Process for the preparation of aromatic alcohols by hydrogenation of aromatic aldehydes

Abstract

The present application provides a method for preparing aromatic alcohol by hydrogenation of aromatic aldehyde. The method of the present application comprises hydrogenation of aromatic aldehyde in the presence of copper tailing catalyst to obtain the corresponding aromatic alcohol; wherein the aromatic aldehyde is selected from one or more of aldehyde compounds containing benzene ring and aldehyde compounds containing furan ring; the copper tailing catalyst is prepared by a method comprising the following steps: drying and crushing the copper tailing through a sieve, and then calcining and reducing to obtain the copper tailing catalyst. The present application uses the treated copper tailing as a catalyst for hydrogenation of aromatic aldehyde, especially in the reaction of preparing furfuryl alcohol by hydrogenation of furfural, which has a very high selectivity of furfuryl alcohol, and realizes the resource utilization of copper tailing.

Description

Technical Field

[0001] This invention relates to the field of catalytic hydrogenation technology, specifically to a method for preparing aromatic alcohols by hydrogenation of aromatic aldehydes, and particularly to a method for preparing furfural alcohol by hydrogenation of furfural. Background Technology

[0002] Furfuryl alcohol is a colorless or pale yellow liquid that turns brown or dark red when exposed to sunlight and air. It has a distinctive bitter and pungent odor and is an important chemical intermediate. As an important and versatile organic chemical raw material, furfuryl alcohol can be effectively converted into various high-value chemicals, such as furfural resin, urea-formaldehyde resin, phenolic resin, fruit acids, plasticizers, and rocket fuel.

[0003] CN119368183A discloses a method for preparing flower-shaped nickel-aluminum oxide and its application in the catalytic transfer hydrogenation of furfural to prepare furfuryl alcohol. However, this process is relatively long, and glutaric acid is derived from petroleum-based raw materials, resulting in limited yield and high cost.

[0004] CN117181225A discloses a method for preparing a non-precious metal supported carbon catalyst and its application in the hydrogenation of furfural to furfuryl alcohol. A semi-polymerized glucose solution is thoroughly impregnated with a metal-organic framework under reduced pressure to obtain a complex. Excess semi-polymerized glucose is washed to remove it from the surface and the complex is thoroughly dried. The complex structure is stabilized by low-temperature pyrolysis, followed by a second high-temperature pyrolysis to obtain the catalyst. This catalyst suffers from the problem of secondary metal ion contamination due to the loss of active metal. The entire reaction process is complex, the catalyst raw materials are expensive, and the production cost is high.

[0005] CN117181239A discloses a method for preparing a copper-based catalyst and its application in the hydrogenation of furfural to furfuryl alcohol. The method involves using either wollastonite powder (SH) or calcium silicate powder (SG) as a support, a copper-palladium composite metal oxide as the active component, and ascorbic acid as a structure-directing agent, prepared via a hydrothermal synthesis method. Based on the mass of the support, the mass percentage of cuprous oxide is 15-40%, and the mass percentage of palladium oxide is 0.1-1.0%. This catalyst exhibits low activity, a complex preparation method, and instability, leading to incomplete reaction of the reactants.

[0006] CN113292520A discloses a method for the catalytic hydrogenation of furfural to prepare furfuryl alcohol and its magnetic catalyst. This magnetic catalyst is a supported catalyst, with its active component Co derived from a corresponding non-noble metal salt solution. The catalyst support is an oxide selected from Al or Nb oxides. The catalyst is prepared using a simple excess impregnation method, with the loading of the active component being 20% ​​of the corresponding support mass. The method uses furfural, a biomass hydrolysis product, as raw material, commercial hydrogen as the hydrogen source, and deionized water as the solvent. The reaction is carried out at a temperature of 100-140℃, a hydrogen pressure of 1-2 MPa, a stirring speed of 400 rpm, and a reaction time of 1-4 h. Although it exhibits high furfural conversion and furfuryl alcohol selectivity, the catalyst preparation method is complex, the catalyst dispersion is uneven, and the price is high.

[0007] CN117160457A discloses a method for preparing a catalyst for furfuryl alcohol and its application. The catalyst is prepared by co-precipitation, using zirconium hydroxide (Zr(OH)4) as the active component and magnetic iron tetroxide (Fe3O4) as the support, and is synthesized with the assistance of a surfactant. This preparation process is demanding and complex, making large-scale development difficult.

[0008] Therefore, developing a non-precious metal catalyst for the one-step hydrogenation of furfural to furfuryl alcohol that is low in cost, high in yield, and stable is a current research challenge and has great economic benefits and industrial application value. Summary of the Invention

[0009] To address one of the aforementioned technical problems in the prior art, this invention provides a method for preparing aromatic alcohols by hydrogenation of aromatic aldehydes. Copper tailings are powdery solid waste remaining after copper ore is crushed and sorted, and their main components are silicates, oxides, and trace heavy metals. The inventors of this application have unexpectedly discovered that, after appropriate treatment, copper tailings can be used to catalyze the hydrogenation reaction of aromatic aldehydes, particularly in the hydrogenation of furfural to furfuryl alcohol, exhibiting high furfural conversion rate and furfuryl alcohol selectivity.

[0010] The method for preparing aromatic alcohols by hydrogenation of aromatic aldehydes provided by this invention includes the following steps:

[0011] Aromatic aldehydes are hydrogenated in the presence of a copper tailings catalyst to obtain the corresponding aromatic alcohols; wherein the aromatic aldehydes are selected from one or more aldehyde compounds containing benzene rings and aldehyde compounds containing furan rings; the copper tailings catalyst is prepared by a method comprising the following steps: drying and crushing copper tailings and sieving them, followed by calcination and reduction to obtain the copper tailings catalyst.

[0012] According to some embodiments of the present invention, the aromatic aldehyde is selected from one or more of furfural, 5-hydroxymethylfurfural, 5-methylfurfural, benzaldehyde, and cinnamaldehyde.

[0013] According to some embodiments of the present invention, the aromatic aldehyde is selected from furfural and benzaldehyde.

[0014] According to some embodiments of the present invention, the aromatic aldehyde is furfural, and the aromatic alcohol is furfuryl alcohol. In some embodiments, the furfural is furfural derived from renewable biomass resources.

[0015] According to some embodiments of the present invention, the aromatic aldehyde is benzaldehyde and the aromatic alcohol is benzyl alcohol.

[0016] According to some embodiments of the present invention, the copper tailings catalyst comprises Cu 0.05-0.2wt%, Zn 0.05-0.2wt%, MgO 1-5wt%, Fe2O3 8-15wt%, Al2O3 4-10wt%, and SiO2 60-75wt%.

[0017] According to some embodiments of the present invention, the copper tailings catalyst further includes one or more of Na2O, K2O, CaO, and TiO2.

[0018] According to some embodiments of the present invention, the copper tailings catalyst comprises Na2O 0.1-1.0wt%, MgO 1-5wt%, Al2O3 4-10wt%, SiO2 60-75wt%, K2O 0.1-1.0wt%, CaO 0.1-1.0wt%, Fe2O3 8-15wt%, TiO2 0.1-0.5wt%, Cu 0.05-0.2wt%, and Zn 0.05-0.2wt%.

[0019] According to some embodiments of the present invention, the copper tailings catalyst comprises 0.3-0.8 wt% Na2O, 2-5 wt% MgO, 5-8 wt% Al2O3, 65-70 wt% SiO2, 0.3-0.8 wt% K2O, 0.5-1.0 wt% CaO, 10-15 wt% Fe2O3, 0.1-0.5 wt% TiO2, 0.1-0.2 wt% Cu, and 0.1-0.2 wt% Zn.

[0020] According to some embodiments of the present invention, the copper tailings catalyst further includes other metallic elements selected from one or more of Sr, V, Cr, Ba, Rb, Ni, and Zr. In some embodiments, the mass content of the other metallic elements in the copper tailings catalyst is 10 ppm to 3000 ppm.

[0021] According to some embodiments of the present invention, the copper tailings catalyst comprises Na₂O 0.1-1.0 wt%, MgO 1-5 wt%, Al₂O₃ 4-10 wt%, SiO₂ 60-75 wt%, P₂O₅ 0.01-0.1 wt%, K₂O 0.1-1.0 wt%, CaO 0.1-1.0 wt%, MnO 0.01-0.1 wt%, Fe₂O₃ 8-15 wt%, TiO₂ 0.1-0.5 wt%, Ba 0.01-0.1 wt%, Cu 0.05-0.2 wt%, and Zn 0.05-0.2 wt%.

[0022] According to some embodiments of the present invention, the XRD pattern of the copper tailings catalyst is consistent with... Figure 1 Basically the same.

[0023] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the drying temperature is 90-150°C, preferably 100-120°C.

[0024] According to some embodiments of the present invention, in the preparation method of the copper tailings catalyst, the material is crushed through an 80-100 mesh sieve.

[0025] According to some embodiments of the present invention, in the preparation method of the copper tailings catalyst, the calcination temperature is 350-450℃, for example 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, etc.

[0026] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the calcination is carried out in air.

[0027] According to some embodiments of the present invention, in the preparation method of the copper tailings catalyst, the calcination time is 3-5 hours.

[0028] According to some embodiments of the present invention, in the preparation method of the copper tailings catalyst, the reduction temperature is 300-400℃, for example 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, etc.

[0029] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the reducing agent used in the reduction is hydrogen.

[0030] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the reduction is carried out in an inert atmosphere, such as an argon atmosphere.

[0031] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the reduction is carried out in a mixture of hydrogen and argon.

[0032] According to some embodiments of the present invention, in the method for preparing the copper tailings catalyst, the reduction time is 4-8 hours.

[0033] According to some embodiments of the present invention, the amount of the copper tailings catalyst is 3-10 times the mass of the aromatic aldehyde, for example, 3 times, 4 times, 4.5 times, 5 times, 5.5 times, 6 times, 6.5 times, 7 times, 8 times, 9 times, or 10 times. In some embodiments, the amount of the copper tailings catalyst is 4-7 times the mass of the aromatic aldehyde. In some embodiments, the amount of the copper tailings catalyst is 4.5-6.5 times the mass of the aromatic aldehyde. In some embodiments, the amount of the copper tailings catalyst is 5-5.5 times the mass of the aromatic aldehyde.

[0034] According to some embodiments of the present invention, the hydrogenation reaction is carried out in a C3-C6 alcohol solvent, such as isopropanol. In some embodiments, the volume ratio of the alcohol solvent to the mass of the aromatic aldehyde is (0.07-0.25) mL:1g, for example, 0.07 mL:1g, 0.08 mL:1g, 0.1 mL:1g, 0.12 mL:1g, 0.15 mL:1g, 0.18 mL:1g, 0.2 mL:1g, 0.22 mL:1g, 0.25 mL:1g, etc. In some embodiments, the furfural concentration in the solution formed by the furfural and the alcohol solvent is 1-30 wt.%, for example, 1 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%.

[0035] According to some embodiments of the present invention, the temperature of the hydrogenation reaction is 150-210°C, for example, 150°C, 170°C, 190°C, 195°C, 198°C, 200°C, 203°C, 205°C, 210°C, etc. In some embodiments, the temperature of the hydrogenation reaction is 190-210°C. In some embodiments, the temperature of the hydrogenation reaction is 195-205°C. In some embodiments, the temperature of the hydrogenation reaction is 198-203°C.

[0036] According to some embodiments of the present invention, the pressure of the hydrogenation reaction is 1-3.5 MPa, for example, 1 MPa, 1.5 MPa, 1.8 MPa, 2.0 MPa, 2.2 MPa, 2.5 MPa, 2.8 MPa, 3.0 MPa, 3.2 MPa, 3.5 MPa, etc. In some embodiments, the pressure of the hydrogenation reaction is 2-3.5 MPa. In some embodiments, the pressure of the hydrogenation reaction is 3-3.5 MPa.

[0037] According to some embodiments of the present invention, the hydrogenation reaction time is 12-96 hours, for example, 12 hours, 15 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, 78 hours, 84 hours, 90 hours, 96 hours, etc. In some embodiments, the hydrogenation reaction time is 60-84 hours. In some embodiments, the hydrogenation reaction time is 66-78 hours.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The method of the present invention uses copper tailings as hydrogenation catalyst after calcination and reduction treatment. The tailings contain a variety of metal elements, which will generate a large number of oxygen vacancies, enhance the adsorption and dissociation of oxygen, and the temperature required for each metal to break free and combine with adjacent metal particles is higher, thereby inhibiting agglomeration. It has high hydrogenation activity and excellent catalytic activity in the hydrogenation reaction of aromatic aldehydes. In particular, in the reaction of furfural hydrogenation to furfuryl alcohol, the furfural conversion rate can reach more than 98%, and the selectivity of furfuryl alcohol can reach more than 80%.

[0040] (2) The hydrogenation catalyst used in the method of the present invention is widely available, inexpensive, simple to prepare, has good recycling performance, and is green and environmentally friendly. Under relatively mild conditions, furfural is converted into furfuryl alcohol, a high-value-added chemical, realizing waste utilization and enabling large-scale industrial production. Attached Figure Description

[0041] Figure 1 The XRD pattern of the copper tailings catalyst obtained in the preparation example is shown.

[0042] Figure 2 The recycling performance of the copper tailings catalyst obtained in the preparation example in the hydrogenation of furfural to furfuryl alcohol is shown. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0044] Unless otherwise specified, all reagents used in the following experiments of this invention are conventional reagents; all raw materials, instruments and equipment used in the following experiments can be obtained by purchasing them from the market or by existing methods; unless otherwise specified, the reagent dosages are the dosages used in conventional experimental operations; unless otherwise specified, all experimental methods are conventional methods.

[0045] In the following test examples of this invention, gas chromatography was used to quantitatively test the content of each component in the product after the reaction.

[0046] The copper tailings used in this invention were collected from the copper system tailings of the second tailings dam of the Baiyin Nonferrous Metals Company's concentrator. The concentrator is located at No. 102 Yinshan Road, Baiyin District, Baiyin City, Gansu Province, and the second tailings dam is located in Dawanggou, Haojiachuan, in the eastern part of Baiyin City.

[0047] Preparation example: Preparation of copper tailings catalyst

[0048] The copper tailings were kept in an oven at 120℃ for 24 hours; then ground in a pollution-free ceramic rod mill jar, sieved through a 100-mesh sieve, calcined in air at 400℃ for 4 hours, and reduced with Ar-H2 at 350℃ for 6 hours to obtain the copper tailings catalyst (XRD characterization results are shown below). Figure 1 (As shown).

[0049] The elemental analysis results of the copper tailings catalyst based on X-ray fluorescence spectrometry (XRF) are shown in Table 1.

[0050] Table 1

[0051]

[0052] Test Example 1

[0053] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0054] A high-pressure reactor was used with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed amount was 1 mmol (96 mg), the catalyst amount was 500 mg, the reaction pressure was 3 MPa, the reaction temperature was 200 °C, and the solvent was 10 mL of isopropanol. The hydrogenation catalytic effect at different reaction times was investigated. The specific experimental parameters and reaction yields are shown in Table 2.

[0055] Table 2. Hydrogenation catalytic effect at different reaction times

[0056]

[0057] Note: "Other" in Table 2 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0058] As can be seen from Table 2 above, after 72 hours of reaction, both furfural conversion rate and furfuryl alcohol selectivity are at a high level. Further extending the reaction time will decrease both furfural conversion rate and furfuryl alcohol selectivity.

[0059] Test Example 2

[0060] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0061] A high-pressure reactor was used with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed amount was 1 mmol (96 mg), the catalyst amount was 500 mg, the reaction time was 72 h, the reaction temperature was 200 °C, and the solvent was 10 mL of isopropanol. The hydrogenation catalytic effect under different reaction pressures was investigated. The specific experimental parameters and reaction yields are shown in Table 3.

[0062] Table 3. Catalytic effect of hydrogenation under different reaction pressures

[0063]

[0064] Note: "Other" in Table 3 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0065] As can be seen from Table 3 above, the conversion rate of furfural and the selectivity of furfuryl alcohol are both high when the reaction pressure is between 1 and 3.5 MPa. Among them, the hydrogenation to furfuryl alcohol is most effective at 3 MPa.

[0066] Test Example 3

[0067] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0068] A high-pressure reactor was used with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed amount was 1 mmol (96 mg), the catalyst amount was 500 mg, the reaction time was 72 h, the reaction pressure was 3 MPa, and the solvent was 10 mL of isopropanol. The hydrogenation catalytic effect at different reaction temperatures was investigated. The specific experimental parameters and reaction yields are shown in Table 4.

[0069] Table 4. Hydrogenation catalytic effect at different reaction temperatures

[0070]

[0071] Note: "Other" in Table 4 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0072] As can be seen from Table 4 above, the furfural conversion rate and furfuryl alcohol selectivity are highest at a reaction temperature of 200℃. Temperatures that are too high or too low are not conducive to the formation of furfuryl alcohol.

[0073] Test Example 4

[0074] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0075] A high-pressure reactor was used with furfural and hydrogen as raw materials. The solvents are shown in Table 5. The furfural feed amount was 1 mmol (96 mg), the catalyst amount was 500 mg, the reaction time was 72 h, the reaction pressure was 3 MPa, and the reaction temperature was 200 °C. The effects of different types of solvents on the hydrogenation catalytic effect were investigated. The specific experimental parameters and reaction yields are shown in Table 5.

[0076] Table 5. Effect of different reaction solvents on hydrogenation catalytic efficiency

[0077]

[0078] Note: "Other" in Table 5 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0079] As can be seen from Table 5 above, compared with methanol, ethanol, tetrahydrofuran and toluene, furfural conversion and furfural selectivity are highest when isopropanol is used as the reaction solvent.

[0080] Test Example 5

[0081] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0082] A high-pressure reactor was used with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed rate was 1 mmol (96 mg), the solvent was 10 mL of isopropanol, the reaction time was 72 h, the reaction pressure was 3 MPa, and the reaction temperature was 200 °C. The hydrogenation catalytic effect under different catalyst dosages was investigated. Specific experimental parameters and reaction yields are shown in Table 6.

[0083] Table 6. Effect of different catalyst dosages on catalytic efficiency

[0084]

[0085] Note: "Other" in Table 6 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0086] As can be seen from Table 6 above, furfuryl alcohol exhibits the highest selectivity when the catalyst dosage is 500 mg.

[0087] Test Example 6

[0088] The catalytic performance of the copper tailings catalyst obtained in the preparation example was evaluated.

[0089] A high-pressure reactor was used with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed amount was 1 mmol (96 mg), the solvent was 10 mL of isopropanol, the reaction time was 72 h, the reaction pressure was 3 MPa, and the reaction temperature was 200 °C. The effect of different solvent amounts on the hydrogenation catalytic effect was investigated. Specific experimental parameters and reaction yields are shown in Table 7.

[0090] Table 7 Effect of different solvent dosages on catalytic effect

[0091]

[0092] Note: "Other" in Table 7 includes other reaction products besides those listed in the table, such as methanol, etc. Overall, the material balance is maintained.

[0093] As can be seen from Table 7 above, when the solvent volume is 10 mL and 15 mL, not only is the furfural conversion rate very high, but the furfuryl alcohol selectivity is also high.

[0094] Test Example 7

[0095] Examples 4 and 26-30 used different substrates to verify the catalytic performance of the copper tailings catalysts obtained in the preparation examples:

[0096] A high-pressure reactor was used, isopropanol was used as the solvent, and the substrate dosage was 1 mmol for all reactions. The catalyst dosage was 500 mg for all reactions, the solvent isopropanol 10 mL for all reactions, the reaction time was 72 h for all reactions, the reaction pressure was 3 MPa for all reactions, and the reaction temperature was 200 °C for all reactions. Specific experimental parameters and reaction yields are shown in Tables 8 to 13.

[0097] Table 8 Catalytic effect of catalyst on furfural

[0098]

[0099] Table 9 Catalytic effect of the catalyst on 5-hydroxymethylfurfural

[0100]

[0101] Table 10 Catalytic effect of catalyst on cinnamaldehyde

[0102]

[0103] Table 11 Catalytic effect of catalysts on benzaldehyde

[0104]

[0105] Table 12 Catalytic effect of catalyst on 5-methylfurfural

[0106]

[0107] Table 13 Catalytic effect of catalyst on 5-nitrofurfural

[0108]

[0109] Note: In Tables 8-13, "Other" includes other reaction products besides those listed in the tables, and the overall material balance is maintained.

[0110] As can be seen from Tables 8 to 13 above, compared with the hydrogenation reactions of 5-hydroxymethylfurfural, cinnamaldehyde, 5-methylfurfural and 5-nitrofurfural, the copper tailings catalyst prepared in this application not only has a high conversion rate of furfural and benzaldehyde in the hydrogenation reactions of furfural to furfuryl alcohol and benzaldehyde to benzyl alcohol, but also has a high selectivity for furfuryl alcohol and benzyl alcohol.

[0111] Test Example 8

[0112] The copper tailings catalyst (CTC) obtained in the preparation example was compounded with different types of metals to obtain different types of composite catalysts, and their catalytic performance was evaluated:

[0113] A high-pressure reactor was used, with furfural and hydrogen as raw materials and isopropanol as solvent. The furfural feed amount was 1 mmol (96 mg), the catalyst amount was 500 mg, the solvent is 10 mL of isopropanol, the reaction time was 72 h, the reaction pressure was 3 MPa, and the reaction temperature was 200 °C. Specific experimental parameters and reaction yields are shown in Table 14.

[0114] Table 14 Effects of different types of composite copper tailings catalysts on biomass furfural catalysis

[0115]

[0116] Note: In Table 14, "4%Ni-CTC" means that the doping mass of Ni in CTC is 4%; "Other" includes other reaction products besides those listed in the table, such as methanol, etc., and the overall material balance is maintained.

[0117] As can be seen from Table 14 above, the copper tailings catalyst (CTC) prepared in this application has a high furfural conversion rate and furfural selectivity in the reaction of furfural hydrogenation to furfural alcohol. However, the furfural selectivity decreases when CTC is compounded with metals such as Ni, Cu, Zn, Co or Fe.

[0118] Test Example 9: Catalyst Cyclic Performance Test

[0119] In Example 4, the catalyst was separated from the reaction system by centrifugation. The recovered catalyst was washed three times alternately with deionized water and ethanol, dried at 40°C for 12 hours, and then added to the next reaction. The recycling performance of the catalyst in the hydrogenation of furfural to furfuryl alcohol is as follows: Figure 2As shown in the figure. The results indicate that the catalyst prepared in the preparation example maintained good catalytic activity after being reused five times in the reaction of furfural hydrogenation to furfuryl alcohol, demonstrating good reproducibility.

[0120] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing aromatic alcohols by hydrogenation of aromatic aldehydes, characterized in that, Includes the following steps: Aromatic aldehydes are hydrogenated in the presence of a copper tailings catalyst to obtain the corresponding aromatic alcohols. The aromatic aldehyde is selected from one or more aldehyde compounds containing benzene rings and aldehyde compounds containing furan rings; the copper tailings catalyst is prepared by a method including the following steps: drying and crushing copper tailings and sieving them, and then calcining and reducing them to obtain the copper tailings catalyst. The copper tailings catalyst comprises Cu 0.05-0.2wt%, Zn 0.05-0.2wt%, MgO 1-5wt%, Fe2O3 8-15wt%, Al2O3 4-10wt%, and SiO2 60-75wt%.

2. The method according to claim 1, characterized in that, The aromatic aldehyde is selected from one or more of furfural, 5-hydroxymethylfurfural, 5-methylfurfural, benzaldehyde, and cinnamaldehyde.

3. The method according to claim 1, characterized in that, The copper tailings catalyst comprises Na2O 0.1-1.0wt%, MgO 1-5wt%, Al2O3 4-10wt%, SiO2 60-75wt%, K2O 0.1-1.0wt%, CaO 0.1-1.0wt%, Fe2O3 8-15wt%, TiO2 0.1-0.5wt%, Cu 0.05-0.2wt%, and Zn 0.05-0.2wt%.

4. The method according to any one of claims 1-3, characterized in that, The copper tailings catalyst also includes other metallic elements, which are selected from one or more of Sr, V, Cr, Ba, Rb, Ni, and Zr, and the mass content of the other metallic elements in the copper tailings catalyst is 10ppm-3000ppm.

5. The method according to claim 1, characterized in that, The calcination temperature is 350-450℃; and / or, the calcination is carried out in air; and / or, the calcination time is 3-5 hours; and / or, the reduction temperature is 300-400℃; and / or, the reducing agent used in the reduction is hydrogen; and / or, the reduction time is 4-8 hours; and / or, the reduction is carried out in an inert atmosphere.

6. The method according to any one of claims 1-3, characterized in that, The amount of the copper tailings catalyst is 3-10 times the mass of the aromatic aldehyde; and / or the hydrogenation reaction is carried out in a C3-C6 alcohol solvent.

7. The method according to claim 6, characterized in that, The amount of the copper tailings catalyst is 4-7 times the mass of the aromatic aldehyde; and / or the alcohol solvent includes isopropanol; and / or the volume ratio of the alcohol solvent to the mass of the aromatic aldehyde is (0.07-0.25) mL:1 mg.

8. The method according to any one of claims 1-3, characterized in that, The hydrogenation reaction is carried out at a temperature of 150-210°C; and / or at a pressure of 1-3.5 MPa; and / or for a time of 12-96 h.

9. The method according to claim 8, characterized in that, The hydrogenation reaction is carried out at a temperature of 195-205°C; and / or at a pressure of 3-3.5 MPa; and / or for a time of 66-78 h.

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