Method for synthesizing cyclohexene and co-producing primary alcohol

Abstract

The invention belongs to the technical field of catalytic synthesis of fine chemicals, and particularly relates to a method for co-production of cyclohexene and primary alcohol. The method comprises the following steps: introducing cyclohexane and low-carbon alkylene oxide into a fixed bed reactor, and carrying out chemical reaction on a tungsten and molybdenum oxide catalyst treated under gamma rays to obtain cyclohexene and primary alcohol. The method has excellent selectivity on cyclohexene and primary alcohol, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic synthesis of fine chemicals, and specifically relates to a process and a catalyst for co-producing primary alcohols from cyclohexene. Background Art

[0002] Cyclohexene is an important chemical raw material. It can be directly used to synthesize hexanediol and adipic acid. It can be obtained by ring-opening polymerization with carbon dioxide to obtain polycarbonate. It can be widely used in organic synthesis and has broad application prospects in chemical production, pharmaceutical industry and petroleum industry. Primary alcohols are also an important class of organic compounds, which are widely used in chemical industry, medical treatment, food industry, industrial and agricultural production. For example, this type of compound is used as an organic solvent with excellent performance, an important intermediate raw material in chemical synthesis, etc.

[0003] The generation of cyclohexene is mainly divided into benzene partial hydrogenation method and cyclohexane selective dehydrogenation method. Taking cyclohexane selective dehydrogenation technology as an example, Chinese patent CN112844352B discloses an application of a carbon material catalyst in cyclohexane oxidative dehydrogenation, and nano diamonds treated by high temperature roasting catalyze cyclohexene products with high selectivity in cyclohexane oxidative dehydrogenation reaction, and effectively suppress combustion reaction. Wherein the cyclohexene product selectivity is 60%. And primary alcohols are mostly prepared by aldehyde hydrogenation process, such as Chinese patent CN113105299B discloses a method for synthesizing primary alcohols in water phase, with aldehyde as raw material, water is selected as solvent, and the aldehyde is obtained by catalytic hydrogenation reaction in the presence of a water-soluble catalyst to obtain primary alcohol, and the catalyst used is a metal iridium complex. Summary of the invention

[0004] The object of the present invention is to provide a method for synthesizing cyclohexene and co-producing primary alcohol.

[0005] The main feature of the present invention is that a catalyst containing abundant oxygen vacancies and high metal dispersion is prepared by using high-energy gamma rays as an aid. Under the action of the catalyst, cyclohexane and low-carbon epoxyalkane undergo chemical reactions to obtain cyclohexene and primary alcohols with high selectivity.

[0006] The preparation method of a copper-based catalyst of the present invention is achieved by the following technical scheme: Cyclohexane and low-carbon alkylene oxide are introduced into a fixed bed reactor, and chemical reactions occur on a catalyst to obtain cyclohexene and primary alcohol; the catalyst comprises one of tungsten and molybdenum oxides.

[0007] Generally, the molar ratio of the low carbon alkylene oxide to cyclohexane is 1-3.

[0008] The reaction temperature is 300-600°C, the pressure is normal pressure-2MPa, and the cyclohexane gas hourly space velocity is 1×10 4 ~1×10 5 h-1。

[0009] The catalyst is prepared by a sol-gel method, wherein a metal precursor salt and citric acid are mixed into a mixed solution, and then evaporated, roasted, granulated and formed to obtain a catalyst precursor, and the catalyst precursor is placed in a particle bombardment box and treated under gamma rays to obtain a catalyst.

[0010] The molar ratio of the citric acid to the metal precursor salt is 2-5, and the evaporation temperature is 70-90°C.

[0011] The calcination atmosphere is one of nitrogen and argon; the calcination temperature is 300-500° C., and the calcination time is 1-3 hours.

[0012] The frequency of the gamma ray is 1×10 13 ~1×10 28 Hz.

[0013] The gamma ray treatment time is 5 to 20 minutes.

[0014] The low-carbon alkylene oxide is one of ethylene oxide and propylene oxide.

[0015] The cyclohexene selectivity of the method of the present invention is above 90%.

[0016] Compared with the existing technology, the cyclohexene selectivity is high and the high value-added product primary alcohol can be co-produced. Implementation

[0017] The following examples are only used to further explain the content and effects of the present invention, rather than to limit the present invention.

[0018] Example 1 1 mol of ammonium metatungstate and 5 mol of citric acid were dissolved in 1000 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 70 °C and calcined at 500 °C for 1 h in a nitrogen atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 28 After treatment with Hz gamma rays for 5 min, catalyst cat1 was obtained.

[0019] Example 2 1 mol of ammonium molybdate and 4 mol of citric acid were dissolved in 800 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 80 °C and calcined at 400 °C for 1.5 h in a nitrogen atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 20 After treatment with Hz gamma rays for 10 min, catalyst cat2 was obtained.

[0020] Example 3 1 mol of ammonium metatungstate and 3 mol of citric acid were dissolved in 800 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 90 °C and calcined at 450 °C for 2 h in an argon atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1 × 10 18 After treatment with Hz gamma rays for 15 min, catalyst cat3 was obtained.

[0021] Example 4 1 mol of ammonium metatungstate and 2 mol of citric acid were dissolved in 1000 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 90 °C and calcined at 300 °C for 3 h in an argon atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 15 After treatment with Hz gamma rays for 18 min, catalyst cat4 was obtained.

[0022] Example 5 1 mol of ammonium molybdate and 3 mol of citric acid were dissolved in 800 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 80 °C and calcined at 400 °C for 2 h in an argon atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain a catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 13 After treatment with Hz gamma rays for 20 min, catalyst cat5 was obtained.

[0023] Example 6 1 mol of ammonium metatungstate and 3.5 mol of citric acid were dissolved in 1000 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 90 °C and calcined at 450 °C for 3 h in an argon atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 22 After treatment with Hz gamma rays for 10 min, catalyst cat6 was obtained.

[0024] Example 7 1 mol of ammonium molybdate and 5 mol of citric acid were dissolved in 1000 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 70 °C and calcined at 400 °C for 1 h in a nitrogen atmosphere. After cooling, the catalyst precursor was taken out and granulated and formed to obtain the catalyst precursor. The catalyst precursor was placed in a particle bombardment box at 1×10 20 After treatment with Hz gamma rays for 15 min, catalyst cat7 was obtained.

[0025] Example 8 1 mol of ammonium molybdate and 5 mol of citric acid were dissolved in 1000 mL of deionized water to prepare a mixed solution, which was then evaporated to dryness at 70°C and calcined at 400°C for 1 h in a nitrogen atmosphere; after cooling, the solution was taken out, granulated and formed to obtain catalyst cat8. Example 9

[0026] O2-TG was used to determine the oxygen vacancy ratio of the catalyst (expressed as weight gain %), and XPS and ICP were used to detect the dispersion of the metal.

[0027] The cat1~cat8 catalysts prepared above were used in the reaction of cyclohexane and low-carbon alkylene oxides, and the results are shown in the table below.

[0028] Table 1 Catalyst performance test results

[0029] It can be seen from Table 1 that the catalyst prepared by the method of the present invention has a higher oxygen vacancy ratio and metal dispersion, and has good catalytic performance in the reaction of cyclohexane, alkylene oxide to cyclohexene and primary alcohol.

Claims

1. A method for synthesizing cyclohexene and producing primary alcohols, characterized in that Cyclohexane and low-carbon alkylene oxide are introduced into a fixed bed reactor, and chemical reactions occur on a catalyst to obtain cyclohexene and primary alcohol; the catalyst comprises one of tungsten and molybdenum oxides.

2. The method according to claim 1, characterized in that The molar ratio of the low-carbon alkylene oxide to cyclohexane is 1-3.

3. The method according to claim 1, characterized in that The reaction temperature is 300-600°C, the pressure is normal pressure-2MPa, and the cyclohexane gas hourly space velocity is 1×10 4 ~1×10 5 h -1 .

4. The method according to claim 1, characterized in that: The catalyst is prepared by a sol-gel method, wherein a metal precursor salt and citric acid are prepared into a mixed solution, and then the solution is evaporated, calcined, granulated and formed to obtain a catalyst precursor. The catalyst precursor is placed in a particle bombardment box and treated under gamma rays to obtain a catalyst.

5. The method according to claim 4, characterized in that The molar ratio of the citric acid to the metal precursor salt is 2-5.

6. The method according to claim 4, characterized in that The evaporation temperature is 70-90°C.

7. The method according to claim 4, characterized in that The calcination atmosphere is one of nitrogen and argon; the calcination temperature is 300-500° C., and the calcination time is 1-3 hours.

8. The method according to claim 4, characterized in that The frequency of the gamma ray is 1×10 13 ~1×10 28 Hz.

9. The method according to claim 4, characterized in that The gamma ray treatment time is 5 to 20 minutes.

10. The method according to claim 1, characterized in that The low-carbon alkylene oxide is one of ethylene oxide and propylene oxide.

11. The method according to claim 1, characterized in that: The selectivity of cyclohexene is above 90%.

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