Preparation method of Guerbet alcohol

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a Guerbet alcohol preparation method which comprises the following steps: reacting primary alcohol under the conditions of a mesoporous carbon sphere supported nickel catalyst, inorganic strong alkali and inert gas to obtain Guerbet alcohol; the preparation method of the mesoporous carbon sphere loaded nickel catalyst comprises the following steps: carbonizing and oxidizing hollow phenolic resin spheres prepared by a template method, and loading metallic nickel to obtain the mesoporous carbon sphere loaded nickel catalyst. By selecting the mesoporous carbon sphere loaded nickel catalyst, the catalytic efficiency, the stability and the service life of the catalyst are improved, and the content of a polymer product is low after mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing Guerbet alcohol. Background Art

[0002] Guerbet alcohols are a class of highly branched alcohol compounds widely used in cosmetics, lubricants, and other fields. The typical preparation mechanism for Guerbet alcohols involves catalytic dehydrogenation, condensation, and intramolecular dehydration of primary alcohols to produce branched alcohols. Current industrial production methods typically involve dehydrogenating alcohols to form aldehydes using metal catalysts in an alkaline environment, followed by polymerization and subsequent hydrogenation to produce the Guerbet alcohols. However, current metal catalysts suffer from low catalytic efficiency, low stability, and short lifespan.

[0003] Therefore, a method for preparing Guerbet alcohols is proposed, which improves the catalytic efficiency, catalyst stability and lifespan. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a method for preparing Guerbet alcohols, which improves the catalytic efficiency, catalyst stability and lifespan.

[0005] The inventive concept of the present invention is that by selecting a mesoporous carbon sphere-supported nickel catalyst to catalyze the generation of Guerbet alcohols from primary alcohols, the catalytic efficiency, catalyst stability and life can be improved, and the content of polymer products after the reaction is low.

[0006] A first aspect of the present invention provides a method for preparing Guerbet alcohols.

[0007] Specifically, a method for preparing Guerbet alcohols comprises reacting a primary alcohol in the presence of a mesoporous carbon sphere-supported nickel catalyst, an inorganic strong base, and an inert gas to prepare the Guerbet alcohols; The preparation steps of the mesoporous carbon sphere-supported nickel catalyst include: carbonizing, oxidizing, and supporting metal nickel on hollow phenolic resin spheres prepared by a template method to prepare the mesoporous carbon sphere-supported nickel catalyst.

[0008] Preferably, the feeding amount of the primary alcohol is greater than or equal to 100 kg and less than or equal to 10 tons; further preferably, the feeding amount of the primary alcohol is greater than or equal to 800 kg and less than or equal to 2 tons.

[0009] Compared with the prior art, the method for preparing Guerbet alcohols provided in the first aspect has the following beneficial effects: by selecting a mesoporous carbon sphere-supported nickel catalyst, the catalytic efficiency, catalyst stability and life are improved, and the content of polymer products after the reaction is low.

[0010] Preferably, the primary alcohol includes a fatty primary alcohol; further preferably, the primary alcohol includes a straight-chain or branched fatty primary alcohol with a carbon number of C6-C12.

[0011] Preferably, the preparation steps of the hollow phenolic resin balls include: (1) In parts by mass, 0.9-1.1 parts of resorcinol, 1-1.3 parts of furfural, and 0.005-0.015 parts of hydrogen chloride ethanol solution are stirred and mixed at low temperature under nitrogen for 20-60 minutes, and then 0.15-0.20 parts of urotropine and 0.05-0.15 parts of block copolymer template are added and stirred and mixed for 1-3 hours to prepare a precursor solution; (2) adding 0.01-0.03 parts of crystalline wax and 0.01-0.03 parts of emulsifier to the precursor solution, heating and stirring under nitrogen to obtain a prepolymer; (3) The prepolymer is heated and stirred under nitrogen to volatilize the ethanol, and then filtered, washed, and dried to obtain phenolic resin balls; (4) adding the phenolic resin balls into a sulfuric acid solution and stirring under reflux to remove the block copolymer template, washing, and drying to obtain the hollow phenolic resin balls.

[0012] Preferably, in step (1), the low temperature is -5 to 15°C; further preferably, the low temperature is 0 to 10°C.

[0013] Preferably, in step (1), the block copolymer template is Pluronic F127.

[0014] Preferably, in step (1), the hydrogen chloride content of the hydrogen chloride ethanol solution is 20 wt%-40 wt%; further preferably, the hydrogen chloride content of the hydrogen chloride ethanol solution is 25 wt%-35 wt%.

[0015] Preferably, in step (2), the emulsifier includes Span-80.

[0016] Preferably, in step (2), the temperature of the heating and stirring is 50-70° C., and the time of the heating and stirring is 2-3 h.

[0017] Preferably, in step (3), the temperature of the heating and stirring is 100-130°C.

[0018] Preferably, in step (4), the sulfuric acid content of the sulfuric acid solution is 20-30 wt%.

[0019] Preferably, in step (4), the temperature of the reflux stirring is 90-120° C., and the time of the reflux stirring is 20-30 h.

[0020] Preferably, the carbonization step includes calcining at 800-900° C. for 1-2 hours under inert gas conditions to obtain mesoporous carbon spheres.

[0021] Preferably, the oxidation step comprises reacting 1 of the mesoporous carbon spheres with 3-4 mL of 69-70 wt% concentrated nitric acid solution in a high-pressure reactor at 110-130° C. for 4-5 hours, followed by cooling, washing, and drying.

[0022] Preferably, the step of loading metallic nickel comprises: (I) ultrasonically immersing the oxidized mesoporous carbon spheres in a 0.4-0.5 g / mL nickel acetate aqueous solution for 3-5 hours, and then rotary evaporating and drying at 110-130° C. to obtain an intermediate; (II) reducing and calcining the intermediate at 450-550° C. for 5-7 h under hydrogen conditions to obtain the mesoporous carbon sphere-supported nickel catalyst.

[0023] Preferably, in the step (I), 35-45 mL of nickel acetate aqueous solution is required for every 8-12 g of the oxidized mesoporous carbon spheres.

[0024] It should be noted that the added amounts of the mesoporous carbon spheres and the nickel acetate aqueous solution can be increased in proportion according to production needs.

[0025] Preferably, the mesoporous carbon sphere-supported nickel catalyst has a diameter of 200-2000 μm and a mesopore diameter of 40 nm to 50 nm.

[0026] Preferably, the inert gas includes at least one of nitrogen and argon; further preferably, the inert gas is nitrogen.

[0027] Preferably, the mass ratio of the primary alcohol to the mesoporous carbon sphere-supported nickel catalyst is 1: 0.001-0.01.

[0028] Preferably, the mass ratio of the primary alcohol to the inorganic base is 1: 0.005-0.05.

[0029] Preferably, the inorganic strong base includes at least one of potassium hydroxide and sodium hydroxide; further preferably, the inorganic strong base is potassium hydroxide.

[0030] Compared with the prior art, the present invention has the following beneficial effects: By selecting mesoporous carbon sphere-loaded nickel catalyst to catalyze the generation of Guerbet alcohols from primary alcohols, the catalytic efficiency, catalyst stability and life can be improved, and the content of polymer products after the reaction is low (less than 1%). DETAILED DESCRIPTION

[0031] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0032] Unless otherwise specified, the raw materials, reagents, or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0033] The steps for preparing the mesoporous carbon sphere-supported nickel catalyst in the embodiment of the present invention are as follows: (1) 100 kg of resorcinol and 114 kg of furfural were added to a conical flask protected by nitrogen, followed by the addition of 2.14 kg of hydrogen chloride ethanol solution. The mixture was stirred magnetically at 9 °C for 35 min. 36.38 kg of urotropine and 21.4 kg of block copolymer Pluronic F127 were added to the conical flask and stirred for 125 min to prepare a precursor solution. (2) Add the precursor solution to 4.28 kg of crystalline wax and 4.28 kg of Span-80, and stir at 60 °C for 2.5 h under nitrogen protection to obtain a prepolymer mixture; (3) The prepolymer mixture is heated to 100-130°C under nitrogen protection and stirred for 5 h to volatilize the alcohol in the prepolymer. The phenolic resin balls are obtained after filtration, washing and drying; (4) Phenolic resin balls were added to a 24.5 wt% sulfuric acid solution and refluxed at 100 °C for 26 h. The solution was washed with deionized water until neutral and dried to remove the template to obtain hollow phenolic resin balls. (5) Carbonization: Under inert gas protection, hollow phenolic resin balls were calcined at 850 °C for 1.5 h to obtain mesoporous carbon balls; (6) Oxidation: 1 kg of mesoporous carbon spheres and 3.5 L of concentrated nitric acid were placed in a high-pressure reactor containing a tetrafluoroethylene liner, reacted at 120 °C for 4.5 h, cooled to room temperature, washed with deionized water until neutral, and dried in an oven at 60 °C for 5 h; (7) Loading metallic nickel: 1 kg of oxidized mesoporous carbon spheres was added to 0.11 g / mL, 4 L nickel acetate aqueous solution and ultrasonically soaked for 4 h, and then rotary evaporated and dried at 120 °C and 800 rpm to obtain an intermediate; (8) The intermediate was transferred into a tube furnace and reduced in a hydrogen atmosphere at 500 °C for 6 h to obtain a mesoporous carbon sphere-supported nickel catalyst. Example 1

[0034] A four-necked flask equipped with a thermometer, water separator, reflux condenser, gas pipe, and mechanical stirrer was charged with 1000 kg of n-hexanol and 3 kg of sodium hydroxide. After nitrogen flow for 30 minutes, the temperature was raised to 60°C. Subsequently, 10 kg of mesoporous carbon sphere-supported nickel catalyst was added and the temperature was raised to 160°C for 2 hours. After cooling, the reaction mixture was washed with hot water until neutral, dried over anhydrous magnesium sulfate, filtered, and distilled under reduced pressure to obtain colorless, transparent 2-butyloctanol with a purity of 97%, a yield of 88%, and a polymer content of 0.84 wt%. Example 2

[0035] A four-necked flask equipped with a thermometer, water separator, reflux condenser, gas pipe, and mechanical stirrer was charged with 1000 kg of n-octanol and 3 kg of potassium hydroxide. After nitrogen flow for 30 minutes, the temperature was raised to 60°C. Subsequently, 10 kg of mesoporous carbon sphere-supported nickel catalyst was added and the temperature was raised to 180°C for 2 hours. After cooling, the reaction mixture was washed with hot water until neutral, dried over anhydrous magnesium sulfate, filtered, and distilled under reduced pressure to obtain colorless, transparent 2-hexyldecanol with a purity of 98% and a yield of 90%. The polymer content was less than 1 wt%. Example 3

[0036] A four-necked flask equipped with a thermometer, water separator, reflux condenser, gas pipe, and mechanical stirrer was charged with 1000 kg of isodecyl alcohol and 2.5 kg of potassium hydroxide. After nitrogen flow for 30 minutes, the temperature was raised to 60°C. Subsequently, 10 kg of mesoporous carbon sphere-supported nickel catalyst was added, and the temperature was raised to 220°C for 3 hours. After cooling, the reaction was washed with hot water until neutral, dried over anhydrous magnesium sulfate, filtered, and distilled under reduced pressure to obtain colorless, transparent 10-methyl-2-(6-methylheptyl)undecan-1-ol with a purity of 95% and a yield of 80%. The polymer content was less than 1 wt%. Example 4

[0037] A four-necked flask equipped with a thermometer, water trap, reflux condenser, gas pipe, and mechanical stirrer was charged with 1000 kg of n-dodecanol and 2 kg of potassium hydroxide. After nitrogen flow for 30 minutes, the temperature was raised to 60°C. Subsequently, 10 kg of mesoporous carbon sphere-supported nickel catalyst was added and the temperature was raised to 240°C for 5 hours. After cooling, the reaction mixture was washed with hot water until neutral, dried over anhydrous magnesium sulfate, filtered, and distilled under reduced pressure to obtain colorless, transparent 2-decyltetradecanol with a purity of 95% and a yield of 80%. The polymer content was less than 1 wt%.

[0038] Comparative Example 1 The hydrogenation catalyst of Comparative Example 1 is prepared as follows: (1) 2.22 kg of high-purity nano-alumina powder (γ phase, particle size 10-20 nm) was added to 150 L of trimethylsilane aqueous solution, stirred at 60 ° C for 12 hours, and naturally cooled to room temperature to obtain a reaction solution; every 35 L of the reaction solution was diluted with 105 L of deionized water, added to a hydrothermal kettle, hydroheated at 130 ° C for 36 hours, and naturally cooled to room temperature. The carrier was obtained by centrifugation, filtration, washing, and drying at 100 ° C for 12 hours. (2) 1 kg of the carrier was added to 4 L of 0.11 g / mL nickel acetate aqueous solution and ultrasonically soaked for 4 h. The product was dried by rotary evaporation at 120 °C and 800 rpm. The product was reduced in a tube furnace at 500 °C in a hydrogen atmosphere for 6 h to obtain a hydrogen catalyst.

[0039] A four-necked flask equipped with a thermometer, a water separator, a reflux condenser, a gas pipe, and a mechanical stirrer was charged with 1000 kg of n-hexanol and 3 kg of sodium hydroxide. After nitrogen was passed through for 30 minutes, the temperature was raised to 60°C. Subsequently, 10 kg of the hydrogenation catalyst of Comparative Example 1 was added and the temperature was raised to 160°C. The reaction was allowed to react for 2 hours. After the reaction was cooled, hot water was added and washed until neutral. After drying over anhydrous magnesium sulfate, the mixture was filtered and removed by vacuum distillation to obtain colorless, transparent 2-butyloctanol with a purity of 96%, a yield of 85%, and a polymer content of 3.4 wt%.

Claims

1. A method for preparing Guerbet alcohols, characterized in that: The preparation method comprises the following steps: reacting a primary alcohol under the conditions of a mesoporous carbon sphere-supported nickel catalyst, an inorganic strong base and an inert gas to prepare the Guerbet alcohol; The preparation steps of the mesoporous carbon sphere-supported nickel catalyst include: carbonizing, oxidizing, and supporting metal nickel on hollow phenolic resin spheres prepared by a template method to prepare the mesoporous carbon sphere-supported nickel catalyst.

2. The preparation method according to claim 1, characterized in that The primary alcohol includes a straight-chain or branched-chain aliphatic primary alcohol having a carbon number of C6-C12.

3. The preparation method according to claim 1, characterized in that The preparation steps of the hollow phenolic resin balls include: (1) In parts by mass, 0.9-1.1 parts of resorcinol, 1-1.3 parts of furfural, and 0.005-0.015 parts of hydrogen chloride ethanol solution are stirred and mixed at low temperature under nitrogen for 20-60 minutes, and then 0.15-0.20 parts of urotropine and 0.05-0.15 parts of block copolymer template are added and stirred and mixed for 1-3 hours to prepare a precursor solution; (2) adding 0.01-0.03 parts of crystalline wax and 0.01-0.03 parts of emulsifier to the precursor solution, heating and stirring under nitrogen to obtain a prepolymer; (3) The prepolymer is heated and stirred under nitrogen to volatilize the ethanol, and then filtered, washed, and dried to obtain phenolic resin balls; (4) adding the phenolic resin balls into a sulfuric acid solution and stirring under reflux to remove the block copolymer template, washing, and drying to obtain the hollow phenolic resin balls.

4. The preparation method according to claim 3, characterized in that In the step (1), the block copolymer template is Pluronic F127.

5. The preparation method according to claim 3, characterized in that In the step (2), the emulsifier includes Span-80.

6. The preparation method according to claim 3, characterized in that The carbonization step includes calcining the hollow phenolic resin balls at 800-900° C. for 1-2 hours under an inert gas condition to obtain mesoporous carbon balls.

7. The preparation method according to claim 3, characterized in that The oxidation step comprises reacting the hollow phenolic resin spheres with 3-4 mL of 69-70 wt% concentrated nitric acid solution in a high-pressure reactor at 110-130° C. for 4-5 hours, cooling, washing, and drying to obtain mesoporous carbon spheres.

8. The preparation method according to claim 7, characterized in that The step of loading metallic nickel comprises: (I) ultrasonically immersing the mesoporous carbon spheres in a 0.4-0.5 g / mL nickel acetate aqueous solution for 3-5 hours, and then rotary evaporating and drying at 110-130° C. to obtain an intermediate; (II) reducing and calcining the intermediate at 450-550° C. for 5-7 h under hydrogen conditions to obtain the mesoporous carbon sphere-supported nickel catalyst.

9. The preparation method according to claim 1, characterized in that The mass ratio of the primary alcohol to the mesoporous carbon sphere-supported nickel catalyst is 1:0.001-0.

01.

10. The preparation method according to claim 1, characterized in that The mass ratio of the primary alcohol to the inorganic strong base is 1:0.005-0.05.