Method and catalyst for preparing 2-ethylhexanol and application of 2-ethylhexanol and catalyst

Abstract

The invention relates to the technical field of preparation of 2-ethylhexanol, and discloses a method for preparing 2-ethylhexanol, a catalyst and application of the method and the catalyst. According to the method provided by the invention, hydrogenation of 2-ethylhexanal can be carried out at room temperature or near room temperature, and 2-ethylhexanol can be obtained with relatively high conversion rate and selectivity. Compared with the existing 2-ethylhexanal hydrogenation reaction, the method has the advantages that the reaction temperature is greatly reduced, on one hand, the energy consumption of the whole reaction is reduced, and on the other hand, the safety in the reaction process can be improved. Therefore, the method provided by the invention is suitable for large-scale application and popularization and has a relatively wide prospect.

Description

Technical Field

[0001] This invention relates to the field of 2-ethylhexanol preparation technology, and more specifically, to a method for preparing 2-ethylhexanol, a catalyst, and their applications. Background Technology

[0002] 2-Ethylhexanol is an important organic solvent and chemical intermediate with wide applications in materials, pharmaceuticals, and plasticizers. Industrially, 2-ethylhexanol is primarily prepared by hydrogenation of 2-ethylhexanal.

[0003] Currently, researchers in this field have developed different types of 2-ethylhexanol hydrogenation catalysts and corresponding hydrogenation reaction methods. For example, CN103894207A discloses a method for hydrogenating 2-ethylhexanal using a rare earth lanthanum-modified Ni-Cu-Mn-La / Al2O3 catalyst at a reaction temperature of 70-180℃; US4021497 discloses a method for preparing 2-ethylhexenal by hydrogenation using a Co-Ni-Cu-Mg catalyst, and adds P element to the catalyst support, with the catalyst operating at a temperature of 80-200℃; US4626604A discloses a continuous multi-stage aldehyde hydrogenation method, using a pre-reduced CuO-ZnO catalyst to hydrogenate 2-ethylhexenal to 2-ethylhexanol at a reaction temperature of 120-220℃; CN1511816A and CN1478596A respectively disclose methods for preparing 2-ethylhexanol using a nickel-supported alumina catalyst with alkali metal or alkaline earth metal as promoters, with hydrogenation temperatures of 80-260℃.

[0004] Therefore, the existing hydrogenation reaction of 2-ethylhexanal still requires a relatively high temperature, resulting in high energy consumption in the production process. Furthermore, the heated state may pose a safety hazard due to improper use of hydrogen. Therefore, there is an urgent need to develop a 2-ethylhexanal hydrogenation catalyst that exhibits high activity at lower reaction temperatures to reduce carbon emissions and improve production safety. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of high energy consumption and insufficient safety in the hydrogenation of 2-ethylhexanol due to the high temperature in the existing technology, and to provide a method for preparing 2-ethylhexanol, a catalyst, and their applications. The method provided by this invention can achieve high conversion and selectivity in the preparation of 2-ethylhexanol at a reaction temperature close to room temperature, reducing the energy consumption of the 2-ethylhexanol hydrogenation reaction and improving the reaction safety.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for preparing 2-ethylhexanol, the method comprising reacting 2-ethylhexanol and hydrogen in the presence of a nickel-based catalyst.

[0007] The nickel-based catalyst comprises alumina and nickel, wherein the nickel dispersion is not less than 10%, and the particle size distribution of the nickel-based catalyst is 10-50 nm.

[0008] The second aspect of the present invention provides a nickel-based catalyst used in the method described in the first aspect.

[0009] A third aspect of the present invention provides a method for preparing a nickel-based catalyst for the hydrogenation of 2-ethylhexanol, the method comprising contacting a nickel source and an aluminum source in liquid form in a rotational strengthening apparatus and crystallizing the contact product.

[0010] A fourth aspect of the present invention provides a nickel-based catalyst prepared according to the method described in the third aspect.

[0011] The fifth aspect of the present invention provides the application of the method described in the first aspect, and / or the catalyst described in the second or fourth aspect, and / or the method described in the third aspect, in reducing the temperature of the hydrogenation reaction of 2-ethylhexanal.

[0012] Through the above technical solution, the present invention can achieve at least the following beneficial effects:

[0013] (1) The method provided by the present invention has a high conversion rate of 2-ethylhexanal and a high selectivity of 2-ethylhexanol.

[0014] (2) The method provided by the present invention can be carried out at near room temperature, which significantly reduces the reaction temperature compared with the prior art, thereby reducing the reaction energy consumption and better meeting the needs of green and sustainable industrial production.

[0015] (3) The method provided by the present invention can reduce or even eliminate the external heating equipment for the hydrogenation reaction of 2-ethylhexanol, thereby reducing the investment in equipment reduction and maintenance, and has higher safety, making it suitable for large-scale production and promotion. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the rotational strengthening device used in the preparation of nickel-based catalysts according to the present invention.

[0017] Figure 2 These are SEM images of catalysts S1-5 and D1 obtained in Preparation Example 1.

[0018] Explanation of reference numerals in the attached figures

[0019] 1-1 First container; 1-2 Second container; 1-3 First liquid pump; 1-4 Second liquid pump; 1-5 Solution distributor; 1-6 Wire mesh packing; 1-7 Reactor shell; 1-8 Material outlet; 1-9 Crystallization kettle; 1-10 Motor. Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] In this invention, unless otherwise specified, "room temperature" refers to the normal indoor temperature, usually 20-30℃, and "near room temperature" refers to a temperature close to room temperature, which may be slightly higher than room temperature, for example, 30-50℃. In this invention, "room temperature and near room temperature" refers to a temperature range including room temperature and near room temperature, which can be 20-50℃.

[0022] During their research, the inventors of this invention ingeniously discovered that when using a nickel-based catalyst to catalyze the hydrogenation of 2-ethylhexanol, the reaction activity is largely influenced by the catalyst particle size (e.g., particle size, uniformity of particle size distribution, etc.) and the dispersion of nickel on the catalyst. When the catalyst particle size is small and relatively uniform, and the nickel dispersion on the catalyst reaches a certain level, the nickel-based catalyst not only exhibits high conversion and selectivity, but also unexpectedly lowers the hydrogenation temperature of 2-ethylhexanol, allowing the reaction to proceed at a lower temperature while maintaining high conversion and selectivity.

[0023] Based on this, the first aspect of the present invention provides a method for preparing 2-ethylhexanol, the method comprising reacting 2-ethylhexanol and hydrogen in the presence of a nickel-based catalyst.

[0024] The nickel-based catalyst comprises alumina and nickel, wherein the nickel dispersion is not less than 10%, and the particle size distribution of the nickel-based catalyst is 10-50 nm.

[0025] In this invention, "dispersion degree" is a characterizing parameter for the degree of nickel dispersion in the catalyst. Typically, the amount of hydrogen adsorbed by the catalyst can be detected using hydrogen chemisorption, and the Ni dispersion degree of the catalyst can be calculated using the following formula (Equation I).

[0026]

[0027] In Formula I, D% is the nickel dispersion of the catalyst to be tested (in %), and V ad M is the saturated adsorption capacity of the catalyst to be tested for hydrogen. Ni It is the molar mass of nickel, m ca t is the mass of the catalyst loaded during testing, and wt% is the nickel content in the catalyst to be tested.

[0028] "Catalyst particle size distribution" refers to the range of minimum and maximum measured catalyst particle sizes. Catalyst particle size is typically measured using methods such as SEM observation and laser particle size analyzer. The size of the particle size distribution range reflects both the overall particle size level and the uniformity of particle size (for example, catalysts with a smaller particle size distribution range generally exhibit better particle size uniformity than those with a larger distribution).

[0029] According to a preferred embodiment of the present invention, the nickel dispersion in the nickel-based catalyst is 10-20%, preferably 12-18%.

[0030] For example, in the nickel-based catalyst, the dispersion of nickel can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0031] According to a preferred embodiment of the present invention, the nickel-based catalyst has a particle size distribution of 10-40 nm.

[0032] Preferably, the average particle size of the nickel-based catalyst is no more than 45 nm, and more preferably 10-40 nm.

[0033] For example, the average particle size of the nickel-based catalyst can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, or 45nm, or it can be any range of any two of the above values, or any intermediate value in that range.

[0034] The average particle size of the catalyst can also indicate the particle size distribution characteristics of the catalyst particles to a certain extent. When the particle size distribution of the nickel-based catalyst meets the requirements of the present invention, its average particle size also meets the requirements of the present invention, which can further improve the conversion rate and selectivity when using the catalyst to prepare 2-ethylhexanol according to the method of the present invention.

[0035] Preferably, the nickel-based catalyst contains 30-80 wt.% nickel by weight of the total catalyst.

[0036] Preferably, in the nickel-based catalyst, the alumina content is 20-70 wt.% based on the total weight of the catalyst.

[0037] According to a preferred embodiment of the present invention, the temperature of the reaction does not exceed 70°C, and is preferably 20-60°C.

[0038] For example, the reaction temperature can be 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, or 70℃, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0039] Preferably, the reaction temperature can be 20-50℃ (this temperature can also be referred to as "room temperature and near room temperature" in this invention). When the hydrogenation reaction of 2-ethylhexanal is carried out in the above temperature range using the method of this invention, on the one hand, better reaction results can be achieved (i.e., the conversion rate and selectivity reach a high level), and on the other hand, heating can be reduced or even omitted, thereby reducing the energy consumption and carbon emissions of the reaction.

[0040] Preferably, the reaction conditions further include a pressure of 1-5 MPa.

[0041] Under specific temperature and pressure conditions, the method provided by this invention can achieve better reaction results at room temperature and near room temperature.

[0042] The second aspect of the present invention provides a nickel-based catalyst used in the method described in the first aspect.

[0043] A third aspect of the present invention provides a method for preparing a nickel-based catalyst for the hydrogenation of 2-ethylhexanol, the method comprising contacting a nickel source and an aluminum source in liquid form (i.e., in solution form) in a rotational strengthening apparatus and crystallizing the contact product.

[0044] According to a preferred embodiment of the present invention, the nickel source is provided by an aqueous solution of a water-soluble inorganic nickel salt, preferably the concentration of Ni in the aqueous solution of the water-soluble inorganic nickel salt is 0.1-3M (for example, it can be 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.35M, 0.4M, 0.45M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, 1.1M, 1.2M, 1.3M, 1.4M, 1.5M, 1.6M, 1.7M, 1.8M, 1.9M, 2M, 2.2M, 2.4M, 2.6M, 2.8M, 3M, or it can be a range consisting of any two of the above values, or any intermediate value in the range).

[0045] Preferably, the concentration of Ni in the aqueous solution of the water-soluble inorganic nickel salt is 0.1-2M.

[0046] Any water-soluble inorganic nickel salt can be used in the method provided by this invention. Preferably, the water-soluble inorganic nickel salt is nickel nitrate and / or nickel sulfate.

[0047] According to a preferred embodiment of the present invention, the aluminum source is provided by a mixed solution of an aluminum-containing compound, an inorganic basic compound, and a polymer containing nitrogen-containing heterocyclic side groups.

[0048] Preferably, the amounts of the aluminum-containing compound, inorganic base, and nitrogen-containing heterocyclic side-group polymer are such that the concentration of Al in the aluminum source is 0.01-1M, for example, 0.01M, 0.02M, 0.03M, 0.04M, 0.05M, 0.06M, 0.07M, 0.08M, 0.09M, 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.35M, 0.4M, 0.45M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, or any range consisting of any two of the above values, or any intermediate value within that range); the concentration of the inorganic base is 0.1-2M (for example, 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.35M, 0. The concentration of the nitrogen-containing heterocyclic side group polymer is 0.01-0.1M (e.g., 0.4M, 0.45M, 0.5M, 0.55M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, or any range of any two of the above values, or any intermediate value within that range);

[0049] More preferably, the concentration of Al in the aluminum source is 0.05-0.5 M, the concentration of the inorganic base is 0.1-1 M, and the concentration of the polymer containing nitrogen-containing heterocyclic side groups is 0.01-0.1 M.

[0050] Preferably, the aluminum-containing compound is selected from sodium aluminate and / or potassium aluminate.

[0051] Preferably, the inorganic alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0052] Preferably, the polymer containing nitrogen-containing heterocyclic side groups is polyvinylimidazole, and more preferably, the polyvinylimidazole has a weight-average molecular weight of 10. 3 -10 6 g / mol.

[0053] More preferably, the weight-average molecular weight of the polyvinylimidazole is 10. 4-10 5 g / mol. "10" 3 -10 6 "g / mol" refers to the weight-average molecular weight of the polyvinylimidazole used in this invention, which can be 10 g / mol. 3 -10 6 Within the g / mol level range. "10 3 "g / mol level" refers to a weight-average molecular weight on the order of 10. 3 For example, 1×10 3 g / mol, 5×10 3 g / mol, 9.9×10 3 g / mol and similar values ​​belong to "10". 3 "g / mol level". Therefore, the weight-average molecular weight of the polyvinylimidazole used in this invention can be greater than or equal to 1×10⁻⁶ g / mol. 3 g / mol to less than 1×10 7 Within the range of g / mol, preferably greater than or equal to 1×10 4 g / mol to less than 1×10 6 Within the range of g / mol.

[0054] For example, the weight-average molecular weight of the polyvinylimidazole can be 1 × 10⁻⁶. 3 g / mol, 5×10 3 g / mol, 9.9×10 3 g / mol, 1×10 4 g / mol, 2×10 4 g / mol, 3×10 4 g / mol, 4×10 4 g / mol, 5×10 4 g / mol, 6×10 4 g / mol, 7×10 4 g / mol, 8×10 4 g / mol, 9×10 4 g / mol, 9.9×10 4 g / mol, 1×10 5 g / mol, 2×10 5 g / mol, 3×10 5 g / mol, 4×10 5 g / mol, 5×10 5 g / mol, 6×10 5 g / mol, 7×10 5 g / mol, 8×10 5 g / mol, 9×10 5 g / mol, 9.9×10 5g / mol, 1×10 6 g / mol, 5×10 6 g / mol, 9.9×10 6 g / mol, or it can be any range of the two values ​​mentioned above, or any intermediate value within that range.

[0055] According to a preferred embodiment of the present invention, the rotational speed of the rotational strengthening device is not less than 500 rpm. Determining the lower limit of the rotational speed of the rotational strengthening device is crucial for obtaining the catalyst used in the method of the present invention. If the rotational speed is too low, insufficient shear force of the packing material will result in larger catalyst particles, failing to achieve the objectives of the present invention.

[0056] Preferably, the rotational speed of the rotational strengthening device is 500-3000 rpm (for example, it can be 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, 2000 rpm, 2200 rpm, 2400 rpm, 2600 rpm, 2800 rpm, 3000 rpm, or it can be a range consisting of any two of the above values, or any intermediate value in the range).

[0057] Preferably, the crystallization treatment temperature is 30-50℃ (e.g., 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, or any range of two of the above values, or any intermediate value within that range), and the time is 10-60 min (e.g., 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, or any range of two of the above values, or any intermediate value within that range). The catalyst obtained under the above crystallization treatment conditions can achieve better reaction results when used in the method of the present invention.

[0058] Preferably, the method further includes the steps of filtering, washing, and drying the crystallization product after the crystallization treatment is completed. The purpose of these steps is to filter out the solids (i.e., the obtained catalyst) from the crystallization product, remove the reaction system components remaining on its surface, and dry it to obtain a usable catalyst.

[0059] Furthermore, the present invention also provides an apparatus for preparing a nickel-based catalyst for the hydrogenation of 2-ethylhexanal. (Reference) Figure 1The device includes a reactor shell 1-7 and wire mesh packing 1-6 disposed inside the reactor shell 1-7 and a solution mixing distributor 1-5;

[0060] The reactor shell is provided with a solution inlet and a mixture outlet 1-8, and the solution inlet is connected to the solution mixing distributor 1-5.

[0061] Preferably, the nickel and aluminum sources in liquid form enter the solution distributor 1-5 through the solution inlet and are sprayed onto the high-speed rotating wire mesh packing 1-6 (the wire mesh packing 1-6 rotates at high speed under the drive of the motor 1-10, and the specific rotation speed is as described above), and the reaction takes place on the wire mesh.

[0062] The reaction suspension is collected from material outlet 1-8 and introduced into crystallization vessel 1-9 for crystallization treatment. Therefore, the apparatus preferably further includes crystallization vessel 1-9. More preferably, crystallization vessel 1-9 is connected to material outlet 1-8.

[0063] Preferably, the device may further include a first container 1-1 for storing a nickel source solution and a second container 1-2 for storing an aluminum source solution. The first container 1-1 and the second container 1-2 are connected to a solution inlet, and preferably, under the action of a first liquid pump 1-3 and a second liquid pump 1-4 respectively, the nickel source and the aluminum source enter the solution distributor 1-5 through the solution inlet.

[0064] A fourth aspect of the present invention provides a nickel-based catalyst prepared according to the method described in the third aspect.

[0065] The fifth aspect of the present invention provides the application of the method described in the first aspect, and / or the catalyst described in the second or fourth aspect, and / or the method described in the third aspect, in reducing the temperature of the hydrogenation reaction of 2-ethylhexanal.

[0066] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are only for illustrative purposes to further explain and illustrate the content of the present invention, and are not intended to limit the present invention.

[0067] Unless otherwise specified, all reagents and materials used in the following examples were commercially available products from reputable chemical reagent / material suppliers, and all reagents were of analytical grade. The polyvinylimidazole used in the following examples was purchased from Inocare, with a weight-average molecular weight of approximately 1 × 10⁻⁶. 4 -1×10 5 g / mol.

[0068] Preparation Example 1

[0069] This preparation example illustrates the preparation of the nickel-based catalyst used in this invention.

[0070] use Figure 1 The catalyst was prepared using the following method in the apparatus described in Table 1.

[0071] The first container 1-1 contains an aqueous solution of nickel nitrate, and the second container 1-2 contains an aqueous solution of sodium aluminate, sodium carbonate, and polyvinylimidazole. Driven by the first liquid pump 1-3 and the second liquid pump 1-4, the aqueous solution of nickel nitrate (i.e., the nickel source) and the aqueous solution of sodium aluminate, sodium carbonate, and polyvinylimidazole (i.e., the aluminum source) enter and contact with the solution distributor 1-5. The solution distributor 1-5 sprays the introduced nickel and aluminum source mixture into a rotating wire mesh packing. Driven by the motor 1-10, the wire mesh packing 1-6 rotates at high speed, and the sprayed liquid is sheared into tiny droplets by the wire mesh and mixed and reacted. Finally, the liquid is discharged from the reactor through the material outlet 1-8 at the bottom of the reactor and enters the connected crystallization tank 1-9 for crystallization treatment.

[0072] After crystallization, the solid material is filtered out, washed with deionized water, and then dried (80℃, 600 min) and calcined (300℃, 360 min) in sequence.

[0073] Table 1

[0074]

[0075] A control catalyst was prepared using a conventional co-precipitation method in a stirred tank reactor. The specific method is as follows: A 0.15 M nickel nitrate aqueous solution was prepared as the nickel source, and a mixture of sodium aluminate, sodium carbonate, and polyvinylimidazole at concentrations of 0.05 M, 0.1 M, and 0.01 M was prepared as the aluminum source. The prepared solutions were added dropwise to a stirred tank reactor at a volumetric flow rate of 1:1 (nickel source solution to aluminum source solution). The stirring speed was 400 rpm. The precipitate was transferred to a crystallization reactor and crystallized at 30 °C for 10 min. After filtration, washing with deionized water, and drying, the crystallized product yielded the conventional co-precipitation nickel-based catalyst, denoted as D1.

[0076] The nickel and alumina contents of the above nickel-based catalysts were determined by XRF testing.

[0077] The particle size and particle uniformity (reflected by particle size distribution and average particle size) of the above nickel-based catalysts were detected by SEM testing. Detailed SEM images of each catalyst can be found in [link to SEM image]. Figure 2 ;

[0078] The nickel dispersion of the above nickel-based catalyst was tested using the following method: A Micron Autochem 2920 instrument was used. The catalyst was treated at 500℃ for 2 hours in a pure hydrogen atmosphere, then purged with high-purity argon at 500℃ for 1 hour. The temperature was then lowered to 45℃, and high-purity hydrogen pulse adsorption was switched until adsorption saturation. Based on the test results, the nickel dispersion (D%) was calculated using the following formula:

[0079]

[0080] Where V ad M is the saturated adsorption capacity of hydrogen. Ni It is the molar mass of nickel, m ca t is the mass of the catalyst packed, and wt% is the nickel content in the catalyst.

[0081] For detailed test results, please refer to Table 2.

[0082] Table 2

[0083] serial number Ni content / wt.% Alumina content / wt.% Average particle size / nm Particle size distribution / nm Nickel dispersion / % S1 70 30 25 19-38 17.1 S2 71 29 24 16-34 15.0 S3 68 32 19 13-28 15.9 S4 71 29 21 15-30 14.3 S5 72 28 33 27-39 12.2 D1 70 30 48 22-75 10.2

[0084] Example 1

[0085] The nickel-based catalyst obtained in Preparation Example 1 was used to carry out the hydrogenation reaction of 2-ethylhexanal to prepare 2-ethylhexanol. The specific method is as follows:

[0086] Before reaction evaluation, each catalyst was reduced with hydrogen at 500℃ for 4 hours. Then, 2g, 5g, and 20g of the reduced catalyst, 2-ethylhexanal, and 2-ethylhexanol were weighed and added to a stainless steel reactor. The reactor was completely sealed, and the air inside was replaced three times with high-purity hydrogen. The reaction was carried out for 5 hours at the set reaction temperature and hydrogen pressure, with a stirring rate of 400 rpm. The obtained products were analyzed by gas chromatography with an FID detector. Based on the detection results, the maleic anhydride conversion and succinic anhydride selectivity were calculated using the following formula:

[0087]

[0088] The experimental results are shown in Table 3.

[0089] Table 3

[0090]

[0091] Comparing the test results in Table 3, it can be seen that when using the catalyst selected in this invention for the hydrogenation of maleic anhydride, high conversion and high selectivity of 2-ethylhexanol can be achieved at room temperature or (20-30℃). Furthermore, with specific reaction conditions, the conversion and selectivity can be further improved. Specifically, comparing the test results of catalyst S1 under different conditions shows that although the reaction temperature and pressure both affect the conversion and selectivity, generally, the preferred reaction conditions selected in this invention yield relatively ideal reaction results. Comparing the test results using catalysts S1-S5 with those using catalyst D1 shows that when using the catalyst with the characteristics described in this invention for the hydrogenation of 2-ethylhexanol, higher conversion and selectivity can be obtained compared to using traditional co-precipitation nickel-based catalysts.

[0092] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing 2-ethylhexanol, characterized in that, This method involves reacting 2-ethylhexanal and hydrogen in the presence of a nickel-based catalyst. The nickel-based catalyst comprises alumina and nickel, wherein the nickel dispersion is not less than 10%, and the particle size distribution of the nickel-based catalyst is 10-50 nm.

2. The method according to claim 1, wherein, In the nickel-based catalyst, the nickel dispersion is 10-20%, preferably 12-18%; And / or, the particle size distribution of the nickel-based catalyst is 10-40 nm; Preferably, the average particle size of the nickel-based catalyst is no more than 45 nm, and more preferably 10-40 nm; Preferably, the nickel-based catalyst contains 30-80 wt.% nickel by weight of the total catalyst. Preferably, in the nickel-based catalyst, the alumina content is 20-70 wt.% based on the total weight of the catalyst.

3. The method according to claim 1, wherein, The temperature of the reaction does not exceed 70°C, and is preferably 20-60°C; Preferably, the reaction conditions further include a pressure of 1-5 MPa.

4. The nickel-based catalyst used in the method of any one of claims 1-3.

5. A method for preparing a nickel-based catalyst for the hydrogenation of 2-ethylhexanol, characterized in that, The method involves contacting a nickel source and an aluminum source in liquid form within a rotational strengthening apparatus, and then crystallizing the contact product.

6. The method according to claim 5, wherein, The nickel source is provided by an aqueous solution of a water-soluble inorganic nickel salt, preferably with a Ni concentration of 0.1-3 M, more preferably 0.1-2 M; Preferably, the water-soluble inorganic nickel salt is nickel nitrate and / or nickel sulfate.

7. The method according to claim 5, wherein, The aluminum source is provided by a mixed solution of an aluminum-containing compound, an inorganic basic compound, and a polymer containing nitrogen heterocyclic side groups. Preferably, the amounts of the aluminum-containing compound, the inorganic base, and the polymer containing nitrogen heterocyclic side groups are such that the concentration of Al in the aluminum source is 0.01-1M, the concentration of the inorganic base is 0.1-2M, and the concentration of the polymer containing nitrogen heterocyclic side groups is 0.01-0.1M. Preferably, the aluminum-containing compound is selected from sodium aluminate and / or potassium aluminate; Preferably, the inorganic alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; Preferably, the polymer containing nitrogen-containing heterocyclic side groups is polyvinylimidazole, and more preferably, the polyvinylimidazole has a weight-average molecular weight of 10. 3 -10 6 g / mol.

8. The method according to claim 5, wherein, The rotational speed of the rotational strengthening device is not less than 500 rpm, preferably 500-3000 rpm; Preferably, the crystallization treatment temperature is 30-50℃ and the time is 10-60min. Preferably, the method further includes the steps of filtering, washing and drying the crystallization product after the crystallization treatment is completed.

9. The nickel-based catalyst prepared by any one of claims 5-8.

10. The method of any one of claims 1-3, and / or the catalyst of claim 4 or 8, and / or the method of any one of claims 5-7, in reducing the temperature of the hydrogenation reaction of 2-ethylhexanal.

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