Preparation method and application of acetate hydrogenation catalyst

Abstract

The invention provides an acetate hydrogenation catalyst and a preparation method and application thereof.The preparation method comprises the steps that firstly, reaction is conducted in a supergravity rotating packed bed, and a nano-silica intercalation modified hydrotalcite-like structure precursor containing an organic carbon source and a certain content of active components is obtained; secondly, the active component and the auxiliary agent are deposited on the surface of the hydrotalcite-like precursor in a precipitation and deposition mode, the acetic ester hydrogenation catalyst is obtained after aging-calcination treatment, under the optimal reaction condition, the conversion rate of acetic ester is larger than or equal to 99.5%, the selectivity of ethyl alcohol is larger than or equal to 99.4%, after stable operation is conducted for 1000 h, the performance is not attenuated, the excellent hydrogenation performance and stability are shown, and the catalyst is suitable for industrial production. The synthesis method combining precursor in-situ modification and precipitation deposition has the advantages of being high in efficiency, few in three wastes and suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing hydrogenation catalysts, and in particular to an acetate hydrogenation catalyst, a preparation method thereof, and applications thereof. Background Art

[0002] As a fundamental organic chemical raw material, ethanol is widely used in the chemical, pharmaceutical, food, and fuel industries, and can partially replace ethylene in the production of downstream products. Furthermore, ethanol is gaining increasing international attention as a clean and environmentally friendly fuel, oil quality improver, and gasoline alternative. Reducing dependence on gasoline through the development of fuel ethanol will help ensure national energy security and reduce my country's reliance on foreign oil resources. Furthermore, fuel ethanol's environmentally friendly, low-carbon, pollution-free, and clean nature make it crucial for achieving sustainable development.

[0003] With the development of the fiber, coating, and adhesive industries, my country's polyvinyl alcohol (PVA) industry is rapidly expanding its production capacity, resulting in a significant overcapacity of its byproduct, methyl acetate. Furthermore, acetic acid, as an upstream raw material for ethanol, currently faces overcapacity, insufficient utilization rates, and low prices. Furthermore, as production capacity continues to expand, the imbalance between supply and demand is further exacerbated. Consequently, it is urgent to develop new growth points for acetic acid demand to address the prominent contradiction between rapid production capacity growth and relatively lagging demand. Ethanol, as a downstream product of acetic acid, has broad market applications.

[0004] Currently, copper catalysts are widely used in the industry for the hydrogenation of acetate to ethanol. CN117920210A discloses a metal complex-derived acetate hydrogenation catalyst and its preparation method. The catalyst is selected from Zr, Ce, and Al, coordinated with ligands such as terephthalic acid, trimesic acid, and 2-aminoterephthalic acid, and used as a carrier. The active components are primarily copper, palladium, platinum, and rhodium. Both the ligands and the precious metal active components are very expensive. CN112973689A uses a method of multiple impregnation spray drying and calcination to prepare a boron-doped acetate hydrogenation catalyst. The multiple calcination process increases energy consumption and processing costs during the catalyst synthesis process. CN103007943, CN102974382, CN103447059B, and CN102423710 each disclose a copper-based catalyst for the hydrogenation of acetate to ethanol and its preparation method. Ammonia water is used as a precipitant, and Cu is deposited by heating and distilling ammonia. This method releases a large amount of ammonia gas, is time-consuming, energy-intensive, and environmentally polluting, requiring the use of protective and recovery devices. CN103230795 discloses a copper-based catalyst for hydrogenating acetate to ethanol and a preparation method thereof. The catalyst is prepared by a coprecipitation method, and the pH value is adjusted to 8-9 with NaOH. However, the methyl acetate conversion rate is only 84%.

[0005] As can be seen, acetate hydrogenation to ethanol typically uses aluminum oxide, silicon oxide, or zirconium oxide as supports, often suffering from shortcomings such as low acetate conversion, cumbersome catalyst preparation methods, and poor stability. Furthermore, these supports fail to limit the particle size and dispersion of the copper species, leading to their tendency to aggregate into large particles during the reaction, significantly reducing the dispersion of the catalyst's active sites and causing irreversible deactivation. This leads to poor catalyst stability, further hindering its industrial application and development. The present invention utilizes a hydrotalcite-like structure modified by intercalation as a support, effectively preventing copper particle agglomeration and demonstrating excellent stability and industrial prospects. Summary of the Invention

[0006] Based on the above technical problems, the present invention proposes an acetate hydrogenation catalyst and a preparation method thereof.

[0007] A method for preparing an acetate hydrogenation catalyst comprises the following steps: (1) Copper salt and aluminum salt are mixed to prepare a metal solution, wherein the molar ratio of copper salt to aluminum salt is (0.2-0.5):1, and then an organosilicon source and a treating agent A are added to the metal solution to prepare a mixed solution; (2) The mixed solution and the alkaline precipitant solution are transported to a high-gravity rotating packed bed via a peristaltic pump, the pH value of the system is controlled to be 7-8, and the reaction is carried out at a temperature of 70-90°C. After aging, a precursor of a CuAl-LDH hydrotalcite-like structure modified by nano-silica intercalation containing an organic carbon source and a small amount of active components is obtained; The rotation speed of the high gravity rotating packed bed is 600-1000 rpm; the volume flow ratio of the mixed solution to the alkaline precipitant solution is (4-10):1; (3) The precursor is ultrasonically dispersed into an aqueous solution containing a treating agent B to obtain a dispersed solution, and a mixed metal solution of copper salt, auxiliary agent M, and auxiliary agent N and the alkaline precipitant solution are added to the dispersed solution in a parallel manner. The pH value of the system is controlled to be 7-8 at a temperature of 70-90°C. After aging, filtering, and washing, the catalyst is calcined under a protective atmosphere to obtain a carbon-modified silica intercalation-modified composite catalyst.

[0008] Preferably, in steps (1) and (3), the copper salt is any one of copper nitrate, chloride, sulfate, and acetate, or a combination of two thereof, and the aluminum salt is one of aluminum nitrate, chloride, sulfate, and acetate, or a combination of two thereof.

[0009] Preferably, in step (1), the treatment agent A is one of diethanolamine, diisopropanolamine, triisopropanolamine, N,N-dimethylethanolamine, hexamethylenetetramine, acetamide, diphenylamine, and p-methylaniline, or a combination of any of the above, and the concentration of the treatment agent A is 0.5-3 wt% of the total mass of the mixed solution.

[0010] Preferably, in steps (1) and (2), the alkaline precipitant is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, and potassium hydroxide.

[0011] Preferably, in step (1), the organic silicon source is at least one of methyl orthosilicate and ethyl orthosilicate, and its content is 0.1% to 2% of the total mass of the mixed solution.

[0012] Preferably, in steps (1) and (2), the aging time is 2 to 10 hours, and the aging temperature is 70 to 90°C.

[0013] Preferably, in step (3), the molar ratio of the copper salt, the auxiliary agent M, and the auxiliary agent N is 1:(0.5-1):(0.01-0.05).

[0014] Preferably, the auxiliary agent M is at least one of Zn and Zr; the auxiliary agent N is at least one of Mn, Fe, Co, Ni, Ce, La, and Mo.

[0015] Preferably, in step (3), the treatment agent B is one of polyethylene glycol, OP-20, sodium stearate, fatty acid polyethylene glycol ester, or any combination thereof, and its content is 0.5%-1.5% of the total mass of the dispersion solution.

[0016] Preferably, the calcination temperature is 300-500° C., the calcination time is 3-6 hours, and the calcination atmosphere is either nitrogen or argon.

[0017] The acetate hydrogenation catalyst includes a carrier, an active component supported on the carrier, and an additive. The active component is Cu, the carrier is a carbon-modified and silica-intercalated hydrotalcite-like carrier, and the additives are M and N. After reduction, the weight ratio is as follows: 5 to 40 parts of Cu, 30 to 60 parts of Al, 0.1 to 2 parts of carbon, 0.5 to 5 parts of SiO2, 10 to 30 parts of additive M, and 1 to 5 parts of additive N.

[0018] The present invention provides application of an acetate hydrogenation catalyst in catalytic hydrogenation of methyl acetate to ethanol.

[0019] Preferably, the conditions of the catalytic hydrogenation include: reaction temperature of 150-220°C, reaction pressure of 2.0-3.0 MPa, acetate space velocity of 0.5-2.0 g / h, hydrogen to ester ratio of 2-50 Beneficial effects: 1. The present invention uses a hydrotalcite-like structure with a high specific surface area and porous structure as a carrier. The highly dispersed nano-silica intercalation-modified hydrotalcite-like structure enhances the strong metal-carrier interaction. The interlayer confinement effect is utilized to achieve an orderly arrangement of active sites between the layers, thereby enhancing the electron transfer effect between the active components in the inner and outer layers. The synergistic effect of carbon modification and organic dispersant further increases the dispersion of the active components, thereby suppressing the problem of active component agglomeration during the reaction process, and improving the service life of the catalyst and the hydrogenation effect. 2. The above characteristics enable the catalyst to exhibit excellent performance advantages in the acetate hydrogenation process, reducing the formation of side reaction fusel alcohols. The catalyst synthesized by the above method has a methyl acetate conversion rate of ≥99.5% and an ethanol selectivity of ≥99.4%. The performance does not decay after 1000 hours of stable operation. In addition, this method has the characteristics of simple operation, short process, and easy industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the XRD pattern of the catalyst proposed in some embodiments of the present invention; Figure 2 This is a stability test chart of the methyl acetate hydrogenation catalyst of the present invention. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0022] In the present invention, the acetate hydrogenation catalyst is preferably subjected to a reduction treatment before use to reduce the CuO in the acetate hydrogenation catalyst to Cu, thereby having better activity. The resulting activated catalyst is then used to catalyze the hydrogenation of acetate to produce ethanol.

[0023] In the present invention, the reduction treatment is preferably carried out in a hydrogen atmosphere, the temperature of the reduction treatment is preferably 150-320° C., more preferably 300° C., and the time is preferably 8-12 h, preferably 10 h.

[0024] The acetate hydrogenation catalyst of the present invention is preferably used for the hydrogenation of methyl acetate to produce ethanol, but its use in other acetate hydrogenation reactions is not excluded. When the catalyst is used in the acetate hydrogenation reaction to produce ethanol, under the reaction conditions of a reaction temperature of 150-240°C, a reaction pressure of 1.0-3.0 MPa, an acetate space velocity of 0.5-3.0 g / hour, and a hydrogen-to-ester ratio of 2-100, the acetate conversion rate exceeds 99.5%, and the ethanol selectivity exceeds 99.4%. In particular, the acetate hydrogenation catalyst of the present invention maintains high acetate hydrogenation activity and ethanol selectivity at relatively low temperatures. Therefore, when used in acetate hydrogenation reactions, the catalyst of the present invention exhibits excellent catalytic activity and temperature stability. Specific examples are provided below.

[0025] Example 1 (1) Weigh 5 g of copper nitrate trihydrate and 40 g of aluminum nitrate nonahydrate to prepare a 0.5 mol / L copper and aluminum mixed metal solution. Add 1 ml of ethyl orthosilicate and 1.75 g of diethanolamine, mix well, and then transport it to a high-gravity rotating packed bed in parallel with 150 g / L sodium carbonate solution through a peristaltic pump. Under the condition of a rotation speed of 800 rpm, the reaction temperature is set to 80 ° C, and the pH of the reaction system is controlled to 8. After 4 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0026] (2) The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 1 g / L polyethylene glycol. A mixed metal solution containing 50 g / L copper nitrate, 20 g / L zinc nitrate, and 3 g / L magnesium nitrate and a 150 g / L sodium carbonate solution were dripped into the above solution in parallel. The reaction temperature was set to 70°C. By adjusting the feed rates of the two, the pH of the system was maintained at 7. After the reaction was completed, the product was aged for 4 hours. The synthesized product was repeatedly washed 3 times with 50°C deionized water and dried at 110°C for 4 hours. The product was placed in a tube furnace and calcined at 400°C for 3 hours under a nitrogen atmosphere. The product was taken out for tableting and screening. A sample with a mesh size of 40-60 was selected for evaluation and analysis, which was recorded as Example 1.

[0027] Comparative Example 1 The experimental process of Example 1 was repeated without adding diethanolamine to the copper and aluminum mixed metal solution in Example 1. The resulting catalyst was designated as Example 1-1.

[0028] Comparative Example 2 The experimental process of Example 1 was repeated without adding ethyl orthosilicate to the copper and aluminum mixed metal solution in Example 1. The resulting catalyst was designated as Example 1-2.

[0029] Example 2 (1) Weigh 12 g of copper nitrate trihydrate and 45 g of aluminum nitrate nonahydrate to prepare a 1 mol / L copper and aluminum mixed metal solution. Add 0.5 ml of ethyl orthosilicate and 2 g of diethanolamine, mix well, and then transport it to a high-gravity rotating packed bed in parallel with a mixed solution of 80 g / L sodium carbonate and 20 g / L sodium hydroxide through a peristaltic pump. Under the condition of a rotation speed of 600 rpm, the reaction temperature is set to 80 ° C, and the pH of the reaction system is controlled to 8. After 3 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0030] (2) The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 2 g / L of OP-20. A mixed metal solution containing 60 g / L of copper nitrate, 40 g / L of zinc nitrate, and 2 g / L of magnesium nitrate and a mixed solution of 50 g / L of sodium carbonate and 15 g / L of sodium hydroxide were dripped into the above solution in parallel. The reaction temperature was set to 80°C. By adjusting the feed rates of the two, the pH was maintained at 7. After the reaction was completed, the product was aged for 8 hours. The synthesized product was repeatedly washed three times with deionized water at 50°C and dried at 110°C for 4 hours. The product was placed in a tube furnace and calcined at 450°C for 3 hours under a nitrogen atmosphere. The product was taken out for tableting and screening. A sample with a mesh size of 40-60 was selected for evaluation and analysis, which was recorded as Example 2.

[0031] Example 3 (1) Weigh 20 g of copper nitrate trihydrate and 65 g of aluminum nitrate nonahydrate to prepare a 2 mol / L copper and aluminum mixed metal solution. Add 0.8 ml of ethyl orthosilicate and 2 g of hexamethylenetetramine, mix well, and then transport it to a high-gravity rotating packed bed in parallel with a mixed solution of 60 g / L sodium carbonate and 40 g / L ammonium bicarbonate through a peristaltic pump. Under the condition of a rotation speed of 600 rpm, the reaction temperature is set to 90 ° C, and the pH of the reaction system is controlled to 8. After 3 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0032] (2) The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 0.5 g / L sodium stearate, and a mixed metal solution containing 55 g / L copper sulfate, 40 g / L zirconium nitrate, and 2 g / L cerium nitrate and a mixed solution of 50 g / L sodium carbonate and 15 g / L ammonium bicarbonate were dripped into the above solution in a parallel flow manner. The reaction temperature was set to 90 ° C. By adjusting the feed rate of the two, the pH was maintained at 8. After the reaction was completed, the product was aged for 8 hours, and the synthesized product was repeatedly washed 3 times with 50 ° C deionized water. After drying at 110 ° C for 4 hours, it was placed in a tube furnace and calcined at 450 ° C for 3 hours under a nitrogen atmosphere. It was taken out for tableting and screening. A sample with a mesh size of 40-60 was selected for evaluation and analysis, which was recorded as Example 3.

[0033] Example 4 (1) Weigh 20 g of copper sulfate pentahydrate and 80 g of aluminum sulfate to prepare a 2 mol / L copper-aluminum mixed metal solution. Add 1 ml of ethyl orthosilicate and 1.5 g of acetamide, mix well, and then transport it to a high-gravity rotating packed bed in parallel with a mixed solution of 60 g / L sodium carbonate and 40 g / L ammonium bicarbonate through a peristaltic pump. Under the condition of a rotation speed of 700 rpm, the reaction temperature is set to 90 ° C, and the pH of the reaction system is controlled to 8. After 3 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0034] (2) The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 1 g / L fatty acid polyethylene glycol ester, and a mixed metal solution containing 40 g / L copper sulfate, 20 g / L zirconium nitrate and aluminum chloride, 2 g / L nickel nitrate and lanthanum nitrate, and a mixed solution of 30 g / L ammonium carbonate and 15 g / L sodium hydroxide were dripped into the above solution in a parallel flow manner. The reaction temperature was set to 90°C. By adjusting the feed rate of the two, the pH was maintained at 8. After the reaction was completed, the product was aged for 8 hours, and the synthesized product was repeatedly washed 3 times with 50°C deionized water. After drying at 110°C for 4 hours, it was placed in a tube furnace and calcined at 500°C for 3 hours under a nitrogen atmosphere. The product was taken out for tableting and screening. A sample with a size of 40-60 was selected for evaluation and analysis, which was recorded as Example 4.

[0035] Example 5 (1) Weigh 15 g of copper chloride and 60 g of aluminum chloride to prepare a 2 mol / L copper-aluminum mixed metal solution. Add 1 ml of methyl orthosilicate and 1.5 g of diphenylamine, mix well, and then transport it to a high-gravity rotating packed bed in parallel with a mixed solution of 60 g / L potassium carbonate and 40 g / L sodium bicarbonate through a peristaltic pump. Under the condition of a rotation speed of 650 rpm, the reaction temperature is set to 90 ° C, and the pH of the reaction system is controlled to 8. After 3 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0036] (2) The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 1 g / L fatty acid polyethylene glycol ester, and a mixed metal solution containing 40 g / L copper acetate, 20 g / L zirconium nitrate and aluminum chloride, 2 g / L molybdenum nitrate and manganese nitrate, and a mixed solution of 15 g / L sodium carbonate and 20 g / L potassium hydroxide were dripped into the above solution in a parallel flow manner. The reaction temperature was set to 85°C. By adjusting the feed rate of the two, the pH was maintained at 8. After the reaction was completed, the product was aged for 6 hours, and the synthesized product was repeatedly washed 3 times with 50°C deionized water. After drying at 110°C for 4 hours, it was placed in a tube furnace and calcined at 450°C for 3 hours under a nitrogen atmosphere. The product was taken out for tableting and screening. A sample with a mesh size of 40-60 was selected for evaluation and analysis, which was recorded as Example 5.

[0037] Example 6 (1) Weigh 20 g of copper acetate and 65 g of aluminum acetate to prepare a 1.8 mol / L copper-aluminum mixed metal solution. Add 1.5 ml of ethyl orthosilicate and 1.5 g of p-methylaniline, mix well, and then transport it to a high-gravity rotating packed bed in parallel with a mixed solution of 60 g / L potassium carbonate and 40 g / L sodium carbonate through a peristaltic pump. Under the condition of a rotation speed of 850 rpm, the reaction temperature is set to 90 ° C, and the pH of the reaction system is controlled to 8. After 3 hours, the reaction is completed. After filtration, a hydrotalcite-like structure precursor modified by nano-silica intercalation loaded with an organic carbon source is obtained.

[0038] The precursor obtained in step (1) was ultrasonically dispersed into an aqueous solution containing 1 g / L of sodium stearate. A mixed metal solution containing 30 g / L of copper chloride, 15 g / L of zirconium nitrate and aluminum chloride, 2 g / L of cobalt nitrate and nickel nitrate, and a mixed solution of 20 g / L of sodium carbonate and 30 g / L of potassium bicarbonate were dripped into the above solution in parallel. The reaction temperature was set at 90°C. By adjusting the feed rates of the two, the pH was maintained at 8. After the reaction was completed, the product was aged for 8 hours, and the synthesized product was repeatedly washed three times with deionized water at 50°C. After drying at 110°C for 4 hours, it was placed in a tube furnace and calcined at 500°C for 3 hours under a nitrogen atmosphere. The product was taken out for tableting and screening. A sample with a mesh size of 40-60 was selected for evaluation and analysis, which was recorded as Example 6.

[0039] Table 1 - Physical properties of catalysts Catalyst name <![CDATA[S BET m 2 / g]]> <![CDATA[V 孔 ml / g]]> <![CDATA[D 粒径 nm]]> Example 1 230 0.67 21.45 Comparative Example 1-1 126 0.32 10.25 Comparative Example 1-2 156 0.34 11.30 Example 2 258 0.62 21.55 Example 3 247 0.59 21.03 Example 4 268 0.70 22.32 Example 5 270 0.73 20.34 Example 6 266 0.65 21.67 The catalysts obtained in Examples 1-6 and Comparative Examples 1-1 and 1-2 were used in the reaction of gas-phase hydrogenation of methyl acetate to produce ethanol, and the catalytic performance of the catalysts was investigated.

[0040] The reduction and evaluation process of the above-mentioned catalyst was carried out in a laboratory-scale fixed-bed reactor. The catalyst was fixed in the constant temperature section of the reactor with quartz sand. The catalyst loading amount was 1 gram, the reduction temperature was 250°C, the reducing gas H2 flow rate was 50 ml / min, and the reduction time was 10 hours. After the reduction was completed, the temperature was lowered to 150°C~220°C, and the reactor pressure was increased to 2.0~3.0 MPa.

[0041] Methyl acetate is delivered by a liquid feed pump, vaporized, and then mixed with hydrogen before entering the reactor. The methyl acetate space velocity is 0.5-2.0 g / h, and the hydrogen-to-ester ratio (molar ratio) is 2-50. The condensed liquid product is taken out at regular intervals, and the composition of the liquid product is analyzed by gas chromatograph, and the methyl acetate conversion rate and ethanol selectivity are calculated.

[0042] The conversion rate of methyl acetate and the selectivity of ethanol are calculated according to the following formula: Methyl acetate conversion = (methyl acetate feed mass - methyl acetate mass in liquid product) / methyl acetate feed mass; Ethanol selectivity = mass of methyl acetate consumed to produce ethanol / mass of all converted methyl acetate.

[0043] The experiments were conducted under the following reaction conditions: reaction temperature: 200°C, 180°C, or 150°C; reaction pressure: 2-3 MPa; methyl acetate space velocity: 1.5 g / h; hydrogen-to-ester ratio (molar ratio): 30. The experimental results are shown in Table 2 below.

[0044] Table 2 - Performance of catalysts under different evaluation conditions Catalyst name Temperature / ℃ Pressure / Mpa Conversion rate of methyl acetate / % Ethanol selectivity / % Example 1 200 3 99.4 99.2 Comparative Example 1-1 200 3 85.1 84.2 Comparative Example 1-2 200 3 84.6 89.8 Example 2 200 3 99.4 99.3 Example 3 200 3 99.0 99.4 Example 4 200 3 99.2 99.0 Example 5 200 3 99.1 99.0 Example 6 200 3 99.5 99.2 Example 1 180 3 98.4 98.9 Comparative Example 1-1 180 3 82.6 83.7 Comparative Example 1-2 180 3 81.8 88.0 Example 2 180 3 98.3 99.0 Example 3 180 3 97.9 99.2 Example 4 180 3 98.2 99.1 Example 5 180 3 98.1 99.0 Example 6 180 3 98.3 99.1 Example 1 150 3 98.2 98.8 Comparative Example 1-1 150 3 78.9 77.3 Comparative Example 1-2 150 3 76.6 71.5 Example 2 150 3 98.2 98.9 Example 3 150 3 97.6 99.1 Example 4 150 3 98.1 99.0 Example 5 150 3 98.4 98.7 Example 6 150 3 98.3 99.2 Example 1 150 2 97.6 98.1 Comparative Example 1-1 150 2 70.5 55.1 Comparative Example 1-2 150 2 60.5 35.1 Example 2 150 2 96.9 97.1 Example 3 150 2 96.5 97.4 Example 4 150 2 96.1 97.0 Example 5 150 2 96.6 97.5 Example 6 150 2 96.4 97.7 The results in Table 2 indicate that the acetate hydrogenation catalyst of the present invention achieves unexpected technical effects. Under the same evaluation conditions, the acetate hydrogenation catalyst exhibits significantly improved methyl acetate conversion and ethanol selectivity compared to the catalyst synthesized without the addition of a treating agent. This demonstrates that the catalytic performance of the acetate hydrogenation catalyst of the present invention is superior to that of existing acetate hydrogenation catalysts.

[0045] The terms and expressions used in this specification are used as terms and expressions of description only, and not of limitation, and there is no intention in the use of these terms and expressions to exclude any equivalents of the features shown and described or their components.

[0046] Although several embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. On the contrary, it should be appreciated by those skilled in the art that any variations and improvements may be made to these embodiments without departing from the principles of the present invention. The scope of protection of the present invention is determined by the appended claims and their equivalents.

Claims

1. A method for preparing an acetate hydrogenation catalyst, characterized in that: The following steps are involved: (1) Copper salt and aluminum salt are mixed to prepare a metal solution, wherein the molar ratio of copper salt to aluminum salt is (0.2-0.5):1, and then an organosilicon source and a treating agent A are added to the metal solution to prepare a mixed solution; (2) The mixed solution and the alkaline precipitant solution are transported to a high-gravity rotating packed bed via a peristaltic pump, the pH value of the system is controlled to be 7-8, and the reaction is carried out at a temperature of 70-90°C. After aging, a precursor of a CuAl-LDH hydrotalcite-like structure modified by nano-silica intercalation containing an organic carbon source and a small amount of active components is obtained; The rotation speed of the high gravity rotating packed bed is 600-1000 rpm; the volume flow ratio of the mixed solution to the alkaline precipitant solution is (4-10):1; (3) The precursor is ultrasonically dispersed into an aqueous solution containing a treating agent B to obtain a dispersed solution, and a mixed metal solution of copper salt, auxiliary agent M, and auxiliary agent N and the alkaline precipitant solution are added to the dispersed solution in a parallel manner. The pH value of the system is controlled to be 7-8 at a temperature of 70-90°C. After aging, filtering, and washing, the catalyst is calcined under a protective atmosphere to obtain a carbon-modified silica intercalation-modified composite catalyst.

2. The method for preparing an acetate hydrogenation catalyst according to claim 1, wherein In step (1), the treatment agent A is one or more of diethanolamine, diisopropanolamine, triisopropanolamine, N,N-dimethylethanolamine, hexamethylenetetramine, acetamide, diphenylamine, and p-methylaniline, and the concentration of the treatment agent A is 0.5-5 wt% of the total mass of the mixed solution.

3. The method for preparing the acetate hydrogenation catalyst according to claim 1, wherein In step (1), the organic silicon source is at least one of methyl orthosilicate and ethyl orthosilicate, and its content is 0.1% to 3% of the total mass of the mixed solution.

4. The method for preparing an acetate hydrogenation catalyst according to claim 1, wherein In step (3), the treatment agent B is one or more of polyethylene glycol, OP-20, sodium stearate, and fatty acid polyethylene glycol ester, and its content is 0.5%-2% of the total mass of the dispersion solution.

5. The method for preparing the acetate hydrogenation catalyst according to claim 1, wherein In step (3), the auxiliary agent M is at least one of Zn and Zr; the auxiliary agent N is at least one of Mn, Fe, Co, Ni, Ce, La, and Mo.

6. The method for preparing an acetate hydrogenation catalyst according to claim 1, wherein In step (3), the molar ratio of the copper salt, the auxiliary agent M, and the auxiliary agent N is 1: (0.5-1.5): (0.01-0.08).

7. The method for preparing an acetate hydrogenation catalyst according to claim 1, wherein In step (3), the calcination temperature is 300-600°C, the calcination time is 3-8 hours, and the calcination atmosphere is either nitrogen or argon.

8. The acetate hydrogenation catalyst prepared by the preparation method according to claims 1 to 7, characterized in that: The invention comprises a carrier, an active component supported on the carrier, and an additive, wherein the active component is Cu, the carrier is a carbon-modified and silica-intercalated hydrotalcite-like carrier, and the additives are M and N. After reduction, the composition is as follows: 5 to 40 parts of Cu, 30 to 60 parts of Al, 0.1 to 2 parts of carbon, 0.5 to 5 parts of SiO2, 10 to 30 parts of additive M, and 1 to 5 parts of additive N.

9. Use of the acetate hydrogenation catalyst according to claim 8 in catalytic hydrogenation of methyl acetate to ethanol.

10. It is characterized in that The conditions for the catalytic hydrogenation include: a reaction temperature of 150-240° C., a reaction pressure of 1.0-3.0 MPa, an acetate space velocity of 0.5-3.0 g / hour, and a hydrogen-to-ester ratio of 2-100.

Images