Negative pressure tower ethanol purification system

Abstract

The negative pressure tower ethanol purification system comprises a negative pressure tower, a rectifying tower, a reflux tank and a vacuum unit, one end of a gas phase outlet pipe at the top of the negative pressure tower is connected with the rectifying tower, one end of a gas phase outlet pipe at the top of the rectifying tower is connected with a condenser through a condensation pipe, and one end of a discharge pipe of the condenser is connected with the reflux tank; one end of the return tank discharging pipe is connected with a finished product collecting tank. Under the action of negative pressure, an ethanol material mixed with isopropanol and 2-pentanone is introduced into the negative pressure tower, the isopropanol and ethanol are gasified and enter the rectifying tower for rectification, the 2-pentanone flows downwards and is discharged through the first liquid phase discharge pipe, the ethanol is gasified and is condensed through the condenser and then enters the reflux tank, and the isopropanol flows downwards and is discharged through the second liquid phase discharge pipe. In a negative pressure environment, light components and heavy components can be more quickly enriched towards the tower top or the tower bottom, the separation time is shortened, meanwhile, the system pressure is reduced, the boiling point of materials can be obviously reduced, and heat required by separation can be reduced. And through cooperation of the negative pressure tower and the rectifying tower, the ethanol purification effect and efficiency can be improved.

Description

Technical Field

[0001] This utility model relates to the field of ethanol purification technology, and in particular to a negative pressure tower ethanol purification system. Background Technology

[0002] Ethanol, as a basic industrial raw material, is an important organic solvent and chemical feedstock, widely used in energy, medical, food, chemical, and electronics industries. Different purities of ethanol (such as industrial grade, food grade, pharmaceutical grade, and electronic grade) have different uses and functions. Its widespread application depends on its solubility, volatility, bactericidal properties, and renewability; different industries have significantly different purity requirements.

[0003] In actual production, ethanol is mixed with byproducts such as isopropanol and 2-pentanone. Therefore, ethanol needs to be purified. However, most existing purification methods are carried out under normal pressure, resulting in poor purification effect. Furthermore, directly condensing ethanol vapor cannot effectively remove the mixed byproducts, thus affecting the purification effect and efficiency. Utility Model Content

[0004] The purpose of this application is to provide a negative pressure tower ethanol purification system to solve the problems of poor purification effect and inability to effectively remove mixed by-products in existing purification methods, which in turn affect the purification effect and efficiency.

[0005] To solve the above-mentioned technical problems, this application provides a negative pressure tower ethanol purification system, comprising:

[0006] The system comprises a negative pressure column, a distillation column, a reflux tank, and a vacuum unit. The top of the negative pressure column is connected to the vacuum unit via a vacuum pipe. One end of the vapor phase outlet pipe at the top of the negative pressure column is connected to the distillation column. One end of the vapor phase outlet pipe at the top of the distillation column is connected to a condenser via a condenser pipe. One end of the discharge pipe of the condenser is connected to the reflux tank. One end of the discharge pipe of the reflux tank is connected to a finished product collection tank. Both the distillation column and the negative pressure column are connected to reboilers at their lower parts. The bottom of the negative pressure column is connected to a first liquid phase manifold, and the bottom of the distillation column is connected to a second liquid phase manifold.

[0007] In a preferred embodiment, a negative pressure tower ethanol purification system is provided, wherein a reflux pipe is also connected to the discharge pipe, one end of the reflux pipe is connected to the upper part of one side of the negative pressure tower, and a reflux pump and a reflux control valve are provided on the reflux pipe.

[0008] The solution requires detailed explanation of a negative pressure tower ethanol purification system, wherein the reflux tank is also provided with an insulation layer on its outer side.

[0009] In a preferred embodiment, a negative pressure tower ethanol purification system is provided, wherein one end of the first liquid phase pipe and the second liquid phase pipe are respectively connected to a by-product collection tank via a pump.

[0010] The solution requires further explanation. In a negative pressure tower ethanol purification system, pressure sensors and temperature sensors are also installed on the negative pressure tower and the distillation tower.

[0011] Compared with the prior art, the negative pressure tower ethanol purification system provided by this utility model includes a negative pressure tower, a distillation tower, a reflux tank, and a vacuum unit. The top of the negative pressure tower is connected to the vacuum unit through a vacuum pipe. One end of the vapor phase outlet pipe at the top of the negative pressure tower is connected to the distillation tower. One end of the vapor phase outlet pipe at the top of the distillation tower is connected to a condenser through a condenser pipe. One end of the discharge pipe of the condenser is connected to the reflux tank. One end of the discharge pipe of the reflux tank is connected to a finished product collection tank. Both the bottom of the distillation tower and the negative pressure tower are connected to reboilers. The bottom of the negative pressure tower is connected to a first liquid phase pipe, and the bottom of the distillation tower is connected to a second liquid phase pipe. In operation, a vacuum unit provides negative pressure to the negative pressure tower. Ethanol mixed with isopropanol and 2-pentanone is fed into the negative pressure tower. Isopropanol and ethanol vaporize and enter the rectification tower for distillation. 2-Pentanone flows downwards and is discharged through the first liquid phase drain pipe. Based on the boiling point difference between isopropanol and ethanol, ethanol vaporizes and enters the condenser through the condenser before condensation and entering the reflux tank. Finally, it flows through the discharge pipe into the finished product collection tank, while isopropanol flows downwards and is discharged through the second liquid phase drain pipe. In a negative pressure environment, the light components isopropanol and ethanol, and the heavy component 2-pentanone, are more quickly enriched at the top or bottom of the tower, shortening the separation time. Simultaneously, the reduced system pressure significantly lowers the boiling point of the materials, reducing the heat required for separation and avoiding the decomposition of heat-sensitive substances or energy waste caused by high temperatures. Furthermore, the combination of the negative pressure tower and the rectification tower improves the purification effect and efficiency of ethanol. Attached Figure Description

[0012] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0013] Figure 1 This is a schematic diagram of a negative pressure tower ethanol purification system provided in an embodiment of this application;

[0014] In the diagram: 1. Negative pressure tower; 2. Distillation tower; 3. Reflux tank; 4. Vacuum unit; 5. Vacuum tube; 6. Condenser tube; 7. Condenser; 8. Discharge pipe; 9. Finished product collection tank; 10. Reboiler; 11. First liquid phase pipe; 12. Second liquid phase pipe; 13. Reflux pipe; 14. Reflux pump; 15. Reflux control valve; 16. Insulation layer; 17. Pump; 18. By-product collection tank; 19. Pressure sensor; 20. Temperature sensor. Detailed Implementation

[0015] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0016] The core of this application is to provide a negative pressure tower ethanol purification system, which solves the problem that existing purification methods have poor purification effect and cannot effectively remove mixed by-products, thus affecting the purification effect and efficiency.

[0017] Figure 1 This is a schematic diagram of a negative pressure tower ethanol purification system provided in an embodiment of this application. See also... Figure 1 As shown.

[0018] Example 1

[0019] A negative pressure ethanol purification system includes a negative pressure tower 1, a distillation tower 2, a reflux tank 3, and a vacuum unit 4. The top of the negative pressure tower 1 is connected to the vacuum unit 4 via a vacuum pipe 5, which provides negative pressure to the negative pressure tower 1. One end of the vapor phase outlet pipe at the top of the negative pressure tower 1 is connected to the distillation tower 2. Both the distillation tower 2 and the lower part of the negative pressure tower 1 are connected to reboilers 10. The bottom of the negative pressure tower 1 is connected to a first liquid phase outlet pipe 11. In use, the mixture (isopropanol, 2-pentanone, and ethanol) first enters the negative pressure tower 1. According to the difference in boiling points, isopropanol and ethanol are heated and vaporized, rising and entering the distillation tower 2 through the vapor phase outlet pipe at the top of the negative pressure tower 1. 2-Pentanone accumulates at the bottom of the negative pressure tower 1 and is finally discharged through the first liquid phase outlet pipe 11. One end of the top vapor outlet pipe of distillation column 2 is connected to condenser 7 via condenser pipe 6. One end of the outlet pipe of condenser 7 is connected to reflux tank 3. One end of the discharge pipe 8 of reflux tank 3 is connected to product collection tank 9. In distillation column 2, ethanol is heated and vaporized, rises and enters condenser 7 through condenser pipe 6 for condensation. After condensation, the ethanol enters reflux tank 3 for temporary storage and then enters product collection tank 9. Isopropanol is enriched at the bottom of distillation column 2. The bottom of distillation column 2 is connected to a second liquid phase outlet pipe 12, and finally discharged from the second liquid phase outlet pipe 12. Thus, isopropanol, 2-pentanone and ethanol can be separated to purify ethanol.

[0020] The negative pressure column 1 and distillation column 2 can be made of high-hardness materials to improve their pressure resistance and prevent dents and deformation, thus ensuring long-term stable operation of the system. Because the boiling point of ethanol decreases under negative pressure, the heating steam temperature required for the reboiler 10 also decreases. Low-grade heat sources (such as waste heat or hot water) can be used to replace traditional high-temperature steam, thereby reducing steam consumption by 30%–50%.

[0021] Based on Example 1, a negative pressure tower ethanol purification system is preferably provided, wherein a reflux pipe 13 is also connected to the discharge pipe 8, one end of the reflux pipe 13 is connected to the upper part of one side of the negative pressure tower 1, and a reflux pump 14 and a reflux control valve 15 are provided on the reflux pipe 13. When incomplete condensation or system pressure fluctuations result in the presence of a small amount of uncondensed ethanol gas, the reflux control valve 15 can be opened to separate the gas under the action of the reflux pump 14 and discharge it back into the negative pressure tower 1 through the reflux pipe 13.

[0022] Based on Example 1, a negative pressure tower ethanol purification system is preferably provided with a heat insulation layer 16 on the outside of the reflux tank 3. This can prevent the partial vaporization of low-temperature ethanol (liquid) after absorbing ambient heat.

[0023] Based on Example 1, a negative pressure tower ethanol purification system, preferably, has a by-product collection tank 18 connected to one end of the first liquid phase pipe 11 and the second liquid phase pipe 12 via a pump 17 to facilitate the collection of by-products. In use, the corresponding products (isopropanol, 2-pentanone) can be collected through the by-product collection tank 18.

[0024] Based on Example 1, a negative pressure tower ethanol purification system is provided. Preferably, a pressure sensor 19 and a temperature sensor 20 are also installed on the negative pressure tower 1 and distillation tower 2 to facilitate the monitoring of pressure and temperature within them. This ensures stable system operation and prevents a decrease in separation efficiency or production accidents caused by pressure fluctuations.

[0025] In actual use, it is essential to strictly ensure the sealing of components such as negative pressure tower 1 and distillation tower 2 to prevent outside air from seeping in, which could affect the vacuum level or cause the system to be contaminated.

[0026] The present invention provides a negative pressure tower ethanol purification system, comprising a negative pressure tower 1, a distillation tower 2, a reflux tank 3, and a vacuum unit 4. The top of the negative pressure tower 1 is connected to the vacuum unit 4 via a vacuum pipe 5. One end of the top vapor phase outlet pipe of the negative pressure tower 1 is connected to the distillation tower 2. One end of the top vapor phase outlet pipe of the distillation tower 2 is connected to a condenser 7 via a condenser pipe 6. One end of the discharge pipe of the condenser 7 is connected to the reflux tank 3. One end of the discharge pipe 8 of the reflux tank 3 is connected to a finished product collection tank 9. Both the distillation tower 2 and the negative pressure tower 1 are connected to a reboiler 10 at their lower parts. The bottom of the negative pressure tower 1 is connected to a first liquid phase outlet pipe 11, and the bottom of the distillation tower 2 is connected to a second liquid phase outlet pipe 12. In operation, vacuum unit 4 provides negative pressure to negative pressure tower 1, and ethanol mixed with isopropanol and 2-pentanone is fed into negative pressure tower 1. Isopropanol and ethanol vaporize and enter distillation tower 2 for rectification. 2-Pentanone flows downward and is discharged through the first liquid phase drain pipe 11. Based on the boiling point difference between isopropanol and ethanol, ethanol vaporizes and enters condenser 7 through condenser pipe 6 for condensation before entering reflux tank 3. Finally, it enters product collection tank 9 through discharge pipe 8, and isopropanol flows downward and is discharged through the second liquid phase drain pipe 12. In a negative pressure environment, the light components isopropanol and ethanol and the heavy component 2-pentanone are more quickly enriched at the top or bottom of the tower, shortening the separation time. At the same time, the system pressure is reduced, and the boiling point of the materials decreases significantly, which can reduce the heat required for separation and avoid the decomposition of heat-sensitive substances or energy waste caused by high temperatures. Furthermore, the cooperation between negative pressure tower 1 and distillation tower 2 can improve the purification effect and efficiency of ethanol.

[0027] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and incorporate common knowledge or customary techniques in the art disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

[0028] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The embodiments of this application described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A negative pressure column ethanol purification system, characterized in that, The utility model relates to a kind of vacuum distillation tower, including: Negative pressure tower (1), rectifying tower (2), reflux tank (3) and vacuum unit (4), the top of the negative pressure tower (1) is connected with the vacuum unit (4) by vacuum pipe (5), the top of the negative pressure tower (1) gas phase outlet pipe one end is connected with rectifying tower (2), the top of the rectifying tower (2) gas phase outlet pipe one end is connected with condenser (7) by condensing pipe (6), the discharge pipe one end of the condenser (7) is connected with reflux tank (3), the discharge pipe (8) one end of the reflux tank (3) is connected with finished product collection tank (9), the rectifying tower (2) and the lower portion of the negative pressure tower (1) are connected with reboiler (10), the bottom of the negative pressure tower (1) is connected with first liquid phase discharge pipe (11), the bottom of the rectifying tower (2) is connected with second liquid phase discharge pipe (12).

2. The system of claim 1, wherein, The discharge pipe (8) is also communicated with reflux pipe (13), one end of the reflux pipe (13) is connected with the upper portion of one side of the negative pressure tower (1), reflux pump (14) and reflux control valve (15) are provided on the reflux pipe (13).

3. The system of claim 1, wherein, The outer side of the reflux tank (3) is also provided with heat preservation layer (16).

4. The system of claim 1, wherein, One end of the first liquid phase discharge pipe (11) and the second liquid phase discharge pipe (12) is also connected with by-product collection tank (18) respectively through pump (17).

5. The system of claim 1, wherein, The negative pressure tower (1) and the rectifying tower (2) are also provided with pressure sensor (19) and temperature sensor (20).

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