CO2 enhanced desorption device and method based on hydrogen microbubbles
By using a hydrogen microbubble-enhanced desorption device and method, the problem of low energy utilization in the traditional CO2 capture-utilization pathway has been solved, achieving a reduction in CO2 desorption temperature and direct preparation of mixed gas, thereby improving system energy efficiency and economy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUANENG CLEAN ENERGY RES INST
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-12
AI Technical Summary
Existing CO2 capture-and-use pathways suffer from low energy utilization, especially in the 'purification before mixing' mode, which leads to reduced system energy efficiency and difficulty in improving economics.
A CO2 enhanced desorption device based on hydrogen microbubbles is adopted. Green hydrogen prepared from renewable energy is converted into microbubbles through a microbubble generator, which enhances turbulence and reduces the partial pressure of CO2 in the gas phase, promotes the mass transfer driving force of CO2 from the liquid phase to the gas phase, and realizes the energy-efficient utilization of the CO2 desorption process.
Without reducing CO2 production, the desorption temperature is significantly lowered, the system energy efficiency is improved, and the direct preparation of H2/CO2 mixtures is achieved, adapting to the needs of different CO2 catalytic conversion reactions and improving the system economy.
Smart Images
Figure CN122006414A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of carbon emission technology, specifically to a CO2 enhanced desorption device and method based on hydrogen microbubbles. Background Technology
[0002] Carbon dioxide (CO2), as one of the major greenhouse gases, has become a significant focus of global climate change research. CO2 capture, utilization, and storage (CCUS) technology is considered a key means of mitigating climate change and reducing CO2 emissions. With the advancement of global carbon neutrality goals, CCUS facilities have grown rapidly in recent years, but the problem of CO2 utilization after capture has become increasingly prominent. Although direct utilization technologies (such as CO2 enhanced oil recovery and food-grade applications) have made some progress in certain scenarios, their utilization scale accounts for less than 1% of global emissions; geological storage, while considered an important pathway for large-scale emission reduction, faces the practical dilemma of "source-sink mismatch." Converting CO2 into high-value-added fuels and chemicals (such as methanol, olefins, and synthetic fuels) has become an important future development direction.
[0003] In traditional carbon reduction pathways, carbon capture devices consume significant amounts of high-grade energy to purify CO2 from flue gas to over 99% purity. This process achieves high-purity gas by reducing system entropy. However, subsequent CO2 conversion stages (such as methanol synthesis and fuel synthesis) often require mixing CO2 with hydrogen to reform a gas mixture for further reaction. This "entropy-reducing purification followed by entropy-increasing mixing" separation-mixing model not only increases additional energy consumption but also reduces overall system energy efficiency, hindering economic viability. Summary of the Invention
[0004] The purpose of this invention is to provide a CO2 enhanced desorption device and method based on hydrogen microbubbles, which solves the technical problem of low energy utilization in the "purification before mixing" mode of CO2 capture-utilization path in the prior art.
[0005] To achieve the above objectives, one embodiment of the present invention provides a CO2 enhanced desorption device based on hydrogen microbubbles, including a desorption tower, which is connected to an absorption tower and a hydrogen production device, and a CO2 catalytic conversion device is also connected to the top of the desorption tower. The desorption tower is equipped with a microbubble generator, which is located at the bottom of the desorption tower and connected to the hydrogen production unit.
[0006] In one preferred embodiment of the present invention, the absorption tower is connected to a liquid exchanger for lean and rich liquids, and the liquid exchanger for lean and rich liquids is connected to the desorption tower.
[0007] In one preferred embodiment of the present invention, a double-layer porous distributor is provided inside the desorption tower, and the double-layer porous distributor is located above the microbubble generator.
[0008] In one preferred embodiment of the present invention, both the upper and lower ends of the desorption tower are connected to the absorption tower.
[0009] In one preferred embodiment of the present invention, the desorption tower is provided with a guide plate and packing.
[0010] In one preferred embodiment of the present invention, the desorption tower is connected to a reboiler, one end of which is connected to a guide plate.
[0011] In one preferred embodiment of the present invention, the hydrogen production device is equipped with a flow controller.
[0012] This invention also discloses a CO2 enhanced desorption method based on hydrogen microbubbles, implemented using the aforementioned CO2 enhanced desorption device based on hydrogen microbubbles, comprising the following steps: The CO2-rich solution in the absorption tower enters the desorption tower; The microbubble generator converts the hydrogen produced by the hydrogen production device into hydrogen microbubbles. CO2-rich solutions promote CO2 desorption under the action of hydrogen microbubbles; The H2 and CO2 mixture is fed into the CO2 catalytic converter in a specific ratio.
[0013] The process of promoting CO2 desorption by the CO2-rich solution under the action of hydrogen microbubbles includes: the CO2-rich solution heated by the reboiler comes into full contact with hydrogen microbubbles in the bottom of the stripping column to promote CO2 desorption.
[0014] One preferred embodiment of the present invention is that CO2 desorption is promoted by the action of hydrogen microbubbles in CO2-rich liquid. This includes: during the CO2 desorption process, the mass transfer driving force of CO2 from the liquid phase to the gas phase is enhanced by changing the partial pressure of CO2 in the gas phase. That is, during the CO2 desorption process, H2 microbubbles enhance heat transfer by increasing solution turbulence on the one hand, and enhance the mass transfer driving force of CO2 from the liquid phase to the gas phase by reducing the partial pressure of CO2 in the gas phase on the other hand.
[0015] In one preferred embodiment of the present invention, the diameter of the hydrogen microbubbles is 100µm-500µm.
[0016] In summary, the beneficial effects of the present invention are as follows: 1. The present invention is a CO2 enhanced desorption device based on hydrogen microbubbles. It breaks green hydrogen prepared from renewable energy into microbubbles through a microbubble generator, which significantly increases the turbulence at the bottom of the desorption tower, thereby accelerating the desorption rate of CO2 from the rich liquid.
[0017] 2. In the CO2 enhanced desorption method based on hydrogen microbubbles of the present invention, after the H2 microbubbles enter the desorption tower, they reduce the partial pressure of CO2 in the gas phase, break the mass transfer balance of CO2 desorption, and enhance the driving force of CO2 mass transfer from the liquid phase to the gas phase.
[0018] 3. The present invention, based on a hydrogen microbubble-based CO2 enhanced desorption device and method, overcomes the energy efficiency bottleneck of traditional carbon capture-conversion systems through the synergistic effect of microbubble turbulence enhancement and H2 partial pressure regulation. Without reducing CO2 production, it achieves a significant reduction in CO2 desorption temperature and direct preparation of H2 / CO2 mixture, thereby realizing efficient energy utilization and improved system economy.
[0019] 4. The present invention, based on a hydrogen microbubble-based CO2 enhanced desorption device and method, breaks the traditional CO2 capture-utilization path of "purification before mixing". It couples the carbon capture device with a renewable hydrogen production device, and uses H2 generated by hydrogen production devices using renewable energy sources such as photovoltaic and wind power to convert it into microbubbles and inject it into the desorption tower to enhance the CO2 desorption process.
[0020] 5. The present invention provides a CO2 enhanced desorption device based on hydrogen microbubbles. By precisely adjusting the flow rate of H2 injected into the desorption tower through a flow controller, the molar ratio of H2 / CO2 in the gas phase of the desorption tower can be flexibly controlled to meet the needs of different CO2 catalytic conversion reactions.
[0021] Other features and advantages of the invention will be set forth in the description which follows, 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 will be apparent from the effects described in the description and the accompanying drawings. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the CO2 enhanced desorption device based on hydrogen microbubbles in an embodiment of the present invention; Figure 2 This is a schematic flowchart of the CO2 enhanced desorption method based on hydrogen microbubbles in an embodiment of the present invention.
[0023] Among them, 1-desorption tower, 2-absorption tower, 3-microbubble generator, 4-double-layer porous distributor, 5-baffle plate, 6-packing, 7-reboiler, 8-CO2 catalytic conversion unit, and 9-hydrogen production unit. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] This invention provides a CO2 enhanced desorption device based on hydrogen microbubbles, comprising a desorption tower 1, which is connected to an absorption tower 2 and a hydrogen production device 9. The absorption tower 2 is used to convert combustion flue gas into CO2-rich liquid. Furthermore, the absorption tower 2 has a flue gas inlet, through which the combustion flue gas enters the absorption tower 2 and is converted into CO2-rich liquid, which is then transported to the desorption tower 1. The hydrogen production device 9 is used to produce hydrogen using renewable energy sources such as photovoltaic and wind power.
[0026] The top of the desorption tower 1 is also connected to a CO2 catalytic conversion unit 8, which is used to convert the H2 and CO2 mixture into chemicals such as methanol. Furthermore, the top of the desorption tower 1 has a gas outlet, through which the H2 and CO2 mixture inside the desorption tower 1 enters the CO2 catalytic conversion unit 8.
[0027] A microbubble generator 3 is installed inside the desorption tower 1. The microbubble generator 3 is located at the bottom of the desorption tower 1 and is connected to the hydrogen production unit 9. The hydrogen produced by the hydrogen production unit 9 is delivered to the microbubble generator 3, which converts the hydrogen into hydrogen microbubbles. Furthermore, the microbubble generator 3 is a Venturi tube type generator, which breaks the hydrogen into hydrogen microbubbles with a diameter of 100μm-500μm; preferably, the diameter of the hydrogen microbubbles is 200μm-300μm.
[0028] Preferably, the microbubble generator 3 is also equipped with a flow controller, which is used to adjust the number and size of the generated hydrogen microbubbles.
[0029] Preferably, the absorption tower 2 is connected to a lean-rich liquor exchanger, which is connected to the desorption tower 1. The CO2-rich liquor generated in the absorption tower 2 enters the desorption tower 1 after passing through the lean-rich liquor exchanger.
[0030] Furthermore, the desorption tower 1 is equipped with a double-layer porous distributor 4, located above the microbubble generator 3. The double-layer porous distributor 4 ensures uniform dispersion of hydrogen microbubbles; preferably, the pore size of the double-layer porous distributor 4 is 0.5mm-1mm. The desorption tower 1 also contains a flow guide plate 5 and a packing layer 6. The flow guide plate 5 enhances turbulence (Reynolds number Re > 10). 4 This significantly increases the liquid phase mass transfer coefficient by more than 40%.
[0031] Furthermore, the desorption tower 1 is also connected to a reboiler 7, one end of which is connected to a guide plate 5. The reboiler 7 is used to heat the CO2-rich liquid fed into the desorption tower 1. The CO2-rich liquid fed into the desorption tower 1 enters from the top of the desorption tower 1 and falls onto the guide plate 5 under the action of gravity through the packing 6. Under the action of the guide plate 5, it enters the reboiler 7 for heating treatment. The heated liquid and gas are then returned to the desorption tower 1.
[0032] Furthermore, both the upper and lower ends of the desorption tower 1 are connected to the absorption tower 2. The CO2-rich liquid generated in the absorption tower 2 enters the desorption tower 1 from the upper end of the desorption tower 1, and the liquid that is heated by the reboiler 7 and then refluxes back to the desorption tower 1 enters the absorption tower 2 through the bottom end of the desorption tower 1.
[0033] Furthermore, the hydrogen production unit 9 is equipped with a flow controller, which is used to precisely adjust the flow rate of H2 injected into the desorption tower 1, thereby flexibly controlling the molar ratio of H2 / CO2 in the gas phase of the desorption tower 1, reducing the partial pressure of CO2 in the gas phase to the target value, thereby reducing the desorption temperature, obtaining the required ratio of H2 and CO2 mixture, and thus adapting to the needs of different CO2 catalytic conversion reactions.
[0034] Working principle: The CO2 enhanced desorption device based on hydrogen microbubbles breaks down the green hydrogen produced from renewable energy into microbubbles through the microbubble generator 3, which significantly increases the turbulence at the bottom of the desorption tower 1, thereby accelerating the desorption rate of CO2 from the rich liquid. At the same time, the generated hydrogen microbubbles reduce the partial pressure of CO2 in the gas phase, break the mass transfer balance of CO2 desorption, and enhance the driving force of CO2 mass transfer from the liquid phase to the gas phase.
[0035] Working process: After combustion, the flue gas enters the absorption tower 2 through the flue gas inlet and is converted into CO2-rich liquid. After passing through the lean-rich liquid exchanger, the generated CO2-rich liquid enters the desorption tower 1 from the top. At the same time, the hydrogen production unit 9 is turned on to produce hydrogen. The generated hydrogen is sent to the microbubble generator 3, where it is converted into hydrogen microbubbles. The hydrogen microbubbles rise, while the CO2-rich liquid falls downward through the packing 6 onto the guide plate 5. Under the action of the guide plate 5, it enters the reboiler 7 for heating treatment. The heated liquid and gas are returned to the desorption tower 1. At this time, the H2 and CO2 mixture at the top of the desorption tower 1 enters the CO2 catalytic conversion unit 8 and is converted into chemicals such as methanol. The liquid flows back to the absorption tower 2 through the bottom of the desorption tower 1.
[0036] This invention also discloses a CO2 enhanced desorption method based on hydrogen microbubbles, implemented using the aforementioned CO2 enhanced desorption device based on hydrogen microbubbles, as follows: Figure 2 As shown, it includes the following steps: Step (1): The CO2-rich liquid in the absorption tower 2 enters the desorption tower 1; specifically, the flue gas after combustion enters the interior of the absorption tower 2 through the flue gas inlet and is converted into CO2-rich liquid. After passing through the lean-rich liquid exchanger, the generated CO2-rich liquid enters the desorption tower 1 from the top. Step (2): The microbubble generator 3 converts the hydrogen produced by the hydrogen production device 9 into hydrogen microbubbles; specifically, the hydrogen production device 9 uses renewable energy sources such as photovoltaic and wind power to produce hydrogen, and the generated hydrogen is transported to the microbubble generator 3, which converts the hydrogen into hydrogen microbubbles under the action of the microbubble generator 3. Step (3): CO2-rich liquid is promoted to desorb CO2 under the action of hydrogen microbubbles; preferably, the CO2-rich liquid heated by the reboiler is in full contact with hydrogen microbubbles in the bottom of the desorption tower 1 to promote CO2 desorption; specifically, the hydrogen microbubbles rise upward and the CO2-rich liquid falls downward. The hydrogen microbubbles increase the turbulence to enhance the desorption of CO2-rich liquid in the desorption tower 1 and promote CO2 desorption. The desorbed CO2 is mixed with H2 and enters the CO2 catalytic conversion device 8 for conversion; further, during the CO2 desorption process, the hydrogen microbubbles will reduce the partial pressure of CO2 in the gas phase, thereby enhancing the mass transfer driving force of CO2 from the liquid phase to the gas phase. That is, during the CO2 desorption process, the H2 microbubbles enhance the heat transfer by increasing the turbulence of the solution on the one hand, and enhance the mass transfer driving force of CO2 from the liquid phase to the gas phase on the other hand by reducing the partial pressure of CO2 in the gas phase.
[0037] Furthermore, the diameter of the hydrogen microbubbles is 100µm-500µm; preferably, the diameter of the hydrogen microbubbles is 200µm-300µm.
[0038] Step (4): The H2 and CO2 mixture enters the CO2 catalytic conversion unit 8 in a certain proportion; specifically: the H2 and CO2 mixture enters the CO2 catalytic conversion unit 8 in the required proportion for conversion into chemicals such as methanol.
[0039] Table 1 shows a comparison between the CO2 enhanced desorption method based on hydrogen microbubbles of this invention and traditional processes.
[0040] Table 1: Comparison of the process of this invention with the traditional process
[0041] As can be seen from Table 1, the process of the present invention has significantly lower desorption temperature and CO2 partial pressure at the top of desorption tower 1 than the traditional process. Furthermore, the process of the present invention directly mixes H2 according to demand, without the need for desorption and then mixing with pure CO2, thus achieving efficient energy utilization and improved system economy.
[0042] This invention relates to a CO2-enhanced desorption method based on hydrogen microbubbles. A microbubble generator 3 converts H2 produced from renewable energy hydrogen production into 100-500 μm microbubbles, which are then injected into a desorption tower 1. This increases turbulence and enhances the desorption of CO2-rich liquid at the bottom of the reactor. Furthermore, the H2 entering the desorption tower 1 further reduces the partial pressure of CO2 in the gas phase, increasing the mass transfer driving force of the CO2 desorption process. This significantly reduces the desorption temperature to 100℃-110℃ without changing the CO2 output. The resulting H2 / CO2 mixture can be directly used in downstream CO2 conversion processes. Simultaneously, by adjusting the H2 bubble flow rate, the H2 / CO2 ratio can be finely adjusted, making it suitable for various CO2 catalytic conversion devices.
[0043] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A CO2 enhanced desorption device based on hydrogen microbubbles, characterized in that: It includes a desorption tower, which is connected to an absorption tower and a hydrogen production device, and a CO2 catalytic conversion device is also connected to the top of the desorption tower; The desorption tower is equipped with a microbubble generator, which is located at the bottom of the desorption tower and is connected to the hydrogen production device.
2. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 1, characterized in that: The absorption tower is connected to a lean-rich liquid exchanger, which is connected to the desorption tower.
3. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 1, characterized in that: The desorption tower is equipped with a double-layer porous distributor, which is located above the microbubble generator.
4. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 1, characterized in that: The upper and lower ends of the desorption tower are both connected to the absorption tower.
5. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 1, characterized in that: The desorption tower is equipped with guide plates and packing.
6. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 5, characterized in that: The desorption tower is connected to a reboiler, one end of which is connected to a guide plate.
7. The CO2 enhanced desorption device based on hydrogen microbubbles as described in claim 1, characterized in that: The hydrogen production device is equipped with a flow control meter.
8. A CO2 enhanced desorption method based on hydrogen microbubbles, implemented using a CO2 enhanced desorption device based on hydrogen microbubbles as described in any one of claims 1-7, characterized in that, Includes the following steps: The CO2-rich solution in the absorption tower enters the desorption tower; The microbubble generator converts the hydrogen produced by the hydrogen production device into hydrogen microbubbles. CO2-rich solutions promote CO2 desorption under the action of hydrogen microbubbles; The H2 and CO2 mixture is fed into the CO2 catalytic converter in a specific ratio.
9. The CO2 enhanced desorption method based on hydrogen microbubbles as described in claim 8, characterized in that: The CO2-rich liquid promotes CO2 desorption under the action of hydrogen microbubbles by: during the CO2 desorption process, by changing the partial pressure of CO2 in the gas phase, the mass transfer driving force of CO2 from the liquid phase to the gas phase is enhanced.
10. The CO2 enhanced desorption method based on hydrogen microbubbles as described in claim 8, characterized in that: The diameter of the hydrogen microbubbles is 100µm-500µm.