Azeotrope distillation system
By using a preheater, trays, and reflux system in the azeotropic distillation system, combined with deep separation in the second distillation column, the problem of low separation efficiency in azeotropic distillation technology is solved, enabling the production of high-purity products and efficient energy utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 宁夏福瑞硅烷材料有限公司
- Filing Date
- 2025-05-31
- Publication Date
- 2026-06-05
AI Technical Summary
Existing azeotropic distillation technology has low separation efficiency when separating azeotropic mixtures, making it difficult to achieve high purity requirements, which leads to impurities in the synthesis of methoxysilane compounds.
An azeotropic distillation system including a preheater, trays, reflux system, and reboiler is adopted. The material is preheated by the preheater, the gas-liquid contact area is increased by the trays, the gas-liquid balance in the column is regulated by the reflux, and deep separation is carried out by the second distillation column to achieve efficient separation of components and recovery of azeotropic agent.
It improves the separation accuracy and purity of azeotropes, enhances mass and heat transfer processes, enables secondary energy utilization, and significantly improves separation efficiency and product purity.
Smart Images
Figure CN224321037U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of distillation and separation technology, specifically to an azeotropic distillation system. Background Technology
[0002] Azeotropic distillation is an important separation technique that separates components based on the difference in their boiling points at different temperatures. When two or more components have very similar boiling points, traditional distillation methods struggle to separate them effectively. Azeotropic distillation, however, adds a third substance called an azeotropic agent to the mixture to alter its boiling point, allowing components with similar boiling points to be separated at different temperatures. It is widely used in various fields such as chemical, petroleum, food, and pharmaceutical industries.
[0003] Methoxysilane compounds react with water and hydrolyze to form alcohols and silanols, making it impossible to obtain the target product. Therefore, it is necessary to completely remove moisture from the reactants. Existing azeotropic distillation technology has low separation efficiency when separating azeotropic mixtures, making it difficult to achieve the high product purity requirements, resulting in the introduction of other impurities in the synthesis of methoxysilane compounds. Summary of the Invention
[0004] This invention provides an azeotropic distillation system to solve the problem of low purity caused by low separation efficiency in existing azeotropic distillation technology.
[0005] To solve the above problems, this utility model provides an azeotropic distillation system, comprising: a first distillation column, a preheater connected to the liquid inlet located in the middle of the first distillation column, a heat exchanger connected to the exhaust port located at the top of the first distillation column, a first condenser connected to one end of the heat exchanger, a first stratification tank connected to the liquid outlet of the first condenser, a reflux liquid inlet located on the upper side wall of the first distillation column connected to one end of the first stratification tank, and a first reboiler circulatedly connected to the bottom of the first distillation column;
[0006] Through the above scheme, the preheater preheats the material entering the distillation column. The preheated material can reach the appropriate distillation temperature more quickly after entering the column, which speeds up the distillation process. At the same time, the addition of reflux liquid can regulate the gas-liquid balance in the column, increase the mass transfer driving force in the column, further optimize the distillation process, improve distillation efficiency, and help to achieve more efficient separation of azeotropes.
[0007] According to one embodiment of the present invention, the first distillation column is provided with a plurality of trays. Through the above scheme, the trays provide sufficient contact surface and space for the gas and liquid phases. When the rising gas passes through the liquid layer on the tray, it comes into full contact with the liquid, so that the light components in the gas phase continuously transfer to the liquid phase, and the heavy components in the liquid phase continuously transfer to the gas phase, which greatly increases the mass transfer efficiency, thereby improving the separation accuracy of each component of the azeotrope and making the final product have higher purity.
[0008] According to one embodiment of the present invention, the above-mentioned tray is provided with a receiving tray, an overflow weir, and a sieve plate. With the above scheme, the sieve plate has a large number of evenly distributed small holes. The gas rises through the small holes in the form of small bubbles and comes into full contact with the liquid received by the receiving tray. The dispersed bubbles increase the contact area between the gas and liquid phases, which greatly promotes the mass transfer process, allowing the lighter components in the gas phase to enter the liquid phase more quickly, and the heavier components in the liquid phase to enter the gas phase more effectively, thereby improving the separation efficiency of each component of the azeotrope.
[0009] According to one embodiment of the present invention, one end of the first reboiler is connected to the bottom of the first distillation column through a circulating liquid pipe, and the other end of the first reboiler is connected to the side wall of the first distillation column through a return liquid pipe. Through the above scheme, the circulation method enables the liquid at the bottom of the column to continuously obtain heat, generate more rising vapor, maintain the temperature at the boiling point of the azeotrope, and allow more rising vapor to fully contact the descending liquid in the column, thereby enhancing the heat and mass transfer process between the gas and liquid, accelerating the separation rate of each component in the azeotrope, and improving the distillation efficiency.
[0010] According to one embodiment of the present invention, a hydraulic pump is provided on both the circulating liquid pipe and the reflux liquid pipe. Through the above scheme, the hydraulic pump can accurately control the flow rate of the circulating liquid and the reflux liquid by adjusting the speed and valve opening. The appropriate reflux liquid flow rate can adjust the reflux ratio in the tower, affect the concentration gradient of each component in the tower, and enable the light and heavy components to be separated more effectively in the tower, thereby improving the purity and yield of the product.
[0011] According to one embodiment of this utility model, the high-temperature outlet of the heat exchanger is connected to the heat source inlet of the preheater via a high-temperature pipe, and the low-temperature outlet of the preheater is connected to the cold source inlet of the heat exchanger via a low-temperature pipe. Through this scheme, the fluid discharged from the high-temperature outlet of the heat exchanger still carries a large amount of waste heat, which is transported to the heat source inlet of the preheater via the high-temperature pipe. This allows the recovery of heat that might otherwise be wasted. The preheater uses this recovered heat to preheat the materials entering the system, achieving secondary energy utilization and significantly improving the energy recovery rate of the entire system.
[0012] According to one embodiment of the present invention, the bottom of the first layering tank is provided with a drain port. Through the above scheme, after the liquid mixture is allowed to stand and separate in the layering tank, the bottom drain port can accurately separate the phase with a lower content of the target component, reduce the contamination of the target product by impurities, and help to obtain a high-purity product.
[0013] According to one embodiment of this utility model, the above-mentioned drain port is connected to a second distillation column via a pipe. The bottom of the second distillation column is provided with a second reboiler in circulation. The bottom end of the second distillation column is connected to the reflux inlet of the first distillation column via a pipe. The gas outlet at the top of the second distillation column is connected to a second condenser. The liquid outlet of the second condenser is connected to a second separator. One end of the second separator is connected to the upper side wall of the second distillation column via a reflux pipe. The second separator is also provided with a drain port. Through the distillation action of the second distillation column, components that are not completely separated in the first distillation column can be deeply separated. These components are difficult to completely separate in the first distillation column. After the second distillation column, the relative volatility difference between these components can be increased, achieving more effective separation and obtaining high-purity single components. Ultimately, the azeotropic agent can be recovered and utilized.
[0014] The technical advantages of this application are as follows:
[0015] This application provides an azeotropic distillation system that preheats the material entering the distillation column using a preheater. The preheated material reaches the appropriate distillation temperature more quickly upon entering the column, accelerating the distillation process. Simultaneously, the addition of reflux liquid regulates the gas-liquid balance within the column, increasing the mass transfer driving force and further optimizing the distillation process, thus improving distillation efficiency and facilitating more efficient separation of azeotropes. A second distillation column is also provided to further separate components not completely separated in the first column, obtaining high-purity single components, ultimately achieving the recovery and utilization of the azeotropic agent. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of an azeotropic distillation system provided by this utility model.
[0017] Explanation of reference numerals in the attached figures:
[0018] 1. First distillation column; 101. Separated liquid outlet; 102. Reflux liquid inlet; 103. Exhaust port; 104. Liquid inlet; 105. Return liquid pipe; 106. Circulating liquid pipe; 107. Tray; 2. First reboiler; 3. Preheater; 301. Heat source inlet; 302. Low temperature side outlet; 4. Heat exchanger; 401. High temperature side outlet; 402. Cold source inlet; 5. First condenser; 6. First separator; 601. Drain port; 7. Hydraulic pump; 8. Second distillation column; 9. Second reboiler; 10. Second condenser; 11. Second separator. Detailed Implementation
[0019] The following will be combined with the appendix Figure 1 The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples and should not be used to limit the scope of protection of this application.
[0020] Reference Figure 1 This utility model provides an azeotropic distillation system, comprising: a first distillation column 1, a preheater 3 connected to an inlet 104 located in the middle of the first distillation column 1, a heat exchanger 4 connected to an exhaust port 103 located at the top of the first distillation column 1, a first condenser 5 connected to one end of the heat exchanger 4, a first stratification tank 6 connected to the outlet end of the first condenser 5, a reflux inlet 102 located on the upper side wall of the first distillation column 1 connected to one end of the first stratification tank 6, and a first reboiler 2 circulatedly connected to the bottom of the first distillation column 1;
[0021] Through the above scheme, the preheater 3 preheats the material entering the distillation column. The preheated material can reach the appropriate distillation temperature more quickly after entering the column, which speeds up the distillation process. At the same time, the addition of reflux liquid can regulate the gas-liquid balance in the column, increase the mass transfer driving force in the column, further optimize the distillation process, improve the distillation efficiency, and help to achieve more efficient separation of azeotropes.
[0022] The first distillation column 1 is equipped with several trays 107. Through the above scheme, the trays 107 provide sufficient contact surface and space for the gas and liquid phases. When the rising gas passes through the liquid layer on the tray 107, it comes into full contact with the liquid, which causes the light components in the gas phase to continuously transfer to the liquid phase and the heavy components in the liquid phase to continuously transfer to the gas phase, which greatly increases the mass transfer efficiency and improves the separation accuracy of each component of the azeotrope, resulting in a higher purity of the final product.
[0023] The tray 107 is equipped with a receiving tray, an overflow weir, and a sieve plate. With the above design, the sieve plate has numerous evenly distributed small holes. Gas rises through the small holes in the form of small bubbles, making full contact with the liquid received by the receiving tray. The dispersed bubbles increase the contact area between the gas and liquid phases, greatly promoting the mass transfer process. This allows the lighter components in the gas phase to enter the liquid phase more quickly, and the heavier components in the liquid phase to enter the gas phase more effectively, thereby improving the separation efficiency of each component of the azeotrope.
[0024] One end of the first reboiler 2 is connected to the bottom of the first distillation column 1 through the circulating liquid pipe 106, and the other end of the first reboiler 2 is connected to the side wall of the first distillation column 1 through the return liquid pipe 105. Through the above scheme, the circulation method allows the liquid at the bottom of the column to continuously obtain heat, generate more rising vapor, maintain the temperature at the bottom of the column at the boiling point of the azeotrope, and allow more rising vapor to fully contact the descending liquid in the column, thereby enhancing the heat and mass transfer process between the gas and liquid, accelerating the separation rate of each component in the azeotrope, and improving the distillation efficiency.
[0025] Hydraulic pumps 7 are installed on both the circulating liquid pipe 106 and the reflux liquid pipe. Through the above scheme, the hydraulic pumps 7 can accurately control the flow rates of the circulating liquid and reflux liquid by adjusting the speed and valve opening. The appropriate reflux liquid flow rate can adjust the reflux ratio in the tower, affect the concentration gradient of each component in the tower, and enable the light and heavy components to be separated more effectively in the tower, thereby improving the purity and yield of the product.
[0026] The high-temperature side outlet 401 of the heat exchanger 4 is connected to the heat source inlet 301 of the preheater 3 through a high-temperature pipe, and the low-temperature side outlet 302 of the preheater 3 is connected to the cold source inlet 402 of the heat exchanger 4 through a low-temperature pipe. With the above scheme, the fluid discharged from the high-temperature side outlet 401 of the heat exchanger 4 still carries a large amount of waste heat, which is transported to the heat source inlet 301 of the preheater 3 through a high-temperature pipe, so that this part of the heat that might otherwise be wasted can be recovered. The preheater 3 uses this recovered heat to preheat the materials entering the system, realizing the secondary utilization of energy and significantly improving the energy recovery rate of the entire system.
[0027] The first stratification tank 6 is provided with a drain port 601 at the bottom. Through the above scheme, after the liquid mixture is allowed to stand and separate in the stratification tank, the drain port 601 at the bottom can accurately separate the phase with a lower content of the target component, reduce the contamination of the target product by impurities, and help to obtain a high-purity product.
[0028] The aforementioned drain outlet 601 is connected to the second distillation column 8 via a pipeline. The bottom of the second distillation column 8 is equipped with a second reboiler 9 in circulation. The bottom end of the second distillation column 8 is connected to the reflux inlet 102 of the first distillation column 1 via a pipeline. The gas outlet at the top of the second distillation column 8 is connected to the second condenser 10. The liquid outlet of the second condenser 10 is connected to the second stratification tank 11. One end of the second stratification tank 11 is connected to the upper side wall of the second distillation column 8 via a reflux pipeline. The second stratification tank 11 is also equipped with a drain outlet. Through the distillation action of the second distillation column 8, components that are not completely separated in the first distillation column 1 can be deeply separated. These components are difficult to completely separate in the first distillation column 1. After the second distillation in the second distillation column 8, the relative volatility difference between these components can be increased, achieving more effective separation and obtaining high-purity single components. Ultimately, the azeotropic agent can be recovered and utilized.
[0029] Working principle:
[0030] The water-containing reactant mixture is pumped into the preheater 3, where it is heated to 60-70°C. The preheated mixture enters the first distillation column 1 through the inlet 104 and flows to the bottom of the column through the tray 107. After being heated to 80-90°C in the first reboiler 2, it is recycled back into the first distillation column 1, where mass and heat transfer occur between the liquid and vapor on the tray. Materials with a density and boiling point slightly lower than water form a minimum temperature azeotrope with water under high temperature. The high-temperature steam is discharged from the exhaust port 103 at the top of the column and enters the heat exchanger 4. The gas-liquid mixture after heat exchange enters the condenser and is condensed into liquid. The condensed liquid enters the separator. The materials with a density and boiling point slightly lower than water have a lower density than water. The upper layer in the separator is the materials with a density and boiling point slightly lower than water, and the lower layer is water. The upper material phase is used as reflux liquid. Most of it is sent back to the top of the distillation column to maintain the liquid load and azeotropic agent concentration in the column. A small part is sent to the second distillation column 8 with water. The components with a boiling point higher than water accumulate at the bottom of the first distillation column 1. The separation liquid outlet 101 at the bottom of the first distillation column 1 is connected to a reaction vessel for product synthesis.
[0031] The aqueous phase and part of the organic phase separated from the separatory tank enter the second distillation column 8. Utilizing the boiling point difference between the reactants and water, the mixture is heated by the second reboiler 9. Temperature control is maintained, and benzene and water are separated using tray 107. The liquid reactants are then pumped from the bottom of the second distillation column 8 through a hydraulic pump 7 into the reflux inlet 102, entering the first distillation column 1 where they undergo mass and heat transfer with steam on the trays. The steam exits from the top outlet of the second distillation column 8 into the second condenser 10, where it is condensed and then enters the second separatory tank 11. The upper layer of the second separatory tank 11 contains only a small amount of reactants, and this upper reactant phase continues to reflux back to the second distillation column 8 for further separation.
[0032] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. An azeotropic distillation system, characterized in that, include: A first distillation column (1), a preheater (3) connected to the liquid inlet (104) located in the middle of the first distillation column (1), a heat exchanger (4) connected to the exhaust port (103) located at the top of the first distillation column (1), a first condenser (5) connected to one end of the heat exchanger (4), a first layer tank (6) connected to the liquid outlet of the first condenser (5), a reflux liquid inlet (102) located on the upper side wall of the first distillation column (1) connected to one end of the first layer tank (6), and a first reboiler (2) connected to the bottom of the first distillation column (1) in a circulating manner.
2. The azeotropic distillation system according to claim 1, characterized in that, The first distillation column (1) is equipped with several trays (107).
3. The azeotropic distillation system according to claim 2, characterized in that, The tray (107) is equipped with a liquid receiving tray, an overflow weir, and a sieve plate.
4. The azeotropic distillation system according to claim 1, characterized in that, One end of the first reboiler (2) is connected to the bottom of the first distillation column (1) through a circulating liquid pipe (106), and the other end of the first reboiler (2) is connected to the side wall of the first distillation column (1) through a return liquid pipe (105).
5. The azeotropic distillation system according to claim 4, characterized in that, Hydraulic pumps (7) are installed on both the circulating liquid pipe (106) and the return liquid pipe.
6. The azeotropic distillation system according to claim 1, characterized in that, The high-temperature side outlet (401) of the heat exchanger (4) is connected to the heat source inlet (301) of the preheater (3) through a high-temperature pipe, and the low-temperature side outlet (302) of the preheater (3) is connected to the cold source inlet (402) of the heat exchanger (4) through a low-temperature pipe.
7. The azeotropic distillation system according to claim 1, characterized in that, The first layered tank (6) is provided with a drain port (601) at the bottom.
8. The azeotropic distillation system according to claim 7, characterized in that, The drain port (601) is connected to the second distillation column (8) through a pipe. The bottom of the second distillation column (8) is provided with a second reboiler (9) in circulation. The bottom end of the second distillation column (8) is connected to the reflux inlet of the first distillation column (1) through a pipe. The gas outlet at the top of the second distillation column (8) is connected to the second condenser (10). The liquid outlet of the second condenser (10) is connected to the second layer tank (11). One end of the second layer tank (11) is connected to the upper side wall of the second distillation column (8) through a reflux pipe. The second layer tank (11) is also provided with a drain port.