Diluted cyclohexanone processing system

Abstract

The utility model relates to the technical field of chemical equipment, and particularly discloses a dilute cyclohexanone processing system, which is used for solving the problem of low use efficiency of a catalyst in the prior art. Comprising a first reactor and a second reactor, a first feed port of the first reactor is communicated with a benzene conveying pipeline, and a second feed port of the first reactor is communicated with a first branch pipe of a hydrogen conveying pipeline; and the feeding end of the second reactor is communicated with the second branch pipe of the hydrogen conveying pipeline. According to the utility model, the remote transmission interface level meter, the interface level control regulating valve and the corresponding process flow are additionally arranged in the flash tank in the existing production process steps, so that the settled catalyst and water in the flash tank are timely recycled to a catalyst regeneration system, and the possibility that the settled catalyst at the bottom of the flash tank is brought to a subsequent downstream device by materials is reduced; the loss of the hydrogenation catalyst is reduced, and the unit consumption of the catalyst in the cyclohexanone production process is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a dilute cyclohexanone processing system. Background Technology

[0002] In recent years, the domestic cyclohexanone production process has developed rapidly, especially the cyclohexene hydration process. With its advantages of being green and energy-saving, having fewer process side reactions, and producing products with lower impurity content, it is quickly becoming the mainstream production process in the industry. In the cyclohexanone production process using the cyclohexene method, the most critical step is the partial hydrogenation of benzene to produce cyclohexene. In this reaction, benzene and hydrogen are used as raw materials, and the partial hydrogenation of benzene is catalyzed by a ruthenium-zinc catalyst. However, in actual production, due to factors such as equipment maintenance, pipeline leaks, and inaccurate settling tank interface positioning, the catalyst is frequently lost. To maintain stable system operation, new catalyst must be continuously replenished, which undoubtedly increases production costs, and the problem of ruthenium-zinc catalyst loss is becoming increasingly prominent. Especially during the start-up and shutdown of the plant, catalyst loss caused by inaccurate settling tank interface positioning is one of the most difficult problems to control.

[0003] With the widespread application and capacity expansion of the cyclohexanone production process via the olefin method, the demand for ruthenium-zinc catalysts will continue to grow, undoubtedly exacerbating the pressure on catalyst supply. Therefore, reducing ruthenium-zinc catalyst loss, improving catalyst efficiency, and finding more stable and economical catalyst alternatives have become significant challenges facing the current cyclohexanone production process.

[0004] Based on this, a dilute cyclohexanone processing system is now provided, which can eliminate the drawbacks of existing systems. Utility Model Content

[0005] The purpose of this invention is to provide a dilute cyclohexanone processing system that solves the problem of low catalyst efficiency in the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A dilute cyclohexanone processing system includes a first reactor and a second reactor. The first reactor has a first inlet connected to a benzene delivery pipeline, and a second inlet connected to a first branch pipe of a hydrogen delivery pipeline. The second reactor has an inlet connected to a second branch pipe of the hydrogen delivery pipeline. The first reactor is equipped with a first reactor stirring system, and the second reactor is equipped with a second reactor stirring system. The discharge end of the first reactor is connected to the inlet of the second reactor via a first reactor outlet pipe. The discharge end of the second reactor is connected to the inlet of a settling tank via a second reactor outlet pipe. The discharge end of the settling tank is connected to a flash tank via a settling tank outlet pipe. The bottom of the flash tank has a bottom recovery pipe connected to the end of an auxiliary regeneration system pipe. The end of the auxiliary regeneration system pipe is connected to a catalyst regeneration system pipe of a hydrogenation catalyst regeneration system. The discharge end of the hydrogenation catalyst regeneration system has a pipe connecting the catalyst regeneration system to the main outlet pipe of the catalyst circulation pump. The upper end of the main outlet pipe of the catalyst regeneration system to the main outlet pipe of the catalyst circulation pump is connected to the return end of the first reactor via the main outlet pipe of the catalyst circulation pump.

[0008] Based on the above technical solutions, this utility model also provides the following optional technical solutions:

[0009] In one alternative: the flash tank is provided with a flash tank gas phase discharge pipe at the top discharge end.

[0010] In one alternative: the bottom of the settling tank is provided with a bottom discharge pipe, the lower end of which is connected to a catalyst circulation pump, and the discharge end of the catalyst circulation pump is connected to a catalyst regeneration system pipe of the hydrogenation catalytic regeneration system.

[0011] In one alternative: the outside of the settling tank is also equipped with a settling tank level gauge and a settling tank interface gauge for detection.

[0012] In one alternative: the flash tank is provided with a flash tank liquid phase discharge pipe for draining liquid on the outside; the flash tank is also provided with a flash tank level gauge and a flash tank on-site boundary gauge for detection on the outside; a test pipe connected to the auxiliary regeneration system pipeline is provided on the outside of the flash tank; a flash tank remote boundary gauge is provided on the test pipe; and a flash tank bottom sewage discharge pipe is also connected to the outside of the flash tank bottom recovery pipeline.

[0013] In one alternative: a flash tank interface control valve is installed on the recovery pipe at the bottom of the flash tank, and the test tube is connected to the third port of the flash tank interface control valve.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention adds a remote boundary level gauge, boundary level control valve, and corresponding process flow to the flash tank in the existing production process steps. This allows the settled catalyst and water in the flash tank to be recovered in a timely manner to the catalyst regeneration system, reducing the possibility that the catalyst settled at the bottom of the flash tank may be carried to subsequent downstream units by the material, reducing the loss of hydrogenation catalyst, and effectively reducing the catalyst consumption per unit in the cyclohexanone production process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure label annotations: 1 Hydrogen conveying pipeline, 2 Benzene conveying pipeline, 3 First reactor, 4 First reactor discharge pipeline, 5 First reactor stirring system, 6 Second reactor stirring system, 7 Second reactor, 8 Second reactor discharge pipeline, 9 Settling tank, 10 Settling tank bottom discharge pipeline, 11 Catalyst circulation pump, 12 Catalyst circulation pump outlet main pipeline, 13 Catalyst regeneration system pipeline, 14 Pipeline from catalyst regeneration system to catalyst circulation pump outlet main pipeline, 15 Settling tank discharge pipeline, 16 Flash tank, 17 Flash tank liquid phase discharge pipe, 18 Flash tank gas phase discharge pipe, 19 Flash tank level gauge, 20 Flash tank on-site boundary gauge, 21 Flash tank bottom drain pipeline, 22 Settling tank level gauge, 23 Settling tank boundary gauge, 24 Flash tank remote boundary gauge, 25 Flash tank bottom recovery pipeline, 26 Flash tank boundary control valve, 27 Auxiliary regeneration system pipeline. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] like Figure 1 As shown in the figure, this utility model embodiment provides a dilute cyclohexanone processing system, including a first reactor 3 and a second reactor 7. The first inlet of the first reactor 3 is connected to a benzene conveying pipeline 2, and the second inlet of the first reactor 3 is connected to a first branch pipe of a hydrogen conveying pipeline 1. The inlet of the second reactor 7 is connected to a second branch pipe of the hydrogen conveying pipeline 1. The first reactor 3 is provided with a first reactor stirring system 5 for stirring, and the second reactor 7 is provided with a second reactor stirring system 6 for stirring. The discharge end of the first reactor 3 is connected to the inlet of the second reactor 7 through a first reactor discharge pipe 4.

[0020] The discharge end of the second reactor 7 is connected to the inlet end of the settling tank 9 through the second reactor discharge pipe 8. The discharge end of the settling tank 9 is connected to the flash tank 16 through the settling tank discharge pipe 15. The top discharge end of the flash tank 16 is provided with a flash tank gas phase discharge pipe 18. The bottom of the flash tank 16 is provided with a flash tank bottom recovery pipe 25. The flash tank bottom recovery pipe 25 is connected to the end of the auxiliary regeneration system pipe 27. The end of the auxiliary regeneration system pipe 27 is connected to the catalyst regeneration system pipe 13 of the hydrogenation catalyst regeneration system. The discharge end of the hydrogenation catalyst regeneration system is provided with a pipe 14 from the catalyst regeneration system to the catalyst circulation pump outlet main pipe. The upper end of the pipe 14 from the catalyst regeneration system to the catalyst circulation pump outlet main pipe is connected to the return end of the first reactor 3 through the catalyst circulation pump outlet main pipe 12.

[0021] The bottom of the settling tank 9 is provided with a settling tank bottom discharge pipe 10. The lower end of the settling tank bottom discharge pipe 10 is connected to the catalyst circulation pump 11. The discharge end of the catalyst circulation pump 11 is connected to the catalyst regeneration system pipe 13 of the hydrogenation catalytic regeneration system. The outside of the settling tank 9 is also provided with a settling tank level gauge 22 and a settling tank interface gauge 23 for detection.

[0022] The flash tank 16 is provided with a flash tank liquid phase discharge pipe 17 for draining liquid on its outer side. The flash tank 16 is also provided with a flash tank level gauge 19 and a flash tank on-site boundary gauge 20 for detection on its outer side. The flash tank 16 is provided with a test pipe connected to the auxiliary regeneration system pipeline 27 on its outer side. The test pipe is provided with a flash tank remote boundary gauge 24. The flash tank bottom recovery pipeline 25 is also connected to a flash tank bottom sewage discharge pipeline 21 on its outer side. The flash tank bottom recovery pipeline 25 is provided with a flash tank boundary control valve 26. The test pipe is connected to the third port of the flash tank boundary control valve 26.

[0023] Working Principle: This invention adds a remote boundary level gauge, a boundary level control valve, and a drain pipe to the catalyst regeneration system before the lower part of the flash tank. With this added process, the material from the settling tank enters the flash tank after a certain residence time. Since the catalyst has a higher specific gravity than oil, the water containing the catalyst will settle at the bottom of the flash tank. During start-up, shutdown, and daily operation, the boundary level of the flash tank is controlled at specific parameters. When the boundary level rises, the boundary level control valve opens, draining the deposited catalyst and water into the catalyst regeneration system for recovery.

[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dilute cyclohexanone processing system, comprising a first reactor (3) and a second reactor (7), wherein the first inlet of the first reactor (3) is connected to a benzene conveying pipeline (2), and the second inlet of the first reactor (3) is connected to a first branch pipe of a hydrogen conveying pipeline (1); the inlet of the second reactor (7) is connected to a second branch pipe of the hydrogen conveying pipeline (1); Its features are: The first reactor (3) is equipped with a first reactor stirring system (5) for stirring, and the second reactor (7) is equipped with a second reactor stirring system (6) for stirring. The discharge end of the first reactor (3) is connected to the inlet end of the second reactor (7) through the first reactor outlet pipe (4); the discharge end of the second reactor (7) is connected to the inlet end of the settling tank (9) through the second reactor outlet pipe (8), and the discharge end of the settling tank (9) is connected to the flash tank (16) through the settling tank outlet pipe (15). The bottom of the flash tank (16) is equipped with a flash evaporator. The bottom recovery pipe (25) of the flash tank (16) is connected to the end of the auxiliary regeneration system pipe (27). The end of the auxiliary regeneration system pipe (27) is connected to the catalyst regeneration system pipe (13) of the hydrogenation catalyst regeneration system. The discharge end of the hydrogenation catalyst regeneration system is provided with a pipe (14) from the catalyst regeneration system to the catalyst circulation pump outlet main pipe. The upper end of the pipe (14) from the catalyst regeneration system to the catalyst circulation pump outlet main pipe is connected to the return end of the first reactor (3) through the catalyst circulation pump outlet main pipe (12).

2. The dilute cyclohexanone processing system according to claim 1, characterized in that, The flash tank (16) is provided with a flash tank gas phase discharge pipe (18) at the top discharge end.

3. The dilute cyclohexanone processing system according to claim 1, characterized in that, The bottom of the settling tank (9) is provided with a bottom discharge pipe (10), the lower end of which is connected to the catalyst circulation pump (11), and the discharge end of the catalyst circulation pump (11) is connected to the catalyst regeneration system pipe (13) of the hydrogenation catalytic regeneration system.

4. The dilute cyclohexanone processing system according to claim 3, characterized in that, The settling tank (9) is also equipped with a settling tank level gauge (22) and a settling tank boundary gauge (23) for detection.

5. The dilute cyclohexanone processing system according to claim 1, characterized in that, The flash tank (16) is provided with a flash tank liquid phase discharge pipe (17) for draining liquid on the outside. The flash tank (16) is also provided with a flash tank level gauge (19) and a flash tank field boundary gauge (20) for detection on the outside. The flash tank (16) is provided with a test pipe connected to the auxiliary regeneration system pipeline (27) on the outside. The test pipe is provided with a flash tank remote boundary gauge (24). The flash tank (16) bottom recovery pipeline (25) is also connected to the flash tank bottom sewage pipe (21) on the outside.

6. The dilute cyclohexanone processing system according to claim 5, characterized in that, A flash tank interface control valve (26) is installed on the recovery pipe (25) at the bottom of the flash tank, and the test tube is connected to the third port of the flash tank interface control valve (26).

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