A supported catalyst and its application in the preparation of isopropylamine from acetone.

Abstract

This invention relates to the field of catalyst technology, specifically to a supported catalyst and its application in the production of isopropylamine from acetone. The supported catalyst is a granular formulation prepared by pretreatment of waste nickel-based catalysts and waste copper-zinc catalysts, followed by grinding, batching, extrusion, and impregnation activation with boehmite powder. The ratio of waste nickel-based catalyst to waste copper-zinc catalyst in the raw materials of the supported catalyst is 2-4:1, and the waste nickel-based catalyst and waste copper-zinc catalyst account for 40%-50% of the total mass of the supported catalyst. This invention utilizes waste hydrogenation catalysts and reforming catalysts to produce a supported catalyst, and applies it to the production of isopropylamine from acetone, achieving stable production of isopropylamine from acetone and fully realizing resource recycling and reuse.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a supported catalyst and its application in the preparation of isopropylamine from acetone. Background Technology

[0002] Catalysts, also known as catalysts, are substances that can change the rate of chemical reactions of other substances. They are substances that can change the rate of chemical reactions without being consumed in the reaction itself.

[0003] Although catalysts are not consumed in chemical reactions, they often become deactivated or pulverized due to their physical and chemical properties and various conditions during use. These catalysts are no longer usable. Globally, approximately 500,000 to 700,000 tons of waste catalysts are generated annually. Some manufacturers recycle catalysts containing precious metals, but catalysts without precious metals have low recycling value. Therefore, many manufacturers often have to pay extra to find external manufacturers to dispose of waste catalysts while purchasing new ones. Thus, how to recycle and reuse waste catalysts is a prominent issue. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a supported catalyst and its application in the preparation of isopropylamine from acetone. A supported catalyst is produced using waste hydrogenation catalyst and reforming catalyst, and then applied to the preparation of isopropylamine from acetone, achieving stable production of isopropylamine from acetone and fully realizing resource recycling and reuse.

[0005] To achieve the above-mentioned technical effects, the technical solution used in this invention is as follows:

[0006] A supported catalyst is a granular formulation prepared by pretreatment of waste nickel-based catalyst and waste copper-zinc catalyst, followed by grinding, batching, extrusion, and impregnation activation with boehmite powder. The ratio of waste nickel-based catalyst to waste copper-zinc catalyst in the raw materials of the supported catalyst is 2-4:1, and the waste nickel-based catalyst and waste copper-zinc catalyst account for 40%-50% of the total mass of the supported catalyst.

[0007] This invention mainly utilizes waste catalysts, effectively recycling and producing from existing waste catalysts. It is suitable for catalyst manufacturers to recycle and reuse waste catalysts, reducing processing costs and generating certain economic benefits.

[0008] Furthermore, the nickel content in the supported catalyst gradually decreases from the surface to the interior, forming a gradient distribution.

[0009] Non-uniformly distributed active centers can improve the catalytic activity of catalysts, reduce the occurrence of side reactions, and improve the heat distribution of the reaction.

[0010] A method for preparing the above-mentioned supported catalyst includes the following steps:

[0011] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted for pretreatment to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0012] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill and wet-milled to 200 mesh with sulfuric acid. After ball milling, solid-liquid separation is performed to obtain filtrate and filter residue. The filtrate is used to prepare impregnation solution.

[0013] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, and calcined to obtain the catalyst support.

[0014] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst.

[0015] This invention utilizes existing materials to extract active ingredients, then re-fabricates the carrier, and subsequently impregnates and activates it to obtain a new catalyst. No additional materials are required, and the method is simple and easy to manufacture.

[0016] Furthermore, the roasting pretreatment in step S1 includes two stages: impurity removal roasting and conversion roasting. In the impurity removal roasting stage, the waste nickel-based catalyst and waste copper-zinc catalyst from step S1 are placed in a roasting container and heated to 500°C at a rate of 30-50°C / min, and held at that temperature for 1-2 hours. In the conversion roasting stage, after the heat treatment in the impurity removal roasting stage is completed, the temperature is increased to 1200°C at a rate of 5-10°C / min, and held at that temperature for 1-2 hours.

[0017] The impurity removal roasting stage roasts coke, impurities attached to the catalyst, and poisoned catalyst in an aerobic environment to remove these impurities. Then, the conversion roasting stage converts the γ-alumina on the catalyst into α-alumina, eliminating its catalytic activity and reaction performance, avoiding dissolution in sulfuric acid in step S2, and reducing the impact of subsequent reuse.

[0018] Further, in step S2, a small amount of hydrogen peroxide is added to the filtrate, and then the pH is adjusted to 5-5.5 using ammonia. The precipitate is removed by filtration, and the solution is concentrated to a saturated solution at 70℃-90℃. Then, the temperature of the saturated solution is increased by 5℃-10℃ to obtain the impregnation solution.

[0019] The filtrate contains sulfates of active metals. After concentration, it is re-impregnated onto the support, allowing the active metals to return to the catalyst and form new active centers after activation.

[0020] Furthermore, in the mixing process of step S3, 2%-3% of polyvinyl alcohol by weight of the total ingredients is added as a binder; in step S3, the extruded carrier is a columnar body with a diameter of 2 mm and a length of 3 mm-5 mm.

[0021] No additional water needs to be added during the kneading process because the filter residue contains water. Adding boehmite powder and polyvinyl alcohol to the filter residue for kneading is more conducive to molding. Furthermore, the polyvinyl alcohol is discharged during the subsequent calcination and shaping stage, which does not affect the adhesion of the active centers on the catalyst carrier.

[0022] Further, in step S4, the impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of this batch of catalyst supports is used up, and the catalyst support adsorbed with impregnation liquid is dried.

[0023] When the saturated impregnation solution at high temperature comes into contact with the cool catalyst support, it is absorbed by the catalyst support and rapidly cooled. During the cooling process, nickel sulfate is precipitated, which increases the nickel content in the part of the catalyst support near the surface, resulting in an uneven distribution of active centers.

[0024] The application of the above-mentioned supported catalyst or the above-mentioned preparation method in the preparation of isopropylamine from acetone; the application method is: the above-mentioned supported catalyst is used alone, or it is used in place of quartz sand and mixed with existing catalysts.

[0025] Beneficial effects

[0026] 1. This invention utilizes waste catalysts to regenerate new catalysts, reducing waste disposal problems and generating new benefits. The method is simple and easy to implement, fully realizing resource recovery and utilizing the effective components in existing catalysts without the need for additional material preparation.

[0027] 2. This invention adjusts the distribution of active sites in the catalyst, achieving a larger reaction rate by utilizing a limited number of active sites.

[0028] 3. The catalyst of the present invention can be used alone or mixed with existing catalysts to replace quartz sand, making up for the shortcomings of existing catalysts and making it flexible in use. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0030] A supported catalyst is a granular formulation prepared by pretreatment of waste nickel-based catalyst and waste copper-zinc catalyst, followed by grinding, batching, extrusion, and impregnation activation with boehmite powder. The ratio of waste nickel-based catalyst to waste copper-zinc catalyst in the raw materials of the supported catalyst is 2-4:1, and the waste nickel-based catalyst and waste copper-zinc catalyst account for 40%-50% of the total mass of the supported catalyst.

[0031] The nickel-based catalyst used in this embodiment is a nickel-based catalyst for the hydrogenation of aldehydes and ketones. By mass percentage, the main components of its spent catalyst include 15%-18% nickel, 0.5%-0.6% chromium, 0.18%-0.2% iron, and the remainder is a support formed by alumina and silicon oxide.

[0032] The copper-zinc catalyst used in this embodiment is a copper-zinc catalyst for methanol synthesis. By mass percentage, the main components of its spent catalyst include 20%-30% copper compounds, 20%-40% zinc compounds, about 5% carbon and other insoluble substances, and trace amounts of iron, with the remainder being alumina or silicon dioxide.

[0033] This invention mainly utilizes the complementary active metals in nickel-based catalysts and copper-zinc catalysts to make use of waste catalysts. It can effectively utilize existing waste catalysts for production, making it suitable for catalyst users to recycle waste catalysts, reduce processing costs, and generate certain economic benefits.

[0034] In the supported catalyst, the nickel content gradually decreases from the surface to the interior, forming a gradient distribution. Nickel is mainly distributed near the surface of the supported catalyst, and concentrated areas of nickel are formed on the catalyst surface and in the interior of the catalyst near the surface. The remaining components are distributed relatively uniformly. The non-uniform distribution of nickel creates a concentration gradient of active centers in the catalyst, with a higher concentration near the catalyst surface. This reduces the influence of internal diffusion on the reaction rate, improves the catalytic activity of the catalyst, and makes it easier for reactants to be adsorbed, reacted, and desorbed on the catalyst, reducing the occurrence of side reactions. At the same time, the proximity of active centers to the catalyst surface also helps to improve the heat distribution of the reaction.

[0035] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0036] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted to remove internal organic impurities and improve their physicochemical properties, so as to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0037] The pre-calcination treatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the nickel-based catalyst and copper-zinc catalyst from step S1 are placed in a calcination vessel and heated to 500℃ at a rate of 30-50℃ / min, and held at this temperature for 1-2 hours. This calcination removes coke, impurities attached to the catalyst, and poisoned catalyst in an aerobic environment, converting the active metal into an oxide state, making it easier for subsequent processing. In the conversion calcination stage, after the impurity removal calcination stage, the temperature is increased to 1200℃ at a rate of 5-10℃ / min and held for 1-2 hours. At this high temperature of 1200℃, the γ-alumina on the catalyst is converted to α-alumina, eliminating its catalytic activity and reactivity, and preventing adverse effects in subsequent processing.

[0038] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used to prepare the impregnation solution.

[0039] A small amount of hydrogen peroxide was added to the obtained filtrate, and then the pH was adjusted to 5-5.5 with ammonia. The precipitate was removed by filtration and the solution was concentrated to a saturated solution at a temperature of 70℃-90℃. Then the temperature of the saturated solution was raised by 5-10℃ to obtain the impregnation solution.

[0040] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder. The water content in the filter residue is 15%-20%, so no water needs to be added to complete the mixing. The mixture is then extruded, calcined and shaped to obtain the catalyst carrier.

[0041] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst.

[0042] This invention utilizes existing materials to extract active ingredients, then re-fabricates the carrier, and subsequently re-impregnates and activates it to obtain a new catalyst. No additional materials are required, and the method is simple and easy to manufacture.

[0043] The filtrate contains sulfates of active metals. Adjusting the pH precipitates a large amount of copper, a small amount of zinc, and elements such as iron and chromium. Removing a large amount of copper and zinc reduces their impact on the catalytic activity of nickel. Retaining some zinc and copper can improve the selectivity of isopropylamine. After concentration, the impregnation solution with a higher nickel content is re-impregnated onto the support, allowing the active metal to return to the catalyst and form new active centers after activation.

[0044] In step S3, 2%-3% of the total weight of polyvinyl alcohol is added as a binder during the kneading process; the polyvinyl alcohol is discharged in the subsequent calcination and shaping stage, without affecting the adhesion of the active centers on the carrier.

[0045] In step S3, the extruded carrier is a columnar body with a diameter of 2 mm and a length of 3 mm to 5 mm.

[0046] In step S4, the impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of the catalyst support is used up, and the catalyst support adsorbed with the impregnation liquid is dried.

[0047] The above-mentioned spraying uses ordinary spray nozzles, and the droplets are larger than those of atomizing nozzles to avoid atomization and drying of the impregnation liquid. When the droplets of the impregnation liquid come into contact with the cool catalyst at high temperature, they are absorbed by the catalyst and rapidly cooled down. During the cooling process, nickel is precipitated, thereby increasing the nickel content in the part of the catalyst support near the surface and achieving uneven distribution of active centers.

[0048] Example 1:

[0049] The raw materials for the supported catalyst include 45% boehmite powder, 40% nickel-based catalyst, and 15% copper-zinc catalyst.

[0050] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0051] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted for pretreatment to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0052] The calcination pretreatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the nickel-based catalyst and the copper-zinc catalyst from step S1 are placed in a calcination container and heated to 500°C at a rate of 30-50°C / min, and held at that temperature for 1-2 hours. In the conversion calcination stage, after the impurity removal calcination stage is completed, the temperature is increased to 1200°C at a rate of 5-10°C / min, and held at that temperature for 1-2 hours.

[0053] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used to prepare the impregnation solution.

[0054] A small amount of hydrogen peroxide was added to the obtained filtrate, and then the pH was adjusted to 5-5.5 with ammonia. The precipitate was removed by filtration and the solution was concentrated to a saturated solution at a temperature of 70℃-90℃. Then the temperature of the saturated solution was raised by 5-10℃ to obtain the impregnation solution.

[0055] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, calcined and shaped to obtain the catalyst support.

[0056] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst.

[0057] The impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of the catalyst support is used up. The catalyst support with the impregnation liquid adsorbed is then dried.

[0058] The supported catalyst was tested and found to have a specific surface area of ​​170 m² / g and a pore volume of 0.3 ml / g.

[0059] In the supported catalyst, the nickel content is 7.2%, and it is concentrated in the region near the surface of the catalyst support. Copper and zinc are also embedded on the catalyst support.

[0060] Example 2:

[0061] The raw materials for the supported catalyst include 60% boehmite powder, 30% nickel-based catalyst, and 10% copper-zinc catalyst.

[0062] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0063] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted for pretreatment to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0064] The calcination pretreatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the nickel-based catalyst and the copper-zinc catalyst from step S1 are placed in a calcination container and heated to 500°C at a rate of 30-50°C / min, and held at that temperature for 1-2 hours. In the conversion calcination stage, after the impurity removal calcination stage is completed, the temperature is increased to 1200°C at a rate of 5-10°C / min, and held at that temperature for 1-2 hours.

[0065] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used to prepare the impregnation solution.

[0066] A small amount of hydrogen peroxide was added to the obtained filtrate, and then the pH was adjusted to 5-5.5 with ammonia. The precipitate was removed by filtration and the solution was concentrated to a saturated solution at a temperature of 70℃-90℃. Then the temperature of the saturated solution was raised by 5-10℃ to obtain the impregnation solution.

[0067] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder. The water content in the filter residue is 15%-20%, so no water needs to be added to complete the mixing. The mixture is then extruded, calcined and shaped to obtain the catalyst carrier.

[0068] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst.

[0069] The impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of the catalyst support is used up. The catalyst support with the impregnation liquid adsorbed is then dried.

[0070] The supported catalyst was tested and found to have a specific surface area of ​​200 m² / g and a pore volume of 0.47 ml / g.

[0071] In the supported catalyst, the nickel content is 5.4%, and it is concentrated in the region near the surface of the catalyst support. Copper and zinc are also embedded on the catalyst support.

[0072] Example 3:

[0073] The raw materials for the supported catalyst include 50% boehmite powder, 40% nickel-based catalyst, and 10% copper-zinc catalyst.

[0074] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0075] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted for pretreatment to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0076] The calcination pretreatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the nickel-based catalyst and the copper-zinc catalyst from step S1 are placed in a calcination container and heated to 500°C at a rate of 30-50°C / min, and held at that temperature for 1-2 hours. In the conversion calcination stage, after the impurity removal calcination stage is completed, the temperature is increased to 1200°C at a rate of 5-10°C / min, and held at that temperature for 1-2 hours.

[0077] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used to prepare the impregnation solution.

[0078] A small amount of hydrogen peroxide was added to the obtained filtrate, and then the pH was adjusted to 5-5.5 with ammonia. The precipitate was removed by filtration and the solution was concentrated to a saturated solution at a temperature of 70℃-90℃. Then the temperature of the saturated solution was raised by 5-10℃ to obtain the impregnation solution.

[0079] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, calcined and shaped to obtain the catalyst support.

[0080] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst.

[0081] The impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of the catalyst support is used up. The catalyst support with the impregnation liquid adsorbed is then dried.

[0082] The supported catalyst was tested and found to have a specific surface area of ​​190 m² / g and a pore volume of 0.4 ml / g.

[0083] In the supported catalyst, the nickel content is 7.2%, and it is concentrated in the region near the surface of the catalyst support. Copper and zinc are also embedded on the catalyst support.

[0084] Comparative Example 1:

[0085] The raw materials for the supported catalyst include 50% boehmite powder, 40% nickel-based catalyst, and 10% copper-zinc catalyst.

[0086] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0087] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then calcined at 500℃ to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0088] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used for impregnation.

[0089] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, calcined and shaped to obtain the catalyst support.

[0090] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the filtrate obtained in step S2 to obtain the supported catalyst.

[0091] The impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of the catalyst support is used up. The catalyst support with the impregnation liquid adsorbed is then dried.

[0092] The supported catalyst was tested and found to have a specific surface area of ​​240 m² / g and a pore volume of 0.5 ml / g.

[0093] In the supported catalyst, the nickel content is 7%, and it is concentrated in the region near the surface of the catalyst support. A large amount of copper and zinc are colonized on the catalyst support.

[0094] Comparative Example 2:

[0095] The raw materials for the supported catalyst include 50% boehmite powder, 40% nickel-based catalyst, and 10% copper-zinc catalyst.

[0096] The preparation method of the above-mentioned supported catalyst includes the following steps:

[0097] Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then calcined at 500℃ to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst.

[0098] Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill. 1 mol / L sulfuric acid is added and the mixture is wet-milled to 200 mesh. The ratio of material, balls, and solvent is 1:2:1. The grinding balls are high-purity alumina grinding balls, and the ratio of large, medium, and small balls is 3:20:77. The ball milling time is 3-5 hours. After ball milling, solid-liquid separation is performed using vacuum filtration or pressure filtration to obtain filtrate and filter residue. The filtrate is used for impregnation.

[0099] Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, calcined and shaped to obtain the catalyst support.

[0100] Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the filtrate obtained in step S2 to obtain the supported catalyst.

[0101] The impregnation process involves impregnating an equal volume of filtrate.

[0102] The supported catalyst was tested and found to have a specific surface area of ​​240 m² / g and a pore volume of 0.5 ml / g.

[0103] In the supported catalyst, the nickel content is 7%, which is uniformly distributed on the catalyst support, and a large amount of copper and zinc are colonized on the catalyst support.

[0104] The method for determining the nickel content in the catalyst is SH / T 0346-1992, "Determination of Nickel Content in Hydrorefining Catalysts".

[0105] The specific surface area and pore size of the catalyst were analyzed using the ASAP2020 fully automated rapid specific surface area and mesopore microanalyzer.

[0106] The above-mentioned supported catalyst and its preparation method are applied in the preparation of isopropylamine from acetone. The application method is as follows: the above-mentioned supported catalyst is used alone or mixed with existing catalysts to replace quartz sand.

[0107] Taking the supported catalyst produced in Example 3 as an example:

[0108] When the above-mentioned supported catalyst is used alone, the ratio of the catalyst packing height to the reactor diameter is 9-10. After packing, the air is replaced with nitrogen, followed by activation with hydrogen at 300℃ for 6 hours, and then the temperature is slowly reduced to 120℃. The reactor pressure is 0.8 MPa, the inlet molar ratio of acetone, ammonia, and hydrogen is 1:3:4, and the space velocity is 0.3 h⁻¹. -1 At this point, the acetone conversion rate was 94.2%, and the isopropylamine selectivity was 96.56%.

[0109] When the above-mentioned supported catalyst replaces quartz sand and is blended with existing catalysts, the ratio of the supported catalyst to the existing catalyst is 1:1, the ratio of packing height to reactor diameter is 9-10, after packing, the air is replaced with nitrogen and then activated with hydrogen at 300℃ for 6 hours, followed by slow cooling to 120℃. The pressure inside the reactor is 0.4MPa, the inlet molar ratio of acetone, ammonia, and hydrogen is 1:3:4, and the space velocity is 0.5h⁻¹. -1 At this point, the acetone conversion rate was 98.7%, and the isopropylamine selectivity was 97.22%.

[0110] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Claims

1. A method for preparing a supported catalyst, characterized in that, Includes the following steps: Step S1: Pretreatment, the waste nickel-based catalyst and the waste copper-zinc catalyst are mixed and then roasted for pretreatment to obtain the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst. Step S2: Grinding. The pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 are added to a ball mill and wet-milled to 200 mesh with sulfuric acid. After ball milling, solid-liquid separation is performed to obtain filtrate and filter residue. The filtrate is used to prepare impregnation solution. Step S3: Batching and extrusion. The filter residue obtained in step S2 is mixed with boehmite powder, extruded, and calcined to obtain the catalyst support. Step S4: Impregnation and activation. The catalyst support obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain the supported catalyst. The roasting pretreatment in step S1 includes two stages: impurity removal roasting and conversion roasting. In the impurity removal roasting stage, the waste nickel-based catalyst and waste copper-zinc catalyst from step S1 are placed in a roasting container and heated to 500°C at 30-50°C / min, and kept at that temperature for 1-2 hours. The conversion roasting stage is to raise the temperature to 1200℃ at a rate of 5-10℃ / min and hold it for 1-2 hours after the heat preservation stage of impurity removal roasting. In step S2, a small amount of hydrogen peroxide is added to the filtrate, and then the pH is adjusted to 5-5.5 using ammonia. The precipitate is removed by filtration and the solution is concentrated to a saturated solution at 70℃-90℃. Then, the temperature of the saturated solution is increased by 5℃-10℃ to obtain the impregnation solution. The spent nickel-based catalyst is a nickel-based catalyst for the hydrogenation of aldehydes and ketones. By mass percentage, the main components of the spent catalyst include 15%-18% nickel, 0.5%-0.6% chromium, 0.18%-0.2% iron, and the remainder is a support formed by alumina and silicon oxide. The spent copper-zinc catalyst is a copper-zinc catalyst used for methanol synthesis. By mass percentage, the main components of the spent catalyst include 20%-30% copper compounds, 20%-40% zinc compounds, 5% carbon-containing insoluble matter and trace amounts of iron, with the remainder being alumina or silicon dioxide.

2. The preparation method according to claim 1, characterized in that, In step S3, 2%-3% of the total weight of polyvinyl alcohol is added as a binder during the kneading process; in step S3, the extruded carrier is a columnar body with a diameter of 2mm and a length of 3mm-5mm.

3. The preparation method according to claim 1, characterized in that, In step S4, the impregnation process is as follows: the cooled catalyst support is placed in a rotating container, and the impregnation liquid is sprayed onto the surface of the catalyst support until all the filtrate produced in the production of this batch of catalyst supports is used up, and the catalyst support adsorbed with the impregnation liquid is dried.

4. A supported catalyst, characterized in that, It is prepared by the method described in any one of claims 1-3.

5. The supported catalyst according to claim 4, characterized in that, The ratio of waste nickel-based catalyst to waste copper-zinc catalyst in the raw materials of the supported catalyst is 2-4:1, and the waste nickel-based catalyst and waste copper-zinc catalyst account for 40%-50% of the total mass of the supported catalyst.

6. The supported catalyst according to claim 4, characterized in that, The nickel content in the supported catalyst gradually decreases from the surface to the interior, forming a gradient distribution.

7. The application of the supported catalyst prepared by any one of claims 1-3 in the preparation of isopropylamine from acetone.