A method for resource utilization of waste alumina-supported hydrogenation catalyst

Abstract

The present invention discloses a resource utilization method for recycling aluminum oxide from a waste alumina carrier hydrogenation catalyst, the method comprising the following steps: (1) after pretreatment of the waste alumina carrier hydrogenation catalyst, a composite alkali leaching agent is used to leach the loaded metal component A, solid-liquid separation, and the obtained aluminum-containing residue is roasted to obtain a γ-Al2O3 carrier; (2) the γ-Al2O3 carrier obtained in step (1) is impregnated with the loaded metal component B to obtain a catalyst precursor; (3) the catalyst precursor obtained in step (2) is dried, roasted, and reduced to obtain a finished catalyst. The method provided by the present invention can efficiently and low-costly purify the aluminum oxide in the waste alumina carrier, directly utilize the leached aluminum-containing residue to prepare a new catalyst, avoid the complex process of Al in the purification and recovery process, save processing costs, improve economic benefits, and have important industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of waste catalyst recovery, and more particularly to a method for resource utilization of waste alumina-supported hydrogenation catalysts. Background Art

[0002] With increasingly stringent environmental protection requirements, one of the key future development directions for oil refining is inevitably to improve the ability to produce clean fuels. Hydrogenation technology is a key measure to achieve this goal. Hydrogenation catalysts, typically composed of a carrier activated alumina and a metal active component, are in high demand each year, but their service life is generally short, approximately 1-4 years. Consequently, a large amount of discarded hydrogenation catalysts is generated annually.

[0003] Currently, the most commonly used hazardous waste treatment methods in industry include solidification landfill and metal recovery. If landfill is used, current landfill sites have high requirements for the disposal of spent catalysts, limited land resources, high transportation and disposal costs, and do not fundamentally solve the pollution problem of spent catalysts.

[0004] Waste hydrogenation catalysts, in addition to the alumina carrier, also contain metals such as molybdenum, vanadium, cobalt, and nickel, which have high economic value. Currently, most recovery technologies focus on recovering metals, using dry and wet methods. Since waste alumina-supported hydrogenation catalysts are secondary resources with complex composition and high impurity content, wet recovery methods are more suitable. CN202011188350.7 discloses a method for recycling spent hydrogenation catalysts. The method involves six steps: oxidative roasting, leaching, recovery of vanadium, recovery of molybdic acid, recovery of nickel, and recovery of aluminum. The resulting products are ammonium metavanadate, molybdic acid, phosphosilicate slag, ammonium molybdate filter residue, nickel-rich slag, and aluminum hydroxide. CN202110726100.2 discloses a method for extracting vanadium, molybdenum and nickel from waste hydrodesulfurization aluminum-based petroleum catalysts. Under normal pressure, oxidizing gas is aerated into a reaction slurry composed of a mixture of waste catalysts, ammonium sulfate solution and additives, thereby achieving simultaneous and efficient leaching of vanadium, molybdenum and nickel, and obtaining an ammonium sulfate leachate containing vanadium, molybdenum and nickel and aluminum-containing tailings.

[0005] At present, after the metal recovery of waste alumina-supported hydrogenation catalysts, the aluminum-containing residue is not properly handled. According to the solid waste identification standard (GB 34330-2017), the aluminum-containing residue is difficult to meet the requirements of standards such as alumina (GB / T 24487-2009) and aluminum hydroxide (GB / T 4294-2010). It still contains a large amount of impurities, and the purification cost is high, making it difficult to sell as a product. Waste alumina-supported catalysts usually contain 50-80% alumina. After the metal active components are recovered, there are still a large amount of aluminum-containing residues that need to be recycled and disposed of. Therefore, it is very necessary to achieve the harmless and resource utilization of aluminum resources in waste alumina-supported catalysts. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a method for resource utilization of waste alumina-supported hydrogenation catalysts. The precious metal or transition metal components with higher added value in the waste alumina-supported hydrogenation catalysts are leached and separated with a composite alkaline solution to obtain a residue with an Al content of more than 85%. Without highly purifying Al, the metal can be loaded on the aluminum-containing residue by an impregnation method to prepare a selective hydrogenation catalyst having good selective hydrogenation catalytic activity. The method provided by the present invention can purify the aluminum oxide in the waste alumina carrier efficiently and at low cost, and directly use the leached aluminum-containing residue to prepare a new catalyst, thereby avoiding the complicated process of Al purification and recovery, saving processing costs, improving economic benefits, and having important industrial application value.

[0007] A first aspect of the present invention provides a method for resource utilization of waste alumina-supported hydrogenation catalyst to recover alumina, the method comprising the following steps:

[0008] (1) After pretreatment of the waste alumina-supported hydrogenation catalyst, the loaded metal component A is leached using a composite alkaline leaching agent, solid-liquid separation is performed, and the obtained aluminum-containing residue is roasted to obtain a γ-Al2O3 support;

[0009] (2) impregnating the γ-Al2O3 carrier obtained in step (1) with the loaded metal component B to obtain a catalyst precursor;

[0010] (3) Drying, calcining, and reducing the catalyst precursor obtained in step (2) to obtain a finished catalyst.

[0011] In the above technical solution, the pretreatment in step (1) is high-temperature calcination, the calcination temperature is 400-650° C., and the calcination time is 4-10 hours.

[0012] In the above technical solution, the waste catalyst containing metal component A used in step (1) has a mass content of γ-Al2O3 of 60-85% and a mass content of oxygen-containing compounds of metal component A of 10-35% after pretreatment.

[0013] In the above technical solution, the metal component A in step (1) is selected from one or more of V, Ni, Co, and Mo.

[0014] In the above technical solution, the composite leaching agent in step (1) comprises an alkaline solvent and an additive, wherein the alkaline solvent is selected from ammonia water, and the additive is selected from at least one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, and sodium bicarbonate; preferably, in the composite leaching agent, the concentration of the alkaline solvent is 0.5 to 10 mol / L, preferably 1 to 8 mol / L; the concentration of the additive is 0.5 to 6 mol / L.

[0015] In the above technical solution, the molar ratio of nitrogen to carbon in the composite leaching agent in step (1) is 2.25:1 to 12:1, preferably 4.5:1 to 12:1. As a non-limiting example, it can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, etc.

[0016] In the above technical solution, the reaction temperature of the alkali leaching treatment using the composite alkali leaching agent to leach the loaded metal component A in step (1) is 40-180°C and the reaction time is 1-72 hours. Preferably, the reaction temperature of the alkali leaching treatment is 80-180°C and the reaction time is 1-8 hours.

[0017] In the above technical solution, the calcination conditions in step (1) are calcination at 450-650°C for 4-12 hours.

[0018] In the above technical solution, the leaching rate of Al in the leaching solution obtained by solid-liquid separation in step (1) is less than 1 wt%.

[0019] In the above technical solution, the active metal component B in step (2) includes a main metal and a co-metal additive, wherein the main metal is Ni, and the additive is selected from at least one or more of Cu, V, Pd, Co, and Mo, preferably Cu.

[0020] In the above technical solution, the impregnation in step (2) adopts the equal volume impregnation method.

[0021] In the above technical solution, in step (2), an impregnation solution containing metal component B is prepared, wherein the concentration of metal component B in the impregnation solution is 2-10 mol / L, for example but not limited to 2 mol / L, 2.5 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 8 mol / L, 10 mol / L, etc.

[0022] In the above technical solution, in the metal component B in step (2), the mass ratio of the main metal to the auxiliary agent is 1:1 to 1:5.

[0023] In the above technical solution, in step (3), the catalyst precursor is allowed to stand for 4-6 hours and then dried at a temperature of 100-140° C. for 12-36 hours.

[0024] In the above technical solution, the calcination conditions in step (3) are calcination at a temperature of 450-650° C. for 4-12 hours.

[0025] In the above technical solution, the reduction conditions in step (3) are to reduce the calcined catalyst precursor at 250-400°C for 6-12 hours under a reducing atmosphere of H2. After the reduction is completed, the catalyst must be kept in an atmosphere of H2 or an inert atmosphere (such as N2).

[0026] The second aspect of the present invention provides a hydrogenation catalyst prepared by the resource utilization method of recovering alumina from the above-mentioned discarded alumina-supported hydrogenation catalyst.

[0027] In the above technical solution, the hydrogenation catalyst includes an active metal component B and a γ-Al2O3 carrier.

[0028] In the above technical solution, based on the mass of the hydrogenation catalyst, the mass content of the active metal component B is 5-30%, and the mass content of the γ-Al2O3 carrier is 60-90%.

[0029] In the above technical solution, the active metal component B includes a main metal and a co-metal additive, wherein the main metal is Ni, and the additive is selected from at least one or more of Cu, V, Pd, Co, and Mo, preferably Cu.

[0030] In the above technical solution, in the active metal component B, the main metal accounts for 2.5-15% of the mass of the metal component B, and the additive accounts for 2.5-15% of the mass of the metal component B.

[0031] In the above technical solution, the pore volume of the hydrogenation catalyst is 0.35-0.55cm 3 / g, specific surface area 140-260m 2 / g.

[0032] The third aspect of the present invention provides the use of the above hydrogenation catalyst in the selective hydrogenation of naphthalene to produce tetralin.

[0033] In the above technical solution, in the presence of the catalyst, naphthalene and H2 undergo a selective hydrogenation reaction to obtain the product tetralin.

[0034] In the above technical solution, the reaction evaluation of preparing tetralin by selective hydrogenation of naphthalene is carried out in a single-tube fixed-bed reactor.

[0035] In the above technical solution, the molar ratio of naphthalene and H2 in the raw material is 1:1.2-1:1.8, for example but not limited to the raw material composition of naphthalene:H2=1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, etc.

[0036] In the above technical solution, the reaction pressure is 1.2-1.6 MPa, for example but not limited to, the reaction pressure is 1.20 MPa, 1.25 MPa, 1.30 MPa, 1.35 MPa, 1.40 MPa, 1.45 MPa, 1.50 MPa, 1.55 MPa, 1.60 MPa, etc.

[0037] In the above technical solution, the reaction temperature is 110-170°C, for example but not limited to the reaction temperature of 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, etc.

[0038] In the above technical solution, the raw material volume space velocity is 4-12h -1 , for example but not limited to the raw material volume space velocity of 4h -1 , 5h -1 , 6h -1 , 7h -1 , 8h -1 , 9h -1 , 10h -1 , 11h -1 , 12h -1 wait.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] (1) The method of the present invention can effectively recycle and utilize the aluminum-containing residue generated during the metal recovery process of the discarded alumina-supported hydrogenation catalyst. Through a simple catalyst preparation process, a selective hydrogenation catalyst is prepared from the aluminum-containing residue, which solves the problem of harmless treatment and resource utilization of the aluminum-containing residue, realizes the reuse of aluminum resources, and effectively reduces the processing cost of the discarded alumina-supported catalyst.

[0041] (2) The present invention can realize the resource utilization of aluminum-containing residues recovered from discarded alumina-supported hydrogenation catalysts, and uses porous and thermally stable γ-Al2O3 prepared from the leached residue as a carrier. The prepared catalyst has good catalytic activity in the reaction of selective hydrogenation of naphthalene to prepare tetralin. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the SEM image of the catalyst obtained in Example 1. DETAILED DESCRIPTION

[0043] The following examples will further illustrate the technical solutions provided by the present invention, but the protection scope of the present invention is not limited to these examples.

[0044] In the present invention, the scanning electron microscope (SEM) images of the samples were taken on a Hitachi S-4800II scanning electron microscope.

[0045] In the present invention, the analysis and evaluation of raw materials and products were performed by gas chromatography-mass spectrometry for qualitative characterization and by gas chromatography for quantitative characterization.

[0046] Example 1

[0047] 1. Catalyst Preparation

[0048] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0049] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0050] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0051] For easy comparison, the properties of the catalysts are listed in Table 1.

[0052] 2. Catalyst evaluation

[0053] Catalyst evaluation: The selective hydrogenation of naphthalene to tetralin was carried out in a fixed-bed reactor. The catalyst loading volume was 10 mL, the reaction raw material feed composition (molar ratio) was naphthalene:H2=1:1.2, and the reaction raw material feed volume space velocity was 4h -1 The reaction temperature was 140°C and the reaction pressure was 1.4 MPa. The product composition was analyzed using gas chromatography, and the reaction conversion of naphthalene and the selectivity for tetralin were calculated. For ease of comparison, the reaction evaluation results are listed in Table 2.

[0054] Example 2

[0055] 1. Catalyst Preparation

[0056] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0057] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.4 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0058] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0059] For easy comparison, the properties of the catalysts are listed in Table 1.

[0060] 2. Catalyst evaluation

[0061] Same as Example 1.

[0062] Example 3

[0063] 1. Catalyst Preparation

[0064] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0065] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.6 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0066] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0067] For easy comparison, the properties of the catalysts are listed in Table 1.

[0068] 2. Catalyst evaluation

[0069] Same as Example 1.

[0070] Example 4

[0071] 1. Catalyst Preparation

[0072] (1) A discarded Co-Mo / Al2O3 hydrogenation catalyst was pretreated, i.e., calcined at 450°C for 6h (wherein the content of γ-Al2O3 was 82.2wt.%, and among the metal components, the content of cobalt oxide was 3.0wt.% and the content of molybdenum trioxide was 11.2wt.%, and the rest were impurities). The loaded metal components Co and Mo were leached using a composite alkali leaching agent, wherein the composite alkali leaching agent was 8L of ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate were 0.5mol / L and 2mol / L, respectively, and the molar ratio of N to C was 2.25:1. The leaching conditions were stirring, leaching temperature of 90°C, and reaction time of 2h. The reactants were separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 85.4% for Co, 79.2% for Mo, and 0% for Al.

[0073] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0074] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0075] For easy comparison, the properties of the catalysts are listed in Table 1.

[0076] 2. Catalyst evaluation

[0077] Same as Example 1.

[0078] Example 5

[0079] 1. Catalyst Preparation

[0080] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 10mol / L and 1mol / L respectively, wherein the molar ratio of N to C is 12:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 91.5% for Co, 92.6% for Mo, and 0% for Al.

[0081] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0082] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0083] For easy comparison, the properties of the catalysts are listed in Table 1.

[0084] 2. Catalyst evaluation

[0085] Same as Example 1.

[0086] Example 6

[0087] 1. Catalyst Preparation

[0088] (1) A discarded Co-Mo / Al2O3 hydrogenation catalyst was pretreated, i.e., calcined at 450°C for 6 h (wherein the content of γ-Al2O3 was 82.2 wt.%, and among the metal components, the content of cobalt oxide was 3.0 wt.% and the content of molybdenum trioxide was 11.2 wt.%, and the rest were impurities). The loaded metal components Co and Mo were leached using a composite alkali leaching agent, wherein the composite alkali leaching agent was 8 L of ammonia water and sodium carbonate solution, wherein the concentrations of ammonia water and sodium carbonate were 9 mol / L and 2 mol / L, respectively, and wherein the molar ratio of N to C was 4.5:1. The leaching conditions were stirring, a leaching temperature of 90°C, and a reaction time of 2 h. The reactants were separated, including a filtrate and an aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 88.1% for Co, 84.6% for Mo, and 0% for Al.

[0089] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0090] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0091] For easy comparison, the properties of the catalysts are listed in Table 1.

[0092] 2. Catalyst evaluation

[0093] Same as Example 1.

[0094] Example 7

[0095] 1. Catalyst Preparation

[0096] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0097] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1 mol / L cobalt nitrate and 1.2 mol / L nickel ammine complex, performing equal volume impregnation to prepare a catalyst precursor;

[0098] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0099] For easy comparison, the properties of the catalysts are listed in Table 1.

[0100] 2. Catalyst evaluation

[0101] Same as Example 1.

[0102] Example 8

[0103] The method described in Example 1 is as follows, except that in the catalyst evaluation:

[0104] Catalyst evaluation: The selective hydrogenation of naphthalene to tetralin was carried out in a fixed-bed reactor. The catalyst loading volume was 10 mL, the reaction raw material feed composition (molar ratio) was naphthalene:H2=1:1.2, and the reaction raw material feed volume space velocity was 5 h -1The reaction temperature was 140°C and the reaction pressure was 1.4 MPa. The product composition was analyzed using gas chromatography, and the reaction conversion of naphthalene and the selectivity for tetralin were calculated. For ease of comparison, the reaction evaluation results are listed in Table 2.

[0105] Example 9

[0106] The method described in Example 1 is as follows, except that in the catalyst evaluation:

[0107] Catalyst evaluation: The selective hydrogenation of naphthalene to tetralin was carried out in a fixed-bed reactor with a catalyst loading volume of 10 mL and a feed composition (molar ratio) of naphthalene:H2=1:1.2. The feed volumetric space velocity of the reaction raw materials was 6 h -1 The reaction temperature was 140°C and the reaction pressure was 1.4 MPa. The product composition was analyzed using gas chromatography, and the reaction conversion of naphthalene and the selectivity for tetralin were calculated. For ease of comparison, the reaction evaluation results are listed in Table 2.

[0108] Example 10

[0109] The method described in Example 1 is as follows, except that in the catalyst evaluation:

[0110] Catalyst evaluation: The selective hydrogenation of naphthalene to tetralin was carried out in a fixed-bed reactor. The catalyst loading volume was 10 mL, the reaction raw material feed composition (molar ratio) was naphthalene:H2=1:1.2, and the reaction raw material feed volume space velocity was 4h -1 The reaction temperature was 150°C and the reaction pressure was 1.4 MPa. The product composition was analyzed by gas chromatography, and the reaction conversion of naphthalene and the selectivity for tetralin were calculated. For ease of comparison, the reaction evaluation results are listed in Table 2.

[0111] Example 11

[0112] The method described in Example 1 is as follows, except that in the catalyst evaluation:

[0113] Catalyst evaluation: The selective hydrogenation of naphthalene to tetralin was carried out in a fixed-bed reactor. The catalyst loading volume was 10 mL, the reaction raw material feed composition (molar ratio) was naphthalene:H2=1:1.2, and the reaction raw material feed volume space velocity was 4h -1 The reaction temperature was 160°C and the reaction pressure was 1.4 MPa. The product composition was analyzed using gas chromatography, and the reaction conversion of naphthalene and the selectivity for tetralin were calculated. For ease of comparison, the reaction evaluation results are listed in Table 2.

[0114] Comparative Example 1

[0115] 1. Catalyst Preparation

[0116] (1) A discarded Co-Mo / Al2O3 hydrogenation catalyst was pretreated, i.e., calcined at 450°C for 6 h (wherein the content of γ-Al2O3 was 82.2 wt.%, and among the metal components, the content of cobalt oxide was 3.0 wt.% and the content of molybdenum trioxide was 11.2 wt.%, and the rest were impurities). The loaded metal components Co and Mo were leached using a composite alkali leaching agent, wherein the composite alkali leaching agent was 8 L of ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate were 0.1 mol / L and 1 mol / L, respectively, and wherein the molar ratio of N to C was 2.1:1. The leaching conditions were stirring, a leaching temperature of 90°C, and a reaction time of 2 h. The reactants were separated, including a filtrate and an aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 81.4% for Co, 78.7% for Mo, and 0% for Al.

[0117] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0118] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0119] For easy comparison, the properties of the catalysts are listed in Table 1.

[0120] 2. Catalyst evaluation

[0121] Same as Example 1.

[0122] Comparative Example 2

[0123] 1. Catalyst Preparation

[0124] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 12mol / L and 1mol / L respectively, wherein the molar ratio of N to C is 14:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 91.2% for Co, 91.8% for Mo, and 6.7% for Al.

[0125] (2) impregnating the γ-Al2O3 support obtained in step (1) in a mixed solution of 1.2 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex, performing equal volume impregnation to prepare a catalyst precursor;

[0126] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0127] For easy comparison, the properties of the catalysts are listed in Table 1.

[0128] 2. Catalyst evaluation

[0129] Same as Example 1.

[0130] Comparative Example 3

[0131] 1. Catalyst Preparation

[0132] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0133] Step (2) The γ-Al2O3 carrier obtained in step (1) is immersed in a 1.2 mol / L nickel-ammine complex solution, and equal volume impregnation is performed to prepare a catalyst precursor.

[0134] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 350°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0135] For easy comparison, the properties of the catalysts are listed in Table 1.

[0136] 2. Catalyst evaluation

[0137] Same as Example 1.

[0138] Comparative Example 4

[0139] 1. Catalyst Preparation

[0140] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0141] Step (2) The γ-Al2O3 carrier obtained in step (1) is impregnated in 1.0 mol / L copper ammonia complex and 1.2 mol / L nickel ammonia complex solutions, and equal volume impregnation is performed to prepare a catalyst precursor.

[0142] (3) The catalyst precursor was allowed to stand for 4 hours, dried at 120°C for 24 hours, calcined in a muffle furnace at 550°C, and then placed in a reactor and reduced at 250°C in a H2 atmosphere for 6 hours to obtain a finished catalyst.

[0143] For easy comparison, the properties of the catalysts are listed in Table 1.

[0144] 2. Catalyst evaluation

[0145] Same as Example 1.

[0146] Comparative Example 5

[0147] 1. Catalyst Preparation

[0148] (1) Take the discarded Co-Mo / Al2O3 hydrogenation catalyst, pre-treat it, that is, calcine it at 450°C for 6h, (wherein, the content of γ-Al2O3 is 82.2wt.%, and among the metal components, the content of cobalt oxide is 3.0wt.% and the content of molybdenum trioxide is 11.2wt.%, and the rest are impurities), and use a composite alkali leaching agent to leach the loaded metal components Co and Mo, wherein the composite alkali leaching agent is 8L ammonia water and ammonium carbonate solution, wherein the concentrations of ammonia water and ammonium carbonate are 2mol / L and 0.8mol / L respectively, wherein the molar ratio of N to C is 4.5:1. The leaching conditions are to start stirring, the leaching temperature is 90°C, and the reaction time is 2h. The reactants are separated, including filtrate and aluminum-containing residue. The aluminum-containing residue was calcined at 450°C for 4 hours to obtain a γ-Al2O3 carrier. The filtrate was then analyzed using an inductively coupled plasma optical emission spectrometer (ICP, Varian, 725-ES) to measure the concentrations of Co, Mo, and Al. The leaching rate, defined as the mass of metal in the filtrate divided by the total mass of metal in the feedstock, was calculated based on the ICP results to be 90.2% for Co, 87.9% for Mo, and 0% for Al.

[0149] After the γ-Al2O3 carrier is obtained in step (1), the γ-Al2O3 is directly filled into the reactor to evaluate the catalyst activity.

[0150] Table 1 Composition and properties of hydrogenation catalysts obtained in each example

[0151]

[0152] Table 2 Evaluation conditions and evaluation results of the hydrogenation catalysts obtained in each case

[0153]

[0154]

Claims

1. A method for recycling alumina from discarded alumina-supported hydrogenation catalysts, characterized in that: The method comprises the following steps: (1) After pretreatment of the waste alumina-supported hydrogenation catalyst, the loaded metal component A is leached using a composite alkaline leaching agent, solid-liquid separation is performed, and the obtained aluminum-containing residue is roasted to obtain a γ-Al2O3 support; (2) impregnating the γ-Al2O3 carrier obtained in step (1) with the active metal component B to obtain a catalyst precursor; (3) drying, calcining, and reducing the catalyst precursor obtained in step (2) to obtain a finished catalyst; The pretreatment in step (1) is high-temperature roasting, and the roasting temperature is 400~650℃; The waste catalyst containing metal component A used in step (1) has a mass content of 60-85% of γ-Al2O3 and a mass content of 10-35% of oxygen-containing compounds of metal component A after pretreatment, and the sum of the mass contents of the components is 100%; The metal component A in step (1) is selected from one or more of V, Ni, Co, and Mo; The composite alkaline leaching agent in step (1) comprises an alkaline solvent and an additive, wherein the alkaline solvent is selected from ammonia water, and the additive is selected from at least one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, and sodium bicarbonate; in the composite alkaline leaching agent, the concentration of the alkaline solvent is 0.5-10 mol / L, and the concentration of the additive is 0.5-6 mol / L; The molar ratio of nitrogen to carbon in the composite alkaline leaching agent in step (1) is 2.25:1 to 12:1; The active metal component B in step (2) comprises a main metal and a co-metal additive, wherein the main metal is Ni and the additive is selected from at least one of Cu, V, Pd, Co, and Mo; In the active metal component B in step (2), the mass ratio of the main metal to the auxiliary agent is 1:1 to 1:

5.

2. The method according to claim 1, characterized in that In the composite alkaline leaching agent, the concentration of the alkaline solvent is 1-8 mol / L.

3. The method according to claim 1, characterized in that In step (2), an impregnation solution containing active metal component B is prepared, wherein the concentration of active metal component B in the impregnation solution is 2-10 mol / L.

4. The method according to claim 1, wherein The reduction conditions in step (3) are to reduce the calcined catalyst precursor at 250-400° C. for 6-12 hours under a reducing atmosphere.

5. A hydrogenation catalyst prepared by the resource utilization method of recovering alumina from discarded alumina-supported hydrogenation catalyst according to any one of claims 1 to 4.

6. The hydrogenation catalyst according to claim 5, characterized in that Based on the mass of the hydrogenation catalyst, the mass content of the active metal component B is 5-30%, the mass content of the γ-Al2O3 carrier is 60-90%, and the sum of the mass contents of each component in the hydrogenation catalyst is 100%.

7. The hydrogenation catalyst according to claim 5, characterized in that The pore volume of the hydrogenation catalyst is 0.35-0.55 cm 3 / g, with a specific surface area of ​​140-260m 2 / g.

8. Use of the hydrogenation catalyst according to any one of claims 5 to 7 in the reaction of preparing tetralin by selective hydrogenation of naphthalene.

9. The use according to claim 8, characterized in that In the presence of the hydrogenation catalyst, naphthalene undergoes a selective hydrogenation reaction with H2 to obtain the product tetralin.

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