Method for preparing isopentenol from 3-methyl-1-butene

Abstract

The invention provides a method for preparing isopentenol from 3-methyl-1-butene, which comprises the following steps: oxidizing 3-methyl-1-butene to obtain a 2-isopropyl ethylene oxide intermediate, and then isomerizing the intermediate to obtain the isopentenol. The synthesis route is novel, the cheap refined C5 byproduct 3-methyl-1-butene is used as a starting raw material, the isopentenol is simply and efficiently prepared through two-step reaction of epoxidation, isomerization and the like, and an economical and feasible route is provided for preparation of the product; and secondly, in the isomerization reaction in the second step, lithium phosphate treated by sodium alcoholate or potassium alcoholate is used as a catalyst, so that the isomerization reaction of the epoxy intermediate is efficiently realized, and the isopentenol is conveniently and quickly prepared. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of fine chemicals, and specifically relates to a method for preparing isopentenol by taking 3-methyl-1-butene as a raw material through two-step reactions such as epoxidation and isomerization. Background Art

[0002] The scientific name of isopentanol is 3-methyl-2-butene-1-ol. It is a colorless transparent liquid at room temperature. It is easily soluble in water with a solubility of 170g / L. It is miscible in common organic solvents such as ethanol, ether, and ethyl acetate. The molecular structure of isopentanol contains double bonds and alcohol hydroxyl functional groups. It is a very important synthetic intermediate and can be used in the production of a variety of fine chemicals, such as citral, vitamin A, vitamin E, vitamin K, pyrethroid insecticides, polycarboxylic acid water reducers, etc. It has a wide range of industrial uses.

[0003] Although there are many methods for synthesizing isopentenol, few of them have practical application value. In industry, isobutylene and formaldehyde are mainly used as raw materials. The two undergo a Prince reaction to obtain isopentenol, which undergoes a hydroisomerization reaction under the action of a catalyst to finally obtain isopentenol. This method has a large amount of starting materials that are easily available and inexpensive, making it a very competitive synthesis route. However, the first step of this route, Prince, requires high temperature and high pressure, and the reaction conditions are harsh, resulting in huge equipment investment; in addition, in the hydroisomerization reaction, isopentenol is easily hydrogenated to obtain a by-product, isopentanol, so the hydroisomerization yield is low, only about 90%:

[0004]

[0005] There are also literature reports that use acetone and acetylene as raw materials. First, the two react to obtain methyl butynol, which is then selectively hydrogenated to obtain methyl butenol. The latter undergoes an intramolecular 1,3-hydroxyl isomerization reaction under the action of an isomerization catalyst to finally obtain isopentenol. Although the starting materials of this route are relatively cheap and easy to obtain, the synthesis route of this method is relatively long, and the synthesis involves flammable and explosive acetylene, which is very dangerous. Therefore, almost no manufacturers in the market currently use this method to produce isopentenol:

[0006]

[0007] Isoprene can also be used as a raw material for the synthesis of isopentenol. The specific route is as follows: isoprene is reacted with hydrogen chloride to obtain isopentenyl chloride, which is directly hydrolyzed or reacted with sodium acetate to obtain isopentenyl acetate, which is then hydrolyzed to obtain isopentenol. Few manufacturers currently use this route to produce isopentenol, because this method not only has a long synthesis route, but also has the disadvantages of hydrogen chloride and acetic acid corrosion problems, poor hydrogen chloride addition yield, etc. Compared with the aforementioned synthesis route, this method also produces more wastewater:

[0008]

[0009] In summary, the main synthesis methods of isopentenol currently include isobutylene method, acetone acetylene method, isoprene method, etc. The isobutylene method is the main production method in industry at present, but each synthesis route still has the disadvantages of harsh reaction conditions, yield to be improved, more three wastes, etc.; in order to obtain isopentenol more economically and cheaply, it is urgent to develop a novel synthesis route, starting from low-priced raw materials, to prepare isopentenol in a green, efficient and low-cost manner, thereby promoting the development of downstream products and applications of isopentenol. Summary of the invention

[0010] The purpose of the present invention is to provide an efficient synthesis route of isopentenol, using 3-methyl-1-butene as a starting material, and obtaining an isopentenol product through two-step reactions such as epoxidation and isomerization. The synthesis route of the present invention is short, the conditions are mild, the total yield is high, and the potential application value is good.

[0011] In order to achieve the above objectives and the above technical effects, the present invention adopts the following technical solutions:

[0012] A method for synthesizing isopentanol specifically comprises: using 3-methyl-1-butene as a raw material, oxidizing 3-methyl-1-butene with a peroxide under the action of an epoxidation catalyst to produce an epoxidation reaction to obtain a 2-isopropyl oxirane intermediate, and then the intermediate undergoes an intramolecular isomerization reaction under the action of an isomerization catalyst to obtain an isopentanol product;

[0013] The reaction route is shown below:

[0014]

[0015] In the present invention, the peroxide may be, but is not limited to, hydrogen peroxide, tert-butyl hydroperoxide, tert-butyl peroxide, ethyl peroxide, isopropyl peroxide, peracetic acid, etc., preferably hydrogen peroxide; the peroxide is used in the form of a solution, and the concentration of the solution is preferably 30-50%;

[0016] Preferably, the molar ratio of the peroxide to 3-methyl-1-butene is 1:1.5-3.0.

[0017] In the present invention, the epoxidation catalyst can be titanium silicon molecular sieve TS-1, TS-2, Ti-Beta, Ti-MCM-22, Ti-MCM-41, Ti-SBA-15, Ti-MWW, Ti-HMS, Ti-MOR, Ti-TUN, Ti-ZSM-5, and quaternary ammonium salt of phosphotungstate heteropolyacid, etc.;

[0018] Preferably, the amount of the catalyst is 0.5-2.5 wt % of the mass of the peroxide solution.

[0019] In the present invention, the solvent for the epoxidation reaction can be but is not limited to toluene, tetrahydrofuran, methyl tert-butyl ether, dichloromethane, dichloroethane, ethyl acetate, methanol, ethanol, acetonitrile, etc.; preferably methanol, acetonitrile, etc.; the mass ratio of the solvent to the peroxide solution is preferably 2.0-5.0:1.0.

[0020] In the present invention, the epoxidation reaction can be carried out in an intermittent reactor, a continuous reactor, a shell-and-tube reactor, or the like.

[0021] Preferably, the reaction temperature is 50-80° C.; and / or the reaction time is 0.5-6.0 hours; and / or the epoxidation reaction is carried out under the protection of a gas such as nitrogen or argon, with a gas pressure of 0.5-3.0 MPa.

[0022] In the present invention, the isomerization catalyst is a lithium phosphate catalyst treated with sodium alkoxide and / or potassium alkoxide; the treatment method is: adding lithium phosphate powder to an alcohol solution of sodium alkoxide or potassium alkoxide, stirring and replacing at room temperature for 2-6 hours, and then filtering, drying, and granulating to obtain;

[0023] The sodium alcoholate or potassium alcoholate may be, but is not limited to, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium isopropoxide, potassium methoxide, potassium ethoxide, potassium isopropoxide, potassium tert-butoxide, etc., and the amount used is 4-11 mol% of the lithium phosphate;

[0024] In the present invention, when treating lithium phosphate, the solvent is preferably methanol, ethanol, isopropanol, tert-butanol, etc.; the amount of the solvent is 3-5 times the mass of the lithium phosphate;

[0025] The treatment method causes a certain degree of lithium-sodium or lithium-potassium ion exchange to occur on the surface of lithium phosphate, thereby enhancing the alkalinity of the lithium phosphate catalyst and improving the catalyst activity.

[0026] In the present invention, the weight hourly space velocity of the isomerization reaction is 0.2-2.0h -1 , preferably 0.5-2.0h -1 The catalyst has a diameter of 1 to 4 mm, a length of 2 to 3 mm, and a bulk density of 0.6 to 0.8 g / mL; the solid catalyst and the ceramic θ ring are mixed and loaded.

[0027] In the present invention, the temperature of the isomerization reaction is preferably 250-300° C., the reaction pressure is normal pressure, and the carrier gas is preferably nitrogen.

[0028] In the present invention, the feed liquid of the isomerization reaction may be added with a solvent or may not be added with a solvent, preferably without adding a solvent; if a solvent is added, the solvent may be but is not limited to ethyl acetate, tetrahydrofuran, methyl tert-butyl ether, ethanol, acetonitrile, diethyl ether, etc.

[0029] The present invention adopts the above technical solution and has the following positive effects:

[0030] 1. The synthetic route used in this method is novel. It uses cheap 3-methyl-1-butene, a byproduct of refining C5, as the starting material. After two steps of epoxidation and isomerization, isopentenol is prepared simply and efficiently, providing an economically feasible route for the preparation of the product and having good potential application value.

[0031] 2. The present invention uses lithium phosphate treated with sodium alcoholate or potassium alcoholate as a catalyst, which efficiently realizes the isomerization reaction of the epoxy intermediate and obtains the isopentenol product in high yield. DETAILED DESCRIPTION

[0032] The present invention is described in detail below by examples, but the present invention is not limited to the following examples.

[0033] The main raw material information is as follows:

[0034] 3-Methyl-1-butene, AR, Aladdin reagent;

[0035] Hydrogen peroxide (50%), hydrogen peroxide (30%), tert-butyl hydroperoxide (30%), J&K reagent;

[0036] Phenyl peroxide (40%), cumene peroxide (35%), chili pepper reagent.

[0037] Ti-MWW, Ti-MCM-22, Ti-ZSM-5, quaternary ammonium salt of phosphotungstic heteropoly acid, Zibo Catalytic Molecular Sieve Company.

[0038] The gas chromatography test conditions of the present invention are as follows:

[0039] Instrument model: Agilent 8890B; Chromatographic column: Capillary column HP-3 (30m×0.30mm×0.25μm); Initial temperature 60℃, raised to 120℃ at a rate of 5℃ / min; then raised to 200℃ at a rate of 10℃ / min, maintained for 10.0min. Carrier gas high-purity nitrogen, split ratio 30:1, split flow 42mL / min. Carrier gas saving: 19mL / min, start waiting time 5.0min. Injection temperature 250℃, detector FID, detector temperature 250℃, air flow 350mL / min, hydrogen flow 30mL / min, tail gas flow 60mL / min, injection volume 0.2μL.

[0040] Embodiment 1:

[0041] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0042] In the air, add the solvent acetonitrile (81.6g) and the catalyst titanium silicon molecular sieve Ti-MWW (0.82g) to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, start the autoclave and stir, then add the substrate 3-methyl-1-butene (84.2g, 1.2mol) and hydrogen peroxide (40.8g, 0.6mol, concentration 50wt%) to the autoclave through a metering pump, and finally fill with 2.0MPaG nitrogen. Turn on the autoclave jacket heating, control the temperature in the reactor to 60°C, and react under uniform stirring (400rpm). After 4 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of hydrogen peroxide was >99.7%, and the selectivity of 2-isopropyl oxirane was 94.5%.

[0043] Embodiment 2:

[0044] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0045] In the air, add the solvent acetonitrile (173.5g) and the catalyst titanium silicon molecular sieve Ti-MWW (0.17g) to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, start the autoclave and stir, then add the substrate 3-methyl-1-butene (53.7g, 0.765mol) and hydrogen peroxide (34.7g, 0.51mol, concentration 50wt%) to the autoclave through a metering pump, and finally fill with 3.0MPaG nitrogen. Turn on the autoclave jacket heating, control the temperature in the reactor to 80°C, and react under uniform stirring (400rpm). After 0.5 hours of reaction, the reaction solution was sampled through a double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of hydrogen peroxide was >99.3%, and the selectivity of 2-isopropyl oxirane was 92.3%.

[0046] Embodiment 3:

[0047] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0048] In the air, add the solvent acetonitrile (156.5g) and the catalyst titanium silicon molecular sieve Ti-MWW (1.04g) to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, start the autoclave and stir, then add the substrate 3-methyl-1-butene (96.8g, 1.38mol) and hydrogen peroxide (52.2g, 0.46mol, concentration 30wt%) to the autoclave through a metering pump, and finally fill with 0.5MPaG nitrogen. Turn on the autoclave jacket heating, control the temperature in the reactor to 50°C, and react under uniform stirring (400rpm). After 4 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of hydrogen peroxide was >99.8%, and the selectivity of 2-isopropyl oxirane was 94.0%.

[0049] Embodiment 4:

[0050] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0051] In the air, add solvent toluene (793.0g) and catalyst titanium silicon molecular sieve Ti-MCM-22 (3.97g) to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, start the autoclave and stir, then add substrate 3-methyl-1-butene (115.7g, 1.65mol) and tert-butyl hydroperoxide solution (198.3g, 0.66mol, concentration 30wt%, solvent tert-butyl alcohol) to the autoclave through a metering pump, and finally fill with 2.0MPaG nitrogen. Turn on the autoclave jacket heating, control the temperature in the reactor to 60°C, and react under uniform stirring (400rpm). After 4 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of tert-butyl hydroperoxide was >99.0%, and the selectivity of 2-isopropyl oxirane was 93.9%.

[0052] Embodiment 5:

[0053] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0054] In the air, add solvent acetonitrile (248.7g) and catalyst titanium silicon molecular sieve Ti-ZSM-5 (2.49g) in turn to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, open the autoclave and stir, then add substrate 3-methyl-1-butene (75.8g, 1.08mol) and peroxybenzene ethyl solution (123.45g, 0.36mol, concentration 40wt%, solvent benzene ethyl) to the autoclave through a metering pump, and finally charge 2.0MPaG nitrogen. Open the autoclave jacket heating, control the temperature in the reactor to 60°C, and react under uniform stirring (400rpm). After 4 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of styrene peroxide was >99.7%, and the selectivity of 2-isopropyl oxirane was 98.9%.

[0055] Embodiment 6:

[0056] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0057] In the air, at room temperature, solvent dichloromethane (296g) and catalyst quaternary ammonium salt of phosphotungstic heteropolyacid (1.48g) were added to a 500mL autoclave successively, the autoclave was sealed, the air in the autoclave was replaced by nitrogen 3 times, and then a 2.0MPaG nitrogen pressure test was performed to detect leakage. After confirming that there was no leakage, the nitrogen in the autoclave was vented to normal pressure, the autoclave was opened and stirred, and then substrate 3-methyl-1-butene (71.5g, 1.02mol) and isopropyl peroxide solution (147.8g, 0.34mol, concentration 35wt%, solvent isopropyl benzene) were added to the autoclave by a metering pump, and finally 2.0MPaG nitrogen was charged. The autoclave jacket was opened for heating, and the temperature in the control reactor was 60°C, and the reaction was stirred at a uniform speed (400rpm). After 5 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of isopropyl peroxide was >99.3%, and the selectivity of 2-isopropyl oxirane was 97.4%.

[0058] Embodiment 7:

[0059] Preparation of 2-isopropyloxirane by epoxidation of 3-methyl-1-butene

[0060] In the air, add the solvent acetonitrile (245g) and the catalyst titanium silicon molecular sieve Ti-MWW (0.98g) to a 500mL autoclave at room temperature, seal the autoclave, replace the air in the autoclave with nitrogen 3 times, then use 2.0MPaG nitrogen to maintain pressure and check for leaks, after confirming that there is no leak, vent the nitrogen in the autoclave to normal pressure, start the autoclave and stir, then add the substrate 3-methyl-1-butene (151.5g, 2.16mol) and hydrogen peroxide (49.0g, 0.72mol, concentration 50wt%) to the autoclave through a metering pump, and finally charge 2.0MPaG nitrogen. Turn on the autoclave jacket heating, control the temperature in the reactor to 60°C, and react under uniform stirring (400rpm). After 4 hours of reaction, the reaction solution was sampled by double valve, and after adding internal standard cyclohexane, the concentrations of the raw material 3-methyl-1-butene and the target product 2-isopropyl oxirane in the reaction solution were detected and analyzed by GC, and the conversion rate and selectivity of the epoxidation reaction were calculated. The results showed that the conversion rate of hydrogen peroxide was >99.8%, and the selectivity of 2-isopropyl oxirane was 96.8%.

[0061] Embodiment 8:

[0062] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0063] The lithium phosphate catalyst used is lithium phosphate treated with sodium ethoxide. The treatment method is as follows: lithium phosphate (50 g) is added to an ethanol (200 g) solution of sodium ethoxide (2.94 g) to obtain a suspension. The obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and sodium ions in the lithium phosphate solid. After stirring and replacing for 4 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with sodium ethoxide, with a diameter of 1 to 2 mm and a length of 2 to 3 mm.

[0064] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 20 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 280 ° C; turn on the vaporizer heating and raise its temperature to 200 ° C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 0.33 g / min and the liquid mass space velocity was 0.4 h -1, the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~76%, and the selectivity of isopentenol is ~99%.

[0065] Embodiment 9:

[0066] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0067] The lithium phosphate catalyst used is lithium phosphate treated with sodium ethoxide. The treatment method is as follows: lithium phosphate (50 g) is added to an ethanol (150 g) solution of sodium ethoxide (1.47 g) to obtain a suspension. The obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and sodium ions in the lithium phosphate solid. After stirring and replacing for 2 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with sodium ethoxide, with a diameter of 1 to 2 mm and a length of 2 to 3 mm.

[0068] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 15 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 250°C; turn on the vaporizer heating and raise its temperature to 200°C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 0.17 g / min and the liquid mass space velocity was 0.2 h -1 , the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~71%, and the selectivity of isopentenol is ~99%.

[0069] Embodiment 10:

[0070] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0071] The lithium phosphate catalyst used is lithium phosphate treated with sodium methoxide. The treatment method is as follows: lithium phosphate (50 g) is added to a methanol (150 g) solution of sodium methoxide (2.33 g) to obtain a suspension. The obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and sodium ions in the lithium phosphate solid. After stirring and replacing for 6 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with sodium methoxide, with a diameter of 1 to 2 mm and a length of 2 to 3 mm.

[0072] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 50 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 300 ° C; turn on the vaporizer heating and raise its temperature to 220 ° C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 1.67 g / min and the liquid mass space velocity was 2.0 h -1 , the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~83%, and the selectivity of isopentenol is ~96%.

[0073] Embodiment 11:

[0074] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0075] The lithium phosphate catalyst used is lithium phosphate treated with sodium tert-butoxide. The treatment method is as follows: lithium phosphate (50g) is added to a tert-butanol (250g) solution of sodium tert-butoxide (4.15g) to obtain a suspension. The obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and sodium ions in the lithium phosphate solid. After stirring and replacing for 4 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with sodium tert-butoxide, with a diameter of 1-2mm and a length of 2-3mm.

[0076] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 35 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 280°C; turn on the vaporizer heating and raise its temperature to 200°C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 1.17 g / min and the liquid mass space velocity was 1.4 h -1 , the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~75%, and the selectivity of isopentenol is ~98%.

[0077] Embodiment 12:

[0078] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0079] The lithium phosphate catalyst used is lithium phosphate treated with potassium tert-butoxide. The treatment method is as follows: lithium phosphate (50g) is added to a tert-butanol (150g) solution of potassium tert-butoxide (4.85g) to obtain a suspension. The obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and potassium ions in the lithium phosphate solid. After stirring and replacing for 5 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with potassium tert-butoxide, with a diameter of 1-2mm and a length of 2-3mm.

[0080] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 30 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 270°C; turn on the vaporizer heating and raise its temperature to 200°C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 0.5 g / min and the liquid mass space velocity was 0.6 h -1, the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~73%, and the selectivity of isopentenol is ~98%.

[0081] Embodiment 13:

[0082] Synthesis of Isopentenol from 2-Isopropylethylene Oxide by Gas Phase Isomerization

[0083] The lithium phosphate catalyst used is lithium phosphate treated with potassium isopropoxide. The treatment method is as follows: lithium phosphate (50 g) is added to an isopropanol (200 g) solution of potassium isopropoxide (4.24 g) to obtain a suspension, and the obtained suspension is stirred at room temperature to promote the exchange of some lithium ions and potassium ions in the lithium phosphate solid. After stirring and replacing for 5 hours, it is filtered and dried, and then ground, extruded and granulated to obtain the lithium phosphate catalyst treated with potassium isopropoxide, which has a diameter of 1 to 2 mm and a length of 2 to 3 mm.

[0084] A tubular reactor was used for gas phase isomerization reaction. The reaction tube was 40 cm long and 2.5 cm in inner diameter. Lithium phosphate catalyst (50 g) and ceramic θ ring were mixed in the reaction tube. When conducting gas phase isomerization reaction, first open the N2 carrier gas inlet and outlet valves, turn on the nitrogen carrier gas, and the flow rate is 40 mL / min; turn on the reaction tube heating jacket and raise the temperature of the reaction tube to 280°C; turn on the vaporizer heating and raise its temperature to 210°C. After the temperature of the vaporizer and the reaction tube stabilized, turn on the metering pump to pump the raw material 2-isopropyl ethylene oxide into the vaporizer. The raw material liquid feed rate was 0.83 g / min and the liquid mass space velocity was 1.0 h -1 , the raw materials are vaporized and mixed with N2 to pass through the catalyst layer, and an isomerization reaction occurs on the catalyst surface. After the reaction gas phase exits the reaction tube, it enters the cooler for rapid cooling, and then enters the phase separation tank. The unreacted raw materials and products become liquid phases and remain in the tank; the carrier gas N2 and other non-condensable gases are discharged as tail gas. The sampler is located on the pipeline between the cooler and the phase separation tank. Samples are taken regularly through the sampler. The GC chromatography analyzes the composition of the reaction liquid. The results show that the conversion rate of 2-isopropyl ethylene oxide is ~75%, and the selectivity of isopentenol is ~99%.

Claims

1. A method for preparing isopentenol, comprising: Under the action of an epoxidation catalyst, 3-methyl-1-butene is oxidized by peroxide to undergo an epoxidation reaction to obtain a 2-isopropyl oxirane intermediate, which undergoes an intramolecular isomerization reaction under the action of an isomerization catalyst to obtain isopentenol.

2. The method according to claim 1, wherein: The peroxide includes at least one of hydrogen peroxide, tert-butyl hydroperoxide, tert-butyl peroxide, ethyl peroxide, isopropyl peroxide, and peracetic acid, preferably hydrogen peroxide; preferably, the peroxide is used in the form of a solution, and the concentration of the solution is preferably 30-50wt%; Preferably, the molar ratio of the peroxide to 3-methyl-1-butene is 1:1.5-3.

0.

3. The method according to claim 1 or 2, wherein: The epoxidation catalyst is selected from at least one of titanium silicon molecular sieve TS-1, TS-2, Ti-Beta, Ti-MCM-22, Ti-MCM-41, Ti-SBA-15, Ti-MWW, Ti-HMS, Ti-MOR, Ti-TUN, Ti-ZSM-5, and quaternary ammonium salt of phosphotungstic heteropoly acid; Preferably, the amount of the catalyst is 0.5-2.5 wt % of the mass of the peroxide solution.

4. The method according to any one of claims 1 to 3, wherein: The epoxidation reaction has a reaction temperature of 50-80° C., and / or a reaction time of 0.5-6.0 hours, and / or a reaction pressure of 0.5-3.0 MPa.

5. The method according to any one of claims 1 to 4, wherein: The isomerization catalyst is a lithium phosphate catalyst treated with sodium alcoholate and / or potassium alcoholate.

6. The method according to claim 5, wherein: The treatment method is: adding lithium phosphate to an alcohol solution of sodium alcoholate and / or potassium alcoholate, stirring and replacing at room temperature for a period of time, preferably 2-6 hours, and then filtering, drying and granulating; preferably, the catalyst has a diameter of 1-4 mm and a length of 2-3 mm.

7. The method according to claim 5 or 6, wherein: The sodium alcoholate includes at least one of sodium methoxide, sodium ethoxide, sodium tert-butoxide, and sodium isopropoxide; the potassium alcoholate includes at least one of potassium methoxide, potassium ethoxide, potassium isopropoxide, and potassium tert-butoxide. Preferably, the amount of sodium alkoxide and / or potassium alkoxide is 4-11 mol % of the lithium phosphate.

8. The method according to any one of claims 5 to 7, wherein: When treating lithium phosphate, the solvent is selected from at least one of methanol, ethanol, isopropanol and tert-butanol; preferably, the amount of the solvent is 3-5 times the mass of the lithium phosphate.

9. The method according to any one of claims 1 to 8, wherein: The weight hourly space velocity of the isomerization reaction is 0.2-2.0h -1 .

10. The method according to any one of claims 1 to 9, wherein: The temperature of the isomerization reaction is 250-300°C.

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