Variable pressure rectification device for separating phenoxyethanol and phenol

Abstract

The utility model discloses a variable-pressure rectification device for separating phenoxyethanol and phenol, which comprises a high-pressure rectification tower and a normal-pressure rectification tower, a high-pressure rectification condenser and a high-pressure rectification reboiler are mounted on the high-pressure rectification tower, and a normal-pressure rectification condenser and a normal-pressure rectification reboiler are mounted on the normal-pressure rectification tower; an outlet of the high-pressure rectification condenser is provided with two branches, one branch is connected with a reflux inlet of the high-pressure rectification tower, and the other branch is connected with a feed inlet of the normal-pressure rectification tower; an outlet of the normal-pressure rectification condenser is provided with two branches, one branch is connected with a reflux inlet of the normal-pressure rectification tower, and the other branch is connected with a feed inlet of the high-pressure rectification tower. By adopting pressure swing distillation, the phenoxyethanol and phenol mixture is effectively separated, the separation effect is better, the advantages are obvious, and the pressure swing distillation device has very strong practicability.

Description

Technical Field

[0001] This utility model relates to a chemical apparatus, and more particularly to a pressure swing distillation apparatus for separating phenoxyethanol and phenol. Background Technology

[0002] Pharmaceutical-grade phenoxyethanol has stricter manufacturing requirements, higher purity requirements, and lower impurity content compared to industrial-grade phenoxyethanol. Therefore, trace amounts of phenol need to be removed during the production of pharmaceutical-grade phenoxyethanol to improve its purity.

[0003] CN104926618A discloses a method for preparing phenoxyethanol, but the phenoxyethanol obtained by this method has too low purity and contains many impurities, making it unsuitable for pharmaceutical applications. CN110642706A discloses a method for preparing high-purity phenoxyethanol, which employs organic solvent dissolution and extraction, alkaline water washing, and cooling crystallization processes. This method suffers from numerous problems, including cumbersome process steps, numerous pieces of equipment, complex operation, large solvent consumption, increased equipment investment and space requirements, and the generation of large amounts of waste liquid, causing environmental pollution. CN218146432U discloses a high-purity phenoxyethanol purification device that uses a falling film evaporator. However, the high evaporation temperature easily causes the material to generate other impurities due to heat sensitivity, and it also consumes a lot of energy and produces low purity.

[0004] This utility model device is designed primarily to solve the above problems. Summary of the Invention

[0005] This utility model provides a pressure swing distillation device that can effectively separate phenoxyethanol and phenol to solve the technical problems existing in the prior art. It includes a high-pressure distillation column and an atmospheric distillation column connected in series. A high-pressure distillation condenser is installed at the top of the high-pressure distillation column and a high-pressure distillation reboiler is installed at the bottom of the high-pressure distillation column. An atmospheric distillation condenser is installed at the top of the atmospheric distillation column and an atmospheric distillation reboiler is installed at the bottom of the atmospheric distillation column.

[0006] The aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol includes both high-pressure and atmospheric distillation columns as plate distillation columns. The trays of both the high-pressure and atmospheric distillation columns have rows of inclined perforations, and the opening directions of adjacent rows of inclined perforations are different.

[0007] In the aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol, the tray holes are rectangular or triangular.

[0008] In the aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol, the inlet of the high-pressure distillation condenser is the top outlet of the high-pressure distillation column. The outlet of the high-pressure distillation condenser has two branches: branch I is connected to the reflux port of the high-pressure distillation column, and branch II is connected to the atmospheric distillation column. The bottom outlet of the high-pressure distillation column is the inlet of the high-pressure distillation reboiler. The outlet of the high-pressure distillation reboiler has two branches: branch III returns to the high-pressure distillation column, and branch IV is the outlet for high-purity phenoxyethanol.

[0009] In the aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol, the inlet of the atmospheric distillation column is branch II of the high-pressure distillation condenser. The outlet of the atmospheric distillation condenser has two branches: branch V refluxes back to the feed inlet of the high-pressure distillation column, both entering the feed inlet of the high-pressure distillation column; branch II is the reflux port of the atmospheric distillation column; the bottom outlet of the atmospheric distillation column is the inlet of the atmospheric distillation reboiler; the outlet of the atmospheric distillation reboiler has two branches: branch VII refluxes back to the atmospheric distillation column; and branch VIII is the system phenol outlet.

[0010] The aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol includes a pressure gauge and a thermometer on the high-pressure distillation column; a pressure gauge and a thermometer on the atmospheric distillation column; and a flow meter and a regulating valve installed on the feed inlet branch of the atmospheric distillation condenser returning to the high-pressure distillation column.

[0011] In the aforementioned pressure swing distillation apparatus for separating phenoxyethanol and phenol, a regulating valve is installed on the branch line from the high-pressure distillation condenser to the atmospheric distillation column, a regulating valve is installed on the branch line from the high-pressure distillation reboiler to the high-pressure distillation column, and a regulating valve is installed on the branch line from the atmospheric distillation reboiler to the atmospheric distillation column.

[0012] The advantages and positive effects of this invention are as follows: by using pressure swing distillation, the mixture of phenoxyethanol and phenol is effectively separated with good separation effect and a purity of 99.99%; the use of a slanted perforated tray structure effectively improves production capacity and efficiency while reducing production costs; it is also simple in structure, requires few devices, is inexpensive, easy to implement, and highly practical; it does not use solvents, generates no waste, and is environmentally friendly and efficient.

[0013] Both the high-pressure distillation column 1 and the atmospheric distillation column 3 can be plate distillation columns or packed distillation columns. In this embodiment, both the high-pressure distillation column 1 and the atmospheric distillation column 3 are plate distillation columns. The perforations on the plates are arranged in rows of oblique openings, which facilitates gas ejection from the opening direction. Simultaneously, the perforations are simple to manufacture, less prone to damage, reduce manufacturing costs, and increase the service life of the equipment. The staggered arrangement of the openings in adjacent rows of perforations on the plates creates highly turbulent gas-liquid flow. This not only reduces mist entrainment and eliminates upward airflow, but also ensures sufficient gas-liquid contact, thereby achieving good mass transfer. The oblique perforations are rectangular or triangular, facilitating processing. Compared with the bubble cap plates and floating valve plates used in traditional pressure swing distillation, the production capacity of oblique perforated plates is 30%-50% higher, the structure is much simpler, the relative cost is lower, and the manufacturing process is convenient, making it highly applicable in industrial applications.

[0014] In summary, pressure swing distillation avoids the recovery of the extractant and the separation of the azeotropic agent, and has the advantages of a short process flow, low equipment investment, convenient operation, and easy control. It has great potential for industrial applications. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the structure of the high-pressure distillation column and the atmospheric distillation column of this utility model, where the tray holes are triangular.

[0017] Figure 3 This is a schematic diagram of the structure of the high-pressure distillation column and the atmospheric distillation column of this utility model, where the trays have rectangular holes.

[0018] In the diagram: 1. High-pressure distillation column, 11. Top outlet I, 12. Bottom outlet I, 2. High-pressure distillation condenser, 21. Branch I, 22. Branch II, 3. Atmospheric distillation column, 31. Top outlet II, 32. Bottom outlet II, 4. Atmospheric distillation condenser, 41. Branch V, 411. Branch I, 412. Branch II, 5. High-pressure distillation reboiler, 51. Branch III, 52. Branch IV, 6. Atmospheric distillation reboiler, 61. Branch VII, 62. Branch VIII. Detailed Implementation

[0019] To further understand the invention content, features, and effects of this utility model, the following detailed description is provided in conjunction with the following embodiments and accompanying drawings:

[0020] like Figure 1As shown, the system includes a high-pressure distillation column 1 and an atmospheric distillation column 5. The high-pressure distillation column 1 is equipped with a high-pressure distillation condenser 2 and a high-pressure distillation reboiler 5. The inlet of the high-pressure distillation condenser 2 is the top outlet I11 of the high-pressure distillation column 1. The outlet of the high-pressure distillation condenser 2 has two branches: branch I21 is connected to the reflux port of the high-pressure distillation column 1, and branch II22 goes to the atmospheric distillation column 3. The bottom outlet I12 of the high-pressure distillation column 1 is the inlet of the high-pressure distillation reboiler 5. The outlet of the high-pressure distillation reboiler 5 has two branches: branch III51 returns to the high-pressure distillation column 1, and branch IV52 is the outlet of high-purity phenoxyethanol. The atmospheric distillation column 3 is equipped with an atmospheric distillation condenser 4 and an atmospheric distillation reboiler 6. The inlet of the atmospheric distillation column 3 is branch 22 of the high-pressure distillation condenser 2. Branch V41 of the atmospheric distillation condenser 4 has two branches: branch I 411 returns to inlet 70 and enters the material inlet 71 of the high-pressure distillation column 1; branch II 412 is the reflux port of the atmospheric distillation column 3. The bottom outlet II 32 of the atmospheric distillation column 3 is the inlet of the atmospheric distillation reboiler 6. The outlet of the atmospheric distillation reboiler 6 has two branches: branch VII 61 returns to the atmospheric distillation column 3, and branch VIII 62 is the system phenol outlet. The high-pressure distillation column 1 has a pressure gauge P1 and a thermometer P2. The atmospheric distillation column 3 has a pressure gauge P3 and a thermometer P3. Branch I 411 is equipped with a flow meter M1 and a regulating valve FV1. Branch I 21 is equipped with a regulating valve FV3. A regulating valve FV2 is installed on branch line III51. A regulating valve FV4 is installed on branch line VII61.

[0021] Both the high-pressure distillation column and the atmospheric distillation column are plate distillation columns. The trays of both columns have rows of inclined perforations, and the opening directions of adjacent rows of inclined perforations are different. Figures 2-3 As shown.

[0022] The inclined plate hole is rectangular or triangular. Example 1

[0023] A mixture of phenoxyethanol and phenol is fed into high-pressure distillation column 1 for high-pressure distillation. The phenoxyethanol product obtained at the bottom of the column is reboiled in high-pressure distillation reboiler 5 and discharged through branch IV 52, with a portion returning to high-pressure distillation column 1 via branch III 51. The azeotrope A1 of phenoxyethanol and phenol is obtained at the top of the column. This azeotrope A1 enters high-pressure distillation condenser 2, with a portion returning to high-pressure distillation column 1 as reflux and the other portion being fed into atmospheric distillation column 3. The azeotrope A1 of phenoxyethanol and phenol... Atmospheric distillation is carried out in atmospheric distillation column 3. The phenol product obtained at the bottom of the column, with higher purity, is reboiled in atmospheric distillation reboiler 6 and discharged from branch VIII 62. A portion is refluxed back to atmospheric distillation column 3 via branch VII 61. An azeotrope of phenoxyethanol and phenol, A2, is obtained at the top of the column. This azeotrope A2 enters atmospheric distillation condenser 4. Part of it is returned to atmospheric distillation column 3 as reflux, and the other part is fed into high-pressure distillation column 1. Since the phenol content in azeotrope A1 is greater than that in azeotrope A2, the flow rates are adjusted in real-time using relevant regulating valves by analyzing the contents of phenoxyethanol and phenol at material inlet 70, phenoxyethanol outlet 52, and phenol outlet 62. Phenoxyethanol in the system continuously accumulates at the bottom of atmospheric distillation reboiler 6, while phenoxyethanol accumulates at the bottom of high-pressure distillation column 1 and is produced.

[0024] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above, which are merely illustrative and not restrictive.

Claims

1. A pressure swing distillation apparatus for separating phenoxyethanol and phenol, characterized in that, It includes a high-pressure distillation column (1) and an atmospheric distillation column (3) connected in series. The high-pressure distillation column (1) is equipped with a high-pressure distillation condenser (2) at the top and a high-pressure distillation reboiler (5) at the bottom. The atmospheric distillation column (3) is equipped with an atmospheric distillation condenser (4) at the top and an atmospheric distillation reboiler (6) at the bottom.

2. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 1, characterized in that, Both the high-pressure distillation column (1) and the atmospheric distillation column (3) are plate distillation columns. The plates of both the high-pressure distillation column (1) and the atmospheric distillation column (3) have rows of inclined plates with different opening directions for adjacent rows of inclined plates.

3. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 2, characterized in that, The tray holes are rectangular or triangular.

4. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 1, characterized in that, The inlet of the high-pressure distillation condenser (2) is the top outlet of the high-pressure distillation column (1). The outlet of the high-pressure distillation condenser (2) has two branches. Branch I (21) is connected to the reflux port of the high-pressure distillation column (1), and branch II (22) is connected to the atmospheric distillation column (3). The bottom outlet of the high-pressure distillation column (1) is the inlet of the high-pressure distillation reboiler (5). The outlet of the high-pressure distillation reboiler (5) has two branches. Branch III (51) refluxes back to the high-pressure distillation column (1), and branch IV (52) is the outlet of high-purity phenoxyethanol.

5. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 4, characterized in that, The inlet of the atmospheric distillation column (3) is branch II (22) of the high-pressure distillation condenser (2). The outlet of the atmospheric distillation condenser (4) has two branches. Branch V (41) flows back to the raw material inlet of the high-pressure distillation column (1) and enters the material inlet of the high-pressure distillation column together. Branch II (412) is the reflux port of the atmospheric distillation column. The bottom outlet of the atmospheric distillation column is the inlet of the atmospheric distillation reboiler (6). The outlet of the atmospheric distillation reboiler (6) has two branches. Branch VII (61) flows back to the atmospheric distillation column (3), and branch VIII (62) is the phenol outlet of the system.

6. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 5, characterized in that, The high-pressure distillation column (1) has a pressure gauge and a thermometer; the atmospheric distillation column (3) has a pressure gauge and a thermometer; the atmospheric distillation condenser (4) has a flow meter and a regulating valve installed on the feed inlet branch of the high-pressure distillation column.

7. The pressure swing distillation apparatus for separating phenoxyethanol and phenol according to claim 6, characterized in that, A regulating valve is installed on the branch line from the high-pressure distillation condenser (2) to the atmospheric distillation column (3), a regulating valve is installed on the branch line from the high-pressure distillation reboiler (5) to the high-pressure distillation column (1), and a regulating valve is installed on the branch line from the atmospheric distillation reboiler (6) to the atmospheric distillation column (3).

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