing compound is based on the weight of Si element therein.

In a preferred embodiment, the pore-forming agent is at least one selected from sesbania powder, starch, cellulose, high molecular organic polymer and decomposable alkaline substance.

In a further preferred embodiment, the cellulose is selected from at least one of methylcellulose, hydroxypropylmethylcellulose, sodium hydroxymethylcellulose; the high molecular polymer is selected from at least one of polyethylene microspheres, polystyrene, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, polyethylene glycol and polyacrylate acrylic acid; the decomposable alkaline substance is at least one selected from urea, methylamine, ethylenediamine, ammonium carbonate and ammonium bicarbonate.

In a further preferred embodiment, the amount of the shaped pore-forming agent is 0 to 20 wt%, preferably 0 to 15 wt%, of the total amount of the alumina powder.

In the step (1), the powder mixing may be performed in a dedicated mixer, or the powder may be added to a kneader and then dry-mixed without adding a solution for a certain time. The time required for mixing can be determined empirically by one skilled in the art. Powder mixing is an important step for preparing a carrier, and the uniform mixing of the powder can be ensured by optimizing the structure of a mixer, prolonging the mixing time and the like.

In a preferred embodiment, in the step (2), the acidic aqueous solution is at least one selected from the group consisting of an aqueous hydrochloric acid solution, an aqueous nitric acid solution, an aqueous sulfuric acid solution, an aqueous acetic acid solution, an aqueous oxalic acid solution, an aqueous citric acid solution, an aqueous phosphoric acid solution and an aqueous ammonium dihydrogen phosphate solution, and is preferably at least one selected from the group consisting of an aqueous nitric acid solution, an aqueous acetic acid solution, an aqueous oxalic acid solution and an aqueous citric acid solution.

In a further preferred embodiment, the concentration of the acidic aqueous solution is 0.1 to 10 wt%, preferably 0.1 to 5 wt%.

In a further preferred embodiment, in the step (2), the weight ratio of the acidic aqueous solution to the powdery raw material is (0.5-5): 1, preferably (0.6-2): 1.

The amount of the acid in the acidic aqueous solution can be adjusted by those skilled in the art according to the plasticity of the kneaded blank and the specific surface area, strength, bulk density and other data of the carrier after high-temperature roasting.

In a preferred embodiment, in step (2), a soluble auxiliary selected from at least one inorganic substance of La, Ce, Pr, Li, K and Ba is added to the acidic aqueous solution.

In a further preferred embodiment, the soluble auxiliary agent is selected from at least one nitrate compound and/or oxide of La, Ce, Pr, Li, K and Ba.

In a still further preferred embodiment, the amount of said soluble promoter is 0-1.35 wt% based on the total amount of said alumina powder. Wherein the soluble auxiliary agent is used in an amount based on the weight of La, Ce, Pr, Li, K or Ba.

In the step (2), the kneading molding is to add an acidic aqueous solution into the uniformly mixed powder, to mix and knead continuously, to react part of the alumina powder with acid to form a plastic blank, and to extrude and mold the blank into a required shape and size. The time for kneading and molding, the pressure for extrusion molding, and the like are related to the size of the equipment used, the composition of the alumina powder, the composition of the acid solution, and the like, and can be determined empirically by those skilled in the art.

In a preferred embodiment, in the step (3), the drying temperature is 60 to 150 ℃, and the drying time is 3 to 48 hours.

In a further preferred embodiment, in the step (3), the drying temperature is 80 to 150 ℃, and the drying time is 5 to 25 hours.

In a preferred embodiment, in the step (3), the roasting temperature is 800 to 1200 ℃, and the roasting time is 3 to 48 hours.

In a further preferred embodiment, in the step (3), the roasting temperature is 900 to 1200 ℃, and the roasting time is 5 to 24 hours.

In a more preferred embodiment, the heating rate is 30 to 150 ℃/hr when the firing is performed at 600 ℃ or lower, and the heating rate is 280 ℃/hr when the firing is performed at 600 ℃ or higher.

Wherein, the drying and roasting step is to dry, knead and shape the moisture in the green body, the solid phase reaction occurs in the high temperature roasting process, and the alumina particles are bonded together to form the alumina carrier with certain strength.

The preparation method of the alumina carrier is simple, the alumina carrier with different specific surface areas, pore volumes and bulk densities can be obtained by adjusting the type and content of fluorine-containing and/or chlorine-containing organic matters, the content of other additives, the molding roasting conditions and other parameters, and the preparation method is suitable for preparing various catalysts such as alkyne and diene selective hydrogenation catalysts, pyrolysis gasoline hydrogenation catalysts, olefin epoxidation catalysts, nitrite oxidative coupling catalysts and anthraquinone-process hydrogen peroxide production.

The third purpose of the present invention is to provide an alumina carrier obtained by the preparation method of the second purpose of the present invention, wherein the specific surface area of the alumina carrier is 10 to 150m²(iv) per gram, bulk density of 0.3 to 0.9g/mL, pore volume of 0.25 to 1.00 mL/g.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the invention, an organic matter containing halogen elements is added when the alumina carrier is prepared, and the organic matter is gasified and decomposed to form a large number of micropores during roasting, so that the pore structure of the alumina carrier is increased;

(2) according to the invention, when the alumina carrier is prepared, an organic matter containing halogen elements is added, halogen enters an alumina framework, and alumina micro-crystals are easily transformed into sheets during high-temperature roasting, so that the pore structure of alumina is influenced, the pore volume is generally promoted to be increased, the specific surface area is increased, and the bulk density is reduced;

(3) according to the invention, an organic matter containing halogen elements is added when the alumina carrier is prepared, the electronegativity of halogen is strong, the surface acidity of the prepared alumina carrier can be influenced, the halogen on the alumina carrier can pull electrons on aluminum atoms to attract electrons of hydroxyl groups around the aluminum atoms, so that hydrogen protons on the hydroxyl groups are ionized more easily, and a Bronsted acid site is formed;

(4) the alumina carrier with high specific surface area, high pore volume, low bulk density and other comprehensive performances is obtained by the method.

Detailed Description

While the present invention will be described in detail with reference to the following examples, it should be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the present invention.

The raw materials used in the examples and comparative examples are disclosed in the prior art if not particularly limited, and may be, for example, directly purchased or prepared according to the preparation methods disclosed in the prior art.

[ example 1 ]

1.00g of concentrated nitric acid, 3.00g of oxalic acid and 1.25g of trifluoroethanol are weighed and added into 210g of deionized water to prepare a mixed solution. Weighing 180g of pseudo-boehmite powder, 20g of fast deoxidized aluminum powder, 6g of sesbania powder, 5g of starch and 3g of crosslinked polyethylene microspheres with the particle size of about 40 mu m, uniformly mixing in a mixer, and transferring into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, baking at 1180 deg.C for 6hr, controlling heating rate at 600 deg.C or below 80 deg.C/hr and at 600 deg.C or above 200 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S1 with fluorine loading of about 0.5%.

[ example 2 ]

2.00g of concentrated nitric acid and 1.75g of cerous nitrate hexahydrate are weighed and added into 190g of deionized water to prepare a mixed solution. 200g of pseudo-boehmite powder, 8g of sesbania powder, 10g of starch and 0.48g of polyvinylidene fluoride powder are weighed, mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, calcining at 1170 deg.C for 6hr, controlling heating rate at 600 deg.C or below 100 deg.C/hr and at 600 deg.C or above 230 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S2 with fluorine loading of about 0.2% and Ce loading of about 0.4%.

[ example 3 ]

1.00g of concentrated nitric acid, 4.00g of acetic acid and 0.15g of 60% polytetrafluoroethylene concentrated dispersion are weighed and added into 190g of deionized water to prepare a mixed solution. 200g of pseudo-boehmite powder, 6g of sesbania powder and 6g of starch are weighed, mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, calcining at 1170 deg.C for 6hr, controlling heating rate at 600 deg.C or below 100 deg.C/hr and at 600 deg.C or above 200 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S3 with fluorine loading of about 0.05%.

[ example 4 ]

2.00g of concentrated nitric acid, 2.00g of acetic acid, 0.30g of 60% polytetrafluoroethylene concentrated dispersion and 3.03g of lanthanum nitrate hexahydrate are weighed and added into 180g of deionized water to prepare a mixed solution. 190g of pseudo-boehmite powder, 10g of alumina trihydrate, 8g of sesbania powder, 2g of hydroxymethyl cellulose, 3g of ammonium carbonate and 0.3g of nano silicon oxide with the average particle size of 75nm are weighed, mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 140 deg.C for more than 9hr, baking at 1190 deg.C for 6hr, controlling heating rate at 600 deg.C or below 100 deg.C/hr and at 600 deg.C or above 150 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S4 with fluorine loading of about 0.1%, La loading of about 0.7%, and Si loading of about 0.1%.

[ example 5 ]

1.00g of concentrated nitric acid, 3.00g of citric acid and 0.95g of 60% polytetrafluoroethylene concentrated dispersion are weighed and added into 180g of deionized water to prepare a mixed solution. Baking bayerite at 900 ℃ for 10 hours to obtain composite phase alumina of theta-alumina and alpha-alumina, weighing 20g of composite phase alumina, 180g of pseudo-boehmite powder, 6g of sesbania powder, 5g of urea and 0.93g of nano silica with the average particle size of 75nm, uniformly mixing in a mixer, and transferring into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 100 deg.C for more than 20hr, baking at 1100 deg.C for 6hr, controlling heating rate at 600 deg.C or below 100 deg.C/hr and at 600 deg.C or above 200 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S5 with fluorine loading of about 0.3% and Si loading of about 0.3%.

[ example 6 ]

3.00g of concentrated nitric acid and 0.73g of potassium nitrate were weighed and added to 200g of deionized water to prepare a mixed solution. 200g of pseudo-boehmite powder, 6g of sesbania powder, 6g of starch and 1.04g of K-value 72-71 polyvinyl chloride powder are weighed, mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, baking at 1195 deg.C for 6hr, controlling heating rate at 600 deg.C or below 100 deg.C/hr and at 600 deg.C or above 200 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier S6 with chlorine loading of about 0.4% and K loading of about 0.2%.

[ example 7 ]

2.00g of concentrated nitric acid, 2.00g of oxalic acid, 1.49g of tetrafluoropropanol and 0.81g of barium nitrate were weighed and added to 230g of deionized water to prepare a mixed solution. 160g of pseudo-boehmite powder, 40g of fast deoxidized aluminum powder, 8g of methyl cellulose, 7g of polyvinyl alcohol and 5g of ethylenediamine are weighed and mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 80 deg.C for more than 25hr, calcining at 1020 deg.C for 10hr, controlling heating rate at 600 deg.C or below 50 deg.C/hr and at 600 deg.C or above 150 deg.C/hr, and naturally cooling to room temperature to obtain the alumina carrier S7.

[ example 8 ]

1.00g of concentrated nitric acid, 3.00g of oxalic acid and 0.46g of chloroacetic acid are weighed and added into 210g of deionized water to prepare a mixed solution. Baking bayerite at 900 ℃ for 10 hours to obtain composite phase alumina of theta-alumina and alpha-alumina, weighing 40g of composite phase alumina, 160g of pseudo-boehmite powder, 6g of hydroxypropyl methyl cellulose, 5g of polyethylene oxide and 3g of urea, uniformly mixing in a mixer, and transferring into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 150 deg.C for more than 5hr, baking at 1180 deg.C for 4hr, controlling heating rate at 600 deg.C or below at 120 deg.C/hr and at 600 deg.C or above at 250 deg.C/hr, and naturally cooling to room temperature to obtain the alumina carrier S8.

Comparative example 1

The procedure of example 3 was repeated except that the dispersion was not concentrated with 0.15g of polytetrafluoroethylene under the same conditions, to obtain an alumina carrier D1.

Comparative example 2

The procedure of example 2 was repeated except for using 0.87g of potassium fluoride in place of 0.48g of polyvinylidene fluoride (both having the same fluorine content), and the same conditions were applied, to obtain an alumina support D2.

Comparative example 3

The procedure of example 1 was repeated except for using (2.19g of potassium fluoride and 1.7g of ethyl acetate) in place of 2.39g of ethyl difluoroacetate (both having the same fluorine content), and otherwise the same conditions were applied to obtain an alumina carrier D3.

Comparative example 4

2.50g of concentrated nitric acid is weighed and added into 190g of deionized water to prepare a mixed solution. 200g of pseudo-boehmite powder, 8g of sesbania powder, 3g of starch and 3g of crosslinked polyethylene microspheres with the particle size of about 40 mu m are weighed, uniformly mixed in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, baking at 1185 deg.C for 6hr, controlling heating rate at 300 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier D4.

Comparative example 5

3.00g of concentrated nitric acid and 0.30g of potassium chloride are weighed and added into 190g of deionized water to prepare a mixed solution. 200g of pseudo-boehmite powder, 8g of sesbania powder and 4g of starch are weighed, mixed uniformly in a mixer and transferred into a kneader. Slowly adding the mixed solution, fully kneading, extruding, molding and granulating to obtain particles with the particle size of 4-6 mm. Oven drying at 120 deg.C for more than 12hr, baking at 1195 deg.C for 6hr, controlling heating rate at 300 deg.C/hr, and naturally cooling to room temperature to obtain alumina carrier D5 with chlorine loading of about 0.1%.

Comparative example 6

The procedure of example 2 was repeated except for using 0.56g of ammonium fluoride in place of 0.48g of polyvinylidene fluoride (both having the same fluorine content), and the same conditions were used, to obtain an alumina support D6.

[ Experimental example 1 ]

The alumina supports prepared in the above examples and comparative examples were measured for specific surface area, bulk density and pore volume. Wherein the specific surface area is measured by adopting a nitrogen physical adsorption BET method; the bulk density is obtained by measuring the mass of 100mL of alumina carrier, and an average value is taken after each sample is measured for 3 times; the pore volume is measured by a mercury intrusion method, and is carried out by referring to a common alumina carrier pore volume measuring method. The results of the measurements are shown in Table 1 below.

Table 1:

as can be seen from Table 1, compared with comparative examples 1 to 6, the alumina carriers prepared by the method of the present invention in examples 1 to 8 have higher specific surface area and pore volume, and are favorable for preparing supported metal catalysts; meanwhile, the bulk density is reduced, and the using amount of the catalyst prepared by using the alumina carrier can be reduced under the condition of the same filling volume, so that the market competitiveness of the prepared catalyst is favorably improved.