Nannochloropsis oculata culture method integrating CO2 recovery and reutilization

Abstract

The invention relates to the technical field of nannochloropsis oculata culture, and discloses a nannochloropsis oculata culture method integrating CO2 recovery and reutilization, which comprises the following steps: constructing a small trapping unit based on a small adsorbent to trap CO2 from low-flow industrial waste gas, and removing impurities in CO2 through a portable washing tower to obtain purified CO2; a high-precision gas analyzer and a sensor are arranged at an inlet and an outlet of the trapping unit, gas components are continuously monitored, and data are transmitted to the central control unit through a wireless communication protocol. According to the nannochloropsis oculata culture method integrating CO2 recovery and reutilization, the activated carbon fiber is selected as an adsorbent, and a compact trapping unit is designed, so that CO2 is efficiently trapped from low-flow industrial waste gas, the trapping efficiency of CO2 is remarkably improved, the occupied space of equipment is reduced, and the method is suitable for large-scale application of a laboratory; a high-precision gas analyzer based on an infrared absorption spectrum technology is mounted at an inlet and an outlet of a trapping unit.

Description

Technical Field

[0001] The invention relates to the technical field of Nannochloropsis cultivation, and in particular to a Nannochloropsis cultivation method integrating CO2 recovery and reuse. Background Art

[0002] Nannochloropsis is a single-cell marine microalgae that has attracted widespread attention for its rapid growth, high photosynthesis efficiency, and rich content of oils, proteins and other valuable bioactive substances. Nannochloropsis cultivation refers to the process of artificially propagating Nannochloropsis in large quantities under specific conditions, aiming to maximize the accumulation of its biomass and target products. However, Nannochloropsis is very sensitive to environmental parameters such as light intensity, water temperature, nutrient solution ratio and CO2 concentration. Traditional methods are difficult to achieve precise regulation of these parameters, which affects the growth rate and biomass of Nannochloropsis. In addition, traditional systems lack the ability to monitor gas composition in real time and cannot dynamically adjust operating parameters according to actual conditions, resulting in unstable CO2 capture effects. At the same time, traditional tail gas recovery devices have a low recovery rate for CO2 that is not fully absorbed, and there is a large demand for fresh CO2 supplementation, which increases operating costs. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for cultivating Chlorella with integrated CO2 recovery and reuse, comprising: constructing a small capture unit based on a miniaturized adsorbent to capture CO2 from low-flow industrial waste gas, removing impurities in CO2 through a portable scrubber to obtain purified CO2; deploying a high-precision gas analyzer and sensor at the inlet and outlet of the capture unit to continuously monitor gas composition, transmitting data to a central control unit through a wireless communication protocol, and adjusting the operating parameters of the capture unit; constructing a microenvironment simulator by adjusting the operating parameter information of the capture unit, and using a small-scale automated control platform based on the Internet of Things technology in conjunction with a high-precision sensor to monitor the light intensity, water temperature, and nutrient solution ratio in the Chlorella cultivation environment. The ratio and CO2 concentration are regulated; the tail gas recovery device is designed with a combination of high-efficiency compressors and condensers to separate and recover CO2 that is not completely absorbed, and the CO2 is reintroduced into the culture gas column after treatment. During the process, the fresh CO2 supplement and the reuse ratio of recovered CO2 are dynamically managed; in the microenvironment simulator, the Nannochloropsis algae activates the CO2 concentration mechanism and utilizes photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water into organic matter to obtain Nannochloropsis algae organisms, and when the Nannochloropsis algae reaches the mature stage, a centrifuge is used to collect the mature Nannochloropsis algae in the microenvironment simulator; preliminary conversion experiments and performance evaluations are carried out on the collected Nannochloropsis algae.

[0006] As a further solution of the present invention: a small-scale capture unit based on a miniaturized adsorbent is constructed to capture CO2 from low-flow industrial waste gas, and impurities in CO2 are removed by a portable scrubbing tower to obtain purified CO2. The specific steps are: selecting activated carbon fiber as the adsorbent; designing a compact capture unit, filling the unit with ACF adsorbent, and configuring an airflow distribution system; setting up a portable scrubbing tower to remove harmful impurities such as SOx and NOx in the captured CO2.

[0007] As a further solution of the present invention: the size of the capture unit is designed to be 50 cm long, 30 cm wide and 20 cm high. The portable washing tower adopts a multi-stage spraying device to spray water mist containing alkaline solution, which fully contacts the gas to neutralize and remove the acidic gas. A packing layer is installed in the portable washing tower.

[0008] As a further solution of the present invention: a high-precision gas analyzer and a sensor are deployed at the inlet and outlet of the capture unit to continuously monitor the gas composition, transmit the data to the central control unit through a wireless communication protocol, and adjust the operating parameters of the capture unit. The specific steps are: a high-precision gas analyzer based on infrared absorption spectroscopy technology is installed at the inlet and outlet of the capture unit, and a temperature, pressure, and humidity multi-parameter sensor is configured; the high-precision gas analyzer and the multi-parameter sensor continuously monitor the inlet and outlet gas composition, including CO2 concentration, SOx, and NOx, and transmit the monitored data to the central control unit through the wireless communication protocol LoRa; after receiving the data from the high-precision gas analyzer and the multi-parameter sensor, the central control unit performs real-time processing and storage, and dynamically adjusts the capture unit, including the temperature and pressure, of the capture unit, as expressed by:

[0009]

[0010] Among them, P new is the new operating parameter value, P old is the current operating parameter value, k is the adjustment coefficient, C in is the CO2 concentration entering the capture unit, C target is the target CO2 concentration.

[0011] As a further solution of the present invention: the microenvironment simulator is constructed by adjusting the operating parameter information of the capture unit, and a small-scale automated control platform based on the Internet of Things technology is used in combination with a high-precision sensor to regulate the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Chlorella. The specific steps are: based on the adjusted operating parameters of the capture unit, an optimized high-purity CO2 is obtained, and a microenvironment simulator is constructed; an LED lamp is used as a light source to adjust the spectrum and light intensity according to the needs of Chlorella; a small-scale automated control platform based on the Internet of Things technology is developed in combination with a high-precision sensor to achieve the regulation of the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Chlorella. The expression is:

[0012]

[0013] Among them, S new is the new environmental parameter value, S old is the current environmental parameter value, α is the temperature adjustment coefficient, β is the CO2 concentration adjustment coefficient, P target is the target water temperature, P current is the current water temperature, P max is the maximum allowable water temperature, C target is the target CO2 concentration, C current is the current CO2 concentration, C max is the maximum allowable CO2 concentration.

[0014] As a further solution of the present invention: the exhaust gas recovery device is designed by combining a high-efficiency compressor and a condenser to separate and recover CO2 that has not been completely absorbed, and the CO2 is reintroduced into the culture gas column after treatment. During the process, the fresh CCO2 supplement amount and the reuse ratio of the recovered CO2 are dynamically managed. The specific steps are: in the exhaust gas recovery device, a combination of a high-efficiency compressor and a condenser is selected, and during the compression and condensation process, a multi-stage filter is set to remove particulate matter, moisture and harmful components in the exhaust gas; the gas after compression and condensation enters the liquefaction separation tower, CO2 is liquefied under low temperature and high pressure conditions, separated from other gas components, and the separated liquid CO2 is collected and stored, and reintroduced into the culture gas column; high-precision gas analyzers and sensors are deployed at the inlet and outlet positions of the liquefaction separation tower to continuously monitor the gas composition and transmit the data to the central control unit through a wireless communication protocol; the recovered CO2 will be purified before being reintroduced into the culture gas column to remove residual trace impurities; according to the data received by the central control unit, the amount of CO2 reintroduced into the culture gas column is dynamically adjusted, and the expression is:

[0015]

[0016] Where R is the reuse ratio of recovered CO2, F new is the amount of fresh CO2 added, F total is the total CO2 supply, γ is the adjustment coefficient, C current is the CO2 concentration in the current culture gas column, C target is the target CO2 concentration, C max is the maximum allowable CO2 concentration.

[0017] As a further solution of the present invention: the Nannochloropsis algae is activated in the microenvironment simulator by a CO2 concentration mechanism, and uses photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water into organic matter to obtain the Nannochloropsis algae organism, and when the Nannochloropsis algae reaches a mature stage, a centrifuge is used to collect the mature Nannochloropsis algae in the microenvironment simulator, and the specific steps are: the specific protein on the surface of the Nannochloropsis algae cell actively transports HCO3 in the seawater -After entering the cell, it is rapidly converted into CO2 under the action of carbonic anhydrase and concentrated around the chloroplast, especially near the position of RuBisOO. In the microenvironment simulator, the micro-chlorophyllous algae uses the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body through photosynthesis, and combines light energy to convert the carbon source into organic matter to form the micro-chlorophyllous algae organism. In this process, the photosystem PSII and the photosystem PSI capture the photon energy to generate ATP and NADPH, and then fix CO2 into G3P ​​through the Calvin cycle, and finally synthesize polysaccharides such as glucose, lipids and proteins. The small-scale automatic control platform based on the Internet of Things technology will dynamically adjust the light intensity, water temperature and CO2 concentration according to the real-time monitoring data. The growth of micro-chlorophyllous algae is continuously monitored through high-precision sensors, including cell density and dry weight indicators, to determine whether it has reached the mature stage. Select an efficient centrifuge to collect micro-chlorophyllous algae with a maturity OD750 value between 2 and 3. During the collection process, the collection efficiency of the centrifuge at different time points is optimized, and the expression is:

[0018] C final =C initial ×(1-e -k·t );

[0019] Among them, C final is the final amount of Nannochloropsis collected, C initial is the amount of Nannochloropsis in the initial culture air column, k is the collection efficiency coefficient, and t is the collection time.

[0020] As a further scheme of the present invention: the collected Nannochloropsis algae are subjected to preliminary transformation experiments and performance evaluation, and the specific steps are: first, the dry weight, lipid content and calorific value parameters of the collected Nannochloropsis algae are measured, and the dry weight is determined by a drying method, the lipids are extracted by a Soxhlet extraction method, and the calorific value is determined by combustion analysis; then, the protein content is determined by the Kjeldahl method, the amino acid composition is determined by an amino acid analyzer, and the trace elements are determined by an atomic absorption spectrometer; finally, the polysaccharide content is determined by a chemical reagent method, the pigment content is determined by a spectrophotometer, and the enzyme activity is determined by an enzyme activity assay kit; various evaluation results are obtained, and the culture conditions of Nannochloropsis algae are continuously optimized according to the evaluation results.

[0021] As a further solution of the present invention: the expressions for determining dry weight by drying method, extracting lipid by Soxhlet extraction method, determining calorific value by combustion analysis, determining protein content by Kjeldahl method, determining amino acid composition by amino acid analyzer, and determining trace elements by atomic absorption spectrometry are respectively:

[0022]

[0023] Among them, E fuelis the biofuel energy efficiency, L is the lipid content of Nannochloropsis algae, H is the calorific value of lipids, W is the dry weight of Nannochloropsis algae, V feed is the feed additive value index, P is the protein content, A is the amino acid score, and M is the trace element score.

[0024] As a further solution of the present invention: the polysaccharide content is determined by a chemical reagent method, the pigment content is determined by a spectrophotometer, and the enzyme activity is determined by an enzyme activity determination kit, and the expression is:

[0025]

[0026] Among them, I chem is the applicability index of chemical raw materials, S is the polysaccharide content, C is the pigment content, and E is the enzyme activity.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] By selecting activated carbon fiber as the adsorbent and designing a compact capture unit, efficient capture of CO2 from low-flow industrial waste gas is achieved, which not only significantly improves the CO2 capture efficiency, but also reduces the space occupied by the equipment, making it suitable for laboratory-scale applications. By installing a high-precision gas analyzer based on infrared absorption spectroscopy technology at the inlet and outlet of the capture unit and configuring temperature, pressure, and humidity multi-parameter sensors, real-time monitoring of the inlet and outlet gas composition is achieved. The central control unit dynamically adjusts the operating parameters of the capture unit, including temperature and pressure, according to real-time data to optimize the CO2 capture effect. By adjusting the operating parameters of the capture unit, a microenvironment simulator that can accurately simulate natural conditions is constructed to provide the most suitable growth environment for Chlorella. Using LED lamps as light sources, the spectrum and light intensity can be adjusted according to the needs of Chlorella to maximize its photosynthesis efficiency. Combined with high-precision sensors, a small-scale automated control platform based on the Internet of Things technology is developed to achieve precise control of light intensity, water temperature, nutrient solution ratio and CO2 concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a process flow of a Nannochloropsis algae cultivation method integrating CO2 recovery and reuse. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1

[0034] See also Figure 1 , which is the first embodiment of the present invention, provides a method for cultivating Nannochloropsis spp. integrating CO2 recovery and reuse, comprising:

[0035] S1. Build a small capture unit based on miniaturized adsorbent to capture CO2 from low-flow industrial waste gas, remove impurities in CO2 through a portable scrubber to obtain purified CO2;

[0036] Specifically, a small-scale capture unit based on a miniaturized adsorbent is constructed to capture CO2 from low-flow industrial waste gas, and impurities in CO2 are removed through a portable scrubber to obtain purified CO2. The specific steps are: selecting activated carbon fiber as the adsorbent; designing a compact capture unit, filling the unit with ACF adsorbent, and configuring an air flow distribution system; setting up a portable scrubber to remove harmful impurities such as SOx and NOx in the captured CO2; the size of the capture unit is designed to be 50 cm long, 30 cm wide and 20 cm high, and the portable scrubber adopts a multi-stage spray device to spray water mist containing alkaline solution to fully contact the gas, neutralize and remove acidic gases, and a packing layer is installed in the portable scrubber.

[0037] It should be noted that by selecting activated carbon fiber (ACF) as the adsorbent and designing a compact capture unit, efficient and economical CO2 capture is achieved. This capture unit is not only suitable for low-flow industrial waste gas treatment, but also has a compact design that reduces the footprint and is suitable for use in environments with limited space. The portable scrubber adopts a multi-stage spray device to ensure the effective removal of harmful impurities such as SOx and NOx, thereby improving the purity of CO2. In addition, the combination of the capture unit and the scrubber significantly improves the environmental performance of the system and reduces the impact on the environment.

[0038] S2. Deploy high-precision gas analyzers and sensors at the inlet and outlet of the capture unit to continuously monitor the gas composition, transmit the data to the central control unit through wireless communication protocols, and adjust the operating parameters of the capture unit;

[0039] Specifically, high-precision gas analyzers and sensors are deployed at the inlet and outlet of the capture unit to continuously monitor the gas composition, transmit the data to the central control unit through the wireless communication protocol, and adjust the operating parameters of the capture unit. The specific steps are: install a high-precision gas analyzer based on infrared absorption spectroscopy technology at the inlet and outlet of the capture unit, and configure temperature, pressure, and humidity multi-parameter sensors; the high-precision gas analyzer and multi-parameter sensor continuously monitor the inlet and outlet gas composition, including CO2 concentration, SOx, and NOx, and transmit the monitored data to the central control unit through the wireless communication protocol LoRa; after receiving the data from the high-precision gas analyzer and multi-parameter sensor, the central control unit performs real-time processing and storage, and dynamically adjusts the capture unit, including temperature and pressure, as expressed by:

[0040]

[0041] Among them, P new is the new operating parameter value, P old is the current operating parameter value, k is the adjustment coefficient, C in is the CO2 concentration entering the capture unit, C target is the target CO2 concentration.

[0042] It should be noted that by installing high-precision gas analyzers based on infrared absorption spectroscopy technology at the inlet and outlet of the capture unit and configuring temperature, pressure, and humidity multi-parameter sensors, real-time monitoring of the inlet and outlet gas composition is achieved, ensuring accurate measurement of key parameters such as CO2 concentration, SOx, and NOx. The wireless communication protocol LoRa is used for data transmission, which not only ensures the stability of data transmission, but also enhances the flexibility and scalability of the system. The central control unit dynamically adjusts operating parameters such as temperature and pressure according to real-time data, thereby optimizing the CO2 capture effect and improving the intelligence level and operation efficiency of the system.

[0043] S3. By adjusting the operating parameter information of the capture unit, a microenvironment simulator is constructed, and a small-scale automation control platform based on the Internet of Things technology is used in conjunction with high-precision sensors to control the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Nannochloropsis algae;

[0044] Specifically, by adjusting the operating parameter information of the capture unit, a microenvironment simulator is constructed, and a small-scale automation control platform based on the Internet of Things technology is used in conjunction with high-precision sensors to regulate the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Chlorella. The specific steps are: based on the adjusted operating parameters of the capture unit, the optimized high-purity CO2 is obtained, and a microenvironment simulator is constructed; LED lamps are used as light sources to adjust the spectrum and light intensity according to the needs of Chlorella; combined with high-precision sensors, a small-scale automation control platform based on the Internet of Things technology is developed to achieve the regulation of light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Chlorella. The expression is:

[0045]

[0046] Among them, S new is the new environmental parameter value, S old is the current environmental parameter value, α is the temperature adjustment coefficient, β is the CO2 concentration adjustment coefficient, P target is the target water temperature, P current is the current water temperature, P max is the maximum allowable water temperature, C target is the target CO2 concentration, C current is the current CO2 concentration, C max is the maximum allowable CO2 concentration.

[0047] It should be noted that by adjusting the operating parameters of the capture unit, a microenvironment simulator that can accurately simulate natural conditions was constructed, providing the most suitable growth environment for Nannochloropsis. The application of LED light sources can adjust the spectrum and light intensity according to the needs of Nannochloropsis to maximize its photosynthesis efficiency. Combined with high-precision sensors and a small-scale automated control platform based on Internet of Things technology, precise control of light intensity, water temperature, nutrient solution ratio and CO2 concentration is achieved. The intelligent control method not only improves the growth rate and biomass of Nannochloropsis, but also reduces human intervention, ensuring the accuracy and repeatability of the experimental results, and laying a solid foundation for subsequent large-scale production and application.

[0048] S4. Design the tail gas recovery device by combining high-efficiency compressor and condenser to separate and recover the CO2 that is not completely absorbed, and reintroduce the CO2 into the culture gas column after treatment. In the process, dynamically manage the fresh CO2 replenishment amount and the reuse ratio of the recovered CO2;

[0049] Specifically, a tail gas recovery device is designed by combining a high-efficiency compressor and a condenser to separate and recover CO2 that is not completely absorbed. After treatment, the CO2 is reintroduced into the culture gas column. During the process, the fresh CCO2 supplement amount and the reuse ratio of the recovered CO2 are dynamically managed. The specific steps are as follows: in the tail gas recovery device, a combination of a high-efficiency compressor and a condenser is selected, and during the compression and condensation process, a multi-stage filter is set to remove particulate matter, moisture and harmful components in the tail gas; the gas after compression and condensation enters the liquefaction separation tower, CO2 is liquefied under low temperature and high pressure conditions, separated from other gas components, and the separated liquid CO2 is collected and stored, and reintroduced into the culture gas column; high-precision gas analyzers and sensors are deployed at the inlet and outlet of the liquefaction separation tower to continuously monitor the gas composition and transmit the data to the central control unit through a wireless communication protocol; before the recovered CO2 is reintroduced into the culture gas column, it will be purified to remove residual trace impurities; according to the data received by the central control unit, the amount of CO2 reintroduced into the culture gas column is dynamically adjusted, and the expression is:

[0050]

[0051] Where R is the reuse ratio of recovered CO2, F new is the amount of fresh CO2 added, F total is the total CO2 supply, γ is the adjustment coefficient, C current is the CO2 concentration in the current culture gas column, C target is the target CO2 concentration, C max is the maximum allowable CO2 concentration.

[0052] It should be noted that by designing the exhaust gas recovery device in the form of a combination of high-efficiency compressors and condensers, effective separation and recovery of CO2 that has not been completely absorbed is achieved. The setting of multi-stage filters removes particulate matter, moisture and other harmful components in the exhaust gas, ensuring the quality of the recovered CO2. The compressed and condensed gas enters the liquefaction separation tower, and CO2 is liquefied and separated from other gas components under low temperature and high pressure conditions. The separated liquid CO2 is collected, stored, and reintroduced into the culture gas column. The process not only improves the utilization rate of CO2 and reduces the demand for fresh CO2 replenishment, but also reduces operating costs. The dynamic management of the fresh CO2 replenishment amount and the reuse ratio of recovered CO2 further optimizes the overall performance of the system, realizes the maximum utilization of resources and the improvement of economic benefits, while reducing carbon emissions, meeting the requirements of green development.

[0053] S5, the Nannochloropsis algae in the microenvironment simulator starts the CO2 concentration mechanism, uses photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body into organic matter, thereby obtaining the Nannochloropsis algae organism, and when the Nannochloropsis algae reaches a mature stage, uses a centrifuge to collect the mature Nannochloropsis algae in the microenvironment simulator;

[0054] Specifically, the microenvironment simulator uses photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water into organic matter to obtain the microenvironment simulator. When the microenvironment simulator reaches maturity, the mature microenvironment simulator is collected by a centrifuge. The specific steps are as follows: the specific protein on the surface of the microenvironment simulator actively transports HCO3 in the seawater. - After entering the cell, it is rapidly converted into CO2 under the action of carbonic anhydrase and concentrated around the chloroplast, especially near the position of RuBisCO. In the microenvironment simulator, the micro-chlorophyll algae utilizes the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body through photosynthesis, and combines light energy to convert the carbon source into organic matter to form the micro-chlorophyll algae organism. In this process, the photosystem PSII and the photosystem PSI capture the photon energy to generate ATP and NADPH, and then fix CO2 into G3P ​​through the Calvin cycle, and finally synthesize polysaccharides such as glucose, lipids and proteins. The small-scale automatic control platform based on the Internet of Things technology will dynamically adjust the light intensity, water temperature and CO2 concentration according to the real-time monitoring data. The growth of micro-chlorophyll algae is continuously monitored through high-precision sensors, including cell density and dry weight indicators, to determine whether it has reached the mature stage. Select an efficient centrifuge to collect micro-chlorophyll algae with a maturity OD750 value between 2 and 3. During the collection process, the collection efficiency of the centrifuge at different time points is optimized, and the expression is:

[0055] C final =C initial ×(1-e -k·t );

[0056] Among them, C final is the final amount of Nannochloropsis collected, C initial is the amount of Nannochloropsis in the initial culture air column, k is the collection efficiency coefficient, and t is the collection time.

[0057] It should be noted that specific proteins on the surface of Nannochloropsis cells actively transport HCO3 in seawater. -After entering the cell, it is rapidly converted into CO2 under the action of carbonic anhydrase and concentrated around the chloroplasts, especially near RuBisCO, which not only increases RuBisCO's affinity for CO2, but also reduces the competition of oxygen with it, thereby significantly enhancing the carbon fixation efficiency. In the microenvironment simulator, Nannochloropsis algae utilizes the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body through photosynthesis, and combines light energy to convert these carbon sources into organic matter to form Nannochloropsis algae organisms. In this process, photosystems PSII and PSI capture photon energy to generate ATP and NADPH, and then fix CO2 into G3P ​​through the Calvin cycle. And finally synthesize polysaccharides such as glucose, lipids and proteins. The small-scale automated control platform based on the Internet of Things technology dynamically adjusts the light intensity, water temperature and CO2 concentration according to the real-time monitoring data to ensure that the Nannochloropsis is always in the best growth state. High-precision sensors continuously monitor the growth of Nannochloropsis, including cell density and dry weight indicators, to determine whether it has reached the maturity stage. The use of high-efficiency centrifuges to collect mature Nannochloropsis ensures the efficiency and non-destructiveness of the collection process, and optimizes the collection efficiency of the centrifuge at different time points, which not only improves the harvest rate, but also reduces the loss during the collection process, ensuring the quality and quantity of Nannochloropsis, and providing high-quality materials for subsequent transformation experiments.

[0058] S6. Conduct preliminary transformation experiments and performance evaluation on the collected Nannochloropsis algae;

[0059] Specifically, the collected Nannochloropsis algae were subjected to preliminary transformation experiments and performance evaluation, and the specific steps were as follows: first, the dry weight, lipid content and calorific value key parameters of the collected Nannochloropsis algae were measured, and the dry weight was determined by the drying method, the lipids were extracted by the Soxhlet extraction method, and the calorific value was determined by combustion analysis; then, the protein content was determined by the Kjeldahl nitrogen method, the amino acid composition was determined by the amino acid analyzer, and the trace elements were determined by the atomic absorption spectrometry; finally, the polysaccharide content was determined by the chemical reagent method, the pigment content was determined by the spectrophotometer, and the enzyme activity was determined by the enzyme activity assay kit; various evaluation results were obtained, and the culture conditions of Nannochloropsis algae were continuously optimized according to the evaluation results; the expressions for determining the dry weight by the drying method, extracting the lipids by the Soxhlet extraction method, determining the calorific value by combustion analysis, determining the protein content by the Kjeldahl nitrogen method, determining the amino acid composition by the amino acid analyzer, and determining the trace elements by the atomic absorption spectrometry were as follows:

[0060]

[0061] Among them, E fuel is the biofuel energy efficiency, L is the lipid content of Nannochloropsis algae, H is the calorific value of lipids, W is the dry weight of Nannochloropsis algae, V feedis the feed additive value index, P is the protein content, A is the amino acid score, and M is the trace element score; the polysaccharide content is determined by chemical reagent method, the pigment content is determined by spectrophotometer, and the enzyme activity is determined by enzyme activity assay kit. The expression is:

[0062]

[0063] Among them, I chem is the applicability index of chemical raw materials, S is the polysaccharide content, C is the pigment content, and E is the enzyme activity.

[0064] It should be noted that by conducting preliminary conversion experiments and performance evaluations on the collected Nannochloropsis algae, we can fully understand its application potential in different fields. First, key parameters such as dry weight, lipid content and calorific value of Nannochloropsis algae are measured to evaluate its potential as a biofuel; then, the protein content, amino acid composition and trace elements are determined to evaluate its value as a feed additive; finally, the polysaccharide content, pigment and enzyme activity are determined to evaluate its suitability as a chemical raw material. The results of various evaluations provide a scientific basis for optimizing the culture conditions of Nannochloropsis algae, guide its application direction in different industries, and further enhance the economic and environmental benefits of the system. Through these evaluations, the culture method of Nannochloropsis algae can be continuously improved, its quality and yield can be improved, and the widespread application of Nannochloropsis algae in multiple fields can be promoted.

[0065] Specifically, in order to ensure that Nannochloropsis can grow under optimal conditions, the following specific culture medium formula is selected:

[0066] Filtered seawater: Use 1 L of filtered seawater (passed through a 0.22 μm filter membrane) to which 35 g of sea salt was added to simulate the natural seawater environment;

[0067] Nitrogen source: Add 2 ml of NaNO3 (sodium nitrate) per liter of culture medium to provide the necessary nitrogen element;

[0068] Phosphorus source: Add 2 ml NaHPO3 (disodium hydrogen phosphate) per liter of culture medium to ensure adequate phosphorus supply;

[0069] Metal complex: Add 1 ml of metal complex per liter of culture medium, which contains various trace elements such as iron, manganese, and zinc to support the normal metabolism of Nannochloropsis algae;

[0070] Vitamins: Add 0.5 ml of vitamin mixture per liter of culture medium to promote healthy cell growth.

[0071] It should be noted that all components are mixed under sterile conditions to ensure the cleanliness and biosafety of the culture medium. The culture medium is sterilized at high temperature and high pressure before use to eliminate the possible risk of microbial contamination. By strictly controlling the composition and preparation process of the culture medium, an ideal growth environment is provided for Nannochloropsis, thereby increasing its growth rate and final yield.

[0072] In summary, by selecting activated carbon fiber as the adsorbent and designing a compact capture unit, efficient capture of CO2 from low-flow industrial waste gas is achieved, which not only significantly improves the CO2 capture efficiency, but also reduces the space occupied by the equipment, making it suitable for laboratory-scale applications. By installing a high-precision gas analyzer based on infrared absorption spectroscopy technology at the inlet and outlet of the capture unit and configuring temperature, pressure, and humidity multi-parameter sensors, real-time monitoring of the inlet and outlet gas composition is achieved. The central control unit dynamically adjusts the operating parameters of the capture unit, including temperature and pressure, according to real-time data to optimize the CO2 capture effect. By adjusting the operating parameters of the capture unit, a microenvironment simulator that can accurately simulate natural conditions is constructed to provide the most suitable growth environment for Chlorella. Using LED lamps as light sources, the spectrum and light intensity can be adjusted according to the needs of Chlorella to maximize its photosynthesis efficiency. Combined with high-precision sensors, a small-scale automated control platform based on the Internet of Things technology is developed to achieve precise control of light intensity, water temperature, nutrient solution ratio and CO2 concentration.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse, characterized in that: include: Construct a small capture unit based on miniaturized adsorbent to capture CO2 from low-flow industrial waste gas, remove impurities in CO2 through a portable scrubber to obtain purified CO2; Deploy high-precision gas analyzers and sensors at the inlet and outlet of the capture unit to continuously monitor the gas composition, transmit data to the central control unit through wireless communication protocols, and adjust the operating parameters of the capture unit; By adjusting the operating parameter information of the capture unit, a microenvironment simulator was constructed, and a small-scale automation control platform based on the Internet of Things technology was used in conjunction with high-precision sensors to control the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Nannochloropsis. The tail gas recovery device is designed by combining high-efficiency compressors and condensers to separate and recover the CO2 that has not been completely absorbed. After treatment, the CO2 is reintroduced into the culture gas column. During the process, the fresh CO2 replenishment amount and the reuse ratio of the recovered CO2 are dynamically managed; The Nannochloropsis algae in the microenvironment simulator starts the CO2 concentration mechanism and uses photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body into organic matter to obtain the Nannochloropsis algae organisms. When the Nannochloropsis algae reaches a mature stage, a centrifuge is used to collect the mature Nannochloropsis algae in the microenvironment simulator. The collected Nannochloropsis algae were subjected to preliminary transformation experiments and performance evaluation.

2. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The method of constructing a small-scale capture unit based on a miniaturized adsorbent to capture CO2 from low-flow industrial waste gas, removing impurities in CO2 through a portable scrubber to obtain purified CO2, comprises the following specific steps: Select activated carbon fiber as adsorbent; Design a compact capture unit, fill it with ACF adsorbent, and configure an air flow distribution system; A portable scrubber is installed to remove harmful impurities such as SOx and NOx from the captured CO2.

3. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 2, characterized in that: The size of the capture unit is designed to be 50 cm long, 30 cm wide and 20 cm high. The portable washing tower adopts a multi-stage spraying device to spray water mist containing alkaline solution, which fully contacts the gas to neutralize and remove the acidic gas. A packing layer is installed in the portable washing tower.

4. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The high-precision gas analyzer and sensor are deployed at the inlet and outlet of the capture unit to continuously monitor the gas composition, transmit the data to the central control unit through the wireless communication protocol, and adjust the operating parameters of the capture unit. The specific steps are as follows: A high-precision gas analyzer based on infrared absorption spectroscopy technology is installed at the inlet and outlet of the capture unit, and multi-parameter sensors such as temperature, pressure and humidity are configured; High-precision gas analyzers and multi-parameter sensors continuously monitor the inlet and outlet gas composition, including CO2 concentration, SOx and NOx, and transmit the monitored data to the central control unit via the wireless communication protocol LoRa; After receiving the data from the high-precision gas analyzer and multi-parameter sensor, the central control unit processes and stores them in real time, and dynamically adjusts the capture unit of the capture unit, including temperature and pressure, as expressed by: Among them, P new is the new operating parameter value, P old is the current operating parameter value, k is the adjustment coefficient, C in is the CO2 concentration entering the capture unit, C target is the target CO2 concentration.

5. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The microenvironment simulator is constructed by adjusting the operating parameter information of the capture unit, and a small-scale automation control platform based on the Internet of Things technology is used in conjunction with a high-precision sensor to regulate the light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Nannochloropsis. The specific steps are as follows: Based on the adjusted operating parameters of the capture unit, the optimized high-purity CO2 is obtained and a microenvironment simulator is constructed; Use LED lights as light sources, and adjust the spectrum and light intensity according to the needs of Nannochloropsis algae; Combined with high-precision sensors, a small-scale automated control platform based on the Internet of Things technology was developed to achieve the regulation of light intensity, water temperature, nutrient solution ratio and CO2 concentration in the culture environment of Nannochloropsis algae. The expression is: Among them, S new is the new environmental parameter value, S old is the current environmental parameter value, α is the temperature adjustment coefficient, β is the CO2 concentration adjustment coefficient, P target is the target water temperature, P current is the current water temperature, P max is the maximum allowable water temperature, C target is the target CO2 concentration, C current is the current CO2 concentration, C max is the maximum allowable CO2 concentration.

6. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The tail gas recovery device is designed by combining a high-efficiency compressor and a condenser to separate and recover the CO2 that is not completely absorbed, and reintroduce the CO2 into the culture gas column after treatment. During the process, the fresh CO2 supplement amount and the reuse ratio of the recovered CO2 are dynamically managed. The specific steps are as follows: In the exhaust gas recovery device, a combination of high-efficiency compressors and condensers is selected, and during the compression and condensation process, multi-stage filters are set to remove particulate matter, moisture and harmful components in the exhaust gas; The compressed and condensed gas enters the liquefaction separation tower, where CO2 is liquefied under low temperature and high pressure conditions, separated from other gas components, and the separated liquid CO2 is collected, stored, and reintroduced into the culture gas column; Deploy high-precision gas analyzers and sensors at the inlet and outlet of the liquefaction separation tower to continuously monitor gas composition and transmit data to the central control unit via wireless communication protocols; The recovered CO2 is purified to remove any remaining trace impurities before being reintroduced into the culture gas column; According to the data received by the central control unit, the amount of CO2 reintroduced into the culture gas column is dynamically adjusted, and the expression is: Where R is the reuse ratio of recovered CO2, F new is the amount of fresh CO2 added, F total is the total CO2 supply, γ is the adjustment coefficient, C current is the CO2 concentration in the current culture gas column, C target is the target CO2 concentration, C max is the maximum allowable CO2 concentration.

7. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The Nannochloropsis algae is activated in the microenvironment simulator by a CO2 concentration mechanism, and uses photosynthesis to convert the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water into organic matter to obtain the Nannochloropsis algae organism, and when the Nannochloropsis algae reaches a mature stage, a centrifuge is used to collect the mature Nannochloropsis algae in the microenvironment simulator, and the specific steps are: Specific proteins on the cell surface of Nannochloropsis spp. actively transport water from seawater After entering the cell, it is rapidly converted into CO2 by carbonic anhydrase and concentrated around the chloroplasts, especially near RuBisCO. In the microenvironment simulator, Nannochloropsis algae utilizes the purified CO2 provided by the capture unit and the dissolved inorganic carbon in the water body through photosynthesis, and combines light energy to convert the carbon source into organic matter to form Nannochloropsis algae organisms. In this process, photosystem PSII and photosystem PSI capture photon energy to generate ATP and NADPH, and then fix CO2 into G3P ​​through the Calvin cycle, and finally synthesize polysaccharides such as glucose, lipids and proteins; A small automation control platform based on the Internet of Things technology will dynamically adjust the light intensity, water temperature, and CO2 concentration according to the real-time monitoring data; High-precision sensors are used to continuously monitor the growth of Nannochloropsis algae, including cell density and dry weight, to determine whether it has reached maturity; Select an efficient centrifuge to collect Chlorella with a maturity OD750 value between 2 and 3. During the collection process, optimize the collection efficiency of the centrifuge at different time points. The expression is: C final =C initial ×(1-e -k·t ); Among them, C final is the final amount of Nannochloropsis collected, C initial is the amount of Nannochloropsis in the initial culture air column, k is the collection efficiency coefficient, and t is the collection time.

8. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 1, characterized in that: The preliminary transformation experiment and performance evaluation of the collected Nannochloropsis algae are carried out in the following specific steps: Firstly, the key parameters of dry weight, lipid content and calorific value of the collected Nannochloropsis were measured, and the dry weight was determined by the drying method, the lipids were extracted by Soxhlet extraction, and the calorific value was determined by combustion analysis; Then, protein content was determined using the Kjeldahl method, amino acid composition was determined using an amino acid analyzer, and trace elements were determined using atomic absorption spectrometry; Finally, the polysaccharide content was determined using a chemical reagent method, the pigment content was determined using a spectrophotometer, and the enzyme activity was determined using an enzyme activity assay kit; Obtain various evaluation results and continuously optimize the culture conditions of Nannochloropsis according to the evaluation results.

9. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 8, characterized in that: The expressions for determining dry weight by drying method, extracting lipid by Soxhlet extraction method, determining calorific value by combustion analysis, determining protein content by Kjeldahl method, determining amino acid composition by amino acid analyzer, and determining trace elements by atomic absorption spectrometry are as follows: Among them, E fuel is the biofuel energy efficiency, L is the lipid content of Nannochloropsis algae, H is the calorific value of lipids, W is the dry weight of Nannochloropsis algae, V feed is the feed additive value index, P is the protein content, A is the amino acid score, and M is the trace element score.

10. The method for cultivating Nannochloropsis spp. with integrated CO2 recovery and reuse according to claim 8, characterized in that: The polysaccharide content is determined by a chemical reagent method, the pigment content is determined by a spectrophotometer, and the enzyme activity is determined by an enzyme activity assay kit. The expression is: Among them, I chem is the applicability index of chemical raw materials, S is the polysaccharide content, C is the pigment content, and E is the enzyme activity.

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