Microalgae cultivation device

Abstract

Embodiments of the present invention provide an automated microalgae cultivation device and system for self-cleaning, continuous automated algae cultivation and irradiation optimization. The cultivation device includes a photosynthetic tubular reactor for microalgae cultivation with transparent cleaning particles to scrape off any unwanted particles or components, such as including but not limited to biofilm formation. The tubular reactor has multiple double-walled glass. The inner wall of the tube in the tubular reactor can be coated with a super-hydrophobic coating to avoid biofilm formation or to stick any water dirt or dust particles. Since the cleaning particles are transparent, they do not block any sunlight for photosynthesis in the tubular reactor.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a biological sample cultivation device. More particularly, the present invention relates to a microalgae cultivation device for making algal cultivation industrial scale. BACKGROUND

[0002] For decades, the depletion of fossil fuels and the greenhouse effect have been a concern for mankind. Scientists continue to search for environmentally friendly renewable fuels and other new energy sources to solve this pressing problem. Algae-based fuels are classified as the third to fourth generation of renewable fuels due to the difficulty of scaling up cultivation facilities, high cost of fertilizers and dehydration. Algae fuel scientists often choose open ponds to reduce the indirect cost of large-scale cultivation. However, due to cross-contamination and increased biodiversity, productivity is significantly reduced.

[0003] Algae-based biofuels are technically and economically viable and cost-competitive, do not require additional land, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to low biomass concentration and expensive downstream processes.

[0004] Therefore, there is a need for a high-efficiency closed cultivation system that can be continuously cultivated with low energy consumption.

[0005] OBJECT OF THE INVENTION

[0006] It is an object of the present invention to provide a high-efficiency closed cultivation system.

[0007] It is an object of the present invention to allow continuous cultivation.

[0008] It is an object of the present invention to optimize the use of fertilizers, which can be the best way to make algal cultivation industrial scale.

[0009] In addition, it is an object of the present invention to optimize irradiation while closed cultivation.

[0010] It is a further object of the present invention to avoid biofilm formation while algal cultivation.

[0011] It is yet another object of the present invention to prevent cross-contamination and increased biodiversity from initial cultivation to harvesting.

[0012] For further elucidation of the advantages and features of the present invention, a more detailed description of the invention will be provided by referring to its specific embodiments, which are illustrated in the accompanying drawings. It should be understood that these drawings merely depict typical embodiments of the invention and therefore should not be considered limiting of its scope. SUMMARY

[0013] One aspect of the present invention provides an automated algal cultivation system comprising at least one optically transparent photobioreactor tube for performing algal cultivation, wherein the walls of the tube are transparent to avoid blocking sunlight and are coated with a superhydrophobic coating to avoid biofilm formation, and wherein the walls of the tube are made of a transparent material, including at least one or both of bismuth silicate glass or polymethyl methacrylate (PMMA), and wherein the superhydrophobic coating is at least a polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA solution; cleaning particles coated with cationic silica nanoparticles (CNP) to scrape off unwanted particles including biofilm, wherein the cleaning particles run with the water or liquid flow into the tube to scrape off biofilm within the tube; a plurality of LED lights installed around the tube for providing LED light for the algal cultivation at night; a plurality of computer-controlled solar panels installed around the tube for collecting solar energy during the day and providing electrical energy to power the plurality of LED lights at night; and a dewatering device connected to the tube for harvesting cultivated algae from the tube and for separating biomass from the cultivated algae; and wherein, from initial cultivation in the tube to harvesting with the dewatering device, the automated algal cultivation system operates in a closed system to prevent cross-contamination and ecosystem diversification, and wherein the automated algal cultivation system is a self-cleaning system due to the CNP-coated cleaning particles, and wherein the automated algal cultivation system operates continuously for 24 hours, cultivating algae using sunlight during the day and using the LED light at night.

[0014] Embodiments of the cultivation system include a plurality of the tubes arranged horizontally one next to another, or stacked vertically one on top of another, or a combination thereof.

[0015] Embodiments of the cultivation system, the cleaning particles have different densities or the same density, wherein the cleaning particles include at least three types of polymeric particles including linear low-density polyethylene (LLDPE) 0.94 g / ml, styrene-butadiene copolymer 1.01 g / ml, and methyl methacrylate-styrene copolymer 1.08 g / ml, and wherein the size of the polymeric particles ranges between 3 mm - 5 mm in diameter, and wherein the cleaning particles clean the entire inner surface of the walls of the tube and also clean the entire inner surface of the walls of a reservoir storing algae for cultivation.

[0016] In other embodiments of the said cultivation system coated with cationic silica nanoparticles (CNP) the diameter of the said nanoparticles ranges from 50-200 nm, and wherein the said cultivation system coated with cationic silica nanoparticles (CNP) has cationic acrylate polymers with length ranging from 1.8 nm - 2.3 nm.

[0017] Embodiments of the said cultivation system further include one or more heat exchange devices to maintain the temperature of the said automated algal cultivation system in the range of 15°C to 30°C, which is the temperature range to maintain the optimal productivity of the said algae.

[0018] Other embodiments of the said cultivation system include, the said tubular reactor is built from double walled glass with vacuum in between, and wherein the vacuum between the double walled glass of the said tubular reactor acts as an insulator, and wherein the outer and inner diameter of the outer tube in the said double walled glass are 0.08 m and 0.076 m respectively; and wherein the outer and inner diameter of the inner tube in the said double walled glass are 0.05 m and 0.046 m respectively; and wherein the said outer and inner tubes are each built 8 m long, 10 loops per cultivation system in horizontal arrangement of the said tubular reactor, and 7 loops per cultivation system in vertical arrangement of the said tubular reactor to minimize the total energy consumption; and wherein the said outer and inner tubes are separated by 0.05 m due to 180 degree bend after next loop, and wherein the circulation of the algal cultivation in the said tubular reactor is maintained at a maximum flow rate of 0.6 m / s.

[0019] Yet other embodiments of the automated algal culture system further include an algal culture reservoir, and wherein the algal culture reservoir is built from a cylindrical tank and occupies 30% of the total volume of the algal culture system, and wherein the algal culture reservoir further includes one or more built-in sensors, including sensors for monitoring and measuring pH, turbidity, dissolved oxygen, chemicals, water level, and flow; a control panel that manages the flow of algae into the tubular reactor and the flow of sterile water and other sterile liquids in and out of the tubular reactor; an air blower located at the top of the culture system, and one or more pumps for controlling the flow of algae into the tubular reactor and the flow of sterile water and other sterile liquids in and out of the tubular reactor; a set of mirrors for directing sunlight towards the tubular reactor to increase photosynthesis, wherein the set of mirrors includes at least two semi-transparent mirrors placed at an angle of 45° from the ground on the east and west sides of the tubular reactor, and at least one regular mirror placed on the ground directly below the tubular reactor, and wherein the reflective surfaces of the semi-transparent mirrors and the regular mirror face inward, towards the tubular reactor, and wherein the combination of the semi-transparent mirrors and the regular mirror gather more sunlight around the tubular reactor and reflect it uniformly to the walls of the tubular reactor and the algae inside the tubular reactor for uniform light intensity, resulting in increased photosynthetic efficiency.

[0020] In embodiments, the plurality of computer-controlled solar panels for collecting solar energy, wherein the solar panels include at least two solar panels mounted on the east and west sides, and at least one solar panel mounted on the ground directly below the tubular reactor, and wherein the set of solar panels are controlled by computer-controlled motors to move them from the ground at an angle of up to 90° relative to the ground, and wherein the set of solar panels face inward, towards the tubular reactor; and wherein the culture system further includes other devices, including a chemical feeder, a water feeder, and a recirculated medium feeder.

[0021] Embodiments of the culture system include that the air blower pumps external air into the algal culture reservoir, ejects through a plurality of holes present in the front cover of the air blower, and then the air passes through a fiberglass filter and a mangosteen filter of the air blower before entering the culture system, and the mangosteen filter is used to better filter bacteria and other invaders, especially other algal strains.

[0022] Embodiments of the culture system include that the at least one solar panel mounted on the ground directly below the tubular reactor is fixed. BRIEF DESCRIPTION OF DRAWINGS

[0023] For a better understanding of the embodiments of the systems and methods described herein, and to show more clearly how they can be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which like numerals designate like elements / components throughout the drawings, and in which:

[0024] Figures 1-9 Different components included in the cultivation system according to embodiments of the present application are illustrated, as well as an exemplary block diagram of the cultivation system.

[0025] Figure 1 An exemplary view of a tubular reactor included in the cultivation system according to embodiments of the present application is illustrated;

[0026] Figure 2 An exemplary view of a tubular reactor included in the cultivation system according to embodiments of the present application with cleaning particles running inside the tubular reactor is illustrated;

[0027] Figure 3 Cleaning particles coated with cationic silica nanoparticles (abbreviated as CNP) according to embodiments of the present application are illustrated;

[0028] Figure 4 An exemplary view of cleaning particles coated with cationic silica nanoparticles removing biofilm from the surface of a tubular reactor according to embodiments of the present application is illustrated;

[0029] Figure 5 An exemplary block diagram of a cultivation system that can be a vertical or horizontal tubular system according to embodiments of the present application is illustrated;

[0030] Figure 6 An exemplary diagram of an air blower for use in the cultivation system 100 according to embodiments of the present application is illustrated;

[0031] Figure 7 An exemplary mirror model of a mirror set installed in the cultivation system according to embodiments of the present application is illustrated;

[0032] Figure 8 An exemplary solar panel model of a solar panel set installed in the cultivation system according to embodiments of the present application is illustrated; and

[0033] Figure 9 An exemplary implementation model of the cultivation system according to embodiments of the present application is illustrated. DETAILED DESCRIPTION

[0034] This patent describes subject matter for which a patent is desired. The description itself is not intended to limit the scope of this patent. The principles described herein can be embodied in many different forms.

[0035] Illustrative embodiments of the application are described below in the context of a few embodiments and with reference to the accompanying drawings, of which several but not all embodiments of the application are shown. Indeed, the application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout.

[0036] The present application provides a microalgae cultivation device and system for self-cleaning, continuous automatic algae cultivation and irradiation optimization. The cultivation device comprises a photosynthetic tubular reactor for microalgae cultivation with transparent cleaning particles to scrape off any unwanted particles or components, such as the formation of biofilm, including but not limited to. The tubular reactor has multiple double-walled glass. The inner wall of the tube in the tubular reactor can be coated with a superhydrophobic coating to avoid biofilm formation or adhere any water dirt or dust particles. Since the cleaning particles are transparent, they do not block any sunlight for photosynthesis in the tubular reactor.

[0037] In embodiments, the cultivation device comprises multiple double-walled bismuth silicate glass and / or PMMA tubular reactors, cation-coated cleaning particles and other mechanical devices. To avoid biofilm formation, a superhydrophobic coating is applied to the surface of the inner tube. In addition, three types of transparent polymer particles with different densities are used to run along the flow to scrape off any biofilm. Since the cleaning particles are transparent, sunlight is not blocked inside the tubular reactor during cultivation, thus not affecting the photosynthesis of the culture. These cleaning particles with an additional cationic nanoparticle coating are positively charged, which keeps the repulsion from the surface of the biofilm (extracellular polymeric matrix) to a minimum. Therefore, they can easily scrape off the biofilm built on the surface of the inner tube surface. Since the biofilm cannot accumulate in a relatively short period of time, the manual cleaning process does not need to be so frequent. Therefore, the cultivation system can maintain optimal productivity.

[0038] From initial cultivation to harvesting, the present application operates in a closed system with a centrifugal device for separating biomass from the algal mixture to prevent cross-contamination as well as an increase in biological diversity. Therefore, the nutrients in the culture medium can be recycled without being contaminated during operation. In addition, fixed mirrors and solar panels are introduced to increase photosynthetic efficiency and reduce energy costs.

[0039] Reference Figures 1-9, different components included in the cultivation system and the device according to embodiments of the present application are explained along with an exemplary block diagram of the cultivation system. In Figures 1-9 The cultivation system is denoted by reference numeral 100.

[0040] As mentioned above, the cultivation system 100 includes a photosynthetic tubular reactor 102. The tubular reactor 102 provides a device for microalgae cultivation therein. The walls of the tubular reactor 102 are transparent, thus sunlight required for photosynthesis is not blocked and continuous cultivation can be carried out.

[0041] Sufficient irradiance is crucial for algal cultivation. The productivity of algae depends largely on irradiance. Therefore, optically transparent tubular reactor 102 is required. The material used for making the walls of the tubular reactor 102 should be highly transparent to allow sunlight to pass through them.

[0042] In embodiments, bismuth silicate glass and / or PMMA is chosen because of its high transparency, high light transmittance up to 98.5% (97.5% at 380 to 720 nm), salt tolerance, pH fluctuation tolerance, weather condition tolerance, corrosion resistance, chemical resistance, and non-breakability. It would be understood by a person of ordinary skill in the art that the walls of the tubular reactor 102 can be made of any other suitable transparent material other than bismuth silicate glass and / or PMMA without departing from the spirit and scope of the present application.

[0043] Biofilm rapidly accumulates on the surface of the inner tube during cultivation due to surface roughness and hydrophobicity. Excessive amount of biofilm can induce severe disease in the algal culture, eventually leading to decreased productivity. Therefore, the inner tube of the tubular reactor needs to be cleaned regularly to maintain a healthy algal culture. Therefore, in the present tubular reactor 102, bismuth silicate glass and / or PMMA coated with polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA solution produces an extremely smooth and hydrophobic surface, which significantly slows down biofilm accumulation, according to embodiments. It would be understood by a person of ordinary skill in the art that the tube walls of the tubular reactor 102 can be coated with any other suitable material other than polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA to produce a smooth and hydrophobic surface without departing from the spirit and scope of the present application.

[0044] The polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA coating greatly reduces the surface roughness, optimizing the photosynthesis rate and productivity with enhanced light transmission.

[0045] Further, the cultivation system 100 also includes cleaning particles 104 to scrape off any unwanted particles or components, such as formation of biofilm, including but not limited to. The cleaning particles 104 run with the flow within the tubular reactor 102. The cultivation system 100 can have different or same types of cleaning particles 104. For example, different or same density of cleaning particles 104 is used in the cultivation system 100. Cleaning particles 104 having a density range from lower to higher but close to the density of the culture medium can be uniformly distributed along the flow throughout the system 100. Thus, the entire inner surface of the tubular reactor 102 can be cleaned by these cleaning particles 104.

[0046] In an embodiment, three types of polymer particles having a size of 3-5 mm in diameter are selected: linear low density polyethylene (LLDPE) 0.94 g / ml, styrene-butadiene copolymer 1.01 g / ml, and methyl methacrylate-styrene copolymer 1.08 g / ml as cleaning particles 104 to run along the culture flow in the tubular reactor 102. Figure 2 ) These cleaning particles 104 are coated with cationic silica nanoparticles 112 (abbreviated as CNP) Figure 3 ) The CNP 112 coated cleaning particles 104 exhibit good elasticity and transparency. Since these cleaning particles 104 are positively charged, the repulsive force between the biofilm formation surface (116) and the cleaning particles 104 is significantly reduced Figure 4 ) These cleaning particles 104 randomly contact the surface of the inner tube of the tubular reactor 102, scraping off the extracellular polymers before they can start accumulating as biofilm 116 or any already accumulated biofilm. Thus, the entire inner surface of the tubular reactor 102 and the reservoir can be cleaned by these CNP 112 coated cleaning particles 104.

[0047] In an embodiment, in the cationic silica nanoparticles 112, the diameter of the nanoparticles ranges from 50-200 nm. In an embodiment, the cationic silica nanoparticles 112 have a cationic acrylate polymer 114 having a length ranging from 1.8 nm-2.3 nm, and in the molecular representation, “n” is 1. Further, the cationic polymer 114 derivatives in Table 1 are selected and formulated for CNP production. As shown in Table 1, the cationic acrylate coated nanoparticles exhibit the best elasticity and transparency. However, the other two cationic polymers can also be used for the same purpose. A person of ordinary skill in the art can understand that the cationic acrylate polymer 114 can be any suitable polymer for providing elasticity and transparency without departing from the spirit and scope of the present invention.

[0048] Table 1

[0049]

[0050]

[0051] In embodiments, the coating procedure for the cleaning particles 104 includes one or more of the following steps:

[0052] Inspection: Check the condition of the target substrate. Ensure that the transparent polymer particles are in a coating-ready state. 1. Size between 3 to 5 mm in diameter; 2. The substrate surface must be well polished; 3. The material and surface have no visible pores or haze.

[0053] Cleaning: Clean the substrate surface in a deionized water bath using a multi-stage ultrasonic cleaner at 65 degrees Celsius for 1 hour. Ensure that there are no environmentally harmful additives in the substrate holder and stainless steel wire mesh tray.

[0054] Pre-treatment: After cleaning, the substrate is placed in a degassing vacuum oven to eliminate residues and remove porosity with micro-spraying.

[0055] Surface functionalization: The substrate surface is sprayed with an oxygen plasma at 30W 0.2 Torr for 60 minutes to ensure complete oxidation of the substrate surface.

[0056] Loading: Ensure the substrate holder and defined arrangement with reproducible precision. Immerse the substrate in an ethanol solution with 0.01 M TESPA for 18 hours. Then place the substrate in a deionized water bath for ultrasonic treatment for 30 minutes. Dry the substrate with compressed air before proceeding to the next step.

[0057] Coating: Immerse the substrate in a 1.0 wt% (CNP) ethanol solution for 10 seconds. Pull the substrate at 0.50 to 0.75 mm per second. Allow the treated substrate to dry completely in a nitrogen-filled chamber for 1 hour. Repeat the procedure in a 0.8 wt% and then in a 0.5 wt% (CNP) ethanol solution.

[0058] Hydrophobization: Place the coated substrate in an oven at 90 degrees Celsius for 4 hours. Then treat it with an oxygen plasma at 30W 0.3 Torr for 60 seconds. Then transfer the treated substrate to a dry chamber filled with perfluorosilane to ensure stable adhesion between the CNP and the substrate.

[0059] In embodiments, the coating procedure for the tube reactor 102 includes one or more of the following steps:

[0060] Inspection: Check the quantity, material, and surface condition of the target substrate (tube reactor tube 102).

[0061] Cleaning: Clean the substrate surface in a deionized water bath using a multi-stage ultrasonic cleaner.

[0062] Pre-treatment: The cleaned substrate is placed in a degassing vacuum oven to eliminate residues and remove porosity with micro- jets.

[0063] Loading: The substrate holder and defined arrangement are ensured with reproducible accuracy. The substrate is coated with a 5 to 50 micrometer thick polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA mixture in tetrahydrofuran (THF) solution. The ratio of the solution is: (1 : 1 : 23) polydimethylsiloxane / poly(methyl methacrylate) / tetrahydrofuran. It is then heated to 120 degrees Celsius for 60 seconds. The substrate is then placed in an isopropyl alcohol aluminum vapor chamber for 10 seconds.

[0064] The substrate is then transferred to a nitrogen filled chamber to cool to room temperature. The substrate is then coated with a 0.3 micrometer fluorine doped tin oxide polycrystalline layer.

[0065] After the coated substrate cools to room temperature, it is immersed in a 0.2 moles / liter bismuth neodecanoate and 0.2 moles / liter di-tert-butoxydiacetoxysilane ethanol solution at room temperature for 24 hours.

[0066] The substrate is then placed in a 70 degrees Celsius oven for 3 hours and then at 600 degrees Celsius for 15 minutes.

[0067] Finally, after the coated substrate cools to room temperature, it is placed in an ultrasonic bath of 1% hydrofluoric acid and 99% water for 30 minutes.

[0068] The treated substrate is allowed to dry completely in a nitrogen filled environment to ensure stability.

[0069] The cultivation system 100 can include more than one tubular reactor 102, which are arranged horizontally one next to the other, or are vertically stacked one on top of the other. Furthermore, it is preferable to maintain the algae between 15°C and 30°C for optimal productivity. Therefore, the cultivation system 100 can include one or more heat exchange devices (not shown in the figures) installed in the stripper to maintain the temperature of the system 100 in this range. However, heating and cooling the entire system requires a large amount of energy. To reduce this energy consumption, the tubular reactor 102 is built from double-walled glass (106 and 108) with a vacuum between them. Figure 2 ).

[0070] In embodiments, the outer diameter and inner diameter of outer tube 106 are 0.08 m and 0.076 m. In embodiments, the outer diameter and inner diameter of inner tube 108 are 0.05 m and 0.046 m. An inner tube 108 with an inner diameter less than 0.046 m results in a higher pressure for the culture circulation, which results in higher energy consumption. On the other hand, a diameter exceeding 0.1 m reduces the biomass concentration, which increases the dewatering machine input, thus increasing the overall operating cost. Therefore, the inner diameter of inner tube 108 is kept between 0.046 m and 0.1 m. Furthermore, the collected solar energy powers the LED lights 110 during the night to maintain the photosynthetic rate without additional operating costs.

[0071] The vacuum between the glass walls (106 and 108) of the tube reactor 102 acts as an insulator. Therefore, external temperature changes will have a much smaller effect on the culture medium inside the tube reactor 102. As a result, much smaller system heating and cooling are required, resulting in much smaller energy consumption. In embodiments, the tubes are each built 8 m long, 10 loops per system horizontally, and 7 loops per system vertically, to minimize the total energy consumption. In embodiments, both the vertical and horizontal systems are built 0.4 meters above the ground to avoid contamination from rain or floods. In embodiments, each tube is separated by 0.05 m due to a 180-degree bend after the next loop. In embodiments, the circulation of the algae culture is kept at a maximum flow rate of 0.6 m / s.

[0072] Figure 5 is an exemplary block diagram of a cultivation system 100, which can be a vertical or horizontal tube system. As Figure 5 shown, the cultivation system 100 includes one or more mechanical, electrical, electronic, and / or electromechanical components or devices, such as including but not limited to sensors, pumps, control panels, reservoirs, air blowers, air filters, water filters, a set of mirrors, centrifugation devices, solar panels, solar panel controllers, and the like.

[0073] As Figure 5 shown, the cultivation system 100 includes a tube reactor 102 with running clean particles 104 for microalgae cultivation. From initial cultivation to harvesting, the cultivation system 100 operates in a strictly closed system with centrifugation and dewatering devices 118 for separating the biomass from the algae mixture to prevent cross-contamination and ecosystem diversification. The centrifugation and dewatering devices 118 are one of the devices described in U.S. Patent No. US9539525B2, owned by Petroleum 2.0 Ltd. The closed system 100 with low-energy dewatering devices 118 keeps the cultivation strictly closed from initial cultivation to harvesting, which avoids cross-contamination and ecosystem diversification.

[0074] The cultivation system 100 further includes a reservoir and control panel 120, which manages the flow and other functions of the cultivation system 100. The cultivation system 100 further includes an air blower 122 located at the top of the system 100. In embodiments, the air blower 122 is located at a height of 2.2 m to avoid shading issues. The cultivation system 100 also includes a pump 124 that controls the water flow.

[0075] In embodiments, the reservoir 120 is built from a cylindrical tank. It occupies 30% of the total volume of the cultivation system. It has various built-in sensors, including but not limited to sensors for pH, turbidity, dissolved oxygen, chemicals, water level, and flow. The cultivation system 100 can also include other devices, such as including but not limited to a chemical feeder, a water feeder, a recirculated media feeder, the air blower 122, and an air outlet valve. Each sensor works as follows:

[0076] The pH sensor keeps track of the pH value. The chemical feeder gradually feeds into the system to maintain the pH value, for example, in the range between 7 and 8.

[0077] The turbidity sensor keeps track of the algae culture concentration in the system. It provides an estimated harvest time.

[0078] The dissolved oxygen sensor keeps track of the oxygen level, ensuring that it never exceeds a pre-specified level, such as 300% in the media. The air blower 122 is turned on at different speeds depending on the oxygen level.

[0079] The chemical sensor detects the concentration of nitrogen, phosphorus, potassium, and other essential nutrients. The chemical feeder feeds the various nutrients to maintain the concentration at the desired level.

[0080] The water level sensor ensures that the water level is always maintained above a pre-specified level, such as 50% of the reservoir 120. The collection pump 124 stops until the water feeder or the recirculated media feeder brings the water back to the default level.

[0081] The circulation pump 124 is controlled by a flow sensor to maintain the flow rate below a pre-specified maximum level, for example, 0.6 m / s.

[0082] The air outlet valve in the air blower 122 is placed at the top of the tubular system 100 to prevent accumulated air pressure.

[0083] Figure 6An exemplary diagram 600 of an air blower 122 for the cultivation system 100 according to embodiments of the present application is illustrated. The air blower 122 pumps external air into the reservoir 120, which is ejected from the bottom through a plurality of holes present in the front cover 602. The size of the holes can be, for example, 1 mm. The air passes through a glass fiber filter 604 and a mangosteen filter 606 before entering the system 100. The size of the glass fiber filter 604 can be, for example, 30 mm, while the size of the mangosteen filter 606 is, for example, 20 mm.

[0084] The mangosteen filter 606 is used in the cultivation system 100 to better filter bacteria and other intruders, especially other algal strains. The bacteria filtration efficiency is maintained up to 97.8% for particles of 3 microns in diameter (the antibacterial properties of mangosteen have been patented previously with patent code WO2013036210A1). In addition, in embodiments, a spacer 608 can be installed between the glass fiber filter 604 and the mangosteen filter 606 in the air blower 122.

[0085] The cultivation system 100 can also include a set of mirrors for directing sunlight to the tubular reactors 102 to increase photosynthesis. Figure 7 An exemplary mirror model 700 of a set of mirrors installed in the cultivation system 100 according to embodiments of the present application is illustrated. In embodiments, the tubular reactors 102 are vertically stacked on top of each other and their walls face north-south to reduce the shading effect. A semi-transparent mirror 702 is set at a suitable inclination, for example, at an angle of 45° to the ground on the east and west sides of the tubular reactors 102. Regular mirrors 704 are set on the ground directly below the reactors 102. The reflective surfaces of the semi-transparent mirror 702 and the regular mirrors 704 face inwards, towards the tubular reactors 102. The combination of the semi-transparent mirror 702 and the regular mirrors 704 concentrates more sunlight around the tubular reactors 102 and reflects it uniformly to the tubes of the tubular reactors 102. As a result, the algae inside the tubular reactors 102 receive a uniform light intensity, which increases the photosynthetic efficiency.

[0086] The cultivation system 100 also includes computer-controlled solar panels for harvesting solar energy. Figure 8An exemplary solar panel model 800 of a solar panel set installed in the cultivation system 100 according to embodiments of the application is illustrated. In embodiments, the tubular reactors 102 are vertically stacked one on top of the other and their walls face north-south to reduce the shading effect. In embodiments, two solar panels 802 are installed on the east and west sides, and one solar panel 804 is installed on the ground directly below the tubular reactors 102. The solar panel 804 below the reactors 102 is stationary. The side solar panels 802 are controlled by motors so that they can be raised from the ground at an angle of inclination (e.g., up to 90° relative to the ground). These solar panels (802 and 804) face inwards, towards the reactors 102.

[0087] The solar panels 802 and 804 are automatically controlled by the computing control panel 120. According to an exemplary scenario, the angle of elevation is set by the control panel 120 so that the east side panel 802 lies flat on the ground during sunrise, while the west side panel 802 stands at 90° from the ground. Then the east side panel is gradually raised while the west side panel is lowered throughout the day. At noon, both panels (802 and 804) are inclined at 45° from the ground. And at sunset, the east side panel stands at 90° from the ground, while the west side panel lies flat.

[0088] The solar panels 802 and 804 convert sunlight into electricity, which can power the motors that control the panels. Excess electricity can be stored in a battery to power the LEDs 110 Figure 2 installed on the reactor tubes 102 during the night, when there is no sunlight. In combination with the sunlight during the day and the LEDs 110 light at night, the algal culture can undergo the process of photosynthesis for up to 18 hours a day (the optimal daily photosynthesis time). Advantageously, the solar panels 802 and 804 can also act as partial mirrors that reflect the portion of sunlight that is not absorbed by the solar panels 802 and 804. The reflected sunlight is distributed evenly over the tubes of the reactors 102, so that the algae inside will receive uniform light intensity, and thus will increase the photosynthetic efficiency.

[0089] Figure 9 An exemplary implementation model 900 of the cultivation system 100 according to embodiments of the application is illustrated. The implementation model 900 of the cultivation system 100 includes a plurality of tubular reactors 102. The plurality of tubular reactors 102 can be arranged horizontally or vertically or a combination thereof. Further in Figure 9 the implementation model 900, the cultivation system 100 includes a temporary algal culture reservoir 902 for temporarily storing microalgae; a sterile liquid tank 904 for storing sterile liquid; a sterile water tank 906 for storing sterile water; a dehydration device 118, and a reservoir 120 for the algae.

[0090] The goal of the automated algae cultivation system 100 is to run continuously 24 hours a day. In an embodiment, the automated algae cultivation system 100 consists of two separate stages: a cultivation stage and a harvesting stage managed by a series of instruments and machines connected to a PLC system. The purpose of the PLC system is to monitor the instrument readings and control the behavior of the machines by providing corresponding recipe signals once the instrument readings reach specific conditions. In addition, all relevant instrument reading data and command transaction data are captured for process evaluation, data analysis, and troubleshooting purposes.

[0091] The sterile water and liquid can be pumped into and out of the tubular reactor using the sterile water tank 906 and the sterile liquid tank 904, respectively, through one or more pumps, such as the circulation pump 124.

[0092] The tubular reactor 102 is fed with microalgae from the reservoir 120, continuously cultivated into the coated tubular reactor 102 using photosynthesis of the sunlight during the day and the LED light during the night, with clean granules 104 running into the tubular reactor 102 to avoid biofilm formation. After cultivation, the microalgae are harvested and brought into the dewatering and centrifugation device 118 to separate the biomass from the algae mixture. From the initial cultivation to the harvesting, the centrifugation and dewatering device 118 keeps the cultivation strictly closed, which avoids cross-contamination and ecosystem diversification.

[0093] In both the cultivation stage and the harvesting stage, one or more sensor instruments are installed for recording one or more measurement units. In an embodiment, the sensor instruments and machines installed in the cultivation stage (SYS-R1.1 to SYS-R1.11) are shown in Table 2, and the sensor instruments and machines installed in the cultivation stage are managed and run separately. Unless two or more devices / units are interconnected, each device / unit No will affect other devices / units.

[0094] Table 2

[0095]

[0096]

[0097] In an embodiment, the sensor instruments and machines installed in the harvesting stage (SYS-2.1 to SYS-R2.5) are shown in Table 3, and the sensor instruments and machines installed in the harvesting stage are managed and run in sequence. Each device / unit in the harvesting stage must be completed accordingly in order to move to the next device / unit until the harvesting cycle is completed.

[0098] Table 3

[0099]

[0100]

[0101] In an embodiment, for the AAC system, the PLC system carries out functions that follow the system requirements as shown in Table 4:

[0102] Table 4

[0103]

[0104] Advantageously, the coated tubular system 100 having a coated tubular reactor 102 with CNP coated clean particles 104 prevents biofilm accumulation. The self-cleaning system and biofilm free environment allow continuous healthy cultivation without any interruption. Moreover, from initial cultivation to harvesting, the closed system having a low energy consumption dewatering device 118 keeps the cultivation strictly closed, which avoids cross-contamination and ecosystem diversification. It is ensured that the culture medium is recycled without being contaminated.

[0105] Furthermore, due to the installation of solar panels, the cultivation system operates continuously for 24 hours during the day and night. During the day, sunlight promotes photosynthesis. The solar panels charge the LEDs installed on the tubular reactor, which work during the night to perform photosynthesis during the night. Thus, the cultivation system operates continuously for 24 hours.

[0106] In recent years, the low productivity of open pond cultivation due to the increase in biodiversity and cross-contamination has frustrated many algal scientists. Open pond systems have led industrialization to a dead end. The self-cleaning and continuous automated closed cultivation system as described in this application not only avoids time-consuming cleaning processes, which reduce overall productivity, but most importantly, this type of system can be scaled up to a large enough size to reduce operating costs to far below open systems; thus, cross-contamination and ecosystem diversification can be completely avoided. In this strictly closed cultivation system, fertilizer consumption is optimized on a recycling basis without being contaminated. Moreover, harvesting solar energy powers the LED lights during the night to maintain the photosynthetic rate without additional operating costs.

[0107] The present disclosure and examples are intended to be taken only by way of example. Although the present disclosure includes examples from semiconductor chips or components, as those skilled in the art will appreciate, the PCB bridge architecture disclosed herein can be used in a variety of applications. References to devices and architectures used herein are intended to apply to or extend to a larger range and should not be interpreted as limiting the scope and practice of the invention.

Claims

1. An automated algae cultivation system, comprising: At least one optically transparent tubular reactor for algal cultivation, wherein the walls of the tubular reactor are transparent to avoid blocking sunlight and are coated with a superhydrophobic coating to prevent biofilm formation, and The walls of the tubular reactor are made of a transparent material, including at least one or both of bismuth silicate glass and polymethyl methacrylate (PMMA), and the superhydrophobic coating is at least a polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA solution. Cleaning particles coated with cationic silica nanoparticles (CNP) to scrape off unwanted particles, including biofilms, wherein the cleaning particles are carried within the tubular reactor along with a flow of water or liquid entering the tubular reactor to scrape off the biofilm. Multiple LED lights are installed around the tubular reactor to provide LED light for the nighttime algae cultivation; Multiple computer-controlled solar panels are installed around the tubular reactor to collect solar energy during the day and provide electricity at night to power the multiple LED lights; as well as A dehydration device, connected to the tubular reactor, is used to harvest cultured algae from the tubular reactor and to separate biomass from the cultured algae; and The automated algae cultivation system operates in a closed system, from initial cultivation in the tubular reactor to harvesting using the dehydration device, to prevent cross-contamination and ecosystem diversification. Due to the cleaning particles coated with CNP, the automated algae cultivation system is a self-cleaning system, and The automated algae cultivation system operates continuously for 24 hours, using sunlight during the day and LED light at night to cultivate algae.

2. The system according to claim 1, wherein, The system comprises multiple tubular reactors arranged horizontally next to each other, or stacked vertically on top of each other, or arranged in combination.

3. The system according to claim 1, wherein, The cleaning particles may have different or the same density.

4. The system according to claim 3, wherein, The cleaning particles comprise at least three types of polymer particles, including 0.94 g / ml linear low-density polyethylene (LLDPE), 1.01 g / ml styrene-butadiene copolymer, and 1.08 g / ml methyl methacrylate-styrene copolymer, wherein the size of the polymer particles ranges from 3 mm to 5 mm in diameter, and wherein the cleaning particles clean the entire inner surface of the walls of the tubular reactor and also the entire inner surface of the walls of the reservoir for storing algae for cultivation.

5. The system according to claim 3, wherein, In the cleaning particles coated with cationic silica nanoparticles (CNP), the diameter of the nanoparticles ranges from 50 to 200 nm, and the cleaning particles coated with cationic silica nanoparticles (CNP) have a cationic acrylate polymer with a length range of 1.8 nm to 2.3 nm.

6. The system according to claim 1, wherein, The automated algae cultivation system further includes one or more heat exchange devices to maintain the temperature of the automated algae cultivation system within a range of 15°C to 30°C, which is the temperature range for maintaining the optimal productivity of the algae.

7. The system according to claim 2, wherein, The tubular reactor is constructed of double-walled glass with a vacuum between it, and the vacuum between the double-walled glass of the tubular reactor acts as an insulation. The outer diameter and inner diameter of the outer tube in the double-walled glass are 0.08m and 0.076m, respectively; and the outer diameter and inner diameter of the inner tube in the double-walled glass are 0.05m and 0.046m, respectively. The outer and inner tubes are each 8m long. In the horizontal arrangement of the tubular reactor, each culture system has 10 loops, and in the vertical arrangement, each culture system has 7 loops to minimize total energy consumption. The outer tube and the inner tube are separated by 0.05 m due to a 180-degree bend after the next loop, and the circulation of algae culture in the tubular reactor is maintained at a maximum flow rate of 0.6 m / s.

8. The system according to claim 1, wherein, The automated algae cultivation system further includes: An algae culture reservoir, wherein the algae culture reservoir is constructed of a cylindrical tank and occupies 30% of the total volume of the algae culture system, and wherein the algae culture reservoir further includes one or more built-in sensors, including sensors for monitoring and measuring pH, turbidity, dissolved oxygen, chemicals, water level and flow rate; The control panel manages the flow rate of algae entering the tubular reactor and the flow rate of sterile water and other sterile liquids entering and exiting the tubular reactor. An air blower is located at the top of the culture system, and One or more pumps are used to control the flow rate of algae entering the tubular reactor and to manage the flow rate of sterile water and other sterile liquids entering and leaving the tubular reactor. A set of reflectors is provided to direct sunlight to the tubular reactor to enhance photosynthesis. The set of reflectors includes at least two translucent reflectors positioned at a 45° angle to the ground on the east and west sides of the tubular reactor, and at least one regular reflector positioned on the ground directly below the tubular reactor. The reflective surfaces of the translucent and regular reflectors face inwards towards the tubular reactor. The combination of the translucent and regular reflectors concentrates more sunlight around the tubular reactor and reflects it evenly onto the walls of the reactor and the algae within the reactor, resulting in uniform light intensity and increased photosynthetic efficiency. The plurality of computer-controlled solar panels for collecting solar energy include at least two solar panels mounted on the east and west sides, and at least one solar panel mounted on the ground directly below the tubular reactor. The array of solar panels is controlled by a computer-controlled motor to move them off the ground at an angle of up to 90° relative to the ground, and the array of solar panels faces inward toward the tubular reactor. The culture system also includes other devices, including a chemical feeder, a water feeder, and a recirculating culture medium feeder.

9. The system according to claim 8, wherein, The air blower pumps outside air into the algae culture reservoir, which is then injected through multiple holes in the front cover of the air blower. The air then passes through the glass fiber filter and the mangosteen filter of the air blower before entering the culture system. The mangosteen filter is used to better filter bacteria and algae strains.

10. The system according to claim 8, wherein, The at least one solar panel installed on the ground directly below the tubular reactor is fixed.

11. An automated algae cultivation system, comprising: Algae cultivation reservoir, used to supply algae to tubular reactors; At least one optically transparent tubular reactor for photosynthesis is connected to the algae culture reservoir for algae culture, wherein the walls of the tubular reactor are transparent to avoid blocking sunlight and are coated with a superhydrophobic coating to prevent biofilm formation. Cleaning particles coated with cationic silica nanoparticles (CNP) to scrape off unwanted particles, including biofilms, wherein the cleaning particles are carried within the tubular reactor along with a flow of water or liquid entering the tubular reactor to scrape off the biofilm. Multiple LED lights are installed around the tubular reactor to provide LED light for the nighttime algae cultivation; Multiple computer-controlled solar panels are installed around the tubular reactor to collect solar energy during the day and provide electricity at night to power the multiple LED lights; A set of reflectors is installed around the tubular reactor to direct sunlight to the tubular reactor to enhance photosynthesis; as well as A dehydration device, connected to the tubular reactor, is used to harvest cultured algae from the tubular reactor and to separate biomass from the cultured algae; and The automated algae cultivation system operates in a closed system, from initial cultivation in the tubular reactor to harvesting using the dehydration device, to prevent cross-contamination and ecosystem diversification. Due to the cleaning particles coated with CNP, the automated algae cultivation system is a self-cleaning system, and The automated algae cultivation system operates continuously for 24 hours, using sunlight during the day and LED light at night to cultivate algae.

12. The system according to claim 11, wherein, The walls of the tubular reactor are made of bismuth silicate glass or PMMA or a combination of both, due to their high transparency, high light transmittance of up to 98.5%, salt resistance, pH fluctuation resistance, weather resistance, corrosion resistance, chemical resistance and non-crackability, and the superhydrophobic coating is at least a polydimethylsiloxane (PDMS) / poly(methyl methacrylate) PMMA solution.

13. The system according to claim 12, wherein, The system comprises multiple tubular reactors arranged horizontally next to each other, or stacked vertically on top of each other, or arranged in combination.

14. The system according to claim 11, wherein, The cleaning particles may have different or the same density.

15. The system according to claim 14, wherein, The cleaning particles comprise at least three types of polymer particles, including 0.94 g / ml linear low-density polyethylene (LLDPE), 1.01 g / ml styrene-butadiene copolymer, and 1.08 g / ml methyl methacrylate-styrene copolymer, wherein the size of the polymer particles ranges from 3 mm to 5 mm in diameter, and wherein the cleaning particles clean the entire inner surface of the walls of the tubular reactor and also the entire inner surface of the walls of the reservoir for storing algae for cultivation.

16. The system according to claim 14, wherein, In the cleaning particles coated with cationic silica nanoparticles (CNP), the diameter of the nanoparticles ranges from 50 to 200 nm, and the cleaning particles coated with cationic silica nanoparticles (CNP) have a cationic acrylate polymer with a length range of 1.8 nm to 2.3 nm.

17. The system according to claim 12, wherein, The tubular reactor is constructed of double-walled glass with a vacuum between them, and the vacuum between the double-walled glass of the tubular reactor acts as an insulation.

18. The system according to claim 11, wherein, The automated algae cultivation system further includes: The algae culture reservoir, wherein the algae culture reservoir is constructed of a cylindrical tank and occupies 30% of the total volume of the algae culture system, and wherein the algae culture reservoir further includes one or more built-in sensors, including sensors for monitoring and measuring pH, turbidity, dissolved oxygen, chemicals, water level and flow rate; The control panel manages the flow rate of algae entering the tubular reactor and the flow rate of sterile water and other sterile liquids entering and exiting the tubular reactor. An air blower is located at the top of the culture system; One or more pumps are used to control the flow rate of algae entering the tubular reactor and to manage the flow rate of sterile water and other sterile liquids entering and leaving the tubular reactor. The set of reflectors is used to direct sunlight to the tubular reactor to improve photosynthesis. The set of reflectors includes at least two translucent reflectors located at an angle of 45° to the ground on the east and west sides of the tubular reactor, and at least one regular reflector located on the ground directly below the tubular reactor. The reflective surfaces of the translucent reflectors and the regular reflector face inward toward the tubular reactor. The combination of the translucent reflectors and the regular reflector concentrates more sunlight around the tubular reactor and reflects it evenly onto the walls of the tubular reactor and the algae inside the tubular reactor, resulting in uniform light intensity and increased photosynthetic efficiency. The plurality of computer-controlled solar panels are used to collect solar energy. The solar panels include at least two solar panels installed on the east and west sides, and at least one solar panel installed on the ground directly below the tubular reactor. The array of solar panels is controlled by a computer-controlled motor to move them off the ground at an angle of up to 90° relative to the ground, and the array of solar panels faces inward toward the tubular reactor. One or more heat exchange devices are provided to maintain the temperature of the automated algae cultivation system within a range of 15°C to 30°C, which is the temperature range for maintaining the optimal productivity of the algae. The culture system also includes other devices, including a chemical feeder, a water feeder, and a recirculating culture medium feeder.

19. The system according to claim 18, wherein, The air blower pumps outside air into the algae culture reservoir, which is then injected through multiple holes in the front cover of the air blower. The air then passes through the glass fiber filter and the mangosteen filter of the air blower before entering the culture system. The mangosteen filter is used to better filter bacteria and algae strains.

20. The system according to claim 18, wherein, The at least one solar panel installed on the ground directly below the tubular reactor is fixed.

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