Method and device for preparing cyclopentanol through catalytic hydration of cyclopentene

Abstract

The invention relates to the technical field of cyclopentanol preparation, in particular to a method and device for preparing cyclopentanol through catalytic hydration of cyclopentene, a catalyst is put into a reactor, the temperature is increased to 142-147 DEG C and is higher than the reaction temperature, the catalyst is subjected to thermal expansion, then vacuum pumping is conducted, dissolved gas adsorbed in resin and on the surface of the resin can be effectively removed, and the content of cyclopentanol in the resin can be effectively reduced. The pressure is increased to 2-2.2 MPa, the pressure is higher than the reaction pressure, and the holding time is 60-80 s, so that the structure of the catalyst is stable, and the subsequent catalytic reaction selectivity is high; according to the present invention, the reactants are mixed, pressurized and heated to the same environment as the reactor, and then are fed into the reactor, such that the stability, the safety and the vibration avoiding during the feeding process can be ensured, the reactants, the solvent and the catalyst have the same environment, the reaction can be stably performed, and the by-products are less.

Description

Technical Field

[0001] The present invention relates to the technical field of cyclopentanol preparation, and particularly to a method and device for catalytic hydration of cyclopentene to prepare cyclopentanol. Background Art

[0002] Cyclopentanol is an important raw material in the preparation of medicines, dyes and spices, and the demand is large. The catalytic hydration of cyclopentene to prepare cyclopentanol has the characteristics of high selectivity, mild reaction conditions, environmental friendliness, simple operation, high product purity, high economic efficiency and high safety, and has received extensive attention. The research of those skilled in the art on the catalytic hydration of cyclopentene to prepare cyclopentanol mainly includes the research of catalysts, the optimization of reaction conditions, the research of reaction mechanisms, the selection and optimization of solvents, the separation and purification of products, process control, etc., which have made great contributions to the development of the industry. Among them, the catalysts include ion exchange resins, acidic catalysts, metal catalysts, etc., and the optimization of reaction conditions includes reaction temperature, pressure, time, etc., providing a basis for the industrialization of the catalytic hydration of cyclopentene to prepare cyclopentanol.

[0003] In the process of using resin as a catalyst, before the reaction, an oxygen-free environment is created by vacuum pumping. During the reaction, the temperature is controlled at 130 - 135 °C and the pressure is 1.5 - 1.6 Mpa. The pressurization is achieved by filling a protective gas to ensure the conversion rate and selectivity. When adding the reactants, after adding the reactants, solvents and catalysts into the reactor, and then performing the operations of vacuum pumping and pressurization, due to the catalyst being wrapped, during the vacuum pumping process, the effect on the resin is reduced, and during the heating process, the temperature transfer is uneven, resulting in a decrease in the conversion rate. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method and device for catalytic hydration of cyclopentene to prepare cyclopentanol.

[0005] The present invention is realized by the following technical solutions: A method for catalytic hydration of cyclopentene to prepare cyclopentanol, comprising the following steps: Step A, pre-treatment of the reactor: Put a catalyst into the reactor. The catalyst is selected as Dowex 50WX2 type cation exchange resin, heat up to T1, where T1 is 142 - 147 °C, vacuum pump to P1, where P1 is 100 - 200 Pa, then fill nitrogen into the reactor and pressurize to P2, where P2 is 2 - 2.2 MPa, maintain for a time t1, where t1 is 60 - 80 s, relieve pressure to P3, where P3 is 1 - 1.1 MPa, and cool down to T2, where T2 is 110 - 113 °C; Step B: Feed the reactants. Mix cyclopentene, solvent, and water, then increase the pressure to P3 and raise the temperature to T2, and then feed them into the reactor pretreated in Step A. The solvent is selected as diethylene glycol dimethyl ether. The weight ratio among the catalyst, cyclopentene, solvent, and water is catalyst:cyclopentene: solvent:water = 0.1 - 0.2:1:1 - 2:3 - 5; Step C: Hydration reaction. Control the reactor temperature T4 and pressure P4. T4 is 130 - 135 °C, P4 is 1.5 - 1.6 Mpa. Start stirring, and the reaction duration is t2, where t2 is 4 - 5 h; Step D: Separation. Control the reactor temperature T5 and pressure P5. T5 is 15 - 20 °C, P5 is 0.1 Mpa. Filter the catalyst, and rectify the filtrate to obtain cyclopentanol, and the water and solvent are recycled.

[0006] Furthermore, the particle size of the catalyst is 0.8 - 1 mm, and the water is deionized water.

[0007] Furthermore, in Step A, T1 is 145 °C, P1 is 100 Pa, P2 is 2 MPa, t1 is 60 s, P3 is 1 MPa, and T2 is 110 °C.

[0008] Furthermore, in Step B, catalyst:cyclopentene: solvent:water = 0.2:1:1.5:4.

[0009] Furthermore, in Step C, T4 is 135 °C, P4 is 1.5 Mpa, and t2 is 4.5 h.

[0010] A device for implementing the method of catalytic hydration of cyclopentene to prepare cyclopentanol, comprising a mixer, a reactor, and a rectification column, The mixer is provided with a first feeding port. There is a first air pipe between the upper end of the reactor and the upper end of the mixer. A first booster pump and a first three-way valve are arranged on the first air pipe. The outlet end of the first booster pump is connected to the mixer. The first three-way valve is arranged between the first booster pump and the mixer. One port of the first three-way valve is connected to the outside through a first filter. The lower end of the mixer is connected to the reactor through a second booster pump. The outlet end of the second booster pump is connected to the reactor; The upper end of the reactor is connected to a nitrogen tank through a second air pipe. A third booster pump is arranged on the second air pipe. The outlet end of the third booster pump is connected to the reactor. The lower end of the reactor is connected to the rectification column through a filtering device. The filtering device is used to filter the catalyst, and the filtrate enters the rectification column; The extraction port of the rectification column is connected to a cyclopentanol tank, a solvent tank, and a cyclopentene tank through an extraction pipe.

[0011] Furthermore, the first booster pump and the third booster pump are both selected as air compressors, and the second booster pump is selected as a gear pump.

[0012] Furthermore, the outlet end of the second booster pump is connected to the lower end of the reactor, and a metering pump is arranged between the reactor and the filtration equipment.

[0013] The beneficial effects of the present invention are as follows: 1. Put the catalyst into the reactor, first heat up to 142 - 147 °C, which is higher than the reaction temperature, so that the catalyst undergoes thermal expansion, and then evacuate the air. This can effectively remove the dissolved gases adsorbed inside and on the surface of the resin. Then increase the pressure to 2 - 2.2 MPa, which is higher than the reaction pressure, and maintain for 60 - 80 s to make the structure of the catalyst stable, and the subsequent catalytic reaction has high selectivity. 2. After mixing the reactants, increase the pressure and temperature until it is the same as the reactor environment, and then put them into the reactor. This can ensure stability and safety during the input process, avoid vibration, and since the reactants, solvent, and catalyst are in the same environment, the reaction can proceed stably with fewer by-products. Description of the Drawings

[0014] Figure 1 It is a schematic diagram of the connection relationship of each device.

[0015] 101. Mixer; 102. Stirring motor 1; 103. Feeding port 1; 104. Discharge valve 1; 2. Filter; 3. First booster pump; 4. First three-way valve; 5. Second booster pump; 601. Reactor; 602. Stirring motor 2; 603. Discharge valve 2; 604. Metering pump; 605. Feeding port 2; 7. Filtration equipment; 8. Nitrogen tank; 9. Third booster pump; 10. Distillation column; 11. Product withdrawal pipe; 12. Cyclopentanol tank; 13. Solvent tank; 14. Cyclopentene tank; 15. Valve; 16. Discharge valve. Detailed Embodiments

[0016] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected", and "linked" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] In the following embodiments, Cyclopentene, Zhejiang Alpha Chemical Technology Co., Ltd., purity ≥ 98.0%; Solvent, diethylene glycol dimethyl ether, Nantong Runfeng Petrochemical Co., Ltd.; Catalyst, Dowex 50WX2 type cation exchange resin, Shanghai Yuanye Bio-Technology Co., Ltd., particle size 0.8 - 1 mm; Both booster pump 1 and booster pump 3 are air compressors, and booster pump 2 is a chemical gear pump; The metering pump is a chemical metering pump; Both the mixer and the reactor are jacketed reaction vessels, which can control the temperature. The volume value of the mixer is 1 / 3 of the volume value of the reactor. The volume of the mixer is 300 L. High-speed mixing is carried out in the mixer, and the stirring speed is 600 rpm. At a smaller volume, the length of the stirring teeth is small, and the resistance to high-speed stirring is small; The filtration equipment is a YXSG model filter produced by Henan Yongxin Technology Co., Ltd.

[0019] The method for preparing cyclopentanol by catalytic hydration of cyclopentene is completed in the device for realizing the method for preparing cyclopentanol by catalytic hydration of cyclopentene. The device for realizing the method for preparing cyclopentanol by catalytic hydration of cyclopentene is as Figure 1 shown, and includes a mixer, a reactor, and a distillation column.

[0020] Specifically, there is a feeding port 103 at the upper end of the mixer 101, and reactants are injected into it. The feeding port 103 is equipped with a sealing cover. The mixer 101 is connected to a stirring motor 102. There is a first air pipe connected between the upper end of the reactor 601 and the upper end of the mixer 101. A first booster pump 3 and a first three-way valve 4 are installed on the first air pipe. The outlet end of the first booster pump 3 is connected to the mixer 101. The first three-way valve 4 is installed between the first booster pump 3 and the mixer 101. One port of the first three-way valve 4 is connected to the outside through a filter 2. During the process of evacuating the reactor 601, the first booster pump 3 operates, and the first three-way valve 4 switches to be connected to the outside through the filter 2. The lower end of the mixer 101 is connected to the reactor 601 through a first discharge valve 104 and a second booster pump 5. The outlet end of the second booster pump 5 is connected to the reactor 601. After the reactants are mixed in the mixer 101, they are pumped into the reactor 601 through the second booster pump 5. At the same time, the first booster pump 3 operates to make the air flow at the upper end of the reactor 601 enter the mixer 101, thereby balancing the pressure between the reactor 601 and the mixer 101. The upper end of the reactor 601 is connected to a nitrogen tank 8 through a second air pipe. A third booster pump 9 is installed on the second air pipe. The outlet end of the third booster pump 9 is connected to the reactor 601. The nitrogen in the nitrogen tank 8 is pumped into the reactor 601 through the third booster pump 9 to control the pressure in the reactor 601 to rise steadily. The reactor 601 is connected to a second stirring motor 602 and a second feeding port 605. The lower end of the reactor 601 is connected to a distillation column 10 through a second discharge valve 603 and a filtering device 7. The filtering device 7 is used to filter the catalyst, and the filtrate enters the distillation column 10. The product outlet of the distillation column 10 is connected to a cyclopentanol tank 12, a solvent tank 13, and a cyclopentene tank 14 through a product pipe 11. The cyclopentanol tank 12, the solvent tank 13, and the cyclopentene tank 14 are all connected to the product pipe 11 through valves 15. The product pipe 11 is connected to a discharge valve 16. The distilled water is discharged through the discharge valve 16 for reuse.

[0021] During the use process, the catalyst is put into the reactor 601 through the second feeding port 605. After steps of heating, vacuum pumping, pressurization, cooling and pressure reduction, during the pressurization process, the second stirring motor 602 operates at a rotational speed of 200 rpm to agitate the catalyst. The first booster pump 3 operates to allow some nitrogen to enter the mixer 101, thereby creating a nitrogen environment inside the mixer 101. The first booster pump 3 is closed, and then cyclopentene, solvent, and water are put into the mixer 101. The first stirring motor 102 operates at a rotational speed of 600 rpm for a mixing time of 120 s. During the cooling and pressure reduction process, the first booster pump 3 operates, and the nitrogen in the reactor 601 enters the mixer 101 to make the pressure inside the mixer 101 the same as that inside the reactor 601. The second booster pump 5 operates to pump the materials in the mixer 101 into the reactor 601. The pressure and temperature of the reactor 601 are adjusted, and the hydration reaction starts. After the reaction is completed, the metering pump 604 operates, and the materials pass through the filtering device 7. The catalyst is filtered, and the filtrate enters the distillation column 10. Through distillation, cyclopentanol, cyclopentene, and solvent are obtained and stored in the corresponding tanks. The cyclopentanol and solvent are recycled.

[0022] Example 1 A method for preparing cyclopentanol by catalytic hydration of cyclopentene, comprising the following steps: Step A, pretreatment of the reactor: Put the catalyst into the reactor. The catalyst is selected as Dowex 50WX2 type cation exchange resin. Heat up to 142 °C, evacuate to 100 Pa, then fill the reactor with nitrogen and pressurize to 2 MPa, maintain for 80 s, relieve pressure to 1 MPa, and cool down to 110 °C. Step B, input of reactants: Mix cyclopentene, solvent, and water and pressurize to 1 MPa, heat up to 110 °C, and then put them into the reactor pretreated in Step A. The solvent is selected as diethylene glycol dimethyl ether. The weight ratio among the catalyst, cyclopentene, solvent, and water is catalyst:cyclopentene: solvent:water = 0.1:1:2:5, and the amount of cyclopentene is 50 Kg. Step C, hydration reaction: Control the reactor temperature at 130 °C and the pressure at 1.5 Mpa, start stirring, and the reaction duration is 5 h. Step D, separation: Control the reactor temperature at 15 °C and the pressure at 0.1 Mpa, filter the catalyst, and distill the filtrate to obtain cyclopentanol. The water and solvent are recycled.

[0023] The test results are shown in Table 1 in the appendix.

[0024] Example 2 A method for preparing cyclopentanol by catalytic hydration of cyclopentene, comprising the following steps: Step A, Reactor Pretreatment: Put a catalyst into the reactor. The catalyst is Dowex 50WX2 type cation exchange resin. Heat up to 145°C, evacuate to 100 Pa, then fill the reactor with nitrogen and increase the pressure to 2 MPa, maintain for 60 s, relieve the pressure to 1 MPa, and cool down to 110°C; Step B, Input Reactants: Mix cyclopentene, solvent, and water, then increase the pressure to 1 MPa and heat up to 110°C. Then put them into the reactor pretreated in Step A. The solvent is diethylene glycol dimethyl ether. The weight ratio among the catalyst, cyclopentene, solvent, and water is: catalyst:cyclopentene: solvent:water = 0.2:1:1.5:4, and the amount of cyclopentene is 50 Kg; Step C, Hydration Reaction: Control the reactor temperature at 135°C and the pressure at 1.5 Mpa, start stirring, and the reaction duration is 4.5 h; Step D, Separation: Control the reactor temperature at 15°C and the pressure at 0.1 Mpa, filter the catalyst, rectify the filtrate to obtain cyclopentanol, and recycle water and the solvent.

[0025] The test results are shown in Appendix 1.

[0026] Example 3 A method for catalytic hydration of cyclopentene to prepare cyclopentanol, comprising the following steps: Step A, Reactor Pretreatment: Put a catalyst into the reactor. The catalyst is Dowex 50WX2 type cation exchange resin. Heat up to 147°C, evacuate to 200 Pa, then fill the reactor with nitrogen and increase the pressure to 2.2 MPa, maintain for 60 s, relieve the pressure to 1.1 MPa, and cool down to 113°C; Step B, Input Reactants: Mix cyclopentene, solvent, and water, then increase the pressure to 1.1 MPa and heat up to 113°C. Then put them into the reactor pretreated in Step A. The solvent is diethylene glycol dimethyl ether. The weight ratio among the catalyst, cyclopentene, solvent, and water is: catalyst:cyclopentene: solvent:water = 0.15:1:1.5:3, and the amount of cyclopentene is 50 Kg; Step C, Hydration Reaction: Control the reactor temperature at 132°C and the pressure at 1.6 Mpa, start stirring, and the reaction duration is 4 h; Step D, Separation: Control the reactor temperature at 20°C and the pressure at 0.1 Mpa, filter the catalyst, rectify the filtrate to obtain cyclopentanol, and recycle water and the solvent.

[0027] The test results are shown in Appendix 1.

[0028] Example 4 A method for catalytic hydration of cyclopentene to prepare cyclopentanol, comprising the following steps: Step A, Reactor Pretreatment: Charge a catalyst into the reactor. The catalyst selected is Dowex 50WX2 type cation exchange resin. Heat up to 143 °C, evacuate to 150 Pa, then fill the reactor with nitrogen and increase the pressure to 2 MPa, maintain for 70 s, relieve the pressure to 1 MPa, and cool down to 110 °C; Step B, Charge Reactants: Mix cyclopentene, solvent, and water and increase the pressure to 1 MPa, heat up to 110 °C, and then charge them into the reactor pretreated in Step A. The solvent selected is diethylene glycol dimethyl ether. The weight ratio among the catalyst, cyclopentene, solvent, and water is catalyst:cyclopentene: solvent:water = 0.1:1:1:4, and the amount of cyclopentene is 50 Kg; Step C, Hydration Reaction: Control the reactor temperature at 135 °C and the pressure at 1.5 Mpa, start stirring, and the reaction duration is 4.5 h; Step D, Separation: Control the reactor temperature at 15 °C and the pressure at 0.1 Mpa, filter the catalyst, rectify the filtrate to obtain cyclopentanol, and recycle water and solvent.

[0029] The test results are shown in Table 1 in the appendix.

[0030] Table 1 in the appendix

[0031] Comparative Example 1: catalyst:cyclopentene: solvent:water = 0.2:1:1.5:4, 50 Kg of cyclopentene. After charging the catalyst, cyclopentene, solvent, and water into the reactor, evacuate to 100 Pa, then fill with nitrogen, control the reactor temperature at 135 °C and the pressure at 1.5 Mpa, start stirring, and the reaction duration is 4.5 h. After the reaction, control the temperature at 15 °C and the pressure at 0.1 MPa, sample the material for separation and testing to obtain the test results.

[0032] It can be obtained from Table 1 in the appendix that first heat up to 142 - 147 °C, which is higher than the reaction temperature, to cause thermal expansion of the catalyst, then evacuate to effectively remove the dissolved gases adsorbed inside and on the surface of the resin, and then increase the pressure to 2 - 2.2 MPa, which is higher than the reaction pressure, and maintain for 60 - 80 s to stabilize the structure of the catalyst. The subsequent catalytic reaction has high selectivity. Compared with directly charging the materials into the reactor for reaction, both the conversion rate and selectivity of cyclopentanol have been greatly improved.

[0033] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing cyclopentanol by catalytic hydration of cyclopentene, characterized in that: The following steps are involved: Step A, reactor pretreatment, adding a catalyst into the reactor, the catalyst is selected from Dowex 50WX2 type cation exchange resin, heating to T1, T1 is 142-147°C, evacuating to P1, P1 is 100-200Pa, then filling nitrogen into the reactor and pressurizing to P2, P2 is 2-2.2MPa, maintaining time t1, t1 is 60-80s, depressurizing to P3, P3 is 1-1.1MPa, cooling to T2, T2 is 110-113°C; Step B, adding reactants, mixing cyclopentene, solvent and water, pressurizing to P3, heating to T2, and then adding to the reactor pretreated in step A, wherein diethylene glycol dimethyl ether is selected as the solvent, and the weight ratio of the catalyst, cyclopentene, solvent and water is catalyst: cyclopentene: solvent: water = 0.1-0.2: 1: 1-2: 3-5; Step C, hydration reaction, control the reactor temperature T4, pressure P4, T4 is 130-135 ° C, P4 is 1.5-1.6Mpa, start stirring, reaction time t2, t2 is 4-5h; Step D, separation, control the reactor temperature T5 and pressure P5, T5 is 15-20°C, P5 is 0.1Mpa, filter the catalyst, distill the filtrate to obtain cyclopentanol, and reuse water and solvent.

2. The method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 1, characterized in that: The particle size of the catalyst is 0.8-1 mm, and the water is deionized water.

3. The method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 1, characterized in that: In step A, T1 is 145°C, P1 is 100 Pa, P2 is 2 MPa, t1 is 60 s, P3 is 1 MPa, and T2 is 110°C.

4. The method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 1, characterized in that: In step B, catalyst: cyclopentene: solvent: water = 0.2: 1: 1.5:

4.

5. The method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 1, characterized in that: In step C, T4 is 135°C, P4 is 1.5Mpa, and t2 is 4.5h.

6. A device for realizing the method for preparing cyclopentanol by catalytic hydration of cyclopentene according to any one of claims 1 to 5, characterized in that: Including mixer, reactor, distillation tower, The mixer is provided with a feeding port 1, an air pipe 1 is provided between the upper end of the reactor and the upper end of the mixer, a booster pump 1 and a three-way valve 1 are provided on the air pipe 1, the outlet end of the booster pump 1 is connected to the mixer, the three-way valve 1 is provided between the booster pump 1 and the mixer 1, one of the ports of the three-way valve 1 is connected to the outside through a filter 1, the lower end of the mixer is connected to the reactor through a booster pump 2, and the outlet end of the booster pump 2 is connected to the reactor; The upper end of the reactor is connected to a nitrogen tank through a second air pipe, a third booster pump is provided on the second air pipe, the outlet end of the third booster pump is connected to the reactor, and the lower end of the reactor is connected to a distillation tower through a filtering device, the filtering device is used to filter the catalyst, and the filtrate enters the distillation tower; The production outlet of the distillation tower is connected to the cyclopentanol tank, the solvent tank and the cyclopentene tank through a production pipe.

7. The device for realizing the method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 6, characterized in that: The booster pump 1 and the booster pump 3 are both air compressors, and the booster pump 2 is a gear pump.

8. The device for realizing the method for preparing cyclopentanol by catalytic hydration of cyclopentene according to claim 6, characterized in that: The outlet end of the second booster pump is connected to the lower end of the reactor, and a metering pump is arranged between the reactor and the filtering device.

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