Intermediate phase separation device for waste alkali and alkaline water in cyclohexane oxidation method

Abstract

The utility model provides a cyclohexane oxidation process waste alkali and alkaline water intermediate phase separation device which comprises a first waste alkali liquid separator, a second waste alkali liquid separator, a washing extraction tower, a third waste alkali liquid separator and a cyclone hydraulic separator which are sequentially connected through pipelines, the first waste alkali liquid separator is connected with decomposition liquid from a cyclohexane oxygenolysis system, the cyclone hydraulic separator is connected with a cyclohexane recovery system, and the top of the washing extraction tower is connected with a pure water pipeline. The decomposition liquid from a cyclohexane oxygenolysis system passes through the first waste alkali liquid separator and the second waste alkali liquid separator, so that more than 98% of inorganic phases in the decomposition liquid can be separated, conditions are created for subsequent alkaline water intermediate phase separation, long-period stable operation of a cyclohexane recovery system is ensured, the operation period of a cyclohexanone device is ensured, and the production cost is reduced. The sodium ion content of the organic phase of the cyclohexane recovery system is reduced, and meanwhile, the intermediate phase polymer is prevented from being brought to the cyclohexane recovery system.

Description

Technical Field

[0001] The utility model relates to the technical field of production of cyclohexane oxidation units, in particular to a device for separating waste alkali and alkaline water intermediate phases in a cyclohexane oxidation process. Background Art

[0002] Cyclohexane oxidation is a very important production unit in the cyclohexanone production plant. Due to its low conversion rate and high yield reaction characteristics in the cyclohexane oxidation unit, after the organic matter in the large circulation of the system enters the heterogeneous decomposition reaction, it needs to be separated into the inorganic phase and the intermediate phase through the waste alkali liquid before entering the cyclohexane recovery system for distillation. The recovered cyclohexane is circulated to the cyclohexane oxidation process. After concentration, the cyclohexane, cyclohexanone and cyclohexanol mixture enters the next process.

[0003] In the traditional separation of waste alkali liquid, sedimentation separation or sedimentation + cyclone separation technology is more often used to reduce the sodium ion content in the organic phase of the cyclohexane recovery system by increasing the volume and extending the residence time. In recent years, through detection and analysis, the intermediate phase polymer in the organic phase of the cyclohexane recovery system has gradually become the main factor affecting its heat exchange efficiency. The use of a single sedimentation separation makes the separation effect insufficient. The organic phase of the cyclohexane recovery system contains trace amounts of sodium ions and intermediate phase polymers, which reduces the heat exchange efficiency of the cyclohexane recovery system and further affects the operation cycle of cyclohexanone production. In order to ensure the long-term stable operation of the cyclohexane recovery system and ensure the operation cycle of the cyclohexanone unit, it is necessary to adopt a new and practical process route to reduce the sodium ion content of the organic phase of the cyclohexane recovery system and avoid the intermediate phase polymer from being brought into the cyclohexane recovery system. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a cyclohexane oxidation process waste alkali alkali water intermediate phase separation device. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A cyclohexane oxidation process waste alkali-water intermediate phase separation device comprises a first waste alkali liquid separator, a second waste alkali liquid separator, a water washing extraction tower, a third waste alkali liquid separator and a hydrocyclone separator which are sequentially connected through pipelines, wherein the first waste alkali liquid separator is connected to the decomposition liquid from the cyclohexane oxidation decomposition system, the hydrocyclone separator is connected to the cyclohexane recovery system, and the top of the water washing extraction tower is connected to the pure water pipeline.

[0006] Furthermore, the bottom discharges of the first waste alkali liquid separator and the second waste alkali liquid separator are respectively connected to the cyclohexane oxidation decomposition system, the bottom discharges of the water washing extraction tower and the third waste alkali liquid separator are connected to the cyclohexane oxidation decomposition system after being merged, and the bottom discharge of the cyclone separator is connected to the cyclohexane oxidation decomposition system after being merged with the bottom discharges of the water washing extraction tower and the third waste alkali liquid separator.

[0007] Furthermore, the front ends of the first waste alkali liquid separator and the water washing extraction tower are provided with flow detectors and control regulating valves, and the first waste alkali liquid separator, the second waste alkali liquid separator, the water washing extraction tower, the third waste alkali liquid separator and the cyclone separator are all installed with interface detectors.

[0008] Furthermore, the flow detector and the control regulating valve are both connected to a centralized control system for automated control.

[0009] Compared with the prior art, the utility model has the following beneficial effects:

[0010] 1. The decomposition liquid from the cyclohexane oxidation decomposition system is firstly passed through the first waste alkali liquid separator and the second waste alkali liquid separator to separate more than 98% of the inorganic phase in the decomposition liquid, thus creating conditions for the subsequent alkali-water intermediate phase separation.

[0011] 2. The organic phase discharged from the second waste alkali liquid separator is sent to the water washing extraction tower. After sufficient contact with the continuous water phase and top pure water distribution water washing, the sodium ions and intermediate phase polymers in the organic phase can be washed out and gathered at the interface and inorganic phase.

[0012] 3. The organic phase discharged from the top of the water-wash extraction tower is separated by the third waste alkali liquid separator and the hydrocyclone separator, so as to separate the saturated inorganic phase carried by the organic phase discharged from the top of the water-wash extraction tower, thereby creating conditions for the organic phase with less impurities to enter the cyclohexane recovery system, thereby ensuring the heat exchange cycle of the cyclohexane recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0014] Figure 1 It is a schematic diagram of the structural flow of an embodiment of the utility model.

[0015] In the above drawings: cyclohexane oxidation decomposition system 1, the first waste alkali liquid separator 2, the second waste alkali liquid separator 3, the water washing extraction tower 4, the third waste alkali liquid separator 5, the cyclone separator 6, the cyclohexane recovery system 7, the pure water pipeline 8, the flow detector 9, the control regulating valve 10, and the interface detector 11. DETAILED DESCRIPTION

[0016] The technical solution of the present utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0017] Example 1

[0018] Please refer to Figure 1As shown, a cyclohexane oxidation process waste alkali alkali water intermediate phase separation device includes a first waste alkali liquid separator 2, a second waste alkali liquid separator 3, a water washing extraction tower 4, a third waste alkali liquid separator 5 and a hydrocyclone 6 which are connected in sequence through pipelines, the first waste alkali liquid separator 2 is connected to the decomposition liquid from the cyclohexane oxidation decomposition system 1, the hydrocyclone 6 is connected to the cyclohexane recovery system 7, and the top of the water washing extraction tower 4 is connected to the pure water pipeline 8.

[0019] After the decomposition liquid from the cyclohexane oxidation decomposition system 1 passes through the first waste alkali liquid separator 2 and the second waste alkali liquid separator 3, a water washing and separation process device of a water washing extraction tower 4 is designed. Through data calculation, the pure water added to the top of the water washing extraction tower 4 and the continuous water phase in the tower are in countercurrent contact with the organic phase, so that the intermediate phase polymer is fully in contact with the water phase and aggregated at the interface and the inorganic phase. Then the organic phase passes through the third waste alkali separator and the hydrocyclone separator 6 to separate the saturated inorganic phase carried.

[0020] Priority, such as Figure 1 As shown, the bottom discharges of the first waste alkali liquid separator 2 and the second waste alkali liquid separator 3 are respectively connected to the cyclohexane oxidation decomposition system 1, the bottom discharges of the water washing extraction tower 4 and the third waste alkali liquid separator 5 are connected to the cyclohexane oxidation decomposition system 1 after merging, and the bottom discharge of the hydrocyclone 6 is connected to the cyclohexane oxidation decomposition system 1 after merging with the bottom discharges of the water washing extraction tower 4 and the third waste alkali liquid separator 5. The first waste alkali liquid separator 2, the second waste alkali liquid separator 3, the water washing extraction tower 4, the third waste alkali liquid separator 5 and the hydrocyclone 6 are connected to the cyclohexane oxidation decomposition system 1 to recover and reprocess the residual materials.

[0021] Preferably, Figure 1 As shown, a flow detector 9 and a control regulating valve 10 are provided at the feed of the first waste alkali liquid separator 2 and the pure water pipeline 8, and an interface detector 11 is installed in the first waste alkali liquid separator 2, the second waste alkali liquid separator 3, the water washing extraction tower 4, the third waste alkali liquid separator 5 and the hydrocyclone 6. The flow of the front end liquid pipe of the first waste alkali liquid separator 2 and the water washing extraction tower 4 is adjusted by the data of the interface detector 11 to control the operation of the entire separation system.

[0022] Preferably, the flow detector 9 and the control regulating valve 10 are both connected to a centralized control system for automatic control, thereby improving the stability and automatic control of production operation.

[0023] The pure water pipeline 8 is also connected to the third waste alkali liquid separator 5 to separate and supplement water for the third waste alkali liquid separator 5 .

[0024] The technical principle is: the 0.85MPa (g) decomposition liquid from the cyclohexane oxidation decomposition system 1 passes through the flow detector 9 and the control regulating valve 10 and enters the first waste alkali liquid separator 2 and the second waste alkali liquid separator 3 in turn, and most of the separated inorganic phases are sent to the 0.35-0.4MPa (g) cyclohexane oxidation decomposition system 1 access point through the flow detector 9 and the control regulating valve 10. The organic phase discharged from the top of the second waste alkali liquid separator 3 enters the water washing extraction tower 4, contacts with the continuous water phase in the tower and the pure water at the top through the flow detector 9 and the control regulating valve 10, and separates the alkaline water intermediate phase and the inorganic phase. The organic phase discharged from the top of the water washing extraction tower 4 is further separated from the saturated inorganic phase carried in the organic phase through the third waste alkali liquid separator 5 and the hydrocyclone 6. The inorganic phases separated at the bottom of the water washing extraction tower 4, the third waste alkali liquid separator 5, and the hydrocyclone 6 are respectively sent to the access point of the cyclohexane oxidation decomposition system 1 through the control interface of the control regulating valve 10.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A cyclohexane oxidation process waste alkali water intermediate phase separation device, characterized in that: The invention comprises a first waste alkali liquid separator, a second waste alkali liquid separator, a water washing extraction tower, a third waste alkali liquid separator and a hydrocyclone separator which are connected in sequence through pipelines. The first waste alkali liquid separator is connected to the decomposition liquid from the cyclohexane oxidation decomposition system, the hydrocyclone separator is connected to the cyclohexane recovery system, and the top of the water washing extraction tower is connected to the pure water pipeline.

2. A cyclohexane oxidation process waste alkali-water intermediate phase separation device according to claim 1, characterized in that: The bottom discharges of the first waste alkali liquid separator and the second waste alkali liquid separator are respectively connected to the cyclohexane oxidation decomposition system, the bottom discharges of the water washing extraction tower and the third waste alkali liquid separator are connected to the cyclohexane oxidation decomposition system after being merged, and the bottom discharge of the cyclone separator is connected to the cyclohexane oxidation decomposition system after being merged with the bottom discharges of the water washing extraction tower and the third waste alkali liquid separator.

3. A cyclohexane oxidation process waste alkali-water intermediate phase separation device according to claim 1, characterized in that: The front ends of the first waste alkali liquid separator and the water-washing extraction tower are provided with flow detectors and control regulating valves, and the first waste alkali liquid separator, the second waste alkali liquid separator, the water-washing extraction tower, the third waste alkali liquid separator and the hydrocyclone separator are all equipped with interface detectors.

4. A cyclohexane oxidation process waste alkali-water intermediate phase separation device according to claim 3, characterized in that: The flow detector and the control regulating valve are both connected to a centralized control system for automatic control.

Images