CO2 capture device using membrane absorption intensified microchannel reactor gas-liquid two-phase mass transfer
By introducing a hydrophobic and breathable membrane into the microchannel reactor as a physical barrier for the gas-liquid two-phase flow, the contact area between the gas and liquid phases is enhanced, thus solving the problem of insufficient CO2 capture efficiency in the microchannel reactor and achieving a highly efficient CO2 capture effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2024-01-10
- Publication Date
- 2026-07-24
AI Technical Summary
Existing microchannel reactors have not yet met the requirements for industrial applications in terms of CO2 capture efficiency, and there is a need to improve mass transfer efficiency.
By combining a microchannel reactor with a membrane contactor, a hydrophobic and breathable membrane is used as a physical barrier for the gas-liquid two-phase flow within the microchannel. The hydrophobic and breathable membrane allows CO2 in the gas phase to diffuse into the liquid phase, where it undergoes chemical absorption with the liquid phase reactants, thereby enhancing the gas-liquid two-phase contact area and mass transfer efficiency.
This effectively improved the mass transfer performance of the CO2 capture device, enabling long-term stable operation and efficient CO2 capture.
Smart Images
Figure CN117899622B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microchannel reactor technology, and more specifically to a CO2 capture device that utilizes membrane absorption to enhance gas-liquid two-phase mass transfer in a microchannel reactor. Background Technology
[0002] Research on how to control greenhouse gas emissions, as well as the centralized separation, capture, storage, and even utilization of these greenhouse gases, has become a hot topic of concern in the scientific community. As the most important greenhouse gas, CO2 capture-storage (CCS) and capture-and-utilize (CUU) technologies largely determine whether total greenhouse gas emissions can be effectively controlled globally, thereby improving environmental quality. Therefore, carbon capture technology has significant practical implications and urgency.
[0003] To reduce CO2 emissions from the combustion of fossil fuels such as coal, oil, and natural gas through carbon capture and storage (CCS) or carbon capture and utilization (CUU) technologies, the scientific community believes that CO2 emissions can be reduced by separating CO2 from mixed gases (such as power plant flue gas). Taking power plants as an example, CO2 capture technologies can be divided into pre-combustion capture, oxygen-enriched combustion, and post-combustion capture, depending on the capture location and the sequence of combustion processes. Post-combustion capture technology involves separating and recovering CO2 from the flue gas produced after fuel combustion. This requires first passing the flue gas through a cyclone separator for dust removal, then desulfurizing and denitrifying the flue gas by spraying lime water, and finally capturing the CO2 using capture materials. Depending on the separation method, post-combustion CO2 capture can be mainly divided into: absorption, solid adsorption, membrane separation, and low-temperature phase separation.
[0004] Absorption methods can be divided into physical absorption, which relies on dissolution, and chemical absorption, which relies on acid-base neutralization. Physical absorption refers to the absorption and separation of target components based on the different solubilities of various components in the absorbent under pressure. No chemical reaction occurs during this process, and the absorbent can be regenerated by reducing the pressure, resulting in relatively low regeneration energy consumption. Physical absorption requires low temperature and high pressure conditions. When absorbing CO2, water and polyesters are commonly chosen as absorbents; commonly used absorbents include polyethylene glycol, dimethyl methacrylate (DMCA), propylene carbonate, acrylate, and methanol. The solubility of CO2 in a solvent is significantly affected by pressure; therefore, the separation and capture of CO2 can be achieved by changing the external pressure. Chemical absorption separates CO2 from flue gas through a chemical reaction between the absorbent and CO2. Weakly basic organic amine compounds or alkaline substances are used as absorbents to react with the acidic CO2 gas in the flue gas, producing unstable intermediate products that separate CO2 from the mixture. Currently, the most widely used and technologically mature CO2 absorption method in industry is the tower chemical absorption method.
[0005] In CO2 capture technology research, common laboratory devices include microchannel reactors, microfalling film reactors, and microgrid reactors. However, the CO2 capture efficiency of existing microchannel reactors for CO2 capture is still some distance from that of industrial applications, and further improvements in mass transfer efficiency are needed to adapt to industrial production applications. Summary of the Invention
[0006] The purpose of this invention is to address the above-mentioned problems by providing a CO2 capture device that utilizes membrane absorption to enhance gas-liquid two-phase mass transfer in a microchannel reactor.
[0007] To achieve its objective, the present invention employs the following technical solution:
[0008] A CO2 capture device that utilizes membrane absorption to enhance gas-liquid two-phase mass transfer in a microchannel reactor includes a CO2 supply chamber, an air-passing plate, a hydrophobic and breathable membrane, and a microchannel plate arranged sequentially from top to bottom.
[0009] The CO2 supply chamber includes a gas-containing chamber, which is closed at the top and open at the bottom. A folded edge is provided along the circumferential direction of the bottom end of the gas-containing chamber, and an air inlet and an air outlet are provided on the gas-containing chamber.
[0010] The air passage plate is provided with multiple parallel hollow channels for gas to pass through;
[0011] The hydrophobic and breathable membrane is made of a hydrophobic material and allows CO2 gas to permeate through, maintaining the flow characteristics of the microchannel.
[0012] The microchannel plate has a head end groove and a tail end groove, respectively. Multiple parallel microchannels are arranged between the head end groove and the tail end groove. The two ends of each microchannel are connected to the head end groove and the tail end groove, respectively. A vertically extending head end channel and a vertical tail end channel are respectively arranged in the middle of the head end groove and the tail end groove. The interior of the microchannel plate has a horizontally extending head end internal channel, a side internal channel, and a tail end internal channel. A head end inlet is formed on the side wall of the head end of the microchannel plate. One end of the head end internal channel is connected to the head end groove. One end is an inlet, and the other end is connected to the bottom end of the vertical channel at the head end; a tail end outlet is provided on one side wall of the tail end of the microchannel plate, one end of the internal channel at the tail end is connected to the tail end outlet, and the other end is connected to the bottom end of the vertical channel at the tail end; a central vertical channel extending downward is provided near the head end of the microchannel, and a side inlet is provided on one side wall of both sides of the microchannel plate, one end of the internal channel of the side is connected to the side inlet, and the other end is connected to the bottom end of the central vertical channel, and multiple central vertical channels are connected in parallel with the internal channel of the side;
[0013] The position, shape, and size of the perforated channels on the air passage plate match the microchannels on the microchannel plate. Each perforated channel corresponds to a microchannel, allowing CO2 gas in the CO2 supply chamber to reach the hydrophobic and breathable membrane through the perforated channels, and then permeate through the hydrophobic and breathable membrane into the microchannel to react with the liquid phase reactants in the microchannel.
[0014] Preferably, the CO2 capture device further includes a membrane frame located directly below the hydrophobic and breathable membrane for supporting the membrane; the microchannel plate is provided with a membrane frame groove for placing the membrane frame.
[0015] Preferably, the CO2 capture device further includes a sealing ring, and the microchannel plate is provided with a sealing ring groove for placing the sealing ring.
[0016] Preferably, the CO2 capture device is assembled using screw holes and bolts.
[0017] Preferably, the CO2 supply chamber has multiple screw holes around its folded edge, air passage plate, and microchannel plate.
[0018] Preferably, the hydrophobic and breathable membrane is made of polytetrafluoroethylene.
[0019] Preferably, the CO2 capture device is rectangular in shape.
[0020] Preferably, the head inlet is used to introduce liquid-phase reactants, and the side inlet is used to introduce CO2-containing gas.
[0021] Preferably, the microchannels, head grooves, and tail grooves are etched on the upper surface of the microchannel plate.
[0022] The beneficial effects of this invention are as follows: This invention combines a microchannel reactor with a membrane contactor absorption method. It utilizes a hydrophobic and breathable membrane as a physical barrier between the gas-liquid two-phase flow within parallel-arranged microchannels and the additional gas component in the gas supply chamber. The gas phase diffuses through the hydrophobic and breathable membrane to the liquid phase, allowing the gas and liquid phases to contact and undergo chemical absorption without mixing. Mass transfer between the gas and liquid is achieved through diffusion-chemical absorption, effectively solving the problems encountered in dispersed gas-liquid contact processes. Each microchannel serves as a reaction site. Based on the traditional microchannel reactor, the introduction of additional CO2 component gas as a gaseous reactant increases the gas-liquid two-phase contact area, effectively enhancing mass transfer, improving reactor performance, and enabling long-term stable operation. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the exploded structure of the CO2 capture device of the present invention;
[0024] Figure 2 This is a schematic diagram of the assembly structure of the CO2 capture device of the present invention;
[0025] Figure 3 This is a schematic diagram of the air passage plate;
[0026] Figure 4 yes Figure 1 A top view of the microchannel plate in the image;
[0027] Figure 5 yes Figure 4 Enlarged structural diagram of structure A in the middle;
[0028] Figure 6 yes Figure 1 A perspective view of the microchannel plate in the image;
[0029] Figure 7 This is a schematic diagram showing the connection relationship between the microchannels, the central vertical channel, and the side internal channels of a microchannel plate.
[0030] Figure 8 yes Figure 1 A schematic diagram of the CO2 supply chamber in the diagram;
[0031] The elements or structures indicated by the reference numerals in the attached drawings are:
[0032] CO2 supply chamber 1, gas containing chamber 11, folded edge 12, air inlet 13, air outlet 14;
[0033] 2. Air passage plate; 21. Hollowed-out channel;
[0034] 3. Hydrophobic and breathable membrane;
[0035] Microchannel plate 4, head end groove 41, tail end groove 42, microchannel 43, head end vertical channel 44, tail end vertical channel 45, head end internal channel 46, side internal channel 47, tail end internal channel 48, head end inlet 49, tail end outlet 410, middle vertical channel 411, side inlet 412, membrane frame groove 413, sealing ring groove 414;
[0036] 5. Membrane frame; 6. Sealing ring. Detailed Implementation
[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, but this does not limit the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0038] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.
[0039] Example 1
[0040] like Figures 1-8 The CO2 capture device shown utilizes membrane absorption to enhance gas-liquid two-phase mass transfer in a microchannel reactor. It mainly consists of a CO2 supply chamber 1, a gas-passing plate 2, a hydrophobic and breathable membrane 3, and a microchannel plate 4, arranged sequentially from top to bottom. The CO2 supply chamber 1 includes a gas-containing chamber 11, which is closed at the top and open at the bottom. A horizontally extending outward-facing folded edge 12 is provided along the bottom circumference of the gas-containing chamber 11 (the folded edge 12 can have screw holes and also serves as a cover plate for easy device assembly). The gas-containing chamber 11 has an inlet 13 and an outlet 14. The gas-passing plate 2 has multiple parallel perforated channels 21 for gas passage. The hydrophobic and breathable membrane 3 is made of a hydrophobic material and allows CO2 gas to permeate through it.
[0041] The microchannel plate 4 has a head end groove 41 and a tail end groove 42 at its head and tail ends, respectively. Multiple parallel microchannels 43 are arranged between the head end groove 41 and the tail end groove 42. The two ends of each microchannel 43 are connected to the head end groove 41 and the tail end groove 42, respectively. A vertically extending head end channel 44 and a vertical tail end channel 45 are respectively arranged between the head end groove 41 and the tail end groove 42. The microchannel plate 4 has a horizontally extending head end internal channel 46, a side internal channel 47, and a tail end internal channel 48. A head end inlet 49 is opened on the side wall of the head end of the microchannel plate 4. One end of the head end internal channel 46 is connected to… The connector end inlet 49 is connected to the bottom end of the head end vertical channel 44 at the other end; the tail end plate 4 has a tail end outlet 410 on one side wall of the tail end, one end of the tail end internal channel 48 is connected to the tail end outlet 410, and the other end is connected to the bottom end of the tail end vertical channel 45; the microchannel 43 has a downwardly extending central vertical channel 411 near the head end, and the side inlets 412 are opened on one side wall of both sides of the microchannel plate 4, one end of the side internal channel 47 is connected to the side inlet 412, and the other end is connected to the bottom end of the central vertical channel 411, and multiple central vertical channels 411 are connected in parallel with the side internal channels 47;
[0042] The position, shape and size of the perforated channel 21 on the air passage plate 2 match the microchannel 43 on the microchannel plate 4. Each perforated channel 21 corresponds to a microchannel 43, so that the CO2 gas in the CO2 supply chamber 1 reaches the hydrophobic and breathable membrane 3 through the perforated channel 21, and then permeates through the hydrophobic and breathable membrane 3 into the microchannel 43 to react with the liquid phase reactants in the microchannel 43.
[0043] The working principle of the CO2 capture device of the present invention is as follows:
[0044] This invention relates to a device for CO2 chemical adsorption and capture. A liquid reactant for CO2 absorption is introduced through the head end inlet 49. The liquid flows from the head end internal channel 46 into the head end groove 41, and then through the connection between the head end groove 41 and multiple parallel microchannels 43 into each microchannel 43. A CO2-containing mixed gas is divided into two paths: one path is introduced through the side inlet 412, flows and splits in the side internal channel 47 into each central vertical channel 411, and then enters the microchannel 43 to react with the liquid reactant therein; the other path enters the CO2 supply chamber 1 through the inlet 13, passes downward through the perforated channel 21 of the air-permeable plate 2, permeates through the hydrophobic and breathable membrane 3, and then reaches the microchannel 43 to react with the liquid reactant therein. While a CO2-containing mixed gas is continuously introduced into the CO2 supply chamber 1, the outlet 14 remains open. The CO2 gas flows downwards, while other gases in the mixed gas flow out from the outlet 14, achieving separation of the mixed gas. The gas-liquid two-phase reactants and products flow in the microchannel 43, reach the tail end groove 42, then enter the tail end internal channel 48, and finally flow out from the tail end outlet 410, leaving this device to enter the next device for the next processing step. The liquid phase reactants can be various adsorbents reported in the prior art, such as ethanolamine solution.
[0045] The device of this invention is configured with a CO2 supply chamber 1, an air-passing plate 2, and a hydrophobic and permeable membrane 3. The hydrophobic and permeable membrane 3 allows only gas to pass through, but not liquid. This invention utilizes the hydrophobic and permeable membrane as a physical barrier between the gas-liquid two-phase flow in the parallel-arranged microchannels and the additional gas components in the supply chamber. Based on the traditional microchannel reactor, it introduces additional CO2 component gas as a gaseous reactant, further increasing the gas-liquid two-phase contact area, which can effectively enhance mass transfer, improve reactor performance, and achieve long-term stable operation.
[0046] In some embodiments, the CO2 capture device of the present invention further includes a membrane frame 5, which is located directly below the hydrophobic and breathable membrane 3 and is used to support the hydrophobic and breathable membrane 3; the microchannel plate 4 is provided with a membrane frame groove 413 for placing the membrane frame 5.
[0047] In some embodiments, the CO2 capture device of the present invention further includes a sealing ring 6, and a sealing ring groove 414 for placing the sealing ring 6 is provided on the microchannel plate 4. The arrangement of the membrane frame 5 and the sealing ring 6 improves the overall sealing performance of the device.
[0048] In some embodiments, the CO2 capture device of the present invention is assembled using screw bolts. Preferably, the folded edge 12 of the CO2 supply chamber 1, the gas passage plate 2, and the microchannel plate 4 are provided with multiple screw holes around their perimeters, facilitating assembly.
[0049] In some embodiments, the hydrophobic and breathable membrane 3 of the CO2 capture device of the present invention is made of polytetrafluoroethylene.
[0050] In some embodiments, the CO2 capture device of the present invention is rectangular, which facilitates manufacturing and assembly.
[0051] In some embodiments, the head inlet 49 of the CO2 capture device of the present invention is used to introduce liquid-phase reactants, and the side inlet 412 is used to introduce CO2-containing gas. Alternatively, the process can be reversed, with CO2-containing gas introduced through the head inlet 49 and liquid-phase reactants introduced through the side inlet 412. Both methods enable the device to operate stably for extended periods and capture CO2 efficiently.
[0052] In some embodiments, the microchannel 43, the head groove 41, and the tail groove 42 are etched on the upper surface of the microchannel plate 4, making them easy to manufacture.
Claims
1. A CO2 capture device that utilizes membrane absorption to enhance gas-liquid two-phase mass transfer in a microchannel reactor, characterized in that: It includes a CO2 supply chamber (1), an air passage plate (2), a hydrophobic and breathable membrane (3), and a microchannel plate (4) arranged from top to bottom. The CO2 supply chamber (1) includes a gas-containing chamber (11), which is closed at the top and open at the bottom. A folded edge (12) is provided around the bottom of the gas-containing chamber (11), and an air inlet (13) and an air outlet (14) are provided on the gas-containing chamber (11). The air passage plate (2) is provided with multiple parallel hollow channels (21) for gas to pass through; The hydrophobic and breathable membrane (3) is made of a hydrophobic material and allows CO2 gas to permeate through it; The microchannel plate (4) has a head end groove (41) and a tail end groove (42) at its head end and tail end, respectively. Multiple parallel microchannels (43) are provided between the head end groove (41) and the tail end groove (42). The two ends of the microchannels (43) are connected to the head end groove (41) and the tail end groove (42), respectively. The head end vertical channel (44) and the tail end vertical channel (45) extending vertically downward are provided in the middle of the head end groove (41) and the tail end groove (42), respectively. The interior of the microchannel plate (4) has a horizontally extending head end internal channel (46), a side internal channel (47) and a tail end internal channel (48). A head end inlet (49) is provided on the side wall of the head end of the microchannel plate (4) for introducing liquid phase reactants. One end of the head end internal channel (46) is connected to The head end inlet (49) is connected to the bottom end of the head end vertical channel (44) at the other end; a tail end outlet (410) is provided on the side wall of the tail end of the microchannel plate (4), one end of the tail end internal channel (48) is connected to the tail end outlet (410), and the other end is connected to the bottom end of the tail end vertical channel (45); a central vertical channel (411) extending vertically downward is provided near the head end of the microchannel (43), and a side inlet (412) for introducing CO2 component gas is provided on the side wall of both sides of the microchannel plate (4), one end of the side internal channel (47) is connected to the side inlet (412), and the other end is connected to the bottom end of the central vertical channel (411), and multiple central vertical channels (411) are connected in parallel with the side internal channels (47); The position, shape and size of the perforated channel (21) on the air passage plate (2) match the microchannel (43) on the microchannel plate (4). Each perforated channel (21) corresponds to a microchannel (43), so that the CO2 gas in the CO2 supply chamber (1) reaches the hydrophobic and breathable membrane (3) through the perforated channel (21), and then permeates through the hydrophobic and breathable membrane (3) into the microchannel (43) to react with the liquid phase reactants in the microchannel (43).
2. The CO2 capture device according to claim 1, characterized in that: It also includes a membrane frame (5), which is located directly below the hydrophobic and breathable membrane (3) and is used to support the hydrophobic and breathable membrane (3); the microchannel plate (4) is provided with a membrane frame groove (413) for placing the membrane frame (5).
3. The CO2 capture device according to claim 1, characterized in that: It also includes a sealing ring (6), and the microchannel plate (4) is provided with a sealing ring groove (414) for placing the sealing ring (6).
4. The CO2 capture device according to claim 1, characterized in that: The CO2 capture device is assembled using screw holes and bolts.
5. The CO2 capture device according to claim 4, characterized in that: The CO2 supply chamber (1) has multiple screw holes around its folded edge (12), air passage plate (2), and microchannel plate (4).
6. The CO2 capture device according to claim 1, characterized in that: The hydrophobic and breathable membrane (3) is made of polytetrafluoroethylene.
7. The CO2 capture device according to claim 1, characterized in that: The CO2 capture device is rectangular in shape.
8. The CO2 capture device according to claim 1, characterized in that: The microchannel (43), the head groove (41) and the tail groove (42) are engraved on the upper surface of the microchannel plate (4).