Catalyst support, method for preparing the same, and use thereof

Abstract

The application relates to the field of carrier preparation, and discloses a catalyst carrier and a preparation method and application thereof, the specific surface area of the catalyst carrier is 20-200 m 2 / g, the pore volume is 0.1-0.7 mL / g; the average mechanical strength of the catalyst carrier is 18-110 N / mm; and the particle mechanical strength discrete coefficient of the catalyst carrier is in the range of 0-0.6. The catalyst carrier has a large specific surface area and pore volume, high average mechanical strength, and concentrated mechanical strength distribution.

Description

Technical Field

[0001] This invention relates to the field of support preparation, specifically to a catalyst support, its preparation method, and its application. Background Technology

[0002] Reactions such as catalytic oxidation, steam reforming, dry reforming, and methanation at medium and high temperatures present challenges such as high reaction temperatures, large heat fluxes, easy carbon deposition, and harsh hydrothermal environments. Catalysts used in these applications not only require high catalytic performance but also high requirements for thermal stability, hydrothermal stability, anti-carbon deposition properties, and mechanical strength.

[0003] The shape of a catalyst affects its strength, activity, resistance, and gas flow distribution, and is one of its important performance characteristics. Existing catalysts come in various shapes; for example, wheel-shaped and porous perforated catalysts are used for conversion, which increases the external surface area and activity while maintaining catalyst strength and reducing gas flow resistance. To further increase the external surface area of ​​such catalysts, the ribs and walls of irregularly shaped catalysts can be made thinner, but this leads to a decrease in mechanical strength and makes the catalyst more prone to breakage. Once broken, the small fragments can cause a sharp increase in resistance.

[0004] To better utilize catalyst performance, besides requiring superior physicochemical properties of the support (typically requiring a larger specific surface area, larger pore volume, more suitable pore size and surface properties, higher strength, etc.), the shape of the catalyst also plays a crucial role in engineering applications (heat transfer, mass transfer, pressure drop, etc.). Commonly used alumina shapes in industry include strip, column, ring, honeycomb, and spherical forms. Extrusion molding is a highly efficient and relatively inexpensive molding method. Fixed-bed systems have requirements for catalyst particle size; to reduce pressure drop, specific requirements are placed on the catalyst particle size and shape to ensure a high porosity in the catalyst bed after loading, thereby reducing pressure drop. While extrusion molding is relatively easy to achieve when producing a support of general strength by extruding materials with smaller particle diameters, obtaining a high-strength support by extruding larger particle diameters presents certain challenges.

[0005] Existing large particle supports are difficult to balance mechanical strength, specific surface area, and pore structure stability. There is an urgent need to develop a catalyst support that simultaneously possesses high mechanical strength, high specific surface area, and high pore volume. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of insufficient mechanical strength of large-particle catalyst supports in the prior art, which makes the prepared catalysts easy to break, have poor thermal stability and poor resistance to coking. The invention provides a catalyst support, its preparation method and application. The catalyst support has a large specific surface area and pore volume, high average mechanical strength and concentrated mechanical strength distribution.

[0007] To achieve the above objectives, a first aspect of the present invention provides a catalyst support, wherein the specific surface area of ​​the catalyst support is 20-200 m². 2 / g, pore volume is 0.1-0.7mL / g;

[0008] The average mechanical strength of the catalyst support is 18-110 N / mm;

[0009] The particle mechanical strength dispersion coefficient of the catalyst support is in the range of 0-0.6.

[0010] A second aspect of the present invention provides a method for preparing a catalyst support, wherein the method includes the following steps:

[0011] The catalyst support is obtained by mixing the precursor with a peptide solvent and a modifying agent, followed by molding, drying, and calcination.

[0012] Wherein, the temperature change of the material before and after molding is less than 20°C;

[0013] The modifying agent is selected from at least one of compounds containing alkali metal elements, alkaline earth metal elements, and rare earth metal elements.

[0014] The third aspect of the present invention provides a catalyst support prepared by the preparation method described in the second aspect.

[0015] The fourth aspect of this invention provides an application of the catalyst support described in the first or third aspect in the field of catalyst preparation.

[0016] The beneficial effects achieved through the above technical solution are as follows:

[0017] (1) The catalyst support provided by the present invention has a large specific surface area and pore volume, high average mechanical strength, and concentrated distribution of mechanical strength of the support;

[0018] (2) In this invention, during the preparation of the catalyst support, the addition of a modifying agent combined with molding conditions and control of material temperature changes before and after molding further improves the average mechanical strength of the catalyst support. The catalyst support is conducive to the loading and dispersion of active components. The prepared support has a large specific surface area and pore volume while ensuring concentrated distribution of mechanical strength. The preparation method is simple and stable to operate, easy to scale up industrially, has strong raw material adaptability, and is environmentally friendly. The catalyst prepared using the above support has high catalytic activity and selectivity. Attached Figure Description

[0019] Figure 1 This is an appearance diagram of the butterfly-shaped extruded strip obtained in Example 1;

[0020] Figure 2This is a schematic diagram showing the mechanical strength distribution of the catalyst supports in Examples 2, 6, and Comparative Example 3;

[0021] Figure 3 This is an appearance diagram of the Raschig ring extrusion strip obtained in Example 11;

[0022] Figure 4 These are the IR spectra of the extruded strips from Example 6 and Comparative Example 3. Detailed Implementation

[0023] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] The first aspect of this invention provides a catalyst support, wherein the specific surface area of ​​the catalyst support is 20-200 m². 2 / g, pore volume is 0.1-0.7mL / g;

[0025] The average mechanical strength of the catalyst support is 18-110 N / mm;

[0026] The particle mechanical strength dispersion coefficient of the catalyst support is in the range of 0-0.6.

[0027] In this invention, the catalyst support has a high specific surface area and high pore volume, while ensuring high average mechanical strength, and the mechanical strength of the support is concentrated.

[0028] In this invention, the dispersion coefficient refers to the mechanical strength dispersion of the catalyst support particles, which is the ratio of the standard deviation of the mechanical strength values ​​of a set of catalyst support particles to their average value. The number of catalyst support particles is n, which is 15-30, and the dispersion coefficient of the mechanical strength of the catalyst support particles is in the range of 0-0.6.

[0029] According to the present invention, preferably, the particle mechanical strength dispersion coefficient of the catalyst support is in the range of 0-0.6, for example, 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, or any range between the two, preferably in the range of 0-0.55.

[0030] In this invention, the average mechanical strength refers to the average value calculated from the compressive strength tested on 22 catalyst support particles. The compressive strength is obtained by measuring the crushing mechanical strength.

[0031] According to the present invention, preferably, the average mechanical strength of the catalyst support is 18-110 N / mm, for example, 18 N / mm, 20 N / mm, 22 N / mm, 24 N / mm, 28 N / mm, 32 N / mm, 36 N / mm, 40 N / mm, 48 N / mm, 56 N / mm, 60 N / mm, 70 N / mm, 80 N / mm, 90 N / mm, 100 N / mm, 110 N / mm, or any range between the two, preferably 20-100 N / mm, more preferably 30-80 N / mm.

[0032] According to the present invention, the type of catalyst support is not particularly limited, as long as the specific surface area, pore volume, and average mechanical strength of the support meet the defined range. Preferably, the catalyst support is selected from at least one of alumina, silicon dioxide, zirconium oxide, titanium dioxide, magnesium oxide, calcium oxide, zinc oxide, silicon nitride, silicon carbide, and carbon materials, and is preferably alumina. In the present invention, preferably, the mass percentage of alumina in the catalyst support is not less than 60 wt%, and more preferably 65-98 wt%.

[0033] According to the present invention, preferably, the specific surface area of ​​the catalyst support is 20-200 m². 2 / g, for example 20m 2 / g、25m 2 / g、30m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g, 100m 2 / g、110m 2 / g、120m 2 / g, 140m 2 / g, 160m 2 / g、180m 2 / g、200m 2 / g, or any range between the two, preferably 25-190m 2 / g.

[0034] According to the present invention, preferably, the pore volume of the catalyst support is 0.1-0.7 mL / g, for example, 0.1 mL / g, 0.15 mL / g, 0.2 mL / g, 0.25 mL / g, 0.3 mL / g, 0.35 mL / g, 0.4 mL / g, 0.45 mL / g, 0.5 mL / g, 0.55 mL / g, 0.6 mL / g, 0.65 mL / g, 0.7 mL / g, or any range between the two, preferably 0.2-0.65 mL / g. In the present invention, the specific surface area and pore volume of the catalyst support are measured by the BET low-temperature nitrogen adsorption method.

[0035] According to the present invention, the particle diameter of the catalyst support is not particularly limited. Preferably, the particle diameter of the catalyst support is 3-20 mm, more preferably 3.5-17 mm. It is easier to obtain high mechanical strength by molding a catalyst support with a smaller particle diameter; the larger the particle diameter of the catalyst support, the more difficult it is to improve the mechanical strength. In the present invention, the catalyst support maintains high specific surface area, high pore volume, and high mechanical strength while having a large particle diameter.

[0036] In this invention, the particle diameter of the catalyst support is measured by measuring the diameter of the circumscribed circle of the support cross-section.

[0037] The catalyst support material provided by this invention has high mechanical strength and various shapes and options, which can increase the surface area of ​​the catalyst, reduce airflow resistance, thereby improving catalyst performance and reducing plant operating energy consumption and costs.

[0038] A second aspect of the present invention provides a method for preparing a catalyst support, wherein the method includes the following steps:

[0039] The catalyst support is obtained by mixing the precursor with a peptide solvent and a modifying agent, followed by molding, drying, and calcination.

[0040] Wherein, the temperature change of the material before and after molding is less than 20°C;

[0041] The modifying agent is selected from at least one of compounds containing alkali metal elements, alkaline earth metal elements, and rare earth metal elements.

[0042] In this invention, the molding temperature is controlled within a relatively low range to avoid uneven heating of the outer surface and interior of the molded product particles due to molding at higher temperatures, resulting in excessively high outer surface temperatures and excessively low internal temperatures, which reduces the mechanical strength of the prepared catalyst support. The preparation method is simple and stable to operate, easy to scale up industrially, has strong raw material adaptability, and is environmentally friendly.

[0043] According to the present invention, preferably, the temperature change of the material before and after molding is less than 20°C, more preferably less than 18°C, and even more preferably less than 10°C. In this invention, controlling the temperature change of the material before and after molding to be small ensures that the material is heated uniformly during the molding process, which helps to improve the average mechanical strength of the catalyst support. In this invention, when the catalyst support is prepared through multiple molding processes, the temperature change of the material before and after molding refers to the temperature change of the material before and after the final molding.

[0044] According to the present invention, preferably, the mixing includes dry mixing, kneading, and / or rolling. Preferably, the conditions for kneading and / or rolling include: a kneading and / or rolling time of 5-180 min, more preferably 20-160 min.

[0045] According to the present invention, preferably, the molding conditions include: a molding temperature of 1-60°C, more preferably 5-50°C; and a molding pressure of 3-20 MPa, more preferably 4-15 MPa.

[0046] According to a preferred embodiment of the present invention, the mixing process includes: dry mixing the carrier precursor with modified auxiliary oxide, optional extrusion aid, optional binder and optional lubricant for a certain period of time, then adding an aqueous solution containing modified auxiliary and adhesive solvent, and mixing the above raw materials uniformly by kneading and / or rolling.

[0047] In this invention, the modifying agent is an agent capable of modulating the physical properties of the support and increasing its alkalinity. The modifying agent can be added directly to the support precursor in the form of a metal oxide, or it can be dissolved in water as a metal compound and then added to the support precursor, or it can be added to the catalyst support through impregnation. The inventors of this invention have discovered that by adding a peptizing solvent and suitable modifying agents during molding, combined with appropriate molding conditions, a high-strength support with a large specific surface area and pore volume can be obtained.

[0048] According to the present invention, preferably, the modifying agent is selected from at least one of compounds containing alkali metal elements, alkaline earth metal elements, transition metal elements and rare earth metal elements, and more preferably from at least one of oxides, acetates, nitrates, hydroxides, carbonates and basic carbonates of alkali metal elements, alkaline earth metal elements, transition metal elements and rare earth metal elements.

[0049] According to the present invention, preferably, the modifying agent is selected from at least one of nitrates, oxides and acetates of alkali metal elements, alkaline earth metal elements and rare earth metal elements, and more preferably from at least one of lanthanum nitrate, magnesium nitrate, zinc nitrate, potassium nitrate, magnesium oxide, calcium oxide, lanthanum acetate and magnesium acetate.

[0050] In this invention, preferably, the carrier and the modifying agent are of different types.

[0051] According to the present invention, preferably, the amount of the modifying agent added relative to 100 parts by weight of the carrier precursor is 0.6-15 parts by weight, for example, 0.6 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 6 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 14 parts by weight, 15 parts by weight, or any range between the two, preferably 0.8-12 parts by weight. Insufficient addition of the modifying agent will not achieve the effect of modulating the physical properties of the carrier and increasing the alkalinity of the carrier; excessive addition of the modifying agent will affect the mechanical strength of the catalyst carrier and reduce the specific surface area of ​​the carrier.

[0052] According to the present invention, preferably, the process of adding water after adding the modifying agent is also included. The volume of water added is 0.5-1.5 mL, preferably 0.65-1.2 mL, based on the weight of 1 g of the carrier precursor.

[0053] According to the present invention, preferably, the carrier precursor is a substance that is converted into a carrier through subsequent calcination. In the present invention, the source of the carrier precursor is not particularly limited; those skilled in the art can choose conventional carrier precursors, which can be commercially available or prepared by existing methods, as long as they can be converted into a carrier after calcination.

[0054] In this invention, preferably, the carrier precursor is selected from at least one of alumina, metallic aluminates, silicon dioxide, aluminosilicates, silicate minerals, titanium dioxide, zirconium oxide, magnesium oxide, zinc oxide, silicon nitride, silicon carbide, and carbon materials. The alumina may be hydrated alumina and / or alumina colloid, and the aluminosilicate may be zeolite and / or kaolin.

[0055] According to the present invention, preferably, the carrier precursor is selected from at least one of boehmite, calcium oxide and magnesium oxide.

[0056] According to the present invention, preferably, the carrier is selected from at least one of alumina, silicon dioxide, zirconium oxide, titanium dioxide, magnesium oxide, calcium oxide, zinc oxide, silicon nitride, silicon carbide, and carbon materials.

[0057] In this invention, preferably, alumina has the characteristics of large specific surface area, controllable pore structure, good thermal stability and strong adsorption capacity. Using boehmite as a precursor to prepare the catalyst support, the resulting catalyst support has a higher specific surface area and pore volume, which is beneficial to the loading and dispersion of active components. Further preparation of the catalyst results in higher catalytic activity.

[0058] According to the present invention, preferably, the colloidal solvent is an organic acid and / or an inorganic acid, more preferably selected from at least one of nitric acid, aluminum nitrate, acetic acid, and citric acid, and more preferably a mixture of nitric acid and aluminum nitrate and / or citric acid. In the present invention, the addition of the colloidal solvent enables sufficient colloidal dissolution between the precursor particles, improving the mechanical strength of the formed catalyst support and improving the pore structure. In the present invention, the type of colloidal solvent is not particularly limited, and it can be any colloidal solvent conventionally used in the art.

[0059] According to the present invention, preferably, the amount of the adhesive solvent added is 0.4-10 parts by weight, more preferably 0.6-8 parts by weight, relative to 100 parts by weight of the carrier precursor. In this invention, controlling the amount of adhesive solvent added within the above range avoids insufficient addition of adhesive solvent, resulting in inadequate dissolution of the catalyst carrier, and excessive addition of adhesive solvent, leading to excessive acidity of the catalyst carrier and weakened mechanical strength.

[0060] In this invention, the above-mentioned modified additives are used in combination with the carrier precursor and the colloidal solvent to improve the stability of the carrier precursor, making it less prone to phase transformation after calcination. This helps to increase the specific surface area and pore volume of the catalyst support without affecting the mechanical strength.

[0061] According to the invention, preferably, the mixture also includes optional extrusion aids, optional binders, and optional lubricants.

[0062] In this invention, unless otherwise specified, "optional" means containing or not containing, adding or not adding, or using or not using. Specifically, this invention may or may not include a squeezing aid. There are no particular limitations on the method of adding the additives; they may be added separately or together.

[0063] According to the present invention, the type of extrusion aid is not particularly limited, and can be a conventional extrusion aid in the art, preferably guar gum powder and / or cellulose. The amount of the extrusion aid is not particularly limited, and those skilled in the art can make adaptive adjustments as needed to ensure smooth subsequent molding. Preferably, the amount of the extrusion aid added relative to 100 parts by weight of the carrier precursor is 0-8 parts by weight, more preferably 0-6 parts by weight.

[0064] In this invention, preferably, the binder is an inorganic binder and / or an organic binder. The binder can function as a binder for the carrier precursor particles.

[0065] In this invention, the type of inorganic binder is not particularly limited and can be any conventional inorganic binder in the art. Preferably, the inorganic binder is selected from at least one of cement, alumina sol, silica sol, zirconium sol, and titanium sol.

[0066] In this invention, the type of organic binder is not particularly limited and can be any conventional organic binder in the art. Preferably, the organic binder is selected from at least one of methylcellulose, ethylcellulose, hydroxypropylcellulose, hydroxypropyl methylcellulose, and microcrystalline cellulose.

[0067] According to the present invention, the amount of adhesive used is not particularly limited, and those skilled in the art can adapt the addition of adhesive and the amount of adhesive added according to the mixing situation. Preferably, the amount of adhesive added is 0-4 parts by weight, more preferably 0-3 parts by weight, relative to 100 parts by weight of the carrier precursor.

[0068] According to the present invention, the type of lubricant is not particularly limited and can be any conventional lubricant in the art. Those skilled in the art can select the type and amount of lubricant according to the molding effect. Preferably, the lubricant is selected from at least one of glycerin, polyol, polyester, magnesium stearate, stearic acid, talc, and graphite.

[0069] According to the present invention, preferably, the amount of lubricant added is 0-10 parts by weight, more preferably 0-5 parts by weight, relative to 100 parts by weight of the carrier precursor. In the present invention, the addition of lubricant has a lubricating effect, which facilitates the smooth progress of molding and, combined with the molding conditions, can improve the average mechanical strength of the catalyst carrier.

[0070] According to a preferred embodiment of the present invention, the mixing process includes: dry mixing the carrier precursor with modified auxiliary oxide, optional extrusion aid, optional binder and optional lubricant for a certain period of time, then adding an aqueous solution containing modified auxiliary and adhesive solvent, and mixing the above raw materials uniformly by kneading and / or rolling.

[0071] In this invention, preferably, the ratio of the total mass of water added during the mixing process to the weight of the carrier precursor is 0.5-2.5:1, more preferably 0.6-2:1, and even more preferably 0.65-1.6:1.

[0072] According to a preferred embodiment of the present invention, the molding method is selected from at least one of extrusion molding, compression molding, and ball forming. Those skilled in the art can choose conventional molding equipment to perform the molding.

[0073] In this invention, preferably, extrusion molding is used to obtain a catalyst support with high specific surface area and pore volume while also having high mechanical strength, resulting in high preparation efficiency.

[0074] In this invention, the shape of the product obtained by extrusion molding is not particularly limited. Preferably, it is selected from at least one of butterfly, cylindrical, cloverleaf, honeycomb, Raschig ring, and porous irregular shapes. In this invention, the shape of the molded product is preferably Raschig ring and / or butterfly, which has better thermal conductivity, so that the catalyst support is heated more uniformly during the molding process.

[0075] In this invention, the material before molding also includes optionally mixing the already molded substandard material with water, mixing it evenly by kneading and / or rolling, and then performing final molding. In this invention, mixing the molded product again helps to improve the product qualification rate. The substandard material refers to undried molded strips with rough surfaces, incomplete shapes, and an average mechanical strength below 20 N / mm after random sampling and baking.

[0076] In this invention, preferably, the product is dried before calcination. The drying conditions are not particularly limited, and those skilled in the art can choose conventional drying methods and conditions. Preferably, the drying conditions include: a drying temperature of 30-180℃, more preferably 45-160℃, and more preferably 70-140℃; and a drying time of 0.5-100 hours, more preferably 1-80 hours, and more preferably 2-70 hours.

[0077] According to a preferred embodiment of the present invention, the drying process includes: drying at 30-70°C for 2-50 hours, and then drying at 100-150°C for 2-20 hours.

[0078] According to the present invention, preferably, the calcination conditions include: a calcination temperature of 700-1350℃, more preferably 750-1250℃; a calcination time of 1-8 hours, more preferably 2-6 hours; and a heating rate of 1-8℃ / minute, more preferably 2-6℃ / minute. In the present invention, high-temperature calcination under the above conditions yields a catalyst support with a high specific surface area.

[0079] The third aspect of the present invention provides a catalyst support prepared by the preparation method described in the second aspect.

[0080] The catalyst support prepared by the method of the present invention has an increased specific surface area and pore volume, which is beneficial to the loading and dispersion of active components, and enables the catalyst prepared using the support provided by the present invention to have higher catalytic activity and selectivity.

[0081] The fourth aspect of this invention provides an application of the catalyst support described in the first or third aspect in the field of catalyst preparation.

[0082] In this invention, the catalyst support is prepared by loading the catalytically active component using conventional methods in the field of catalyst preparation. The method is selected from at least one of metal vapor deposition, coating, impregnation, permeation, precipitation of catalytically active compositions, disc coating, and slurry impregnation (dip coating). The impregnation, precipitation, and disc coating methods are suitable for preparing catalysts whose active component is a soluble metal compound, including at least one of metal nitrates, metal halides, metal carboxylates, and metal sulfates. The slurry impregnation method is suitable for preparing catalysts whose active component is an insoluble metal compound, including metals and / or metal oxides.

[0083] In this invention, the metal element in the catalyst active component is selected from at least one of alkali metal elements, alkaline earth metal elements, transition metal elements, rare earth metal elements, and noble metal elements.

[0084] The present invention will be described in detail below through examples and comparative examples. Unless otherwise specified, all reagents used in the following examples and comparative examples are commercially available.

[0085] The screw extruder was purchased from the South China University of Technology Science and Technology Industrial Plant, model F-26;

[0086] The test methods and conditions for the specific surface area, pore volume, particle diameter and average mechanical strength of the catalyst support are described in the aforementioned specification and will not be repeated here.

[0087] Example 1

[0088] (1) Prepare the colloidal solvent solution by weighing 2g of citric acid and 6g of lanthanum nitrate, adding 156mL of water and 1.6g of nitric acid with a mass concentration of 63%, and stirring to dissolve.

[0089] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis) and 6g of guar gum powder were dry-mixed for 10 min. Then, the prepared peptizing solvent solution was added to the dry powder, and the mixture was kneaded for 10 min and then rolled for 40 min to mix evenly. The mixture was then extruded into 4 mm butterfly strips on a screw extruder. The molding temperature was controlled at 45℃ and the molding pressure was 6.5 MPa to obtain the molded product. The temperature change of the material before and after molding was 11℃. The molded product prepared above was dried at 120℃ for 4 hours and calcined at 960℃ for 4 hours with a heating rate of 4℃ / min to obtain catalyst support A1. Figure 1 This is an appearance diagram of the butterfly-shaped extruded strip obtained in Example 1.

[0090] Comparative Example 1

[0091] The catalyst support was prepared according to the method of Example 1, except that the dry mixing time was 2 min and the rolling time was 10 min. Then, it was shaped according to the method of Example 1, and the shaping conditions were kept consistent. Then, it was dried and calcined to obtain catalyst support D1.

[0092] Comparative Example 2

[0093] The catalyst support was prepared according to the method of Example 1, except that the temperature change before and after molding in step (2) was 30°C, and the catalyst support D2 was obtained.

[0094] Example 2

[0095] (1) Prepare the colloidal solvent solution by weighing 3g citric acid, 2g zinc nitrate, and 2g potassium nitrate, adding 166mL water and 1.6g nitric acid with a mass concentration of 63%, and stirring to dissolve.

[0096] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis) and 6g of guar gum powder were dry-mixed for 10 min. Then, the prepared peptizing solvent solution was added to the dry powder, and the mixture was kneaded for 20 min and then rolled for 40 min to mix evenly. The mixture was then extruded into 4 mm butterfly strips on a screw extruder. The molding temperature was controlled at 50℃ and the molding pressure was 6 MPa to obtain the molded product. The temperature change of the material before and after molding was 11℃. The molded product prepared above was dried at 120℃ for 4 hours and calcined at 960℃ for 4 hours with a heating rate of 4℃ / min to obtain catalyst support A2.

[0097] Example 3

[0098] (1) Prepare the gel solvent solution by weighing 11.12g aluminum nitrate and 5g magnesium nitrate, adding 165mL of water, and stirring to dissolve.

[0099] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis) and 6g of guar gum powder were dry-mixed for 10 min. Then, the prepared peptizing solvent solution was added to the dry powder, and the mixture was kneaded for 20 min and then rolled for 50 min. The resulting material was extruded into 4 mm butterfly strips on a screw extruder. The molding temperature was controlled at 45℃ and the molding pressure at 8 MPa to obtain the molded product. The temperature change of the material before and after molding was 7℃. The molded product prepared above was dried at 120℃ for 4 hours and calcined at 1000℃ for 4 hours at a heating rate of 4℃ / min to obtain catalyst support A3.

[0100] Example 4

[0101] (1) Prepare the colloidal solvent solution by weighing 2.4g of 63% nitric acid, adding 4g of glycerol, 2g of potassium nitrate and 6g of lanthanum nitrate, adding 164mL of water and stirring to dissolve.

[0102] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis) and 6g of guar gum powder were mixed evenly for 10 min. Then, the prepared peptizing solution was added to the dry powder. The mixture was kneaded for 20 min and rolled for 50 min. The mixture was then extruded into 4 mm X-shaped strips on a screw extruder. The molding temperature was controlled at 35℃ and the molding pressure at 8.5 MPa to obtain the molded product. The temperature change of the material before and after molding was 7℃. The molded product prepared above was dried at 100℃ for 4 hours and calcined at 960℃ for 4 hours with a heating rate of 4℃ / min to obtain catalyst support A4.

[0103] Example 5

[0104] (1) Prepare the adhesive solvent solution by weighing 2.4g of 63% nitric acid, adding 6g of lanthanum nitrate as a modifier, adding 162mL of water, and stirring to dissolve.

[0105] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis), 10g of guar gum powder, 5g of modified calcium oxide, and 2g of methylcellulose were mixed evenly for 10 minutes. Then, the prepared peptone solution was added to the dry powder. The mixture was kneaded for 80 minutes until homogeneous, and then extruded into 4mm butterfly strips on a plunger extruder. The molding temperature was controlled at 45℃ and the molding pressure at 9MPa to obtain the molded product. The temperature change of the material before and after molding was 8℃. The molded product was dried at 120℃ for 4 hours and calcined at 1000℃ for 4 hours at a heating rate of 3℃ / min to obtain catalyst support A5.

[0106] Example 6

[0107] (1) Prepare the colloidal solvent solution by weighing 2.4g of 63% nitric acid, adding 6g of lanthanum nitrate, and adding 156mL of water and stirring to dissolve.

[0108] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis), 6g of guar gum powder, 7g of modified magnesium oxide, and 4g of methylcellulose were mixed evenly for 10 minutes. Then, the prepared peptizing solvent solution was added to the dry powder. The mixture was kneaded for 5 minutes, then rolled for 90 minutes to mix evenly. The mixture was then extruded into 4mm butterfly strips on a plunger extruder. The molding temperature was controlled at 40℃ and the molding pressure at 10MPa to obtain the molded product. The temperature change of the material before and after molding was 9℃. The molded product was dried at 120℃ for 4 hours and calcined at 1000℃ for 4 hours at a heating rate of 3℃ / min to obtain catalyst support A6.

[0109] Comparative Example 3

[0110] The catalyst support was prepared according to the method of Example 6, except that the mixing and rolling was carried out for 20 minutes, the molding temperature was 35°C, the temperature change before and after molding was 6°C, and the molding pressure was 3.5 MPa, thus obtaining catalyst support D3.

[0111] Comparative Example 4

[0112] The catalyst support was prepared according to the method of Example 6, except that the amount of nitric acid added was 4g, the molding temperature was 55℃, the temperature change before and after molding was 16℃, and the molding pressure was 12.5MPa, resulting in catalyst support D4. Due to the high pressure, the perforated plate was damaged, and the shape of some extruded strips was changed.

[0113] Example 7

[0114] Add 10g of water to the defective extruded strip after Comparative Example 1 and continue mixing and grinding for 40 minutes. The resulting material is shaped and dried and calcined according to the conditions of Example 1 to obtain catalyst carrier A7.

[0115] Example 8

[0116] (1) Prepare the gel solvent solution by dissolving 11.12g of aluminum nitrate in 150mL of water.

[0117] (2) 200g of pseudoboehmite powder (purchased from Sasol) was mixed with 6g of guar gum powder, 6g of magnesium oxide (a modifier), and 2g of calcium oxide (a modifier) ​​for 10 min. Then, the prepared peptizing solution was added to the dry powder. The mixture was then kneaded for 30 min and rolled for 70 min to achieve uniform mixing. The mixture was then extruded into Raschig rings with an outer diameter of 6 mm and a wall thickness of 2 mm on a plunger extruder. The molding temperature was controlled at 35℃ and the molding pressure was 5 MPa to obtain the molded product. The temperature change of the material before and after molding was 6℃. The molded product prepared above was placed at room temperature for 24 h, dried at 90℃ for 4 h, and calcined at 1000℃ for 4 h with a heating rate of 2℃ / min to obtain catalyst support A8.

[0118] Example 9

[0119] (1) Prepare the colloidal solvent solution by weighing 2.4g of 63% nitric acid and 2g of citric acid, adding 6g of lanthanum nitrate and 168mL of water, and stirring to dissolve.

[0120] (2) 200g of boehmite powder (purchased from Sasol), 6g of guar gum powder, 6g of magnesium oxide, and 2g of methylcellulose were mixed evenly for 10 min. Then, the prepared adhesive solvent solution was added to the dry powder, and the mixture was kneaded for 30 min and rolled for 90 min to mix evenly. The mixture was then extruded into 6 mm butterfly strips on a plunger extruder. The molding temperature was controlled at 30℃ and the molding pressure was 6.8 MPa to obtain the molded product. The temperature change of the material before and after molding was 6℃. The molded product was placed at room temperature for 48 h, dried at 90℃ for 4 h, and calcined at 1000℃ for 4 h with a heating rate of 2℃ / min to obtain catalyst support A9.

[0121] Example 10

[0122] (1) Prepare the colloidal solvent solution by weighing 6g of 63% nitric acid, adding 6g of lanthanum nitrate, adding 210mL of water, and stirring to dissolve.

[0123] 200g of carbonized pseudoboehmite powder (0.7% dry basis) and 6g of guar gum powder were mixed for 10 minutes. Then, the prepared peptizing solution was added to the dry powder, and the mixture was kneaded for 30 minutes and then rolled for 80 minutes to achieve uniform mixing. The resulting material was extruded into a six-toothed strip with an outer diameter of 6mm and an inner cylindrical hole of 1mm diameter on a plunger extruder. The molding temperature was controlled at 20℃ and the molding pressure at 7MPa to obtain the molded product. The temperature change of the material before and after molding was 8℃. The molded product was dried at 60℃ for 24 hours, and the dried strip was calcined at 960℃ for 4 hours at a heating rate of 2℃ / min to obtain catalyst support A10.

[0124] Example 11

[0125] (1) Prepare the colloidal solvent solution by weighing 3g citric acid, 2g lanthanum nitrate, and 2g cerium nitrate, adding 166mL water and 1.6g nitric acid with a mass concentration of 63%, and stirring to dissolve.

[0126] (2) 200g of pseudoboehmite powder (purchased from Sasol, 0.75% dry basis) and 6g of guar gum powder were dry-mixed for 10 min. Then, the prepared peptizing solvent solution was added to the dry powder, and the mixture was kneaded for 20 min and then rolled for 60 min to mix evenly. Then, Raschig rings with an outer diameter of 4 mm and a wall thickness of 1.5 mm were extruded on a plunger extruder. The molding temperature was controlled at 50℃ and the molding pressure was 8 MPa to obtain the molded product. The temperature change of the material before and after molding was 11℃. The above molded product was dried at 60℃ for 24 hours and calcined at 1050℃ for 4 hours with a heating rate of 4℃ / min to obtain catalyst support A11. Figure 3 The image shows the particle appearance of the catalyst support A11 prepared in Example 11.

[0127] Example 12

[0128] (1) Prepare the colloidal solvent solution by weighing 3g citric acid, 2g lanthanum nitrate, and 2g cerium nitrate, adding 166mL water and 1.6g nitric acid with a mass concentration of 63%, and stirring to dissolve.

[0129] (2) 200g of pseudoboehmite powder (purchased from Sasol, dry basis 0.75) and 6g of guar gum powder were dry-mixed for 10 min. Then, the prepared peptizing solvent solution was added to the dry powder. The mixture was kneaded for 20 min and then rolled for 60 min to mix evenly. Then, honeycomb strips with a diameter of 5 mm, a wall thickness of 1.8 mm, an internal through-hole wall thickness of 0.4 mm, and a through-hole spacing of 0.4 mm were extruded on a plunger extruder. The molding temperature was controlled at 50℃ and the molding pressure was 8 MPa to obtain the molded product. The temperature change of the material before and after molding was 6℃. The above molded product was dried at 60℃ for 36 hours and calcined at 1050℃ for 4 hours with a heating rate of 4℃ / min to obtain catalyst support A12.

[0130] Test case

[0131] The test results of the specific surface area, pore volume, and average mechanical strength of the prepared catalyst support are shown in Table 1. The coefficient of variation was calculated for each group of catalyst support particles, which consisted of 22 particles.

[0132] Table 1

[0133]

[0134]

[0135] As can be seen from Table 1, the catalyst supports prepared in Examples 1-12 exhibit significantly improved mechanical strength compared to Comparative Examples 1 and 2. Therefore, the method for preparing catalyst supports provided by the present invention possesses higher specific surface area and mechanical strength.

[0136] Figure 2 This is a schematic diagram of the mechanical strength distribution of the carrier in Examples 2, 6, and 3. Figure 2 As can be seen from this, the method for preparing catalyst supports provided by the present invention not only has high mechanical strength, but also low strength dispersion, which is beneficial for the catalyst to maintain stable mechanical strength in application and improve its practicality. Figure 4 The infrared spectra of the extruded strips of Example 6 and Comparative Example 3 are shown below. Figure 4 As can be seen from Example 6, the carrier precursor after molding has a larger aluminum-oxygen bond signal, indicating that the molding conditions are conducive to the formation of this bond, which is the intrinsic reason for the improved mechanical strength.

[0137] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst support, characterized in that, The specific surface area of ​​the catalyst support is 20-200 m². 2 / g, pore volume is 0.1-0.7mL / g; The average mechanical strength of the catalyst support is 18-110 N / mm; The particle mechanical strength dispersion coefficient of the catalyst support is in the range of 0-0.55; The catalyst support is selected from alumina; The particle diameter of the catalyst support is 3-20 mm; The method for preparing the catalyst support includes the following steps: The catalyst support is obtained by mixing the precursor with a peptide solvent and a modifying agent, followed by molding, drying, and calcination. Wherein, the temperature change of the material before and after molding is less than 20°C; The modifying agent is selected from at least one of compounds containing alkali metal elements, alkaline earth metal elements and rare earth metal elements. The mixing includes dry mixing, kneading and / or milling; The conditions for kneading and / or rolling include: the kneading and / or rolling time is 20-160 min; The molding conditions include: molding temperature of 5-50℃; molding pressure of 4-15MPa.

2. The catalyst support according to claim 1, wherein, The specific surface area of ​​the catalyst support is 25-190 m². 2 / g; And / or, the pore volume of the catalyst support is 0.2-0.65 mL / g.

3. The catalyst support according to claim 1, wherein, The catalyst support has an average mechanical strength of 20-100 N / mm.

4. The catalyst support according to claim 1, wherein, The particle diameter of the catalyst support is 3.5-17 mm.

5. A method for preparing a catalyst support according to any one of claims 1-4, characterized in that, The method includes the following steps: The catalyst support is obtained by mixing the precursor with a peptide solvent and a modifying agent, followed by molding, drying, and calcination. Wherein, the temperature change of the material before and after molding is less than 20°C; The modifying agent is selected from at least one of compounds containing alkali metal elements, alkaline earth metal elements and rare earth metal elements. The carrier is selected from alumina; The mixing includes dry mixing, kneading and / or milling; The conditions for kneading and / or rolling include: the kneading and / or rolling time is 20-160 min; The molding conditions include: molding temperature of 5-50℃; molding pressure of 4-15MPa.

6. The preparation method according to claim 5, wherein, The temperature change of the material before and after molding is less than 18°C.

7. The preparation method according to claim 5, wherein, The process of adding water after adding the modifying agent also includes adding water. The volume of water added is 0.5-1.5 mL, based on the weight of 1 g of the carrier precursor.

8. The preparation method according to claim 7, wherein, The process of adding water after adding the modifying agent also includes adding water. The volume of water added is 0.65-1.2 mL, based on the weight of 1 g of the carrier precursor.

9. The preparation method according to claim 5, wherein, The carrier precursor is a substance that is converted into a carrier through subsequent calcination.

10. The preparation method according to claim 9, wherein, The carrier precursor is selected from boehmite.

11. The preparation method according to claim 5, wherein, The adhesive solvent is an organic acid and / or an inorganic acid; And / or, relative to 100 parts by weight of the carrier precursor, the amount of the adhesive solvent added is 0.4-10 parts by weight.

12. The preparation method according to claim 11, wherein, The adhesive solvent is selected from at least one of nitric acid, aluminum nitrate, acetic acid, and citric acid; And / or, relative to 100 parts by weight of the carrier precursor, the amount of the adhesive solvent added is 0.4-10 parts by weight.

13. The preparation method according to claim 5, wherein, The modifying agent is selected from at least one of oxides, acetates, nitrates, hydroxides, carbonates, and basic carbonates of alkali metals, alkaline earth metals, transition metals, and rare earth metals.

14. The preparation method according to claim 13, wherein, The modifying agent is selected from at least one of lanthanum nitrate, magnesium nitrate, zinc nitrate, potassium nitrate, magnesium oxide, calcium oxide, lanthanum acetate, and magnesium acetate.

15. The preparation method according to claim 5, wherein, The amount of the modifying agent added is 0.6-15 parts by weight relative to 100 parts by weight of the carrier precursor.

16. The preparation method according to claim 15, wherein, The amount of the modifying agent added is 0.8-12 parts by weight relative to 100 parts by weight of the carrier precursor.

17. The preparation method according to claim 5, wherein, The mixture may also include optional extrusion aids, optional binders, and optional lubricants.

18. The preparation method according to claim 17, wherein, The amount of the extrusion aid added is 0-8 parts by weight relative to 100 parts by weight of the carrier precursor. And / or, relative to 100 parts by weight of the carrier precursor, the amount of the binder added is 0-4 parts by weight.

19. The preparation method according to claim 18, wherein, The amount of the extrusion aid added is 0-6 parts by weight relative to 100 parts by weight of the carrier precursor. And / or, relative to 100 parts by weight of the carrier precursor, the amount of the binder added is 0-3 parts by weight.

20. The preparation method according to claim 17, wherein, The lubricant is selected from at least one of glycerin, polyol, polyester, magnesium stearate, stearic acid, talc and graphite.

21. The preparation method according to claim 17, wherein, The amount of lubricant added is 0-10 parts by weight relative to 100 parts by weight of carrier precursor.

22. The preparation method according to claim 21, wherein, The amount of lubricant added is 0-5 parts by weight relative to 100 parts by weight of carrier precursor.

23. The preparation method according to claim 5, wherein, The molding process is selected from at least one of extrusion molding, compression molding, and ball forming.

24. The preparation method according to claim 5, wherein, The roasting conditions include: a roasting temperature of 700-1350℃; a roasting time of 1-8 hours; and a heating rate of 1-8℃ / minute.

25. The preparation method according to claim 24, wherein, The roasting conditions include: a roasting temperature of 750-1250℃; a roasting time of 2-6 hours; and a heating rate of 2-6℃ / minute.

26. The catalyst support prepared by the method according to any one of claims 5-25.

27. The application of the catalyst support according to any one of claims 1-4 and 26 in the field of catalyst preparation.

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