Desorption liquid flash component, desorption tower and CO2 capture device

Abstract

The application discloses a desorption liquid flash component, a desorption tower and a CO2 capture device. The desorption liquid flash component is arranged in a tower kettle of the desorption tower and comprises a distribution pipe and at least one discharge cylinder. The discharge cylinder is in the shape of a horn with an opening upward. The cylinder wall of the discharge cylinder is uniformly provided with a plurality of through holes which are inclined upward from inside to outside. The bottom of the discharge cylinder is communicated with the distribution pipe, the distribution pipe can be communicated with lean amine liquid, and the lean amine liquid is distributed to the at least one discharge cylinder. The desorption liquid flash component for the desorption tower of the CO2 capture device can realize pressure reduction overflow type flash, increase disturbance to fluid, play a role of stirring stripping, make flash more sufficient, improve heat recycling efficiency, and reduce energy consumption.

Description

Technical Field

[0001] This invention relates to the field of desorption technology, and in particular to a flash evaporation element for desorption liquid, a desorption tower, and a CO2 capture device. Background Technology

[0002] In CO2 capture technology, chemical absorption capture technology, which mainly uses organic amine liquid, has become the main technology for large-scale industrial application. In this type of technology, in order to achieve comprehensive energy utilization in the CO2 desorption tower, the steam at the top of the tower can be recovered. The recovered heat can be used to heat the lean amine liquid in the bottom of the tower through a heat pump system, thereby reducing the heating load of the reboiler. Summary of the Invention

[0003] To enrich the product range of desorbent flash evaporation components and increase the selection space for desorbent flash evaporation methods, this invention provides a desorbent flash evaporation and desorption tower for CO2 capture.

[0004] In a first aspect, embodiments of the present invention provide a desorption liquid flash evaporation element, disposed in the bottom of a desorption tower, comprising a distribution pipe and at least one venting cylinder;

[0005] The vent is shaped like a funnel with its opening facing upwards;

[0006] The wall of the discharge cylinder is evenly provided with several through holes that slope upwards from the inside out.

[0007] The bottom of the venting cylinder is connected to the distribution pipe, which allows lean amine solution to be introduced and distributed to at least one venting cylinder.

[0008] In one or more alternative embodiments, the distribution pipe is a ring-shaped distribution pipe.

[0009] In one or more alternative embodiments, the at least one venting cylinder is evenly distributed above the distribution pipe.

[0010] In one or more alternative embodiments, the angle between the centerline of the venting cylinder and the cylinder wall is greater than 15°.

[0011] In one or more alternative embodiments, the height of the vent cylinder is greater than 500 mm.

[0012] In one or more alternative embodiments, the through-hole is inclined upward at 45° from the inside out.

[0013] In one or more alternative embodiments, the through hole is an elliptical hole.

[0014] In one or more alternative embodiments, the inner diameter of the through hole is greater than or equal to 10 mm and less than or equal to 30 mm.

[0015] Secondly, embodiments of the present invention provide a desorption tower, including the desorption liquid flash evaporator described in the first aspect.

[0016] Thirdly, embodiments of the present invention provide a CO2 capture device, including a heat pump system and the desorption tower described in the second aspect.

[0017] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0018] The desorption liquid flash evaporator provided in this embodiment of the invention has a distribution pipe that can distribute lean amine liquid from the heat pump system to one or more venting cylinders. The heated lean amine liquid can be discharged through the venting cylinders, thereby achieving pressure reduction overflow flash evaporation in the desorption tower bottom. The overflowing lean amine liquid flows downward along the venting cylinder. Since the cylinder wall of the venting cylinder is uniformly provided with several through holes that slope upward from the inside out, the lean amine liquid sprayed from the through holes increases the disturbance to the fluid, playing a role in stirring and stripping, making the flash evaporation more complete, improving the heat recovery and utilization efficiency, and reducing energy consumption.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a front view of the desorption liquid flash evaporation component provided in an embodiment of the present invention;

[0023] Figure 2 This is a top view of the desorption liquid flash evaporation element provided in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of the venting cylinder provided in an embodiment of the present invention;

[0025] Figure 4 This is a partial structural schematic diagram of the CO2 capture device provided in an embodiment of the present invention.

[0026] In the picture:

[0027] 1. Desorption liquid flash evaporation component; 11. Distribution pipe; 12. Drainage cylinder; 121. Through hole;

[0028] 100. Desorption tower; 101. Mass transfer element;

[0029] 200. Heat pump system;

[0030] 300. Reboiler. Detailed Implementation

[0031] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," 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 invention 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The inventors discovered that in CO2 capture technology, although the top vapor of the desorption tower can be recovered and the recovered heat can be used to heat the lean amine solution in the tower bottom through a heat pump system, thereby reducing the heating load of the reboiler, the lean amine solution, after being heated by the heat pump system, returns to the desorption tower bottom with increased pressure and temperature, and flashes in the tower bottom. Due to the large flow rate of the heated lean amine solution, it is easy to have insufficient flashing in the tower bottom, resulting in ineffective circulation and low efficiency of heat recovery and utilization.

[0035] Based on this, the present invention provides a desorption liquid flash evaporation element, a desorption tower, and a CO2 capture device, which will be described in detail below through specific embodiments.

[0036] Example 1

[0037] This invention provides a flash evaporator 1 for desorption liquid, as described in the following embodiment. Figures 1-4 As shown, the column bottom of the desorption tower 100 includes a distribution pipe 11 and at least one venting cylinder 12;

[0038] The venting cylinder 12 is in the shape of a funnel with its opening facing upwards;

[0039] The wall of the discharge cylinder 12 is evenly provided with a plurality of through holes 121 that slope upward from the inside out;

[0040] The bottom of the venting cylinder 12 is connected to the distribution pipe 11, which is capable of transmitting high-temperature liquid and distributing the high-temperature liquid to the at least one venting cylinder 12.

[0041] In this embodiment of the invention, since multiple through holes 121 are provided, after the lean amine liquid is distributed to the venting cylinder 12, it will not only overflow from the upper opening of the venting cylinder 12, but also spray out from the multiple through holes 121, thereby increasing the surface area of ​​the lean amine liquid, improving the efficiency of gas-liquid separation, and thus increasing the disturbance of the lean amine liquid in the bottom of the desorption tower 100.

[0042] In the desorption process, to address the problem of incomplete flash evaporation caused by a large flow rate of lean amine solution, refer to... Figure 1 and Figure 4 As shown, the desorption flash evaporator 1 described in this embodiment can be installed in the bottom of the desorption tower 100 and connected to the lean amine outlet of the heat pump, so that the heated lean amine can be introduced into the desorption flash evaporator. Since the venting cylinder 12 is a funnel shape with its opening facing upward, and the cylinder wall is uniformly provided with several through holes 121 that slope upward from the inside to the outside, after the distribution pipe 11 distributes the heated lean amine into the venting cylinder 12, the lean amine can overflow from the opening of the venting cylinder 12, realizing pressure-reducing overflow flash evaporation. Some of the lean amine will also spray out from the through holes 121 in the cylinder wall of the venting cylinder 12, thereby greatly increasing the disturbance to the lean amine in the bottom of the tower, having a stirring stripping effect, and making the flash evaporation more complete.

[0043] The desorption liquid flash evaporator 1 provided in this embodiment of the invention has a distribution pipe 11 that can distribute lean amine liquid from the heat pump system 200 to one or more venting cylinders 12. The heated lean amine liquid can be discharged through the venting cylinder 12, and then undergo pressure reduction overflow flash evaporation in the bottom of the desorption tower 100. The overflowing liquid flows downward along the venting cylinder 12. Since the cylinder wall of the venting cylinder 12 is uniformly provided with several through holes 121 that are inclined upward from the inside to the outside, the liquid sprayed from the through holes 121 increases the disturbance to the fluid, plays a role in stirring and stripping, makes the flash evaporation more complete, improves the heat recovery and utilization efficiency, and reduces energy consumption.

[0044] In one specific embodiment, the specific number of discharge cylinders 12 can be reasonably set according to the flow rate of the lean amine solution. For example, when the flow rate of the lean amine solution is large, more than four discharge cylinders 12 can be set, and when the flow rate of the lean amine solution is small, two discharge cylinders 12 can be set. In this embodiment, considering both space occupation and the flow rate of the lean amine solution, refer to... Figure 2 As shown, four discharge cylinders 12 are set up to ensure reasonable space occupancy while being suitable for large flow rates of lean amine solution.

[0045] In one specific embodiment, reference is made to Figure 2 As shown, the distribution pipe 11 can be an annular pipe. When there are two or more discharge cylinders 12, each discharge cylinder 12 is evenly distributed above the distribution pipe 11, so that the distribution pipe 11 can evenly distribute the heated lean amine liquid to each discharge cylinder 12. The lean amine liquid is then discharged through the discharge cylinder 12 to achieve pressure reduction overflow flash evaporation.

[0046] In one specific embodiment, the connection between the discharge cylinder 12 and the distribution pipe 11 is a liquid inlet, and the size of the liquid inlet and the opening can be reasonably set according to the flow rate of the lean amine liquid.

[0047] In one specific embodiment, the height of the venting cylinder 12 can be set to be greater than 500mm to ensure sufficient flash evaporation space. If the height of the venting cylinder 12 is less than 500mm, the space inside the cylinder will be too small, resulting in insufficient flash evaporation of the lean amine solution after it enters the venting cylinder 12. Therefore, the height of the venting cylinder 12 should be set to be greater than 500mm, and the higher the height, the more complete the flash evaporation. The specific height of the venting cylinder 12 needs to be designed according to the dimensions of the desorption tower 100. However, if the height is too high, it will also lead to excessive equipment costs, which is not conducive to improving economic efficiency. In particular, when the height is greater than 1200mm, the required equipment investment is large. Therefore, the height of the venting cylinder 12 can be set between 500mm and 1200mm.

[0048] In one specific embodiment, the angle between the centerline of the venting cylinder 12 and its wall affects the flash evaporation effect. Specifically, if the angle between the centerline of the venting cylinder 12 and its wall is less than 15°, the difference in size between the upper opening and the lower liquid inlet of the venting cylinder 12 will be too small, resulting in the lean amine liquid not being able to effectively reduce pressure and overflow, thus leading to insufficient flash evaporation. Therefore, the angle between the centerline of the venting cylinder 12 and its wall is set to be greater than 15°. Furthermore, the inventors have verified through experiments that the larger the angle between the centerline of the venting cylinder and its wall, the more sufficient the flash evaporation of the lean amine liquid. However, if the angle between the centerline of the venting cylinder 12 and its wall is greater than 30°, it will result in excessive space occupation and excessive equipment investment. Therefore, the angle between the centerline of the venting cylinder 12 and its wall can be set between 15° and 30°.

[0049] In one specific embodiment, the shape of the through hole 121 can be circular, elliptical, etc., as long as it can ensure that the lean amine liquid can be smoothly sprayed out from the cylinder wall of the discharge cylinder 12. The inventors have verified through experiments that when the shape of the through hole 121 is elliptical, the surface area of ​​the lean amine liquid is the largest when it flows out, which can cause greater disturbance to the lean amine liquid in the bottom of the desorption tower 100. Therefore, in this embodiment, the shape of the through hole 121 is set to elliptical.

[0050] In one specific embodiment, the angle at which the through hole 121 is tilted upward from the inside out affects the speed at which the lean amine liquid flows out of the through hole 121. Specifically, the smaller the angle at which the through hole 121 is tilted upward from the inside out, the faster the lean amine liquid flows out; conversely, the larger the angle at which the through hole 121 is tilted upward from the inside out, the slower the lean amine liquid flows out. Setting the angle at which the through hole 121 is tilted upward from the inside out to 45° can ensure the flow rate of the lean amine liquid while making the speed at which it is ejected from the through hole 121 appropriate, thereby increasing the disturbance to the lean amine liquid.

[0051] In one specific embodiment, the inner diameter of the through-hole 121 also affects the flow rate of the lean amine liquid from the through-hole 121 and its pressure-holding effect within the through-hole 121. Experimental verification by the inventors revealed that when the inner diameter of the through-hole 121 is less than 10 mm, the resistance to the lean amine liquid entering the through-hole 121 is greater, resulting in excessive pressure-holding and a smaller flow rate of the discharged lean amine liquid, failing to provide a significant disturbance effect. Conversely, when the inner diameter of the through-hole 121 is greater than 30 mm, the resistance to the lean amine liquid entering the through-hole 121 is too small, resulting in no significant pressure-holding effect and a smaller impact force of the discharged lean amine liquid, which is also not conducive to strengthening the disturbance. The inner diameter of the through-hole 121 can be greater than or equal to 10 mm and less than or equal to 30 mm to ensure a better disturbance effect. It should be noted that when the through-hole 121 is a circular hole, the inner diameter of the through-hole 121 refers to the diameter of the circular hole; when the through-hole 121 is an elliptical hole, the inner diameter of the through-hole 121 refers to the major axis of the elliptical hole.

[0052] The desorption liquid flash evaporation component 1 provided in this embodiment of the invention can evenly distribute lean amine liquid to each discharge cylinder 12 through the distribution pipe 11. The flared opening of the discharge cylinder 12 can realize the pressure-reduced overflow of lean amine liquid. By reasonably setting the inclination angle and inner diameter of the through hole 121 in the cylinder wall of the discharge cylinder 12, the disturbance effect on the lean amine liquid can be maximized, thereby realizing the full flash evaporation of lean amine liquid, improving the heat recovery and utilization efficiency, and reducing the energy consumption of flash evaporation.

[0053] Example 2

[0054] Based on the same inventive concept, this invention also provides a desorption tower 100, referring to... Figure 4 As shown, it includes the desorption liquid flash evaporator 1 described in Example 1, and the desorption liquid flash evaporator 1 is disposed in the bottom of the desorption tower 100.

[0055] The desorption tower 100 provided in this embodiment of the invention is used to desorb CO2-absorbent (rich amine liquid). Specifically, the rich amine liquid is introduced from the top of the desorption tower 100 and flows through the mass transfer element 101 inside the tower, where it fully exchanges heat with the rising hot steam inside the tower, allowing the CO2 in the rich amine liquid to be separated. The lean amine liquid, heated by the heat pump system, is then introduced into the desorption liquid flash evaporator 1 of the desorption tower for flash evaporation. Through the stirring and stripping action of the desorption liquid flash evaporator 1, the steam in the lean amine liquid is fully flashed out, improving the heat recovery and utilization efficiency and effectively improving the CO2 desorption efficiency.

[0056] Example 3

[0057] Based on the same inventive concept, embodiments of the present invention also provide a CO2 capture device, referring to... Figure 4 As shown, it includes a heat pump system 200 and a desorption tower 100 as described in Embodiment 2.

[0058] In this embodiment of the invention, reference is made to Figure 4 As shown, the heat pump system 200 is connected to the first lean liquid outlet of the desorption tower 100 and the inlet of the distribution pipe 11. The lean liquid in the bottom of the desorption tower 100 flows into the heat pump system 200. The heat pump system 200 can recover the low-grade waste heat in the system. The recovered heat is used to heat the lean liquid. The heated lean liquid flows into the distribution pipe 11 for flash evaporation, thereby improving the efficiency of heat recovery and utilization and reducing energy consumption.

[0059] In this embodiment of the invention, reference is made to Figure 4 As shown, the CO2 capture device may also include a reboiler 300, which is connected to the second lean liquid outlet and the lean liquid inlet of the desorption tower 100. The lean liquid heated by the reboiler 300 is returned to the bottom of the desorption tower 100 for further flash evaporation. Obviously, the reboiler 300 can also be connected to the inlet of the distribution pipe 11 of the desorption liquid flash evaporation element 1, thereby enhancing the flash evaporation effect of the lean amine liquid heated by the reboiler 300.

[0060] In this embodiment of the invention, the CO2 capture device may further include an absorption tower (not shown in the figure) for absorbing CO2 in the waste gas, and the rich amine liquid outlet of the absorption tower is connected to the rich amine liquid inlet of the desorption tower 100.

[0061] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A flash evaporator for desorption liquid, installed in the bottom of a desorption tower, characterized in that, Includes a distribution pipe and at least one venting tube; The vent is shaped like a funnel with its opening facing upwards; The wall of the discharge cylinder is evenly provided with several through holes that slope upwards from the inside out. The bottom of the venting cylinder is connected to the distribution pipe, which allows lean amine solution to be introduced and distributed to at least one venting cylinder.

2. The flash evaporator for desorption liquid according to claim 1, characterized in that, The distribution pipe is a ring-shaped distribution pipe.

3. The flash evaporator for desorption liquid according to claim 2, characterized in that, The at least one venting cylinder is evenly distributed above the distribution pipe.

4. The flash evaporator for desorption liquid according to claim 1, characterized in that, The angle between the centerline of the venting cylinder and the cylinder wall is greater than 15°.

5. The flash evaporator for desorption liquid according to claim 1, characterized in that, The height of the vent cylinder is greater than 500mm.

6. The flash evaporator for desorption liquid according to claim 1, characterized in that, The through hole is inclined upward at 45° from the inside out.

7. The flash evaporator for desorption liquid according to claim 1, characterized in that, The through hole is an elliptical hole.

8. The flash evaporator for desorption liquid according to claim 7, characterized in that, The inner diameter of the through hole is greater than or equal to 10 mm and less than or equal to 30 mm.

9. A desorption tower, characterized in that, Includes the desorption liquid flash evaporator as described in any one of claims 1-8.

10. A CO2 capture device, characterized in that, Includes a heat pump system and the desorption tower as described in claim 9.

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