System and process for preparing cyclohexanol by means of hydration of cyclohexene

Abstract

The present invention relates to the technical field of cyclohexanol production, and in particular to a system and process for preparing cyclohexanol by means of the hydration of cyclohexene. The system for preparing cyclohexanol by means of the hydration of cyclohexene comprises: an alcohol column I, a micro-interface mixing device, a first hydration reactor and a second hydration reactor, wherein the upper middle part of the alcohol column I is in communication with the micro-interface mixing device by means of a side line, and a side line pump is provided on the side line; the micro-interface mixing device is in communication with the first hydration reactor via a first line; the first hydration reactor is in communication with the second hydration reactor via an overflow line and is in communication, at the bottom, with the micro-interface mixing device via a second line; and a slurry pump is provided on the second line. By means of the system for preparing cyclohexanol by means of the hydration of cyclohexene, the technical problem in the prior art of the low conversion rate of cyclohexanol prepared by means of hydration is alleviated, thereby reducing energy consumption.

Description

A system and process for the hydration of cyclohexene to produce cyclohexanol Technical Field

[0001] This invention relates to the field of cyclohexanol production technology, and in particular to a system and process for producing cyclohexanol by hydration of cyclohexene. Background Technology

[0002] The principle of hydration synthesis of cyclohexanol is to partially hydrogenate benzene in the presence of a ruthenium catalyst to obtain cyclohexene (this process is accompanied by the formation of some cyclohexane), and then react cyclohexene with water to obtain cyclohexanol.

[0003] Currently, the conversion rate of cyclohexene to cyclohexanol by hydration is about 9%, and the selectivity is about 99%. In actual production, a large amount of unreacted cyclohexene is constantly circulating in the reaction system, resulting in a slow reaction rate and relatively high energy consumption for the cyclohexene to cyclohexanol production method. Summary of the Invention

[0004] The purpose of this invention is to provide a system and process for the hydration of cyclohexene to produce cyclohexanol, so as to alleviate the technical problem of low conversion rate of hydration to produce cyclohexanol in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the cyclohexene hydration to cyclohexanol system provided by the present invention includes: an alcohol tower, a micro-interface mixing device, a first hydration reactor, and a second hydration reactor.

[0007] The upper and middle parts of the alcohol column are connected to the micro-interface mixing device through a side pipeline, and a side pipeline pump is installed on the side pipeline.

[0008] The micro-interface mixing device is connected to the first hydration reactor via a first pipeline.

[0009] The first hydration reactor is connected to the second hydration reactor via an overflow pipeline, and its bottom is connected to the micro-interface mixing device via a second pipeline.

[0010] A slurry pump is installed on the second pipeline.

[0011] Furthermore, the second hydration reactor is connected to the bottom of the alcohol tower via a third pipeline.

[0012] Furthermore, the side-line pump includes a driving screw, a driven screw, a pump housing, and a rotary motor;

[0013] The driving screw and the driven screw are connected by a drive and mesh with each other. Both are located inside the pump housing and can rotate around their respective axes.

[0014] The pump casing is provided with a first inlet and a first outlet, which are distributed on both sides of the driving screw and the driven screw, and are both directly opposite the meshing point of the driving screw and the driven screw;

[0015] The rotary motor is connected to the active screw drive.

[0016] Furthermore, the side-line pump also includes a first sliding plate, a second sliding plate, and a limiting mechanism;

[0017] The first and second slide plates are parallel to each other and are both located inside the pump housing, with their sides in contact with the inner wall of the pump housing.

[0018] The pump casing is also provided with two second inlets and two second outlets, and each of the two second inlets is provided with an inlet valve and each of the two second outlets is provided with an outlet valve.

[0019] Two second inlets are located outside the first and second slide plates, and two second outlets are also located outside the first and second slide plates;

[0020] One end of both the driving screw and the driven screw is rotatably connected to the first sliding plate, and the other end of both screws is rotatably connected to the second sliding plate.

[0021] One end of the active screw has a first rotating shaft protruding from it, and the limiting mechanism is used to start or release the circumferential fixation between the first rotating shaft and the motor shaft of the rotary motor.

[0022] Furthermore, the motor shaft is a hollow shaft with an open end, and one end of the first rotating shaft is inserted into the motor shaft;

[0023] The limiting mechanism includes a locking rod, a conical cover, and a first drive assembly;

[0024] The locking rod is inserted into the side wall of the motor shaft radially along the motor shaft, with one end outside the motor shaft and embedded with a ball, and the other end used to contact the side wall of the first rotating shaft.

[0025] The locking rod is provided with multiple rods, which are distributed at intervals around the axis of the first rotating shaft;

[0026] The conical cover is fitted onto the motor shaft and covers the locking rod, and is magnetically engaged with the locking rod;

[0027] The first drive assembly is driven to the conical cover to drive the conical cover to slide axially along the motor shaft.

[0028] Furthermore, a cam groove is provided on the side wall of the first rotating shaft;

[0029] A rod is fixed on the motor shaft, the rod extends radially along the first rotating shaft, and its free end is inserted into the cam groove.

[0030] Furthermore, a first gear is coaxially fixed on the first rotating shaft;

[0031] One end of the driven screw has a second rotating shaft protruding from it, and a second gear is coaxially fixed on the second rotating shaft. The second gear meshes with the first gear.

[0032] The limiting mechanism further includes a second drive component, which is configured to limit the rotation of the first gear during startup.

[0033] Furthermore, the side-line pump also includes a flow meter and a control unit;

[0034] The flow meter is used to measure the flow rate at the first inlet or the first outlet.

[0035] The control unit is electrically connected to the flow meter and the rotary motor, respectively.

[0036] Secondly, the cyclohexene hydration to cyclohexanol process provided by the present invention is based on the aforementioned cyclohexene hydration to cyclohexanol system and includes the following steps in sequence:

[0037] S1, the cyclohexene produced by the upstream unit is washed with water and then sent to the alcohol tower.

[0038] S2, the cyclohexene in the upper part of the alcohol tower is transported to the micro-interface mixing device via a side pipeline, and the catalyst at the bottom of the first hydration reactor is transported to the micro-interface mixing device via a second pipeline;

[0039] S3, the cyclohexene and the catalyst are mixed through the micro-interface mixing device, and then the mixture is sent into the first hydration reactor through the first pipeline to carry out the hydration reaction;

[0040] S4, the cyclohexanol generated after the reaction and the remaining cyclohexene are sent to the second hydration reactor through the overflow pipeline for another hydration reaction.

[0041] Furthermore, it also includes the following steps:

[0042] S5, the mixed product in the second hydration reactor is sent to the bottom of the alcohol column through the third pipeline, and then the mixed product is collected from the bottom of the alcohol column and purified. Then the unreacted cyclohexene is sent back to the middle and upper part of the alcohol column.

[0043] Compared with the prior art, the beneficial effects of the cyclohexene hydration to cyclohexanol system provided by the present invention are as follows:

[0044] In this cyclohexene hydration to cyclohexanol system, a side-stream pump transports high-purity cyclohexene from the upper part of the alcohol column to a micro-interface mixing device. A slurry pump extracts the catalyst from the bottom of the first hydration reactor and transports it to the micro-interface mixing device. The micro-interface mixing device disperses the hydrated catalyst slurry and cyclohexene into small particles and droplets. This pre-mixing of the hydrated catalyst slurry and cyclohexene outside the reactor increases the contact area between the materials, enhances the mass transfer process, prolongs the residence time of the materials and catalyst, and thus increases the reaction rate.

[0045] Following the above, the mixed hydrated catalyst slurry and cyclohexene are transported to the first hydration reactor, where they are mixed a second time and then enter the upper grid plate of the first hydration reactor. Here, since the materials are in a relatively static state in the grid plate, cyclohexene separates from the hydrated catalyst slurry under the action of gravity according to their different densities. The hydrated catalyst slurry is then fed back into the micro-interface mixing device by the slurry pump at the bottom of the first hydration reactor. The unreacted cyclohexene and the generated cyclohexanol are sent to the second hydration reactor, where the reaction continues.

[0046] It can be seen that the cyclohexene hydration to cyclohexanol system increases the contact area between cyclohexene, water and catalyst by pre-mixing the hydration catalyst slurry with cyclohexene outside the reactor. This strengthens the mass transfer process and improves the reaction conversion rate.

[0047] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0049] Figure 1 is a schematic diagram of the cyclohexene hydration to cyclohexanol system provided in an embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of the side-line pump provided in an embodiment of the present invention;

[0051] Figure 3 is a schematic diagram of the structure of the side-line pump after removing the pump casing according to an embodiment of the present invention;

[0052] Figure 4 is a schematic diagram of a portion of the structure of the screw pump provided in an embodiment of the present invention;

[0053] Figure 5 is a schematic diagram of a portion of the structure of the piston pump provided in an embodiment of the present invention;

[0054] Figure 6 shows the conversion rate of cyclohexene to cyclohexanol via hydration.

[0055] Icons: 100-Alcohol tower; 200-Micro-interface mixing device; 300-First hydration reactor; 400-Second hydration reactor; 500-Side pipeline; 600-Side line pump; 610-Driving screw; 620-Driven screw; 630-Pump housing; 640-Rotary motor; 650-First slide plate; 660-Second slide plate; 670-Limiting mechanism; 680-Inlet pipe; 690-Outlet pipe; 611-First shaft; 612-First gear; 621-Second shaft; 622-Second gear; 641-Motor shaft; 642-Insertion rod; 671-Locking rod; 672-Conical cover; 673-First cylinder; 674-Second cylinder; 675-Clamping block; 676-Cylinder body; 677-Electric telescopic rod; 6111-Cam groove; 700 - First pipeline; 800 - Overflow pipeline; 900 - Second pipeline; 1000 - Slurry pump; 1100 - Third pipeline. Detailed Implementation

[0056] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0058] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0059] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0060] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0062] Currently, the conversion rate of cyclohexene to cyclohexanol by hydration is about 9%, and the selectivity is about 99%. In actual production, a large amount of unreacted cyclohexene is constantly circulating in the reaction system, resulting in a slow reaction rate and relatively high energy consumption for the cyclohexene to cyclohexanol production method.

[0063] In view of this, embodiments of the present invention provide a cyclohexene hydration to cyclohexanol system. Referring to Figure 1, the cyclohexene hydration to cyclohexanol system includes: an alcohol tower 100, a micro-interface mixing device 200, a first hydration reactor 300, and a second hydration reactor 400; the upper middle part of the alcohol tower 100 is connected to the micro-interface mixing device 200 via a side pipeline 500, and a side pipeline pump 600 is installed on the side pipeline 500; the micro-interface mixing device 200 is connected to the first hydration reactor 300 via a first pipeline 700; the first hydration reactor 300 is connected to the second hydration reactor 400 via an overflow pipeline 800, and its bottom is connected to the micro-interface mixing device 200 via a second pipeline 900; a slurry pump 1000 is installed on the second pipeline 900.

[0064] In this cyclohexene hydration to cyclohexanol system, a side-stream pump 600 transports high-purity cyclohexene from the upper part of the alcohol tower 100 to a micro-interface mixing device 200. A slurry pump 1000 extracts the catalyst from the bottom of the first hydration reactor 300 and transports it to the micro-interface mixing device 200. The micro-interface mixing device 200 disperses the hydrated catalyst slurry and cyclohexene into small particles and droplets. This completes the pre-mixing of the hydrated catalyst slurry and cyclohexene outside the reactor, increasing the contact area of ​​the materials, enhancing the mass transfer process, prolonging the residence time of the materials and catalyst, and thus increasing the reaction rate.

[0065] Following the above, the mixed hydrated catalyst slurry and cyclohexene are transported to the first hydration reactor 300, where they are mixed a second time and then enter the upper grid plate of the first hydration reactor 300. Here, since the materials are in a relatively static state in the grid plate, cyclohexene and hydrated catalyst slurry separate under the action of gravity according to their different densities. The hydrated catalyst slurry is then fed back into the micro-interface mixing device 200 by the slurry pump 1000 at the bottom of the first hydration reactor 300. The unreacted cyclohexene and the generated cyclohexanol are sent to the second hydration reactor 400, where the reaction continues.

[0066] It can be seen that the cyclohexene hydration to cyclohexanol system increases the contact area between cyclohexene, water and catalyst by pre-mixing the hydration catalyst slurry with cyclohexene outside the reactor. This strengthens the mass transfer process and improves the reaction conversion rate.

[0067] Furthermore, referring to Figure 1, the second hydration reactor 400 is connected to the bottom of the alcohol column 100 via a third pipeline 1100. After the materials complete the reaction in the second hydration reactor 400, cyclohexene and cyclohexanol are collected from the bottom of the alcohol column 100 and sent to the distillation system for further purification. Unreacted cyclohexene is returned to the alcohol column 100 and sent back to the micro-interface mixing device 200 via a side-stream pump 600.

[0068] Regarding the side-line pump 600, specifically:

[0069] In the production of cyclohexanol, there is a problem of pump corrosion. Based on this, in this embodiment, the side-stream pump 600 has the functions of both a twin-screw pump and a piston pump.

[0070] When the screw of a twin-screw pump is corroded, its surface becomes rough and its dimensions change, resulting in a decrease in conveying capacity and an increase in fluid flow resistance. At this time, the flow rate of the twin-screw pump will decrease. When the flow rate of the twin-screw pump is detected to drop to the set value, the pump is switched to a piston pump to ensure that the current production continues normally, while preventing further damage to the twin-screw pump and facilitating subsequent maintenance.

[0071] In this embodiment, referring to Figures 2 to 5, the side-line pump 600 includes a driving screw 610, a driven screw 620, a pump housing 630, a rotary motor 640, and a limiting mechanism 670. The driving screw 610 and the driven screw 620 are arranged parallel to each other within the pump housing 630 to form a twin-screw pump. The driving screw 610 is coaxially arranged with and fixedly connected to the first rotating shaft 611, and the two can also be integrally formed. A first gear 612 is coaxially fixed on the first rotating shaft 611. Similarly, the driven screw 620 is coaxially arranged with and fixedly connected to the second rotating shaft 621, and the two can also be integrally formed. A second gear 622 is coaxially fixed on the second rotating shaft 621, and the second gear 622 meshes with the first gear 612. The second gear 622 and the first gear 612 are located within a housing, which is slidably installed on the pump housing 630 via a linear guide rail or other connection method. The pump housing 630 is provided with a first inlet and a first outlet.

[0072] As described above, the motor shaft 641 of the rotary motor 640 is a hollow shaft with an open free end, and one end of the first rotating shaft 611 is inserted into the motor shaft 641; the limiting mechanism 670 includes a locking rod 671, a conical cover 672, and a first drive assembly; the locking rod 671 is inserted into the side wall of the motor shaft 641 radially along the motor shaft 641, with one end outside the motor shaft 641 and embedded with a ball, and the other end is used to contact the side wall of the first rotating shaft 611; multiple locking rods 671 are provided, and the multiple locking rods 671 are distributed at intervals around the axis of the first rotating shaft 611; the conical cover 672 is sleeved on the motor shaft 641 and covers the locking rod 671, and is magnetically engaged with the locking rod 671; the first drive assembly is drivenly connected to the conical cover 672 to drive the conical cover 672 to slide axially along the motor shaft 641.

[0073] Referring to Figures 2, 3, and 5, when the side-line pump 600 operates as a twin-screw pump, the first drive assembly drives the conical cover 672 to move away from the rotary motor 640 body, causing the inner wall of the conical cover 672 to abut against the ball bearings, thereby causing multiple locking rods 671 to abut against the side of the first rotating shaft 611. Here, to increase torque transmission, patterns or other structures can be provided on the surfaces where the locking rods 671 contact the first rotating shaft 611 to increase friction. During operation, the rotary motor 640 drives the motor shaft 641 to rotate around its own axis, which in turn drives the first rotating shaft 611 to rotate around its own axis via the locking rods 671, thereby causing the drive screw 610 to rotate. Simultaneously, under the transmission of the first gear 612 and the second gear 622, the driven screw 620 rotates synchronously. Fluid enters the pump casing 630 through the first inlet and is discharged from the first outlet under the transmission of the drive screw 610 and the driven screw 620.

[0074] In this embodiment, referring to Figures 3 and 5, the side-line pump 600 further includes a first slide plate 650 and a second slide plate 660. The first slide plate 650 and the second slide plate 660 are parallel to each other and are both located inside the pump housing 630, with their sides fitting against the inner wall of the pump housing 630. The pump housing 630 is also provided with two second inlets and two second outlets, with inlet valves at the two second inlets and outlet valves at the two second outlets. The two second inlets are located outside the first slide plate 650 and the second slide plate 660, and the two second outlets are also located outside the first slide plate 650 and the second slide plate 660. One end of the driving screw 610 and the driven screw 620 are rotatably connected to the first slide plate 650, and the other end is rotatably connected to the second slide plate 660. Here, the driving screw 610, the driven screw 620, the first slide plate 650, and the second slide plate 660 constitute the piston of the piston pump.

[0075] As described above, a cam groove 6111 is provided on the side wall of the first rotating shaft 611; a plug rod 642 is fixed on the motor shaft 641, the plug rod 642 extends radially along the first rotating shaft 611, and its free end is inserted into the cam groove 6111.

[0076] Referring to Figures 2, 3, and 5, when the side-line pump 600 operates as a piston pump, under the drive of the first drive assembly, the conical cover 672 moves towards the body of the rotary motor 640. Under magnetic attraction, each locking rod 671 slides radially outward along the first rotating shaft 611, disengaging from the first rotating shaft 611. At this time, when the rotary motor 640 is running, it will not drive the driving screw 610 and the driven screw 620 to rotate, but will drive the insertion rod 642 to rotate around the axis of the motor shaft 641. With the cooperation of the insertion rod 642 and the cam groove 6111, the first rotating shaft 611 will reciprocate along its own axial direction, thereby driving the piston to reciprocate within the pump housing 630. In this way, the function of the piston pump is realized, allowing fluid to enter through the second inlet and exit through the second outlet. It should also be noted that when the piston slides, the first gear 612, the second gear 622, and the housing also slide synchronously.

[0077] Furthermore, the limiting mechanism 670 also includes a second drive assembly configured to restrict the rotation of the first gear 612 during startup. This design ensures that the insertion rod 642 does not drive the first rotating shaft 611 to rotate when it rotates, allowing effective sliding between the insertion rod 642 and the cam groove 6111.

[0078] In this embodiment, the side-line pump 600 also includes a flow meter and a control unit; the flow meter is used to measure the flow rate at the first inlet or the first outlet; the control unit is electrically connected to the flow meter and the rotary motor 640 respectively.

[0079] Specifically, referring to Figures 2, 3 and 5, the pump housing 630 is fixed with an inlet pipe 680 and an outlet pipe 690. The inlet pipe 680 has one inlet and three outlets, and the outlet pipe 690 has three inlets and one outlet. The three outlets of the inlet pipe 680 are connected to the first inlet and the second inlet, respectively, and the three inlets of the outlet pipe 690 are connected to the first outlet and the second outlet, respectively.

[0080] As described above, the first drive assembly includes a first cylinder 673 and a connecting frame, the second drive assembly includes a second cylinder 674 and a locking block 675; the control unit includes a controller and an electric telescopic rod 677.

[0081] Continuing from the above, the conical cover 672 is connected to the connecting frame, the first cylinder 673 is installed on the pump housing 630, and the output end of the first cylinder 673 is connected to the connecting frame to drive the conical cover 672 to move along its own axis on the motor shaft 641; the second cylinder 674 is installed on the housing, and the locking block 675 is connected to the output end of the second cylinder 674, and the second cylinder 674 extends to drive the locking block 675 to engage with the first gear 612; the electric telescopic rod 677 is located inside the cylinder 676, and the piston plate at its output end divides the inner cavity of the cylinder 676 into an upper cavity and a lower cavity, and the cylinder 676 is fixed to the pump housing 630; the upper cavity is connected to the first cylinder 673, and the lower cavity is connected to the second cylinder 674.

[0082] When the side-line pump 600 is to operate as a twin-screw pump, as shown in Figures 3 and 5, the electric telescopic rod 677 drives the piston plate upward to compress the upper chamber, supplying pressure to the first cylinder 673. At this time, the output end of the first cylinder 673 extends, driving the connecting frame and the conical cover 672 to move closer to the housing, thereby causing the conical cover 672 to press against the locking rod 671, making the locking rod 671 abut against the camshaft. At this time, the rotary motor 640 can drive the driving screw 610 and the driven screw 620 to rotate around their respective axes. Here, when the first cylinder 673 extends, the second cylinder 674 retracts accordingly, causing the locking block 675 to move away from the first gear 612, thereby ensuring the normal rotation of the first gear 612, the first rotating shaft 611, and the driving screw 610.

[0083] When switching to piston pump mode is required, the electric telescopic rod 677 drives the piston plate to move downward, compressing the lower chamber to supply pressure to the second cylinder 674. At this time, the output end of the first cylinder 673 retracts, and the output end of the second cylinder 674 extends. As a result, the conical cover 672 moves away from the housing, causing the locking rod 671 to disengage from the first rotating shaft 611. At the same time, the locking block 675 engages with the first gear 612, ensuring that the first gear 612 cannot rotate. At this time, the rotary motor 640 can drive the first rotating shaft 611 to reciprocate along its own axis, thereby causing the piston to slide back and forth within the pump housing 630.

[0084] When the side line pump 600 operates as a twin-screw pump, the controller obtains the rotational speed of the rotary motor 640 and the flow meter reading to determine whether the driving screw 610 and driven screw 620 are corroded. If the flow rate is low at a specific rotational speed of the rotary motor 640, it indicates that the driving screw 610 and driven screw 620 are corroded. At this time, the controller controls the electric telescopic rod 677 to start, supplying pressure to the second cylinder 674, causing the side line pump 600 to switch to piston pump mode, ensuring the normal operation of the side line pump 600.

[0085] This invention also provides a process for the hydration of cyclohexene to produce cyclohexanol. This process, based on a cyclohexene hydration to cyclohexanol system, includes the following steps:

[0086] S1. Cyclohexene produced by the upstream unit is washed with water and fed into alcohol tower 100. S2. Cyclohexene in the upper part of alcohol tower 100 is transported to micro-interface mixing device 200 via side pipeline 500, and catalyst at the bottom of the first hydration reactor 300 is transported to micro-interface mixing device 200 via second pipeline 900. S3. Cyclohexene and catalyst are mixed in micro-interface mixing device 200, and then the mixture is sent to the first hydration reactor 300 via first pipeline 700 for hydration reaction. S4. Cyclohexanol and the remaining cyclohexene generated after the reaction are sent to the second hydration reactor 400 via overflow pipeline 800 for hydration reaction again. S5. The mixed product in the second hydration reactor 400 is sent to the bottom of alcohol tower 100 via third pipeline 1100, and the mixed product is collected and purified from the bottom of alcohol tower 100. Then, the unreacted cyclohexene is sent back to the upper part of alcohol tower 100.

[0087] In the above process, a small amount of light components in cyclohexene (approximately 95% purity) are collected from the top of alcohol column 100 and returned to the upstream unit. The higher purity cyclohexene (approximately 97% purity) in the upper part of alcohol column 100 is transported to the micro-interface mixing device 200 via side-line pump 600, where it is thoroughly mixed with the catalyst (aluminosilicate) collected from the bottom of the first hydration reactor 300, and then fed into the first hydration reactor 300 together. Part of the cyclohexene reacts with water in the first hydration reactor 300 to produce cyclohexanol, and then the cyclohexanol and the remaining cyclohexene are sent to the second hydration reactor 400 via overflow line 800 for further reaction. Finally, the cyclohexanol produced by the reaction is collected from the bottom of alcohol column 100 and sent to the distillation system for further purification, while the unreacted cyclohexene is returned to alcohol column 100 and sent to the hydration reactor for further reaction.

[0088] The following specific embodiment illustrates the process for producing cyclohexanol from cyclohexene hydration provided by the present invention:

[0089] The hydration reactor in the cyclohexanone workshop was officially put into operation at 7:00 AM on July 26, 2024, after a major overhaul. Two hydration reactors, A and B, were set up. Reactor A was the experimental group, using the cyclohexene hydration to cyclohexanol process provided by this invention, while reactor B was the control group, using the existing process. Both reactors operated at the same load. Operational data were collected from July 27, 2024, to August 14, 2024, after startup, as shown in Figure 6.

[0090] The operational data after the overhaul shows that the overall performance of the hydration reaction in unit A is better than that in unit B. This means that the reaction conversion rate can be improved by mixing the hydration catalyst slurry with cyclohexene outside the reactor in advance.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for the hydration of cyclohexene to produce cyclohexanol, characterized in that, include: An alcohol tower (100), a micro-interface mixing device (200), a first hydration reactor (300), and a second hydration reactor (400); The upper middle part of the alcohol tower (100) is connected to the micro-interface mixing device (200) through a side pipeline (500), and a side pipeline pump (600) is provided on the side pipeline (500). The micro-interface mixing device (200) is connected to the first hydration reactor (300) via a first pipeline (700); The first hydration reactor (300) is connected to the second hydration reactor (400) via an overflow pipeline (800), and its bottom is connected to the micro-interface mixing device (200) via a second pipeline (900). A slurry pump (1000) is installed on the second pipeline (900).

2. The cyclohexene hydration to cyclohexanol system according to claim 1, characterized in that, The second hydration reactor (400) is connected to the bottom of the alcohol tower (100) via a third pipeline (1100).

3. The cyclohexene hydration to cyclohexanol system according to claim 1, characterized in that, The side-line pump (600) includes a driving screw (610), a driven screw (620), a pump housing (630), and a rotary motor (640); The driving screw (610) and the driven screw (620) are connected in a transmission and mesh with each other. They are both located inside the pump housing (630) and can rotate around their respective axes. The pump housing (630) is provided with a first inlet and a first outlet. The first inlet and the first outlet are distributed on both sides of the driving screw (610) and the driven screw (620), and are both directly opposite the meshing point of the driving screw (610) and the driven screw (620). The rotary motor (640) is connected to the drive screw (610) for transmission.

4. The cyclohexene hydration to cyclohexanol system according to claim 3, characterized in that, The side-line pump (600) also includes a first sliding plate (650), a second sliding plate (660), and a limiting mechanism (670); The first slide plate (650) and the second slide plate (660) are parallel to each other and are both located inside the pump housing (630), and their sides are in contact with the inner wall of the pump housing (630). The pump casing (630) is also provided with two second inlets and two second outlets, and each of the two second inlets is provided with an inlet valve and each of the two second outlets is provided with an outlet valve. Two second inlets are located outside the first slide plate (650) and the second slide plate (660), and two second outlets are also located outside the first slide plate (650) and the second slide plate (660); One end of both the driving screw (610) and the driven screw (620) is rotatably connected to the first sliding plate (650), and the other end is rotatably connected to the second sliding plate (660); One end of the active screw (610) has a first rotating shaft (611) protruding out, and the limiting mechanism (670) is used to start or release the circumferential fixation between the first rotating shaft (611) and the motor shaft (641) of the rotary motor (640).

5. The cyclohexene hydration to cyclohexanol system according to claim 4, characterized in that, The motor shaft (641) is a hollow shaft with an open end, and one end of the first rotating shaft (611) is inserted into the motor shaft (641); The limiting mechanism (670) includes a locking lever (671), a conical cover (672), and a first drive assembly; The locking rod (671) is inserted into the side wall of the motor shaft (641) radially along the motor shaft (641), with one end outside the motor shaft (641) and embedded with a ball, and the other end is used to contact the side wall of the first rotating shaft (611). The locking rod (671) is provided with multiple rods, which are distributed at intervals around the axis of the first rotating shaft (611); The conical cover (672) is sleeved on the motor shaft (641) and covers the locking rod (671), and is magnetically engaged with the locking rod (671); The first drive assembly is connected to the conical cover (672) to drive the conical cover (672) to slide along the axial direction of the motor shaft (641).

6. The cyclohexene hydration to cyclohexanol system according to claim 5, characterized in that, The first rotating shaft (611) has a cam groove (6111) on its side wall; A rod (642) is fixed on the motor shaft (641). The rod (642) extends radially along the first rotating shaft (611), and its free end is inserted into the cam groove (6111).

7. The cyclohexene hydration to cyclohexanol system according to claim 6, characterized in that, A first gear (612) is coaxially fixed on the first rotating shaft (611); One end of the driven screw (620) has a protruding second shaft (621), and a second gear (622) is coaxially fixed on the second shaft (621). The second gear (622) meshes with the first gear (612). The limiting mechanism (670) further includes a second drive component configured to limit the rotation of the first gear (612) during startup.

8. The cyclohexene hydration to cyclohexanol system according to claim 7, characterized in that, The side-line pump (600) also includes a flow meter and a control unit; The flow meter is used to measure the flow rate at the first inlet or the first outlet. The control unit is electrically connected to the flow meter and the rotary motor (640), respectively.

9. A process for the synthesis of cyclohexanol by cyclohexene hydration, characterized in that, The cyclohexene hydration to cyclohexanol system according to any one of claims 1 to 8 comprises the following steps: S1, the cyclohexene produced by the upstream unit is washed with water and then sent to the alcohol tower (100); S2, the cyclohexene in the upper part of the alcohol tower (100) is transported to the micro-interface mixing device (200) via the side pipeline (500), and the catalyst at the bottom of the first hydration reactor (300) is transported to the micro-interface mixing device (200) via the second pipeline (900). S3, the cyclohexene and the catalyst are mixed by the micro-interface mixing device (200), and then the mixture is sent into the first hydration reactor (300) through the first pipeline (700) for hydration reaction; S4, the cyclohexanol generated after the reaction and the remaining cyclohexene are sent to the second hydration reactor (400) through the overflow line (800) for another hydration reaction.

10. The process for hydrating cyclohexene to produce cyclohexanol according to claim 9, characterized in that, It also includes the following steps: S5, the mixed product in the second hydration reactor (400) is sent to the bottom of the alcohol column (100) through the third pipeline (1100), and the mixed product is then collected from the bottom of the alcohol column (100) and purified. Then the unreacted cyclohexene is sent back to the middle and upper part of the alcohol column (100).

Images