Rectification device for treating naphthalene-containing methanol
By designing a distillation device for processing naphthalene-containing methanol, and utilizing the combined structure of an azeotropic tower, a distillation tower and a thermal regeneration tower, the problem of naphthalene treatment in the low-temperature methanol washing section is solved, and efficient separation of methanol and water is achieved. The stable treatment of naphthalene ensures the normal operation of the process section and the saving of steam.
Patent Information
- Application Number
- CN202420524460.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-18
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-03-18
AI Technical Summary
During the production process of the low-temperature methanol washing section, the mixture of methanol and water produced contains impurities naphthalene, which is difficult to effectively deal with in the prior art, affecting the normal operation of the section.
Design a distillation device including a coexistence tower, distillation tower and thermal regeneration tower. The mixture is transported to the distilled tower through the supply tube to provide heat using the re -boiling device to control the pressure and temperature in the tower to ensure that to ensure that 不 Keep liquid, does not produce gas or condense into solids to avoid blocking the tower.
Effectively separate methanol, water, and 萘, improved the concentration of methanol and refined distillation, saved the steam use of the thermal regeneration tower, and ensured the normal operation of the working segment.
Smart Images
Figure CN222384193U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of coal chemical production, and specifically relates to a rectification device for processing naphthalene-containing methanol. Background Art
[0002] During the production process of the low-temperature methanol washing section, a mixture of methanol and water will be produced, which needs to be treated by a distillation device. In the actual production process, the azeotropic bottom product is transported to the middle of the distillation tower by a feed pump. This part of the methanol contains naphthalene as an impurity. If the naphthalene is not properly treated, it will affect the normal operation of the entire section.
[0003] For this reason, a distillation device for processing naphthalene-containing methanol is urgently needed. Utility Model Content
[0004] In view of the above-mentioned defects in the prior art, the utility model provides a distillation device for treating naphthalene-containing methanol, comprising an azeotropic tower, a distillation tower and a thermal regeneration tower, the azeotropic tower is connected to the middle part of the distillation tower through a feed pipe, and a feed pump and a first flow control valve are arranged on the feed pipe, the top of the distillation tower is connected to the thermal regeneration tower through a steam pipeline, a plurality of layers of floating valve trays are arranged inside the distillation tower, a reboiler is connected to the bottom of the distillation tower, the reboiler is used to provide heat for the distillation tower, the thermal regeneration tower is connected to the top of the distillation tower through a reflux pipe, and a second flow control valve is arranged on the reflux pipe.
[0005] Optionally, 30-40 layers of floating valve trays are arranged inside the distillation tower.
[0006] Specifically, the distillation tower is mainly used to separate methanol from methanol water for use in the thermal regeneration tower stripping.
[0007] Optionally, the internal pressure of the distillation tower is controlled at 0.15-0.2 MPa, the top temperature of the distillation tower is controlled at 85-90°C, and the bottom temperature of the distillation tower is controlled at 130-135°C.
[0008] Specifically, since the melting point of naphthalene is 80-82°C and the boiling point is 218°C, the boiling point of methanol is 65°C, and the boiling point of water is 100°C, under this condition, after naphthalene enters the distillation tower from the feed position, it will flow downward with the liquid phase, always remain in liquid state, and will not produce gas. At the same time, it can also prevent naphthalene from condensing into a solid below the freezing point and causing tower plate blockage, thereby ensuring the continuous and stable operation of the entire device.
[0009] Optionally, a wastewater pipeline is connected to the bottom of the distillation tower, and a wastewater pump is provided on the wastewater pipeline.
[0010] Specifically, the alcohol-containing wastewater leaving the bottom of the distillation tower is cooled in the feed heater of the azeotropic tower through countercurrent heat exchange with the materials entering the azeotropic tower, and then sent out of the boundary area to the biochemical treatment device for purification of the wastewater.
[0011] Optionally, the distillation device for treating naphthalene-containing methanol is further provided with a sodium hydroxide storage tank, which is connected to the reboiler via a liquid supply pipe, and an alkali liquid injection pump is provided on the liquid supply pipe.
[0012] Specifically, in order to reduce the blockage of the tube side of the reboiler of the distillation tower, the sodium hydroxide solution in the sodium hydroxide storage tank can be sprayed to the bottom of the distillation tower through the alkali solution injection pump; in addition, the sodium hydroxide storage tank is also connected to the desalted water pipeline, low-pressure steam pipeline, condensate pipeline and alkali solution tank area.
[0013] The utility model also includes other components that enable a rectification device for treating naphthalene-containing methanol to be used normally, which are all conventional technical means in the art. In addition, the devices or components not limited in the utility model all adopt conventional technical means in the art.
[0014] The working principle of the utility model is that the bottom product of the azeotropic tower is a mixture of methanol and water, which also contains naphthalene as an impurity. The mixture of methanol and water enters the distillation tower through a feed pipe. Under the action of heat provided by a reboiler, the pressure in the distillation tower is controlled at 0.16MPa, the temperature at the top of the tower is controlled at 90°C, and the temperature at the bottom of the tower is controlled at 131°C. Under this working condition, naphthalene will flow downward with the liquid phase and always remain in a liquid state without generating gas. At the same time, it can also prevent naphthalene from condensing into a solid below the freezing point and causing blockage of the tower plate. Methanol and water are first in the liquid phase. It flows to the bottom of the tower, becomes gaseous and rises to the top of the tower. Water condenses into liquid while methanol remains gaseous. At this time, water can be separated from methanol. Then liquid water flows downward and returns to the bottom of the tower, while gaseous methanol enters the thermal regeneration tower along the steam pipe to save steam. At the same time, a small amount of lean methanol liquid is extracted from the lean oil pump and returned to the distillation tower after passing through the lean / rich methanol heat exchanger as reflux liquid. The alcohol-containing wastewater leaving the bottom of the distillation tower is cooled in the feed heater of the azeotropic tower by countercurrent heat exchange with the materials to the azeotropic tower, and then sent out of the boundary area to the biochemical treatment device. In order to reduce the blockage of the pipe side of the reboiler of the distillation tower, the sodium hydroxide solution is sprayed to the bottom of the distillation tower. The sodium hydroxide solution comes from the sodium hydroxide storage tank and is sprayed by the alkali liquid injection pump.
[0015] The beneficial effect of the utility model is that it can distill the methanol-water mixture produced in the low-temperature methanol washing section, and can separate the water while separating the impurity naphthalene, thereby increasing the methanol concentration and the distillation accuracy, which can not only save steam for the thermal regeneration tower, but also ensure the normal operation of the entire section. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0018] In the figure: 1. azeotropic tower, 2. distillation tower, 3. thermal regeneration tower, 4. feed pipe, 5. feed pump, 6. first flow control valve, 7. steam pipeline, 8. float valve tray, 9. reboiler, 10. reflux pipe, 11. second flow control valve, 12. wastewater pipeline, 13. wastewater pump, 14. sodium hydroxide storage tank, 15. liquid supply pipe, 16. alkali solution injection pump. DETAILED DESCRIPTION
[0019] The present invention is described in detail below in conjunction with the drawings and specific embodiments in the embodiments of the present invention. The description here is only used to explain the present invention, but not to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent replacements, improvements, etc., should be included in the protection scope of the present invention.
[0020] Example
[0021] like Figure 1 As shown, the embodiment of the utility model provides a distillation device for treating naphthalene-containing methanol, including an azeotropic tower 1, a distillation tower 2 and a thermal regeneration tower 3, the azeotropic tower 1 is connected to the middle part of the distillation tower 2 through a feed pipe 4, and a feed pump 5 and a first flow control valve 6 are provided on the feed pipe 4, the top of the distillation tower 2 is connected to the thermal regeneration tower 3 through a steam pipe 7, and 40 layers of floating valve trays 8 are provided inside the distillation tower 2. The distillation tower 2 is mainly used to separate methanol from methanol water for gas stripping by the thermal regeneration tower 3. A reboiler 9 is connected to the bottom of the distillation tower 2, and the reboiler 9 is used to provide heat for the distillation tower 2. The thermal regeneration tower 3 is connected to the top of the distillation tower 2 through a reflux pipe 10, and a second flow control valve 11 is provided on the reflux pipe 10.
[0022] In addition, the internal pressure of the distillation tower 2 is controlled at 0.16MPa, the top temperature of the distillation tower 2 is controlled at 90°C, and the bottom temperature of the distillation tower 2 is controlled at 131°C. Since the melting point of naphthalene is 80-82°C, the boiling point is 218°C, the boiling point of methanol is 65°C, and the boiling point of water is 100°C, under this condition, after naphthalene enters the distillation tower 2 from the feed position, it will flow downward with the liquid phase, always remain in a liquid state, and will not produce gas. At the same time, it can also prevent naphthalene from condensing into a solid below the freezing point and causing tower plate blockage, thereby ensuring the continuous and stable operation of the entire device.
[0023] The bottom of the distillation tower 2 is connected to a wastewater pipeline 12, and a wastewater pump 13 is provided on the wastewater pipeline 12. The alcohol-containing wastewater leaving the bottom of the distillation tower 2 is cooled by countercurrent heat exchange with the material to the azeotropic tower 1 in the feed heater of the azeotropic tower 1, and then sent out of the boundary area to the biochemical treatment device for purification of the wastewater.
[0024] The distillation device for treating naphthalene-containing methanol is also provided with a sodium hydroxide storage tank 14, which is connected to the reboiler 9 through a liquid supply pipe 15, and an alkali liquid injection pump 16 is provided on the liquid supply pipe 15. In order to reduce the blockage of the tube side of the reboiler 9 of the distillation tower 2, the sodium hydroxide solution in the sodium hydroxide storage tank 14 can be sprayed to the bottom of the distillation tower 2 through the alkali liquid injection pump 16.
[0025] The working principle of the utility model is that the bottom product of the azeotropic tower 1 is a mixture of methanol and water, which also contains naphthalene as an impurity. The mixture of methanol and water enters the distillation tower 2 through the feed pipe 4. Under the action of heat provided by the reboiler 9, the pressure in the distillation tower 2 is controlled at 0.16MPa, the top temperature is controlled at 90°C, and the bottom temperature is controlled at 131°C. Under this working condition, naphthalene will flow downward with the liquid phase and always remain in a liquid state without generating gas. At the same time, it can also prevent naphthalene from condensing into a solid below the freezing point and causing blockage of the tower plate. Methanol and water are first in the liquid phase. It flows to the bottom of the tower, becomes gaseous and then rises to the top of the tower. Water condenses into liquid while methanol remains gaseous. At this time, water can be separated from methanol. Then liquid water flows downward and returns to the bottom of the tower, while gaseous methanol enters the thermal regeneration tower 3 along the steam pipe 7 to save steam. At the same time, a small amount of lean methanol liquid is extracted from the lean oil pump and then passed through the lean / rich methanol heat exchanger to flow back to the distillation tower 2 as reflux liquid; the alcohol-containing wastewater leaving the bottom of the distillation tower 2 is cooled in the feed heater of the azeotropic tower 1 by countercurrent heat exchange with the materials to the azeotropic tower 1, and then sent out of the boundary area to the biochemical treatment device. In order to reduce the blockage of the pipe side of the reboiler 9 of the distillation tower 2, the sodium hydroxide solution is sprayed to the bottom of the distillation tower 2. The sodium hydroxide solution comes from the sodium hydroxide storage tank 14 and is sprayed by the alkali liquid injection pump 16.
[0026] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.
Claims
1. A distillation device for treating naphthalene-containing methanol, comprising an azeotropic tower, a distillation tower and a thermal regeneration tower, characterized in that: The azeotropic tower is connected to the middle part of the distillation tower through a feed pipe, and a feed pump and a first flow control valve are arranged on the feed pipe. The top of the distillation tower is connected to the thermal regeneration tower through a steam pipe. Several layers of floating valve trays are arranged inside the distillation tower. A reboiler is arranged at the bottom of the distillation tower, and the reboiler is used to provide heat for the distillation tower. The thermal regeneration tower is connected to the top of the distillation tower through a reflux pipe, and a second flow control valve is arranged on the reflux pipe.
2. The distillation device for processing naphthalene-containing methanol according to claim 1, characterized in that: The interior of the distillation tower is provided with 30-40 layers of floating valve trays.
3. The distillation device for processing naphthalene-containing methanol according to claim 1, characterized in that: The internal pressure of the distillation tower is controlled at 0.15-0.2MPa, the top temperature of the distillation tower is controlled at 85-90°C, and the bottom temperature of the distillation tower is controlled at 130-135°C.
4. The distillation device for treating naphthalene-containing methanol according to claim 1, characterized in that: The bottom of the distillation tower is connected with a wastewater pipeline, and a wastewater pump is arranged on the wastewater pipeline.
5. The distillation device for treating naphthalene-containing methanol according to claim 1, characterized in that: A sodium hydroxide storage tank is also provided, which is connected to the reboiler through a liquid supply pipe, and an alkali solution injection pump is provided on the liquid supply pipe.