System and process for preparing cyclohexanol by cyclohexene hydration

Abstract

The invention relates to the technical field of cyclohexanol production, in particular to a system and a process for preparing cyclohexanol by cyclohexene hydration. The system for preparing cyclohexanol through cyclohexene hydration comprises an alcohol tower I, a micro-interface mixing device, a first hydration reactor and a second hydration reactor, the middle upper part of the alcohol I tower is communicated with the micro-interface mixing device through a side pipeline, and a side line pump is arranged on the side pipeline; the micro-interface mixing device is communicated with the first hydration reactor through a first pipeline; the first hydration reactor is communicated with the second hydration reactor through an overflow pipeline, and the bottom of the first hydration reactor is communicated with the micro-interface mixing device through a second pipeline; and a slurry pump is arranged on the second pipeline. According to the system for preparing cyclohexanol by hydrating cyclohexene, the technical problem of low conversion rate of cyclohexanol prepared by hydrating in the prior art is relieved, and the energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of cyclohexanol production, and in particular to a cyclohexene hydration system and process for producing cyclohexanol. Background Art

[0002] The principle of producing cyclohexanol by the hydration method is that benzene is partially hydrogenated to produce cyclohexene under the action of a ruthenium-based catalyst (this process is accompanied by the formation of some cyclohexane), and then cyclohexene reacts with water to produce cyclohexanol.

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

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

[0005] In order to solve the above technical problems, the technical solution provided by the present invention lies in:

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

[0007] The middle upper part of the alcohol first tower is communicated with the micro-interface mixing device through a side pipeline, and a side line pump is arranged on the side pipeline;

[0008] The micro-interface mixing device is communicated with the first hydration reactor through a first pipeline;

[0009] The first hydration reactor is communicated with the second hydration reactor through an overflow pipeline, and its bottom is communicated with the micro-interface mixing device through a second pipeline;

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

[0011] Further, the second hydration reactor is communicated with the bottom of the alcohol first tower through a third pipeline.

[0012] Further, the side line pump includes a driving screw, a driven screw, a pump casing, and a rotating motor;

[0013] The driving screw is in transmission connection with the driven screw, and the two are meshed with each other, and both are arranged in the pump casing and can rotate around their respective axes;

[0014] The pump housing is provided with a first inlet and a first outlet, and the first inlet and the first outlet are distributed on both sides of the driving screw and the driven screw, and both are facing the meshing position of the driving screw and the driven screw;

[0015] The rotating motor is in transmission connection with the driving screw.

[0016] Furthermore, the side line pump further includes a first slide plate, a second slide plate and a limiting mechanism;

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

[0018] The pump housing is further provided with two second inlets and two second outlets, and water inlet valves are respectively arranged at the two second inlets, and water outlet valves are respectively arranged at the two second outlets;

[0019] The two second inlets are distributed outside the first slide plate and the second slide plate, and the two second outlets are also distributed outside the first slide plate and the second slide plate;

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

[0021] One end of the driving screw protrudes with a first rotating shaft, and the limiting mechanism is used to start or release the circumferential fixation between the first rotating shaft and the motor shaft of the rotating motor.

[0022] Furthermore, the motor shaft is a hollow shaft with an open end at the free 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 driving component;

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

[0025] There are multiple locking rods, and the multiple locking rods are distributed at intervals around the axis of the first rotating shaft;

[0026] The conical cover is sleeved on the motor shaft and covers the locking rod, and is magnetically matched with the locking rod;

[0027] The first driving component is in transmission connection with the conical cover to drive the conical cover to slide axially along the motor shaft.

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

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

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

[0031] One end of the driven screw protrudes with a second rotating shaft, a second gear is coaxially fixed on the second rotating shaft, and the second gear meshes with the first gear;

[0032] The limiting mechanism further includes a second driving component, and the second driving component is configured to limit the rotation of the first gear under the starting condition.

[0033] Further, the side line pump further 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 rotating motor respectively.

[0036] In a second aspect, the cyclohexene hydration process for producing cyclohexanol provided by the present invention is based on the cyclohexene hydration system for producing cyclohexanol, and sequentially includes the following steps:

[0037] S1, the cyclohexene produced by the upstream unit is sent to the first alcohol tower after being washed with water;

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

[0039] S3, the cyclohexene and the catalyst are mixed by the microinterface mixing device, and then the mixture is sent into the first hydration reactor through a first pipeline for hydration reaction;

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

[0041] Further, the following steps are further included:

[0042] S5, the mixed product in the second hydration reactor is sent to the bottom of the first alcohol tower through a third pipeline, the mixed product is extracted and purified from the bottom of the first alcohol tower, and then the unreacted cyclohexene is sent into the upper middle part of the first alcohol tower again.

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

[0044] In this cyclohexene hydration system for producing cyclohexanol, through a side line pump, the relatively high-purity cyclohexene in the upper-middle part of the first alcohol column is transported to the microinterface mixing device, and through a slurry pump, the catalyst at the bottom of the first hydration reactor is pumped out and transported to the microinterface mixing device; the microinterface mixing device disperses the hydration catalyst slurry and cyclohexene into small particles and small droplets. In this way, the premixing of the hydration catalyst slurry and cyclohexene outside the reactor is completed, increasing the contact area of the materials, strengthening the mass transfer process, and prolonging the residence time of the materials and the catalyst, thereby increasing the reaction rate.

[0045] Subsequently, the mixed hydration catalyst slurry and cyclohexene are transported to the first hydration reactor, where they are mixed again and enter the upper grid plate of the first hydration reactor. Here, since the materials are in a relatively static state in the grid plate, according to the different densities, under the action of gravity, cyclohexene and the hydration catalyst slurry are separated. The hydration catalyst slurry is re-sent to the microinterface mixing device through the slurry pump at the bottom of the first hydration reactor, and the unreacted cyclohexene and the produced cyclohexanol are sent to the second hydration reactor for continuous reaction.

[0046] It can be seen that this cyclohexene hydration system for producing cyclohexanol premixes the hydration catalyst slurry and cyclohexene outside the reactor, increasing the contact area of cyclohexene, water, and the catalyst. In this way, the mass transfer process is strengthened, and the reaction conversion rate can be improved.

[0047] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the related art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0049] Figure 1 It is a schematic diagram of the cyclohexene hydration system for producing cyclohexanol provided by the embodiment of the present invention;

[0050] Figure 2 It is a schematic diagram of the structure of the side line pump provided by the embodiment of the present invention;

[0051] Figure 3 It is a schematic diagram of the structure of the side line pump after removing the pump casing provided by the embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of a partial structure of the screw pump provided by the embodiment of the present invention;

[0053] Figure 5 It is a schematic diagram of a partial structure of the piston pump provided by the embodiment of the present invention;

[0054] Figure 6 It is a data table of the conversion rate of cyclohexene hydration to cyclohexanol.

[0055] Icon:

[0056] 100 - Alcohol First Tower; 200 - Micro - interface Mixing Device; 300 - First Hydration Reactor; 400 - Second Hydration Reactor; 500 - Side Pipeline;

[0057] 600 - Side - line Pump; 610 - Driving Screw; 620 - Driven Screw; 630 - Pump Housing; 640 - Rotating Motor; 650 - First Slide Plate; 660 - Second Slide Plate; 670 - Limiting Mechanism; 680 - Liquid Inlet Pipe; 690 - Liquid Outlet Pipe; 611 - First Rotating Shaft; 612 - First Gear; 621 - Second Rotating Shaft; 622 - Second Gear; 641 - Motor Shaft; 642 - Plug Rod; 671 - Locking Rod; 672 - Conical Cover; 673 - First Cylinder; 674 - Second Cylinder; 675 - Block; 676 - Cylinder Body; 677 - Electric Telescopic Rod; 6111 - Cam Groove;

[0058] 700 - First Pipeline; 800 - Overflow Pipeline; 900 - Second Pipeline; 1000 - Slurry Pump; 1100 - Third Pipeline. Detailed Embodiment

[0059] Next, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0060] It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0061] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. For the physical quantities in the formulas, unless otherwise specifically marked, they should be understood as the basic quantities of the basic units in the International System of Units, or the derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0062] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only 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 inclined.

[0063] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" 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 circumstances.

[0064] The following will describe in detail some embodiments of the present invention with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0065] At present, the conversion rate of cyclohexene hydration to cyclohexanol is about 9%, and the selectivity is about 99%. During the actual production process, a large amount of unreacted cyclohexene is always circulating in the reaction system, resulting in a relatively slow reaction rate and relatively high energy consumption for the cyclohexene hydration to cyclohexanol reaction.

[0066] In view of this, the 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 first tower 100, a microinterface mixing device 200, a first hydration reactor 300, and a second hydration reactor 400; the middle-upper part of the alcohol first tower 100 is connected to the microinterface mixing device 200 through a side pipeline 500, and a side-line pump 600 is arranged on the side pipeline 500; the microinterface mixing device 200 is connected to the first hydration reactor 300 through a first pipeline 700; the first hydration reactor 300 is connected to the second hydration reactor 400 through an overflow pipeline 800, and its bottom is connected to the microinterface mixing device 200 through a second pipeline 900; a slurry pump 1000 is arranged on the second pipeline 900.

[0067] In this cyclohexene hydration to cyclohexanol system, through the side-line pump 600, the cyclohexene with higher purity in the middle-upper part of the alcohol first tower 100 is transported to the microinterface mixing device 200, and through the slurry pump 1000, the catalyst at the bottom of the first hydration reactor 300 is extracted and transported to the microinterface mixing device 200; the microinterface mixing device 200 disperses the hydration catalyst slurry and cyclohexene into small particles and small droplets. In this way, the premixing of the hydration catalyst slurry and cyclohexene outside the reactor is completed, increasing the contact area of the materials, strengthening the mass transfer process, prolonging the residence time of the materials and the catalyst, and thus increasing the reaction rate.

[0068] Continuing from the above, the mixed hydration catalyst slurry and cyclohexene are transported to the first hydration reactor 300 and are mixed again in the first hydration reactor 300, and 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, according to the different densities, under the action of gravity, cyclohexene is separated from the hydration catalyst slurry. The hydration catalyst slurry is re-sent to the microinterface mixing device 200 through the slurry pump 1000 at the bottom of the first hydration reactor 300, and the unreacted cyclohexene and the generated cyclohexanol are sent to the second hydration reactor 400 for continuous reaction.

[0069] It can be seen that this cyclohexene hydration to cyclohexanol system premixes the hydration catalyst slurry and cyclohexene outside the reactor, increasing the contact area of cyclohexene, water and the catalyst. In this way, the mass transfer process is strengthened and the reaction conversion rate can be improved.

[0070] Furthermore, referring to Figure 1 , the second hydration reactor 400 is connected to the bottom of the alcohol first tower 100 through a third pipeline 1100. After the materials complete the reaction in the second hydration reactor 400, cyclohexene and cyclohexanol are taken out from the bottom of the alcohol first tower 100 to the distillation system for further purification, and the unreacted cyclohexene is returned to the alcohol first tower 100 and sent to the microinterface mixing device 200 again through the side-line pump 600.

[0071] Regarding the sideline pump 600, specifically:

[0072] In the production of cyclohexanol, there is a problem of corrosion of the pump. Based on this, in this embodiment, the side line pump 600 has the functions of a twin-screw pump and a piston pump.

[0073] When the screw of a twin-screw pump is corroded, its surface becomes rough and its size changes, resulting in decreased conveying capacity and increased fluid flow resistance. At this time, the flow rate of the twin-screw pump will decrease. When it is detected that the flow rate of the twin-screw pump has dropped to the set value, it switches to the piston pump to ensure the normal operation of the current production, while avoiding further damage to the twin-screw pump, which is conducive to subsequent maintenance.

[0074] In this embodiment, reference Figures 2 to 5 The side line pump 600 includes an active screw 610, a driven screw 620, a pump housing 630, a rotating motor 640 and a limiting mechanism 670; the active screw 610 and the driven screw 620 are arranged in parallel in the pump housing 630 to form a twin-screw pump, the active screw 610 is coaxially arranged with the first rotating shaft 611 and fixedly connected, and the two can also be integrally processed, and a first gear 612 is coaxially fixed on the first rotating shaft 611; similarly, the driven screw 620 is coaxially arranged with the second rotating shaft 621 and fixedly connected, and the two can also be integrally processed, and a second gear 622 is coaxially fixed on the second rotating shaft 621, and the second gear 622 is meshed with the first gear 612; the second gear 622 and the first gear 612 are in the box shell, and the box shell is slidably installed on the pump housing 630 by connecting methods such as linear guides; a first inlet and a first outlet are provided on the pump housing 630.

[0075] In accordance with the above, the motor shaft 641 of the rotating 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 driving assembly; the locking rod 671 is inserted into the side wall of the motor shaft 641 along the radial direction of the motor shaft 641, and one end of the locking rod 671 is outside the motor shaft 641 and is embedded with a ball, and the other end is used to contact the side wall of the first rotating shaft 611; there are multiple locking rods 671, 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 is covered on the locking rod 671, and is magnetically matched with the locking rod 671; the first driving assembly is transmission connected to the conical cover 672 to drive the conical cover 672 to slide along the axial direction of the motor shaft 641.

[0076] Combination Figure 2 , Figure 3 and Figure 5As shown, when the side-line pump 600 operates in the state of a twin-screw pump, the first driving assembly drives the conical cover 672 to move away from the body of the rotary motor 640, so that the inner wall of the conical cover 672 abuts against the balls, and then a plurality of locking rods 671 abut against the side surface of the first rotating shaft 611. Here, to increase torque transmission, structures such as patterns can be provided on the contact surface between the locking rod 671 and 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, and then drives the first rotating shaft 611 to rotate around its own axis through the locking rod 671, so that the driving screw 610 rotates. At the same time, under the transmission of the first gear 612 and the second gear 622, the driven screw 620 rotates synchronously. The fluid enters the pump housing 630 through the first inlet and is discharged from the first outlet under the transmission of the driving screw 610 and the driven screw 620.

[0077] In this embodiment, referring to Figure 3 and Figure 5 , the side-line pump 600 further includes a first sliding plate 650 and a second sliding plate 660; the first sliding plate 650 and the second sliding plate 660 are parallel to each other, both are located in the pump housing 630, and the sides of both are attached to the inner wall of the pump housing 630; there are also two second inlets and two second outlets on the pump housing 630, and water inlet valves are respectively provided at the two second inlets, and water outlet valves are respectively provided at the two second outlets; the two second inlets are distributed outside the first sliding plate 650 and the second sliding plate 660, and the two second outlets are also distributed outside the first sliding plate 650 and the second sliding 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 of both is rotatably connected to the second sliding plate 660. Here, the driving screw 610, the driven screw 620, the first sliding plate 650 and the second sliding plate 660 form the piston of the piston pump.

[0078] Continuing from the 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, and the plug rod 642 extends along the radial direction of the first rotating shaft 611, and its free end is inserted into the cam groove 6111.

[0079] Combined with Figure 2 , Figure 3 and Figure 5As shown, when the side pump 600 operates in the piston pump state, under the drive of the first drive assembly, the conical cover 672 moves towards the direction close to the body of the rotary motor 640. Under the magnetic attraction, each locking rod 671 slides radially outward along the first rotating shaft 611 and disengages from the first rotating shaft 611. At this time, when the rotary motor 640 operates, 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. Under the cooperation of the insertion rod 642 and the cam groove 6111, the first rotating shaft 611 will slide reciprocally along its own axis, thereby driving the piston to slide reciprocally in the pump housing 630. In this way, the function of the piston pump is realized, enabling the fluid to enter through the second inlet and discharge from the second outlet. Additionally, it should be noted that when the piston slides, the first gear 612, the second gear 622, and the housing also slide synchronously.

[0080] Furthermore, the limiting mechanism 670 further includes a second drive assembly, and the second drive assembly is configured to limit the rotation of the first gear 612 under the starting condition. With such a design, it is ensured that when the insertion rod 642 rotates, it will not drive the first rotating shaft 611 to rotate, enabling effective sliding between the insertion rod 642 and the cam groove 6111.

[0081] In this embodiment, the side pump 600 further includes a flowmeter and a control unit; the flowmeter is used to measure the flow rate at the first inlet or the first outlet; the control unit is electrically connected to the flowmeter and the rotary motor 640 respectively.

[0082] Specifically, referring to Figure 2 、 Figure 3 and Figure 5 , a liquid inlet pipe 680 and a liquid outlet pipe 690 are fixed on the pump housing 630. The liquid inlet pipe 680 has one liquid inlet and three liquid outlets, and the liquid outlet pipe 690 has three liquid inlets and one liquid outlet. Among them, the three liquid outlets of the liquid inlet pipe 680 are correspondingly connected and arranged with the first inlet and the second inlet, and the three liquid inlets of the liquid outlet pipe 690 are correspondingly connected and arranged with the first outlet and the second outlet;

[0083] Continuing from the above, the first drive assembly includes a first cylinder 673 and a connecting frame, and the second drive assembly includes a second cylinder 674 and a clamping block 675; the control unit includes a controller and an electric telescopic rod 677.

[0084] Continuing with the above, the conical cover 672 is connected to the connecting frame. The first cylinder 673 is installed on the pump housing 630. 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 casing. The clamping block 675 is connected to the output end of the second cylinder 674. The second cylinder 674 extends to drive the clamping block 675 to be clamped to the first gear 612. The electric telescopic rod 677 is located inside the cylinder body 676. The piston plate at its output end divides the inner cavity of the cylinder body 676 into an upper cavity and a lower cavity. The cylinder body 676 is fixed to the pump housing 630. The upper cavity is communicated with the first cylinder 673, and the lower cavity is communicated with the second cylinder 674.

[0085] When the side line pump 600 is to work in the state of a twin-screw pump, referring to Figure 3 and Figure 5 as shown, the electric telescopic rod 677 drives the piston plate to move upward to compress the upper cavity, supplying pressure to the first cylinder 673. At this time, the output end of the first cylinder 673 extends to drive the connecting frame and the conical cover 672 to move in the direction close to the casing, so that the conical cover 672 squeezes the locking rod 671, causing the locking rod 671 to abut against the camshaft. At this time, the rotating 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, correspondingly, the second cylinder 674 retracts, causing the clamping block 675 to move away from the first gear 612, thus ensuring the normal rotation of the first gear 612, the first rotating shaft 611, the driving screw 610, etc.

[0086] When it is necessary to switch to the piston pump state for operation, the electric telescopic rod 677 drives the piston plate to move downward, compressing the lower cavity, supplying 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. In this way, the conical cover 672 moves in the direction away from the casing, causing the locking rod 671 to disengage from the first rotating shaft 611. At the same time, the clamping block 675 is clamped to the first gear 612, ensuring that the first gear 612 cannot rotate. At this time, the rotating motor 640 can drive the first rotating shaft 611 to reciprocate along its own axis, and further cause the piston to slide reciprocally in the pump housing 630.

[0087] When the side line pump 600 works in the state of a twin-screw pump, the controller obtains the rotation speed of the rotating motor 640 and the value of the flowmeter to judge whether the driving screw 610 and the driven screw 620 are corroded. If the flow rate is low at a specific rotation speed of the rotating motor 640, it indicates that the driving screw 610 and the 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, so that the side line pump 600 is switched to the piston pump state to ensure the normal operation of the side line pump 600.

[0088] An embodiment of the present invention also provides a process for the hydration of cyclohexene to cyclohexanol. The process for the hydration of cyclohexene to cyclohexanol is based on a cyclohexene hydration to cyclohexanol system and sequentially includes the following steps:

[0089] S1, The cyclohexene produced by the upstream unit is sent to the first alcohol tower 100 after being washed with water; S2, The cyclohexene in the upper-middle part of the first alcohol tower 100 is transported to the microinterface mixing device 200 through the side pipeline 500, and the catalyst at the bottom of the first hydration reactor 300 is transported to the microinterface mixing device 200 through the second pipeline 900; S3, The cyclohexene and the catalyst are mixed by the microinterface 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 and the remaining cyclohexene generated after the reaction are sent into the second hydration reactor 400 through the overflow pipeline 800 for hydration reaction again; S5, The mixed product in the second hydration reactor 400 is sent to the bottom of the first alcohol tower 100 through the third pipeline 1100, and then the mixed product is taken out from the bottom of the first alcohol tower 100 and purified, and then the unreacted cyclohexene is sent into the upper-middle part of the first alcohol tower 100 again.

[0090] In the above, a small amount of light components in cyclohexene (purity about 95%) are taken out from the top of the first alcohol tower 100 and returned to the upstream unit, while the cyclohexene with higher purity (purity about 97%) in the upper-middle part of the first alcohol tower 100 is transported to the microinterface mixing device 200 through the side line pump 600, and is fully mixed with the catalyst (aluminosilicate) taken out from the bottom of the first hydration reactor 300, and then sent into the first hydration reactor 300 together; Part of the cyclohexene reacts with water in the first hydration reactor 300 to generate cyclohexanol, and then the cyclohexanol and the remaining cyclohexene are sent to the second hydration reactor 400 through the overflow pipeline 800 for continuous reaction; The finally generated cyclohexanol is taken out from the bottom of the first alcohol tower 100 and sent to the distillation system for further purification, and the unreacted cyclohexene is returned to the first alcohol tower 100 and sent to the hydration reactor for continuous reaction.

[0091] The following takes a specific embodiment to illustrate the process for the hydration of cyclohexene to cyclohexanol provided by the present invention:

[0092] After the major overhaul of the hydration reactor in the cyclohexanone workshop, it was officially put into operation at 7:00 on July 26, 2024. Two sets of hydration reactions, namely set A and set B, were set up. Among them, set A was the experimental group, adopting the process for the hydration of cyclohexene to cyclohexanol provided by the present invention, and set B was the control group, adopting the existing process. The operating loads of the two were the same. The operating data after startup from July 27, 2024 to August 14, 2024 were collected, as Figure 6 shown.

[0093] It can be seen from the operating data after the overhaul that the operating data of set A hydration reaction are overall better than those of set B hydration reaction. That is to say, by pre-mixing the hydration catalyst slurry and cyclohexene outside the reactor, the reaction conversion rate can be improved.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements 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 cyclohexene hydration system for preparing cyclohexanol, characterized in that: include: An alcohol column (100), a microinterface mixing device (200), a first hydration reactor (300) and a second hydration reactor (400); The middle and upper part of the alcohol tower (100) is connected to the micro-interface mixing device (200) through a side pipeline (500), and a side line 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); The second pipeline (900) is provided with a slurry pump (1000).

2. The cyclohexene hydration system for preparing cyclohexanol 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 system for preparing cyclohexanol according to claim 1, characterized in that: The sideline pump (600) includes a driving screw (610), a driven screw (620), a pump housing (630) and a rotating motor (640); The active screw (610) is transmission-connected to the driven screw (620), and the two are meshed with each other. Both are arranged in 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 active screw (610) and the driven screw (620), and are both directly opposite to the meshing position of the active screw (610) and the driven screw (620); The rotating motor (640) is drivingly connected to the active screw (610).

4. The cyclohexene hydration system for preparing cyclohexanol according to claim 3, characterized in that: The side line pump (600) further comprises a first slide plate (650), a second slide 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 in the pump housing (630), and the side surfaces of the two slide plates are in contact with the inner wall of the pump housing (630); The pump housing (630) is also provided with two second inlets and two second outlets, and water inlet valves are respectively provided at the two second inlets, and water outlet valves are respectively provided at the two second outlets; The two second inlets are distributed outside the first slide plate (650) and the second slide plate (660), and the two second outlets are also distributed outside the first slide plate (650) and the second slide plate (660); One end of each of the active screw rod (610) and the driven screw rod (620) is rotatably connected to the first slide plate (650), and the other end of each of the active screw rod (610) and the driven screw rod (620) is rotatably connected to the second slide plate (660); A first rotating shaft (611) protrudes from one end of the active screw rod (610), 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 rotating motor (640).

5. The cyclohexene hydration system for preparing cyclohexanol according to claim 4, characterized in that: The motor shaft (641) 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) comprises a locking rod (671), a conical cover (672) and a first driving assembly; The locking rod (671) is inserted into the side wall of the motor shaft (641) along the radial direction of the motor shaft (641), and one end of the locking rod (671) is located outside the motor shaft (641) and is embedded with a ball, and the other end is used to contact the side wall of the first rotating shaft (611); A plurality of locking rods (671) are provided, and the plurality of 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 matched with the locking rod (671); The first driving assembly is drivingly 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 system for preparing cyclohexanol by hydration of cyclohexene according to claim 5, characterized in that: A cam groove (6111) is provided on the side wall of the first rotating shaft (611); An insertion rod (642) is fixed on the motor shaft (641), and the insertion rod (642) extends radially along the first rotating shaft (611), and a free end of the insertion rod (642) is inserted into the cam groove (6111).

7. The system for preparing cyclohexanol by hydration of cyclohexene according to claim 6, characterized in that: A first gear (612) is coaxially fixed on the first rotating shaft (611); A second rotating shaft (621) protrudes from one end of the driven screw rod (620), a second gear (622) is coaxially fixed on the second rotating shaft (621), and the second gear (622) is meshed with the first gear (612); The limiting mechanism (670) further includes a second driving assembly, wherein the second driving assembly is configured to limit the rotation of the first gear (612) under a starting condition.

8. The system for preparing cyclohexanol by hydration of cyclohexene according to claim 7, characterized in that: The sideline pump (600) further comprises a flow meter and a control unit; The flow meter is used to measure the flow at the first inlet or the first outlet; The control unit is electrically connected to the flow meter and the rotating motor (640) respectively.

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

10. The process for preparing cyclohexanol by hydration of cyclohexene according to claim 9, characterized in that: The following steps are also included: S5, sending the mixed product in the second hydration reactor (400) to the bottom of the alcohol tower (100) via the third pipeline (1100), then extracting and purifying the mixed product from the bottom of the alcohol tower (100), and then sending the unreacted cyclohexene to the middle and upper part of the alcohol tower (100) again.

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