Distillation process system for producing glycerol
By improving the glycerol capture system of the distillation tower and dry degassing tank, and using cooling water and heat-regulating water heat exchangers to condense and capture escaped glycerol, the problem of escape to sewage in glycerol production is solved, the glycerol yield is improved, and the sewage COD is reduced, and the environmental impact is improved.
Patent Information
- Application Number
- CN202422423480.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-10-08
AI Technical Summary
During the glycerin production process, some glycerin escapes into the sewage during the distillation of crude glycerin, resulting in the problem of lower glycerin yield and high COD in the sewage.
Using an improved process system including a distillation column, a dry degassing tank and a glycerol trap, the glycerol escapes from the distillation column and a dry degassing tank are captured by a first glycerol trap and a second glycerol trap, respectively, and condensed trapping is performed using cooling water and a heat exchanger for temperature control.
It effectively improves the glycerin yield, reduces the glycerin content and COD value in wastewater, improves production efficiency and reduces environmental pollution.
Smart Images
Figure CN223144165U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of glycerol production and processing, and particularly relates to a distillation process system for producing glycerol. Background Art
[0002] The general steps of the process for preparing glycerol by hydrolyzing oil and fat are as follows: the oil and fat are hydrolyzed to obtain fatty acid + glycerol water; the glycerol water is evaporated to obtain crude glycerol with a concentration of 80-90%; the crude glycerol is distilled and decolorized to obtain refined glycerol. During the distillation process of the crude glycerol, the crude glycerol is dried and degassed (under negative pressure, heated to 90-100 °C), and the water vapor generated by degassing is discharged into the sewage. The liquid phase then enters the distillation column for glycerol gasification (under negative pressure, heated to 160 °C). Glycerol is recovered by condensation as the middle fraction, and the light components are discharged into the sewage.
[0003] However, the applicant found through the analysis of the sewage in the production process of distilling crude glycerol that it contains about 2% glycerol, and the COD of the sewage is as high as 20000+ g / m 3 . The possible reasons for the analysis are that when the crude glycerol is dried and degassed, a part of the glycerol escapes into the sewage together with the water vapor, and another part of the glycerol escapes into the sewage together with the light components in the glycerol distillation column. Summary of the Utility Model
[0004] In order to solve the above problems in the prior art, the utility model provides a distillation process system for producing glycerol.
[0005] In order to achieve the above object, the distillation process system for producing glycerol of the utility model is mainly characterized in that it includes a distillation column, a drying and degassing tank, and a glycerol trapping device. The gas phase outlet of the distillation column is connected to the drying and degassing tank. The glycerol trapping device includes a first glycerol trap and a second glycerol trap. The top light component outlet of the distillation column is connected to the first glycerol trap to trap the glycerol escaping from the top light components of the distillation column. The water vapor outlet of the drying and degassing tank is connected to a vacuum pumping device through the second glycerol trap to trap the glycerol escaping from the water vapor outlet of the drying and degassing tank. The liquid phase generated by the drying and degassing tank is communicated to the distillation column. The first glycerol trap is a cooling water heat exchanger, and the second glycerol trap is a temperature-controlled water heat exchanger.
[0006] Preferably, a demisting mesh is provided both inside and outside the first glycerol trap.
[0007] Preferably, multiple layers of fins are provided inside the first glycerol trap.
[0008] Preferably, the first glycerol trap is provided with a cooling water inlet and a cooling water outlet.
[0009] Preferably, the second glycerol trap is provided with a temperature-controlled water inlet and a temperature-controlled water outlet.
[0010] Preferably, the top light component outlet of the distillation column is connected to the first glycerol trap through a condenser.
[0011] Preferably, a steam ejector pump is provided at the top of the first glycerol trap.
[0012] Preferably, the liquid phase generated by the drying and degassing tank is connected to the distillation column through a heater.
[0013] The distillation process system for producing glycerol of the present utility model has been improved in the process systems of the distillation column and the drying and degassing tank, and can capture the escaped glycerol to the maximum extent, improve the yield of glycerol products and reduce the impact on the environment. Description of the Drawings
[0014] Figure 1 It is a schematic flow chart of the distillation process system for producing glycerol. Detailed Embodiments
[0015] In order to make the technical means, creative features, achieved purposes and effects of the present utility model easy to understand, the present utility model will be further described below with reference to specific embodiments.
[0016] As Figure 1 shown, it is a specific embodiment of the distillation process system for producing glycerol of the present utility model, which avoids the escape and loss of glycerol into the sewage, affecting the glycerol yield and the environment. Among them, the distillation process system includes a distillation column 3, a drying and degassing tank 1 and a glycerol capture device. The gas phase outlet of the distillation column 3 is communicated with the drying and degassing tank 1. The glycerol capture device includes a first glycerol trap 5 and a second glycerol trap 4. The top light component outlet of the distillation column 3 is connected to the first glycerol trap 5 to capture the glycerol escaping from the top light components of the distillation column 3. The water vapor outlet of the drying and degassing tank 1 is connected to a vacuum pumping device through the second glycerol trap 4 to capture the glycerol escaping from the water vapor outlet of the drying and degassing tank 1. The liquid phase generated by the drying and degassing tank 1 is communicated to the distillation column 3. The first glycerol trap 5 is a cooling water heat exchanger, and the second glycerol trap 4 is a temperature-controlled water heat exchanger. The liquid phase generated by the drying and degassing tank 1 is communicated to the distillation column 3 through a heater 2. The top light component outlet of the distillation column 3 is connected to the first glycerol trap 5 through a condenser 6. The material discharged from the distillation column 3 enters the decolorization column 9 through a material storage tank 8 and then reaches the finished product tank 10 in the tank area.
[0017] Generally, in the distillation column under 2 to 7 mbar, the crude glycerol is heated to about 160 °C; in the drying and degassing tank usually under 70 - 90 mbar, the crude glycerol is heated to 90 - 100 °C for dehydration inside the drying and degassing tank. The present utility model has improved the top of the distillation column to ensure that the glycerol escaping together with the light components is condensed; meanwhile, the drying and degassing tank has been improved to ensure that the water vapor is evacuated under a vacuum condition of 70 - 90 mbar, and at the same time, the glycerol mixed in the water vapor is condensed.
[0018] The described first glycerol trap 5 is provided with a cooling water inlet and a cooling water outlet. Through the cooling water inlet and the cooling water outlet, cooling water (such as chilled water or cold water) is introduced into the corresponding cooling water heat exchanger, and the temperature of the cooling chamber of the heat exchanger can be maintained at 20 to 30 °C. The low - molecular organic substances in the light component substances are still in the gas phase in the heat exchanger, and the glycerol in the light component substances can be condensed to trap the escaping glycerol. A steam jet pump 7 is arranged at the top of the described first glycerol trap 5 to eject the gas phase after the trapped glycerol.
[0019] The described second glycerol trap 4 is provided with a regulated - temperature water inlet and a regulated - temperature water outlet. Through the regulated - temperature water inlet and the regulated - temperature water outlet, the regulated - temperature water is introduced into the second glycerol trap 4. Among them, the regulated - temperature water can be about 50 °C. The water vapor discharged from the drying and degassing tank is still in the gas phase under the cooling of the regulated - temperature water and can continue to be evacuated in the gas phase by vacuum pumping. The glycerol in the water vapor can be condensed to trap the escaping glycerol.
[0020] Demisting meshes are arranged inside both the described first glycerol trap 5 and the second glycerol trap 4. Multiple layers of fins are arranged inside the described first glycerol trap 5. The demisting meshes and the fins can further trap the escaping glycerol to the maximum extent.
[0021] Based on the distillation process system of the present utility model, the glycerol content in the sewage is reduced from 2% to 0.6%, and it is expected that the glycerol yield can be increased by 0.3 to 0.5%; the COD of the sewage is reduced from 20000 + g / m 3 , to 6000 g / m 3 .
[0022] The distillation process system for producing glycerol of the present utility model has been improved in the process systems of the distillation column and the drying and degassing tank, which can trap the escaping glycerol to the maximum extent, improve the glycerol product yield and mitigate the impact on the environment.
[0023] In this specification, the present utility model has been described with reference to its specific embodiments. However, it is obvious that various modifications and transformations can still be made without departing from the spirit and scope of the present utility model. Therefore, the specification and the drawings should be regarded as illustrative rather than restrictive.
Claims
1. A distillation process system for producing glycerol, characterized in that, It includes a distillation column, a drying and degassing tank, and a glycerol trapping device. The gas-phase outlet of the distillation column is connected to the drying and degassing tank. The glycerol trapping device includes a first glycerol trap and a second glycerol trap. The top light-component outlet of the distillation column is connected to the first glycerol trap to trap glycerol escaping from the top light components of the distillation column. The water-vapor outlet of the drying and degassing tank is connected to a vacuum pumping device through the second glycerol trap to trap glycerol escaping from the water-vapor outlet of the drying and degassing tank. The liquid phase generated by the drying and degassing tank is communicated to the distillation column. The first glycerol trap is a cooling-water heat exchanger, and the second glycerol trap is a temperature-controlled water heat exchanger.
2. The distillation process system for producing glycerol according to claim 1, characterized in that, Demisting meshes are provided in both the first glycerol trap and the second glycerol trap.
3. The distillation process system for producing glycerol according to claim 1 or 2, characterized in that, Multiple layers of fins are provided in the first glycerol trap.
4. The distillation process system for producing glycerol according to claim 1, characterized in that, A cooling-water inlet and a cooling-water outlet are provided in the first glycerol trap.
5. The distillation process system for producing glycerol according to claim 1, characterized in that, A temperature-controlled water inlet and a temperature-controlled water outlet are provided in the second glycerol trap.
6. The distillation process system for producing glycerol according to claim 1, characterized in that, The top light-component outlet of the distillation column is connected to the first glycerol trap through a condenser.
7. The distillation process system for producing glycerol according to claim 1, characterized in that, A steam ejector pump is provided at the top of the first glycerol trap.
8. The distillation process system for producing glycerol according to claim 1, characterized in that, The liquid phase generated by the drying and degassing tank is connected to the distillation column through a heater.