Internal circulation type blue-green algae culture device based on micro-channel enhanced carbon capture

Abstract

The invention belongs to the technical field of microbial culture, and provides an internal circulation type blue-green algae culture device based on micro-channel enhanced carbon capture, which comprises an absorption liquid storage tank, a carbon dioxide gas cylinder and an up-flow photobioreactor coupled with a micro-channel mixer. By coupling the micro-channel mixer, the contact area of the gas phase and the liquid phase is increased, the heat and mass transfer efficiency in the system is improved, and the efficient fixing and slow-release effects of carbon dioxide are further promoted through the alkaline absorption liquid and micro-bubbles which are generated through dissolution and are not prone to overflowing; meanwhile, the flow and the speed of the gas-liquid mixture entering the blue-green algae culture device can be controlled, so that the carbon source utilization in the blue-green algae culture process is optimized, the blue-green algae growth is optimized, and the biomass yield is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial cultivation, and in particular relates to an internal circulation blue algae cultivation device based on microchannel enhanced carbon capture. Background Art

[0002] The world is currently facing energy crises and environmental problems, especially climate change caused by carbon dioxide emissions. As an efficient photosynthetic microorganism, cyanobacteria have great potential for biological carbon fixation, and the large amount of biomass produced after carbon fixation can be used to prepare high value-added products such as biofuels and bioplastics. However, the existing cyanobacteria cultivation devices need to be improved in terms of carbon capture and fixation capabilities. 2 The low solubility in water means that most of the carbon dioxide introduced in the gas phase does not dissolve, but instead quickly overflows in the form of bubbles, causing cyanobacteria to absorb CO 2 The gas utilization efficiency is low and cannot meet the actual needs of large-scale industrial production and carbon sequestration and emission reduction.

[0003] The solubility of carbon dioxide in algae solution is mainly affected by factors such as the pH value of the solution, temperature, contact time and contact area between the gas and liquid phases, and carbon dioxide partial pressure.

[0004] A microchannel mixer is a device that achieves fluid mixing at a microscale, with the advantages of high efficiency, high precision, and high reaction rate. Using microchannels for gas-liquid mixing helps to increase the contact area, reduce the resistance to mass transfer between phases, and produce micro-nano bubbles that are more soluble in the liquid phase and have a longer residence time. Compared with macroscopic bubbles, micron-sized bubbles can stay in water for up to several minutes. Bubbles of 0.1μm or smaller can stay in water for longer periods of time, up to several days or even months.

[0005] Coupling the microchannel with the cyanobacteria reactor and using carbon dioxide micro-nano bubbles for cyanobacteria cultivation can improve the solubility and slow-release effect of carbon dioxide, avoid a large amount of carbon dioxide dissolving in water in a short time causing system acidification and inhibiting the growth of cyanobacteria.

[0006] In view of problems such as short carbon dioxide residence time and low carbon sequestration rate, current cyanobacteria reactors mostly use hollow fiber membranes, Venturi tubes, etc., or use alkaline liquids such as sodium carbonate solution and ammonia water to promote the chemical absorption of carbon dioxide. The pore spacing of the microporous membrane structure alone cannot be precisely controlled. If the pore arrangement is too tight, coalescence between adjacent bubbles will occur, making it difficult to form micro-nano bubbles with smaller sizes, and the adjustable bubble size range is narrow. Existing technologies for enhancing carbon capture using microchannels mostly use physical and chemical methods for absorption, resulting in high consumption of energy and chemical reagents, and lacking effective carbon utilization technologies at the backend. In view of the above problems, the present invention aims to couple a microchannel mixer with a cyanobacteria cultivation device to achieve efficient biological capture and conversion of carbon dioxide, and provide a solution with good application prospects and both environmental and social benefits. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a novel cyanobacteria cultivation device that can effectively enhance the dissolution and utilization of carbon dioxide, thereby promoting the efficient biological capture and conversion of carbon dioxide.

[0008] To achieve the above object, the present invention provides an internal circulation type cyanobacteria cultivation device based on microchannel enhanced carbon capture, which includes an absorption liquid storage tank, a carbon dioxide gas cylinder, and an upflow photobioreactor coupled with a microchannel mixer. The absorption liquid storage tank is connected to the microchannel mixer through a liquid inlet pipeline, the carbon dioxide gas cylinder is connected to the microchannel mixer through a gas inlet pipeline, and the microchannel mixer is connected to the bottom of the upflow photobioreactor through a microchannel liquid outlet pipe.

[0009] In some embodiments, the upflow photobioreactor includes a tank body. Inside the tank body, at least two riser pipes are symmetrically arranged along the center line. The inside of the riser pipes forms an upflow zone, and the outside of the riser pipes forms a downflow zone. A gas distribution device is provided at the bottom of the upflow zone, and the gas distribution device is connected to the microchannel liquid outlet pipe. An exhaust port, a heating rod, and a feeding port are also provided at the top of the tank body. A liquid outlet is provided at the bottom of the tank body.

[0010] In some embodiments, the upflow photobioreactor is provided with a sampling pipe, and the sampling pipe extends from the top of the tank body into the middle of the liquid level inside the tank body. In some embodiments, the upflow photobioreactor further includes an algal liquid parameter monitor.

[0011] In some embodiments, the upflow photobioreactor is further provided with an external circulation liquid inlet pipe, and the other end of the external circulation liquid inlet pipe is connected to the microchannel liquid inlet of the microchannel mixer. Further, an external circulation water pump is provided on the external circulation liquid inlet pipe.

[0012] In some embodiments, the microchannel mixer includes a mixing channel, and a microchannel liquid inlet, a microchannel gas inlet and a microchannel outlet are provided on the mixing channel. In some embodiments, the shape of the microchannel mixer is one of an interdigitated type, a T type, a Y type, a heart type or a column type, preferably a Y type and a T type.

[0013] In some embodiments, the mixing channel is a serpentine channel, and minute protrusions are provided on the inner wall of the serpentine channel; preferably, the minute protrusions are uniformly distributed inside the serpentine channel.

[0014] In some embodiments, a light source system is provided outside the upflow photobioreactor, and the light source system includes an LED lamp.

[0015] In some embodiments, an absorption liquid water pump and a liquid flow controller are provided on the liquid inlet pipe.

[0016] In some embodiments, a pressure reducing valve is provided on the carbon dioxide gas cylinder, and a gas flow controller is provided on the gas inlet pipe.

[0017] Technical effects

[0018] By coupling a microchannel mixer, the present invention increases the contact area between gas and liquid phases, improves the heat and mass transfer efficiency in the system, and further promotes the efficient fixation and slow release effect of carbon dioxide through an alkaline absorption liquid and fine bubbles that are not easily overflowed generated by dissolution. At the same time, the flow rate and rate of the gas-liquid mixture entering the cyanobacteria incubator can be controlled, thereby optimizing the utilization of carbon sources in the cyanobacteria culture process, optimizing the growth of cyanobacteria, and increasing the yield of biomass. Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. Generate carbon dioxide micro-nano bubbles with adjustable sizes to improve the carbon fixation effect

[0020] The size of carbon dioxide bubbles (from the nano level to the micron level, such as 300 - 2000 μm) can be adjusted by designing the internal channel structure and size. Compared with a fiber membrane, the residence time of its bubbles in the aqueous phase is longer, so it is suitable for the cultivation of different species and different diameters of cyanobacteria. The micro-nano bubbles generated by the microchannel mixer significantly increase the solubility of carbon dioxide in the algal solution, avoid the problem of rapid overflow of carbon dioxide, and improve the actual utilization rate of carbon dioxide.

[0021] 2. Optimize the growth conditions of cyanobacteria and increase the yield of cyanobacteria

[0022] Couple the microchannel mixer with the design of an internal circulation upflow bioreactor to promote the capture and fixation of carbon dioxide during the circulation of the algal solution. Through the internal circulation and external circulation systems, efficient mass transfer and uniform distribution of carbon dioxide are achieved, providing a stable carbon source for cyanobacteria and promoting the growth and biomass accumulation of cyanobacteria. The mixing of the alkaline absorbent with carbon dioxide avoids the acidification of the system caused by the short-term and large-scale dissolution of carbon dioxide, maintains the stable pH value of the algal solution, and is beneficial to the growth of cyanobacteria.

[0023] 3. Compact design, efficient operation, and good engineering scale-up effect

[0024] The device of this application has a compact design, small floor area, and simple management and control. In traditional large-scale mixers, amplification effects such as the formation of turbulence and eddies may affect the mixing effect. The microchannel technology uses parallel amplification, improving a single microchannel and summing them up, reducing the influence of the amplification effect. The design of this system has good versatility and can be effectively used for the capture and utilization of carbon dioxide.

[0025] 4. Environmentally friendly and good applicability

[0026] The device of this application realizes the efficient biological capture and conversion of carbon dioxide, reduces greenhouse gas emissions, and at the same time the generated cyanobacterial biomass can be used for the production of biofuels or other high-value-added products, having good environmental and social benefits. At the same time, the present invention has good applicability and is not limited to the cultivation of cyanobacteria. It can be used in combination with other microbial reactors or device structures for carbon dioxide capture and utilization (such as for cultivating microorganisms such as hydrogenotrophic methanogens and autotrophic Clostridium, or other gas-liquid two-phase chemical processes using carbon dioxide as a raw material such as the synthesis of nano-calcium carbonate), and has broad application prospects in the fields of the production of biofuels and high-value-added biochemicals, carbon capture, utilization and storage, and environmental protection. Description of the Drawings

[0027] Figure 1 is a schematic diagram of an internal circulation type cyanobacteria cultivation device based on microchannel enhanced carbon capture according to a preferred embodiment of the present invention;

[0028] Figure 2 is the internal structure diagram of the microchannel mixer 5;

[0029] Figure 3 is the growth curve (optical density OD 730nm change situation) of each test group in Example 2 every day;

[0030] Figure 4 is the change situation of the pH value in the system of each test group in Example 2 from 1 to 6 days.

[0031] Reference numerals: absorption liquid storage tank 1, absorption liquid water pump 2-1, external circulation water pump 2-2, liquid flow controller 3, liquid inlet pipe 4, microchannel mixer 5, microchannel liquid inlet 5-1, microchannel 5-2 gas inlet, microchannel outlet 5-3, serpentine channel 5-4, micro protrusion 5-5, gas inlet pipe 6, gas flow controller 7, carbon dioxide gas cylinder 8, pressure reducing valve 9, external circulation liquid inlet pipe 10, external circulation valve 11-1, monitor valve 11-2, microchannel liquid outlet pipe 12, gas distribution device 13, upflow photobioreactor 14, fixing part 15, exhaust port 16, sampling pipe 17, feeding port 18, riser pipe 19, heating rod 20, heating rod fixing bracket 21, LED lamp 22, liquid outlet 23, algal liquid parameter monitor 24. Detailed implementation manners

[0032] The present invention provides an internal circulation type cyanobacteria culture device based on microchannel enhanced carbon capture, including an absorption liquid storage tank 1, a carbon dioxide gas cylinder 8, and an upflow photobioreactor 14 coupled with a microchannel mixer 5. The absorption liquid storage tank 1 is connected to the microchannel mixer 5 through a liquid inlet pipe, the carbon dioxide gas cylinder is connected to the microchannel mixer 5 through a gas inlet pipe, and the microchannel mixer 5 is connected to the bottom of the upflow photobioreactor 14 through a microchannel liquid outlet pipe.

[0033] In some implementation manners, the upflow photobioreactor 14 is mainly used for culturing cyanobacteria. It includes a tank body, for example, a cylindrical glass tank body. Inside the tank body, at least two riser pipes 19 are symmetrically arranged along the center line. The inside of the riser pipes 19 (i.e., between multiple symmetrically distributed riser pipes 19) forms an upflow zone, and the outside of the riser pipes 19 forms a downflow zone. A gas distribution device 13 is provided at the bottom of the upflow zone, and the gas distribution device 13 is connected to the microchannel liquid outlet pipe 12; the carbon dioxide micro-nano bubble liquid is ejected through a multi-point water distribution system to obtain a high-efficiency mass transfer area and form a uniform upflow. Since the proportion of bubbles in the lower part of the upflow zone is relatively high, its density is small. Coupled with the jet kinetic energy generated by the gas distribution device 13, the algal liquid inside the riser pipes 19 rises. When it reaches the upper part of the upflow zone, the gas escapes from the algal liquid and is discharged through the exhaust port 16. At the same time, the algal liquid becomes heavier and descends under the action of gravity in the downflow zone, and then circulates back into the upflow zone at the bottom of the reactor 14, thus forming an internal circulation of the reactor.

[0034] An exhaust port 16, a heating rod 20, and a feeding port 18 are further provided at the top of the tank body and fixed by a fixing part 15. The exhaust port 16 is used to discharge the waste gas (such as unused carbon dioxide, oxygen, nitrogen, etc.) during the reaction. The heating rod 20 contains a temperature sensor and is used to keep the temperature of the algal liquid in the device at 35 ± 1 °C, and is fixed on the upflow photobioreactor 14 through a heating rod fixing bracket 21. The feeding port 18 is used to add cyanobacteria seed liquid initially and regularly during the cultivation process.

[0035] A liquid outlet 23 is provided at the bottom of the tank body for regularly harvesting cyanobacteria for high-value utilization processes at the backend.

[0036] In some embodiments, the upflow photobioreactor 24 is provided with a sampling tube 17 that extends from the top of the tank body to the middle of the liquid level inside the tank for sampling to monitor cyanobacteria growth indicators such as OD730nm to determine the growth curve and culture cycle of cyanobacteria. In some embodiments, the upflow photobioreactor 14 further includes an algal liquid parameter monitor 24 for detecting some algal liquid samples to achieve intelligent regulation of the algal liquid and the growth state of cyanobacteria through parameters such as dissolved oxygen, pH value, and conductivity.

[0037] In some embodiments, the upflow photobioreactor 14 is further provided with an external circulation inlet pipe 10, and the other end of the external circulation inlet pipe 10 is connected to the microchannel inlet 5-1 of the microchannel mixer 5. Further, an external circulation water pump 2-2 is provided on the external circulation inlet pipe 10 to extract algal liquid from the bottom of the descending zone through the external circulation inlet pipe 10. The algal liquid is pumped into the microchannel inlet 5-1 through the external circulation water pump 2-2, mixed with carbon dioxide, and then enters the upflow photobioreactor 14. Thus, an external circulation pipeline is constructed outside the upflow photobioreactor 14 to further enhance the capture and biological utilization of carbon dioxide.

[0038] In some embodiments, a light source system including LED lights is provided outside the upflow photobioreactor 14. For example, a number of LED lights 22 are provided outside the upflow photobioreactor 14 to provide light for cyanobacteria. Preferably, red and white mixed type LED lights with a light intensity of 50-150 μmol photons·m -2 s -1 .

[0039] In some embodiments, the microchannel mixer 5 includes a mixing channel, and the mixing channel is provided with a microchannel inlet 5-1, a microchannel gas inlet 5-2, and a microchannel outlet 5-3. In some embodiments, the shape of the microchannel mixer 5 is one of a cross-finger type, a T type, a Y type, a heart type, or a column type, preferably a Y type and a T type.

[0040] The microchannel mixer 5 is used for gas-liquid mixing. The microchannel outlet 5-3 is connected to the microchannel liquid outlet pipe 12, and the generated carbon dioxide micro-nano bubble mixture is sent into the cyanobacteria culture device through the gas distribution device 13 for the growth of cyanobacteria. The material of the microchannel mixer 5 is stainless steel 316L or Hastelloy. The microchannel liquid inlet 5-1, the microchannel gas inlet 5-2, and the microchannel outlet 5-3 are respectively connected to the liquid inlet pipe 4, the external circulation liquid inlet pipe 10, the gas inlet pipe 6, and the microchannel liquid outlet pipe 12. Inside the microchannel mixer 5, the mixing channel is a serpentine channel 5-4. The serpentine channel 5-4 adopts a tortuous design to increase the flow mixing path. At the same time, the inner wall of the channel contains minute protrusions 5-5 for inducing local eddies. This is because the gas-liquid disturbance in the non-linear microchannel will be enhanced, resulting in an increase in the flow velocity near the irregular area and the formation of eddies near the corners, etc. Therefore, adding baffles or adjusting the shape of the microchannel can effectively promote the disturbance of the gas-liquid two-phase fluid and improve the mass transfer effect. The temperature of gas-liquid mixing is 20-36 °C, the liquid inlet flow rate is 4-8 L / min, the gas inlet flow rate is 3-8 L / min, and the gas inlet pressure is 2-5 bar. The width of the microchannel is 45-200 μm, and the internal dimensions can be designed and adjusted to form carbon dioxide micro-nano bubbles (300-2000 μm) of different sizes suitable for the growth of cyanobacteria, which can effectively increase the solubility of CO 2 , and fully mix with cyanobacteria during the flow of the algal liquid to achieve gas exchange.

[0041] In the specific implementation manner, the function of the absorption liquid storage tank 1 is to store the alkaline absorption liquid for carbon capture. The alkaline absorption liquid can be cyanobacteria culture medium, or sterilized anaerobic digestion effluent biogas slurry, seawater, sodium carbonate solution containing nutrient elements, etc. that are suitable for the growth of cyanobacteria. An absorption liquid water pump 2-1 and a liquid flow controller 3 are provided on the liquid inlet pipe 4. The absorption liquid water pump 2-1 is used to pump the absorption liquid in the absorption liquid storage tank 1 into the microchannel liquid inlet 5-1 through the liquid inlet pipe 4, and the liquid flow controller 3 is used to control the flow rate of the absorption liquid.

[0042] In the specific implementation manner, the carbon dioxide gas cylinder 8 contains pure carbon dioxide gas, or can also contain a gas mixture with a higher carbon dioxide content (such as incinerator flue gas, anaerobic digestion biogas, etc.). A pressure reducing valve 9 is provided on the carbon dioxide gas cylinder 8, and it is adjusted to a suitable gas pressure through the pressure reducing valve 9 and connected to the microchannel gas inlet 5-2 through the gas inlet pipe 6. A gas flow controller 7 is provided on the gas inlet pipe 6, and the gas flow rate entering the microchannel mixer 5 is controlled through the gas flow controller 7.

[0043] Example 1:

[0044] 1. Culture medium preparation

[0045] Use an alkaline absorbent as the cyanobacteria culture medium. Store the alkaline absorbent in the alkaline absorbent storage tank 1, and pump the absorbent into the microchannel inlet 5-1 of the microchannel mixer 5 through the absorbent water pump 2-1, the liquid flow controller 3, and the liquid inlet pipe 4.

[0046] 2. Carbon dioxide injection

[0047] Inject carbon dioxide gas from the carbon dioxide gas cylinder 8. After the gas is adjusted to the appropriate pressure by the pressure reducing valve 9, it enters the microchannel gas inlet 5-2 of the microchannel mixer 5 through the gas inlet pipe 6 and the gas flow controller 7.

[0048] 3. Gas-liquid mixing and micro-nano bubble generation

[0049] In the microchannel mixer 5, the carbon dioxide gas and the alkaline absorbent are fully mixed under the action of the serpentine channel 5-4 and the micro protrusions 5-5 to form micro-nano bubbles (the liquid inlet flow rate is 4-8 L / min, the gas inlet flow rate is 3-8 L / min, and the gas inlet pressure is 2-5 bar). The material of the microchannel mixer 5 is stainless steel 316L or Hastelloy, and the Y-shaped structure is selected. The serpentine channel contains micro protrusions, and the channel size can be adjusted to generate carbon dioxide micro-nano bubbles of different sizes, improving the solubility of carbon dioxide in the absorbent.

[0050] 4. Internal circulation in the cyanobacteria reactor

[0051] Inject the cyanobacteria seed liquid into the upflow photobioreactor 14 through the feeding port 18. The carbon dioxide micro-nano bubble mixture generated by the microchannel mixer 5 enters the riser 19 of the upflow photobioreactor 14 through the microchannel outlet 5-3 and the air distribution device 13. In the riser 19, the bubbles carry the algal liquid upward. When reaching the upper part of the rising area, the waste gas escapes from the exhaust port 16, and the algal liquid becomes heavier and then descends from the descending area, forming an internal circulation.

[0052] 5. External circulation in the cyanobacteria reactor

[0053] After the absorbent in the upflow photobioreactor 14 reaches the predetermined volume, pump the algal liquid from the bottom of the descending area through the external circulation inlet pipe 10, pump it into the microchannel mixer 5 through the external circulation water pump 2-2, mix it with carbon dioxide again, and then enter the upflow photobioreactor 14 to strengthen the capture and biological utilization of carbon dioxide. The external circulation pipeline adopts the intermittent aeration method, and aerates for 10 minutes every 12 hours.

[0054] 6. Light and temperature control

[0055] Several LED lights 22 are installed outside the upflow photobioreactor 14, and the light intensity is 50-150 μmol photons·m -2 s -1. The heating rod 20 inside the reactor is fixed on the upflow photobioreactor 14 through the heating rod fixing bracket 21, which is used to maintain the temperature of the algal liquid at 35 ± 1 °C to ensure the efficient growth of cyanobacteria.

[0056] 7. Monitoring and harvesting of algal liquid

[0057] The parameters of the algal liquid such as pH value, dissolved oxygen and conductivity are monitored in real time by the algal liquid parameter monitor 24 to optimize the growth conditions of cyanobacteria. The growth curve of cyanobacteria is monitored regularly through the sampling tube 17 to determine the culture cycle. After the culture is completed, the cyanobacterial cells are harvested regularly through the liquid outlet 23 for subsequent high-value utilization.

[0058] A new batch of cycles can be started after harvesting the algal cells.

[0059] Example 2:

[0060] The cyanobacteria species used is Synechococcus sp. PCC 11901.

[0061] The culture medium used is AD7 medium, and the specific composition is: KCl 0.6 g / L, NaNO 3 1 g / L, CaCl 2 ·2H 2 O 0.37 g / L, Na 2 EDTA 30 mg / L, KH 2 PO 4 50 mg / L, H 3 BO 3 2.86 mg / L, MnCl 2 ·4H 2 O 1.81 mg / L, ZnSO 4 ·7H 2 O 0.222 mg / L, Na 2 MoO 4 ·2H2O 1.26 mg / L, CuSO 4 ·5H 2 O 0.079 mg / L, CoCl 2 ·2H 2 O 0.0403 mg / L, NaCl 18 g / L, MgSO4·7H 2 O 5 g / L, Tris 1.0375 g / L, FeCl 3 ·6H 2 O 6.48 mg / L (sterilized separately), VB1 0.004 mg / L (sterilized separately).

[0062] A conical flask with a working volume of 500 mL was used, and 500 mL of AD7 medium sterilized at high temperature and high pressure of 121 °C was added. Carbon dioxide gas was released from a steel cylinder, filtered and sterilized through a 0.22 μm filter membrane, and then passed into different microbubble generation devices to prepare carbon dioxide bubbles of different sizes and dissolved in the medium.

[0063] The pre-cultured algal solution was inoculated into the conical flask, and the initial OD 730nm was adjusted to 0.05. Then the conical flask was placed in a constant temperature incubator at 35 °C, and the light intensity was 120 μmol photons·m -2 s -1 , and they were co-cultured for 6 days. Group A (control group) was directly aerated, and the carbon dioxide bubble size ranges of groups B, C, D, and E were 2000 - 5000 μm, 700 - 2000 μm, 300 - 800 μm, and 0.2 - 0.6 μm respectively (the size of microscale bubbles was measured by a laser particle size analyzer, and the size of nanoscale bubbles was measured by a nanoparticle tracking analyzer).

[0064] Since the inoculation day, 10 mL of the algal solution was sampled every 1 day, and the absorbance value (OD 730nm ) at a wavelength of 730 nm was measured using an enzyme-linked immunosorbent assay reader. Using the AD7 medium as a control, it was repeated 3 times to plot the growth curve. The pH value of the algal solution was measured using a pH meter.

[0065] As Figure 3-4 shown, carbon dioxide micro-nano bubbles can effectively promote the growth of cyanobacterium Synechococcus sp. PCC11901, and the bubble strengthening effect is the best in the range of 300 - 2000 μm. Larger bubbles (2000 - 5000 μm) have a lower solubility in the liquid phase, and a higher proportion of carbon dioxide is lost to the atmosphere; when smaller bubbles (0.2 - 0.6 μm) burst, the disappearance of the gas-liquid interface causes a large amount of energy accumulated by the high-concentration positive and negative ions on the interface to be violently released, and a large number of strongly oxidizing free radicals such as ·OH free radicals are generated, which has a killing effect on this cyanobacterium.

[0066] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. An internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture, comprising an absorption liquid storage tank, a carbon dioxide gas cylinder and an upflow photobioreactor coupled with a microchannel mixer, wherein the absorption liquid storage tank is connected to the microchannel mixer through a liquid inlet pipe, the carbon dioxide gas cylinder is connected to the microchannel mixer through an air inlet pipe, and the microchannel mixer is connected to the bottom of the upflow photobioreactor through a microchannel liquid outlet pipe.

2. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The upflow photobioreactor comprises a tank body, at least two riser pipes are symmetrically arranged along the center line inside the tank body, the interior of the riser pipes constitutes an ascending zone, and the exterior of the riser pipes constitutes a descending zone, an air distribution device is provided at the bottom of the ascending zone, and the air distribution device is connected to the microchannel liquid outlet pipe; an exhaust port, a heating rod and a feeding port are also provided at the top of the tank body; and a liquid outlet is provided at the bottom of the tank body.

3. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The upflow photobioreactor is provided with a sampling tube, and the sampling tube extends from the top of the tank body into the middle of the liquid surface in the tank body.

4. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The upflow photobioreactor further includes an algae liquid parameter monitor.

5. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The upflow photobioreactor is also provided with an external circulation liquid inlet pipe, and the other end of the external circulation liquid inlet pipe is connected to the microchannel liquid inlet of the microchannel mixer.

6. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The microchannel mixer comprises a mixing channel, and a microchannel liquid inlet, a microchannel air inlet and a microchannel outlet are arranged on the mixing channel.

7. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The mixing channel is a serpentine channel, and the inner wall of the serpentine channel is provided with tiny protrusions.

8. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: A light source system is arranged outside the upflow photobioreactor.

9. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The liquid inlet pipeline is provided with an absorption liquid water pump and a liquid flow controller.

10. The internal circulation cyanobacteria cultivation device based on microchannel enhanced carbon capture according to claim 1, wherein: The carbon dioxide cylinder is provided with a pressure reducing valve, and the air intake pipeline is provided with a gas flow controller.

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