Microalgae carbon sequestration efficiency improving device

Abstract

The invention provides a microalgae carbon sequestration efficiency improving device with built-in optical fiber bundle-quantum dot light guide, and belongs to the field of biological carbon sequestration. A traditional external light source irradiates a microalgae photobioreactor through a spatial light path, and the problems that light cannot penetrate into algae liquid, and the wavelength is limited by the light source exist. According to the invention, the optical fiber bundle protected by the transparent light guide tube is placed in the microalgae photoreactor for light guide, so that the illumination depth is prolonged, and the illumination area is increased. In addition, a quantum dot solution can be introduced into the light guide tube, and light with a proper wavelength is introduced through the optical fiber to irradiate the quantum dot solution to pump and emit light. The quantum dot has the characteristics of wide absorption spectrum and narrow emission spectrum, can capture ultraviolet-blue-violet light which is difficult to utilize by microalgae chlorophyll, and emits light with new wavelength through fluorescence resonance energy transfer to irradiate microalgae. The built-in optical fiber bundle-quantum dot solution is introduced to guide light and emit light, so that the illumination depth of algae liquid can be prolonged, the illumination area can be increased, the microalgae carbon sequestration efficiency and the biomass yield can be improved, the wavelength can be regulated and controlled based on the fluorescence resonance energy transfer characteristic of quantum dots, the illumination requirements of different types of microalgae can be accurately matched, and the application prospect is wide. And the device adaptation range is expanded.

Description

Technical Field

[0001] This invention relates to the field of biocarbon fixation technology, and in particular to a device for improving the efficiency of microalgae carbon fixation. Background Technology

[0002] With the acceleration of global industrialization, and driven by the goals of "carbon peaking and carbon neutrality" and the need for global climate governance, the development of efficient, low-cost, and environmentally friendly carbon dioxide capture and conversion technologies has become a global research hotspot. Carbon capture methods include physical adsorption, distillation, chemical methods, and biological methods, with microalgae carbon fixation technology belonging to the category of biological carbon fixation. Among a range of plants, microalgae exhibit particularly outstanding carbon fixation capabilities. As a group of photosynthetic microorganisms, they have developed a unique carbon concentration mechanism during their long-term evolution in adaptation to low atmospheric CO2 concentrations.

[0003] At present, the large-scale application of microalgae carbon fixation technology mainly involves placing a light source above the microalgae carbon fixation device to irradiate it, thereby helping microalgae grow and capture carbon. The drawbacks are that the light distance and area are limited, and the wavelength of light that microalgae chlorophyll can effectively absorb is limited, resulting in low carbon fixation efficiency. Summary of the Invention

[0004] This invention proposes a device for improving the carbon fixation efficiency of microalgae. It includes a culture tank containing a microalgae mixture; several transparent light guide tubes arranged concentrically inside a microalgae photobioreactor; and several optical fibers inserted into the transparent light guide tubes. The optical fibers guide light from an external light source and emit light into the surrounding environment. The transparent light guide tubes may also be filled with a quantum dot solution, which absorbs light and emits light of a new wavelength.

[0005] This invention introduces a quantum dot solution as a "light energy converter." Quantum dots can efficiently absorb light and excite new wavelengths of light, transferring light energy. Quantum dots possess a broad absorption spectrum and a narrow emission spectrum, capturing ultraviolet-blue-violet light that is difficult for microalgal chlorophyll to utilize, and efficiently transferring energy to photosynthetic pigments through fluorescence resonance. Based on this characteristic, different quantum dots can be used to precisely match the photosynthetic needs of microalgae, expanding the range of light wavelengths utilized. Furthermore, quantum dots not only accelerate photosynthetic electron transport and carbon assimilation processes, increasing ATP and NADPH generation to improve CO2 fixation rate and biomass yield, but also optimize solution pH, reduce cell aggregation, and lower CO2 mass transfer resistance through surface modification. In addition, quantum dots can enhance the resilience of microalgae in complex environments such as low light, high salinity, and heavy metal pollution. The addition method is simple, easily compatible with existing technologies, and can synergistically enhance with AI regulation and genetic engineering technologies without affecting the high-value utilization of biomass, providing an efficient solution for the large-scale application of microalgal carbon fixation.

[0006] Based on the above technical solutions, the preferred method is to have an optical fiber emit light of a certain wavelength, which is then absorbed by a quantum dot solution and pumped to excite the solution, converting it into light of a new wavelength.

[0007] Furthermore, the algae in the microalgae mixture is Chlorella (which can be replaced with other algae), and the quantum dot solution is indium phosphide quantum dot solution (which can be replaced with other quantum dot solutions according to the characteristics of the microalgae).

[0008] Based on the above technical solutions, preferably, one of the transparent light guide tubes is set in the center of the culture tank, and the remaining transparent light guide tubes are arranged in at least two concentric circles around the center of the culture tank.

[0009] Based on the above technical solutions, preferably, at least three optical fibers are inserted into each transparent light guide tube, and the three optical fibers are closely arranged around the center of the transparent light guide tube.

[0010] Based on the above technical solutions, the preferred embodiment also includes a closed space containing a culture tank; a sensor for detecting the CO2 gas concentration within the closed space; a storage tank for supplying CO2 gas; and a light source located outside the closed space. An inlet is located on the side wall of the closed space, connected to the storage tank, which continuously supplies CO2 gas into the closed space. The light source is also connected to several optical fibers.

[0011] Even more preferably, the initial concentration of CO2 gas inside the enclosed space is 5 to 10 times the concentration of CO2 in the atmosphere.

[0012] Based on the above technical solutions, preferably, it also includes a cover body, which is placed on top of the culture tank; wherein, the cover body is provided with several through holes spaced apart; a transparent light guide tube is inserted into the through holes and fixed on the cover body by interference fit.

[0013] The microalgae carbon fixation efficiency enhancement device of the present invention has the following advantages over the prior art: (1) This experiment used side-emitting optical fiber to guide light, which improved the problem of uneven light energy distribution and severe attenuation in traditional reactors. The optical fiber and the transparent light guide tube were arranged in concentric circles, which increased the light guide path and improved the growth and carbon fixation efficiency of microalgae. This achieved a synergistic improvement in light energy utilization and carbon fixation efficiency of microalgae, while avoiding the impact of direct light heating on microalgae growth.

[0014] (2) Quantum dot solution can be introduced into this experiment. Quantum dots can capture ultraviolet-blue-violet light that is difficult for microalgal chlorophyll to utilize, and efficiently transfer energy to photosynthetic pigments through fluorescence resonance energy transfer. Based on this characteristic, different quantum dots can be used to precisely match the photosynthetic needs of microalgae and expand the range of light wavelengths utilized. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the microalgae carbon fixation efficiency enhancement device of the present invention; Figure 2 This is a radial cross-sectional comparison diagram of the transparent light guide tube of the present invention, where a is three optical fibers tightly arranged in a ring, and b is a single optical fiber independently arranged. Figure 3 This is a perspective view of the culture tank, transparent light guide tube, and cover of the present invention; Figure 4 This is a laboratory verification test diagram of the microalgae carbon fixation efficiency enhancement device of the present invention; Figure 5 The graph shows the relationship between OD value and cell dry weight under the condition that the optical fiber emission wavelength is 680nm. In the graph, a is the group with optical fiber, b is the group without optical fiber, and c is a comparison between the two. Figure 6 The graph shows the relationship between OD value and cell dry weight under the condition of fiber optic emission wavelength of 440nm, where a represents the group with fiber optics, b represents the group without fiber optics, and c represents a comparison between the two. Figure 7 The graph shows the relationship between the refractive index of the microalgae mixture and the dry weight of the cells, where a represents the group with optical fiber, b represents the group without optical fiber, and c represents a comparison between the two. Figure 8 A comparison of culture time and refractive index between the quantum dot solution group and the ordinary group; Figure 9 This is a graph showing the carbon dioxide concentration data analysis for groups with and without optical fibers.

[0017] In the diagram: 1. Culture tank; 10. Microalgae mixture; 2. Transparent light guide tube; 20. Quantum dot solution; 3. Optical fiber; 4. Enclosed space; 41. Inlet; 5. Sensor; 6. Storage tank; 7. Light source; 8. Cover. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0024] like Figure 1 As shown, combined with Figure 2 and Figure 3The present invention provides a device for improving the carbon fixation efficiency of microalgae, comprising a culture tank 1, a transparent light guide tube 2, and an optical fiber 3.

[0025] The culture tank 1 contains a microalgae mixture 10. The culture tank 1 is generally cylindrical to ensure that the microalgae mixture 10 inside is evenly exposed to light. The culture tank 1 can be made of transparent acrylic material or semi-transparent acrylic material.

[0026] Several transparent light guide tubes 2 are inserted at intervals inside the culture tank 1; the interior of the transparent light guide tubes 2 is isolated from the interior of the culture tank 1, and each of the transparent light guide tubes 2 contains a quantum dot solution 20. The transparent light guide tubes 2 can be test tubes, which together with the optical fiber 3 form a light guiding unit.

[0027] Several optical fibers 3 are inserted into several transparent light guide tubes 2. The optical fibers 3 guide light and emit light to the surroundings. The quantum dot solution 20 absorbs the light and converts the wavelength of the light before re-emitting it. The optical fibers 3 are side-emitting optical fibers, so when they are inserted into the quantum dot solution 20 in the transparent light guide tubes 2, their entire outer periphery will emit light. Side emission improves the problems of uneven light energy distribution and severe attenuation in traditional reactors, achieving a synergistic improvement in light energy utilization and microalgae carbon fixation efficiency, while avoiding the impact of direct light heating on microalgae growth.

[0028] The principle of this scheme is that the complete process of carbon fixation by microalgae is mainly completed by the synergistic action of two key steps: physical carbon fixation and biological carbon fixation. When microalgae perform photosynthesis, it can be further divided into a light reaction stage and a dark reaction stage, which together constitute the core link of biological carbon fixation. To ensure uniform light distribution and improve carbon fixation efficiency, this device uses a side-emitting optical fiber 3 as the light source component inside the culture tank 1. Utilizing the unique side scattering function of the side-emitting optical fiber 3, light can be uniformly delivered to all areas inside the culture tank 1. This design effectively improves the problems of significant light intensity attenuation with transmission distance and the formation of obvious dark areas within the culture tank 1, which are inherent in traditional external light sources. It achieves a redistribution and comprehensive uniform coverage of light intensity within the culture tank 1, providing more stable and balanced lighting conditions for microalgae growth, ultimately improving the carbon fixation efficiency of microalgae. A quantum dot solution 20 is introduced as a "light energy converter" to promote the growth of microalgae in the microalgae mixture 10. Due to their broad absorption spectrum and narrow emission spectrum, quantum dots can capture ultraviolet-blue-violet light, which is difficult for microalgal chlorophyll to utilize. Through fluorescence resonance energy transfer, they efficiently transfer energy to photosynthetic pigments, thus efficiently absorbing light and exciting new wavelengths, thereby improving light energy transfer efficiency. Based on this characteristic, different quantum dots can be used to precisely match the photosynthetic needs of microalgae, expanding the range of light wavelengths utilized. Furthermore, quantum dots not only accelerate photosynthetic electron transport and carbon assimilation processes, increasing ATP (adenosine triphosphate) and NADPH (reductase) production to improve carbon dioxide fixation rates and biomass yield, but also optimize solution pH and reduce cell aggregation through surface modification, lowering carbon dioxide mass transfer resistance. In addition, quantum dots can enhance the resilience of microalgae in complex environments such as low light, high salinity, and heavy metal pollution. Their addition is simple, easily compatible with existing technologies, and can synergistically enhance effects with AI regulation and genetic engineering technologies without affecting the high-value utilization of biomass, providing an efficient solution for the large-scale application of microalgal carbon fixation.

[0029] exist Figure 1 In one embodiment shown, optical fiber 3 emits broadband light, and quantum dot solution 20 absorbs the broadband light and converts it into narrow-spectrum light for emission. Utilizing the pump-excitation luminescence properties of quantum dots, light with wavelengths less than the quantum dot threshold is transmitted to the quantum dot solution 20 via the side-emitting optical fiber 3. After absorbing the light, the quantum dots emit light with wavelengths greater than the threshold wavelength, which is then absorbed by the microalgae, thereby achieving wavelength modulation and improving light energy utilization. Simultaneously, since the types of quantum dots are adjustable, their threshold wavelength and emission wavelength are also variable, thus adapting to various light sources and algal solutions. This overcomes the dependence of photobioreactors on a specific wavelength light source, allowing the device to flexibly adapt to various light sources and microalgae.

[0030] exist Figure 1In one embodiment shown, the wavelength of broadband light is less than 500 nm, and the wavelength range of narrow-spectrum light is 500~700 nm. Through quantum dot conversion, broadband light is converted into narrow-spectrum light that can be absorbed by microalgae.

[0031] exist Figure 1 In one embodiment shown, the algae in the microalgae mixture 10 is Chlorella sp., and the quantum dot solution 20 is indium phosphide quantum dot solution 20. Chlorella sp. is characterized by its high oil content, tolerance to high concentrations of carbon dioxide, rapid growth, and ease of cultivation. Indium phosphide has a stable structure and a long luminescence lifetime, and does not contain toxic heavy metals such as cadmium and lead, posing minimal harm to human health and the ecological environment. It exhibits excellent environmental compatibility and can be safely used in the growth environment of Chlorella sp., making it an environmentally friendly quantum dot material. The pump threshold wavelength of indium phosphide quantum dots is 500 nm, and the emission band is 500–750 nm, meaning it absorbs light with wavelengths less than 500 nm and emits light in the 500–700 nm range. Depending on the characteristics of different microalgae, indium phosphide quantum dots can be replaced with other quantum dot solutions.

[0032] exist Figure 3 In one embodiment shown, one transparent light guide tube 2 is placed at the center of the culture tank 1, and the remaining transparent light guide tubes 2 are arranged in at least two concentric circles around the center of the culture tank 1 to uniformly irradiate the microalgae mixture 20 in the culture tank 1, thereby promoting microalgae growth and improving carbon fixation efficiency.

[0033] exist Figure 3 In one embodiment shown, the lengths of several optical fibers 3 are arranged concentrically, gradually increasing from the inside out. Specifically, 13 sets of transparent light guide tubes 2 and optical fibers 3 can be arranged in the culture tank 1. The 13 sets of light guide units form a light distribution structure of "one in the center + two inner and outer rings," which increases the light guide path and improves the growth and carbon fixation efficiency of microalgae. Each transparent light guide tube 2 simulates 3 optical fibers with a diameter of 3mm. Among them, the optical fiber located in the center of the culture tank 1 is 300mm long, totaling 3 fibers; the optical fiber in the inner ring is 310mm long, totaling 12 fibers; and the optical fiber in the outer ring is 320mm long, totaling 24 fibers, for a total of 39 fibers. It is necessary to ensure that the input end faces of the optical fibers 3 are flat and uniform to guarantee that the light-emitting length of the optical fibers 3 in each set of light guide units is the same.

[0034] exist Figure 2 In one embodiment shown, at least three optical fibers 3 are inserted into each transparent light guide tube 2. These three optical fibers 3 are tightly arranged around the center of the transparent light guide tube 2, which maximizes the light field's density and uniformity while minimizing attenuation in the peripheral areas. (See also...) Figure 2The dashed lines represent the optimal illumination coverage of a single optical fiber 3. As shown in b, when only one optical fiber 3 is set in the transparent light guide tube 2, the optimal illumination coverage of a single optical fiber 3 may not be able to cover the entire radial surface of the transparent light guide tube 2. However, as shown in a, when three optical fibers 3 are set in the transparent light guide tube 2, the optimal illumination coverage of the combination of optical fibers 3 can cover the entire radial surface of the transparent light guide tube 2, thereby ensuring that the quantum dot solution 20 in the entire transparent light guide tube 2 can fully perform light absorption and conversion.

[0035] exist Figure 1 In one embodiment shown, the system also includes an enclosed space 4, a sensor 5, a storage tank 6, and a light source 7.

[0036] The enclosed space 4 contains a culture tank 1, which can be a glass cover to cover the culture tank 1.

[0037] Sensor 5 is used to detect the concentration of carbon source gas within the enclosed space 4. Sensor 5 can be a carbon dioxide concentration monitor; by connecting the data from sensor 5 to the carbon sequestration efficiency monitoring platform, the changes in carbon dioxide concentration within the enclosed space 4 can be monitored in real time, and the carbon sequestration efficiency of this device can be calculated.

[0038] The storage tank 6 provides carbon source gas; the enclosed space 4 is provided with an inlet 41 on its side wall, which is connected to the storage tank 6, and the storage tank 6 continuously inputs carbon source gas into the enclosed space 4.

[0039] The light source 7 is located outside the enclosed space 4; the light source 7 is also connected to several optical fibers 3. The light source 7 can be an LED emitter, thereby controlling the emission spectrum and wavelength of the optical fibers 3.

[0040] exist Figure 1 In one embodiment shown, the initial concentration of carbon source gas inside the enclosed space 4 is 5 to 10 times the concentration of carbon dioxide in the atmosphere, thereby providing an initial environment with sufficient carbon source for microalgae carbon fixation.

[0041] exist Figure 3 In one embodiment shown, a cover 8 is also included. The cover 8 may also be made of transparent or semi-transparent acrylic material; the cover 8 is placed on the top of the culture tank 1; a plurality of through holes are spaced apart on the cover 8; the transparent light guide tube 2 is inserted into the through holes and fixed to the cover 8 by interference fit, ensuring that the transparent light guide tube 2 is vertically inserted into the culture tank 1 and will not tip over.

[0042] To verify whether the microalgae carbon fixation efficiency of this device can meet the requirements, a comparative experiment was conducted, the details of which are described below: This experiment used Chlorella sp. as the experimental algae species. The light guide units were arranged in concentric circles, and an LED generator was set as the light source. The optical fiber 3 was a side-emitting optical fiber, specifically model CFP3.0-A-SL; the quantum dot solution 20 was an indium phosphide quantum dot solution.

[0043] The culture tank 1 is cylindrical, with a working volume of approximately 2.5L, a height of 140mm, and an outer diameter of 160mm.

[0044] Thirteen light guide units are set inside the culture tank 1. Each transparent light guide tube 2 has a diameter of 17mm and a length of 160mm. The "one in the center + two inner and outer rings" layout of the aforementioned embodiment is adopted. Based on the coupling diameter of the LED generator light source 7 and the diameter of the side-emitting optical fiber 3, and to achieve a uniform light field as much as possible, three optical fibers with a diameter of 3mm are simulated in each transparent light guide tube 2. Among them, the optical fiber in the center is 300mm long, with a total of 3 fibers. The optical fibers in the inner ring are 310mm long, with a total of 12 fibers. The optical fibers in the outer ring are 320mm long, with a total of 24 fibers. The total number of fibers is 39. The input end face of the optical fiber 3 is flat.

[0045] The experiment will verify the promoting effect of the device using the following three indicators: microalgal cell dry weight, optical density (OD) of the algal solution, and refractive index of the algal solution. Changes in cell dry weight directly reflect changes in microalgal biomass; the OD value, through its linear relationship with microalgal cell density combined with regression analysis, can indirectly estimate the dynamic changes in biomass; the refractive index of the algal solution is also closely related to the concentration of biomass in the solution, therefore, changes in refractive index can serve as an indirect indicator of biomass changes.

[0046] The specific experimental steps are as follows: (1) Measurement of dry weight of microalgae cells: Shake the microalgae culture medium for 30 seconds to ensure uniform cell suspension and eliminate differences between different areas of the culture dish. Weigh the net weight of the weighing dish. Take liquid from each area of ​​the culture dish, for a total of 20 ml. Centrifuge to concentrate (centrifugation parameters: 3000 rpm, 30 minutes). Discard the supernatant and carefully pour it out, retaining the precipitated microalgae cells. Place the sample in a 70℃ oven and dry for 2 hours until constant weight (the difference between two weighings < 0.0005 g). After drying, quickly transfer to a desiccator to cool (to prevent moisture absorption). Weigh the total weight of the dried sample + weighing dish using an analytical balance.

[0047] (2) Microalgae optical density measurement: Shake the microalgae culture medium for 30 seconds to ensure uniform cell suspension. To eliminate differences between different areas of the culture dish, take 20 ml of liquid from each area of ​​the culture dish. Add blank culture medium to the cuvette (approximately 2 / 3 of its height). Wipe the outer wall of the cuvette to ensure no fingerprints or liquid residue. Place it in the sample cell and press the "Blank" button to calibrate the absorbance to 0. Add the taken microalgae culture medium to the cuvette. Optical density at different wavelengths was measured using a photometer. OD values ​​from 400 nm to 800 nm were exported from the UVPROBE program. Images and data showed that microalgae exhibited good light absorption around 440 nm and 680 nm, which can be used to measure microalgal biomass. Therefore, OD values ​​were calculated for seven wavelengths around 440 nm (blue light) (410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm) and seven wavelengths around 680 nm (red light) (650 nm, 660 nm, 670 nm, 680 nm, 690 nm, 700 nm, 710 nm). Measurements were repeated three times, and the average value (ODavg) was taken. Linear regression analysis was performed on the OD values ​​at these wavelengths and the cell dry weight. The wavelength with the best linearity was selected as the representative value.

[0048] (3) Microalgae Refractive Index Measurement: Stir the microalgae culture medium to ensure uniform cell suspension, then take 5 ml of the culture medium. Use a piece of lint-free paper dampened with a small amount of alcohol to gently wipe the prism surface. Once the prism surface is free of water stains, begin the experiment. Add deionized water to the prism surface of the refractometer and close the cover. Adjust the calibration knob to display a refractive index of 1.3330 (reference value for pure water at 25℃). Shake the 5 ml microalgae culture medium sample to ensure uniform cell distribution. Use a plastic Pasteur dropper to draw a small amount of microalgae suspension and evenly drop it onto the prism surface. Close the cover to prevent air bubbles. Press the read button to read the refractive index value. Repeat the measurement three times for each sample and take the average value.

[0049] See Figure 5 and Figure 6 It can be seen that, under the same culture conditions, the cell dry weight, OD value (at wavelengths of 480 nm and 680 nm), and refractive index of the microalgae in the fiber-optic group were significantly higher than those in the control group without fiber optics; see reference. Figure 7 It can be seen that the quantum dot array has a higher OD value than the built-in fiber array; Reference Figure 8 It can be seen that the refractive index of the quantum dot group increases faster than that of the built-in optical fiber group, which also indicates that the spectral modulation effect of quantum dots further promotes the growth of microalgae.

[0050] In addition, a carbon dioxide concentration monitor is placed inside a rectangular enclosed space 4 as a sensor 5. Carbon dioxide is introduced into the enclosed space 4 through an external storage tank 6 via an inlet 41, and the carbon dioxide concentration is detected. When the carbon dioxide concentration reaches 4100 ppm, an incubator 1 is placed in the enclosed space 4. The change in carbon dioxide concentration is detected and recorded in real time by the sensor 5.

[0051] The atmospheric carbon dioxide concentration is approximately 410 ppm. The carbon dioxide concentration in the enclosed space 4 of this experiment is about 10 times that of the atmosphere, constituting a high-concentration carbon dioxide environment. However, *Chlorella vulgaris* survived well in this enclosed environment and was able to effectively perform carbon fixation activities. (See also...) Figure 9 It can be seen that after about five hours, the carbon dioxide concentration in the enclosed space has dropped to 600 ppm, which is 16% of the initial value. The carbon fixation effect is good and has great potential in practical applications.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for improving the carbon fixation efficiency of microalgae, characterized in that, include: Culture tank (1) containing microalgae solution (10); Several transparent light guide tubes (2) are bundled together and placed into the culture tank (1); Several optical fibers (3) are inserted into the transparent light guide tube (2); Quantum dot solution (20) can be placed inside the transparent light guide tube (2). The optical fiber (3) guides light and emits light to the surroundings. The quantum dot solution (20) can absorb the light emitted by the optical fiber and emit light of a new wavelength after being pumped and excited.

2. The microalgae carbon fixation efficiency enhancement device according to claim 1, characterized in that: The optical fiber (3) transmits the light from the light source into the algal liquid to extend the illumination depth and increase the illumination area.

3. The microalgae carbon fixation efficiency enhancement device according to claim 2, characterized in that: The light transmitted through the optical fiber is radiated onto the quantum dot solution (20), and the quantum dots are pumped and excited to emit light of a new wavelength.

4. The microalgae carbon fixation efficiency enhancement device according to claim 3, characterized in that: The algae in the microalgae mixture (10) is Chlorella (which can be replaced with other microalgae), and the quantum dot solution (20) is an indium phosphide quantum dot solution (which can be replaced with other quantum dots according to the light wavelength required by the microalgae).

5. The microalgae carbon fixation efficiency enhancement device according to claim 1, characterized in that: One of the transparent light guide tubes (2) is set in the center of the culture tank (1), and the remaining transparent light guide tubes (2) are arranged in two concentric circles around the center of the culture tank (1).

6. The microalgae carbon fixation efficiency enhancement device according to claim 5, characterized in that: The lengths of several optical fibers (3) are arranged along concentric circles and gradually increase from the inside to the outside, so that the input end faces of several optical fibers (3) are flat and neat.

7. The microalgae carbon fixation efficiency enhancement device according to claim 1, characterized in that: At least three optical fibers (3) are inserted into each of the transparent light guide tubes (2), and the at least three optical fibers (3) are closely arranged around the center of the transparent light guide tube (2).

8. The microalgae carbon fixation efficiency enhancement device according to claim 1, characterized in that, Also includes: A closed space (4) is provided with the culture tank (1) inside it; Sensor (5) is used to detect the CO2 gas concentration in the enclosed space (4); Gas storage tank (6) provides carbon source gas; The light source (7) is located outside the enclosed space (4); The enclosed space (4) has an inlet (41) on its side wall, which is connected to the storage tank (6). The storage tank (6) continuously inputs carbon source gas into the enclosed space (4). The light source (7) is simultaneously connected to several optical fibers (3).

9. The microalgae carbon fixation efficiency enhancement device according to claim 8, characterized in that: The initial concentration of CO2 gas inside the enclosed space (4) is 5 to 10 times the concentration of CO2 in the atmosphere.

10. The microalgae carbon fixation efficiency enhancement device according to claim 1, characterized in that, Also includes: Cover (8) is placed on top of the culture tank (1); The cover (8) has several through holes spaced apart; the transparent light guide tube (2) is inserted into the through holes and fixed to the cover (8) by interference fit.

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