Method for preparing octenol by hydrogenation of octenal

Abstract

The invention relates to the technical field of octenol preparation, and discloses a method for preparing octenol by hydrogenation of octenal, which comprises the following steps: in the presence of hydrogen and a catalyst, reacting octenal with an inert solvent to obtain octenol, the catalyst comprises a carrier, an active component and an auxiliary agent, the active component and the auxiliary agent are loaded on the carrier, the carrier is alumina microspheres, the alumina microspheres are delta-Al2O3 and / or theta-Al2O3, the pore size distribution of the alumina microspheres is 15-45 nm, and the content of sulfur in the alumina microspheres is 0.01-0.2 wt%; the active component is copper, and the dispersity of the copper in the supported catalyst is 4.5-6%; by adopting the supported catalyst provided by the invention, the conversion rate of octenal and the yield of octenol can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of octenol preparation technology, and more specifically, to a method for preparing octenol from octenal by hydrogenation. Background Technology

[0002] 2-Ethyl-2-hexenol (abbreviated as octenol) is an important biopherin and organic intermediate with broad application markets in medicine, pesticides, and daily chemicals. The process route for preparing octenol from 2-ethyl-2-hexenal (abbreviated as octenal) has advantages such as high atom utilization, low environmental risk, and simple post-processing, and has become the mainstream design concept for the green industrial production of octenol. However, the activation energy required for hydrogenation of the C=O bond of octenal (approximately 40 kJ·mol⁻¹) is significant. -1 ) higher than C=C bond (approximately 35 kJ·mol) -1 The former is thermodynamically more disadvantageous. Therefore, achieving selective hydrogenation of the C=O bond in octenal is a key process step in the preparation of octenol.

[0003] Current industrial production methods largely employ homogeneous catalytic systems to achieve the selective hydrogenation of the C=O bond in octenal. For example, CN103288597B discloses a rhodium-bisphosphine ligand catalyst for the selective reduction of octenal using NaBH4, achieving an octenal yield of up to 85%. Furthermore, CN103857468B discloses a series of ruthenium / bidentate ligand complex catalysts, which can utilize H2 as a hydrogen source to achieve the selective hydrogenation of the C4-C bond. 19 Selective hydrogenation of unsaturated aldehydes and ketones is a crucial area of ​​research. However, homogeneous catalytic systems face challenges such as high catalyst production costs, short cycle life, and difficulties in separation. In recent years, the development of highly selective supported catalysts has become a key focus in this field.

[0004] CN109311789B discloses a method for preparing various α,β-unsaturated alcohols using an activated carbon-supported ruthenium-iron catalyst and a tertiary amine promoter. This catalyst achieves high substrate conversion and selectivity for unsaturated alcohols, but its precious metal raw material is costly, its active metal sites are easily lost, and its preparation process generates a large amount of wastewater. Furthermore, the tertiary amine promoter further increases separation costs and environmental risks.

[0005] CN114433103B discloses a method for selectively preparing octanal or octenol from octenal. In this method, the catalyst uses non-noble metals such as Cu, Ni, and Co as the active component, and further enhances its catalytic performance using alkaline earth metals such as Mg and Ba, and rare earth metals such as La and Ce. Although the catalyst exhibits high economic efficiency and catalytic activity, the selectivity for octenol is low, making it difficult to meet the demands of industrial production.

[0006] Therefore, developing novel selective hydrogenation catalysts that are rich in raw material resources, have simple preparation processes, and are both economical and environmentally friendly, and optimizing the process route for the preparation of octenol from octenal, remains one of the key issues that urgently need to be addressed in this field. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing octenol preparation processes, which struggle to balance economic efficiency and catalytic performance, and to provide a method for preparing octenol from octenal hydrogenation. The supported catalyst of this invention maintains a large pore volume at high temperatures and exhibits high dispersion of the active component. Using this supported catalyst can significantly improve the conversion rate of octenal and the yield of octenol. Furthermore, the raw materials for preparing this supported catalyst are abundant, the process is simple, and the catalyst preparation cost can be effectively reduced.

[0008] To achieve the above objectives, the present invention provides a method for preparing octenol from octenal hydrogenation. The method comprises: reacting octenal with an inert solvent in the presence of hydrogen and a catalyst to obtain octenol; wherein the catalyst is a supported catalyst, comprising a support and an active component and an auxiliary agent supported on the support, wherein the support is alumina microspheres, the sulfur content of the alumina microspheres is 0.01-0.2 wt%, the alumina microspheres are δ-Al₂O₃ and / or θ-Al₂O₃, and the pore size distribution of the alumina microspheres is between 15-45 nm; the active component is copper, and the copper dispersion in the supported catalyst is 4.5-6%.

[0009] Through the above technical solution, the present invention has the following beneficial effects:

[0010] (1) The sheet-like microstructure of the alumina microsphere carrier in this invention has an anchoring effect on active metal atoms. When the active metal loading is high, it can effectively suppress metal aggregation and improve the dispersion of active metal.

[0011] (2) The alumina microsphere support in this invention has a layered stacked structure with high water absorption, and a high metal loading catalyst can be prepared with a single impregnation, while conventional supports require three to four impregnation processes. Therefore, using the alumina microsphere support in this invention can effectively simplify the catalyst preparation process and reduce losses.

[0012] (3) This invention combines the preparation and molding of the carrier, achieving carrier molding without the need for secondary molding. Furthermore, the carrier preparation process uses trioctylamine as a solvent, which facilitates pore expansion, thus aiding in secondary pore expansion.

[0013] (4) Unlike existing alumina support preparation technology with large specific surface area, the alumina microsphere support in this invention can maintain a macroporous structure at high temperature, significantly reduce sulfur content, and has a crystal phase of δ-Al2O3 and / or θ-Al2O3 with moderate surface acidity, which helps to improve the catalytic activity of the supported catalyst for octenal hydrogenation. Detailed Implementation

[0014] 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.

[0015] As previously stated, this invention provides a method for preparing octenol from octenal hydrogenation. The method comprises: reacting octenal with an inert solvent in the presence of hydrogen and a catalyst to obtain octenol; wherein the catalyst is a supported catalyst, comprising a support and an active component and an auxiliary agent supported on the support, wherein the support is alumina microspheres, the sulfur content of the alumina microspheres is 0.01-0.2 wt%, the alumina microspheres are δ-Al₂O₃ and / or θ-Al₂O₃, and the pore size distribution of the alumina microspheres is between 15-45 nm; the active component is copper, and the copper dispersion in the supported catalyst is 4.5-6%.

[0016] The inventors of this invention have discovered that the alumina microsphere support used in this invention has a sheet-like microstructure, which anchors active metal atoms. When the active metal loading is high, it can effectively suppress metal aggregation and improve the dispersion of the active metal. Furthermore, unlike existing alumina support preparation techniques with large specific surface areas, the alumina microsphere support in this invention can maintain a macroporous structure at high temperatures, significantly reducing sulfur content. The alumina microspheres are δ-Al₂O₃ and / or θ-Al₂O₃, with moderate surface acidity, which helps improve the catalytic activity of the supported catalyst for the hydrogenation of octenal. In addition, the small interparticle gaps of this supported catalyst reduce the likelihood of localized hot spots during the reaction. Therefore, this supported catalyst can significantly improve the conversion rate of octenal and the yield of octenol.

[0017] According to the present invention, in a preferred embodiment, the copper dispersion in the supported catalyst is 4.6-5.6%, preferably 5-5.6%.

[0018] According to the present invention, the alumina microspheres have a layered stacked structure.

[0019] According to the present invention, the alumina microspheres are δ-Al2O3 and / or θ-Al2O3.

[0020] According to the present invention, the sulfur content in the alumina microspheres is 0.05-0.15 wt%, more preferably 0.08-0.15 wt%.

[0021] According to the present invention, the alumina microspheres have a particle diameter of 200-800 μm and a coefficient of variation of 3-8%; preferably, the alumina microspheres have a particle diameter of 500-800 μm and a coefficient of variation of 5-8%.

[0022] According to the present invention, the pore size distribution of the alumina microspheres is between 15-45 nm, preferably between 18-40 nm.

[0023] According to the present invention, the specific surface area of ​​the alumina microspheres is 80-150 m² / g, and the pore volume is 0.3-1.5 mL / g; preferably, the specific surface area of ​​the alumina microspheres is 86-140 m² / g, and the pore volume is 0.5-1.2 mL / g.

[0024] According to the present invention, the water absorption rate of the alumina microspheres is 150-250%, preferably 170-195%.

[0025] According to the present invention, the alumina microsphere carrier is prepared by the following steps:

[0026] (1) Prepare a sodium aluminate solution by mixing sodium hydroxide and sodium aluminate;

[0027] (2) Sodium aluminate solution was added dropwise to aluminum sulfate solution to obtain a dispersion of boehmite precursor;

[0028] (3) Using the dispersion of boehmite precursor as the dispersed phase and an organic solvent as the continuous phase, the dispersed phase is formed into droplets under the shearing action of the continuous phase, and gel microspheres are obtained after solidification and drying.

[0029] (4) The boehmite microspheres are then calcined to obtain alumina microspheres.

[0030] In the method for preparing alumina microspheres according to the present invention, in step (1), the molar ratio of sodium to aluminum in the sodium aluminate solution is (3-6):1.

[0031] According to the present invention, in step (1), the concentration of aluminum ions in the sodium aluminate solution is 0.1-1.0 mol / L.

[0032] According to the present invention, in step (2), the concentration of the aluminum sulfate solution is 0.1-1.0 mol / L.

[0033] In the method for preparing alumina microspheres according to the present invention, in step (2), sodium aluminate solution is added dropwise until the pH of the system is 8-9.5.

[0034] In the method for preparing alumina microspheres according to the present invention, in step (3), the solid content of the dispersion of the boehmite precursor is 5-8 wt%.

[0035] In the method for preparing alumina microspheres according to the present invention, in step (3), the particle diameter of the boehmite microspheres is 200-800 μm and the coefficient of variation is 3-8%.

[0036] In the method for preparing alumina microspheres according to the present invention, in step (3), the organic solvent is C1-C. 10 The monobasic saturated organic amine is preferably trioctylamine.

[0037] In the method for preparing alumina microspheres according to the present invention, in step (3), the drying conditions are: drying temperature of 60-80℃ and drying time of 5-20h.

[0038] In the method for preparing alumina microspheres according to the present invention, in step (4), the calcination conditions are: calcination temperature of 900-1100℃ and calcination time of 4-10h.

[0039] According to the present invention, preferably, the alumina microspheres are prepared in a microchannel reactor. There is no particular limitation on the type of microchannel reactor; the microchannel reactor may be a single-channel reactor and / or a multi-channel reactor.

[0040] According to the present invention, the additive is selected from at least one of Zn, Mg, Ce and Zr.

[0041] According to the present invention, based on the total weight of the supported catalyst, the content of the active component copper is 10-60 wt%, preferably 20-50 wt%, more preferably 48.8-49.3 wt%; the content of the promoter (metal element) is 0.1-10 wt%, preferably 1-5 wt%, more preferably 1.1-1.2 wt%; and the content of the support is 30-90 wt%, preferably 40-80 wt%, more preferably 49.5-50.1 wt%.

[0042] According to the present invention, the preparation method of the supported catalyst includes: impregnating the alumina microsphere support in a solution containing copper salt and auxiliary precursor compound by an equal volume, and then drying and calcining to obtain the supported catalyst.

[0043] According to the present invention, the copper salt is selected from at least one of copper nitrate, copper sulfate, and copper acetate.

[0044] According to the present invention, the concentration of copper salt in the solution is 0.2-12 mol / L, preferably 2-10 mol / L.

[0045] According to the present invention, the precursor compound of the adjuvant is at least one selected from zinc nitrate, magnesium nitrate, cerium nitrate, and zirconium oxynitrate.

[0046] According to the present invention, the concentration of the auxiliary precursor compound in the solution is 0.1-5 mol / L, preferably 1-2 mol / L.

[0047] According to the present invention, the drying conditions are: a drying temperature of 60-140℃, preferably 70-90℃; and a drying time of 2-10h, preferably 6-8h.

[0048] According to the present invention, the calcination conditions are as follows: the calcination temperature is 200-300℃, preferably 200-250℃; the calcination time is 2-10h, preferably 3-5h.

[0049] According to the present invention, in the presence of hydrogen and a catalyst, octenal and an inert solvent are reacted to obtain a product containing octenol, wherein the reaction temperature is 80-150°C and the reaction pressure is 2-7 MPa; preferably, the reaction is carried out at 90-110°C and the reaction pressure is 3-5 MPa.

[0050] According to the present invention, the liquid hourly weight hourly space velocity (LIHSV) of the octenal is 0.1-5 h⁻¹. -1 The molar ratio of hydrogen to octenal is (1-25):1, and preferably, the liquid hourly space velocity (LHSV) of the octenal is 0.5-1.5 h⁻¹. -1 The molar ratio of hydrogen to octenal is (2-10):1.

[0051] According to the present invention, the weight ratio of octenal to inert solvent is 1:(1-20), preferably, the weight ratio of octenal to inert solvent is 1:(5-10).

[0052] According to the present invention, the inert solvent is a C1-C8 saturated alcohol, preferably at least one of methanol, ethanol, isopropanol, hexanol and octanol.

[0053] According to a further preferred embodiment of the present invention, in the preparation process of the alumina microspheres, the multi-channel reactor is an eight-channel reactor. The eight-channel reactor includes a continuous phase distribution layer, a first droplet generation layer, a second droplet generation layer, and a dispersed phase distribution layer. The continuous phase distribution layer consists of petal-shaped resistance distribution channels and eight fluid outlets at their ends, a continuous phase vertical inlet, and four positioning holes. Each branch of the fluid is called a stage, and a certain resistance is added before each fluid branch. The width of the channel decreases as the circumference radius of the starting end of each stage increases. The first droplet generation layer has eight T-shaped channels, four positioning holes, and eight through holes to meet the requirements of the continuous phase flowing from the distribution layer to the generation layer. The second droplet generation layer has a similar structure to the first droplet generation layer, and also has eight droplet outlets distributed at the end of the main T-shaped channel. The dispersed phase distribution layer has a similar structure to the continuous phase distribution layer, and in addition to the petal-shaped resistance distribution channels and the eight dispersed phase outlets at their ends, it also has a dispersed phase fluid inlet and eight product outlets.

[0054] According to the present invention, preferably, the process of preparing alumina microspheres is described using an eight-channel reactor as an example. Using aluminum sol as the dispersed phase and an organic solvent as the continuous phase, the flow rate of the continuous phase is adjusted to fill the continuous phase distribution layer and flow into the droplet generation layer, then out through the outlet. The flow rate of the continuous phase is eventually stabilized at 6-10 mL / min. The flow rate of the dispersed phase is then adjusted to 1-4 mL / min to fill the dispersed phase distribution layer and flow into the droplet generation layer. Further, droplets are generated under the shearing action of the continuous phase. The droplets solidify in an oil column to obtain gel microspheres. After drying and calcination, alumina microspheres with a diameter of 200-800 μm and a coefficient of variation of 3-8% are obtained.

[0055] The present invention will be described in detail below through embodiments.

[0056] In the following examples and comparative examples:

[0057] Octenal conversion rate = (moles of octenal in the raw material - moles of unreacted octenal) ÷ ​​moles of octenal in the raw material × 100%.

[0058] Octenol selectivity = number of moles of octenol in the product ÷ (number of moles of octenal in the feed - number of moles of unreacted octenal) × 100%.

[0059] The diameter of the alumina microspheres was measured using scanning electron microscopy.

[0060] The method for testing the coefficient of variation is as follows: the number of alumina microspheres in a unit area is measured by scanning electron microscopy, and the diameter of each alumina microsphere is measured. Then, the coefficient of variation is calculated according to the formula.

[0061] The coefficient of variation is calculated using the following formula:

[0062]

[0063] CV: Coefficient of variation, n: Alumina microsphere count, X i Diameter of a single alumina microsphere. Average diameter of all alumina microspheres.

[0064] Specific surface area, pore volume, and pore size distribution were measured by N2 adsorption-desorption method.

[0065] The content of copper component was determined by X-ray fluorescence spectrometry.

[0066] The copper component metal dispersion was measured by a dynamic chemisorption analyzer. The copper metal dispersion = number of active copper atoms on the catalyst surface ÷ total number of copper atoms in the catalyst.

[0067] Octenol is a commercially available product from Aladdin Company, brand name E156033.

[0068] All reagents used were commercially available and of analytical grade.

[0069] Preparation Example 1

[0070] This preparation example illustrates the preparation of alumina microspheres.

[0071] (1) Weigh 22.56g of sodium hydroxide and 17.5g of sodium aluminate and dissolve them in 250mL of deionized water to obtain a sodium aluminate solution for later use; wherein, the molar ratio of sodium to aluminum in the sodium aluminate solution is 3.6:1;

[0072] (2) Weigh 88.4g of aluminum sulfate into 500mL of deionized water, add the sodium aluminate solution with an aluminum ion concentration of 0.85mol / L prepared in step (1) dropwise into the aluminum sulfate solution with a concentration of 0.5mol / L until the pH is 8.5, stir at room temperature for 60min to obtain a dispersion of boehmite precursor, and use this as the dispersed phase.

[0073] (3) The solid content of the boehmite precursor dispersion was 7.5 wt%. The continuous phase and the liquid in the oil column were both made of trioctylamine, an organic solvent. First, the flow rate of the continuous phase was adjusted so that it filled the continuous phase distribution layer and flowed into the droplet generation layer, and then flowed out from the outlet. The flow rate of the continuous phase was finally stabilized at 6 mL / min. Then, the flow rate of the dispersed phase was adjusted to 2 mL / min so that it filled the dispersed phase distribution layer and flowed into the droplet generation layer, and droplets were generated under the shearing action of the continuous phase. After the droplets solidified in the oil column and dried at 80 °C for 12 h, boehmite microspheres with a diameter of 800 μm and a coefficient of variation of 7.9% were obtained.

[0074] (4) The boehmite microspheres were calcined at 1100°C for 6 hours in an air atmosphere to obtain alumina microspheres with θ-Al2O3 as the main crystal phase.

[0075] XRF characterization showed that the sulfur content of the alumina microspheres was 0.08 wt%.

[0076] BET characterization showed that the alumina microspheres had a specific surface area of ​​100 m² / g, a pore volume of 0.8 mL / g, and a pore size distribution between 20-40 nm. In addition, the alumina microspheres had a particle diameter of 800 μm, a coefficient of variation of 7.9%, and a water absorption rate of 180%.

[0077] Preparation Example 2

[0078] This preparation example illustrates the preparation of alumina microspheres.

[0079] Alumina microspheres were prepared using the same method as in Preparation Example 1, with steps (1), (2), and (3) being exactly the same. The difference was that in step (4), the boehmite microspheres were calcined at 1000°C for 6 hours in an air atmosphere to obtain alumina microspheres with δ-Al2O3 as the main crystal phase.

[0080] XRF characterization showed that the sulfur content of the alumina microspheres was 0.15 wt%.

[0081] BET characterization showed that the alumina microspheres had a specific surface area of ​​140 m² / g, a pore volume of 1.2 mL / g, and a pore size distribution of 25-40 nm. In addition, the alumina microspheres had a particle diameter of 800 μm, a coefficient of variation of 7.9%, and a water absorption rate of 195%.

[0082] Preparation Example 3

[0083] This preparation example illustrates the preparation of alumina microspheres.

[0084] (1) Weigh 22.56g of sodium hydroxide and 17.5g of sodium aluminate and dissolve them in 250mL of deionized water to obtain a sodium aluminate solution for later use; wherein, the molar ratio of sodium to aluminum in the sodium aluminate solution is 3.6:1;

[0085] (2) Weigh 88.4g of aluminum sulfate into 500mL of deionized water, add the sodium aluminate solution with an aluminum ion concentration of 0.85mol / L prepared in step (1) dropwise into the aluminum sulfate solution with a concentration of 0.5mol / L until the pH is 9.5, stir at room temperature for 60min to obtain a dispersion of boehmite precursor, and use this as the dispersed phase.

[0086] (3) The solid content of the boehmite precursor dispersion was 7.5 wt%. The continuous phase and the liquid in the oil column were both made of trioctylamine, an organic solvent. First, the flow rate of the continuous phase was adjusted so that it filled the continuous phase distribution layer and flowed into the droplet generation layer, and then flowed out from the outlet. The flow rate of the continuous phase was finally stabilized at 6 mL / min. Then, the flow rate of the dispersed phase was adjusted to 2 mL / min so that it filled the dispersed phase distribution layer and flowed into the droplet generation layer, and droplets were generated under the shearing action of the continuous phase. After the droplets solidified in the oil column and dried at 80 °C for 12 h, boehmite microspheres with a diameter of 700 μm and a coefficient of variation of 7.5% were obtained.

[0087] (4) The boehmite microspheres were calcined at 1050°C for 6 hours in an air atmosphere to obtain alumina microspheres with a mixed phase of δ-Al2O3 and θ-Al2O3.

[0088] XRF characterization showed that the sulfur content of the alumina microspheres was 0.09 wt%.

[0089] BET characterization showed that the alumina microspheres had a specific surface area of ​​98 m² / g, a pore volume of 0.6 mL / g, and a pore size distribution between 20-40 nm. In addition, the alumina microspheres had a particle diameter of 700 μm, a coefficient of variation of 7.5%, and a water absorption rate of 180%.

[0090] Preparation Example 4

[0091] This preparation example illustrates the preparation of alumina microspheres.

[0092] Alumina microspheres were prepared using the same method as in Preparation Example 3, with steps (1), (2), and (3) being exactly the same. The difference was that in step (4), the boehmite microspheres were calcined at 1100°C for 6 hours in an air atmosphere to obtain alumina microspheres with the θ-Al2O3 phase as the main crystal phase.

[0093] XRF characterization showed that the sulfur content of the alumina microspheres was 0.08 wt%.

[0094] BET characterization showed that the alumina microspheres had a specific surface area of ​​86 m² / g, a pore volume of 0.5 mL / g, and a pore size distribution of 20-40 nm. In addition, the alumina microspheres had a particle diameter of 700 μm, a coefficient of variation of 7.5%, and a water absorption rate of 170%.

[0095] Preparation Example 5

[0096] This preparation example illustrates the preparation of the supported catalyst S1. The specific preparation process is as follows:

[0097] (1) The alumina microspheres prepared in Preparation Example 1 were used.

[0098] (2) Dissolve 21g of copper nitrate trihydrate and 1.3g of magnesium nitrate hexahydrate in 10mL of deionized water and stir evenly. Load the product onto the alumina microsphere carrier using the equal volume impregnation method. Place the impregnated product in an oven and dry it at 80℃ for 5 hours. Then place the dried product in a muffle furnace and calcine it at 250℃ for 3 hours in an air atmosphere to obtain catalyst S1.

[0099] XRF characterization showed that the supported catalyst contained 49.0% copper and 1.1% Mg.

[0100] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 5.6%.

[0101] Preparation Example 6

[0102] This preparation example illustrates the preparation of the supported catalyst S2. The specific preparation process is as follows:

[0103] (1) Alumina microspheres prepared using Preparation Example 2.

[0104] (2) Dissolve 19g of copper nitrate trihydrate and 1.2g of magnesium nitrate hexahydrate in 10mL of deionized water and stir evenly. Load the product onto the alumina microsphere carrier using the equal volume impregnation method. Place the impregnated product in an oven and dry it at 80°C for 5 hours. Then place the dried product in a muffle furnace and calcine it at 250°C for 3 hours in an air atmosphere to obtain catalyst S2.

[0105] XRF characterization showed that the supported catalyst contained 49.3% copper and 1.1% Mg.

[0106] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 5.4%.

[0107] Preparation Example 7

[0108] This preparation example illustrates the preparation of the supported catalyst S3. The specific preparation process is as follows:

[0109] (1) Alumina microspheres prepared using Preparation Example 3.

[0110] (2) Dissolve 21g of copper nitrate trihydrate and 1.3g of magnesium nitrate hexahydrate in 10mL of deionized water and stir evenly. Load the product onto the alumina microsphere carrier using the equal volume impregnation method. Place the impregnated product in an oven and dry it at 80°C for 5 hours. Then place the dried product in a muffle furnace and calcine it at 250°C for 3 hours in an air atmosphere to obtain catalyst S3.

[0111] XRF characterization showed that the supported catalyst contained 49.1% copper and 1.1% Mg.

[0112] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 5.4%.

[0113] Preparation Example 8

[0114] This preparation example illustrates the preparation of the supported catalyst S4. The specific preparation process is as follows:

[0115] (1) Alumina microspheres prepared using Preparation Example 4.

[0116] (2) Dissolve 22g of copper nitrate trihydrate and 1.5g of magnesium nitrate hexahydrate in 10mL of deionized water and stir evenly. Load the product onto the alumina microsphere carrier using the equal volume impregnation method. Place the impregnated product in an oven and dry it at 80°C for 5 hours. Then place the dried product in a muffle furnace and calcine it at 250°C for 3 hours in an air atmosphere to obtain catalyst S4.

[0117] XRF characterization showed that the supported catalyst contained 48.8% copper and 1.2% Mg.

[0118] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 5.0%.

[0119] Comparative Preparation Example 1

[0120] This comparative example illustrates the preparation of the supported catalyst D1. The specific preparation process is as follows:

[0121] (1) A commercially available alumina support was calcined at 1000℃ for 6 hours in air to obtain an alumina support with a mixed crystalline phase of δ-Al2O3 and θ-Al2O3. BET characterization showed that the commercially available alumina support had a surface area of ​​104 m² / g, a pore volume of 0.6 mL / g, a pore size distribution of 20-40 nm, and a water absorption rate of 90%. XRF characterization showed that sulfur was not detected.

[0122] (2) Dissolve 20g of copper nitrate trihydrate and 1.5g of magnesium nitrate hexahydrate in 10mL of deionized water and stir until homogeneous. Load the mixture onto a commercially available alumina support using an equal-volume impregnation method. Dry the impregnated product in an oven at 80°C for 5 hours. Then, place the dried product in a muffle furnace and calcine it at 250°C in air for 3 hours. Repeat the above operation twice to obtain catalyst D1.

[0123] XRF characterization showed that the supported catalyst contained 40.3% copper and 1.1% Mg.

[0124] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 2.2%.

[0125] Comparative Preparation Example 2

[0126] This comparative example illustrates the preparation of the supported catalyst D2. The specific preparation process is as follows:

[0127] (1) The boehmite microspheres obtained in Preparation Example 1 were calcined at 600°C for 6 hours in air to obtain alumina microspheres with the crystalline phase γ-Al₂O₃. XRF characterization showed that the sulfur content of the alumina microspheres was 2.1 wt%. BET characterization showed that the specific surface area of ​​the microspheres was 350 m² / g, the pore volume was 1.6 mL / g, the pore size distribution was 15-30 nm, and the water absorption rate was 210%.

[0128] (2) Dissolve 18g of copper nitrate trihydrate and 1.2g of magnesium nitrate hexahydrate in 10mL of deionized water and stir evenly. Load the product onto the alumina microsphere carrier using the equal volume impregnation method. Place the impregnated product in an oven and dry it at 80℃ for 5 hours. Then place the dried product in a muffle furnace and calcine it at 250℃ in air atmosphere for 3 hours to obtain catalyst D2.

[0129] XRF characterization showed that the supported catalyst contained 48.9% copper and 1.1% Mg.

[0130] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 5.2%.

[0131] Comparative preparation example 3

[0132] This comparative example illustrates the preparation of the supported catalyst D3. The specific preparation process is as follows:

[0133] (1) Weigh 22.56g of sodium hydroxide and 17.5g of sodium aluminate and dissolve them in 250mL of deionized water to obtain a sodium aluminate solution for later use; wherein, the molar ratio of sodium to aluminum in the sodium aluminate solution is 3.6:1;

[0134] (2) Weigh 88.4g of aluminum sulfate into 500mL of deionized water, add the sodium aluminate solution with an aluminum ion concentration of 0.85mol / L prepared in step (1) dropwise into the aluminum sulfate solution with a concentration of 0.5mol / L until the pH is 8.5, stir at room temperature for 60min to obtain a dispersion of boehmite precursor, and use this as the dispersed phase.

[0135] (3) Aluminum butoxide sol with a solid content of 7.5 wt% was selected as the dispersed phase, and octanol, an organic solvent, was used as the continuous phase and the liquid in the oil column. First, the flow rate of the continuous phase was adjusted so that it filled the continuous phase distribution layer and flowed into the droplet generation layer, and then flowed out from the outlet. The flow rate of the continuous phase was eventually stabilized at 6 mL / min. Then, the flow rate of the dispersed phase was adjusted to 2 mL / min so that it filled the dispersed phase distribution layer and flowed into the droplet generation layer, where droplets were further generated under the shearing action of the continuous phase. After the droplets solidified in the oil column and dried at 120 °C for 12 h, boehmite microspheres with a diameter of 700 μm and a coefficient of variation of 7.2% were obtained.

[0136] (4) The boehmite microspheres obtained in step (3) were calcined at 1050℃ for 6 hours in air to obtain alumina microspheres with a mixed phase of δ-Al2O3 and θ-Al2O3. XRF characterization showed that the sulfur content of the alumina microspheres was 0.09 wt%. BET characterization showed that the specific surface area of ​​the alumina microspheres was 106 m² / g, the pore volume was 0.8 mL / g, the pore size distribution was 20-40 nm, and the water absorption rate was 120%.

[0137] (5) Dissolve 15g of copper nitrate trihydrate and 1g of magnesium nitrate hexahydrate in 10mL of deionized water and stir until homogeneous. Load the mixture onto alumina microspheres using an equal-volume impregnation method. Dry the impregnated product in an oven at 80°C for 5 hours. Then, place the dried product in a muffle furnace and calcine it at 250°C for 3 hours in air. Repeat the above operation once to obtain catalyst D3.

[0138] XRF characterization showed that the supported catalyst contained 49.7% copper and 1.2% Mg.

[0139] Dynamic chemisorption analysis revealed that the copper metal dispersion in this supported catalyst was 3.4%.

[0140] Comparative preparation example 4

[0141] This comparative example illustrates the preparation of the supported catalyst D4. The specific preparation process is as follows:

[0142] The supported catalyst D4 was prepared using the same method as in Preparation Example 5, except that “copper nitrate” in step (2) was replaced with “nickel nitrate”.

[0143] XRF characterization showed that the supported catalyst had a nickel loading of 49.6% and a Mg loading of 1.1%.

[0144] Dynamic chemisorption analysis revealed that the nickel metal dispersion in this supported catalyst was 5.4%.

[0145] Example 1

[0146] This embodiment illustrates the preparation of octenol by hydrogenation of octenal under different conditions.

[0147] The performance of the supported catalyst S1 prepared in Preparation Example 5 in the liquid-phase hydrogenation of octenal to octenol was tested.

[0148] 25 mL of supported catalyst S1 was measured and loaded into a stainless steel fixed-bed reactor. High-purity nitrogen gas was introduced at a flow rate of 300 mL / min, and the temperature was raised to 120 °C. The high-purity nitrogen gas was then switched to hydrogen gas, and the flow rate was adjusted to 200 mL / min. The temperature was raised to 250 °C and maintained for 4 h to reduce the catalyst. Subsequently, the temperature was slowly lowered, and a mixture of octenal and inert solvent (ethanol) was continuously introduced into the fixed bed for evaluation. The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity (LHSV) of octenal, and the weight ratio of octenal to inert solvent are shown in Table 1. The test results are also shown in Table 1.

[0149] Example 2

[0150] This embodiment illustrates the preparation of octenol by hydrogenation of octenal under different conditions.

[0151] Octenol was prepared by hydrogenation of octenal using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst S2 prepared in Preparation Example 6”.

[0152] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0153] Example 3

[0154] This embodiment illustrates the preparation of octenol by hydrogenation of octenal under different conditions.

[0155] Octenol was prepared by hydrogenation of octenal using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst S3 prepared in Preparation Example 7”.

[0156] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0157] Example 4

[0158] This embodiment illustrates the preparation of octenol by hydrogenation of octenal under different conditions.

[0159] Octenol was prepared by hydrogenation of octenal using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst S4 prepared in Preparation Example 8”.

[0160] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0161] Comparative Example 1

[0162] Octenal was hydrogenated to prepare octenol using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst D1 prepared in Comparative Preparation Example 1”.

[0163] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0164] Comparative Example 2

[0165] Octenol was prepared by hydrogenation of octenal using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst D2 prepared in Comparative Preparation Example 2”.

[0166] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0167] Comparative Example 3

[0168] Octenal was hydrogenated to octenol using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst D3 prepared in Comparative Preparation Example 3”.

[0169] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0170] Comparative Example 4

[0171] Octenal was hydrogenated to prepare octenol using the same method as in Example 1, except that “supported catalyst S1” in Example 1 was replaced with “supported catalyst D4 prepared in Comparative Preparation Example 4”.

[0172] The corresponding reaction temperature, hydrogen pressure, liquid hourly space velocity of octenal, and weight ratio of octenal to inert solvent are shown in Table 1. The test results are shown in Table 1.

[0173] Table 1

[0174]

[0175] As shown in Table 1, the supported catalyst provided by this invention maintains a large pore size and low sulfur content under high-temperature calcination conditions due to the layered stacking structure of the alumina microsphere support, which anchors active metal atoms and increases the loading and dispersion of the metal active components, thereby giving the catalyst a high degree of dispersion of active components. Based on this, the preparation of octenol using this supported catalyst can significantly improve the conversion rate of octenal and the selectivity of octenol under the same reaction conditions.

[0176] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. (1240322)

[0177] I95222BHY

[0178] Within the scope of the technical concept of this invention, various simple modifications can be made to the technical solution of this invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed in this invention and are all within the protection scope of this invention.

Claims

1. A method for preparing octenol by hydrogenation of octenal, the method comprising: Octenal and an inert solvent are reacted in the presence of hydrogen and a catalyst to yield octenol; wherein the catalyst is a supported catalyst, comprising a support and an active component and an auxiliary agent supported on the support, characterized in that the support is alumina microspheres, the sulfur content of the alumina microspheres is 0.01-0.2 wt%, the alumina microspheres are δ-Al₂O₃ and / or θ-Al₂O₃, and the pore size distribution of the alumina microspheres is between 15-45 nm; the active component is copper, and the copper dispersion in the supported catalyst is 4.5-6%.

2. The method according to claim 1, wherein, The sulfur content in the alumina microspheres is 0.05-0.15 wt%. And / or, the copper dispersion in the supported catalyst is 4.6-5.6%.

3. The method according to claim 1 or 2, wherein, The alumina microspheres have a layered stacked structure; And / or, the pore size distribution of the alumina microspheres is between 18-40 nm; And / or, the alumina microspheres have a particle diameter of 200-800 μm, a coefficient of variation of 3-8%, and a water absorption rate of 150%-250%.

4. The method according to any one of claims 1-3, wherein, The preparation of the alumina microsphere carrier includes: (1) Prepare a sodium aluminate solution by mixing sodium hydroxide and sodium aluminate; (2) The sodium aluminate solution was added dropwise to the aluminum sulfate solution to obtain a dispersion of boehmite precursor; (3) Using the dispersion of the boehmite precursor as the dispersed phase and an organic solvent as the continuous phase, the dispersed phase is formed into droplets under the shearing action of the continuous phase, and gel microspheres are obtained by solidification and then dried to obtain boehmite microspheres. (4) The boehmite microspheres are then calcined to obtain alumina microspheres.

5. The method according to claim 4, wherein, In step (1), the molar ratio of sodium to aluminum in the sodium aluminate solution is (3-6):1; And / or, in step (1), the concentration of aluminum ions in the sodium aluminate solution is 0.1-1 mol / L; And / or, in step (2), the concentration of the aluminum sulfate solution is 0.1-1 mol / L; And / or, in step (2), sodium aluminate solution is added dropwise until the pH of the system is 8-9.5; And / or, in step (3), the solid content of the dispersion of the boehmite precursor is 5-8 wt%; And / or, in step (3), the organic solvent is C1-C 10 The monobasic saturated organic amine, preferably trioctylamine; And / or, in step (4), the calcination conditions include: a calcination temperature of 900-1100℃ and a calcination time of 4-10h.

6. The method according to claim 4 or 5, wherein, The alumina microspheres are prepared in a microchannel reactor; the microchannel reactor is a single-channel reactor and / or a multi-channel reactor.

7. The method according to claim 1, wherein, The additive is selected from at least one of Zn, Mg, Ce and Zr.

8. The method according to any one of claims 1-7, wherein, Based on the total weight of the supported catalyst, the content of the active component copper is 10-60 wt%, preferably 20-50 wt%; the content of the auxiliary agent is 0.1-10 wt%, preferably 1-5 wt%; and the content of the support is 30-90 wt%, preferably 40-80 wt%.

9. The method according to any one of claims 1-8, wherein, The preparation method of the supported catalyst includes: impregnating the alumina microsphere support in a solution containing copper salt and auxiliary precursor compound by an equal volume, and then drying and calcining to obtain the supported catalyst.

10. The method according to claim 9, wherein, The copper salt is selected from at least one of copper nitrate, copper sulfate, and copper acetate; And / or, the concentration of copper salt in the solution is 0.2-12 mol / L, preferably 2-10 mol / L; And / or, the precursor compound of the adjuvant is at least one of zinc nitrate, magnesium nitrate, cerium nitrate, and zirconium oxynitrate; And / or, the concentration of the auxiliary precursor compound in the solution is 0.1-5 mol / L, preferably 1-2 mol / L; And / or, the calcination conditions are: calcination temperature of 200-300℃, preferably 200-250℃; calcination time of 2-10h, preferably 3-5h.

11. The method according to any one of claims 1-10, wherein, The reaction conditions include: a temperature of 80-150℃ and a reaction pressure of 2-7 MPa; preferably, a temperature of 90-110℃ and a reaction pressure of 3-5 MPa. And / or, the liquid hourly weight hourly space velocity (LHSV) of the octenal is 0.1-5 h⁻¹. -1 The molar ratio of hydrogen to octenal is (1-25):1, and preferably, the liquid hourly space velocity (LHSV) of the octenal is 0.5-1.5 h⁻¹. -1 The molar ratio of hydrogen to octenal is (2-10):1; And / or, the weight ratio of the octenal to the inert solvent is 1:(1-20), preferably, the weight ratio of the octenal to the inert solvent is 1:(5-10); And / or, the inert solvent is a C1-C8 saturated alcohol, preferably at least one of methanol, ethanol, isopropanol, hexanol and octanol.

Images