Heat-integrated methanol rectification energy-saving device
By adding a pressurized distillation column before the atmospheric distillation column, and using the steam heat source and preheater of the pressurized distillation column to heat the raw material, the problem of high energy consumption in the methanol distillation process was solved, and a significant reduction in energy consumption was achieved.
Patent Information
- Application Number
- CN202520207947.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-10
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-02-10
AI Technical Summary
The existing methanol distillation process is energy-intensive and consumes a lot of steam, so a more efficient and energy-saving device is needed.
A pressurized distillation column is added before the atmospheric distillation column. The steam at the top of the pressurized distillation column is used as the heat source for the reboiler of the atmospheric column to recover and utilize heat. The feed is then heated through a preheater to achieve thermal integration and reduce system energy consumption.
By using thermal integration technology, the energy consumption of the methanol distillation process has been significantly reduced, achieving high efficiency and energy saving.
Smart Images
Figure CN223774333U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of methanol distillation, specifically relating to a thermally integrated methanol distillation energy-saving device. Background Technology
[0002] Methanol is an important chemical raw material and one of the basic organic raw materials, used in many fields such as fine chemicals, polymers, pesticides, pharmaceuticals, and energy, and holds a very important position in the international chemical market. Currently, the main production method for methanol is the low-pressure synthesis of CO, H2, and CO2, producing crude methanol. In addition to water, crude methanol contains impurities such as ethanol, formic acid, methyl acetate, dimethyl ether, and higher alcohols. To remove these impurities, continuous distillation is required to purify the crude methanol into refined methanol that meets quality requirements.
[0003] The current methanol distillation process is as follows: crude methanol from the pre-distillation column is added to the main distillation column, refined methanol is collected from the top of the column, fusel oil is collected from the lower part of the column, and the bottom liquid is sent to the saturation column. The reflux ratio of the entire column is 2.5, and the steam consumption is approximately 95 t / h, of which 46 t / h comes from low-pressure steam from the waste heat boiler, and the remainder comes from the low-pressure steam main. Methanol distillation consumes a relatively large amount of energy. Utility Model Content
[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a methanol distillation device that is highly efficient, energy-saving, and reduces steam consumption.
[0005] To address the aforementioned problems, this utility model provides a thermally integrated methanol distillation energy-saving device, comprising an atmospheric distillation column and a pressurized distillation column located at the front end of the atmospheric distillation column. The top of the pressurized distillation column is provided with a first outlet, a steam outlet, and a first reflux port, while the top of the atmospheric distillation column is provided with a second outlet. The steam outlet of the pressurized distillation column is connected to the reboiler of the atmospheric distillation column via a pipeline, and the condensate outlet of the atmospheric distillation column is connected to the first reflux port of the pressurized distillation column.
[0006] The bottom of the pressurized distillation column is provided with a first liquid outlet, which is connected to the feed inlet of the atmospheric distillation column. The feed inlet of the pressurized distillation column is connected to the raw material input end through a feed pipe. A first preheater is connected to the feed pipe, and a first outlet is connected to the first preheater.
[0007] This utility model relates to a thermally integrated methanol distillation energy-saving device. A pressurized distillation column is added upstream of the atmospheric distillation column. Crude methanol from the pre-distillation column is fed into the pressurized distillation column via a feed pipe. After operation, a first portion of refined methanol is collected from the first outlet at the top of the pressurized distillation column, and crude methanol is discharged from the first outlet at the bottom of the pressurized distillation column as bottom liquid, which is then fed into the atmospheric distillation column. Simultaneously, methanol vapor is output from the vapor outlet at the top of the pressurized distillation column as a heat source for the reboiler of the atmospheric distillation column. This allows for the recovery and utilization of heat from the atmospheric distillation column. The reboiler condenses methanol vapor and discharges it from the condensate outlet of the atmospheric distillation column. The vapor then flows back into the pressurized distillation column through the first reflux port. A second portion of refined methanol is collected from the second outlet at the top of the atmospheric distillation column. Furthermore, the feed inlet of the pressurized distillation column is connected to the raw material input end via a feed pipe. A first preheater is connected to the feed pipe, connecting the first outlet to the first preheater. The first portion of refined methanol collected from the first outlet is sent to the first preheater, thereby heating the raw material passing through the first preheater. This achieves thermal integration and saves system energy consumption.
[0008] In some embodiments, the bottom of the pressurized distillation column is further provided with a second liquid outlet, and a second preheater is connected to the feed pipe. The second preheater is located at the rear end of the first preheater along the feed direction. The second liquid outlet and the second preheater are connected through a secondary preheating pipe, which is sequentially connected to a gas-liquid separator and a pressurized column intermediate reboiler. The pressurized column intermediate reboiler is connected to the middle side wall of the pressurized distillation column. Thus, the first portion of refined methanol collected from the first outlet is used to heat the feed material passing through the first preheater, completing the primary preheating of the feed material. Then, a portion of crude methanol is discharged through the second liquid outlet, passing sequentially through the gas-liquid separator and the pressurized column intermediate reboiler. The gas separated by the gas-liquid separator enters the pressurized column intermediate reboiler through the secondary preheating pipe for heating, and then is sent to the second preheater, thus continuing to preheat the feed material, completing the secondary preheating of the feed material, and saving system energy consumption.
[0009] In some embodiments, a reboiler is connected between the second liquid outlet and the gas-liquid separator, and the reboiler is connected to the bottom of the pressurized distillation column; the bottom of the gas-liquid separator is provided with a waste liquid outlet for discharging waste liquid, and the second preheater is provided with a conversion gas interface. Thus, the conversion gas discharged from the second preheater is sent to incineration through the conversion gas interface.
[0010] In some embodiments, the inlet of the pressurized tower reboiler is connected to the converted gas from the boiler feedwater preheater. Thus, the pressurized tower reboiler uses the converted gas from the boiler feedwater preheater as a heat source for heating.
[0011] In some embodiments, a first reflux tank and a first reflux pump are provided between the condensate outlet of the atmospheric distillation column reboiler and the first reflux port of the pressurized distillation column. Thus, the methanol vapor is condensed and refluxed back into the pressurized distillation column by the first reflux tank and the first reflux pump.
[0012] In some embodiments, the first and second outlets are connected to a refined methanol storage tank, and a second reflux tank and a second reflux pump are connected between the second outlet and the refined methanol storage tank. Thus, refined methanol collected from the second outlet at the top of the atmospheric distillation column can be mixed with refined methanol collected from the first outlet and then transported to the refined methanol storage tank.
[0013] In some embodiments, the top of the atmospheric distillation column is provided with a second reflux port, and a second reflux pump is connected to the second reflux port. Thus, through the second reflux tank and the second reflux pump, a portion of liquid methanol can be recovered from the atmospheric distillation column via the second reflux port.
[0014] In some embodiments, the feed inlet of the pressurized distillation column is located on the middle side wall of the pressurized distillation column, and the feed inlet of the atmospheric distillation column is located on the middle side wall of the atmospheric distillation column.
[0015] In some embodiments, the bottom of the atmospheric distillation column is provided with a drain outlet for discharging the distillation bottom water. Thus, the distillation bottom water inside the atmospheric distillation column is discharged through the drain outlet.
[0016] In some embodiments, the atmospheric distillation column has a side stream with a fusel oil outlet. This allows fusel oil to be discharged through the fusel oil outlet. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of a thermally integrated methanol distillation energy-saving device according to one embodiment of the present invention.
[0018] In the picture:
[0019] 00. Raw material input end; 01. Feed pipe; 10. Pressurized distillation column; 11. First outlet; 12. Steam outlet; 13. First reflux port; 14. First liquid outlet; 15. First feed inlet; 16. Second liquid outlet; 20. Atmospheric distillation column; 21. Second outlet; 22. Second feed inlet; 23. Second reflux port; 24. Drain outlet; 25. Fusel oil outlet; 30. Atmospheric column reboiler; 31. Condensate outlet; 4 0. First preheater; 50. Second preheater; 51. Secondary preheating pipe; 52. Converted gas interface; 60. Gas-liquid separator; 61. Waste liquid outlet; 70. Intermediate reboiler of pressurized tower; 80. Reboiler at the bottom of pressurized tower; 90. Converted gas from boiler feedwater preheater; 100. First reflux tank; 110. First reflux pump; 120. Second reflux tank; 130. Second reflux pump; A. First part refined methanol; B. Second part refined methanol. Detailed Implementation
[0020] The present invention will now be described in further detail with reference to the accompanying drawings.
[0021] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship 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 do not 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. Furthermore, the terms "first," "second," etc., 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. The terms "comprising," "including," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.
[0022] Figure 1 The diagram schematically illustrates a thermally integrated methanol distillation energy-saving device according to one embodiment of the present invention. For example... Figure 1 As shown, the apparatus includes an atmospheric distillation column 20 and a pressurized distillation column 10 located at the front end of the atmospheric distillation column 20. The top of the pressurized distillation column 10 is provided with a first outlet 11, a steam outlet 12, and a first reflux port 13. The top of the atmospheric distillation column 20 is provided with a second outlet 21. An atmospheric reboiler 30 is connected to the reboiler of the atmospheric distillation column 20 via a pipe. The shell side of the atmospheric reboiler is connected to the steam outlet 12 of the pressurized distillation column 10 via a pipe. The condensate outlet 31 of the atmospheric distillation column reboiler 30 is connected to the first reflux port 13 of the pressurized distillation column 10. The bottom of the pressurized distillation column 10 has a first liquid outlet 14, which is connected to the feed inlet (first feed inlet 15) of the atmospheric distillation column 20. The feed inlet (second feed inlet 22) of the pressurized distillation column 10 is connected to the raw material input end 00 via a feed pipe 01. A first preheater 40 is connected to the feed pipe 01, and a first outlet 11 is connected to the first preheater 40. Preferably, the first feed inlet 15 of the pressurized distillation column 10 is located on the middle side wall of the pressurized distillation column 10, and the second feed inlet 22 of the atmospheric distillation column 20 is located on the middle side wall of the atmospheric distillation column 20.
[0023] Based on the above-described thermally integrated methanol distillation energy-saving device, a pressurized distillation column 10 is added at the front end of the atmospheric distillation column 20. Crude methanol from the pre-distillation column is fed into the first feed inlet 15 of the pressurized distillation column 10 through the feed pipe 01. After the pressurized distillation column 10 operates, a first portion of refined methanol A is collected from the first outlet 11 at the top of the pressurized distillation column 10, and crude methanol is output from the first liquid outlet 14 at the bottom of the pressurized distillation column 10 as the bottom liquid, which is then fed into the second feed inlet 22 of the atmospheric distillation column 20. Simultaneously, methanol vapor is output from the vapor outlet 12 at the top of the pressurized distillation column 10 as the heat source for the atmospheric reboiler 30. This allows for the recovery and utilization of heat after reboiling in the atmospheric distillation column. The reboiler 30 condenses methanol vapor and discharges it from the condensate outlet 31 of the atmospheric distillation column reboiler 30. The vapor then flows back into the pressurized distillation column 10 from the first reflux port 13. The second portion of refined methanol B is collected from the second outlet 21 at the top of the atmospheric distillation column 20. Furthermore, the first feed port 15 of the pressurized distillation column 10 is connected to the raw material input end 00 through the feed pipe 01. A first preheater 40 is connected to the feed pipe 01, and the first outlet 11 is connected to the first preheater 40. The first portion of refined methanol collected from the first outlet 11 is sent to the first preheater 40, thereby heating the raw material passing through the first preheater 40. This achieves thermal integration and saves system energy consumption.
[0024] In a preferred embodiment, the bottom of the pressurized distillation column 10 is also provided with a second liquid outlet 16, and a second preheater 50 is connected to the feed pipe 01. The second preheater 50 is located at the rear end of the first preheater 40 along the feed direction. The second liquid outlet 16 and the second preheater 50 are connected through a secondary preheating pipe 51. A gas-liquid separator 60 and a pressurized column intermediate reboiler 70 are connected in sequence to the secondary preheating pipe 51. The pressurized column intermediate reboiler 70 is connected to the middle side wall of the pressurized distillation column 10. Thus, the first portion of refined methanol A extracted from the first outlet 11 is used to heat the raw material passing through the first preheater 40, completing the primary preheating of the raw material; then, a portion of crude methanol is discharged through the second outlet 16, passing sequentially through the gas-liquid separator 60 and the intermediate reboiler 70 of the pressurized tower, so that the gas separated by the gas-liquid separator 60 enters the intermediate reboiler 70 of the pressurized tower through the secondary preheating pipe 51 for heating, and then is sent to the second preheater 50, thus continuing to preheat the raw material, completing the secondary preheating of the raw material, and saving system energy consumption.
[0025] A reboiler 80 for the pressurized column is connected between the second liquid outlet 16 and the gas-liquid separator 60. The reboiler 80 is connected to the bottom of the pressurized distillation column 10. The bottom of the gas-liquid separator 60 is provided with a waste liquid outlet 61 for discharging waste liquid, and the second preheater 50 is provided with a conversion gas inlet 52. Thus, the conversion gas discharged from the second preheater 50 is sent to incineration through the conversion gas inlet 52. Furthermore, the inlet of the reboiler 80 for the pressurized column is connected to the conversion gas 90 from the boiler feedwater preheater. Thus, the reboiler 80 for the pressurized column uses the conversion gas 90 from the boiler feedwater preheater as a heat source for heating.
[0026] In this embodiment, a first reflux tank 100 and a first reflux pump 110 are provided between the condensate outlet 31 of the atmospheric distillation column reboiler 30 and the first reflux port 13 of the pressurized distillation column 10. Thus, the methanol vapor is condensed and refluxed back into the pressurized distillation column 10 via the first reflux tank 100 and the first reflux pump 110. Preferably, the first outlet 11 and the second outlet 21 are connected to a refined methanol storage tank, and a second reflux tank 120 and a second reflux pump 130 are connected between the second outlet 21 and the refined methanol storage tank. Therefore, refined methanol collected from the second outlet 21 at the top of the atmospheric distillation column 20 can be mixed with refined methanol collected from the first outlet 11 and then transported to the refined methanol storage tank.
[0027] Furthermore, the top of the atmospheric distillation column 20 is provided with a second reflux port 23, and a second reflux pump 130 is connected to the second reflux port 23. Thus, through the second reflux tank 120 and the second reflux pump 130, a portion of liquid refined methanol can be recovered from the atmospheric distillation column 20 through the second reflux port 23.
[0028] In a more specific embodiment, the bottom end of the atmospheric distillation column 20 is provided with a drain outlet 24 for discharging the distillation bottom water. Thus, the distillation bottom water inside the atmospheric distillation column 20 is discharged through the drain outlet 24. A fusel oil outlet 25 is provided on the side of the atmospheric distillation column 20. Thus, fusel oil can be discharged through the fusel oil outlet 25.
[0029] This utility model's thermally integrated methanol distillation energy-saving device adds a pressurized distillation column at the front end of an atmospheric distillation column. A first portion of refined methanol is collected from the first outlet at the top of the pressurized distillation column, and methanol vapor is output from the vapor outlet at the top of the pressurized distillation column as a heat source for the reboiler of the atmospheric column. This allows for heat recovery and utilization. The methanol vapor is condensed in the atmospheric column reboiler and discharged from the condensate outlet of the atmospheric column reboiler, then flows back into the pressurized distillation column. A second portion of refined methanol is collected from the second outlet at the top of the atmospheric distillation column. Simultaneously, the collected first portion of refined methanol is sent to the first preheater to heat the raw material passing through the first preheater. This achieves thermal integration and saves system energy consumption.
[0030] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this utility model.
Claims
1. A thermally integrated methanol distillation energy-saving device, comprising an atmospheric pressure distillation column, characterized in that, It also includes a pressurized distillation column located at the front end of the atmospheric distillation column. The top of the pressurized distillation column is provided with a first outlet, a steam outlet, and a first reflux port. The top of the atmospheric distillation column is provided with a second outlet. The steam outlet of the pressurized distillation column is connected to the bottom of the atmospheric distillation column via a pipeline to an atmospheric reboiler. The condensate outlet of the atmospheric reboiler is connected to the first reflux port of the pressurized distillation column. The pressurized distillation column is provided with a first liquid outlet at the bottom, which is connected to the feed inlet of the atmospheric distillation column. The feed inlet of the pressurized distillation column is connected to the raw material input end through a feed pipe. A first preheater is connected to the feed pipe, and the first outlet is connected to the first preheater.
2. The thermally integrated methanol distillation energy-saving device according to claim 1, characterized in that, The bottom of the pressurized distillation column is also provided with a second liquid outlet, and a second preheater is connected to the feed pipe. The second preheater is located at the rear end of the first preheater along the feed direction. The second liquid outlet is connected to the second preheater through a secondary preheating pipe. A gas-liquid separator and a pressurized column intermediate reboiler are connected in sequence to the secondary preheating pipe. The pressurized column intermediate reboiler is connected to the middle side wall of the pressurized distillation column.
3. The thermally integrated methanol distillation energy-saving device according to claim 2, characterized in that, A reboiler is connected between the second liquid outlet and the gas-liquid separator, and the reboiler is connected to the bottom of the pressurized distillation column; the bottom of the gas-liquid separator is provided with a waste liquid outlet for discharging waste liquid, and the second preheater is provided with a conversion gas interface.
4. The thermally integrated methanol distillation energy-saving device according to claim 3, characterized in that, The gas inlet of the reboiler in the pressurized tower is connected to the conversion gas of the boiler feedwater preheater.
5. The thermally integrated methanol distillation energy-saving device according to claim 1, characterized in that, A first reflux tank and a first reflux pump are provided between the condensate outlet of the atmospheric distillation column reboiler and the first reflux port of the pressurized distillation column.
6. The thermally integrated methanol distillation energy-saving device according to claim 1, characterized in that, The first and second extraction outlets are connected to the refined methanol storage tank, and a second reflux tank and a second reflux pump are connected between the second extraction outlet and the refined methanol storage tank.
7. The thermally integrated methanol distillation energy-saving device according to claim 6, characterized in that, The top of the atmospheric distillation column is provided with a second reflux port, and the second reflux pump is connected to the second reflux port.
8. The energy-saving thermal integrated methanol distillation device according to any one of claims 1-6, characterized in that, The feed inlet of the pressurized distillation column is located on the middle side wall of the pressurized distillation column, and the feed inlet of the atmospheric distillation column is located on the middle side wall of the atmospheric distillation column.
9. The thermally integrated methanol distillation energy-saving device according to any one of claims 1-6, characterized in that, The bottom of the atmospheric distillation column is provided with a drain outlet for discharging the bottom water of the distillation process.
10. The thermally integrated methanol distillation energy-saving device according to claim 1, characterized in that, The atmospheric distillation column has a fusel oil outlet on its side.