An energy-saving dehydration system for producing anhydrous alcohol

Abstract

This application relates to a dehydration and energy-saving system for producing anhydrous ethanol, belonging to the technical field of ethanol production. It includes a molecular sieve and a recovery tower. One end of the molecular sieve is connected to the top of the recovery tower via a superheater, and the other end of the molecular sieve is sequentially connected to a compressor, a regeneration superheater, a reboiler, and the recovery tower. This energy-saving system for producing anhydrous ethanol significantly improves thermal efficiency and reduces system energy consumption and production costs through full heat recovery and utilization and rational equipment selection. Simultaneously, the entire process flow is compactly designed, and the equipment selection is optimized, ensuring high purity and high yield of anhydrous ethanol, resulting in significant energy savings and economic benefits. The steam consumption per ton of anhydrous ethanol in this process is approximately 160 kg, saving 75% compared to traditional processes. The circulating water required per ton of anhydrous ethanol in this process is approximately 18 tons, saving 64% compared to traditional processes.

Description

Technical Field

[0001] This application relates to the technical field of alcohol production, and in particular to a dehydration and energy-saving system for producing anhydrous alcohol. Background Technology

[0002] Currently, anhydrous ethanol is an important chemical product in the alcohol production industry, widely used in pharmaceuticals, chemicals, and fuels. However, traditional methods for producing anhydrous ethanol suffer from significant energy consumption problems, especially in the molecular sieve dehydration and distillate recovery processes. Existing processes typically dehydrate alcohol vapor using molecular sieves, extracting the dehydrated product from the bottom of the sieve through adsorption. This product is then condensed into liquid by a condenser to obtain anhydrous ethanol, and the resulting distillate is sent to a recovery tower for concentration. To maintain distillation operations in the recovery tower, the bottom is heated with high-temperature steam via a reboiler. However, this method has low energy efficiency, mainly in the following aspects: the latent heat of the ethanol extracted through the molecular sieve is not well utilized but is directly released into the environment through cooling equipment, resulting in a significant waste of potential heat energy. The reboiler in the recovery tower requires a large amount of high-temperature steam to heat the alcohol solution at the bottom of the tower; the steam consumption for each ton of anhydrous ethanol production reaches as high as 650 kg, significantly increasing production costs.

[0003] Patent CN217661572 U discloses an energy-saving device for producing anhydrous alcohol using molecular sieves. This device includes two reboilers. The first reboiler absorbs some of the heat from the dehydrated alcohol gas and supplies it to a recovery tower, thereby reducing the amount of steam supplied to the recovery tower by the second reboiler and saving steam consumption. However, while the first reboiler recovers some of the latent heat of the dehydrated alcohol gas, its heat supply capacity is limited, and it remains highly dependent on the supplementary heat from the second reboiler. Furthermore, while adding a reboiler saves energy, it increases the complexity of the system and consequently increases operating and maintenance costs. Especially when heat recovery is incomplete, the energy-saving effect may not outweigh the cost of the additional equipment. Utility Model Content

[0004] To overcome the shortcomings of existing technologies, this application provides a dehydration and energy-saving system for producing anhydrous alcohol, employing the following technical solution:

[0005] A dehydration and energy-saving system for producing anhydrous alcohol includes a molecular sieve and a recovery tower. One end of the molecular sieve is connected to the top of the recovery tower via a superheater, and the other end of the molecular sieve is connected in sequence via a compressor, a regeneration superheater, a reboiler, and the recovery tower.

[0006] By adopting the above technical solution, the concentrated alcohol gas at the top of the recovery tower is first heated by a superheater before entering the molecular sieve. After the alcohol gas is dehydrated by the molecular sieve, the pressure and temperature are increased by a compressor. The regeneration superheater further heats the anhydrous alcohol, raising the temperature of the alcohol gas before it is sent to the recovery tower. The alcohol gas heated by the regeneration superheater provides an efficient heat source for the recovery tower, significantly reducing the demand for external steam at the bottom of the tower and further optimizing heat distribution. At the same time, the heat energy of the alcohol gas is fully recovered and utilized during the compression and heating process, maximizing the thermal efficiency of the entire system, reducing energy consumption and production costs.

[0007] Preferably, the outlet of the molecular sieve is connected sequentially through a condenser assembly, a distillation tank, and the lower part of a recovery tower.

[0008] By adopting the above technical solution, the diluted wine separated by molecular sieve is sent to the lower part of the recovery tower for concentration.

[0009] Preferably, a booster pump is installed between the light wine tank and the recovery tower.

[0010] Preferably, the condenser assembly and the vacuum pump assembly are connected.

[0011] Preferably, the compressor is a screw compressor.

[0012] Preferably, the outlet of the reboiler is connected to the cooler via a storage tank.

[0013] Preferably, a booster pump is provided between the storage tank and the cooler.

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

[0015] 1. By setting up a compressor and a regenerating superheater, the alcohol gas exiting the molecular sieve is further heated by the compressor and the regenerating superheater to increase the temperature and pressure, providing an efficient heat source for subsequent processes. After the alcohol gas heated by the regenerating superheater enters the recovery tower, the demand for external steam at the bottom of the tower is significantly reduced, thus reducing the total energy consumption of the system. During the compression and heating process, thermal energy is efficiently recovered and reused, maximizing the thermal efficiency of the entire system.

[0016] 2. The energy-saving system for producing anhydrous ethanol of the present invention significantly improves thermal efficiency and reduces system energy consumption and production costs through full heat recovery and utilization and reasonable equipment selection. At the same time, the entire process flow is compactly designed and the equipment selection is optimized, ensuring high purity and high yield of anhydrous ethanol, and has significant energy-saving and economic benefits. The steam consumption of this process is about 160 kg per ton of anhydrous ethanol, which is 75% lower than that of the traditional process. The circulating water required for each ton of anhydrous ethanol in this process is about 18 tons, which is 64% lower than that of the traditional process.

[0017] 3. This invention, through the research of vapor compression technology and equipment, compresses dehydrated low-pressure, low-temperature anhydrous alcohol gas into high-pressure, high-temperature anhydrous alcohol vapor by mechanical means. This vapor replaces saturated water vapor to provide a heat source for the reboiler of the recovery tower, while the anhydrous alcohol vapor is condensed. This process technology not only reduces steam consumption in the process, but also reduces the condensation and cooling water consumption of the finished anhydrous alcohol. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the energy-saving system for producing anhydrous alcohol according to the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1. Molecular sieve; 2. Recovery tower; 3. Superheater; 4. Screw compressor; 5. Regeneration superheater; 6. Reboiler; 7. Condenser assembly; 8. Vacuum pump assembly; 9. Distillate tank; 10. Storage tank; 11. Cooler. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0021] This application discloses a dehydration and energy-saving system for producing anhydrous alcohol.

[0022] Reference Figure 1 An energy-saving dehydration system for producing anhydrous alcohol includes a molecular sieve 1 and a recovery tower 2. The top of the recovery tower 2 is connected to the feed end of the molecular sieve 1. The discharge end of the molecular sieve 1 is connected to the recovery tower 2 via a screw compressor 4, a regeneration superheater 5, a reboiler 6, and the recovery tower 2 in sequence. The reboiler 6 is used to heat the recovery tower 2. The liquid outlet of the molecular sieve 1 is connected to the lower middle part of the recovery tower 2 via a condenser assembly 7, a distillate tank 9, a booster pump, and the condenser assembly 7. The condenser assembly 7 is connected to a vacuum pump assembly 8. The discharge outlet of the reboiler 6 is connected to a cooler 11 via a storage tank 10, a booster pump, and the cooler 11. The cooler 11 outputs the finished alcohol.

[0023] Working Principle: During operation, 95% alcohol from the raw material tank replaces the reflux liquid in recovery tower 2 and enters the top of recovery tower 2. The working pressure at the top of recovery tower 2 is 0.1 MPa, and the temperature is 90℃, while the working pressure at the bottom is 0.12 MPa, and the temperature is 123℃. The concentrated alcohol gas at the top passes through heat exchanger 3 and enters molecular sieve 1 for adsorption and dehydration to obtain anhydrous alcohol gas. The anhydrous alcohol gas enters the screw pump compressor and regeneration superheater 5, which raises the alcohol gas pressure from 0.08 MPa to 0.5 MPa and the temperature to 132℃. It then heats recovery tower 2 through reboiler 6. Steam is used to supplement the insufficient heat from distillation in recovery tower 2. After releasing heat through reboiler 6, the anhydrous alcohol becomes liquid and, after cooling, enters the finished alcohol storage tank. The diluted alcohol desorbed from the molecular sieve 1 adsorption bed is pumped into the lower part of recovery tower 2 for concentration after passing through condenser group 7. The alcohol gas at the top, after being heated, enters molecular sieve 1 for dehydration.

Claims

1. A dehydration and energy-saving system for producing anhydrous ethanol, comprising a molecular sieve (1) and a recovery tower (2), characterized in that: One end of the molecular sieve (1) is connected to the top of the recovery tower (2) through the superheater (3), and the other end of the molecular sieve (1) is connected in sequence through the compressor, the regeneration superheater (5), the reboiler (6) and the recovery tower (2).

2. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 1, characterized in that: The outlet of the molecular sieve (1) is connected in sequence through the lower middle part of the condenser group (7), the light wine tank (9), and the recovery tower (2).

3. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 2, characterized in that: A booster pump is installed between the light wine tank (9) and the recovery tower (2).

4. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 2, characterized in that: The condenser assembly (7) and the vacuum pump assembly (8) are connected.

5. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 1, characterized in that: The compressor is a screw compressor (4).

6. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 1, characterized in that: The outlet of the reboiler (6) is connected to the cooler (11) through the storage tank (10).

7. The dehydration and energy-saving system for producing anhydrous alcohol according to claim 6, characterized in that: A booster pump is installed between the storage tank (10) and the cooler (11).

Images