Methanol waste gas recovery system
Through the combination of the first-stage water absorption tower and the second-stage water absorption tower, the problems of high investment, high energy consumption and unstable operation in the treatment of high-concentration methanol waste gas in the methanol tank area and loading and unloading truck platform are solved, and the stable management effect of low-cost and low energy consumption is achieved.
Patent Information
- Application Number
- CN202422337637.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-09-25
AI Technical Summary
The management of high concentration methanol waste gas in the methanol tank area and loading and unloading truck platform has problems such as high investment, high energy consumption and unstable operation, and it is especially difficult to cope with large concentration fluctuations.
The first-stage water absorption tower and the second-stage water absorption tower are combined with the adsorption and desorption unit, and the activated carbon adsorber is used to adsorb methanol. Through the multi-stage absorption and desorption process, combined with the circulation pump and the cooler to optimize the process, stable absorption and energy consumption are achieved.
It improves the stability and efficiency of methanol absorption, reduces energy consumption, adapts to working conditions with large concentration fluctuations, reduces equipment load and reduces operating costs.
Smart Images
Figure CN223082538U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of chemical waste gas recovery and treatment, in particular to a methanol waste gas recovery system. Background Art
[0002] In current industrial production, environmental protection issues have attracted increasing attention. Methanol, as an important chemical raw material, is widely used in various fields. Among them, methanol tank farms and loading and unloading vehicle platforms particularly generate high-concentration methanol waste gas during production and transportation.
[0003] However, the treatment of high-concentration methanol waste gas from methanol tank farms and loading and unloading vehicle platforms has always been a difficult problem. Such waste gas emissions have obvious characteristics, with large emission fluctuations, and the air volume and concentration will show large fluctuations in a short time, which poses a great challenge to waste gas treatment.
[0004] In the existing treatment processes, the cryogenic process is a relatively common method. However, the cryogenic process has some obvious defects. On the one hand, the investment cost of the cryogenic process is relatively high, which is a huge economic burden for enterprises; on the other hand, the operation energy consumption of this process is high, increasing the production cost of enterprises; in addition, the cryogenic process is also unstable during operation and cannot guarantee continuous and effective treatment of high-concentration methanol waste gas.
[0005] Activated carbon, as a good adsorption material, has good adsorption effects on organic substances in sewage and VOCs in waste gas, can purify sewage and waste gas to a certain extent, protect the environment, and is widely used in various industries. However, there is currently no effective treatment solution for high-concentration methanol waste gas from methanol tank farms and loading and unloading vehicle platforms that can give full play to the adsorption advantages of activated carbon while overcoming the problems of high investment, high energy consumption, and unstable operation of the existing treatment processes. Summary of the Utility Model
[0006] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a methanol waste gas recovery system with stable operation, low energy consumption, low cost, and capable of adapting to working conditions with large fluctuations.
[0007] The utility model solves its technical problems by adopting the following technical solutions:
[0008] A methanol waste gas recovery system includes: a primary water absorption tower, a secondary water absorption tower, a dryer, an exhaust gas fan, a first cooler, and an adsorption and desorption unit. The first outlet end at the top of the primary water absorption tower is connected to the first inlet end at the bottom of the secondary water absorption tower. The first outlet end at the top of the secondary water absorption tower is connected to the inlet end of the dryer. The outlet end of the dryer is connected to the inlet end of the exhaust gas fan. The outlet end of the exhaust gas fan is connected to the adsorption and desorption unit. The outlet end of the first cooler is connected to the second inlet end at the top of the secondary water absorption tower.
[0009] Moreover, it further includes a first circulation pump and a second cooler. The second outlet end at the bottom of the secondary water absorption tower is connected to the inlet end of the first circulation pump. The outlet end of the first circulation pump is connected to the inlet end of the second cooler. The first outlet end of the second cooler is connected to the third inlet end of the secondary absorption tower. The second outlet end of the second cooler is connected to the first inlet end of the primary water absorption tower.
[0010] Moreover, it further includes a second circulation pump and a third cooler. The second outlet end of the primary water absorption tower is connected to the inlet end of the second circulation pump. The outlet end of the second circulation pump is connected to the inlet end of the third cooler. The first outlet end of the third cooler is connected to the second inlet end of the primary water absorption tower. The second outlet end of the third cooler is connected to the methanol aqueous solution tank.
[0011] Moreover, the adsorption and desorption unit includes a first activated carbon adsorber, a second activated carbon adsorber, a drying fan, and a fourth cooler. The outlet end of the exhaust gas fan is respectively connected to the inlet end at the bottom of the first activated carbon adsorber and the inlet end at the bottom of the second activated carbon adsorber. The outlet end at the bottom of the first activated carbon adsorber and the outlet end at the bottom of the second activated carbon adsorber are connected to the inlet end of the fourth cooler. The outlet end of the drying fan is respectively connected to the inlet end at the bottom of the first activated carbon adsorber and the inlet end at the bottom of the second activated carbon adsorber.
[0012] Moreover, the outlet end of the fourth cooler is connected to the third inlet end at the bottom of the primary water absorption tower.
[0013] The advantages and positive effects of the present utility model are:
[0014] Compared with the traditional cryogenic process, when the concentration of methanol fluctuates greatly, the cryogenic process will cause untimely adjustment, resulting in a large fluctuation in the outlet concentration. The present utility model first absorbs methanol by using a primary water absorption tower and a secondary water absorption tower, and then uses the adsorption and desorption unit for adsorption, which can well handle the absorption of high-concentration methanol and the situation of large fluctuations in methanol concentration.
[0015] By adopting a secondary water absorption tower, the present utility model can timely absorb the increased concentration, effectively avoiding the situation that the outlet concentration is relatively high caused by insufficient water replenishment when the methanol concentration suddenly increases, which in turn leads to an increase in the load of subsequent equipment, improving the absorption efficiency of methanol and enhancing the stability of methanol absorption. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic structural diagram of the present utility model.
[0017] REFERENCE NUMERALS
[0018] 1 - Primary water absorption tower, 2 - Second circulation pump, 3 - Third cooler, 4 - First cooler, 5 - Secondary water absorption tower, 6 - First circulation pump, 7 - Second cooler, 8 - Tail gas fan, 9 - First activated carbon adsorber, 10 - Second activated carbon adsorber, 11 - Drying fan, 12 - Fourth cooler, 13 - 25 - Valves, 26 - Dryer. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] The present utility model will be further described in detail below in conjunction with the drawings and through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present utility model cannot be limited thereby.
[0020] A methanol waste gas recovery system includes: a primary water absorption tower 1, a secondary water absorption tower 5, a dryer 26, a tail gas fan 8, a first cooler 4 and an adsorption and desorption unit. The first outlet end at the top of the primary water absorption tower 1 is connected to the first inlet end at the bottom of the secondary water absorption tower 5. The first outlet end at the top of the secondary water absorption tower 5 is connected to the inlet end of the dryer 26. The outlet end of the dryer 26 is connected to the inlet end of the tail gas fan 8. The outlet end of the tail gas fan 8 is connected to the adsorption and desorption unit. The outlet end of the first cooler 4 is connected to the second inlet end at the top of the secondary water absorption tower 5.
[0021] It further includes a first circulation pump 6 and a second cooler 7. The second outlet end at the bottom of the secondary water absorption tower 5 is connected to the inlet end of the first circulation pump 6. The outlet end of the first circulation pump 6 is connected to the inlet end of the second cooler 7. The first outlet end of the second cooler 7 is connected to the third inlet end of the secondary absorption tower. The second outlet end of the second cooler 7 is connected to the first inlet end of the primary water absorption tower 1.
[0022] It further includes a second circulation pump 2 and a third cooler 3. The second outlet end of the primary water absorption tower 1 is connected to the inlet end of the second circulation pump 2. The outlet end of the second circulation pump 2 is connected to the inlet end of the third cooler 3. The first outlet end of the third cooler 3 is connected to the second inlet end of the primary water absorption tower 1. The second outlet end of the third cooler 3 is connected to the methanol aqueous solution tank.
[0023] In the embodiment of the present utility model, the tail gas first enters the primary water absorption tower 1, passes through the packing from the bottom of the primary water absorption tower 1 into the upper layer of the tower, contacts the absorption liquid countercurrently, and finally enters the secondary water absorption tower 5 through the pipeline at the top of the tower; the tail gas entering the secondary water absorption tower 5 passes through the packing from the bottom of the secondary water absorption tower 5 into the upper layer of the tower, contacts the absorption liquid countercurrently, and finally enters the dryer 26 through the pipeline at the top of the secondary water absorption tower 5 to remove moisture, and then enters the tail gas fan 8 for pressurization, and then is sent to the adsorption and desorption unit for adsorption.
[0024] Subsequently, the valve 15 is opened, and the fresh water is cooled to 20 - 25 °C by the first cooler 4 and enters the secondary water absorption tower 5 through the pipeline where the valve 15 is located, and the packing in the upper layer at the top of the tower absorbs methanol.
[0025] The valve 14 is opened, and the circulating liquid of the secondary water absorption tower 5 is transported by the first circulation pump 6 to the second cooler 7 for cooling to about 25 °C. Part of it enters the lower packing of the secondary water absorption tower 5 to absorb methanol, and the other part is sent to the primary water absorption tower 1 through the pipeline where the valve 14 is located, and the packing in the upper layer at the top of the tower absorbs methanol. The valve 13 is opened, and the circulating liquid of the primary water absorption tower 1 is transported by the second circulation pump 2 to the third cooler 3 for cooling to about 25 °C. Part of it enters the lower packing to absorb methanol, and the other part is sent to the methanol aqueous solution tank through the pipeline where the valve 13 is located, and then sent to the distillation system for separation.
[0026] Moreover, the adsorption and desorption unit includes a first activated carbon adsorber 9, a second activated carbon adsorber 10, a drying fan 11, and a fourth cooler 12. The outlet end of the tail gas fan 8 is respectively connected to the inlet end at the bottom of the first activated carbon adsorber 9 and the inlet end at the bottom of the second activated carbon adsorber 10; the outlet ends at the bottom of the first activated carbon adsorber 9 and the second activated carbon adsorber 10 are connected to the inlet end of the fourth cooler 12; the outlet end of the drying fan 11 is respectively connected to the inlet end at the bottom of the first activated carbon adsorber 9 and the inlet end at the bottom of the second activated carbon adsorber 10.
[0027] The outlet end of the fourth cooler 12 is connected to the third inlet end at the bottom of the primary water absorption tower 1.
[0028] In the embodiment of the present utility model, in the adsorption and desorption unit, the adsorption process is first carried out. The first activated carbon adsorber 9 adsorbs first, the valves 17 and 23 are opened, and other valves are closed. The tail gas enters the first activated carbon adsorber 9 through the pipeline where the valve 17 is located for adsorption treatment, and the purified gas is discharged into the atmosphere through the pipeline where the valve 23 is located. When the first activated carbon adsorber 9 is saturated with adsorption, it stops working, the valves 17 and 23 are closed, and the first activated carbon adsorber 9 is subjected to steam desorption and cooling and drying. The second activated carbon adsorber 10 is switched to carry out adsorption, the valves 20 and 25 are opened, the tail gas enters the second activated carbon adsorber 10 through the pipeline where the valve 20 is located for adsorption treatment, and the purified gas is discharged into the atmosphere through the pipeline where the valve 25 is located. When the second activated carbon adsorber 10 is saturated with adsorption, it stops working, the valves 20 and 25 are closed, and the second activated carbon adsorber 10 is subjected to steam desorption and drying. The first activated carbon adsorber 9 is switched to carry out adsorption, and the work is carried out in a cycle. One of the two activated carbon adsorbers adsorbs, and the other is subjected to steam desorption and cooling and drying.
[0029] When the first activated carbon adsorber 9 is subjected to steam desorption, the valves 22 and 18 are opened, steam is transported through the pipeline where the valve 22 is located, and the activated carbon adsorber is heated to 100 °C. Subsequently, the steam comes out through the pipeline where the valve 18 is located and enters the fourth condenser for solvent recovery. The condensate and the mixed solution are connected to the bottom of the first water washing tower through a pipeline. When the steam desorption of the first activated carbon adsorber 9 is completed, the valves 22 and 18 are closed, and drying and cooling are carried out. When the first activated carbon adsorber 9 is drying and cooling, the valves 16 and 23 are opened, air is sent to the first activated carbon adsorber 9 by the drying fan 11 to cool the first activated carbon adsorber 9, and the hot air coming out is discharged to the outside through the pipeline where the valve 23 is located until the temperature of the first activated carbon adsorber 9 drops to 40 °C. When the drying and cooling of the first activated carbon adsorber 9 is completed, the valves 16 and 23 are closed, and it can enter the next adsorption process.
[0030] When the second activated carbon adsorber 10 is subjected to steam desorption, the valves 24 and 21 are opened, steam is transported through the pipeline where the valve 24 is located, and the activated carbon adsorber is heated to 100 °C. Subsequently, the steam comes out through the pipeline where the valve 21 is located and enters the fourth condenser for solvent recovery. The condensate and the mixed solution are connected to the bottom of the first water washing tower through a pipeline. When the steam desorption of the second activated carbon adsorber 10 is completed, the valves 24 and 21 are closed, and drying and cooling are carried out. When the second activated carbon adsorber 10 is drying and cooling, the valves 19 and 25 are opened, air is sent to the second activated carbon adsorber 10 by the drying fan 11 to cool the second activated carbon adsorber 10, and the hot air coming out is discharged to the outside through the pipeline where the valve 25 is located until the temperature of the second activated carbon adsorber 10 drops to 40 °C. When the drying and cooling of the second activated carbon adsorber 10 is completed, the valves 19 and 25 are closed, and it can enter the next adsorption process.
[0031] The first activated carbon adsorber 9 and the second activated carbon adsorber 10 simultaneously carry out the adsorption and regeneration (steam desorption + drying and cooling) processes, and this is repeated cyclically.
[0032] Although embodiments and drawings of the present utility model are disclosed for illustrative purposes, those skilled in the art can understand that: various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present utility model and the appended claims. Therefore, the scope of the present utility model is not limited to the content disclosed in the embodiments and drawings.
Claims
1. A methanol waste gas recovery system, characterized in that: It includes a primary water absorption tower, a secondary water absorption tower, a dryer, an exhaust gas fan, a first cooler and an adsorption and desorption unit. The first outlet end at the top of the primary water absorption tower is connected to the first inlet end at the bottom of the secondary water absorption tower. The first outlet end at the top of the secondary water absorption tower is connected to the inlet end of the dryer. The outlet end of the dryer is connected to the inlet end of the exhaust gas fan. The outlet end of the exhaust gas fan is connected to the adsorption and desorption unit. The outlet end of the first cooler is connected to the second inlet end at the top of the secondary water absorption tower.
2. The methanol waste gas recovery system according to claim 1, wherein: It further includes a first circulation pump and a second cooler. The second outlet end at the bottom of the secondary water absorption tower is connected to the inlet end of the first circulation pump. The outlet end of the first circulation pump is connected to the inlet end of the second cooler. The first outlet end of the second cooler is connected to the third inlet end of the secondary absorption tower. The second outlet end of the second cooler is connected to the first inlet end of the primary water absorption tower.
3. The methanol waste gas recovery system according to claim 1, characterized in that: It further includes a second circulation pump and a third cooler. The second outlet end of the primary water absorption tower is connected to the inlet end of the second circulation pump. The outlet end of the second circulation pump is connected to the inlet end of the third cooler. The first outlet end of the third cooler is connected to the second inlet end of the primary water absorption tower. The second outlet end of the third cooler is connected to the methanol aqueous solution tank.
4. The methanol waste gas recovery system according to claim 1, wherein: The adsorption and desorption unit includes a first activated carbon adsorber, a second activated carbon adsorber, a drying fan and a fourth cooler. The outlet end of the exhaust gas fan is respectively connected to the inlet end at the bottom of the first activated carbon adsorber and the inlet end at the bottom of the second activated carbon adsorber. The outlet end at the bottom of the first activated carbon adsorber and the outlet end at the bottom of the second activated carbon adsorber are connected to the inlet end of the fourth cooler. The outlet end of the drying fan is respectively connected to the inlet end at the bottom of the first activated carbon adsorber and the inlet end at the bottom of the second activated carbon adsorber.
5. The methanol waste gas recovery system according to claim 4, characterized in that: The outlet end of the fourth cooler is connected to the third inlet end at the bottom of the primary water absorption tower.