Microalgae separation microfluidic carbon sequestration and air purification device

Abstract

A microalgae separation microfluidic carbon fixation and air purification device is disclosed. This invention aims to address the limitation of existing indoor air filtration technologies in simultaneously removing PM2.5. 2.5 This invention addresses the technical challenges of comprehensively addressing the needs for VOCs, CO2, and supplementing O2. The microalgae-separated microfluidic carbon fixation and air purification device comprises multiple reactors, magnets, an ultrasonic device, water pipes, a visible light source, a bidirectional water pump, a pH sensor, a turbidity sensor, and a controller. This invention utilizes MOF (Metal-Oxygen Foil) to adsorb CO2 and VOCs, and leverages microalgae photosynthesis to efficiently fix and convert CO2 and release O2. Simultaneously, the MOF is separated from the microalgae through magnetic and pH measurements, enabling the recycling of core functional materials and convenient recovery of high-value biomass. The device features a compact design, adaptable to various indoor environments, and provides a sustainable solution for optimizing indoor air quality and controlling greenhouse gases.

Description

Technical Field

[0001] This utility model relates to a microalgae carbon fixation and air purification device. Background Technology

[0002] Indoor air pollution (such as PM2.5) 2.5 Volatile organic compounds (VOCs) and CO2 pose health threats. Traditional air purification technologies (such as HEPA filters and activated carbon) can effectively remove particulate matter (PM2.5). 2.5 It is effective against some VOCs, but has significant shortcomings in dealing with indoor air pollution: (1) It is basically ineffective against CO2 and cannot solve the problem of CO2 concentration accumulation caused by dense crowds and insufficient ventilation; (2) The removal of VOCs is not lasting and is limited by the capacity, selectivity and saturation of the adsorbent, making it difficult to achieve efficient, stable and broad-spectrum VOCs purification; (3) It lacks O2 replenishment function and cannot improve indoor oxygen levels; (4) The core mechanism is pollutant transfer / enrichment (non-degradation / conversion), which generates waste filter material that needs to be treated (secondary pollution risk).

[0003] The technology of fixing CO2, releasing O2, and generating biomass through microalgae photosynthesis has shown potential in the field of carbon emission reduction. However, traditional microalgae carbon fixation systems have many shortcomings: they usually rely on inefficient gas-liquid mass transfer methods (such as spraying), with light energy conversion efficiency generally below 5%; the systems are bulky; they lack effective VOCs degradation capabilities; and they are difficult to directly adapt to indoor environments with higher requirements for purification efficiency and space. Patent CN216137005U discloses an indoor carbon-fixing landscape aquarium that relies on spraying for carbon fixation, which has low efficiency (light conversion efficiency <5%), no VOCs degradation, and is limited to aquarium settings.

[0004] Metal-organic framework (MOF) materials are characterized by their ultra-high specific surface area (typically >1000 m²). 2 With their unique pore structures, MOFs exhibit excellent performance in the adsorption and separation of CO2 and VOCs. However, when used alone, MOFs are limited to physical / chemical adsorption, making it difficult to achieve biotransformation and resource utilization of pollutants, and also unable to address the issue of oxygen release. Furthermore, the recycling efficiency and long-term stability of MOFs pose challenges for practical applications.

[0005] Therefore, existing technologies (traditional filter adsorption purifiers, traditional microalgae carbon fixation systems, and MOF adsorbents used alone) are all insufficient to meet the requirements of efficient and simultaneous removal of PM2.5 in indoor environments. 2.5 It meets the comprehensive needs of VOCs, CO2, and supplementing O2.

[0006] The self-assembly of MOFs on the surface of microalgae can significantly improve the photosynthetic carbon fixation efficiency. Utilizing the high CO2 capture capacity of MOF materials and their synergistic effect with microalgae, CO2 can be directionally adsorbed and converted into transportable HCO3. - This significantly enhances the photosynthetic efficiency of microalgae while optimizing water and air purification. Research by Li Dingyi et al. shows that CO2 captured by MOFs is released from the MOFs by converting it into bicarbonate, which is then transported into the microalgal cells via the periplasm. This strategy significantly increased the enzyme activity of *Rubisco*, raising its carbon fixation rate to 1.9 times that of the control group (Nature Communications, 2023, 14(1):5337). However, devices using this method are currently poorly documented. Utility Model Content

[0007] This invention aims to address the limitations of existing indoor air filtration technologies in achieving efficient and simultaneous removal of PM2.5. 2.5 To address the technical challenges of comprehensively addressing the needs for VOCs, CO2, and supplementing O2, a microfluidic carbon fixation and air purification device for microalgae separation is provided.

[0008] The microalgae separation microfluidic carbon fixation and air purification device of this utility model includes an outer shell, multiple reactors, HEPA filters, magnets, ultrasonic devices, horizontal water pipes, conduits, vertical water pipes, visible light sources, exhaust fans, and bidirectional water pumps.

[0009] The outer casing contains multiple horizontally arranged parallel reactors. Each reactor has a hollow structure, with a side plate on each of its two end faces. Above each side plate is a vent, one for air inlet and the other for air outlet. A HEPA filter is installed outside each of the inlet and outlet, and an induced draft fan is installed outside each HEPA filter. The airflow generated by the two induced draft fans moves in the same direction. The inner wall of the reactor is coated with TiO2. A visible light source is located at the top inside the reactor.

[0010] All reactors in the same row are connected to the same horizontal water pipe. One end of each horizontal water pipe is connected to a vertical water pipe. Both the horizontal and vertical water pipes are located inside the HEPA filter. The bottom end of the vertical water pipe is connected to one end of a conduit. A bidirectional water pump is installed on the conduit. The other end of the conduit is connected to the inner cavity of the ultrasonic device. A magnet is installed at one end of the ultrasonic device. The ultrasonic device also has an inlet / outlet water pipe connected to the inner cavity.

[0011] The usage method and working principle of the microalgae separation, microfluidic carbon fixation, and air purification device of this invention are as follows:

[0012] The visible light source is activated, and two exhaust fans are started, with the air generated by the two fans moving in the same direction. Air enters the reactor through the air inlet. The mixed suspension of MOF and microalgae first enters the inner cavity of the ultrasonic device through the inlet / outlet water pipes. Then, the bidirectional water pump is started, and the mixed suspension of MOF and microalgae enters the reactor sequentially through the conduit, vertical water pipe, and horizontal water pipe. The reaction then begins in the reactor, where MOF catalyzes the conversion of CO2 in the air to HCO3. - The process involves adsorbing VOCs, fixing CO2 and releasing O2 through photosynthesis by microalgae, and photocatalytically degrading VOCs under visible light. When air filtration is complete or the water quality is poor and the MOF and microalgae suspension needs to be replaced, the bidirectional water pump is activated via the controller to sequentially pump the MOF and microalgae suspension from the reactor through horizontal, vertical, and conduit pipes into the inner cavity of the ultrasonic device. A saturated solution of HCl or CO2 is added to bring the pH to 5.5–6. The ultrasonic function of the device and the magnet function are then activated. The MOF and microalgae, which were originally bound together, are separated using pH adjustment and ultrasound. The magnet then adsorbs the MOF onto one side of the magnet and separates it, achieving a recovery rate >98%. At this point, the liquid mainly contains microalgae, and the MOF and microalgae are separated. The microalgae are then manually filtered and recovered for use in feed, fuel, or chemicals.

[0013] This invention utilizes a synergistic MOF-microalgae chemical-biological interface to adsorb CO2 and VOCs through MOF adsorption and catalytic conversion of CO2 into a form more readily utilized by microalgae. Microalgae photosynthesis efficiently fixes and converts CO2 and releases O2. TiO2 photocatalysis is introduced for deep VOC degradation. This integrated system features a compact design, adaptable to various indoor environments (homes, classrooms, offices, greenhouses, etc.), providing an efficient and sustainable solution for indoor air quality optimization and greenhouse gas control.

[0014] Compared with the prior art, the present invention has the following significant advantages:

[0015] Comprehensive purification: This utility model's device can reduce CO2 from 2000ppm to 250-350ppm within 3-5 hours, and PM2.5... 2.5 With a removal rate of >99.5%, VOCs removal rate of >90%, and O2 concentration increased by 23%, it is suitable for scenarios such as homes, classrooms, and greenhouses.

[0016] Highly efficient carbon fixation: light conversion efficiency 10.5%, carbon fixation rate 1.5 g / L·h, biomass yield 0.8 g / L·d;

[0017] Suitable for multiple scenarios: wall-mounted (home), freestanding (classroom), clustered (greenhouse / public place);

[0018] Low cost: occupies less than 0.5m² 2 Power consumption is 40-200W, and operating cost is 0.07-0.4 yuan / day. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the microalgae separation microfluidic carbon fixation and air purification device according to specific implementation method one;

[0020] Figure 2 This is a frontal view of the front sidewall 1-1 after it is opened in the first specific implementation method (i.e., Figure 1 (Left-side view in the text). Detailed Implementation

[0021] This embodiment is a microfluidic carbon fixation and air purification device for microalgae separation, such as... Figure 1 and Figure 2 As shown,

[0022] It includes an outer casing 1, multiple reactors 2, HEPA filter 3, magnet 4, ultrasonic device 5, horizontal water pipe 6, conduit 7, vertical water pipe 8, visible light source 9, exhaust fan 12, and bidirectional water pump 13;

[0023] Multiple parallel reactors 2 are horizontally arranged within the outer casing 1. Each reactor 2 has a hollow structure. A side plate 2-2 is installed on each of the two end faces of the reactor 2. Above each side plate 2-2 is a vent 2-1, one serving as an air inlet and the other as an air outlet. A HEPA filter 3 is installed on the outside of each air inlet and outlet. An induced draft fan 12 is installed on the outside of each of the two HEPA filters 3 (the HEPA filter 3 and induced draft fan 12 at the air outlet end are not shown in the figure). The airflow generated by the two induced draft fans 12 moves in the same direction. A TiO2 coating is applied to the inner wall of the reactor 2. A visible light source 9 is installed at the top inside the reactor 2.

[0024] All reactors 2 located in the same row are connected to the same horizontal water pipe 6. One end of each horizontal water pipe 6 is connected to a vertical water pipe 8. The horizontal water pipe 6 and the vertical water pipe 8 are both located inside the HEPA filter 3. The bottom end of the vertical water pipe 8 is connected to one end of the conduit 7. A bidirectional water pump 13 is installed on the conduit 7. The other end of the conduit 7 is connected to the inner cavity of the ultrasonic device 5. A magnet 4 is installed on one end of the ultrasonic device 5. An inlet / outlet water pipe 5-1 is also installed on the ultrasonic device 5 and is connected to the inner cavity.

[0025] Preferably, the reactor 2 has a cylindrical structure with an inner diameter of 50mm to 80mm.

[0026] Preferably, each horizontal water pipe 6 is equipped with a solenoid valve at one end near the vertical water pipe 8; each horizontal water pipe 6 is equipped with a pH sensor and a turbidity sensor inside; the signal output terminals of the pH sensor and the turbidity sensor are connected to the signal input terminal of the controller; the signal input terminals of the solenoid valve, the two exhaust fans 12, the bidirectional water pump 13 and the visible light source 9 are all connected to the signal output terminal of the controller, which can perform electrical or automatic control of the start and stop of each device.

[0027] Preferably, the visible light source 9 generates 450nm visible light, and the TiO2 coating on the inner wall of the reactor 2 photocatalytically degrades VOCs under the action of visible light.

[0028] Preferably, a support frame 11 is also provided inside the outer casing 1 to support the reactor 2. The support frame 11 is in close contact with both the outer wall of the reactor 2 and the inner wall of the outer casing 1. The support frame 11 firstly supports the reactor 2, and secondly seals the gap between the reactor 2 and the inner wall of the outer casing 1. This allows air to be drawn into the reactor 2 by the induced draft fan 12, thereby improving the reaction efficiency.

[0029] Preferably, the HEPA filter 3 and the blower 12 are both installed on the side wall of the outer casing 1, with one HEPA filter 3 and one blower 12 installed on each side wall; the side wall 1-1 of the outer casing 1 near the air inlet of the reactor 2 is connected to the adjacent side wall by a hinge to form a door structure that can be opened and closed, and opening this door structure facilitates cleaning of the inner cavity of the reactor 2.

[0030] Preferably, both the conduit 7 and the ultrasonic device 5 are located outside the outer casing 1, and the magnet 4 is an electromagnet, with the signal input terminal of the electromagnet connected to the signal output terminal of the controller.

[0031] The usage method and working principle of the microalgae separation microfluidic carbon fixation and air purification device in this embodiment are as follows:

[0032] A mixed suspension of MOF and microalgae was prepared (for example, the microalgae type was Chlorella, and the concentration in the suspension was 2.1 × 10⁻⁶). 6The MOF type is NH2-MIL-101-Fe, and its concentration in the suspension is 50 mg / L. The two are then mixed evenly. The mixture enters the inner cavity of the ultrasonic device 5 through the inlet / outlet water pipe 5-1. The solenoid valve on the horizontal water pipe 6 is opened (the number of solenoid valves opened depends on the requirements; the solenoid valves are existing equipment and not shown in the diagram). The visible light source 9 is activated via the controller, and two exhaust fans 12 are activated via the controller. The air generated by the two exhaust fans 12 moves in the same direction, and the air enters the reactor 2 through the air inlet. The bidirectional water pump 13 is activated via the controller to sequentially introduce the mixed suspension 10 of MOF and microalgae into the reactor 2 through the conduit 7, vertical water pipe 8, and horizontal water pipe 6, with the liquid level below the vent 2-1. Then, the reaction begins in the reactor 2, where the MOF catalyzes the conversion of CO2 in the air to HCO3. - The microalgae adsorb VOCs, fix CO2 and release O2 through photosynthesis, and the TiO2 coating on the inner wall of reactor 2 photocatalytically degrades VOCs under the action of visible light source 9. pH and turbidity sensors transmit the liquid water quality from the horizontal water pipe 6 to the controller. Turbidity represents the concentration of microalgae in the water and should not be too high, requiring a range of 0.1-10 g / L; pH should be between 7 and 9. The controller can adjust the light intensity of visible light source 9 and add acid or alkali agents to the inner cavity of ultrasonic device 5 to achieve the desired results.

[0033] When air filtration is completed or the water quality is poor and the mixed suspension of MOF and microalgae 10 needs to be replaced, the bidirectional water pump 13 is started by the controller to sequentially introduce the mixed suspension of MOF and microalgae 10 in reactor 2 into the inner cavity of ultrasonic device 5 through horizontal water pipe 6, vertical water pipe 8 and conduit 7. HCl or CO2 saturated solution is added to bring the pH to 5.5-6, and the ultrasonic function of ultrasonic device 5 and the magnetic function of magnet 4 are activated. MOF and microalgae, which were originally combined, are separated by pH adjustment and ultrasound. Then, magnet 4 adsorbs MOF to one side of magnet 4 and separates it, with a recovery rate of >98%. At this time, the liquid mainly contains microalgae. MOF and microalgae are separated, and the microalgae are manually filtered and recovered for use in feed, fuel or chemicals.

[0034] This implementation method constructs a synergistic MOF-microalgae chemical-biological interface, utilizing MOF to adsorb CO2 and VOCs, and then catalyzing the conversion of CO2 into a form more readily utilized by microalgae. Microalgae photosynthesis efficiently fixes and converts CO2, releasing O2. TiO2 photocatalysis is introduced for deep degradation of VOCs. Simultaneously, MOF and microalgae are separated using magnetism and pH, enabling the recycling of core functional materials and convenient recovery of high-value biomass. This integrated system features a compact design, adaptable to various indoor settings (homes, classrooms, offices, greenhouses, etc.), providing an efficient and sustainable solution for indoor air quality optimization and greenhouse gas control.

[0035] Compared with the prior art, this embodiment has the following significant advantages:

[0036] Comprehensive purification: This utility model's device can reduce CO2 from 2000ppm to 250-350ppm within 3-5 hours, and PM2.5... 2.5 With a removal rate of >99.5%, VOCs removal rate of >90%, and O2 concentration increased by 23%, it is suitable for scenarios such as homes, classrooms, and greenhouses.

[0037] Highly efficient carbon fixation: light conversion efficiency 10.5%, carbon fixation rate 1.5 g / L·h, biomass yield 0.8 g / L·d;

[0038] Resource recycling: MOF cycle 10 times, microalgae produce feed / β-carotene (output value > 100 yuan / kg);

[0039] Suitable for multiple scenarios: wall-mounted (home), freestanding (classroom), clustered (greenhouse / public place);

[0040] Low cost: occupies less than 0.5m² 2 Power consumption is 40-200W, and operating cost is 0.07-0.4 yuan / day.

Claims

1. A microalgae separation microfluidic carbon sequestration and air purification device, characterized in that, The microalgae separation microfluidic carbon fixation and air purification device includes an outer casing (1), multiple reactors (2), HEPA filter (3), magnet (4), ultrasonic device (5), horizontal water pipe (6), conduit (7), vertical water pipe (8), visible light source (9), exhaust fan (12) and bidirectional water pump (13); The outer casing (1) contains a plurality of parallel reactors (2). The reactors (2) are hollow. Each of the two end faces of the reactor (2) has a side plate (2-2). Each of the two side plates (2-2) has a vent (2-1) above it, one being an air inlet and the other an air outlet. Each of the air inlets and outlets has a HEPA filter (3) on its outer side. Each of the two HEPA filters (3) has an exhaust fan (12) on its outer side. The air generated by the two exhaust fans (12) moves in the same direction. The inner wall of the reactor (2) is coated with TiO2. A visible light source (9) is installed at the top of the inside of the reactor (2). All reactors (2) located in the same row are connected to the same horizontal water pipe (6). One end of each horizontal water pipe (6) is connected to a vertical water pipe (8). Both the horizontal water pipe (6) and the vertical water pipe (8) are located inside the HEPA filter (3). The bottom end of the vertical water pipe (8) is connected to one end of the conduit (7). A bidirectional water pump (13) is installed on the conduit (7). The other end of the conduit (7) is connected to the inner cavity of the ultrasonic device (5). A magnet (4) is installed on one end of the ultrasonic device (5). An inlet / outlet water pipe (5-1) is also installed on the ultrasonic device (5) and is connected to the inner cavity.

2. The microalgae separation microfluidic carbon sequestration and air purification device of claim 1, wherein, The reactor (2) is a cylindrical structure with an inner diameter of 50mm to 80mm.

3. The microalgae separation microfluidic carbon sequestration and air purification device of claim 1, wherein, Each horizontal water pipe (6) is equipped with a solenoid valve at one end near the vertical water pipe (8); each horizontal water pipe (6) is equipped with a pH sensor and a turbidity sensor inside.

4. The microalgae separation microfluidic carbon sequestration and air purification device of claim 3, wherein, The device also includes a controller, and the signal output terminals of the pH sensor and the turbidity sensor are connected to the signal input terminal of the controller; the signal input terminals of the solenoid valve, the two exhaust fans (12), the bidirectional water pump (13) and the visible light source (9) are all connected to the signal output terminal of the controller.

5. The microalgae separation microfluidic carbon sequestration and air purification device of claim 1, wherein, The visible light source (9) produces 450nm visible light.

6. The microalgae separation microfluidic carbon sequestration and air purification device of claim 1, wherein, The HEPA filter (3) and the blower (12) are both installed on the side wall of the outer casing (1); the side wall of the outer casing (1) near the air inlet of the reactor (2) is connected to the adjacent side wall by a hinge.

7. The microalgae separation microfluidic carbon sequestration and air purification device of claim 1, wherein, A support frame (11) is also provided in the inner cavity of the outer shell (1) to support the reactor (2). The support frame (11) is in close contact with the outer wall of the reactor (2) and the inner wall of the outer shell (1).

8. The microalgae separation microfluidic carbon sequestration and air purification device of claim 4, wherein, The conduit (7) and the ultrasonic device (5) are both located outside the outer casing (1), and the magnet (4) is an electromagnet. The signal input terminal of the electromagnet is connected to the signal output terminal of the controller.

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