Alumina carrier composition, alumina carrier and preparation method and application thereof

Abstract

The invention relates to the field of catalysts, and discloses an alumina carrier composition, an alumina carrier and a preparation method and application thereof, the alumina carrier composition contains pseudo-boehmite and fluoride, and does not contain acid with a pKa value of-16 to 4. The preparation method of the alumina carrier provided by the invention comprises the following steps: 1) performing first molding on the alumina carrier composition provided by the first aspect of the invention to obtain a first product; and (2) carrying out second forming and roasting on the first product obtained in the step (1) and a forming aid. According to the alumina carrier provided by the invention, a large amount of NOx or hydrogen chloride and other atmospheric pollutants cannot be formed in the preparation process, the alumina carrier is more environment-friendly and safer, and the side pressure strength and the specific surface area of the catalyst carrier can be increased.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and in particular to an alumina carrier composition, an alumina carrier, and a preparation method and application thereof. Background Art

[0002] Alumina is widely used as an adsorbent, catalyst and catalyst carrier in the chemical industry, environmental protection, automobile exhaust treatment, etc., especially as a catalyst carrier in the chemical industry.

[0003] In environmental protection and chemical industry, industrial catalysts are usually used in continuous flow gas-solid, liquid-solid, or gas-liquid-solid multiphase systems. In order to meet certain use requirements, alumina carriers are usually processed into spheres, cylinders, clover-shaped strips, Raschig rings, porous honeycombs or gears, and are required to have certain lateral pressure strength, specific surface area and pore structure. A large specific surface area is conducive to improving the activity of the catalyst, a high lateral pressure strength is for long-term use, and an appropriate pore structure is conducive to improving the selectivity of the target product in a parallel or serial reaction system.

[0004] There are three main methods for preparing alumina carriers: ① using pseudo-boehmite (monohydrated alumina) as the main raw material; ② using α-alumina trihydrate as the main raw material and pseudo-boehmite or aluminum sol as a binder; ③ using sintered α-alumina as the main raw material. In order to adjust the performance of the carrier, other additives such as combustible carbonaceous materials, mineralizers, and molding aids are also added during the preparation.

[0005] Alumina plants extract alumina from bauxite, and α-gibbsite is generally easily prepared through the Bayer process or the sintering process. Compared with pseudo-boehmite, α-alumina trihydrate has a wide source and a lower selling price, so from an economic point of view, the use of α-gibbsite has a greater cost advantage. When using α-gibbsite raw material to extrude and mold an alumina carrier, pseudo-boehmite and peptizing acids or aluminum sols are usually added as binders, otherwise it is difficult to mold. For pseudo-boehmite, it is often required to have a higher peptization index (generally required to be higher than 90%) so that it can peptize with acid to form aluminum sol to increase the strength of the carrier. Acids such as hydrochloric acid and nitric acid are commonly used peptizing agents. Due to the use of these acids, a large amount of NO will be formed in the subsequent roasting. x Or atmospheric pollutants such as hydrogen chloride, which are harmful to the environment. In actual use, the acid poses a potential risk of personal injury to operators. How to improve the environmental protection and safety of the alumina carrier preparation process is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0006] The purpose of the present invention is to provide an alumina carrier composition, an alumina carrier and a preparation method and application thereof. The alumina carrier composition does not contain an acid with a pKa value of -16 to 4, and does not generate NO during the preparation process of the alumina carrier. x Or atmospheric pollutants such as hydrogen chloride, and the prepared alumina carrier has high lateral pressure strength and large specific surface area, and has a regular appearance, safety and no pollution.

[0007] In order to achieve the above object, the first aspect of the present invention provides an alumina carrier composition, wherein the alumina carrier composition contains pseudo-boehmite, fluoride, and an acid with a pKa value of -16 to 4.

[0008] Preferably, the alumina carrier composition further contains one or more of component A, an alkaline earth metal compound and a silicon-containing compound.

[0009] Preferably, the A component is hydrated alumina and / or transition phase alumina; more preferably, the A component is α-gibbsite.

[0010] Preferably, the fluoride is a metal fluoride or ammonium fluoride, preferably a metal fluoride.

[0011] The metal fluoride is selected from one or more of aluminum fluoride, magnesium fluoride, calcium fluoride, strontium fluoride and barium fluoride, preferably aluminum fluoride.

[0012] Preferably, the alkaline earth metal compound is selected from one or more of a magnesium compound, a calcium compound, a strontium compound and a barium compound, preferably a calcium compound and / or a barium compound.

[0013] Preferably, the silicon-containing compound is selected from one or more of silica sol, silica gel and alkaline earth metal silicate.

[0014] Preferably, based on 100 parts by weight of the pseudo-boehmite, the content of the fluoride is 1.53-4.39 parts by weight, more preferably 1.5-3.9 parts by weight.

[0015] Preferably, based on 100 parts by weight of the pseudo-boehmite, the content of the component A is 0-152 parts by weight, the content of the alkaline earth metal compound is 0-0.77 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0-0.80 parts by weight;

[0016] More preferably, based on 100 parts by weight of the pseudo-boehmite, the content of component A is 59-138 parts by weight, the content of the alkaline earth metal compound is 0.3-0.7 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0.2-0.6 parts by weight.

[0017] Preferably, the particle size of the pseudo-boehmite is 100-1000 mesh, more preferably 150-600 mesh.

[0018] Preferably, the particle size of the A component is 100-600 mesh, more preferably 100-300 mesh.

[0019] A second aspect of the present invention provides a method for preparing an alumina carrier, wherein the method comprises the following steps:

[0020] 1) subjecting the alumina carrier composition according to the first aspect of the present invention to a first shaping step to obtain a first product;

[0021] 2) subjecting the first product obtained in step 1) to a second forming and calcining step with a forming aid.

[0022] Preferably, in step 1), the first molding method is compression molding and / or extrusion molding, preferably compression molding.

[0023] Preferably, step 1) further includes a step of drying the first molded product.

[0024] Preferably, the drying conditions include: a drying temperature of 50-120° C., and a drying time of 0.1-24 h; more preferably, the drying conditions include: a drying temperature of 60-100° C., and a drying time of 0.5-18 h.

[0025] Preferably, the method further comprises the steps of crushing and screening the first product before the second forming, and the particle size of the screened product is 10-200 mesh, more preferably 20-120 mesh.

[0026] Preferably, the weight ratio of the first product to the molding aid is 1:0.005-0.08, more preferably 1:0.015-0.06.

[0027] Preferably, the molding aid is selected from one or more of graphite, activated carbon and alkaline earth metal stearate, more preferably graphite and / or alkaline earth metal stearate.

[0028] Preferably, the second molding method is tableting.

[0029] Preferably, the calcination conditions include: heating to 1100-1500°C within 25-34 hours and keeping warm for 1-8 hours, and the total calcination time is 8-60 hours; more preferably, the calcination conditions include: heating to 1200-1400°C within 28-31 hours and keeping warm for 1-5 hours, and the total calcination time is 10-50 hours.

[0030] The third aspect of the present invention provides an alumina carrier, wherein the alumina carrier is prepared using the alumina carrier composition provided by the first aspect of the present invention or the alumina carrier preparation method provided by the second aspect of the present invention.

[0031] Preferably, the lateral pressure strength of the alumina carrier is above 70 N / cm and the specific surface area is 0.5-6 m 2 / g, a water absorption rate of 30-70%, and a silicon content of 0-3.0% by weight; more preferably, the lateral compression strength of the carrier is above 80N / cm, and the specific surface area is 1.0-5.0m 2 / g, water absorption is 30-60%, and silicon content is 0-2.0% by weight.

[0032] The fourth aspect of the present invention provides the use of the alumina carrier described in the third aspect of the present invention in the preparation of a catalyst. Preferably, the catalyst is one or more of a hydrocarbon conversion to synthesis gas catalyst, a methanation reaction catalyst, an alkyne selective hydrogenation catalyst and an olefin epoxidation reaction catalyst.

[0033] Through the above technical solution, the following technical effects can be achieved:

[0034] The components of the alumina carrier composition provided in the first aspect of the present invention do not contain an acid with a pKa value of -16 to 4. Therefore, when the alumina carrier composition provided in the first aspect of the present invention is used to prepare the alumina carrier, a large amount of NO is not formed during the preparation process. x Or atmospheric pollutants such as hydrogen chloride, and can also increase the lateral pressure strength of the catalyst carrier.

[0035] When an alumina carrier is prepared by the alumina carrier preparation method provided by the second aspect of the present invention, no environmentally harmful substances such as acids with a pKa value of -16 to 4 are added during the entire preparation process, thereby avoiding harm to operators caused by acids during the actual preparation process. This is not only environmentally friendly, but also can significantly improve the safety of the preparation process.

[0036] The alumina carrier provided in the third aspect of the present invention has a higher lateral pressure strength than the alumina carrier using an acid with a pKa value of -16 to 4, thereby increasing the lateral pressure strength of the catalyst carrier and extending the service life of the catalyst. The carrier has high strength and / or a large specific surface area, a regular appearance, and is formed by tableting, and its specific surface area can reach 1-10m 2 / g, the water absorption rate can be as high as over 30%.

[0037] The application of the alumina carrier provided in the fourth aspect of the present invention enables the alumina carrier to be used safely and environmentally friendly in various catalysts, and because the catalyst carrier of the alumina carrier has a higher lateral pressure strength, the durability of the catalyst carrier can be increased. DETAILED DESCRIPTION

[0038] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0039] A first aspect of the present invention provides an alumina carrier composition, wherein the alumina carrier composition contains pseudo-boehmite and fluoride, and does not contain an acid having a pKa value of -16 to 4.

[0040] In the prior art, since acid acts as a peptizing agent in the preparation process of alumina, acid must be used in the preparation process of alumina carrier. However, the use of acid leads to the formation of a large amount of atmospheric pollutants such as NOx or hydrogen chloride during the roasting process, which is detrimental to the environment and also poses a health hazard to the operators.

[0041] The inventors of the present invention have found through extensive research that, through a reasonable combination of composition and preparation method, the alumina carrier composition can be free of acids with a pKa value of -16 to 4. In this way, not only can the health hazards to the workers and the pollution to the environment during the production of the alumina carrier be avoided, but also the lateral pressure strength and specific surface area of ​​the prepared alumina carrier can be significantly improved.

[0042] In the present invention, the pKa value is the result of measurement at 25°C.

[0043] In the present invention, there is no particular limitation on the acid having a pKa value of -16 to 4, and it may be any acid commonly used in the art, such as nitric acid, sulfuric acid, hydrochloric acid, formic acid, and acetic acid.

[0044] In the present invention, the chemical formula of the pseudo-boehmite is AlOOH·nH2O, wherein n is 0.08-0.62. In addition, in the present invention, there is no particular limitation on its source, and it can be various common commercial products.

[0045] In addition, in the present invention, there is no special requirement for the particle size of the pseudo-boehmite, and various sizes commonly used in the art can be used. In order to improve the molding performance of the alumina carrier, preferably, the particle size of the pseudo-boehmite is 100-1000 mesh, more preferably 150-600 mesh.

[0046] According to the present invention, the fluoride can use a compound with a green and pollution-free preparation process, such as one or more of aluminum fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, and barium fluoride. In order to promote crystallization, increase the carrier's lateral pressure strength, specific surface area, and water absorption, thereby improving the activity of the catalyst, preferably, the fluoride is aluminum fluoride.

[0047] According to the present invention, there is no particular limitation on the contents of the pseudo-boehmite and fluoride, as long as the alumina carrier can be successfully prepared. In addition, the content of the fluoride can be limited according to the content of the pseudo-boehmite. Preferably, based on 100 parts by weight of the pseudo-boehmite, the content of the fluoride is 1.53-4.39 parts by weight, and more preferably 1.5-3.9 parts by weight.

[0048] According to the present invention, in order to improve the lateral compressive strength, specific surface area and water absorption rate of alumina, preferably, the alumina carrier composition further contains one or more of component A, alkaline earth metal compounds and silicon-containing compounds.

[0049] The A component is hydrated alumina and / or transition phase alumina.

[0050] According to the present invention, for the purpose of reducing costs, preferably, the A component is α-gibbsite.

[0051] In addition, in the present invention, the particle size of the component A is not particularly limited, as long as it can be successfully formed and the alumina carrier can be prepared. For example, the particle size of the component A can be 100-600 mesh, preferably 100-300 mesh.

[0052] According to the present invention, in order to improve the activity and resistance of the catalyst, the alkaline earth metal compound can be selected from one or more of magnesium compounds, calcium compounds, strontium compounds and barium compounds; preferably, the alkaline earth metal compound is a calcium compound and / or a barium compound.

[0053] According to the present invention, in order to improve the activity and tolerance of the catalyst and improve the catalytic efficiency of the catalyst, the silicon-containing compound can be selected from one or more of silica sol, silica gel and alkaline earth metal silicate.

[0054] According to the present invention, in order to obtain more excellent carrier side pressure strength, specific surface area and water absorption rate, preferably, based on 100 parts by weight of the pseudo-boehmite, the content of component A is 0-152 parts by weight, the content of the alkaline earth metal compound is 0-0.77 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0-0.80 parts by weight.

[0055] More preferably, based on 100 parts by weight of the pseudo-boehmite, the content of component A is 59-138 parts by weight, the content of the alkaline earth metal compound is 0.3-0.7 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0.2-0.6 parts by weight.

[0056] In addition, in the present invention, when wet granulation is adopted, the alumina carrier composition may further contain a solvent.

[0057] In the present invention, there is no particular limitation on the solvent, and it can be any solvent commonly used in the art for preparing alumina carriers, for example, the solvent can be one or more of water, acetone and ethanol; preferably, the solvent is water. Based on 100 parts by weight of the pseudo-boehmite, the content of the solvent is 0-120 parts by weight, preferably, the amount of the solvent is 1-105 parts by weight.

[0058] In addition, in the present invention, there is no particular limitation on the form in which the solvent is added, and the solvent can be added alone or mixed with other components in advance. For example, the solvent can be added in the form of an aqueous solution or sol of an alkaline earth metal, a silicon compound, or a fluoride.

[0059] A second aspect of the present invention provides a method for preparing an alumina carrier, wherein the method comprises the following steps:

[0060] 1) subjecting the alumina carrier composition according to the first aspect of the present invention to a first shaping and drying step to obtain a first product,

[0061] 2) subjecting the first product obtained in step 1) to a second forming and calcining step with a forming aid.

[0062] In the present invention, the preparation method of the alumina carrier does not include the step of adding an acid with a pKa value of -16 to 4, so no environmentally harmful products are produced, and the harm caused by the acid to the operators is avoided during the actual operation process. This is not only environmentally friendly, but also can significantly improve the safety of the preparation process.

[0063] According to the present invention, first, the alumina carrier composition described in the first aspect of the present invention is subjected to a first shaping.

[0064] Here, there is no particular limitation on the first molding method, and various conventional molding methods in the art may be used, such as press molding or extrusion molding, etc., preferably press molding.

[0065] In addition, in the present invention, it should be noted that in step 1), for the convenience of molding, when the water content of the first molded product obtained after the first molding is greater than or equal to 5 weight%, step 1) may also include a step of drying the first molded product.

[0066] According to the present invention, when the drying process is performed, the drying conditions may include: a drying temperature of 50-120°C and a drying time of 0.1-24h; preferably, the drying conditions include: a drying temperature of 60-100°C and a drying time of 0.5-18h.

[0067] According to the present invention, in order to facilitate the subsequent second molding, the preparation method of the alumina carrier also includes the steps of crushing and screening the first product before the second molding. When there is a first product that does not pass through the screen, further crushing and screening operations are performed to allow all the first products to pass through the screen.

[0068] According to the present invention, in order to facilitate the second forming, the particle size of the sieved product may be 10-200 meshes: preferably, the particle size of the sieved product is 20-120 meshes.

[0069] Next, the first product obtained in step 1) is subjected to a second molding process with a molding aid.

[0070] According to the present invention, in order to adjust the properties of the carrier and make it easy to shape, the molding aid can be selected from one or more of graphite, activated carbon and alkaline earth metal stearate; preferably, the molding aid is graphite and / or alkaline earth metal stearate.

[0071] According to the present invention, the amount of the molding aid can be selected according to the amount of the first product. For example, the weight ratio of the first product to the molding aid can be 1:0.005-0.08; preferably, the weight ratio of the first product to the molding aid is 1:0.015-0.06.

[0072] In the present invention, the second molding method is not particularly limited, and various molding methods commonly used in the art can be used. Preferably, the second molding is tableting.

[0073] In addition, in the second forming, the shape of the product formed by the sheeting can be any regular shape commonly used in the art, without special limitation, for example, it can be cylindrical, Raschig ring, honeycomb or wheel shape, etc.; preferably, the shape of the product formed by the sheeting is one or more of Raschig ring, honeycomb and wheel shape.

[0074] Next, the second molded product is calcined.

[0075] According to the present invention, the roasting conditions may include: heating to 1100-1500°C within 25-34 hours and keeping warm for 1-8 hours, and the total roasting time is 8-60 hours; preferably, the roasting conditions include: heating to 1200-1400°C within 28-31 hours and keeping warm for 1-5 hours, and the total roasting time is 10-50 hours.

[0076] The third aspect of the present invention provides an alumina carrier, wherein the alumina carrier is prepared using the alumina carrier composition described in the first aspect of the present invention or the alumina carrier preparation method described in the second aspect of the present invention.

[0077] According to the present invention, the lateral pressure strength of the carrier is above 70N / cm and the specific surface area is 0.5-6m 2 / g, water absorption rate is 30-70%, silicon content is 0-3.0 wt%; preferably, the lateral compression strength of the carrier is above 80N / cm, and the specific surface area is 1.0-5.0m 2 / g, water absorption is 30-60%, and silicon content is 0-2.0% by weight.

[0078] In addition, in the present invention, the main crystal phase of the alumina carrier is α-alumina.

[0079] In the present invention, the water absorption rate is tested by the following method: weigh a certain amount of carrier (mass is m1), boil it in boiling water for 1 hour, and then cool it naturally to room temperature. The carrier is taken out and placed upright on wet gauze with a water content of 50-80% to remove excess attached water on the surface of the carrier. Finally, the mass m2 of the carrier after absorbing water is weighed, and the water absorption rate of the carrier is calculated according to the formula "water absorption rate = (m2-m1) / m1×100%".

[0080] The term "water absorption rate" used in the present invention refers to the weight percentage (in %) of saturated adsorbed water per unit mass of a carrier at room temperature.

[0081] In the present invention, the specific surface area of ​​the alumina carrier provided in the third aspect of the present invention can reach 1-10m 2 / g, the water absorption rate is as high as over 30%, and compared with the acid-containing alumina carrier, it has higher lateral pressure strength, and its preparation process is more environmentally friendly and safe.

[0082] The fourth aspect of the present invention provides use of the alumina carrier described in the third aspect of the present invention in preparing a catalyst.

[0083] The catalyst may be any catalyst conventionally using an alumina carrier in the art, without particular limitation. For example, the catalyst may be one or more of a hydrocarbon conversion to synthesis gas catalyst, a methanation reaction catalyst, an alkyne selective hydrogenation catalyst, and an olefin epoxidation reaction catalyst.

[0084] In the present invention, the alumina carrier can be used in various catalysts in a more environmentally friendly and safe manner, and has a higher lateral pressure strength, and its specific surface area can reach 1-10m 2 / g, the water absorption rate can be as high as 30%, and it has a more excellent catalytic effect.

[0085] The present invention will be described in detail below by way of examples, but the present invention is not limited to the following examples.

[0086] In the following examples and comparative examples, the lateral compression strength is measured by an intelligent particle strength tester purchased from Dalian Chemical Research and Design Institute, model DLⅢ.

[0087] Method for determining carrier lateral compression strength: randomly select 20 carrier samples, measure the radial crushing strength, divide it by the particle length, and finally take the average value.

[0088] The specific surface area of ​​the carrier was determined by BET method using nitrogen physical adsorption.

[0089] Method for determining the water absorption rate of a carrier: Weigh a certain amount of a carrier (mass is m1), boil it in boiling water for 1 hour, and then cool it naturally to room temperature. Take out the carrier and stand it upright on wet gauze with an appropriate water content to remove excess water attached to the surface of the carrier. Finally, weigh the mass m2 of the carrier after it is saturated with water, and calculate the water absorption rate of the carrier according to the formula "water absorption rate = (m2-m1) / m1×100%".

[0090] The term "water absorption rate" used in the present invention refers to the weight percentage (in %) of saturated adsorbed water per unit mass of a carrier at room temperature.

[0091] α-Gibssite was purchased from Shandong Xiju Biotechnology Co., Ltd., model number c5626.

[0092] Pseudo-boehmite was purchased from Jinan Xiangfeng Weiye Chemical Co., Ltd. with model number 21645-51-2.

[0093] Silica aerosol was purchased from Cabot Corporation, model M-5.

[0094] Example 1

[0095] 1) 190 g of α-gibbsite passed through a 100-mesh sieve, 320 g of pseudo-boehmite passed through a 150-mesh sieve, 1.5 g of barium sulfate, 1.2 g of silica aerosol, and 9.0 g of aluminum fluoride were mixed uniformly, and then pressed into a block;

[0096] 2) The blocks obtained in the crushing step 1) are all passed through a 20-mesh sieve, and 16.2 g of graphite powder is added to the sieve undersize, mixed evenly, and pressed into Raschig ring-shaped particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm using a tablet press;

[0097] 3) The Raschig ring particles obtained in step 2) are placed in a high-temperature electric furnace, and the temperature is raised from room temperature to 1310° C. (the time required for the heating process is 30 hours), and then the temperature is kept constant for 3 hours to obtain the alumina carrier CARR1.

[0098] The crushing strength, specific surface area and water absorption rate were measured. The results are shown in Table 1.

[0099] Example 2

[0100] 1) 200 g of α-gibbsite passed through a 150-mesh sieve, 200 g of pseudo-boehmite passed through a 150-mesh sieve, 1.31 g of barium sulfate, 1.15 g of silica aerosol, 150 g of water and 7.7 g of aluminum fluoride were mixed uniformly, then pressed into a block, and dried in an oven at 80° C. for 10 h;

[0101] 2) The blocks obtained in the crushing step 1) are all passed through a 20-mesh sieve, 24.0 g of graphite powder is added to the sieve, the mixture is mixed evenly, and the mixture is pressed into Raschig ring-shaped particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm using a tablet press;

[0102] 3) The Raschig ring particles obtained in step 2) are placed in a high-temperature electric furnace, and the temperature is raised from room temperature to 1300° C. (the time required for the heating process is 29 hours), and then the temperature is maintained at a constant level for 3 hours to obtain the alumina carrier CARR2.

[0103] The crushing strength, specific surface area and water absorption rate were measured. The results are shown in Table 1.

[0104] Example 3

[0105] 1) 348 g of α-gibbsite with a mesh size of 200, 252 g of boehmite with a mesh size of 150, 1.3 g of powdered silica gel, 260 g of water and 8.8 g of aluminum fluoride were mixed evenly, then pressed into a block, and dried in an oven at 80°C for 10 h;

[0106] 2) The blocks obtained in the crushing step 1) are all passed through a 30-mesh sieve, 12 g of barium stearate is added to the sieve, the mixture is mixed evenly, and the mixture is pressed into Raschig ring-shaped particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm using a tablet press;

[0107] 3) The Raschig ring particles obtained in step 2) were then placed in a high-temperature electric furnace, heated from room temperature to 1310°C (the heating process took 30 hours), and then kept at a constant temperature for 3 hours to obtain an alumina carrier CARR3. The crushing strength, water absorption rate and specific surface area thereof were measured, and the results are shown in Table 1.

[0108] Example 4

[0109] 1) 245 g of α-gibbsite passed through a 150-mesh sieve, 245 g of pseudo-boehmite passed through a 150-mesh sieve, 7.8 g of aluminum fluoride, and 150 mL of water were mixed uniformly, then pressed into a block, and dried in an oven at 80° C. for 7 h to reduce the free water content to less than 5% by weight;

[0110] 2) Crushing the block obtained in step 1) and making it pass through a 20-mesh sieve. Add 12.8 g of graphite powder to the block under the sieve and mix them evenly. Use a tablet press to press the block into Raschig ring particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm.

[0111] 3) The Raschig ring particles obtained in step 2) were placed in a high-temperature electric furnace, heated from room temperature to 1300°C (the heating process took 31 hours), and then kept at a constant temperature for 3 hours to obtain a white alumina carrier CARR4. The crushing strength, specific surface area and water absorption rate were measured, and the results are shown in Table 1.

[0112] Example 5

[0113] 1) 500 g of pseudo-boehmite passed through a 150-mesh sieve and 8.3 g of aluminum fluoride were mixed evenly and then pressed into a block;

[0114] 2) The blocks obtained in the crushing step 1) are all passed through a 30-mesh sieve, 14 g of graphite powder is added to the sieve, the mixture is mixed evenly, and the mixture is pressed into Raschig ring-shaped particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm using a tablet press;

[0115] 3) The Raschig ring particles obtained in step 2) are placed in a high-temperature electric furnace, and the temperature is raised from room temperature to 1320° C. (the time required for the heating process is 28 hours), and then the temperature is kept constant for 3 hours to obtain a white alumina carrier CARR5.

[0116] The crushing strength, specific surface area and water absorption rate were measured. The results are shown in Table 1.

[0117] Example 6

[0118] 1) 220 g of α-gibbsite passed through a 150-mesh sieve, 280 g of pseudo-boehmite passed through a 150-mesh sieve, 1.45 g of barium sulfate, and 8 g of aluminum fluoride were mixed uniformly and then pressed into a block;

[0119] 2) Crushing the block obtained in step 1) and making it pass through a 20-mesh sieve. Add 15 g of graphite powder to the sieve and mix them evenly. Use a tablet press to press the block into Raschig ring particles with an outer diameter of 8 mm, an inner diameter of 3 mm, and a height of about 7 mm.

[0120] 3) The Raschig ring particles obtained in step 2) were placed in a high-temperature electric furnace, and the temperature was raised from room temperature to 1320°C over 30 hours (the time required for the heating process was 30 hours), and then kept at a constant temperature for 3 hours to obtain a white alumina carrier CARR6. The crushing strength, specific surface area and water absorption rate thereof were measured, and the results are shown in Table 1.

[0121] Comparative Example 1

[0122] The method of Example 1 is followed, except that step 1) further includes adding dilute nitric acid. The specific operation is as follows:

[0123] 1) 190 g of α-gibbsite passed through a 100 mesh sieve, 320 g of pseudo-boehmite passed through a 150 mesh sieve, 1.5 g of barium sulfate, 1.2 g of silica aerosol, and 9.0 g of aluminum fluoride were mixed uniformly, then transferred into a kneader, 100 mL of 20 wt % dilute nitric acid was added, kneaded for 25 min, extruded and cut into a ring body with an outer diameter of about 8.0 mm, a length of 7 mm, and an inner diameter of 3 mm, and dried at 80° C. for 10 h to reduce the free water content to less than 10 wt %, thereby obtaining an alumina carrier green body;

[0124] 2) The alumina carrier green body obtained in step 1) was placed in a high-temperature electric furnace, and the temperature was raised from room temperature to 1310°C over 30 hours, and the temperature was kept constant for 3 hours to obtain a white alumina carrier CARR7. Its crushing strength, specific surface area and water absorption were measured. The results are shown in Table 1.

[0125] Comparative Example 2

[0126] 1) 400 g of α-gibbsite having a diameter of 150 mesh and 150.0 g of pseudo-boehmite having a diameter of 150 mesh were placed in a mixer and mixed, then transferred to a kneader, 105 mL of 20 wt % dilute nitric acid was added, kneaded for 20 min, extruded and cut into a ring body with an outer diameter of about 8.0 mm, a length of 7.2 mm, and an inner diameter of 3.0 mm, and dried at 80° C. for 10 h to reduce the free water content to below 10 wt %, thereby obtaining an alumina carrier green body;

[0127] 2) The alumina carrier green body obtained in step 1) was placed in a high-temperature electric furnace, and the temperature was raised from room temperature to 1320°C over 30 hours, and the temperature was kept constant for 4 hours. The obtained white alumina carrier was named CARR8, and its crushing strength, water absorption rate and specific surface area were measured. The results are shown in Table 1.

[0128] Comparative Example 3

[0129] 400g of α-gibbsite with a mesh size of 150, 140.0g of pseudo-boehmite with a mesh size of 200, and 7.5g of aluminum fluoride were mixed in a mixer, and then transferred to a kneader, and 120ml of water was added. It was difficult to extrude and form. The obtained material was placed in a tray and dried at 80°C for 10h. The material was completely scattered and difficult to aggregate into granules, and could not be pressed into tablets.

[0130] Table 1

[0131] Sample No. Lateral compression strength(N) <![CDATA[Specific surface area (m 2 / g)]]> Water absorption (%) CARR1 166 1.82 48.0 CARR2 142 1.72 53.3 CARR3 135 1.71 51.5 CARR4 123 1.53 49.2 CARR5 130 1.60 46.2 CARR6 127 1.56 47.5 CARR7 118 1.48 45.2 CARR8 66 1.30 45.2 Comparative Example 3 Unable to form Unable to form Unable to form

[0132] By comparing Example 1 (CARR1) with Comparative Example 1 (CARR7), it can be concluded that the alumina carrier of the present invention not only has better lateral pressure strength, specific surface area and water absorption rate, but also avoids the use of nitric acid, reduces the environmental pollutant NO in the production process, and reduces the amount of water absorption. x The production process is more green and environmentally friendly.

[0133] By comparing Examples 1-3 (CARR1-CARR3) with Examples 4-6 (CARR4-CARR6), it can be concluded that the appropriate addition of alkaline earth metal compounds, silicon-containing compounds and / or fluorides can further increase the lateral pressure strength, specific surface area and water absorption, thereby improving the activity of the catalyst.

[0134] By comparing Example 4 (CARR4) with Comparative Example 3, it can be concluded that when the amount of hydrated alumina added exceeds the scope of the present invention and does not contain an auxiliary agent, the material is completely scattered and difficult to be pressed into tablets.

[0135] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An alumina carrier composition, characterized in that The alumina support composition contains pseudo-boehmite and fluoride and does not contain an acid having a pKa value of -16 to 4.

2. The alumina carrier composition according to claim 1, wherein The acid is an acid that acts as a peptizing agent.

3. The alumina carrier composition according to claim 1, wherein The alumina carrier composition further comprises one or more of component A, an alkaline earth metal compound and a silicon-containing compound; Preferably, the A component is hydrated alumina and / or transition phase alumina; More preferably, the A component is α-gibbsite.

4. The alumina carrier composition according to claim 1 or 2, wherein: The fluoride is a metal fluoride or ammonium fluoride, preferably a metal fluoride; The metal fluoride is selected from one or more of aluminum fluoride, magnesium fluoride, calcium fluoride, strontium fluoride and barium fluoride, preferably aluminum fluoride; Preferably, the alkaline earth metal compound is selected from one or more of a magnesium compound, a calcium compound, a strontium compound and a barium compound, more preferably a calcium compound and / or a barium compound; Preferably, the silicon-containing compound is selected from one or more of silicon oxide aerosol, powdered silica gel and alkaline earth metal silicate.

5. The alumina carrier composition according to claim 1 or 2, wherein: Based on 100 parts by weight of the pseudo-boehmite, the content of the fluoride is 1.53-4.39 parts by weight, more preferably 1.5-3.9 parts by weight; Preferably, based on 100 parts by weight of the pseudo-boehmite, the content of the component A is 0-152 parts by weight, the content of the alkaline earth metal compound is 0-0.77 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0-0.80 parts by weight; More preferably, based on 100 parts by weight of the pseudo-boehmite, the content of component A is 59-138 parts by weight, the content of the alkaline earth metal compound is 0.3-0.7 parts by weight, and the content of the silicon-containing compound calculated as silicon element is 0.2-0.6 parts by weight.

6. The alumina carrier composition according to claim 1 or 2, wherein: The particle size of the pseudo-boehmite is 100-1000 mesh, preferably 150-600 mesh; Preferably, the particle size of the A component is 100-600 mesh, more preferably 100-300 mesh.

7. A method for preparing an alumina carrier, characterized in that: The method comprises the following steps: 1) subjecting the alumina carrier composition according to any one of claims 1 to 6 to a first shaping step to obtain a first product; 2) subjecting the first product obtained in step 1) to a second forming and calcining step with a forming aid.

8. The preparation method according to claim 7, wherein: In step 1), the first molding method is compression molding and / or extrusion molding, preferably compression molding; Preferably, step 1) further comprises a step of drying the first molded product; Preferably, the drying conditions include: drying temperature of 50-120°C, drying time of 0.1-24h; More preferably, the drying conditions include: drying temperature of 60-100°C, drying time of 0.5-18h; Preferably, the method further comprises the steps of crushing and screening the first product before the second forming; Preferably, the particle size of the sieved product is 10-200 mesh, more preferably 20-120 mesh.

9. The preparation method according to claim 7, wherein: The molding aid is selected from one or more of graphite, activated carbon and alkaline earth metal stearate, more preferably graphite and / or alkaline earth metal stearate; Preferably, the weight ratio of the first product to the molding aid is 1:0.005-0.08, preferably 1:0.015-0.

06.

10. The preparation method according to claim 7, wherein: The second molding method is tableting; Preferably, the calcination conditions include: heating to 1100-1500°C within 25-34 hours and keeping the temperature for 1-8 hours, and the total calcination time is 8-60 hours; More preferably, the calcination conditions include: heating to 1200-1400° C. within 28-31 hours and keeping the temperature for 1-5 hours, and the total calcination time is 10-50 hours.

11. An alumina carrier, characterized in that: The alumina carrier is prepared using the alumina carrier composition described in any one of claims 1 to 6 or the alumina carrier preparation method described in any one of claims 7 to 10.

12. The alumina support according to claim 11, wherein The lateral pressure strength of the alumina carrier is above 90N / cm and the specific surface area is 0.5-6m 2 / g, water absorption rate is 30-70%, silicon content is 0-3.0% by weight; Preferably, the lateral pressure strength of the alumina carrier is above 95 N / cm and the specific surface area is 1.0-5.0 m 2 / g, water absorption is 45-70%, and silicon content is 0-2.0% by weight.

13. Use of the alumina carrier according to claim 11 or 12 in preparing a catalyst; Preferably, the catalyst is one or more of a hydrocarbon conversion to synthesis gas catalyst, a methanation reaction catalyst, an alkyne selective hydrogenation catalyst and an olefin epoxidation reaction catalyst.