Supported catalyst and application thereof in preparation of isopropylamine from acetone

Abstract

The invention relates to the technical field of catalysts, in particular to a supported catalyst and application thereof in preparation of isopropylamine from acetone, the supported catalyst is a granular preparation prepared by subjecting a waste nickel-based catalyst and a waste copper-zinc catalyst to pretreatment and then subjecting the pretreated waste nickel-based catalyst and waste copper-zinc catalyst and pseudo-boehmite powder to grinding, burdening extrusion and dipping activation, the ratio of the waste nickel-based catalyst to the waste copper-zinc catalyst in the raw materials of the supported catalyst is (2-4): 1, and the waste nickel-based catalyst and the waste copper-zinc catalyst account for 40%-50% of the total mass of the supported catalyst. According to the present invention, the waste hydrogenation catalyst and the reforming catalyst are utilized to produce the supported catalyst, and the supported catalyst is applied to the preparation of the isopropylamine from the acetone, such that the stable production of the isopropylamine from the acetone is achieved, and the resource recycling is completely achieved.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a supported catalyst and application thereof in preparing isopropylamine from acetone. Background Art

[0002] A catalyst, also known as a catalyst, can change the chemical reaction rate of other substances in a chemical reaction. It is a type of substance that can change the speed of a chemical reaction without being consumed itself in the reaction.

[0003] Although they are not consumed in chemical reactions, due to their physical and chemical properties and various situations during use, catalysts are often deactivated and crushed. These catalysts can no longer be used. About 500,000 to 700,000 tons of waste catalysts are generated worldwide each year. Some manufacturers recycle catalysts containing precious metals, but the recycling value of catalysts without precious metals is not high. Therefore, many manufacturers usually purchase new catalysts while paying extra costs to find external manufacturers to handle the discarded catalysts. Therefore, how to recycle and reuse the discarded catalysts is a more prominent issue. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a supported catalyst and application thereof in preparing isopropylamine from acetone. A supported catalyst is produced by using a waste hydrogenation catalyst and a reforming catalyst, and the supported catalyst is applied to preparing isopropylamine from acetone, thereby achieving stable production of isopropylamine from acetone and fully realizing the recycling and reuse of resources.

[0005] In order to achieve the above technical effects, the technical solution used in the present invention is:

[0006] A supported catalyst is a granular preparation prepared by grinding, extruding and impregnating discarded nickel-based catalysts and discarded copper-zinc catalysts through pretreatment and together with pseudo-boehmite powder, and activating the catalysts. The ratio of discarded nickel-based catalysts to discarded copper-zinc catalysts in the raw materials of the supported catalyst is 2-4:1, and the discarded nickel-based catalysts and discarded copper-zinc catalysts account for 40%-50% of the total mass of the supported catalyst.

[0007] The present invention mainly utilizes waste catalysts, can effectively utilize existing waste catalysts for recycling and production, is suitable for catalyst manufacturers to recycle waste catalysts, reduces processing investment, and can also generate certain economic benefits.

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

[0009] Unevenly distributed active centers can improve the catalytic activity of the catalyst, reduce the occurrence of side reactions, and improve the reaction heat distribution.

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

[0011] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to obtain a pretreated nickel-based catalyst and a pretreated copper-zinc catalyst;

[0012] Step S2: Grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid and wet-milling to 200 mesh, and performing solid-liquid separation after the ball milling to obtain a filtrate and a filter residue, wherein the filtrate is used to prepare an impregnation solution;

[0013] Step S3: batching and extruding, mixing and kneading the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, and calcining to obtain a catalyst carrier;

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

[0015] The present invention utilizes existing materials to extract active ingredients and then re-makes the carrier, and then re-impregnates and activates it to obtain a new catalyst. There is no need to purchase additional materials, the method is simple, and the preparation is easy.

[0016] Furthermore, the calcination pretreatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the waste nickel-based catalyst and the waste copper-zinc catalyst in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the conversion calcination stage is to heat to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours.

[0017] In the impurity removal calcination stage, the coke in the catalyst, the impurities attached to the catalyst, and the poisoned catalyst are calcined in an aerobic environment to burn out these impurities. Then, in the conversion calcination stage, the gamma alumina on the catalyst is converted into alpha alumina to eliminate its catalytic activity and reaction performance, avoid dissolution in sulfuric acid in step S2, and reduce the impact of subsequent reuse.

[0018] Furthermore, a small amount of hydrogen peroxide is added to the filtrate obtained in step S2, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the solution is concentrated to a saturated solution at 70°C-90°C, and then the temperature of the saturated solution is raised by 5°C-10°C to obtain an impregnation solution.

[0019] The filtrate contains sulfates of active metals, which are concentrated and re-impregnated onto the carrier, allowing the active metals to return to the catalyst and form new active centers after activation.

[0020] Furthermore, during the kneading process of step S3, 2%-3% of the total weight of polyvinyl alcohol 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 is needed during the kneading process because the filtered residue contains water. Adding pseudo-boehmite powder and polyvinyl alcohol to the residue for kneading is more conducive to molding, and the polyvinyl alcohol is discharged in the subsequent calcination and shaping stage, which does not affect the attachment of the active center to the catalyst carrier.

[0022] Furthermore, in step S4, the impregnation process is as follows: placing the cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until the filtrate generated by making the batch of catalyst carriers is completely used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0023] The saturated impregnation liquid at high temperature comes into contact with the cold catalyst carrier, is absorbed by the catalyst carrier and rapidly cooled. Nickel sulfate is precipitated during the cooling process, thereby increasing the nickel content in the catalyst carrier near the surface and achieving an uneven distribution of active centers.

[0024] The supported catalyst or the preparation method is used in preparing isopropylamine from acetone. The application method is: the supported catalyst is used alone, or is used in place of quartz sand and mixed with an existing catalyst.

[0025] Beneficial Effects

[0026] 1. The present invention utilizes waste catalysts to re-prepare new catalysts, thereby reducing the problem of waste disposal and generating new benefits. The method is simple and easy to implement, fully realizing resource recovery, utilizing the effective ingredients in existing catalysts, and no additional materials need to be prepared.

[0027] 2. The present invention adjusts the distribution of active centers of the catalyst and utilizes limited active centers to achieve a higher reaction rate.

[0028] 3. The catalyst of the present invention can be used alone, or can be used in place of quartz sand and mixed with existing catalysts to make up for the deficiencies of existing catalysts, and is flexible and versatile in use. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0030] A supported catalyst is a granular preparation prepared by grinding, extruding and impregnating discarded nickel-based catalysts and discarded copper-zinc catalysts through pretreatment and together with pseudo-boehmite powder, and activating the catalysts. The ratio of discarded nickel-based catalysts to discarded copper-zinc catalysts in the raw materials of the supported catalyst is 2-4:1, and the discarded nickel-based catalysts and discarded copper-zinc catalysts 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 aldehyde and ketone hydrogenation. In terms of mass percentage, the main components of the waste catalyst include 15%-18% nickel, 0.5%-0.6% chromium, 0.18%-0.2% iron, and the rest is a carrier formed by aluminum oxide and silicon oxide.

[0032] The copper-zinc catalyst used in this embodiment is a copper-zinc catalyst for methanol synthesis. In terms of mass percentage, the main components of the waste catalyst include 20%-30% copper compounds, 20%-40% zinc compounds, about 5% insoluble matter such as carbon and trace iron, and the rest is aluminum oxide or silicon oxide.

[0033] The present invention mainly utilizes the complementary active metal types in nickel-based catalysts and copper-zinc catalysts, and utilizes the discarded catalysts. It can effectively utilize the existing discarded catalysts for production, is suitable for catalyst manufacturers to recycle the discarded catalysts, reduce processing investment, and can also generate certain economic benefits.

[0034] The nickel content in the supported catalyst gradually decreases from the surface to the inside, forming a gradient distribution. The nickel is mainly distributed in the part close to the surface of the supported catalyst, and a concentrated area of ​​nickel is formed on the catalyst surface and the part close to the surface inside the catalyst. The remaining components are distributed relatively evenly. The uneven distribution of nickel causes the active center to form a concentration gradient in the catalyst. The concentration is high near the catalyst surface, which reduces the effect of internal diffusion on the reaction rate, can improve the catalytic activity of the catalyst, make the reactants easier to adsorb, react and desorb on the catalyst, and reduce the occurrence of side reactions. At the same time, the active center close to the catalyst surface is also conducive to improving the reaction heat distribution.

[0035] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0036] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to remove organic impurities inside and improve their physical and chemical properties, thereby obtaining a pretreated nickel-based catalyst and a pretreated copper-zinc catalyst;

[0037] 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 in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the coke in the catalyst, the impurities attached to the catalyst, and the poisoned catalyst are roasted, and these impurities are burned off in an aerobic environment, and then the active metal is converted into an oxide state, which is easier for subsequent treatment; the conversion calcination stage is to heat up to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours; at a high temperature of 1200°C, the γ-alumina on the catalyst is converted into α-alumina, eliminating its catalytic activity and reaction performance, and avoiding adverse effects in subsequent treatment;

[0038] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used to prepare the impregnation solution;

[0039] A small amount of hydrogen peroxide is added to the obtained filtrate, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the filtrate is concentrated to a saturated solution with a temperature of 70°C-90°C, and then the temperature of the saturated solution is raised by 5-10°C to obtain an impregnation solution;

[0040] Step S3: batching and extrusion, mixing and kneading the filter residue obtained in step S2 with pseudo-boehmite powder, the water content in the filter residue is 15%-20%, so the mixing and kneading can be completed without adding water, extruding, roasting and shaping, and obtaining a catalyst carrier;

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

[0042] The present invention uses existing materials to extract active ingredients and then re-make the carrier, and then re-impregnate and activate it to obtain a new catalyst. There is no need to purchase additional materials, the method is simple, and the preparation is easy;

[0043] The filtrate contains sulfates of active metals. The pH is adjusted to precipitate a large amount of copper, a small amount of zinc, and elements such as iron and chromium. A large amount of copper and zinc are removed to reduce their influence on the catalytic activity of nickel. Retaining a part of zinc and copper can improve the selectivity of isopropylamine. After concentration, the impregnation solution with a higher nickel content is re-impregnated on the carrier to make the active metal return to the catalyst and form new active centers after activation.

[0044] In the step S3, 2% to 3% of the total weight of polyvinyl alcohol is added as a binder during the kneading process; the polyvinyl alcohol is discharged during the subsequent calcination and shaping stage, and does not affect the attachment of the active center to 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: placing the cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until the filtrate generated by making the catalyst carrier is completely used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0047] The above-mentioned spraying uses an ordinary spray nozzle, and the droplets are larger than the particle size of the atomizing nozzle to avoid the atomization effect that causes the impregnation liquid to dry. After the droplets of the impregnation liquid at high temperature come into contact with the cold catalyst, they are absorbed by the catalyst and quickly cooled down. Nickel is precipitated in the cooling process, thereby increasing the nickel content in the part close to the surface of the catalyst carrier, thereby achieving an uneven distribution of active centers.

[0048] Embodiment 1:

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

[0050] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0051] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to obtain a pretreated nickel-based catalyst and a 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 in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the conversion calcination stage is to heat to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours;

[0053] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used to prepare the impregnation solution;

[0054] A small amount of hydrogen peroxide is added to the obtained filtrate, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the filtrate is concentrated to a saturated solution with a temperature of 70°C-90°C, and then the temperature of the saturated solution is raised by 5-10°C to obtain an impregnation solution;

[0055] Step S3: batching and extruding, mixing the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, roasting and shaping, to obtain a catalyst carrier;

[0056] Step S4: impregnation and activation, the catalyst carrier obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain a supported catalyst;

[0057] The impregnation process is as follows: placing a cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until all the filtrate generated by making the catalyst carrier is used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0058] After testing, the specific surface area of ​​the supported catalyst is 170m2 / g and the pore volume is 0.3ml / g.

[0059] The nickel content in the supported catalyst is 7.2%, and is concentrated in the area close to the surface of the catalyst carrier. A certain amount of copper and zinc are planted on the catalyst carrier.

[0060] Embodiment 2:

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

[0062] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0063] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to obtain a pretreated nickel-based catalyst and a 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 in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the conversion calcination stage is to heat to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours;

[0065] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used to prepare the impregnation solution;

[0066] A small amount of hydrogen peroxide is added to the obtained filtrate, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the filtrate is concentrated to a saturated solution with a temperature of 70°C-90°C, and then the temperature of the saturated solution is raised by 5-10°C to obtain an impregnation solution;

[0067] Step S3: batching and extrusion, mixing and kneading the filter residue obtained in step S2 with pseudo-boehmite powder, the water content in the filter residue is 15%-20%, so the mixing and kneading can be completed without adding water, extruding, roasting and shaping, and obtaining a catalyst carrier;

[0068] Step S4: impregnation and activation, the catalyst carrier obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain a supported catalyst;

[0069] The impregnation process is as follows: placing a cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until all the filtrate generated by making the catalyst carrier is used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0070] After testing, the specific surface area of ​​the supported catalyst is 200m2 / g; the pore volume is 0.47ml / g.

[0071] The nickel content in the supported catalyst is 5.4%, and is concentrated in the area close to the surface of the catalyst carrier. A certain amount of copper and zinc are planted on the catalyst carrier.

[0072] Embodiment three:

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

[0074] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0075] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to obtain a pretreated nickel-based catalyst and a 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 in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the conversion calcination stage is to heat to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours;

[0077] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used to prepare the impregnation solution;

[0078] A small amount of hydrogen peroxide is added to the obtained filtrate, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the filtrate is concentrated to a saturated solution with a temperature of 70°C-90°C, and then the temperature of the saturated solution is raised by 5-10°C to obtain an impregnation solution;

[0079] Step S3: batching and extruding, mixing the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, roasting and shaping, to obtain a catalyst carrier;

[0080] Step S4: impregnation and activation, the catalyst carrier obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain a supported catalyst;

[0081] The impregnation process is as follows: placing a cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until all the filtrate generated by making the catalyst carrier is used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0082] After testing, the specific surface area of ​​the supported catalyst is 190m2 / g and the pore volume is 0.4ml / g.

[0083] The nickel content in the supported catalyst is 7.2%, and is concentrated in the area close to the surface of the catalyst carrier. A certain amount of copper and zinc are planted on the catalyst carrier.

[0084] Comparative Example 1:

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

[0086] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0087] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then calcining them at 500° C. to obtain a pretreated nickel-based catalyst and a pretreated copper-zinc catalyst;

[0088] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used for impregnation;

[0089] Step S3: batching and extruding, mixing the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, roasting and shaping, to obtain a catalyst carrier;

[0090] Step S4: impregnation and activation, the catalyst carrier obtained in step S3 is impregnated and activated with the filtrate obtained in step S2 to obtain a supported catalyst;

[0091] The impregnation process is as follows: placing a cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until all the filtrate generated by making the catalyst carrier is used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

[0092] After testing, the specific surface area of ​​the supported catalyst is 240m2 / g and the pore volume is 0.5ml / g.

[0093] The nickel content in the supported catalyst is 7%, and is concentrated in the area close to the surface of the catalyst carrier. A large amount of copper and zinc are planted on the catalyst carrier.

[0094] Comparative Example 2:

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

[0096] The method for preparing the above-mentioned supported catalyst comprises the following steps:

[0097] Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then calcining them at 500° C. to obtain a pretreated nickel-based catalyst and a pretreated copper-zinc catalyst;

[0098] Step S2: grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid with a concentration of 1 mol / L and wet-milling to 200 mesh, the ratio of material, ball and solvent is 1:2:1; the grinding balls are high-purity alumina grinding balls, and the ratio of large balls, medium balls and small balls is 3:20:77; the ball milling time is 3h-5h, and after the ball milling is completed, suction filtration or filter press is used for solid-liquid separation to obtain filtrate and filter residue, wherein the filtrate is used for impregnation;

[0099] Step S3: batching and extruding, mixing the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, roasting and shaping, to obtain a catalyst carrier;

[0100] Step S4: impregnation and activation, the catalyst carrier obtained in step S3 is impregnated and activated with the filtrate obtained in step S2 to obtain a supported catalyst;

[0101] The impregnation process is to use the filtrate to perform equal volume impregnation.

[0102] After testing, the specific surface area of ​​the supported catalyst is 240m2 / g and the pore volume is 0.5ml / g.

[0103] The content of nickel in the supported catalyst is 7%, which is evenly distributed on the catalyst carrier, and a large amount of copper and zinc are planted on the catalyst carrier.

[0104] The method for detecting the nickel content in the catalyst is SH / T 0346-1992 Determination of nickel content in hydrorefining catalysts

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

[0106] The supported catalyst and the method for preparing the supported catalyst are used in preparing isopropylamine from acetone. The application method is: the supported catalyst is used alone, or is used in place of quartz sand and mixed with an existing catalyst.

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

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

[0109] When the above-mentioned supported catalyst is used in place of quartz sand and mixed with the existing catalyst, the ratio of the above-mentioned supported catalyst to the existing catalyst is 1:1, the ratio of the filling height to the reactor diameter is 9-10, and after filling, the air is replaced by nitrogen and then activated with hydrogen at 300°C for 6 hours, and then slowly cooled to 120°C, the pressure in the reactor is 0.4MPa, the inlet molar ratio of acetone, ammonia and hydrogen is 1:3:4, and the air velocity is 0.5h -1 At this time, 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 only used to explain the present invention, and are not used to limit the present invention.

Claims

1. A supported catalyst, characterized in that The supported catalyst is a granular preparation prepared by grinding, extruding and impregnating discarded nickel-based catalysts and discarded copper-zinc catalysts with pseudo-boehmite powder after pretreatment. The ratio of discarded nickel-based catalysts to discarded copper-zinc catalysts in the raw materials of the supported catalyst is 2-4:1, and the discarded nickel-based catalysts and discarded copper-zinc catalysts account for 40%-50% of the total mass of the supported catalyst.

2. The supported catalyst according to claim 1, characterized in that The nickel content in the supported catalyst gradually decreases from the surface to the inside, forming a gradient distribution.

3. A method for preparing the supported catalyst according to claim 1 or 2, characterized in that: The following steps are involved: Step S1: pretreatment, mixing the waste nickel-based catalyst and the waste copper-zinc catalyst and then performing calcination pretreatment to obtain a pretreated nickel-based catalyst and a pretreated copper-zinc catalyst; Step S2: Grinding, adding the pretreated nickel-based catalyst and the pretreated copper-zinc catalyst obtained in step S1 into a ball mill, adding sulfuric acid and wet-milling to 200 mesh, and performing solid-liquid separation after the ball milling to obtain a filtrate and a filter residue, wherein the filtrate is used to prepare an impregnation solution; Step S3: batching and extruding, mixing and kneading the filter residue obtained in step S2 with pseudo-boehmite powder, extruding, and calcining to obtain a catalyst carrier; Step S4: impregnation and activation. The catalyst carrier obtained in step S3 is impregnated and activated using the impregnation solution prepared from the filtrate obtained in step S2 to obtain a supported catalyst.

4. The preparation method according to claim 3, characterized in that: The calcination pretreatment in step S1 includes two stages: impurity removal calcination and conversion calcination. In the impurity removal calcination stage, the waste nickel-based catalyst and the waste copper-zinc catalyst in step S1 are placed in a calcination container, heated to 500°C at 30-50°C / min, and kept warm for 1-2 hours; the conversion calcination stage is to heat to 1200°C at 5-10°C / min after the impurity removal calcination stage is finished, and kept warm for 1-2 hours.

5. The preparation method according to claim 3, characterized in that: A small amount of hydrogen peroxide is added to the filtrate obtained in step S2, and then the pH is adjusted to 5-5.5 with ammonia water, the precipitate is filtered to remove, and the solution is concentrated to a saturated solution at 70° C.-90° C., and then the temperature of the saturated solution is raised by 5° C.-10° C. to obtain an impregnation solution.

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

7. The preparation method according to claim 3, characterized in that: In step S4, the impregnation process is as follows: placing the cooled catalyst carrier in a rotating container, spraying the impregnation liquid on the surface of the catalyst carrier until the filtrate generated by making the batch of catalyst carriers is completely used up, and drying the catalyst carrier adsorbed with the impregnation liquid.

8. Use of the supported catalyst according to any one of claims 1 to 2 or the preparation method according to any one of claims 3 to 7 in preparing isopropylamine from acetone.