Description:TECHNICAL FIELD
[0001] The present disclosure relates to systems for carbondioxide sequestration. In particular, the present disclosure relates to carbondioxide sequestration from industrial off-gases using photobioreactors.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed present disclosure, or that any publication specifically or implicitly referenced is prior art.
[0003] Many solutions have been proposed for addressing climate change, specifically addressing challenges in sequestration of carbondioxide from the atmosphere. Primary methods include planting of more trees to compensate for greenhouse gases, mainly carbondioxide, released to the atmosphere by human activity. Particularly, industrial off-gases have been particularly responsible for emission of significant amounts of greenhouse gases. However, planting trees is not sufficient to address the burgeoning problem of climate change. Trees take in the order of years to grow before they meaningful sequester carbondioxide, specifically carbondioxide, from the atmosphere. Further, the space requirements of trees make them unsuitable for large-scale implementation in urban environments.
[0004] As an alternative, an interest has been shown in cultivation of other photosynthetic microorganisms, such as microalgae and cyanobacteria for their higher photosynthetic efficiency and ability to grow at much faster rates compared to terrestrial plants. Some solutions have been proposed that cultivate the photosynthetic microorganisms that sequester carbondioxide efficiently. Such solutions also include self-contained systems that cultivate the photosynthetic microorganisms. However, such solutions have been found to have limited success, particularly for sequestering carbondioxide from industrial off-gases that often have higher temperatures, unwanted gases and contaminants that are toxic to photosynthetic microorganisms. Industries also produce significant amounts of volumes industrial off-gases, which existing solutions are not/cannot be adapted to.
[0005] Industrial off-gas often have temperatures that are too high for the photosynthetic microorganism. For instance, the off-gases emitted by industrial units, such as manufacturing plants or power generation plants, are between 80 ºC to 250 ºC or even more. Such temperatures are inviable for cultivating the photosynthetic microorganism, and achieving carbondioxide sequestration. As a reason, the temperatures of off-gases need to be reduced before they are fed to photosynthetic organisms. Industrial off gases also have Sulphur oxides (SOX), Nitrogen oxides (NOX), and other hydrocarbon compounds which are toxic to photosynthetic microorganisms. Such gases have to be reduced to a required/acceptable concentration before carbondioxide can be sequestered from the off-gases.
[0006] Further, when operating in industrial scales, it is desirable to provide treated water supply as a medium for cultivating photosynthetic microorganisms. Raw untreated water generally have unwanted microorganisms that compete for resources and nutrients with the photosynthetic microorganisms. Some microorganisms may also be predatory to the photosynthetic microorganism. Such unwanted microorganisms have to be removed from water for efficient carbondioxide sequestration. Further, water is also required to be treated for toxic components, suspended particles, and the like, to allow the photosynthetic microorganisms to sequester carbondioxide efficiently.
[0007] Additionally, industrial off-gases are emitted in significant volumes which a single photobioreactor unit cannot efficiently sequester carbondioxide from. Existing solutions are not adapted to operate at industrial volumes efficiently. While multiple photobioreactor units can be used in proportion to the volume of industrial off-gases, such solutions drastically increase cost of setting up and maintenance.
[0008] There is, therefore, a need for methods and systems for sequestering carbondioxide from industrial off-gases. Particularly, there is a need for methods and systems that handle industrial volumes of off-gases, reduce temperature, reduce toxic gaseous components, and purify water for allowing the photosynthetic microorganisms to sequester carbondioxide.
OBJECTS OF THE PRESENT DISCLOSURE
[0009] A general object of the present disclosure is to sequester carbondioxide from industrial off-gases using photobioreactors.
[0010] Another object of the present disclosure is to reduce temperature of off-gases for consumption by photosynthetic microorganisms.
[0011] Another object of the present disclosure is to scrub undesirable compounds from the off-gases for healthy cultivation of photosynthetic microorganisms.
[0012] Another object of the present disclosure is to remove unwanted microorganisms from water used for cultivating photosynthetic microorganisms.
[0013] Another object of the present disclosure is to remove toxic components, suspended particles, and the like, from water to create an environment where photosynthetic microorganisms can efficiently sequester carbondioxide from the industrial off-gases.
[0014] Another object of the present disclosure is to sequester carbondioxide from significant volumes of off-gases emitted by industrial units.
[0015] The other objects and advantages of the present disclosure will be apparent from the following description when read in conjunction with the accompanying drawings, which are incorporated for illustration of the preferred embodiments of the present disclosure and are not intended to limit the scope thereof.

SUMMARY
[0016] Aspect of the present disclosure relate to systems for a carbondioxide sequestration. In particular, the present disclosure relates to carbondioxide sequestration from industrial off-gases using photobioreactors.
[0017] In an aspect, a system for cultivating photosynthetic microorganisms for carbondioxide sequestration from industrial off gases includes a heat exchanger configured to reduce the temperature of industrial off-gases supplied thereto, a water purification unit configured to filter water to remove contaminants and microorganisms therefrom, a distribution tank configured to receive inoculum of photosynthetic microorganisms from an inoculum tank, and mix the inoculum with the water from the water purification unit, the off-gases from the heat exchanger, and nutrients from a nutrient storage tank to form a mixture to initiate growth of the photosynthetic microorganisms, and a photobioreactor that receives the mixture from the distribution tank and facilitates cultivation of the photosynthetic microorganisms for sequestering carbondioxide.
[0018] In some embodiments, the heat exchanger may be configured to absorb heat and reduce the temperature of the industrial off gases to less than about 40 ºC.
[0019] In some embodiments, the heat exchanger receives water from a cooling tower as a coolant for reducing the temperature of the off-gases therein.
[0020] In some embodiments, the water purification unit may include a water filter that filters the water for contaminants, and a sterilizer that sterilizes the water using ultraviolet radiation.
[0021] In some embodiments, the water has pH of about 7, and 0.1 Nephelometric Turbidity Units (NTUs).
[0022] In some embodiments, the system may include a scrubber unit that chemically scrubs unwanted gases from the off-gases, wherein the scrubber unit supplies the scrubbed off-gases to the heat exchanger unit.
[0023] In some embodiments, the system may include a direct heat transfer unit configured to further reduce temperature of the off-gases.
[0024] In some embodiments, the distribution tank may include, media distribution unit, a lighting unit that provides light for cultivation of the photosynthetic microorganisms, and a sparger that aerates the water with the off-gases including CO2 or a bottom off-gases distribution unit within tank.
[0025] In some embodiments, the distribution tank may distribute the mixed photosynthetic microorganisms to the photobioreactor at predetermined quantities at predetermined intervals.
[0026] In some embodiments, the photobioreactor may include one or more biofilm panels having a surface, wherein the photosynthetic microorganisms adhere to and grow on the surface when the mixture may be supplied to the one or more biofilm panels by a pump, a lighting unit that emits light towards the one or more biofilm panels. The photosynthetic microorganisms consume the mixture and the light to sequester carbondioxide therefrom.
[0027] In an aspect, a method for cultivating photosynthetic microorganisms for carbondioxide sequestration from industrial off gases includes reducing heat of the industrial off-gases to less than about 40 C, filtering and sterilizing water to remove contaminants and unwanted microorganisms therefrom, and aerating the water with carbondioxide from the off-gases. The method includes mixing inoculum of photosynthetic microorganisms and nutrients to form a mixture to initiate growth of the photosynthetic microorganisms, and periodically supplying the mixture through a photobioreactor to cultivate the photosynthetic microorganisms for sequestering carbon.
[0028] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0029] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0030] FIG. 1 illustrates an exemplary representation of a system for sequestering carbondioxide from industrial off-gases, in accordance with an embodiment of the present disclosure.
[0031] FIG. 2 illustrates a flowchart of a method for sequestering carbondioxide from industrial off-gases, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0032] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0033] As used herein, “substantially” means largely or considerably, but not necessarily wholly, or sufficiently to work for the intended purpose. The term “substantially” thus allows for minor, insignificant variations from an absolute or perfect state, dimension, measurement, result, or the like as would be expected by a person of ordinary skill in the art, but that do not appreciably affect overall performance.
[0034] As used herein, “about” means approximately or nearly, and in the context of a numerical value or range set forth means ±10% of the numeric value.
[0035] Embodiments explained herein relate generally to systems for carbondioxide sequestration. In particular, the present disclosure relates to carbondioxide sequestration from industrial off-gases using photobioreactors.
[0036] In an aspect, a system for cultivating photosynthetic microorganisms for carbondioxide sequestration from industrial off-gases includes a heat exchanger that reduces the temperature of industrial off-gases supplied thereto, a water purification unit that filters and sterilizes water to remove contaminants and microorganisms therefrom, a distribution tank that receives inoculum of photosynthetic microorganisms from an inoculum tank, and mixes the inoculum with the water from the water purification unit, the off-gases from the heat exchanger, and nutrients from a nutrient storage tank to form a mixture to initiate growth of the photosynthetic microorganisms, and a photobioreactor that receives the mixture from the distribution tank and facilitates cultivation of the photosynthetic microorganisms for sequestering carbondioxide therefrom.
[0037] FIG. 1 illustrates an example representation of the system 100, in accordance with an embodiment of the present disclosure. As shown, the system 100 includes a heat exchanger 102, a water purification unit 104, a scrubber unit 105, a cooling tower 107, and a direct heat transfer unit 108, which pre-process industrial off gases and water. Further, the system 100 includes a distribution tank 110 connected to an inoculum tank 112 and a nutrient storage tank 114, that mixes the off gasses, the water, inoculum of photosynthetic microorganisms, and nutrients therefor to form a mixture. The system 100 further includes a photobioreactor 116 that sequesters carbondioxide from the mixture.
[0038] In some embodiments, the system 100 may include the heat exchanger 102 that reduces the temperature of industrial off-gases supplied thereto. In some embodiments, industrial off-gasses may correspond to effluent gases from industrial machinery, such as gases emitted by including, but not limited to, refineries, cement plants, power plants, chemical manufacturing plants, sugar plants, paper mills, steel plants, container vehicles such as ships, and the like. In some embodiments, the off-gases may include, but not be limited to, carbondioxide, carbon monoxide, sulphur oxides, nitrogen oxides, and other greenhouse gases and pollutants. At least some of the aforementioned off-gases may be detrimental to the growth and health of the photosynthetic microorganisms in the photobioreactor 116. Reducing the temperature of the off-gases may be necessary because high temperatures can harm microorganisms or inhibit their growth. In some embodiments, the industrial off gases may have high concentration of CO2 (about 3-15% V/V). Further, industrial off-gases typically have temperatures of about 80 to 250 C.
[0039] In some embodiments, the off gases may be supplied to the system 100 by a conveying means such as including, but not limited to, pipes, conduits, channels passages, and the like. In such embodiments, the conveying means may include one or more induced draft fans or blowers that draw the off gases thereinto and transport the off gases therethrough to the system 100. In some embodiments, the heat exchanger 102 may receive the off gases from the industries through the conveying means.
[0040] In some embodiments, the heat exchanger 102 may be configured to reduce the temperature of the off gases. In some embodiments, the heat exchanger 102 may be configured to absorb heat and reduce the temperature of the industrial off gases to less than about 40 C. In preferred embodiments, the off gases may be reduced to temperatures less than about 35C. In such embodiments, the temperature of the off gases may be reduced such that said off gases facilitate growth of the photosynthetic microorganism.
[0041] In some embodiments, the heat exchanger 102 may be indicative of any cooling system that absorbs heat from the off gases, and dissipates heat therefrom. In some embodiments, the heat exchanger 102 may be any one of including, but not limited to, a conventional air-fin cooler, a shell-and-tube heat exchanger, a plate heat exchanger, or any other type of heat exchanger suitable for the specific application. In some embodiments, the heat exchanger 102 may allow for transfer of thermal energy from the off-gases to the ambient environment or to a coolant, such as water. On removing thermal energy from the off-gases, its temperature may be reduced.
[0042] In some embodiments, the heat exchanger 102 may be connected to the cooling tower 107. The heat exchanger 102 may use water in the cooling tower 107 as a coolant for reducing the temperature of the off-gases therein. The water from the cooling tower 107 may allow cool the components of the heat exchanger 102. Further, the water from the cooling tower 107 may absorb heat from the off gases. In some embodiments, the heat exchanger 012 may recirculate the water back to the cooling tower 107, wherefrom heat may be dissipated to the ambient environment. In some embodiments, the cooling tower 107 may be supplied with water from the water purification unit 104.
[0043] In other embodiments, the system 100 may also include the scrubber unit 105 that chemically scrubs unwanted gases from the off-gases. The unwanted gases may include, but not be limited to, sulphur oxides, nitrogen oxides, hydrocarbon compounds, and the like, which may be damaging to the photosynthetic microorganisms. In some embodiments, the scrubber unit 105 may scrub unwanted gases from the off gases by techniques, including, but not limited to, wet scrubbing, dry scrubbing, absorbers, and the like. In such embodiments, the scrubber unit 105 supplies the scrubbed off-gases to the heat exchanger unit 104. In a preferred embodiment, sulphur oxides and nitrogen oxides may be removed using wet scrubbing.
[0044] In some embodiments, the water purification unit 104 may filter and sterilize water to remove contaminants and microorganisms therefrom. In some embodiments, the water may be supplied to the water purification unit 104 from a water source. In some embodiments, the water source may include, but not be limited to, ponds, lakes, rivers, reservoirs, tanks, water storage structures, underground water, and the like. In some embodiments, the water may be supplied from the water source to the water purification unit 104 using a water conveyance means, such as a water pump and piping system.
[0045] In some embodiments, the water purification unit 104 may include a water filter configured to filter contaminants from water. In some embodiments, the water filter may filter the water using any one or combination of including, but not limited to, clarifier, sedimentary filtration, active carbondioxide filtration, ultrafiltration, microfiltration, osmosis, reverse osmosis, and the like. In some embodiments, the contaminants may include, but not be limited to, dirt, dust, sediments, particulate matter, and the like. In other embodiments, the water filter may include a sterilizer that sterilizes the water using ultraviolet (UV) radiation. The UV radiation may neutralize or inactivate bacteria and/or viruses in the water, thereby preventing other organisms from consuming or competing with the photosynthetic microorganisms for resources.
[0046] In some embodiments, the water may be purified by the water purification unit 104. The water may be purified such that the pH of the water is about 7, and the turbidity of the water is about 1 Nephelometric Turbidity Units (NTUs).
[0047] In some embodiments, the system 100 may include a direct heat transfer unit 108 to further reduce temperature of off gases, using cooling water directly. In some embodiments, the direct heat transfer unit 108 may further facilitate the heat exchanger 102 to reduce temperature of the off-gases.
[0048] In some embodiments, the distribution tank 110 may be configured to initialize cultivation of the photosynthetic microorganisms. In some embodiments, the distribution tank 110 may receive inoculum of the photosynthetic microorganisms from the inoculum tank 112. In some embodiments, the photosynthetic microorganisms may be a consortium of any one or more of including, but not limited to, microalgae, cyanobacteria, macroalgae, and the like. The photosynthetic microorganisms may be any public known species of microorganisms that perform photosynthesis, and may be procured from sources known to those skilled in art. In some embodiments, the inoculum tank 112 may store and periodically supply the inoculum of the photosynthetic microorganisms therein. In some embodiments, the inoculum of the photosynthetic microorganisms may be indicative of cell cultures and/or seeds of the photosynthetic microorganism.
[0049] In some embodiments, the nutrient storage tank 114 may be configured to store and periodically supply nutrients to the distribution tank 110. In some embodiments, nutrients may include, but not be limited to, micro-nutrients and macro-nutrients that promote growth of the photosynthetic microorganisms. In some embodiments, the nutrients may include, but not be limited to, nitrogen, phosphorous, potassium, and other growth promoting compounds. The nutrients may be stored in either liquid or solid form. In some embodiments, the nutrients may be water soluble. The combination of nutrients used may be suitably adapted based on requirements (such as the type of microorganisms used).
[0050] In some embodiments, the distribution tank 110 may be configured to receive and mix the inoculum with the water from the water purification unit 104, the off-gases from the heat exchanger 102, and nutrients from the nutrient storage tank 114 to form a mixture to initiate growth of the photosynthetic microorganisms. In some embodiments, the distribution tank 110 may be equipped with mixing mechanisms, such as stirrers or impellers, to ensure that the seeds/inoculum of photosynthetic microorganisms, water, off-gases, and nutrients are thoroughly combined to create a mixture that is conducive to the growth and proliferation of the photosynthetic microorganisms. In some embodiments, the distribution tank 110 may mix the mixture until the mixture is substantially homogenous.
[0051] In some embodiments, the distribution tank 110 may include a media distribution unit. The media distribution unit may be configured to uniformly dispense the media into the distribution tank. The media distribution unit may include passive distributors (such as pored or slotted plates), or active distributors (such as level sensors that dispense the media into the distribution tank level of the media over the media distribution unit or within the distribution tank 110. In some embodiments, the media distribution unit may be placed above the distribution tank 110. In some embodiments, the distribution tank 110 may also include a lighting unit that provides light for cultivation of the photosynthetic microorganisms. In such embodiments, the distribution tank 110 may allow the inoculum to germinate. In some embodiments, the light provided by the lighting unit may be consumed by the inoculum for germination, and promoting growth of the photosynthetic microorganism. In some embodiments, the distribution tank 110 may include a sparger that aerates the water with the off-gases including CO2, or a bottom off-gases distribution unit within the distribution tank 110. The bottom off-gases distribution unit may include multiple spargers placed in a uniform fashion.
[0052] In some embodiments, the distribution tank 110 may distribute the mixed photosynthetic microorganisms of predetermined quantities to the photobioreactor 116 at predetermined intervals. In such embodiments, the distribution tank 110 may supply the mixture to the photobioreactor 116 in one or more batches, thereby allowing photobioreactors 116 to efficiently sequester from the off gases. Further, by supplying the mixture in batches, the system 100 may be enabled to operate in industrial settings where the volume of off gasses is significantly high. The predetermined quantities and the predetermined intervals may be suitably adapted based on volumes of off gases emitted by the industry.
[0053] In some embodiments, volume of the mixture circulated by the distribution tank 110 to the photobioreactor 116 may be predetermined based on the type of photosynthetic microorganism used, the stress profile of the photosynthetic microorganism, the type of biofilm panels, capacity of the photobioreactors 116, desired growth rate of the photosynthetic microorganism, volume of off gases emitted by the industry, speed of processing off-gases, and the like. In some embodiments, the cycle time of releasing the predetermined quantities may be controlled via, but not limited to, programmable logic controllers (PLCs), timers, automated feed systems, or manual controls. In some embodiments, the cycle time may be optimized to maximize the absorption of carbondioxide by the photosynthetic microorganisms in the photobioreactor 116, and to maintain optimal growth conditions within the photobioreactor 116.
[0054] In some embodiments, the system 100 include the photobioreactor 116 which may be configured to receive the mixture from the distribution tank 110 and facilitate cultivation of the photosynthetic microorganisms for sequestering carbondioxide therein. In some embodiments, the photobioreactor 116 may include one or more biofilm panels having a surface. The photosynthetic microorganisms may adhere to and grow on the surface when the mixture may be supplied to the one or more biofilm panels by a pump (not shown). In some embodiments, the photobioreactor 116 may be a photobioreactor 116 as disclosed in Indian Patent filing bearing Application Number 202311030438, which is incorporated herein by reference. In other embodiments, the photobioreactor 116 may be any off the shelf photobioreactor 116 adapted for sequestering carbon from industrial off gases processed by the system 100
[0055] In an embodiment, the pump may be configured to draw the mixture from the distribution tank 110, and circulate the mixture through the one or more biofilm panels. In some embodiments, the pump may be any one of including, but not limited to, centrifugal pump, submersible pump, and the like. In some embodiments, the pump may include a suction that sucks the mixture from the distribution tank 110, and one or more outlets with at least one of the said outlets coupled to a feed line connecting the pump to the one or more biofilm panels. In some embodiments, the feed line may be adapted to release the mixture circulated by the pump over the one or more biofilm panels at a predefined speed that allows the photosynthetic microorganism therein adheres to the surface the one or more biofilm panels.
[0056] Further, the photobioreactor 116 may include a lighting unit that emits light towards the one or more biofilm panels. In some embodiments, the spectral attributes of the light emitted by the lighting unit may be adjustable based on requirement.
[0057] In some embodiments, the one or more biofilm panels may be composed of including, but not limited to, polyethylene (PE), polypropylene (PP), polyester (PET), polyvinyl chloride (PVC), fiber-reinforced plastic (FRP), recycled plastic, recycled composite material, flat cloth sheeting, nylon sheeting, organic fabric, cotton duck or any combinations thereof. In some embodiments, the biofilm panels may be formed in any suitable shape, size, and texture that may be conducive for the photosynthetic microorganisms to adhere to the surface of said biofilm panels. In some embodiments, the biofilm panels may also be treated or coated with a material, such as a hydrophilic layer, bacterial layer, bio-coating, and the like, that facilitates adhesion and growth of the photosynthetic microorganisms. In some embodiments, the photosynthetic microorganisms growing on the surface of the biofilm panels may utilize the carbon, the nutrients, the water, and the light provided by the photobioreactor 116, for growth.
[0058] In some embodiments, the lighting unit may include one or more light emitters configured in a lattice arrangement or any other lighting modules within the photobioreactor 116. In some embodiments, the light emitters may be Light Emitting Diodes (LEDs) that emit photosynthetic active radiation required to promote growth and photosynthetic activity of photosynthetic microorganisms. In other embodiments, the at least one light emitter may be any one or combination of including, but not limited to, incandescent lamps, filament lamps, florescent lamps, plasma lamps, artificial sunlight, solar simulators, and the like. In some embodiments, the light emitters of the lighting unit may be configured to controllably emit light at a predefined set of spectral attributes of light for promoting growth of the photosynthetic microorganism. In some embodiments, the set of spectral attributes includes predefined ranges of intensity, irradiance, wavelength, and luminous exposure of light emitted by the lighting unit.
[0059] In some embodiments, the pump may distribute the mixture on the surface of each biofilm panels. In some embodiments, the pump controllably releases the mixture to allow the photosynthetic microorganisms therein to evenly adhere to the surface of the biofilm panels. The photosynthetic microorganisms may adhere to and accumulate over the surface of the biofilm panels.
[0060] In some embodiments, the photobioreactor 116 may include a scrapper movably configured to the biofilm panels. As the scrapper moves across the length of the corresponding biofilm panels, the scrapper may scrub off the photosynthetic microorganisms layer having size above a predetermined threshold that may be adhered to the biofilm panels. In some embodiments, the photosynthetic microorganism layer may be indicative of one or more layers of the photosynthetic microorganisms that adhere on top of the surface of the biofilm panels. In such embodiments, the predetermined threshold may be determined to maximized light penetration through the photosynthetic microorganisms growing on the surface of the corresponding biofilm panels, thereby the improving efficiency of carbondioxide sequestration.
[0061] FIG. 2 illustrates a flowchart of a method 200 for sequestering carbondioxide from industrial off-gases, in accordance with an embodiment of the present disclosure.
[0062] At step 202, the method 200 includes reducing heat of the industrial off-gases to less than about 40 C. In some embodiments, the heat of the industrial off gases may be reduced using a heat exchanger and/or a direct heat transfer unit, such as the heat exchanger 102 and the direct heat transfer unit 108 of FIG. 1.
[0063] At step 202, the method 200 includes filtering and sterilizing water to remove contaminants and unwanted microorganisms therefrom. In some embodiments, the water may be filtered and sterilized using a water purification unit, such as the water purification unit 104 of FIG. 1.
[0064] At step 206, the method 200 includes aerating the water with the off-gases. In some embodiments, the media may be aerated or contacted with the off gases by a distribution tank, such as the distribution tank 110 of FIG. 1,
[0065] At step 208, the method 200 includes mixing inoculum of photosynthetic microorganisms and nutrients therefor in the aerated water to form a mixture to initiate growth of the photosynthetic microorganisms. Step 208 may be performed using the distribution tank 110.
[0066] At step 210, the method 200 includes periodically supplying the mixture through a photobioreactor, such as the photobioreactor 116 of FIG. 1, to cultivate the photosynthetic microorganisms for sequestering carbon. In some embodiments, the mixture may be supplied using a pump.
[0067] In some embodiments, the system 100 and method 200 may be implemented in an industry or industrial machinery where off-gases with a high concentration of CO2 are emitted as a result of combustion processes. In such implementations, the industrial machinery (such as refineries, cement plants, power plants, chemical manufacturing plants, sugar plants, paper mills, steel plants, container vehicles such as ships, but not limited thereto) may often emit off-gases at significant temperatures with increased contaminants, and in substantial volumes. To sequester carbondioxide from such off-gases efficiently, the system 100 integrates the heat exchanger 102, the water purification unit 104, the scrubber unit 105, and the distribution tank 110 that work in conjunction to precondition/treat the off-gases and prepare the cultivation setup within the photobioreactor 116. The integration of the system 100 into such industrial applications may allow for reduction of greenhouse gas emissions, and effectively managing environmental impacts.
[0068] The system 100 sequester carbondioxide from the industrial off gases using the photobioreactor 116. The system 100 is designed to optimize the growth conditions for photosynthetic microorganisms, maximize carbondioxide sequestration, and streamline the process of harvesting the biomass resulting from the growth of these organisms. The system 100 pre-processes the off-gases to allow the photobioreactor 116 to be adjusted to accommodate for variations in off-gas flow rates, temperatures, and compositions, resilience against contaminants, ensuring efficient operation under fluctuating industrial conditions, and effective carbondioxide capture.
[0069] Therefore, the present disclosure solves the need for sequestering carbondioxide from industrial off-gases.
[0070] While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the present disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0071] The present disclosure provides a system and a method that sequesters carbondioxide from industrial off-gases using photobioreactors.
[0072] The present disclosure provides a system that reduces temperature of off-gases for consumption by photosynthetic microorganisms.
[0073] The present disclosure provides a system that scrubs undesirable compounds from the off-gases for healthy cultivation of photosynthetic microorganisms.
[0074] The present disclosure provides a system that removes unwanted contaminants and microorganisms from water used for cultivating photosynthetic microorganisms.
[0075] The present disclosure provides a system that removes toxic components, suspended particles, and the like, from water to create an environment where photosynthetic microorganisms can efficiently sequester carbondioxide from the industrial off-gases.
[0076] The present disclosure provides a system that sequesters carbondioxide from significant volumes of off-gases emitted by industrial units.
, Claims:1. A system (100) for cultivating photosynthetic microorganisms for carbondioxide sequestration from industrial off gases, the system (100) comprising:
a heat exchanger (102) configured to reduce the temperature of industrial off-gases supplied thereto;
a water purification unit (104) configured to filter water to remove contaminants and microorganisms therefrom;
a distribution tank (110) configured to receive inoculum of photosynthetic microorganisms from an inoculum tank (112), and mix the inoculum with the water from the water purification unit (104), the off-gases from the heat exchanger (102), and nutrients from a nutrient storage tank (114) to form a mixture to initiate growth of the photosynthetic microorganisms; and
a photobioreactor (116) configured to receive the mixture from the distribution tank (110) and facilitates cultivation of the photosynthetic microorganisms for sequestering carbondioxide therein.

2. The system (100) as claimed in claim 1, wherein the heat exchanger (102) is configured to absorb heat and reduce the temperature of the industrial off gases to less than about 40 C.

3. The system (100) as claimed in claim 1, wherein the heat exchanger (102) is configured to receive water from a cooling tower as a coolant for reducing the temperature of the off-gases therein.

4. The system (100) as claimed in claim 1, wherein the water purification unit (104) comprises:
a water filter that filters contaminants from the water; and
a sterilizer that sterilizes the water using ultraviolet radiation.

5. The system (100) as claimed in claim 1, wherein the water has pH of about 7, and 0.1 Nephelometric Turbidity Units (NTUs).

6. The system (100) as claimed in claim 1, comprising a scrubber unit (105) is configured to chemically scrub unwanted gases from the off-gases, wherein the scrubber unit (105) supplies the scrubbed off-gases to the heat exchanger unit (102).

7. The system (100) as claimed in claim 1, further comprising a direct heat transfer unit (108) is configured to further reduce temperature of the off-gases.

8. The system (100) as claimed in claim 1, wherein the distribution tank (110) comprises:
a lighting unit configured to provide light for cultivation of the photosynthetic microorganisms; and
a sparger that aerates the water with the off-gases or a bottom gas distribution unit.

9. The system (100) as claimed in claim 1, wherein the distribution tank (110) distributes the mixed photosynthetic microorganisms to the photobioreactor (116) at predetermined quantities at predetermined intervals.

10. The system (100) as claimed in claim 1, wherein the photobioreactor (116) comprises:
one or more biofilm panels having a surface, wherein the photosynthetic microorganisms adhere to and grow on the surface when the mixture is supplied to the one or more biofilm panels by a pump; and
a lighting unit that emits light towards the one or more biofilm panels, wherein the photosynthetic microorganisms consume the mixture and the light to sequester carbondioxide therefrom.

11. A method (200) for cultivating photosynthetic microorganisms for carbondioxide sequestration from industrial off gases, the method comprising:
reducing heat of the industrial off-gases to less than about 40 C;
filtering and sterilizing water to remove contaminants and unwanted microorganisms therefrom;
aerating the water with carbondioxide from the off-gases;
mixing inoculum of photosynthetic microorganisms and nutrients therefor in the aerated water to form a mixture to initiate growth of the photosynthetic microorganisms; and
periodically supplying the mixture through a photobioreactor (116) to cultivate the photosynthetic microorganisms for sequestering carbon.