Steam utilization device in methanol synthesis
By combining flash tanks and deaerators, the heat and water resources in the black water generated during methanol synthesis are recovered and reused, solving the problem of black water waste and achieving efficient resource utilization.
Patent Information
- Application Number
- CN202520400960.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-03-10
AI Technical Summary
During methanol synthesis, the heat and water resources in the black water are not effectively recovered, resulting in waste.
By setting up a flash tank, black water is flashed to generate steam, which is then used to heat the ash water in the deaerator. The flashed black water is used to preheat the ash water, while the heat-exchanged black water is recycled back to the scrubbing tower for reuse.
It effectively recovers heat and water resources from black water, avoiding waste and improving resource utilization.
Smart Images
Figure CN223840342U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy utilization technology, and in particular to a steam utilization device in methanol synthesis. Background Technology
[0002] Coal-to-methanol production mainly includes high-pressure, medium-pressure, and low-pressure methods. Among these, the low-pressure method has become the mainstream method due to its low equipment requirements, high product purity, cost savings, and high capacity. The production process involves: preparing a 62% coal-water slurry from raw coal and reacting it with oxygen in a gasifier at 6.5 MPaG and 1347℃ to produce crude raw gas. After preliminary washing, the crude raw gas is sent to a shift converter. In the shift converter, the raw gas reacts under the catalysis of a catalyst to synthesize methanol. During this synthesis reaction, due to solid slag discharge, the crude synthesis gas produced by the gasification reaction contains a certain amount of impurities such as tar, phenol, and ammonia. A large amount of black water is generated during the gas washing process. Because the reaction is carried out under high temperature and high pressure conditions, this black water also has a high temperature and contains a large amount of heat energy. If it is not recovered, it will result in a waste of water resources and heat. Utility Model Content
[0003] This application provides a steam utilization device for methanol synthesis, which is used to recover water resources and heat from the black water generated in methanol production, thereby avoiding the problem of water and heat waste.
[0004] This application provides a steam utilization device for methanol synthesis, comprising a scrubbing tower, a flash tank, and a deaerator connected in series.
[0005] The flash tank is also connected to the tube-side inlet of the heat exchanger, and the tube-side outlet of the heat exchanger is also connected to the scrubbing tower.
[0006] The shell-side inlet of the heat exchanger is connected to the water supply pipeline, and the shell-side outlet of the heat exchanger is connected to the deaerator.
[0007] Optionally, a filter is installed between the tube-side outlet of the heat exchanger and the scrubbing tower, and the filter is also connected to the boiler.
[0008] Optionally, the flash tank is connected to a heat tracing device via a valve;
[0009] The deaerator is also connected to the steam line.
[0010] Optionally, the flash tank includes a tank body and a filter screen horizontally disposed within the tank body;
[0011] The top of the tank is equipped with a steam outlet and a vent valve, and the bottom is equipped with a first drain outlet;
[0012] The tank is also equipped with a spray device, which is located between the filter screen and the first drain port and is connected to the washing tower.
[0013] The steam outlet is connected to the deaerator, and the first drain outlet is connected to the tube-side inlet of the heat exchanger.
[0014] Optionally, the spraying device includes a horizontally arranged connecting pipe, the output end of which is connected to the sprayer;
[0015] The connecting tube has a tapering structure from the input end to the output end.
[0016] Optionally, the deaerator includes a deaerator body, the top of which is connected to the steam-water separator;
[0017] An aeration pipe is installed at the bottom of the deaerator body, and the aeration pipe is connected to the flash tank.
[0018] The inner top of the deaerator body is suspended by a connecting beam and a liquid distribution plate is connected. Multiple liquid distribution holes are opened at the bottom of the liquid distribution plate, and multiple umbrella-shaped liquid distribution plates are vertically arranged on the upper surface of the liquid distribution plate. Each liquid distribution plate corresponds to the liquid inlet pipe opened at the top of the deaerator body.
[0019] A second drain port is provided at the bottom of the deaerator body.
[0020] Optionally, the steam-water separator is horizontally equipped with multiple layers of demisters, and the aperture of the multiple layers of demisters decreases sequentially along the steam flow direction;
[0021] A pressure relief valve is connected to the top of the steam-water separator.
[0022] This application provides a steam utilization device for methanol synthesis. A flash evaporator is used to generate steam from high-temperature black water. This steam is then fed into a deaerator to heat and deoxygenate the grey water entering the deaerator. The flash-evaporated black water is then fed into a heat exchanger to preheat the grey water entering the deaerator. Simultaneously, the heat-exchanged black water is recycled to a scrubbing tower for reuse. This device, through the combined use of the above equipment, recovers the heat from the black water generated during methanol production by flash evaporation to generate steam. The residual heat from flash evaporation is used to preheat grey water, and the heat-exchanged black water is returned to the scrubbing tower for reuse. This effectively reuses the black water and its heat, effectively avoiding the waste of water and heat resources. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1This is a schematic diagram of a steam utilization device in methanol synthesis provided in one embodiment of this application;
[0025] Figure 2 This is a schematic diagram of a steam utilization device in methanol synthesis provided in another embodiment of this application;
[0026] Figure 3 A schematic diagram of a steam utilization device in methanol synthesis provided in another embodiment of this application;
[0027] Figure 4 This is a schematic diagram of the structure of a flash tank provided in one embodiment of this application;
[0028] Figure 5 This is a schematic diagram of the structure of a deaerator provided in one embodiment of this application.
[0029] Explanation of reference numerals in the attached figures:
[0030] 1. Scrubber; 2. Flash tank; 3. Deaerator; 4. Heat exchanger; 5. Filter; 6. Boiler; 7. Heat tracing device; 10. Water supply pipeline; 20. Steam pipeline; 21. Tank body; 22. Filter screen; 23. Spray device; 31. Deaerator body; 32. Steam-water separator; 33. Aeration pipe; 34. Liquid distribution plate; 35. Liquid inlet pipe; 201. Steam outlet; 202. Vent valve; 203. First drain port; 231. Connecting pipe; 232. Sprayer; 301. Second drain port; 321. Demister; 322. Pressure relief valve; 341. Liquid distribution plate. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.
[0032] like Figure 1 As shown, this application provides a steam utilization device for methanol synthesis, including a scrubbing tower 1, a flash tank 2 and a deaerator 3 connected in series.
[0033] The flash tank 2 is also connected to the tube-side inlet of the heat exchanger 4, and the tube-side outlet of the heat exchanger 4 is also connected to the scrubbing tower 1.
[0034] The shell-side inlet of heat exchanger 4 is connected to the water supply pipeline 10, and the shell-side outlet of heat exchanger 4 is connected to the deaerator 3.
[0035] In methanol synthesis, the synthesis gas output from the synthesis reactor is washed away in a scrubbing tower 1 to remove sulfides and other impurities. The washed-off carbon and other impurities mix with the wash water to form black water. During use, the black water (temperature approximately 180-220℃) discharged from the scrubbing tower 1 is fed into a flash tank 2 for flash evaporation. Some of the water in the black water flashes and forms steam due to the reduced pressure, while the unvaporized water falls to the bottom of the flash tank 2 and is discharged. The discharged black water still has a relatively high temperature (approximately 100℃) and is fed into the tube side of a heat exchanger 4 to preheat the grey water supplied to the deaerator 3 from the water supply line 10 for deoxygenation. The preheated black water is then fed into the scrubbing tower 1 as washing water, while the heated grey water is fed into the deaerator 3 for deoxygenation. Meanwhile, the steam output from the flash tank 2 enters the deaerator 3 to heat and deoxygenate the grey water fed into the deaerator 3.
[0036] This application provides a steam utilization device for methanol synthesis. A flash evaporator 2 is used to generate steam from high-temperature black water. This steam is then fed into a deaerator 3 to heat and deoxygenate the grey water entering the deaerator 3. The flash-evaporated black water is then fed into a heat exchanger 4 to preheat the grey water entering the deaerator 3. Simultaneously, the heat-exchanged black water is recycled to a scrubbing tower 1 for reuse. This device, through the combined use of the above equipment, recovers the heat from the black water generated during methanol production by flash evaporation to generate steam. Simultaneously, the residual heat from flash evaporation is used to preheat the grey water, and the heat-exchanged black water is returned to the scrubbing tower 1 for reuse. This effectively reuses the black water and its heat, effectively avoiding the waste of water and heat resources.
[0037] like Figure 2 As shown, optionally, a filter 5 is provided between the tube outlet of the heat exchanger 4 and the scrubbing tower 1, and the filter 5 is also connected to the boiler 6.
[0038] In this application, since the black water contains solid impurities such as carbon, it is necessary to filter it before use. During use, the black water output from heat exchanger 4 is filtered through filter 5 and then fed into scrubbing tower 1 as washing water. The solid impurities intercepted by filter 5 are fed into boiler 6 and co-fired with pulverized coal as fuel.
[0039] like Figure 3 As shown, optionally, the flash tank 2 is connected to the heat tracing device 7 via a valve;
[0040] The deaerator 3 is also connected to the steam line 20.
[0041] In this application, a portion of the steam output from the flash tank 2 enters the deaerator 3 to heat and deaerate the ash water entering the deaerator 3. The other portion is input into the heat tracing device 7 for use in sections requiring heat tracing. Simultaneously, to prevent insufficient steam production from the flash tank 2, a steam pipeline 20 is connected to the deaerator 3 to supplement the steam supply. Accordingly, valves are installed on the corresponding pipelines between the flash tank 2 and the heat tracing device 7, between the deaerator 3 and the steam pipeline 20, and between the flash tank 2 and the deaerator 3 to control the steam output direction.
[0042] like Figure 4 As shown, optionally, the flash tank 2 includes a tank body 21 and a filter screen 22 horizontally disposed inside the tank body 21;
[0043] The top of the tank body 21 is provided with a steam outlet 201 and a vent valve 202, and the bottom is provided with a first drain port 203;
[0044] The tank 21 is also equipped with a spray device 23, which is located between the filter screen 22 and the first drain port 203 and is connected to the washing tower 1.
[0045] Steam outlet 201 is connected to deaerator 3, and first drain outlet 203 is connected to tube inlet of heat exchanger 4.
[0046] In this application, a portion of the black water in tank 21 is flash-vaporized. Since solid impurities such as carbon contained in the black water are mixed into the steam, the generated steam is filtered out by filter 22 as it is discharged, trapping the solid impurities and some water mist, thereby increasing the dryness of the generated steam. The unvaporized water falls into the lower part of flash tank 2 and is then discharged from the first drain port 203.
[0047] like Figure 4 As shown, optionally, the spraying device 23 includes a horizontally arranged connecting pipe 231, the output end of which is connected to the sprayer 232;
[0048] The connecting tube 231 has a structure that tapers from the input end to the output end.
[0049] In this application, black water enters from the connecting pipe 231 of the flash tank 2 and is atomized by spraying through the sprayer 232. Some of the sprayed water undergoes flash evaporation to form steam due to the reduced pressure. Furthermore, due to the tapered structure of the connecting pipe 231, the flow rate output from the connecting pipe 231 increases, which is beneficial for its atomization when sprayed from the sprayer 232.
[0050] like Figure 5 As shown, optionally, the deaerator 3 includes a deaerator body 31, the top of which is connected to the steam-water separator 32.
[0051] An aeration pipe 33 is provided at the bottom of the deaerator body 31, and the aeration pipe 33 is connected to the flash tank 2.
[0052] The inner top of the deaerator body 31 is suspended by a connecting beam and a liquid distribution plate 34 is connected. The bottom of the liquid distribution plate 34 is provided with multiple liquid distribution holes. Multiple umbrella-shaped liquid distribution plates 341 are vertically arranged on the upper surface of the liquid distribution plate 34. Each liquid distribution plate 341 corresponds to the liquid inlet pipe 35 opened at the top of the deaerator body 31.
[0053] A second drain port 301 is provided at the bottom of the deaerator body 31.
[0054] In this application, the grey water, after heat exchange with black water in heat exchanger 4, is input into the deaerator 3 through the inlet pipe 35. As it falls, it lands on the umbrella-shaped distribution plate 341. Through the buffering and even distribution effect of the distribution plate 341, the grey water flow impacts and forms small droplets that fall onto the distribution plate 34, or forms a liquid film under the even distribution of the distribution plate 341 and falls onto the distribution plate 34, then falls as droplets through the distribution holes on the distribution plate 34. At the same time, steam output from flash tank 2 is input through aeration pipe 33 to aerate the grey water in deaerator 3. The rising steam comes into countercurrent contact with the falling grey water droplets, heating the grey water droplets and reducing the solubility of oxygen in the grey water, thereby removing oxygen from the grey water.
[0055] like Figure 5 As shown, optionally, a multi-layer demister 321 is horizontally arranged inside the steam-water separator 32, and the aperture of the multi-layer demister 321 decreases sequentially along the steam flow direction.
[0056] A pressure relief valve 322 is connected to the top of the steam-water separator 32.
[0057] The oxygen removed from the ash water rises with the steam and enters the steam-water separator 32 through the connection between the steam-water separator 32 and the deaerator body 31. Since the discharged steam also contains a small amount of water mist, a multi-layer demister 321 is installed in the steam-water separator 32 to intercept the water mist in the upward discharged steam and reduce the loss of ash water.
[0058] When the pressure inside the deaerator 3 is too high, the excessive pressure will activate the pressure relief valve 322 to release some of the gas inside the deaerator 3, thereby preventing a safety accident from occurring.
[0059] A steam utilization device for methanol synthesis operates as follows:
[0060] In operation, the black water discharged from scrubbing tower 1 (temperature approximately 180-220℃) is introduced into flash tank 2 for flash evaporation. During flash evaporation in flash tank 2, the black water enters through connecting pipe 231 and is atomized by sprayer 232. Part of the sprayed water undergoes flash evaporation to form steam due to the reduced pressure. Furthermore, the tapered structure of connecting pipe 231 increases the flow velocity exiting from it, facilitating atomization when sprayed from sprayer 232. While some of the black water flashes and vaporizes, solid impurities such as carbon in the black water mix with the steam. Therefore, as the steam is discharged, it passes through filter 22, which traps these solid impurities and also traps some water mist, thus increasing the dryness of the generated steam. Unvaporized water falls into the lower part of flash tank 2 and is discharged from the first drain port 203. The discharged black water still has a relatively high temperature (around 100℃). It is fed into the tube side of heat exchanger 4 to preheat the ash water supplied to deaerator 3 via water supply line 10 for heating and deoxygenation. The preheated black water is filtered through filter 5 and then fed into scrubbing tower 1 for use as washing water. Solid impurities intercepted by filter 5 are fed into boiler 6 and co-fired with pulverized coal as fuel. The steam output from flash tank 2 is partly fed into deaerator 3 to heat and deoxygenate the ash water fed into deaerator 3. The other part is fed into heating device 7 for use in sections requiring heating. Simultaneously, to prevent insufficient steam production from flash tank 2, steam line 20 is connected to deaerator 3 to supplement the steam supply.
[0061] After exchanging heat with the black water in the heat exchanger 4, the grey water is input from the inlet pipe 35 of the deaerator 3. As it falls, it lands on the umbrella-shaped distribution plate 341. Through the buffering and even distribution effect of the distribution plate 341, the grey water flow will impact and form small droplets that fall into the distribution plate 34, or form a liquid film under the even distribution of the distribution plate 341 and fall into the distribution plate 34, and then fall as droplets through the distribution holes opened on the distribution plate 34. Meanwhile, steam output from flash tank 2 is input through aeration pipe 33 to aerate the ash water in deaerator 3. The rising steam comes into countercurrent contact with the falling ash water droplets, heating the ash water droplets and reducing the solubility of oxygen in the ash water, thereby removing oxygen from the ash water. The oxygen removed from the ash water rises with the steam and enters the steam-water separator 32 through the connection between the steam-water separator 32 and the deaerator body 31. Since the discharged steam still contains a small amount of water mist, a multi-layer demister 321 is installed in the steam-water separator 32 to intercept the water mist in the upward discharged steam and reduce the loss of ash water.
[0062] When the pressure inside the deaerator 3 is too high, the excessive pressure will activate the pressure relief valve 322 to release some of the gas inside the deaerator 3, thereby preventing a safety accident from occurring.
[0063] Finally, it should be noted that 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. A steam utilization device for methanol synthesis, characterized in that, It includes a scrubbing tower (1), a flash tank (2), and a deaerator (3) connected in series. The flash tank (2) is also connected to the tube-side inlet of the heat exchanger (4), and the tube-side outlet of the heat exchanger (4) is also connected to the scrubbing tower (1). The shell-side inlet of the heat exchanger (4) is connected to the water supply pipeline (10), and the shell-side outlet of the heat exchanger (4) is connected to the deaerator (3).
2. The steam utilization device in methanol synthesis according to claim 1, characterized in that, A filter (5) is provided between the tube outlet of the heat exchanger (4) and the scrubbing tower (1), and the filter (5) is also connected to the boiler (6).
3. The steam utilization device in methanol synthesis according to claim 1, characterized in that, The flash tank (2) is connected to the heat tracing device (7) via a valve; The deaerator (3) is also connected to the steam line (20).
4. The steam utilization device in methanol synthesis according to claim 1, characterized in that, The flash tank (2) includes a tank body (21) and a filter screen (22) horizontally disposed inside the tank body (21). The tank (21) is provided with a steam outlet (201) and a vent valve (202) at the top and a first drain outlet (203) at the bottom. The tank (21) is also equipped with a spray device (23), which is located between the filter screen (22) and the first drain port (203) and is connected to the washing tower (1); The steam outlet (201) is connected to the deaerator (3), and the first drain port (203) is connected to the tube inlet of the heat exchanger (4).
5. The steam utilization device for methanol synthesis according to claim 4, characterized in that, The spraying device (23) includes a horizontally arranged connecting pipe (231), the output end of which is connected to the sprayer (232); The connecting tube (231) has a structure that tapers from the input end to the output end.
6. The steam utilization device in methanol synthesis according to claim 1, characterized in that, The deaerator (3) includes a deaerator body (31), the top of which is connected to the steam-water separator (32). An aeration pipe (33) is provided at the bottom of the deaerator body (31), and the aeration pipe (33) is connected to the flash tank (2). The inner top of the deaerator body (31) is suspended by a connecting beam and a liquid distribution plate (34). The bottom of the liquid distribution plate (34) is provided with multiple liquid distribution holes. Multiple umbrella-shaped liquid distribution plates (341) are vertically arranged on the upper surface of the liquid distribution plate (34). Each liquid distribution plate (341) corresponds one-to-one with the liquid inlet pipe (35) opened at the top of the deaerator body (31). The deaerator body (31) has a second drain port (301) at its bottom.
7. The steam utilization device for methanol synthesis according to claim 6, characterized in that, The steam-water separator (32) is horizontally provided with a multi-layer demister (321), and the aperture of the multi-layer demister (321) decreases sequentially along the steam flow direction. The top of the steam-water separator (32) is connected to a pressure relief valve (322).