Dichlorotoluene production system
By employing a heat medium circulation system in the 2,6-dichlorotoluene distillation column, utilizing the circulation of steam and condensate, the high energy consumption problem of the 2,6-dichlorotoluene distillation column was solved, and the energy consumption of the dichlorotoluene production system was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG ENG DESIGN
- Filing Date
- 2025-04-10
- Publication Date
- 2026-04-21
AI Technical Summary
In existing dichlorotoluene production systems, the 2,6-dichlorotoluene distillation column has high energy consumption, leading to an increase in overall energy consumption. This is especially true because 2,6-dichlorotoluene and 2,3-dichlorotoluene have similar boiling points and a high reflux ratio.
By employing a heat medium circulation system in the 2,6-dichlorotoluene distillation column, the steam from the second reboiler is used as a heat source and the condensate as a coolant. After condensation in the second condenser, the steam re-enters the reboiler, forming a cycle and reducing the energy consumption of the condenser and reboiler.
The energy consumption of the 2,6-dichlorotoluene distillation column was significantly reduced, thereby significantly reducing the energy consumption of the entire dichlorotoluene production system.
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Figure CN224141493U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of dichlorotoluene separation and purification, specifically to a dichlorotoluene production system. Background Technology
[0002] 2,3-Dichlorotoluene and 2,6-Dichlorotoluene are important fine chemicals used in the fine chemical industry, including pesticides, dyes, and pharmaceuticals. They can also be used as organic raw material intermediates in the preparation of other chemical products. Their production method involves using o-chlorotoluene as a raw material, which undergoes a chlorination reaction with chlorine gas under a catalyst to produce a crude mixture containing 2,3-dichlorotoluene, 2,6-dichlorotoluene, and a small amount of trichlorotoluene. This crude mixture is first separated to remove o-chlorotoluene using an o-chlorotoluene distillation column, then to remove 2,6-dichlorotoluene using a 2,6-dichlorotoluene distillation column, and finally to remove 2,3-dichlorotoluene using a 2,3-dichlorotoluene distillation column.
[0003] In the aforementioned technologies, the o-chlorotoluene distillation column, the 2,6-dichlorotoluene distillation column, and the 2,3-dichlorotoluene distillation column are all independently equipped with condensers and reboilers. The high-temperature latent heat released by the condensers of each distillation column is directly discharged to the environment through the cooling medium, while the reboiler requires additional steam heating. This independent operation mode results in a large energy consumption of the dichlorotoluene production system. In particular, the 2,6-dichlorotoluene distillation column has a high reflux ratio because the boiling points of 2,6-dichlorotoluene and 2,3-dichlorotoluene are close, resulting in a significantly higher energy consumption than the o-chlorotoluene and 2,3-dichlorotoluene distillation columns. Utility Model Content
[0004] This utility model aims to at least partially solve one of the technical problems in the related art.
[0005] Therefore, embodiments of this utility model propose a dichlorotoluene production system that can significantly reduce the energy consumption of the 2,6-dichlorotoluene distillation column, thereby reducing the energy consumption of the dichlorotoluene production system.
[0006] The dichlorotoluene production system of this utility model embodiment includes an o-chlorotoluene distillation column, a 2,6-dichlorotoluene distillation column, and a 2,3-dichlorotoluene distillation column connected in sequence. The o-chlorotoluene distillation column has an o-chlorotoluene outlet and a first inlet for crude dichlorotoluene mixture to enter. The 2,6-dichlorotoluene distillation column has a 2,6-dichlorotoluene outlet, and the 2,3-dichlorotoluene distillation column has a 2,3-dichlorotoluene outlet. The top of the 2,6-dichlorotoluene distillation column has a second condenser, and the bottom of the 2,6-dichlorotoluene distillation column has a second reboiler. The second condenser has a refrigerant inlet and a refrigerant outlet, and the second reboiler has a heat medium inlet and a heat medium outlet. The heat medium outlet of the second reboiler is connected to the refrigerant inlet of the second condenser, and the refrigerant outlet of the second condenser is connected to the heat medium inlet of the second reboiler.
[0007] In some embodiments, the dichlorotoluene production system further includes a cooler having a cooling channel, one end of which is connected to the hot medium outlet of the second reboiler, and the other end of which is connected to the refrigerant inlet of the second condenser.
[0008] In some embodiments, the dichlorotoluene production system further includes a compressor, and the refrigerant outlet of the second condenser is connected to the heat medium inlet of the second reboiler via the compressor.
[0009] In some embodiments, the heat medium inlet of the second reboiler is divided into two paths, one of which is connected to the refrigerant outlet of the second condenser, and the other is for the heating medium to enter.
[0010] The heat medium outlet of the second reboiler is divided into two paths, one of which is connected to the refrigerant inlet of the second condenser, and the other is used to discharge the heat medium.
[0011] In some embodiments, the o-chlorotoluene distillation column has a first condenser at the top and a first reboiler at the bottom.
[0012] In some embodiments, the top of the 2,3-dichlorotoluene distillation column has a third condenser, the third condenser having a refrigerant inlet and a refrigerant outlet, the refrigerant outlet of the third condenser being connected to the bottom of the o-chlorotoluene distillation column, the o-chlorotoluene distillation column having a first outlet, the first outlet being divided into two paths, one of which is connected to the 2,6-dichlorotoluene distillation column, and the other of which is connected to the refrigerant inlet of the third condenser.
[0013] In some embodiments, the o-chlorotoluene distillation column has an o-chlorotoluene outlet at the top, the 2,6-dichlorotoluene distillation column has a 2,6-dichlorotoluene outlet at the top, and the 2,3-dichlorotoluene distillation column has a 2,3-dichlorotoluene outlet at the top. At least one of the o-chlorotoluene outlet, the 2,6-dichlorotoluene outlet, and the 2,3-dichlorotoluene outlet is connected to a collection tank.
[0014] In some embodiments, the bottom of the 2,3-dichlorotoluene distillation column has a trichlorotoluene outlet, which is connected to a trichlorotoluene collection tank.
[0015] In some embodiments, the dichlorotoluene production system further includes a vacuum system, wherein the o-chlorotoluene distillation column, the 2,6-dichlorotoluene distillation column, and the 2,3-dichlorotoluene distillation column are all connected to the vacuum system.
[0016] The dichlorotoluene production system of this utility model connects the heat medium outlet of the second reboiler to the refrigerant inlet of the second condenser, and the refrigerant outlet of the second condenser to the heat medium inlet of the second reboiler. The heat medium of the second reboiler is steam, and the refrigerant of the second condenser is water. The steam enters through the heat medium inlet of the second reboiler to heat the bottom material of the 2,6-dichlorotoluene distillation column, and then turns into condensate which is discharged through the heat medium inlet of the second reboiler. The condensate then enters through the refrigerant inlet of the second condenser and is converted into steam in the second condenser, re-entering the heat medium inlet of the second reboiler as a heat source for the second reboiler. This creates a cycle between the second reboiler and the second condenser, which can significantly reduce the energy consumption of the condenser and reboiler of the 2,6-dichlorotoluene distillation column, thereby significantly reducing the energy consumption of the dichlorotoluene production system. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of a dichlorotoluene production system according to an embodiment of this utility model.
[0018] Figure label:
[0019] 100. Dichlorotoluene production system;
[0020] 1. o-chlorotoluene distillation column; 11. First inlet; 12. o-chlorotoluene outlet; 13. First outlet; 14. First condenser; 15. First reboiler;
[0021] 2. 2,6-Dichlorotoluene distillation column; 21. 2,6-Dichlorotoluene outlet; 22. Second condenser; 23. Second reboiler; 24. Second inlet; 25. Second outlet; 26. Cooler; 27. Compressor;
[0022] 3. 2,3-Dichlorotoluene distillation column; 31. 2,3-Dichlorotoluene outlet; 32. Third inlet; 33. Trichlorotoluene outlet; 34. Third condenser; 35. Third reboiler;
[0023] 41. First pump body; 42. Second pump body;
[0024] 5. Vacuum system. Detailed Implementation
[0025] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0026] like Figure 1 As shown, the dichlorotoluene production system 100 of this embodiment includes an o-chlorotoluene distillation column 1, a 2,6-dichlorotoluene distillation column 2, and a 2,3-dichlorotoluene distillation column 3 connected in sequence. The o-chlorotoluene distillation column 1 has an o-chlorotoluene outlet 12 and a first inlet 11 for crude product of the mixture to enter. The 2,6-dichlorotoluene distillation column 2 has a 2,6-dichlorotoluene outlet 21, and the 2,3-dichlorotoluene distillation column 3 has a 2,3-dichlorotoluene outlet 31. The top of the 2,6-dichlorotoluene distillation column 2 has a second condenser 22, and the bottom of the 2,6-dichlorotoluene distillation column 2 has a second reboiler 23. The second condenser 22 has a refrigerant inlet and a refrigerant outlet, and the second reboiler 23 has a heat medium inlet and a heat medium outlet. The heat medium outlet of the second reboiler 23 is connected to the refrigerant inlet of the second condenser 22, and the refrigerant outlet of the second condenser 22 is connected to the heat medium inlet of the second reboiler 23.
[0027] The production method of 2,3-dichlorotoluene and 2,6-dichlorotoluene uses o-chlorotoluene as raw material. O-chlorotoluene undergoes a chlorination reaction with chlorine gas under the catalysis of a catalyst to produce a crude dichlorotoluene mixture including 2,3-dichlorotoluene, 2,6-dichlorotoluene, and a small amount of trichlorotoluene. The dichlorotoluene production system 100 of this utility model embodiment is suitable for separating the crude dichlorotoluene mixture including 2,3-dichlorotoluene, 2,6-dichlorotoluene, and a small amount of trichlorotoluene. Specifically, the crude mixture is sequentially passed through o-chlorotoluene distillation column 1, 2,6-dichlorotoluene distillation column 2, and 2,3-dichlorotoluene distillation column 3. O-chlorotoluene is separated by o-chlorotoluene distillation column 1, 2,6-dichlorotoluene is separated by 2,6-dichlorotoluene distillation column 2, and 2,6-dichlorotoluene and trichlorotoluene are separated by 2,3-dichlorotoluene distillation column 3, thereby obtaining 2,3-dichlorotoluene and 2,6-dichlorotoluene products.
[0028] The dichlorotoluene production system 100 of this embodiment connects the heat medium outlet of the second reboiler 23 to the refrigerant inlet of the second condenser 22, and the refrigerant outlet of the second condenser 22 to the heat medium inlet of the second reboiler 23. The heat medium of the second reboiler 23 is steam, and the refrigerant of the second condenser 22 is water. The steam enters through the heat medium inlet of the second reboiler 23 to heat the bottom material of the 2,6-dichlorotoluene distillation column 2, and then becomes condensate, which is discharged through the heat medium inlet of the second reboiler 23 and enters through the refrigerant inlet of the second condenser 22 as the refrigerant. The condensate is converted into steam in the second condenser 22 and re-enters the heat medium inlet of the second reboiler 23 as a heat source for the second reboiler 23. This creates a cycle between the second reboiler 23 and the second condenser 22, which can significantly reduce the energy consumption of the condenser and reboiler of the 2,6-dichlorotoluene distillation column 2, and thus significantly reduce the energy consumption of the dichlorotoluene production system 100.
[0029] Specifically, such as Figure 1 As shown, the first inlet 11 is located in the middle of the o-chlorotoluene distillation column 1, and is used to feed a crude mixture including 2,3-dichlorotoluene, 2,6-dichlorotoluene and a small amount of trichlorotoluene. The top of the o-chlorotoluene distillation column 1 has an o-chlorotoluene outlet 12, through which the o-chlorotoluene obtained at the top of the column is discharged and further processed. The bottom of the o-chlorotoluene distillation column 1 has a first outlet 13, and the middle of the 2,6-dichlorotoluene distillation column 2 has a second inlet 24. The first outlet 13 and the second inlet 24 are connected by a first pump body 41. The bottom material after distillation in the o-chlorotoluene distillation column 1 enters the 2,6-dichlorotoluene distillation column 2 through the first outlet 13 and the second inlet 24 under the action of the first pump body 41 for further distillation.
[0030] The 2,6-dichlorotoluene distillation column 2 has a 2,6-dichlorotoluene outlet 21 at the top, through which the 2,6-dichlorotoluene obtained at the top of the column is discharged and further processed. The bottom of the 2,6-dichlorotoluene distillation column 2 has a second outlet 25, and the middle of the 2,3-dichlorotoluene distillation column 3 has a third inlet 32. The second outlet 25 and the third inlet 32 are connected by a second pump body 42. The bottom material after distillation in the 2,6-dichlorotoluene distillation column 2 enters the 2,3-dichlorotoluene distillation column 3 through the second outlet 25 and the third inlet 32 under the action of the second pump body 42 for further distillation.
[0031] The 2,3-dichlorotoluene distillation column 3 has a 2,3-dichlorotoluene outlet 31 at the top of the column, through which the 2,3-dichlorotoluene obtained at the top of the column is discharged and further processed; the bottom of the 2,3-dichlorotoluene distillation column 3 has a trichlorotoluene outlet 33, through which the material in the bottom of the 2,3-dichlorotoluene distillation column 3 is trichlorotoluene, which is discharged and further processed.
[0032] In some embodiments, the top of the o-chlorotoluene distillation column 1 has a first condenser 14, and the bottom of the o-chlorotoluene distillation column 1 has a first reboiler 15.
[0033] Specifically, such as Figure 1 As shown, the o-chlorotoluene distillation column 1 has a first condenser 14 at the top and a first reboiler 15 at the bottom. The first reboiler 15 is located outside the o-chlorotoluene distillation column 1 and can use steam to heat the o-chlorotoluene bottom material, ensuring that the bottom material is partially vaporized and forms an upward steam flow, thereby maintaining the continuity of the distillation process and the separation efficiency.
[0034] Similarly, the 2,3-dichlorotoluene distillation column 3 has a third condenser 34 at the top and a third reboiler 35 at the bottom. The third reboiler 35 is located outside the 2,3-dichlorotoluene distillation column 3 and can use steam to heat the bottom material of the 2,3-dichlorotoluene distillation column 3. The second reboiler 23 is located outside the 2,6-dichlorotoluene distillation column 2 and can use steam to heat the bottom material of the 2,6-dichlorotoluene distillation column 2.
[0035] In some embodiments, such as Figure 1 As shown, the dichlorotoluene production system 100 also includes a cooler 26, which has a cooling channel. One end of the cooling channel is connected to the hot medium outlet of the second reboiler 23, and the other end of the cooling channel is connected to the refrigerant inlet of the second condenser 22.
[0036] The refrigerant entering the second condenser 22 can be cooled and its temperature controlled by the cooler 26, so that the temperature of the condensate entering the second condenser 22 is appropriate.
[0037] Optionally, the refrigerant for the cooler 26 is water.
[0038] In some embodiments, such as Figure 1 As shown, the dichlorotoluene production system 100 also includes a compressor 27, and the refrigerant outlet of the second condenser 22 is connected to the heat medium inlet of the second reboiler 23 through the compressor 27.
[0039] Optionally, compressor 27 is a steam compressor.
[0040] Therefore, after the condensate is vaporized into steam in the second condenser 22, the compressor 27 can pressurize this part of the steam to be used as a heat source for the reboiler, thereby realizing steam circulation and reducing the energy consumption of the 2,6-dichlorotoluene distillation column 2.
[0041] In some embodiments, such as Figure 1 As shown, the heat medium inlet of the second reboiler 23 is divided into two paths, one of which is connected to the refrigerant outlet of the second condenser 22, and the other path is for the heating medium to enter; the heat medium outlet of the second reboiler 23 is divided into two paths, one of which is connected to the refrigerant inlet of the second condenser 22, and the other path is for the heating medium to exit.
[0042] With the above settings, part of the condensate discharged from the heat medium outlet of the second reboiler 23 is used for circulation between the second condenser 22 and the second reboiler 23, and the other part is discharged; at the same time, fresh steam can be added to the second reboiler 23 through the heat medium inlet to adjust the load of the second reboiler 23 and ensure the normal operation of the second reboiler 23.
[0043] In some embodiments, such as Figure 1 As shown, the third condenser 34 at the top of the 2,3-dichlorotoluene distillation column 3 also has a refrigerant inlet and a refrigerant outlet. The refrigerant outlet of the third condenser 34 is connected to the bottom of the o-chlorotoluene distillation column 1. The o-chlorotoluene distillation column 1 has a first outlet 13, which is divided into two paths. One path is connected to the 2,6-dichlorotoluene distillation column 2, and the other path is connected to the refrigerant inlet of the third condenser 34.
[0044] The load of the first reboiler 15 of the o-chlorotoluene distillation column 1 and the load of the third condenser 34 of the 2,3-dichlorotoluene distillation column 3 are relatively close, and their temperatures are also small. By setting up the above, the third condenser 34 and the first reboiler 15 are coupled, that is, a portion of the material in the bottom of the o-chlorotoluene distillation column 1 is used as the refrigerant for the third condenser 34, saving the load on the third condenser 34. At the same time, the temperature of the bottom material after heat exchange increases, which can save the load on the first reboiler 15, thereby reducing the energy consumption of the third condenser 34 of the 2,3-dichlorotoluene distillation column 3 and the first reboiler 15 of the o-chlorotoluene distillation column 1.
[0045] In some embodiments, such as Figure 1 As shown, the top of the o-chlorotoluene distillation column 1 has an o-chlorotoluene outlet 12, the top of the 2,6-dichlorotoluene distillation column 2 has a 2,6-dichlorotoluene outlet 21, and the top of the 2,3-dichlorotoluene distillation column 3 has a 2,3-dichlorotoluene outlet 31. At least one of the o-chlorotoluene outlet 12, the 2,6-dichlorotoluene outlet 21, and the 2,3-dichlorotoluene outlet 31 is connected to a collection tank.
[0046] Optionally, the o-chlorotoluene outlet 12 is connected to an o-chlorotoluene collection tank, the 2,6-dichlorotoluene outlet 21 is connected to a 2,6-dichlorotoluene collection tank, and the 2,3-dichlorotoluene outlet 31 is connected to a 2,3-dichlorotoluene collection tank. The o-chlorotoluene collection tank, the 2,6-dichlorotoluene collection tank, and the 2,3-dichlorotoluene collection tank all form the aforementioned collection tanks.
[0047] Therefore, the o-chlorotoluene product produced at the top of the o-chlorotoluene distillation column 1 can be stored in the o-chlorotoluene collection tank through the o-chlorotoluene outlet 12; the 2,6-dichlorotoluene product produced at the top of the 2,6-dichlorotoluene distillation column 2 can be stored in the 2,6-dichlorotoluene collection tank through the 2,6-dichlorotoluene outlet 21; and the 2,3-dichlorotoluene product produced at the top of the 2,3-dichlorotoluene distillation column 3 can be stored in the 2,3-dichlorotoluene collection tank through the 2,3-dichlorotoluene outlet 31.
[0048] In some embodiments, such as Figure 1 As shown, the bottom of the 2,3-dichlorotoluene distillation column 3 has a trichlorotoluene outlet 33, which is connected to a trichlorotoluene collection tank.
[0049] Therefore, the trichlorotoluene product from the bottom of the 2,3-dichlorotoluene tower can be stored in a trichlorotoluene collection tank.
[0050] In some embodiments, such as Figure 1 As shown, the dichlorotoluene production system 100 also includes a vacuum system 5, and the o-chlorotoluene distillation column 1, 2,6-dichlorotoluene distillation column 2 and 2,3-dichlorotoluene distillation column 3 are all connected to the vacuum system 5.
[0051] The vacuum system 5 can be used to adjust the pressure inside the o-chlorotoluene distillation column 1, 2,6-dichlorotoluene distillation column 2, and 2,3-dichlorotoluene distillation column 3 to ensure their normal operation.
[0052] As an example, the working process of the dichlorotoluene production system 100 of this utility model embodiment is as follows: The crude mixture generated by the chlorination reaction of o-chlorotoluene (the weight fraction of the crude mixture is: o-chlorotoluene 35%, 2,6-dichlorotoluene 40%, 2,3-dichlorotoluene 40%, trichlorotoluene 35%) is added to the o-chlorotoluene distillation column 1 at a feeding rate of 100 kg / h. The top temperature of the o-chlorotoluene distillation column 1 is controlled at 65°C and the bottom operating temperature is controlled at 135°C. The o-chlorotoluene product obtained from the top of the o-chlorotoluene distillation column 1 is sent to the o-chlorotoluene collection tank. Part of the bottom material of the o-chlorotoluene distillation column 1 is sent to the condenser of the 2,3-dichlorotoluene distillation column 3 for heat exchange through the first pump body 41, and the other part of the bottom material is pumped into the 2,6-dichlorotoluene distillation column 2. After stable operation, the energy consumption of circulating water in the first condenser 14 at the top of the o-chlorotoluene distillation column 1 is 6.04 kW, and the energy consumption of fresh steam in the first reboiler 15 at the bottom of the column is 1.42 kW.
[0053] In the 2,6-dichlorotoluene distillation column 2, the top temperature is controlled at 100℃ and the bottom operating temperature at 139℃. Heat pump technology is employed in the 2,6-dichlorotoluene distillation column 2. Specifically, the second condenser 22 at the top of the column uses the steam condensate from the second reboiler 23 at the bottom for condensation. The condensate from the second reboiler 23 is first cooled to 90℃ by a cooler 26 and then sent to the second condenser 22 at the top as a refrigerant. The vaporized steam from the condensate in the second condenser 22 is pressurized to 0.4MPa by a compressor 27 and then sent to the second reboiler 23 to heat the bottom material. The load on the reboiler is adjusted by adding fresh steam. The 2,6-dichlorotoluene product obtained from the top of the 2,6-dichlorotoluene distillation column 2 is sent to a 2,6-dichlorotoluene collection tank, and the bottom material is sent to the 2,3-dichlorotoluene distillation column 3 via a second pump 42. The circulating water energy consumption of the cooler 26 is 7.8kw, and the electric power of the compressor 27 is 13kw.
[0054] In the 2,3-dichlorotoluene distillation column 3, the top temperature is controlled at 148℃, and the bottom operating temperature is 182℃. The third condenser 34 at the top of the 2,3-dichlorotoluene distillation column 3 uses the bottom material from the o-chlorotoluene distillation column 1 for condensation. The third reboiler 35 at the bottom of the 2,3-dichlorotoluene distillation column 3 is heated by steam. The 2,3-dichlorotoluene obtained from the top is sent to a 2,3-dichlorotoluene collection tank, and the bottom material is pumped to a trichlorotoluene collection tank. After stable operation, the steam energy consumption of the reboiler at the bottom of the 2,3-dichlorotoluene distillation column 3 is 6.61 kW.
[0055] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0057] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0058] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0059] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A dichlorotoluene production system, characterized by, The device includes an o-chlorotoluene distillation column, a 2,6-dichlorotoluene distillation column, and a 2,3-dichlorotoluene distillation column connected in sequence. The o-chlorotoluene distillation column has an o-chlorotoluene outlet and a first inlet for crude dichlorotoluene mixture to enter. The 2,6-dichlorotoluene distillation column has a 2,6-dichlorotoluene outlet, and the 2,3-dichlorotoluene distillation column has a 2,3-dichlorotoluene outlet. The 2,6-dichlorotoluene distillation column has a second condenser at the top and a second reboiler at the bottom. The second condenser has a refrigerant inlet and a refrigerant outlet, and the second reboiler has a heat medium inlet and a heat medium outlet. The heat medium outlet of the second reboiler is connected to the refrigerant inlet of the second condenser, and the refrigerant outlet of the second condenser is connected to the heat medium inlet of the second reboiler.
2. The dichlorotoluene production system according to claim 1, characterized by, The dichlorotoluene production system also includes a cooler having a cooling channel. One end of the cooling channel is connected to the hot medium outlet of the second reboiler, and the other end of the cooling channel is connected to the refrigerant inlet of the second condenser.
3. The dichlorotoluene production system according to claim 1, characterized by, The dichlorotoluene production system also includes a compressor, and the refrigerant outlet of the second condenser is connected to the heat medium inlet of the second reboiler through the compressor.
4. The dichlorotoluene production system according to claim 1, characterized by, The heat medium inlet of the second reboiler is divided into two paths, one of which is connected to the refrigerant outlet of the second condenser, and the other is for the heating medium to enter. The heat medium outlet of the second reboiler is divided into two paths, one of which is connected to the refrigerant inlet of the second condenser, and the other is used to discharge the heat medium.
5. The dichlorotoluene production system according to claim 1, characterized by, The o-chlorotoluene distillation column has a first condenser at the top and a first reboiler at the bottom.
6. The dichlorotoluene production system according to any one of claims 1 to 5, characterized by, The 2,3-dichlorotoluene distillation column has a third condenser at the top, which has a refrigerant inlet and a refrigerant outlet. The refrigerant outlet of the third condenser is connected to the bottom of the o-chlorotoluene distillation column. The o-chlorotoluene distillation column has a first outlet, which is divided into two paths, one of which is connected to the 2,6-dichlorotoluene distillation column and the other is connected to the refrigerant inlet of the third condenser.
7. The dichlorotoluene production system according to any one of claims 1 to 5, characterized by, The o-chlorotoluene distillation column has an o-chlorotoluene outlet at the top, the 2,6-dichlorotoluene distillation column has a 2,6-dichlorotoluene outlet at the top, and the 2,3-dichlorotoluene distillation column has a 2,3-dichlorotoluene outlet at the top. At least one of the o-chlorotoluene outlet, the 2,6-dichlorotoluene outlet, and the 2,3-dichlorotoluene outlet is connected to a collection tank.
8. The dichlorotoluene production system according to claim 7, characterized by, The bottom of the 2,3-dichlorotoluene distillation column has a trichlorotoluene outlet, which is connected to a trichlorotoluene collection tank.
9. The dichlorotoluene production system according to claim 1, characterized by, The dichlorotoluene production system also includes a vacuum system, and the o-chlorotoluene distillation column, the 2,6-dichlorotoluene distillation column, and the 2,3-dichlorotoluene distillation column are all connected to the vacuum system.