Modularized carbon dioxide absorption microchannel device and method for enhancing carbon dioxide absorption

Abstract

The invention relates to a modularized carbon dioxide absorption micro-channel device and a method for enhancing carbon dioxide absorption, the modularized carbon dioxide absorption micro-channel device comprises a reaction module, the reaction module is in a hollow tube shape, the cross section of the reaction module is square, and the reaction module is sequentially divided into a gradually-shrinking section, a stable section, a gradually-expanding section and a cutting section along the length direction of the reaction module; the tapered section is in a transverse conical table shape, and the inlet end of the tapered section is larger than the outlet end; the stabilizing section is in the shape of a uniform-section rectangular straight pipe, and the size of the section of the stabilizing section is the same as that of the outlet end of the reducing section; the divergent section is in a transverse conical table shape, and the inlet end of the divergent section is smaller than the outlet end; the cutting section is in a uniform-section rectangular straight pipe shape, the section size of the cutting section is the same as that of the outlet end of the divergent section, and a plurality of columnar bulges are arranged in the cutting section; and the plurality of reaction modules are connected in series. The reducing section is connected with the inlet section; and the cutting section is connected with the outlet section. Therefore, the carbon dioxide absorption process is subjected to multiple times of cyclic strengthening of compression-stabilization-expansion-segmentation, and step-by-step and deep removal of carbon dioxide is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to an industrial device, in particular a device for carbon dioxide absorption and a method for improving carbon dioxide absorption efficiency, and more particularly to a modular carbon dioxide absorption micro-channel device and a method for enhancing carbon dioxide absorption. BACKGROUND

[0002] With the advancement of the "carbon neutralization" goal, the capture and storage of carbon dioxide (CO2) in industrial flue gas has become a key technology to address climate change. The current mainstream technology mainly uses amine absorbent combined with traditional equipment such as packed tower, but there are the following obvious bottlenecks: 1) Such equipment is large and has high energy consumption, resulting in low mass transfer efficiency; 2) The absorbent in such equipment is prone to degradation and uneven flow, resulting in a very rough process control; 3) The flow field and mass transfer behavior in such equipment are difficult to predict, and the equipment occupies a wide area, making it difficult to scale up.

[0003] Micro-channel reactors provide a potential path to solve the above problems. Currently, the common micro-channel reactor is a straight-through type. This type of reactor mainly includes a straight pipe type reaction channel, which is connected to the raw gas and absorbent through a T-shaped or Y-shaped junction at the inlet, so that the gas-liquid two-phase flow in the straight pipe type micro-channel with constant cross-section and smooth inner wall, completing the absorption of carbon dioxide.

[0004] However, such devices have the following disadvantages: Insufficient interface update: the single-structure flow channel passively accepts the natural flow pattern formed at the inlet, and the gas-liquid interface lacks effective redistribution and update mechanism in the subsequent process, resulting in rapid decay of mass transfer driving force along the process.

[0005] Lack of active disturbance: the flow field cannot introduce periodic and controlled disturbance structures except for the initial shear at the inlet, making it difficult to continuously stretch, break and merge bubbles or droplets, limiting the improvement of mass transfer coefficient.

[0006] Poor operation flexibility: the performance of the reactor is highly dependent on the natural flow pattern (such as the plug flow) at the inlet, which is sensitive to operating parameters and difficult to accurately control, resulting in weak ability of the system to adapt to fluctuations in gas concentration or processing load.

[0007] Therefore, it is urgent to improve it in order to better meet the needs of production. SUMMARY

[0008] The present application aims to overcome the shortcomings of the prior art and provide a modular carbon dioxide absorption micro-channel device and a method for enhancing carbon dioxide absorption, which can effectively improve the mass transfer efficiency and purification depth, and realize the step-by-step and deep absorption of carbon dioxide.

[0009] The technical scheme of the present application is: A modular carbon dioxide absorption micro-channel device, comprising a reaction module, the reaction module is a hollow tubular, its cross section is square, and is sequentially divided into a tapered section, a stable section, an expanding section and a cutting section along its length direction; The tapered section is a transversely placed conical platform, its inlet end is larger than its outlet end; the stable section is an equal cross section rectangular straight tube, its cross section size is the same as the outlet end of the tapered section; the expanding section is a transversely placed conical platform, its inlet end is smaller than its outlet end; the cutting section is an equal cross section rectangular straight tube, its cross section size is the same as the outlet end of the expanding section, and a plurality of columnar protrusions are arranged in the cutting section, which can cut and disturb the flowing bubbles; Further comprising an inlet section; the inlet section comprises a horizontal pipe and a vertical pipe which are in communication; the inlet end of the horizontal pipe is connected to a flue gas source, and the outlet end thereof is connected to the inlet end of the tapered section; the inlet end of the vertical pipe is connected to an absorbent source, and the outlet end thereof is connected to the horizontal pipe; Further comprising an outlet section; the outlet section is a hollow straight tube, its inlet end is connected to the outlet end of the cutting section, and its outlet end is connected to a discharge device; The reaction module is a plurality of modules connected in series.

[0010] Further, the protrusions are cylindrical and are uniformly arranged in an array form, and the height of the protrusions is 1 / 3 to 1 / 2 of the height of the cutting section.

[0011] Further, the horizontal pipe and the vertical pipe are straight tubes, and their cross sections are square.

[0012] Further, the inlet section is a T-shaped structure.

[0013] Further, the cross section size of the horizontal pipe and the vertical pipe is the same as the size of the inlet end of the tapered section.

[0014] Further, the axial length of the tapered section is 1 to 3 times of the side length of the inlet end thereof; the axial length of the stable section is the same as the length of the tapered section; the axial length of the expanding section is 1 to 3 times of the side length of the outlet end thereof; and the axial length of the cutting section is the same as the axial length of the expanding section.

[0015] Further, the outlet section is an equal cross section straight tube, and its cross section size is the same as the cross section size of the cutting section.

[0016] Further, the reaction modules are detachably connected, and the reaction modules are detachably connected with the inlet section and the outlet section.

[0017] A method for enhancing carbon dioxide absorption, which applies the modular carbon dioxide absorption micro-channel device, comprising the following steps: 1) introducing the raw gas containing carbon dioxide and the basic absorption liquid into the inlet section respectively, preliminarily mixing to form a gas-liquid mixture, and establishing an initial slug flow or bubble flow pattern; 2) the gas-liquid mixture is gradually compressed through the converging section, the liquid phase circulation vortex in the gas bubble in the gas-liquid two-phase flow is enhanced, and the liquid film mass transfer resistance is reduced; 3) the gas-liquid mixture flows through the stabilization section, and the non-steady flow field generated by compression is preliminarily homogenized; 4) the gas-liquid mixture flows through the diverging section and is gradually expanded, so that the gas bubbles in the gas-liquid two-phase flow are reversely expanded and the interface is violently shaken, and stretching deformation occurs, so that the saturated gas-liquid interface is forced to be renewed, and new reaction interface is exposed; 5) the gas-liquid mixture flows through the cutting section, and the gas bubbles in the gas-liquid two-phase flow are mechanically cut and collided and merged by the protrusions, so that periodic vortex flow is formed, and the contact area and mass transfer coefficient of the gas phase and the liquid phase are improved; 6) the gas-liquid mixture flows out of the outlet section and enters the next process.

[0018] Further, the steps 2) to 5) are sequentially performed in each reaction module, so that the carbon dioxide absorption process undergoes multiple cycles of "compression-stabilization-expansion-segmentation" for enhancement.

[0019] The beneficial effects of the present application are: (1) significantly improving the mass transfer efficiency and purification depth: through the coordinated design of the flow channel of "converging section compression acceleration → stabilization section flow field homogenization → diverging section expansion shock → cutting section segmentation turbulence", the bubble shape and interface behavior are effectively regulated, and the gas-liquid mass transfer is enhanced. Multi-module series connection can form step-by-step absorption, thereby realizing deep removal.

[0020] (2) excellent operation flexibility and working condition adaptability: by increasing or decreasing the number of reaction modules, the system performance can be linearly adjusted, so that a set of system can economically and efficiently cope with various working conditions from low to high different concentrations and different treatment standards, solving the industry pain point of poor adaptability of fixed structure equipment.

[0021] (3) intrinsically safe, easy to scale up and maintain: the modular and standardized design concept makes industrial scaling up easy through simple "quantity scaling up", without traditional scaling effect. At the same time, the independent detachability of the module makes the cleaning, replacement and maintenance operation simple, greatly reducing the operation and maintenance cost and downtime. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the present application.

[0023] Figure 2 This is a schematic diagram of the internal structure of the cutting segment of the present invention.

[0024] Among them, 1-vertical pipe; 2-horizontal pipe; 3-recession section; 4-stabilizing section; 5-expansion section; 6-cutting section; 61-top plate; 62-protrusion; 63-bottom plate; 7-exit section. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 and 2 As shown, a modular carbon dioxide absorption microchannel device includes an inlet section, a reaction module, and an outlet section.

[0027] The reaction module is a hollow tube, which is divided into a tapering section 3, a stabilizing section 4, a expanding section 5, and a cutting section 6 along its length.

[0028] The tapered section 3 is a horizontally placed truncated cone shape, with its inlet end larger than its outlet end, used to compress and accelerate bubbles, enhancing internal circulation. Preferably, the cross-section of the tapered section 3 is square, with the side length of its outlet end being 1 / 4 to 1 / 2 of the side length of its inlet end, and its axial length being 1 to 3 times the side length of its inlet end.

[0029] The stabilizing section 4 is a rectangular straight tube with a square cross-section. The size of its port is the same as the size of the outlet end of the tapering section 3, and its axial length is the same as the length of the tapering section. It is used for the initial averaging of the flow field.

[0030] The expanding section 5 is a horizontally placed truncated cone shape, with its inlet end smaller than its outlet end. The size of its inlet end is the same as the size of the port of the stabilizing section 4, and the size of its outlet end is the same as the size of the inlet end of the contracting section 3. At the same time, the axial length of the expanding section 5 is 1 to 3 times the side length of its outlet end, which allows the flow channel to gradually expand, so as to cause the bubble to expand, the interface to oscillate, and the stretching deformation.

[0031] The cutting section 6 is a rectangular straight tube with a square cross-section. The size of this cross-section is the same as the size of the outlet end of the expanding section 5, and its axial length is the same as the axial length of the expanding section 5. Simultaneously, the cutting section has multiple columnar protrusions inside to cut and turbulent the flowing bubbles.

[0032] The protrusions 62 are cylindrical, uniformly arranged in an array on the bottom plate 63 of the cutting section 6, and have a height of 1 / 3 to 1 / 2 of the distance between the top plate 61 and the bottom plate 63 of the cutting section 6, for mechanically cutting and merging the bubbles in the flow, and thinning the liquid film boundary layer by generating strong periodic vortex flow, so as to achieve extreme local active intensification of the gas-liquid mass transfer process. Preferably, the protrusion array is arranged in a 3-row-by-5-column array.

[0033] The inlet section includes a horizontal pipe 2 and a vertical pipe 1. Both the horizontal pipe and the vertical pipe are equal-section rectangular straight pipes, and are connected to each other to form a T-shaped structure. The inlet end of the horizontal pipe 2 is connected to a flue gas source, and the outlet end thereof is connected to the inlet end of the tapered section 3. The inlet end of the vertical pipe 1 is connected to an absorbent source, and the outlet end thereof is connected to the horizontal pipe 2. Thus, the basic absorbent can be mixed with the carbon dioxide-containing gas to realize initial contact and bubble generation of the gas-liquid two-phase flow. Preferably, the horizontal pipe and the vertical pipe have the same cross-sectional size, and the size of the cross section is the same as that of the inlet end of the tapered section, and the side length is 0.4-4 mm.

[0034] The outlet section 7 is a hollow straight pipe, the inlet end of which is connected to the outlet end of the cutting section, and the outlet end thereof is connected to a discharge device, so as to discharge the treated carbon dioxide-containing gas. Preferably, the outlet section 7 is of equal cross section, and the size of the cross section is the same as that of the cutting section.

[0035] The reaction modules are connected in series, so that the carbon dioxide absorption process undergoes multiple cycles of “compression-stabilization-expansion-segmentation” intensification, thereby realizing step-by-step and deep removal of carbon dioxide.

[0036] The reaction modules are detachably connected, for example, by using standardized interfaces such as flanges or clamps, so that the reaction modules can be conveniently assembled and disassembled, and the number of the reaction modules can be adjusted, so that the total processing capacity and the purification depth of the reactor can be flexibly configured according to the requirements of the inlet carbon dioxide concentration and the processing gas volume.

[0037] The application also provides a method for intensifying carbon dioxide absorption, which applies the modular carbon dioxide absorption micro-channel device, and comprises the following steps: 1) The basic absorbent and the raw gas containing carbon dioxide are introduced into the inlet section, so as to form a gas-liquid mixture, and under the shearing action of the T-shaped structure, a dispersed phase unit with controllable size is formed, and an initial plug flow or bubble flow pattern is established.

[0038] 2) The gas-liquid mixture flows through the tapered section of the reaction module, the bubbles in the gas-liquid two-phase flow are axially compressed and radially stretched, and the flow is accelerated, the liquid phase circulation vortex flow in the bubble is intensified, and the liquid film mass transfer resistance is reduced, by the continuous reduction of the flow passage cross-sectional area.

[0039] 3) The gas-liquid mixture flows through the stable section of the reaction module, and flows in the equal cross-section flow channel, so that the non-steady flow field generated by the compression is preliminarily homogenized, and a stable flow basis is established for the subsequent interface disturbance.

[0040] 4) The gas-liquid mixture flows through the gradually expanding section of the reaction module, and through the continuous increase of the flow channel cross-sectional area, the gas bubbles in the gas-liquid two-phase flow are reversely expanded and the interface is violently shaken, and stretching deformation occurs, so that the saturated gas-liquid interface is forced to be updated, and a new reaction interface is exposed.

[0041] 5) The gas-liquid mixture flows through the cutting section, so that the gas bubbles in the flow are subjected to mechanical cutting and collision and merging of the regularly arranged cylindrical protrusions, and strong periodic vortexes are generated behind the protrusions, realizing further subdivision of the gas phase and extreme micro-mixing of the liquid phase, so that the interfacial contact area and the mass transfer coefficient are maximized.

[0042] 6) The gas-liquid mixture continues to flow into the next reaction module, and steps 2) to 5) are repeated, so that the carbon dioxide absorption process undergoes multiple cycles of "compression-stabilization-expansion-segmentation", realizing step-by-step and deep removal of carbon dioxide.

[0043] 7) The gas-liquid mixture flows out from the outlet section and enters the next process.

[0044] Therefore, the mass transfer efficiency and purification depth can be effectively improved, the step-by-step and deep absorption of carbon dioxide is realized, and the treatment efficiency of the carbon dioxide-containing gas is improved.

[0045] The part not involved in the present application is the same as or can be realized by the prior art.

Claims

1. A modular carbon dioxide absorption microchannel device, comprising a reaction module, characterized in that, The reaction module is a hollow tubular shape with a square cross-section, and is divided into a tapering section, a stabilizing section, a expanding section and a cutting section along its length. The converging section is a horizontally placed truncated cone shape, with its inlet end larger than its outlet end; the stabilizing section is a rectangular straight tube with a uniform cross-section, the same size as the outlet end of the converging section; the expanding section is a horizontally placed truncated cone shape, with its inlet end smaller than its outlet end; the cutting section is a rectangular straight tube with a uniform cross-section, the same size as the outlet end of the expanding section, and has multiple columnar protrusions inside, which can cut and turbulent the flowing bubbles. It also includes an inlet section; the inlet section includes a horizontal pipe and a vertical pipe that are interconnected; the inlet end of the horizontal pipe is connected to the flue gas source, and its outlet end is connected to the inlet end of the converging section; the inlet end of the vertical pipe is connected to the absorbent source, and its outlet end is connected to the horizontal pipe. It also includes an outlet section; the outlet section is a hollow straight tube, the inlet end of which is connected to the outlet end of the cutting section, and the outlet end is connected to the discharge device. The reaction modules are multiple and connected in series.

2. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The protrusions are cylindrical and arranged evenly in an array, with a height of 1 / 3 to 1 / 2 of the height of the cut segment.

3. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The inlet section has a T-shaped structure.

4. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, Both the horizontal and vertical pipes are straight pipes, and their cross-sections are square.

5. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The horizontal and vertical tubes have the same cross-sectional size, and the same size as the inlet end of the tapering section.

6. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The axial length of the tapering section is 1 to 3 times the side length of its inlet end; the axial length of the stabilizing section is the same as the length of the tapering section; the axial length of the expanding section is 1 to 3 times the side length of its outlet end; and the axial length of the cutting section is the same as the axial length of the expanding section.

7. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The outlet section is a straight pipe with a uniform cross-section, and its cross-sectional size is the same as that of the cut section.

8. The modular carbon dioxide absorption microchannel device according to claim 1, characterized in that, The reaction modules are detachably connected to each other, as are the reaction modules and the inlet and outlet sections.

9. A method for enhancing carbon dioxide absorption, characterized in that, This method, employing the modular carbon dioxide absorption microchannel device according to any one of claims 1-8, includes the following steps: 1) The raw gas containing carbon dioxide and the alkaline absorbent are introduced into the inlet section respectively, and they are initially mixed to form a gas-liquid mixture, and an initial slug flow or bubble flow pattern is established; 2) The gas-liquid mixture is gradually compressed as it passes through the converging section, which enhances the liquid phase circulation eddy inside the bubbles in the gas-liquid two-phase flow and reduces the resistance to liquid film mass transfer. 3) The gas-liquid mixture flows through the stable section, which initially homogenizes the unsteady flow field generated by compression; 4) As the gas-liquid mixture flows through the diffuser section, it gradually expands, causing the bubbles in the gas-liquid two-phase flow to expand in the opposite direction and the interface to vigorously oscillate and undergo stretching deformation, which forces the gas-liquid interface, which is already close to saturation, to be renewed and exposes a new reaction interface. 5) As the gas-liquid mixture flows through the cutting section, the protrusions mechanically cut and collide the bubbles in the gas-liquid two-phase flow, forming a periodic vortex, which increases the contact area and mass transfer coefficient between the gas and liquid phases. 6) The gas-liquid mixture flows out from the outlet section and enters the next process.

10. The method for enhancing carbon dioxide absorption according to claim 9, characterized in that, Steps 2)-5) are performed sequentially in each reaction module, so that the carbon dioxide absorption process undergoes multiple cycles of "compression-stabilization-expansion-segmentation" to enhance the process.

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