Micro-droplet gas rotational flow absorption type carbon dioxide capturing and converting system and method

Abstract

The invention relates to the technical field of carbon dioxide capture and conversion, in particular to a micro-droplet gas rotational flow absorption type carbon dioxide capture and conversion system and a use method. Comprising a micro-droplet spraying mechanism, a CO2 input mechanism, a spiral rotational flow absorption mechanism, a biological conversion mechanism, a PLC control platform, a gas mixing chamber and a liquid collection device, an enrichment liquid spiral pipe with high shear and centrifugal atomization effects is innovatively designed, and a 10 m-level micro-droplet generation system is combined, so that CO2 and absorption liquid are subjected to sub-millisecond-level efficient reaction, and the CO2 absorption efficiency is improved. According to the method, the initial trapping efficiency is higher than 90%, the biotransformation mechanism is arranged, CO2 is directly used as an algae photosynthetic carbon source for feeding, biotransformation of CO2 is achieved, the carbon resource utilization efficiency of the system is remarkably improved, and the biotransformation mechanism achieves CO2 absorption and transformation and releases oxygen at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture and conversion, and in particular to a micro-droplet gas cyclone absorption type carbon dioxide capture and conversion system and a method of use. Background Art

[0002] Carbon dioxide, the most significant greenhouse gas, continues to rise in atmospheric concentrations, reaching 149% of pre-industrial levels. This increase is primarily attributed to industrial emissions from fossil fuel use and cement production. Currently, carbon dioxide is the most significant anthropogenic greenhouse gas, contributing 82% of radiative emissions. Fossil fuels still dominate the global energy mix, accounting for over 80%. According to multiple forecasts, fossil fuels will continue to dominate the energy market for decades to come, and by 2050, their share is projected to reach approximately 50%. After years of development, a series of technical approaches have emerged for treating carbon dioxide waste gas, primarily including physical adsorption, membrane separation, and solvent absorption. Physical adsorption commonly uses materials such as activated carbon and zeolites, but these methods suffer from poor adsorption selectivity, low capacity, and slow reaction rates. Membrane separation utilizes the combination of gas solubility selectivity and membrane material permeability to separate CO2. However, this method places extremely high demands on membrane material performance, resulting in high membrane costs, fragile structures, and limited adaptability to complex operating conditions. Solvent absorption is currently the most widely used method, relying on chemical absorbents such as amines, alcohol amines, and ammonia water to react with CO2. Although the absorption efficiency is high, the system investment and operating energy consumption are large, which has a significant impact on the power generation efficiency of the power plant.

[0003] In general, existing CO2 capture methods generally have prominent problems such as low efficiency, high cost, and high energy consumption. The CO2 concentration of many industrial emission sources is low, and traditional capture methods are difficult to treat efficiently and economically. In addition, there is no good method for reusing CO2 after capture. The CO2 concentration purity of many industrial emission sources is limited, and traditional capture methods are difficult to treat efficiently and economically. The means of converting the value of CO2 resources after capture are also relatively limited.

[0004] In summary, there is an urgent need for a CO2 capture and conversion technology that is efficient, low-cost and highly integrated, which can adapt to industrial and environmental needs of different scales and achieve efficient utilization of CO2 and carbon neutrality. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a micro-droplet gas cyclone absorption carbon dioxide capture and conversion system and a method of use, which are used to solve the problems of low efficiency, high cost, high energy consumption, etc. of the existing CO2 capture method, as well as the problem of low reuse rate of CO2 after capture.

[0006] To solve the above problems, the technical solution of the present invention is as follows: a micro-droplet gas cyclone absorption type carbon dioxide capture and conversion system, including a micro-droplet spray mechanism for atomizing the absorption liquid, a CO2 input mechanism for adjusting the CO2 concentration, a spiral cyclone absorption mechanism for adsorbing CO2, a biological transformation mechanism for CO2 absorption, and a PLC control platform. The micro-droplet spray mechanism is connected to the CO2 input mechanism through a gas mixing chamber, the gas mixing chamber is connected to the spiral cyclone absorption mechanism, the spiral cyclone absorption mechanism is connected to the biological transformation mechanism through a liquid collection device, and the liquid collection device includes a first collection tank connected to the spiral cyclone absorption mechanism and the biological transformation mechanism through a pipeline, and a peristaltic pump arranged in the first collection tank.

[0007] Furthermore, the micro-droplet spray mechanism is a high-pressure micro-hole nozzle or an electric atomizing nozzle.

[0008] Furthermore, the CO2 input mechanism includes a gas mixer, and the gas mixer is connected to a mass flow controller.

[0009] Furthermore, the spiral cyclone absorption mechanism includes several spiral tube separators, which include a delivery pipe located in the center, and several enriched liquid spiral tubes for adsorbing CO2 are connected to the periphery of the delivery pipe. The top end of the delivery pipe is connected to the gas mixer and the tail end is the gas outlet. The top end of the enriched liquid spiral tube is connected to the upper end of the delivery pipe and the tail end is connected to the liquid collection device.

[0010] Furthermore, the inner diameter of the enrichment liquid spiral tube is 5-50 mm, the number of spiral turns is 2-20, and the cross-sectional shape is trapezoidal, triangular, circular or elliptical.

[0011] Furthermore, the gas outlet is connected to a negative pressure pump via a first gas outlet pipe, a second collection tank is provided between the first collection tank and the biotransformation mechanism, and the second collection tank is connected to the negative pressure pump via a second gas outlet pipe.

[0012] Furthermore, the biotransformation mechanism includes several photobiological reaction tanks connected to the liquid collection device, an LED simulated lighting system, and a temperature control system. The Chlorella solution is introduced into the photobiological reaction tank, and a pH monitoring and adjustment module is provided in the photobiological reaction tank.

[0013] The capture conversion method comprises the following steps: (1) The micro-droplet spray mechanism atomizes the absorption liquid into micro-droplets, and the CO2 input mechanism adjusts the CO2 waste gas into CO2-enriched gas. In the gas mixing chamber, the micro-droplets and the CO2-enriched gas are initially turbulently mixed to obtain a gas-liquid mixture; (2) The gas-liquid mixture enters the spiral tube separator under the action of a negative pressure pump to dissolve CO2 gas. The gas linear velocity is 6-20 m / s, and a CO2-enriched liquid is obtained. (3) Gas-liquid separation, CO2-enriched liquid is transported to the photobiological reactor for carbon sequestration.

[0014] Furthermore, in step (1), the particle size D50 of the microdroplets is ≤50µm, the volume fraction of the microdroplets accounts for 0.5% to 20% v / v of the gas volume, and the CO2 concentration in the CO2-enriched gas is 2–40%; Spray flow rate: 1-50 mL / min; The pH of the nebulized liquid was maintained at 7-10.

[0015] Furthermore, in step (3), the LED simulation illumination system uses a mixed illumination of red light 660nm + blue light 450nm with an intensity of 300-800μmol / m² / s; the temperature control system controls the temperature at 25-30°C; and the pH monitoring and adjustment module controls the pH at 6.8-7.5.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. An innovatively designed enrichment liquid spiral tube with high shear and centrifugal atomization effects, combined with a 50 µm-level micro-droplet generation system, enables CO2 and absorption liquid to achieve sub-millisecond efficient reaction, achieving an initial capture efficiency of >90%.

[0017] 2. Set up a bioconversion mechanism to directly feed CO2 as the photosynthetic carbon source for algae to achieve bioconversion of CO2 and significantly improve the carbon resource utilization efficiency of the system. Chlorella cultivation not only realizes CO2 absorption and conversion, but also releases oxygen and produces protein, which can be used for animal feed, vegetarian products and health products. Lipids and unsaturated fatty acids can be used to prepare biodiesel or nutritional oils. By-products can be used as fuel, chemical raw materials or nutritional supplements, ultimately achieving multi-path carbon recovery and value-added.

[0018] 3. The micro-droplet spray mechanism significantly increases the specific surface area (>10,000 cm² / mL) by designing the particle size of the absorption liquid, greatly improving the gas-liquid contact efficiency, so that more than 80% of the CO2 undergoes initial physical dissolution and partial chemical reaction before entering the spiral reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall appearance of the present invention; Figure 2 This is a schematic diagram of the connection of the spiral tube separator of the present invention; Figure 3 Schematic diagram of the spiral tube separator of the present invention.

[0020] In the figure: 1 micro-droplet spray mechanism, 2 CO2 input mechanism, 3 spiral cyclone absorption mechanism, 301 spiral reactor, 302 delivery pipe, 303 enrichment liquid spiral pipe, 304 gas outlet, 4 biotransformation mechanism, 401 photobiological reaction tank, 5 gas mixing chamber, 6 first collection tank, 7 first gas outlet pipe, 8 negative pressure pump, 9 second collection tank, 10 second gas outlet pipe. DETAILED DESCRIPTION

[0021] like Figure 1 、 Figure 2 、 Figure 3 As shown, the micro-droplet gas cyclone absorption type carbon dioxide capture and conversion system includes a micro-droplet spray mechanism 1 for atomizing the absorption liquid, a CO2 input mechanism 2 for adjusting the CO2 concentration, a spiral cyclone absorption mechanism 3 for adsorbing CO2, a biological transformation mechanism 4 for CO2 absorption, and a PLC control platform. The absorption liquid can be pure water or an alkaline solution (such as NaOH, NaHCO3, NaCO3). The micro-droplet spray mechanism 1 is connected to the CO2 input mechanism 2 through a gas mixing chamber 5, the gas mixing chamber 5 is connected to the spiral cyclone absorption mechanism 3, the spiral cyclone absorption mechanism 3 is connected to the biological transformation mechanism 4 through a liquid collecting device, and the liquid collecting device includes a first collecting tank 6 connected to the spiral cyclone absorption mechanism 3 and the biological transformation mechanism 4 through a pipeline, and a peristaltic pump arranged in the first collecting tank 6.

[0022] like Figure 2 As shown, the micro-droplet spray mechanism 1 is a high-pressure micro-pore nozzle or an electric atomizing nozzle, which atomizes the absorption liquid into micro-droplets. The particle size D50 of the micro-droplets is ≤10µm. This particle size design significantly increases the specific surface area (>10,000 cm² / mL) and greatly improves the gas-liquid contact efficiency, so that more than 80% of the CO2 undergoes preliminary physical dissolution and partial chemical reaction before entering the spiral reactor 201.

[0023] The CO2 input mechanism 2 includes a gas mixer, which is connected to a mass flow controller. The intake gas is diluted with air through the gas mixer, and the mass flow controller is used to accurately adjust the CO2 concentration to 2–40%.

[0024] like Figure 2 、 Figure 3As shown, the spiral cyclone absorption mechanism 3 includes several spiral tube separators 301, and the spiral tube separator 301 includes a delivery pipe 302 located in the center. Several enriched liquid spiral tubes 303 for adsorbing CO2 are connected to the periphery of the delivery pipe 302. The top of the delivery pipe 302 is connected to the gas mixer 5, and the tail end is a gas outlet 304. The top of the enriched liquid spiral tube 303 is connected to the upper end of the delivery pipe 302, and the tail end is connected to the liquid collection device. The enriched liquid spiral tube 303 has an inner diameter of 10-30 mm, 8-10 spiral turns, and a trapezoidal or elliptical cross-sectional shape. It adopts a uniform cross-section / gradually changing spiral cavity structure, and attracts the gas-liquid mixture through high-speed negative pressure to form a strong centrifugal + turbulent shear cyclone field, driving the micro-droplets to produce the following motion behavior: Tangential rotation + axial propulsion + radial migration + collision coalescence: droplets undergo tangential and radial motion under the action of centrifugal force. In the enriched liquid spiral tube 303, the droplets collide and coalesce into larger droplets. Ultimately, most of the droplets coalesce onto the outer wall of the enriched liquid spiral tube 303 to form a clear water flow. Droplet-droplet and droplet-wall collisions are continuously generated in the enriched liquid spiral tube 303; Enhance the CO2 absorption process through droplet condensation, gas entrainment, and liquid film dragging effect; Actual measurements show that more than 90% of the CO2 conversion reaction can be completed by controlling the reaction time within <1ms, the droplet coalescence efficiency is controlled to be ≥90%, and the total recovery rate of the system can easily reach more than 95% after multiple spray cycles. The temperature of the CO2 enriched liquid is maintained at 20–35°C to avoid affecting algae cultivation.

[0025] The gas outlet 304 is connected to a negative pressure pump 8 through a first gas outlet pipe 7. A second collecting tank 9 is provided between the first collecting tank 6 and the biotransformation mechanism 4. A valve can be provided between the first collecting tank 7 and the second collecting tank 9. The second collecting tank 9 is connected to the negative pressure pump 8 through a second gas outlet pipe 10. A valve can be provided between the second collecting tank 9 and the negative pressure pump 8. The negative pressure pump 8 gives the second collecting tank 9 a negative pressure to ensure that the CO2 enriched liquid is sucked into the second collecting tank 9. Then, the part of the air that maintains the negative pressure is discharged along the second gas outlet pipe. Because the CO2 is absorbed by the droplets, the gas at this time is already clean gas.

[0026] like Figure 1 As shown, the biotransformation mechanism 4 includes several photobiological reaction tanks 401 connected to the liquid collection device, an LED simulated lighting system, and a temperature control system. The Chlorella solution is introduced into the photobiological reaction tanks 401, and a pH monitoring and adjustment module is provided in the photobiological reaction tanks.

[0027] Example 1: This system was used to treat simulated flue gas (10% CO2 concentration). The droplet diameter was set within 10 µm, the droplet volume fraction accounted for 0.5% to 5% v / v of the gas volume, the CO2 concentration in the CO2-enriched gas was 2–10%, the spray flow rate was 1–50 mL / min, the pH of the atomized liquid was maintained at 7–10, and the gas flow rate in the enriched liquid spiral tube 303 was controlled at 8 m / s. The CO2 capture efficiency was measured to be above 92.5%. After the separated and recovered CO2-enriched liquid was treated by the algae system, the growth rate of Chlorella was significantly improved, the photosynthesis efficiency was enhanced, and efficient bioconversion of CO2 was achieved.

[0028] Example 2: In the actual treatment of industrial tail gas (5% CO2 concentration), the droplet size is set to 5µm, the droplet volume fraction accounts for 5%~10% v / v of the gas volume, the CO2 concentration in the CO2-enriched gas is 5-10%, the spray flow rate is: 1-50 mL / min, the pH of the atomized liquid is maintained at 7-10, and the gas velocity of the enriched liquid spiral tube 303 is 12 m / s. Under the conditions, the CO2 capture efficiency of this system exceeds 85%, zero emissions are achieved after treatment with Chlorella, and the output oxygen concentration is significantly improved, which fully meets the on-site environmental treatment requirements.

[0029] Example 3: For the treatment of coal-fired power plant boiler exhaust gas (CO2 concentration 12-15%), the micro-droplet diameter is controlled at 1-5μm to match the demand for rapid mass transfer of CO2 in high-concentration gas. The volume fraction of the micro-droplet accounts for 10%-15% v / v of the gas volume. The CO2 concentration in the CO2-enriched gas is 10-20%. The spray flow rate is 1-50 mL / min, the pH of the atomized liquid is maintained at 7-10, and the gas flow rate of the enrichment liquid spiral tube 303 is set to 10 m / s. The CO2 capture efficiency is stable at above 95%. After membrane filtration and impurity removal, the liquid is directly connected to the greenhouses around the power plant for soilless cultivation of tomatoes and strawberries. The crop yield is increased by 20%, and the use of chemical fertilizers is reduced by 30%, realizing a closed loop of "carbon capture-agricultural value-added".

[0030] Example 4: Treatment of cement production kiln tail gas (CO2 concentration 18-22%), the micro-droplet diameter is optimized to 30-40μm, the micro-droplet volume fraction accounts for 15%~20% v / v of the gas volume, the CO2 concentration in the CO2-enriched gas is 20-30%, the spray flow rate is 1-50mL / min, the pH of the atomized liquid is maintained at 7-10, and the CO2 capture efficiency is maintained above 88%.

[0031] Example 5: Treatment of biogas / landfill gas (CO2 concentration 30-40%): The droplet diameter is controlled at 50 μm, the droplet volume fraction accounts for 0.5% to 20% v / v of the gas volume, the CO2 concentration in the CO2-enriched gas is 30-40%, the spray flow rate is 1-50 mL / min, the pH of the atomized liquid is maintained at 7-10, the CO2 capture efficiency reaches 90%, and the CH4 concentration of the gas at the tail outlet of the transmission pipe is increased from 60% to 98%, meeting the GB18047 biogas standard.

[0032] This application utilizes a high-speed gas flow field to form a strong rotation (cyclone); the absorption liquid is sprayed into the cyclone area in the form of a high-pressure jet; under the action of impact and shear, the liquid is atomized into micron-sized droplets; the gas-liquid contact area and time are greatly increased, and the CO2 mass transfer efficiency is enhanced.

[0033] This application has a small size and compact structure, can achieve continuous operation and rapid absorption, and is compatible with a variety of amine absorption liquids. It is suitable for industrial exhaust gas purification, air conditioning return air purification and other scenarios.

[0034] After the carbon dioxide is collected, it is used to reproduce industrial Chlorella, which can be used as biofuel. This achieves efficient utilization of CO2 and has practical potential for industrial promotion.

[0035] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. Micro-droplet gas cyclone absorption carbon dioxide capture and conversion system, characterized by: The invention comprises a micro-droplet spray mechanism (1) for atomizing an absorption liquid, a CO2 input mechanism (2) for adjusting the CO2 concentration, a spiral vortex absorption mechanism (3) for adsorbing CO2, a biotransformation mechanism (4) for CO2 absorption, and a PLC control platform. The micro-droplet spray mechanism (1) is connected to the CO2 input mechanism (2) via a gas mixing chamber (5), the gas mixing chamber (5) is connected to the spiral vortex absorption mechanism (3), the spiral vortex absorption mechanism (3) is connected to the biotransformation mechanism (4) via a liquid collecting device, and the liquid collecting device comprises a first collecting tank (6) connected to the spiral vortex absorption mechanism (3) and the biotransformation mechanism (4) via a pipeline, and a peristaltic pump arranged in the first collecting tank (6).

2. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 1, characterized in that: The micro-droplet spray mechanism (1) is a high-pressure micro-hole nozzle or an electric atomizing nozzle.

3. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 2, characterized in that: The CO2 input mechanism (2) comprises a gas mixer, and the gas mixer is connected to a mass flow controller.

4. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 3, characterized in that: The spiral cyclone absorption mechanism (3) comprises a plurality of spiral tube separators (301), wherein the spiral tube separators (301) comprise a delivery pipe (302) located in the center, and a plurality of enriched liquid spiral tubes (303) for adsorbing CO2 are connected to the periphery of the delivery pipe (302), wherein the top end of the delivery pipe (302) is connected to a gas mixer, and the tail end is a gas outlet (304), and the top end of the enriched liquid spiral tube (303) is connected to the upper end of the delivery pipe (302), and the tail end is connected to a liquid collecting device.

5. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 4, characterized in that: The enrichment liquid spiral tube (303) has an inner diameter of 5-50 mm, a number of spiral turns of 2-20, and a cross-sectional shape of a trapezoid, triangle, circle, or ellipse.

6. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 5, characterized in that: The gas outlet (304) is connected to a negative pressure pump (8) via a first gas outlet pipe (7); a second collection tank (9) is provided between the first collection tank (6) and the bioconversion mechanism (4); and the second collection tank (9) is connected to the negative pressure pump (8) via a second gas outlet pipe (10).

7. The micro-droplet gas cyclone absorption carbon dioxide capture and conversion system according to claim 6, characterized in that: The biotransformation mechanism (4) comprises a plurality of photobiological reaction tanks (401) connected to a liquid collection device, an LED simulated lighting system, and a temperature control system. A Chlorella solution is introduced into the photobiological reaction tanks (401), and a pH monitoring and adjustment module is provided in the photobiological reaction tanks (401).

8. A method using the capture conversion system according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) The micro-droplet spray mechanism (1) atomizes the absorption liquid into micro-droplets, and the CO2 input mechanism (2) adjusts the CO2 waste gas into CO2-enriched gas, and completes the preliminary turbulent mixing of the micro-droplets and the CO2-enriched gas in the gas mixing chamber (5) to obtain a gas-liquid mixture; (2) The gas-liquid mixture enters the spiral tube separator (301) under the action of the negative pressure pump (8) to dissolve the CO2 gas, with the gas linear velocity being 6-20 m / s, to obtain a CO2-enriched liquid; (3) Gas-liquid separation, the CO2-enriched liquid is transported to the photobiological reactor (401) for carbon sequestration.

9. The method according to claim 8, characterized in that: In the step (1), the particle size D50 of the microdroplets is ≤50µm, the volume fraction of the microdroplets accounts for 0.5% to 20% v / v of the gas volume, and the CO2 concentration in the CO2-enriched gas is 2–40%; Spray flow rate: 1-50 mL / min; The pH of the nebulized liquid was maintained at 7-10.

10. The method according to claim 9, characterized in that: In step (3), the LED simulation illumination system adopts a mixed illumination of red light 660nm + blue light 450nm, with an intensity of 300-800μmol / m² / s; the temperature control system controls the temperature at 25-30°C; and the pH monitoring and adjustment module controls the pH at 6.8-7.5.

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