Efficient energy-saving refining system for producing cyclohexanone through dehydrogenation

Abstract

The invention belongs to the technical field of chemical production, and particularly relates to an efficient energy-saving refining system for producing cyclohexanone through dehydrogenation, which comprises an alcohol tower, a dehydrogenation heat exchanger, a dehydrogenation reactor, an alcohol tower feeding heat exchanger, a dehydrating tower, a light tower I, a light tower II, a ketone tower and an alcohol recovery tower which are connected in sequence, a middle feeding port of the alcohol tower is communicated with a tube pass discharging port of the alcohol tower feeding heat exchanger, a top discharging port of the alcohol tower is communicated with a tube pass feeding port of the dehydrogenation heat exchanger, a bottom discharging port of the alcohol tower is communicated with a middle feeding port of the alcohol recovery tower, and an alcohol ketone drying tower is additionally arranged between the alcohol tower feeding heat exchanger and the dehydration tower. A feed port of the alcohol ketone drying tower is communicated with a shell pass discharge port of the alcohol tower feed heat exchanger, and a liquid phase discharge port of the alcohol ketone drying tower is communicated with an upper feed port of the dehydrating tower. The alcohol tower adopts a process that raw materials directly enter the tower top, tower top reflux is cancelled, steam consumption is reduced, and the purpose of saving energy is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and particularly relates to a high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation. Background Art

[0002] Cyclohexanone is a key chemical product, boasting excellent properties such as high solubility and low volatility. It is used as a solvent for nitrocellulose cellulose ether, vinyl chloride polymers, and copolymers in paints. Cyclohexanone is also an intermediate in the production of amides such as caprolactam, adipic acid, and nylon 66. Cyclohexanone is also used in inks, pesticides, antioxidants, and adhesives.

[0003] Currently, the main cyclohexanone production processes include phenol hydrogenation, cyclohexane oxidation, and cyclohexene hydration. Cyclohexene hydration has been the primary process for projects under construction in recent years. The cyclohexene hydration process involves benzene hydrogenation, cyclohexene hydration, cyclohexanol dehydrogenation, and cyclohexanone refining. Because the conversion rate of cyclohexanol dehydrogenation to cyclohexanone is 45% to 50%, the dehydrogenation product, the alcohol ketone, is refined in a ketone column to produce the cyclohexanone product. The cyclohexanol is separated and condensed overhead in the alcohol column and then returned to the dehydrogenation reactor for dehydrogenation. This process consumes a lot of steam, making it a major energy-intensive step.

[0004] Patent publication number CN113461500B discloses a cyclohexanol dehydrogenation purification system for cyclohexanone. The system comprises an alcohol column (I), a dehydrogenation reactor, a dehydrogenation heat exchanger, an alcohol column feed heat exchanger, a light column (I), a coupled reboiler, a light column (II), a ketone column, and an alcohol column (II). This system redesigns the six-column process flow to achieve refined separation of the cyclohexanol dehydrogenation product. By coupling available heat and cooling resources, the system improves product yield, saves steam, reduces operating costs, and reduces the discharge of three wastes.

[0005] However, the technical solution in the aforementioned patent requires the installation of an alcohol condenser, which increases steam energy consumption during the cyclohexanol separation process. The dehydration column feed consists of a liquid phase of the condensed dehydrogenation reaction product, requiring further steam to vaporize the material. This increases the energy consumption of the cyclohexanone refining unit and increases production costs. Furthermore, because the alcohol secondary column utilizes a stripping tower, the overhead gas phase is susceptible to containing heavy components, resulting in substandard cyclohexanol purity at the top of the ketone column and reduced product quality. Summary of the Invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation. The alcohol tower adopts a process in which the raw materials directly enter the tower top, eliminating the tower top reflux and reducing steam consumption. The alcohol-ketone drying tower utilizes the heat of the reaction products and adopts gas-liquid two-phase feed, thereby improving the purity of hydrogen while further reducing steam consumption and achieving the purpose of energy saving.

[0007] The specific technical solution adopted in the present invention is:

[0008] A high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation comprises an alcohol tower, a dehydrogenation heat exchanger, a dehydrogenation reactor, an alcohol tower feed heat exchanger, a dehydration tower, a light tower 1, a light tower 2, a ketone tower and an alcohol recovery tower which are connected in sequence. A ketone tower coupling reboiler is provided between the light tower 1 and the ketone tower. The middle feed port of the alcohol tower is communicated with the tube-side discharge port of the alcohol tower feed heat exchanger, the top discharge port of the alcohol tower is communicated with the tube-side feed port of the dehydrogenation heat exchanger, the bottom discharge port of the alcohol tower is communicated with the middle feed port of the alcohol recovery tower, an alcohol-ketone drying tower is additionally provided between the alcohol tower feed heat exchanger and the dehydration tower, the feed port of the alcohol-ketone drying tower is communicated with the shell-side discharge port of the alcohol tower feed heat exchanger, and the liquid phase discharge port of the alcohol-ketone drying tower is communicated with the upper feed port of the dehydration tower.

[0009] The top of the alcohol-ketone drying tower is provided with an alcohol-ketone drying tower condenser and an alcohol-ketone drying tower reflux tank. The feed port of the alcohol-ketone drying tower condenser is connected to the gas phase discharge port of the alcohol-ketone drying tower, and the liquid phase discharge port of the alcohol-ketone drying tower condenser is connected to the feed port of the alcohol-ketone drying tower reflux tank.

[0010] An alcohol-ketone drying tower reboiler is provided at the bottom of the alcohol-ketone drying tower, the feed port of the alcohol-ketone drying tower reboiler is connected to the reboiler discharge port of the alcohol-ketone drying tower, and the discharge port of the alcohol-ketone drying tower reboiler is connected to the reboiler feed port of the alcohol-ketone drying tower.

[0011] The alcohol-ketone drying tower includes a tower body, in which a plurality of groups of tower plates are arranged at intervals in the vertical direction in the chamber of the tower body, one side of the tower plate is fixedly connected to the interior of the tower body, and an overflow weir is provided on the other side of the tower plate. Adjacent tower plates are arranged in opposite directions, and the chamber of the tower body is formed into an S-shaped flow channel by means of the plurality of groups of tower plates.

[0012] The feed inlet of the alcohol-ketone drying tower is a mixed phase feed inlet, and a feed distributor is provided at the mixed phase feed inlet. The feed distributor is an inverted funnel-shaped structure, and the narrow mouth of the funnel-shaped structure is formed as the feed inlet of the feed distributor. The mixed phase feeding direction of the alcohol-ketone drying tower is tangent to the feed inlet of the feed distributor.

[0013] A spiral guide channel is provided inside the feed distributor. The guide channel is formed by means of arc-shaped guide blades. The angle between the working surface of the guide blade and the generatrix of the inner wall of the feed distributor is 30-60 degrees.

[0014] The guide blades are provided in multiple groups, and the guide channels are provided in multiple sections. The input end of the guide blades of the next stage is located 5-10 cm below the guide blades of the previous stage.

[0015] The feed distributor is also provided with a drainage tube, which is coaxially arranged with the center of the feed distributor. One end of the drainage tube is located above the feed distributor, and the other end of the drainage tube passes through the feed port of the feed distributor and extends to the bottom of the feed distributor. The tube wall of the drainage tube is also provided with air inlet holes, and the air inlet holes are arranged in multiple groups at intervals and in a spiral shape. The air inlet holes are arranged corresponding to the position of the guide plate.

[0016] The diameters of the air inlet holes increase gradually from bottom to top along the axial direction of the drainage tube, and the spacings between adjacent air inlet holes increase gradually from bottom to top along the axial direction of the drainage tube.

[0017] The feed port of the alcohol-ketone drying tower includes a gas phase feed port and a liquid phase feed port, and the gas phase feed port and the liquid phase feed port are respectively connected to the shell side discharge port of the alcohol tower feed heat exchanger

[0018] The beneficial effects of the present invention are:

[0019] 1. In the present invention, the alcohol tower adopts a process in which the raw materials directly enter the tower top, eliminating the tower top reflux and reducing steam consumption. The alcohol-ketone drying tower utilizes the heat of the reaction products and adopts gas-liquid two-phase feed, thereby improving the purity of hydrogen while further reducing steam consumption and achieving energy conservation. Compared with the existing technology, the heat load of a 300,000 tons / year cyclohexanone production unit is reduced by about 14,660 kW. Based on 2.5 MPaG high-pressure steam, steam consumption can be saved by about 28 t / h.

[0020] 2. The alcohol recovery tower of the present invention is fed with materials, and an alcohol recovery tower condenser and an alcohol recovery tower reflux tank are provided to control the content of heavy components in the top discharge port of the alcohol recovery tower, thereby ensuring the quality of the cyclohexanone product at the top discharge port of the ketone tower.

[0021] 3. The light tower and the ketone tower of the present invention are thermally coupled to reduce steam consumption and achieve energy saving.

[0022] 4. The gaseous material at the top of the alcohol tower of the present invention directly enters the dehydrogenation reactor after heat exchange in the dehydrogenation heat exchanger, thereby reducing the consumption of steam and circulating water and achieving energy saving.

[0023] 5. The alcohol recovery tower of the present invention further reduces the cyclohexanol content in the X oil in the bottom of the tower and improves the recovery rate of cyclohexanol; BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the system structure of specific embodiment 1;

[0025] Figure 2 Schematic diagram of the structure of the alcohol-ketone drying tower;

[0026] Figure 3 Schematic diagram of the top view of the feed distributor;

[0027] Figure 4 Schematic diagram of the cross-sectional structure of the feed distributor;

[0028] Figure 5 Schematic diagram of the system structure of specific embodiment 2;

[0029] In the attached drawings, 1. condenser of alcohol-ketone drying tower, 2. reflux tank of alcohol-ketone drying tower, 3. reboiler of alcohol-ketone drying tower, 4. tower body, 5. tower plate, 6. overflow weir, 7. feed distributor, 8. guide vane, 9. drainage pipe, 10. air inlet, 11. mixed phase feed pipe. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0031] Specific embodiment 1, as Figure 1 As shown, the present invention provides a high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation, comprising an alcohol tower, a dehydrogenation heat exchanger, a dehydrogenation reactor, an alcohol tower feed heat exchanger, a dehydration tower, a light tower 1, a light tower 2, a ketone tower and an alcohol recovery tower connected in sequence, a ketone tower coupling reboiler is provided between the light tower 1 and the ketone tower, the middle feed port of the alcohol tower is connected to the tube-side discharge port of the alcohol tower feed heat exchanger, the top discharge port of the alcohol tower is connected to the tube-side feed port of the dehydrogenation heat exchanger, the bottom discharge port of the alcohol tower is connected to the middle feed port of the alcohol recovery tower, an alcohol-ketone drying tower is additionally provided between the alcohol tower feed heat exchanger and the dehydration tower, the feed port of the alcohol-ketone drying tower is connected to the shell-side discharge port of the alcohol tower feed heat exchanger, and the liquid phase discharge port of the alcohol-ketone drying tower is connected to the upper feed port of the dehydration tower.

[0032] Existing dehydrogenation systems for cyclohexanone production require an alcohol condenser, increasing steam energy consumption during the cyclohexanol separation process. The dehydration column feed consists of the condensed liquid phase of the dehydrogenation reaction product, requiring further steam vaporization. This increases energy consumption in the cyclohexanone refining unit and increases production costs. Furthermore, because the alcohol secondary column utilizes a stripping tower, the overhead vapor phase is prone to containing heavy components, resulting in substandard cyclohexanol purity at the top of the ketone column and reduced product quality.

[0033] Therefore, the alcohol tower of the present invention adopts a process in which raw materials directly enter the tower top, eliminates the tower top reflux, reduces steam consumption, and achieves energy saving. At the same time, an alcohol-ketone drying tower is added. The alcohol-ketone drying tower utilizes the heat of the reaction products and adopts gas-liquid two-phase feeding, thereby improving the purity of hydrogen and reducing steam consumption, thereby achieving energy saving.

[0034] a dehydrogenation heat exchanger, wherein the tube-side feed port of the dehydrogenation heat exchanger is connected to the gas phase discharge port at the top of the alcohol tower, the tube-side discharge port of the dehydrogenation heat exchanger is connected to the feed port of the dehydrogenation reactor, the shell-side feed port of the dehydrogenation heat exchanger is connected to the discharge port of the dehydrogenation reactor, and the shell-side discharge port of the dehydrogenation heat exchanger is connected to the shell-side feed port of the alcohol tower feed heat exchanger;

[0035] An alcohol tower feed heat exchanger, wherein the shell-side feed port of the alcohol tower feed heat exchanger is connected to the shell-side discharge port of the dehydrogenation heat exchanger, and the tube-side discharge port of the alcohol tower feed heat exchanger is connected to the middle feed port of the alcohol tower;

[0036] An alcohol-ketone drying tower, wherein the middle feed port of the alcohol-ketone drying tower is connected to the shell-side gas and liquid phase discharge ports of the alcohol tower feed heat exchanger;

[0037] A dehydration tower, wherein the upper feed port of the dehydration tower is connected to the discharge port of the alcohol-ketone drying tower kettle;

[0038] A light tower, wherein the middle feed port of the light tower is connected to the discharge port of the dehydration tower kettle;

[0039] Light tower 2, wherein the middle feed port of the light tower 2 is connected to the discharge port of the reflux tank of light tower 1, and the bottom discharge port of the light tower 2 is connected to the middle feed port of light tower 1;

[0040] A ketone tower, wherein the middle feed port of the ketone tower is respectively connected to the bottom discharge port of the light tower and the tube-side discharge port of the coupled reboiler, and the bottom discharge port of the ketone tower is respectively connected to the tube-side feed port of the coupled reboiler and the tube-side feed port of the alcohol tower feed heat exchanger;

[0041] A ketone tower coupled reboiler, wherein the shell side feed port of the ketone tower coupled reboiler is connected to the discharge port at the top of the light tower, and the shell side discharge port of the coupled reboiler is connected to the reflux port at the top of the light tower;

[0042] The alcohol tower has a middle feed port connected to the tube side feed port of the alcohol tower feed heat exchanger, a top feed port connected to the tube side feed port of the dehydrogenation heat exchanger, and a bottom feed port connected to the middle feed port of the alcohol recovery tower.

[0043] An alcohol recovery tower, wherein a middle feed port of the alcohol recovery tower is connected to a bottom discharge port of the alcohol tower, and a top discharge port of the alcohol recovery tower is connected to a bottom feed port of the ketone tower.

[0044] The process of dehydrogenating cyclohexanol to refine cyclohexanone of the present invention is as follows:

[0045] Cyclohexanol is directly fed to the top of the alcohol column as the top reflux of the alcohol column. The gaseous cyclohexanol separated from the top of the alcohol column is directly fed into the dehydrogenation reactor for dehydrogenation reaction after heat exchange with the dehydrogenation reaction product in the dehydrogenation heat exchanger.

[0046] The reaction product from the dehydrogenation reactor exits the dehydrogenation heat exchanger and enters the alcohol column feed heat exchanger for further heat exchange. The condensed liquid phase and non-condensable gases after heat exchange enter the alcohol-ketone drying column. The lighter components in the reaction product are separated from the top of the alcohol-ketone drying column and enter the alcohol-ketone drying column condenser 1. The condensate returns to the alcohol-ketone drying column as reflux, and the hydrogen is discharged as non-condensable gas.

[0047] The crude ketone after dehydrogenation is sent from the kettle of the ketone drying tower to the dehydration tower, and after dehydration in the dehydration tower, it is sent from the kettle of the dehydration tower to the light tower.

[0048] The light components in the crude ketone alcohol are distilled from the top of the Light 1 column. A portion enters the ketone column's coupled reboiler to serve as a heat source for the ketone column kettle, while the remaining portion is condensed in the Light 1 column's condenser and then enters the Light 1 column's reflux tank. The uncondensed vapor phase from the ketone column's coupled reboiler enters the Light 1 column's condenser, and the condensate enters the Light 1 column's reflux tank. A portion of the material in the Light 1 column's reflux tank returns to the Light 1 column as reflux, while the remaining portion enters the Light 2 column.

[0049] The light component evaporates from the top of the light tower 2, and after condensation in the light tower 2 condenser, the condensate enters the light tower 2 reflux tank, and the non-condensable gas is discharged by the vacuum system. After the condensate is phase-separated in the light tower 2 reflux tank, the light oil is sent out of the boundary area;

[0050] The crude ketone alcohol, after light components have been removed, enters the ketone column from the kettle of the light column. Cyclohexanone evaporates from the top of the ketone column and, after condensation, flows into the ketone reflux tank. Non-condensable gases are discharged through the vacuum system. A portion of the condensate is sent to the top of the ketone column as reflux, and the remainder is sent to the cyclohexanone product delivery device. Cyclohexanol and heavy components are pumped from the ketone column kettle discharge pump to the alcohol column feed heat exchanger, where they are preheated and then enter the alcohol column.

[0051] Cyclohexanol is extracted from the top of the alcohol column, heated in a dehydrogenation heat exchanger, and then fed into the dehydrogenation reactor. Cyclohexanol and X-oil are then transported from the bottom of the alcohol column to the alcohol recovery column. The vapor from the top of the alcohol recovery column enters the bottom of the ketone column, while X-oil is extracted from the bottom of the column and sent to the boundary area.

[0052] like Figure 1-2 As shown, the top of the alcohol-ketone drying tower is provided with an alcohol-ketone drying tower condenser 1 and an alcohol-ketone drying tower reflux tank 2, the feed port of the alcohol-ketone drying tower condenser 1 is connected with the gas phase discharge port of the alcohol-ketone drying tower, and the liquid phase discharge port of the alcohol-ketone drying tower condenser 1 is connected with the feed port of the alcohol-ketone drying tower reflux tank 2.

[0053] like Figure 1-2 As shown, an alcohol ketone drying tower reboiler 3 is provided at the bottom of the alcohol ketone drying tower, the feed port of the alcohol ketone drying tower reboiler 3 is connected to the reboiled discharge port of the alcohol ketone drying tower, and the discharge port of the alcohol ketone drying tower reboiler 3 is connected to the reboiled feed port of the alcohol ketone drying tower.

[0054] like Figure 2As shown, the alcohol-ketone drying tower includes a tower body 4, and a plurality of groups of tower plates 5 are arranged in the chamber of the tower body 4 at intervals along the vertical direction. One side of the tower plate 5 is fixedly connected to the interior of the tower body 4, and an overflow weir 6 is provided on the other side of the tower plate 5. Adjacent tower plates 5 are arranged in opposite directions, and the chamber of the tower body 4 is formed into an S-shaped flow channel by means of the plurality of groups of tower plates 5.

[0055] The S-shaped flow channel can extend the gas-liquid flow path, thereby increasing the contact time between the gas and liquid phases of the feed, thereby improving the separation efficiency.

[0056] like Figure 2-4 As shown, the feed inlet of the alcohol-ketone drying tower is a mixed phase feed inlet, and a feed distributor 7 is provided at the mixed phase feed inlet. The feed distributor 7 is an inverted funnel-shaped structure, and the narrow mouth of the funnel-shaped structure is formed as the feed inlet of the feed distributor 7. The mixed phase feed direction of the alcohol-ketone drying tower is tangent to the feed inlet of the feed distributor 7.

[0057] The inverted funnel-type feed separator has a smaller diameter at the top than at the bottom, forming a frustum of cones. This design, in contrast to traditional feed separators, allows the cross-sectional area of the gas-liquid mixture to gradually expand as it enters the tower. This expanded space at the bottom causes the gas-liquid flow rate to drop sharply, providing ample space for centrifugal separation. Traditional feed methods result in high gas entrainment due to the impact of gas and liquid on tray 5. This structure combines diameter expansion and deceleration with cyclonic separation to enable the liquid phase to settle earlier within the funnel, thereby reducing gas entrainment.

[0058] like Figure 4 As shown, the guide blades 8 on the inner wall of the feed distributor 7 are spirally distributed at an inclination angle of 45°, guiding the gas-liquid mixture to perform rotational motion, generating centrifugal force. Under the action of the centrifugal force, the liquid phase performs rotational motion along the guide channel and flows toward the tower plate 5 in an inclined direction, reducing the impact force on the tower plate 5; while the gas phase forms a vortex in the center and rises upward, thereby achieving preliminary separation of gas and liquid and improving separation efficiency.

[0059] like Figure 4 As shown, the guide blades 8 are provided in multiple groups, and the guide channels are provided in multiple sections. The input end of the guide blades 8 of the next stage is located 5-10 cm below the guide blades 8 of the previous stage.

[0060] Since the liquid phase has a certain inertia during the centrifugal motion, it can cross the cliff to form continuous motion. At the same time, since the liquid phase falls in the process of crossing the cliff, it accelerates under the action of gravity, but the gas phase does not accelerate. Therefore, a secondary separation is formed at the cliff, which reduces the time for the gas phase to entrain the liquid phase and reduces the amount of gas entrainment, thereby improving the separation efficiency.

[0061] like Figure 3-4As shown, the feed distributor 7 is also provided with a drainage tube 9, which is coaxially arranged with the center of the feed distributor 7, one end of the drainage tube 9 is located above the feed distributor 7, and the other end of the drainage tube 9 passes through the feed port of the feed distributor 7 and extends to the bottom of the feed distributor 7. The tube wall of the drainage tube 9 is also provided with air inlet holes 10, and the air inlet holes 10 are arranged in multiple groups at intervals and arranged in a spiral shape, and the air inlet holes 10 are arranged corresponding to the position of the guide plate.

[0062] When the gas enters the drainage tube 9 through the inlet hole 10, the shrinking tube diameter creates a Venturi effect, significantly increasing the flow rate and strengthening the upward momentum, thereby improving separation efficiency. Furthermore, the inlet hole 10 is aligned with the guide vanes 8, allowing the swirling gas phase to precisely enter the drainage tube 9, reducing the entrainment of the liquid phase.

[0063] like Figure 4 As shown, the diameter of the air inlet holes 10 increases step by step from bottom to top along the axial direction of the drainage tube 9 , and the spacing between adjacent air inlet holes 10 increases step by step from bottom to top along the axial direction of the drainage tube 9 .

[0064] The gradual increase in the aperture and spacing makes the pressure drop gradient in the drainage tube 9 gentle, thus avoiding gas backflow caused by local high pressure.

[0065] Specific embodiment 2, as Figure 5 As shown, the feed inlet of the alcohol-ketone drying tower described in Specific Example 2 includes a gas-phase feed inlet and a liquid-phase feed inlet, and the gas-phase feed inlet and the liquid-phase feed inlet are respectively connected to the shell-side discharge port of the alcohol tower feed heat exchanger. Since the gas-phase feed inlet and the liquid-phase feed inlet of the alcohol-ketone drying tower are respectively provided, gas-liquid pre-separation has been formed, and therefore there is no need to provide a feed distributor 7.

Claims

1. A high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation, comprising an alcohol tower, a dehydrogenation heat exchanger, a dehydrogenation reactor, an alcohol tower feed heat exchanger, a dehydration tower, a first light tower, a second light tower, a ketone tower, and an alcohol recovery tower connected in sequence, wherein a ketone tower coupling reboiler is provided between the first light tower and the ketone tower, characterized in that: The middle feed port of the alcohol tower is connected to the tube-side discharge port of the alcohol tower feed heat exchanger, the top discharge port of the alcohol tower is connected to the tube-side feed port of the dehydrogenation heat exchanger, the bottom discharge port of the alcohol tower is connected to the middle feed port of the alcohol recovery tower, and an alcohol-ketone drying tower is additionally provided between the alcohol tower feed heat exchanger and the dehydration tower. The feed port of the alcohol-ketone drying tower is connected to the shell-side discharge port of the alcohol tower feed heat exchanger, and the liquid phase discharge port of the alcohol-ketone drying tower is connected to the upper feed port of the dehydration tower.

2. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 1, characterized in that: The top of the alcohol-ketone drying tower is provided with an alcohol-ketone drying tower condenser (1) and an alcohol-ketone drying tower reflux tank (2); the feed port of the alcohol-ketone drying tower condenser (1) is communicated with the gas phase discharge port of the alcohol-ketone drying tower, and the liquid phase discharge port of the alcohol-ketone drying tower condenser (1) is communicated with the feed port of the alcohol-ketone drying tower reflux tank (2).

3. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 1, characterized in that: An alcohol-ketone drying tower reboiler (3) is provided at the bottom of the alcohol-ketone drying tower, the feed port of the alcohol-ketone drying tower reboiler (3) is connected to the reboiler discharge port of the alcohol-ketone drying tower, and the discharge port of the alcohol-ketone drying tower reboiler (3) is connected to the reboiler feed port of the alcohol-ketone drying tower.

4. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 1, characterized in that: The alcohol-ketone drying tower comprises a tower body (4), wherein a plurality of groups of tower plates (5) are arranged in a vertically spaced relationship in a chamber of the tower body (4), one side of the tower plates (5) is fixedly connected to the interior of the tower body (4), and an overflow weir (6) is arranged on the other side of the tower plates (5). Adjacent tower plates (5) are arranged in opposite directions, and the chamber of the tower body (4) is formed into an S-shaped flow channel by means of the plurality of groups of tower plates (5).

5. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 4, characterized in that: The feed inlet of the alcohol-ketone drying tower is a mixed phase feed inlet, and a feed distributor (7) is provided at the mixed phase feed inlet. The feed distributor (7) is an inverted funnel-shaped structure, and the narrow mouth of the funnel-shaped structure forms the feed inlet of the feed distributor (7). The mixed phase feed direction of the alcohol-ketone drying tower is tangent to the feed inlet of the feed distributor (7).

6. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 5, characterized in that: The feed distributor (7) is provided with a spiral guide channel inside. The guide channel is formed by means of an arc-shaped guide vane (8). The working surface of the guide vane (8) and the generatrix of the inner wall of the feed distributor (7) are at an angle of 30-60 degrees.

7. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 6, characterized in that: The guide blades (8) are provided in multiple groups, and the guide channels are provided in multiple sections, and the input end of the next-stage guide blade (8) is located 5-10 cm below the previous-stage guide blade (8).

8. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 6, characterized in that: The feed distributor (7) is also provided with a drainage pipe (9), which is coaxially arranged with the center of the feed distributor (7), one end of the drainage pipe (9) is located above the feed distributor (7), and the other end of the drainage pipe (9) passes through the feed port of the feed distributor (7) and extends to the bottom of the feed distributor (7), and the tube wall of the drainage pipe (9) is also provided with air inlet holes (10), and the air inlet holes (10) are arranged in multiple groups at intervals and in a spiral shape, and the air inlet holes (10) are arranged corresponding to the position of the guide plate.

9. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 8, characterized in that: The diameter of the air inlet holes (10) increases step by step from bottom to top along the axial direction of the drainage tube (9), and the spacing between adjacent air inlet holes (10) increases step by step from bottom to top along the axial direction of the drainage tube (9).

10. The high-efficiency and energy-saving refining system for producing cyclohexanone by dehydrogenation according to claim 1, characterized in that: The feed inlet of the alcohol-ketone drying tower includes a gas-phase feed inlet and a liquid-phase feed inlet, and the gas-phase feed inlet and the liquid-phase feed inlet are respectively communicated with the shell-side discharge port of the alcohol tower feed heat exchanger.

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