HK1170374A - Cultivation, harvesting and processing of floating aquatic species with high growth rates - Google Patents

Description

Cultivation, harvesting and processing of high growth rate planktonic aquatic species

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No. 61/171,036 (entitled "cultivation, harvesting and processing of high growth rate planktonic aquatic species") filed 4/20/2009, which is incorporated herein by reference.

Technical Field

The present invention relates generally to growing and processing small aquatic photosynthetic organisms, such as algae, aquatic species, including small aquatic phytoplankton species (e.g., duckweed).

Background

The Lemnaceae (Lemnaceae) is a family of flowering plants, also known as the lemna family since this family includes lemna or lentils. Duckweed includes the genera Spirodela (Spirodela), Spirodela (Landoltia), Lemna (Lemna), Wolffia (Wolffia) and Wolffia (Wolfiella). Duckweed is a fast growing, high protein yield, high pigment monocot plant and is classified as a macrophyte. There are over forty species of duckweed worldwide, but duckweed is found to be most abundant in the temperate climatic environments of tropical regions. When subjected to temperatures below about twenty degrees celsius, the lemna plants form a non-floating structure called a scale-rooted loaf (turion) that sinks to the bottom of the tank and remains dormant until the environment is warm.

Duckweed is an important food source for waterfowls and is consumed by humans in some regions of southeast asia. Additionally, duckweed also provides protection for many aquatic species such as frogs, fish, and the like, while helping to bioremediate the natural environment of the aquatic species by absorbing excess mineral nutrients, particularly nitrogen and phosphorus. Duckweed grows on dirt or animal waste, which is typically free of toxic contaminants, and can be fed to fish or livestock, or spread as fertilizer in farmlands. However, duckweed to be used for human or animal consumption comprises a clean water retention period to ensure that the biomass is free of water-borne pathogens. Duckweed (duckweed) is used interchangeably with lemna (lemna) in the present application.

Disclosure of Invention

Some embodiments include a method of cultivating planktonic aquatic species, the method comprising: providing water from a source, said water being substantially free of toxic heavy metals; providing light; incubating at least one aquatic species in an isolated region containing said water; and harvesting the aquatic species. The aquatic species may be duckweed. The harvesting step may be completed when the aquatic species density is at an optimal harvest density. The water may be fresh water, brackish water or salt water. In a brackish or brackish water embodiment, the planktonic aquatic species may be a salt tolerant species. Harvested aquatic crops can be processed to extract protein and/or biomass that can be used for fermentation to alcohol, pyrolysis to high value fuels or combustion to obtain energy.

A preferred embodiment of the present invention provides an apparatus for growing aquatic species, the apparatus comprising: a container configured to hold sufficient aquatic species in the cultivation substrate for normal growth thereof, wherein the container has a structure that allows the cultivation substrate to flow in a continuous loop; said advancing means being configured to apply sufficient force to the growth substrate to move it; the automated harvesting system is configured to harvest the aquatic species without stopping movement of the aquatic species.

Another embodiment of the present invention provides an apparatus for growing aquatic species, the apparatus comprising: a container configured to hold sufficient aquatic species in a growth substrate to allow normal growth of the aquatic species, wherein the container is divided into growth compartments by a partition; the wind barrier devices are mounted on at least some of the partitions and configured to reduce forces exerted by wind on the aquatic species; the automated harvesting system is configured to harvest the aquatic species.

In an additional aspect of any embodiment, the container is configured such that ambient light impinges on the aquatic species.

In an additional aspect of any embodiment, the container is open at its top.

In additional aspects of any embodiment, the aquatic species is selected from the genera: spirodela (Spirodela), Spirodela (Landolia), Lemna (Lemna), Wolffia (Wolffia) and Wolffia (Wolfiella).

In another aspect, the aquatic species is duckweed.

In an additional aspect of any embodiment, the container is configured such that the depth of the incubation matrix is about 10cm to about 50 cm.

In an additional aspect of any embodiment, the container comprises a plastic lined tank.

In additional aspects of the foregoing embodiments, the container includes peripheral walls, and the apparatus further includes wind barrier means mounted on at least some of the peripheral walls and configured to reduce forces exerted by wind on the aquatic species.

In another aspect, the wind barrier device comprises a mesh curtain having a height of about 50cm to 100 cm.

In another aspect, the mesh curtain has a height of 70cm to 80 cm.

In another aspect, the curtain comprises a woven plastic.

In another aspect, the propulsion device is selected from a paddle wheel and a jet pump.

In another aspect, the propulsion device is a paddle wheel and the apparatus further comprises a control device configured to control the rotational speed of the propulsion device to be about 0rpm to about 2 rpm.

In another aspect, the aquatic species moves at a velocity of 0.01m/s to 0.10 m/s.

In another aspect, the harvesting system includes a conveyor belt configured to be movable into the growth substrate, thereby carrying a portion of the aquatic species out of the container.

In another aspect, the harvesting system includes a surface skimmer device.

In another aspect, the harvesting system includes means for recycling the growth substrate to the container.

In another aspect, the apparatus further comprises a sensor configured to monitor a physical value within the incubation matrix and to indicate to perform a task when the physical value is outside a preset parameter range.

In another aspect, the apparatus further comprises a nutrient tank in fluid communication with the container, wherein the physical value is a nutrient level within the culture medium and the operation is to distribute nutrients into the culture medium.

In another aspect, the nutrient is selected from the group consisting of nitrogen, phosphorus, potassium, carbon dioxide, and micronutrients.

On the other hand, the physical value is a pH value, and the work is performed by adding an alkaline salt to the culture medium.

In another aspect, the apparatus further comprises a spray system configured to apply a spray of aqueous solution across the width of the container.

In another aspect, the apparatus further includes a sensor configured to monitor a thickness of the float mat of the aquatic species and indicate a need to use the harvesting system when the float mat reaches a preset thickness.

A preferred embodiment of the present invention provides a method of growing an aquatic species, the method comprising: providing the apparatus of claim 1 or 2; placing a growth substrate within the container; introducing an aquatic species into said culture medium; and harvesting the aquatic species.

In another aspect, the apparatus further comprises a sensor configured to monitor a thickness of a float mat of the aquatic species and provide a signal when the float mat reaches a preset thickness; and, harvesting the aquatic species includes using the harvesting system in response to the signal.

In another aspect, the aquatic species is selected from the genera: spirodela, duckweed, wolffia, and wolffia.

In another aspect, the aquatic species is duckweed.

In another aspect, the cultivation substrate is selected from the group consisting of fresh water, brackish water and salt water.

Detailed Description

Aquatic species such as duckweed, wolffia, mosquito fern (mosquito fern), Japanese pagodatree, water lettuce, and the like can be processed to produce fuels and high value chemicals and materials due to their high cellulose and hemicellulose content. Processing of aquatic species can be accomplished by a number of methods or combinations of methods depending on the desired end product and/or intermediate product.

In a particular embodiment, the present invention provides a serpentine trough growth system (or single trough) comprising a plastic lined shallow pool with dividing walls or tortuous channels. As shown in fig. 1, the serpentine trough growth system is provided with a propulsion system that includes a propeller wheel that propels water and floating microcrop (microcrop) together to the on-site harvest site. The serpentine shaped trough is designed or configured for circulating the culture substrate (also referred to as liquid for simplicity) and for varying the liquid flow rate in a controlled manner to maintain uniform distribution of the duckweed throughout the production area. As the microcrop grows, it may form a floating mat on the water surface, which may become thicker. The float pad thickness can be closely monitored by an aerial photo imager and sensors located in critical areas within the tank. Systems and methods for performing such imaging are disclosed in U.S. provisional application No. 61/186,349, entitled "navigation instruments for measuring multilayered micro Density sensing and Growth", filed on 11.6.2009, which is incorporated by reference herein in its entirety. In particular embodiments, the critical areas include production areas that represent the growth of a microcrop in a growing system. In such embodiments, for example, floating pads of the microcrop tend to pile up or greatly thicken areas or areas where the microcrop is very small due to local structure of the growing system would not be selected as critical areas for sensor placement or for aerial imaging. The automated harvesting system may receive feedback from these sensors to adjust the frequency and quantity of duckweed harvested. The automated process can help maintain the yield of duckweed under conditions of optimal growth rate.

In some embodiments, the serpentine groove growth system is a modular design comprising four connected serpentine grooves or four single grooves. In a particular embodiment, the single slot has a footprint of about 2.50 hectares (hereinafter ha), about 10ha per module. In this embodiment, a single slot is about 518m long with four channels, each about 12m wide, and each channel has a usable volume of about 7,620m³The water depth is about 30 cm. The peripheral wall and the central partition wall (or "dike") are formed of compressed earth transported in civil work. In a specific example of this embodiment, a 30mil (i.e., about 0.76 mm thick) plastic High Density Polyethylene (HDPE) liner covers the flat bottom and sloped sidewalls to prevent the liquid growth substrate from contacting the soil components, to avoid the effects of wave action, and to extend the life of the bank. The lining also helps to avoid loss of water through seepage and to avoid contamination of groundwater. As used herein, "about" means a variation of ± 20% of the described value. It is to be understood that the specific dimensions described herein are for illustrative purposes and are not intended to limit the scope of the present application. By way of example only, a single slot may be at least about 0.5ha, or at least about 1ha, or at least about 1.5ha, or at least about 2ha, or at least about 2.5ha, or at least about 3ha, or at least about 3.5ha, or at least about 4ha, or at least about 4.5ha, or at least about 5ha, or at least about 5.5ha, or at least about6ha, or at least about 6.5ha, or at least about 7ha, or at least about 7.5ha, or at least about 8ha, or at least about 8.5ha, or at least about 9ha, or at least about 9.5ha, or at least about 10 ha. A single slot may be less than about 50ha, or less than about 40ha, or less than about 30ha, or less than about 25ha, or less than about 20ha, or less than about 15ha, or less than about 10ha, or less than about 8ha, or less than about 6ha, or less than about 5ha, or less than about 4ha, or less than about 3ha, or less than about 2ha, or less than about 1 ha. A single slot may be at least 10 meters long, or at least 20 meters long, or at least 50 meters long, or at least 100 meters long, or at least 150 meters long, or at least 200 meters long, or at least 250 meters long, or at least 300 meters long, or at least 350 meters long, or at least 400 meters long, or at least 450 meters long, or at least 500 meters long, or at least 550 meters long, or at least 600 meters long, or at least 650 meters long, or at least 700 meters long, or at least 750 meters long, or at least 800 meters long. A single slot may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more than 10 channels. Each passage may be from about 0.5 meters to about 50 meters, or from about 1 meter to about 40 meters, or from about 2 meters to about 30 meters, or from about 3 meters to about 30 meters, or from about 4 meters to about 25 meters, or from about 5 meters to about 20 meters, or from about 6 meters to about 18 meters, or from about 7 meters to about 15 meters, or from about 8 meters to about 15 meters, or from about 9 meters to about 12 meters. The monotrough water depth may be from about 1cm to about 100cm, or from about 2 cm to about 80cm, or from about 5cm to about 70cm, or from about 8 cm to about 60 cm, or from about 10cm to about 50cm, or from about 15 cm to about 40 cm, or from about 20 cm to about 30 cm. The monotrough water depth may be less than about 200 centimeters, or less than about 180 centimeters, or less than about 150 centimeters, or less than about 120 centimeters, or less than about 100 centimeters, or less than about 90 centimeters, or less than about 80 centimeters, or less than about 70 centimeters, or less than about 60 centimeters, or less than about 50 centimeters, or less than about 40 centimeters, or less than about 30 centimeters. An assembly may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 single slots.

Groundwater, surface water and reclaimed water are acceptable for duckweed growth as long as the biological and chemical growth standards are met. A series of treatment tanks with floating oxygen enhancers and in-line uv light can help to condition the water in the growth tank for recycling. A water quality sensor on the drain pipe can control the treatment process and monitor the water quality.

Paddle wheel

The serpentine trough includes a propelling means for moving the aqueous growth substrate with the growing microcrop. In a particular embodiment, the device comprises a paddle wheel comprising three metal wheels, each wheel being about 3.8m long by about 1.82m in diameter. Each wheel had eight galvanized blades, each blade was about 3.8m by about 41cm long and each blade was connected to a central shaft of about 15.24cm by a series of metal angles. There is a clearance of about 2.54cm at the blade edges and bottom to promote water circulation. An approximately 1HP (horsepower) motor connected to a 500: 1 gearbox powers the paddle wheel and controls speed through a Variable Frequency Drive (VFD) connected to a Programmable Logic Controller (PLC). The paddle wheel has a speed of about 0rpm to about 2rpm, thereby causing the duckweed to move at a speed of 0m/s to 0.3m/s, more preferably 0.01m/s to 0.10m/s, above the water surface. Speed is a function of operating conditions, such as harvest and nutrient addition, and weather parameters such as wind and sun exposure. The paddle wheel is controlled through a Human Machine Interface (HMI) connected to the PLC. In certain embodiments, the HMI includes a series of displays that integrate data received from the PLC and display the status of the system operation. The water velocity in all serpentine troughs was a default daily operating velocity of about 0.05 m/s.

Jet pump

In an alternative embodiment, the propulsion device comprises a jet pump, which is located underwater along the width of the channel. In a particular embodiment, a high pressure centrifugal pump of about 4HP pumps upstream water into a common manifold comprising about 20, about 9.5mm discharge pipes placed evenly. To control the water rate, a butterfly valve is connected to the PLC and is controlled by a pump displacement pressure transducer that regulates water flow and ejector pressure.

Wind-proof curtain

In certain embodiments, the woven plastic mesh may serve as a wind-resistant curtain to prevent duckweed from being squeezed by high winds. The plastic mesh may have openings of about 50% porosity to reduce wind turbulence and allow light to pass through. The height of the wind-resistant curtain is about 76cm and the curtain is mounted on top of the peripheral wall and the central partition wall. The curtains were connected to three cables of about 12.5ga, supported by galvanized T-bars placed every 6 meters.

Wind screens are also mounted on the floating structure to reduce wind parallel to the trough channels. Here, a solid curtain of the same plastic liner (30mil HDPE) can be attached to a frame of rectangular PVC pipe mounted on top of four PVC buoys. The curtain is about 76cm by about 12m and an air slit is provided at the bottom of the curtain about 5cm from the water surface. A slot of about 5cm may allow a portion of the air to flow at the bottom of the curtain and may help reduce downstream wind eddies. This pulls the mounting distance between the curtains apart. The floating curtain may be connected to two underwater cables of equal length to the raceway.

Nutrient system

A special fertilizer mixture containing the appropriate amounts and ratios of nitrogen, phosphorus, potassium and micronutrients may be stored in a high concentration in a nutrient tank. Sensors located in each module can monitor nutrient levels and control the dosing of nutrients through the HMI. Each nutrient station may have a concentrated nutrient tank connected to a dosing pump. When the nutrient level is below the preset point of the HMI, the dosing pump at the critical site is activated and adds concentrated nutrient to each serpentine groove in each module, thereby maintaining a uniform level throughout the serpentine groove. Nutrients can be added through the underwater line or spray system based on the amount of dosing and the growing season.

Another parameter that can be closely monitored and controlled in the growth reactor is pH and/or carbon dioxide concentration. As with the nutrient system, each module may have at least one pH sensor and/or at least one carbon dioxide sensor. A pH sensor and/or a carbon dioxide sensor may be used in series to indicate that adjustment is required by the addition of liquid or gas phase carbon dioxide and a basic salt such as sodium bicarbonate. The supply of carbon dioxide can be a commercially available carbon dioxide pure gas, mixture and readily available waste gas.

Spraying system

Sprinklers can be installed on the channels to cool the duckweed, thereby avoiding excessive heat in hot weather. When the air temperature is higher, the water sprayer can be opened to spray uniform water mist in the direction crossing the width direction of the channel. As the duckweed is constantly moving in the channel, the entire duckweed mat surface is subjected to the water mist. The spray system may also be used to compensate for moisture loss during evaporation, growth and harvesting. As mentioned above, a nutrient system may alternatively be connected to the spray line, thereby providing uniform addition of nutrients to the duckweed mat surface. The spraying system can be controlled by an electronic solenoid valve connected to the PLC; in a particular embodiment, these valves are about 2.5cm in diameter.

Grafting bud

In particular embodiments, once a tank with available water depth and nutrients is established, fresh, environmentally adapted wet duckweed may be introduced from an inoculation pond located near the production tank. 600g/m²The scion bud density of (a) was used to estimate the mass of duckweed manually placed on each trough. When duckweed begins to grow in the trough, a portion of the duckweed is manually transferred to a nearby trough and the process is repeated until all troughs are fully budded.

Multifunctional supply pipeline

In embodiments, primary supply lines for water, nutrients, and electricity are located between the modules to facilitate installation and distribution of each tank. Each assembly has a supply piping network connected to water, nutrients, and sensors that monitor tank operation. An electronic solenoid valve can control the addition of water and nutrients to the tank. In a particular embodiment, all solenoid valves are rated at 24 volts direct current (Vdc) and the minimum CV is 22CV to prevent high voltage loss. In this embodiment, the primary distribution tubes of the moisture and nutrient headers are about 250mm and about 110mm in diameter, respectively. The diameters of the supply branches for the water, nutrient and spray pipes were about 160mm, about 25mm and about 110mm, respectively.

Drainage and overflow

In a particular embodiment, each 2.5ha trough has two floor drains and two emergency spillways above the bank for excess water to escape. In this embodiment, each drain tank is about 1.5m by about 1.5m and is connected to a drain pipe of about 200 mm. The pneumatic drainage knife valve can control gravity self-flow towards the common ditch. The trench may be located at the end of the tank and may also be used for emergency overflows. Water from the ditch may drain by gravity into the earthen pond where it may be stored and treated for further reuse within the growth reactor.

Harvesting system (conveyor belt)

In one particular embodiment of the harvesting system, an aerial photo scanner and local sensors located on the serpentine trough monitor the thickness of the float mat and activate the harvesting process. Approximately 13m of harvesting channel wall extends from the end of the first section of the paddle wheel pushing the duckweed mat towards the conveyor belt. During harvesting, the water velocity was increased to 0.1m/s to reduce the harvest time. The conveyor belt at the end of the harvesting channel wall automatically lowers into the water below the duckweed mat. The duckweed mat flows through a harvesting channel of about 11m, in this region of the channel two robotic arms collect the duckweeds onto a conveyor belt. The remaining duckweeds flow through the other two portions of the paddle wheel, thereby causing the duckweeds to be redistributed evenly. The conveyor belt collects the planktonic duckweed mat and carries the duckweeds to a common auger that carries all of the duckweeds from two adjacent troughs to a collection vehicle. Excess moisture drained from the conveyor and auger is collected and drained back into the trough. An automated system and a series of algorithms on the PLC can synchronize the speed of the conveyor belt and the paddle wheel speed to control the harvest frequency and frequency. When harvest is collected, a weight sensor on the collection vehicle communicates with the harvesting system to stop harvesting and adjust the paddle wheel speed to normal operating mode. The crawler controller receives the vehicle full signal and prepares the dewatered duckweed biomass for transport to a processing building for bioconversion processing.

Harvesting system (skimming tool)

In another embodiment of the harvesting system, an aerial photo scanner and local sensors located on the trough monitor the thickness of the float mat and activate the harvesting process. A harvesting channel wall approximately 13m long extends from the end of the first section of the paddle wheel, which pushes the duckweed pad towards the skimmer. The duckweed mat flows across the width of the harvesting channel of about 11m, in this region of the channel two robotic arms bring the duckweeds down into a channel of about 2.75m width where the surface skimmer is placed along the width. During harvesting, the skimmer is placed as follows: the top 2.54cm of the floe was skimmed and the remaining water was allowed to flow under the skimmer and back into the normal flow of water in the tank. The harvest skimmer was about 2.75m wide by about 61cm deep and was made of aluminum plate, polyvinyl chloride (PVC) and insulating foam. Each skimmer had six funnels, about 46mm wide, that brought the duckweed to a PVC reducer union of about 127mm by about 76 mm. The skimmer is designed to optimize the percent solids harvested, thereby minimizing the mass of water that needs to be processed. This can be achieved by skimming the water twice, once with an aluminium plate in front of the skimmer and once with an aluminium plate at the edge of the PVC fitting protrusion. A grooved approximately 12mm PVC pipe was installed in front of the aluminum plate and engaged with the edge of the plate to prevent skimming from sucking in subsurface water. Six PVC fittings were then connected to a common drain through pipes having an inner diameter of about 110 mm. The automatic knife valve on the drain pipe is opened to start the skimming process. The common drain carries the duckweed and water mixture out of the tank by gravity into a common open channel connecting all of the tanks in the module. The mixture of duckweed and water in all of the troughs is collected and transported by a single conveyor. The conveyor belt pours the duckweeds into the cart, which is transported to a processing area. The water is then pumped back into the tank at the same rate as the water is skimmed from the tank. This is achieved by a level switch connected to the PLC. When harvesting is complete, the reflux pump is turned off and the knife valve is closed, the skimming step is stopped and the skimmer is filled with water. The skimmer is then pulled to the bottom of the tank to allow the lemna to flow out for normal planting operations. A common drain carries the duckweed and water mixture out of the tank by gravity to an open channel that connects to all of the tanks in the module. Subsequently, the water and floating duckweed within the open channel flow by gravity into the harvest pond. The harvesting tank is provided with a receiving part of duckweed and an overflow part of water. The conveyor belt located at the receiving portion collects the duckweeds and transports the duckweeds to the cart. A high capacity pump of about 50HP delivers water back into the tank. The pump is also used to push any remaining duckweed onto the conveyor belt. The skimmer, drain knife valve, conveyor belt and reflux pump are all connected to the PLC to control the harvesting operation. Weight sensors located within each cart communicate with the PLC to stop the harvesting process. When harvesting is complete, the reflux pump is turned off and the knife valve is closed to stop the skimming process and fill the skimmer with water. And then the skimmer is pulled to the bottom of the tank to enable the duckweeds to flow out for normal planting operation.

In certain embodiments, duckweed growth performance is maintained at an optimum state by a series of sensors that monitor pH, temperature, ammonia, and weather parameters. All monitoring information is fed back to a central human machine interface controlling the growth and harvesting process. The sophisticated computer model predicts any growth problems and alerts the operator to preventive treatment to minimize downtime.

The above-described serpentine groove system provides particular advantages. The serpentine system combines dynamic and static selection that causes water and duckweed to move very slowly to a single harvest point. The movement of water and duckweed can help maintain an even distribution of nutrients and temperature throughout the planktonic duckweed mat and water surface. This may help reduce nutrient boundaries of the duckweed roots with water. Another advantage of the low speed is to help maintain uniformity of the duckweed mat on the surface, especially redistribution in windy conditions. The paddle wheel system is an efficient and economical form of flowing large amounts of water in a closed circuit with low energy consumption. Due to the movement of the duckweeds, a single harvesting point can be installed at a significant location within the serpentine trough so that a small amount of power is used to collect the duckweeds (rather than water) and transport them to the collection point.

Static floating grid bioreactor

The floating grid system is a static design in which duckweeds are contained within floating compartments with curtains to avoid compaction of the duckweeds by the action of wind and waves. In a particular embodiment, each compartment is about 6m by about 6m, and each compartment is provided with a curtain that extends about 30cm above the water surface. A large capacity pump may be used to recirculate the liquid and add nutrients through the submerged tube banks throughout the bottom of the pond. In such embodiments, greater power is used to maintain a uniform distribution of nutrients and temperature. The harvesting process can be performed by installing a skimmer funnel in each compartment, approximately 44 skimmers per hectare. The skimmer funnel was suspended at the intersection of the four compartments so that the edge of the skimmer remained submerged for about 2.5cm regardless of the change in liquid level. During harvesting, the buoyant duckweed and water may be drawn at a rate of 160gpm for about 30 minutes by four skimmers and may be transported to a dewatering station where a vibrating screen separates the duckweed from the water. Another high capacity pump may then be used to pump water back into the production tank. Since about 160gpm contains only about 1% duckweed, a large amount of water and energy can be used during harvesting. The uniformity of the duckweed mat within all compartments may vary due to differences in the pumping rate caused by wind, duckweed mat thickness and redistribution.

As used herein, "biomass" is a population with abundant carbon content. Biomass may include or be derived from algae; aquatic species (e.g., lemna); certain plastics or other organic waste; conventional feedstocks for refinery cracking; farmland wastes or by-products (e.g., silage, manure, etc.); or a mixture of all or some of the above.

Embodiments of the invention include methods of growing planktonic aquatic species that can be used as fuels, foods, fertilizers, and/or bioremediation. Some embodiments provide methods of extracting proteins from wet biomass without a corresponding loss of carbohydrate.

In some embodiments, the planktonic aquatic species are grown as substantially single plants. In other embodiments, the phytoplankton species are grown in a mixture with other plants. In other embodiments, the planktonic aquatic species are grown as part of a complex ecosystem comprising one or more other animals, plants, or protists. In yet another embodiment, planktonic aquatic species are grown in an environment free of foreign organisms.

In some embodiments, the planktonic aquatic species grow directly exposed to sunlight. In other embodiments, planktonic aquatic species grow under indirect light. Other conditions may be selected and/or altered to support rapid growth, desirable protein distribution and/or carbohydrate production, and the like. These are the factors listed in table 1.

In some embodiments, the nitrogen source for promoting the growth of planktonic aquatic species is comprised of animal waste, such as cow dung or pig waste. In other embodiments, the source of nitrogen is urine. In other embodiments, the nitrogen source is biogas plant slurry. To regulate the plant growth temperature, the reactor may be equipped with heating elements and/or cooling systems. In some embodiments, the reactor is surrounded by a hood to prevent or reduce phytoplankton extrusion by wind. The fan housing can transmit light required by the growth of planktonic aquatic species.

In some embodiments, the reactor supporting the growth of planktonic aquatic species may be physically divided into separate sections to create separate growth compartments. In some embodiments, the material forming the reactor partition is metal, plastic, rubber, or a combination thereof. For example, the floating baffle network can interfere with the free flow of phytoplankton, thereby avoiding the extrusion/accumulation of wind, and the floating baffle network can maintain an even distribution of the plants throughout the surface of the cultivation substrate. The uniform density of the cultivated plants may increase the yield of the reactor, because the light received by the cultivation increases, more available nutrients are distributed on the cultivation and waste is removed from the cultivation. The uniform density of the cultivated plants can increase the measurement accuracy of the density of the cultivated material.

Harvested biomass, including aquatic species, can be processed into two components: a carbohydrate-rich solid phase and a protein-rich liquid phase (also called juice). The processing may be accomplished using a screw press, belt press, chopper, or the like, or combinations thereof. By way of example only, harvested biomass may be lysed in a chopper. As used herein, "lysing" biomass includes mechanical or chemical processes that disrupt the organism's tissue at the level of single cells or multicellular structures to make the carbohydrates, proteins, and micronutrients present within the biomass organism more readily applicable to downstream processing of purified proteins, carbohydrate-containing materials, or micronutrient-containing liquids. Lysis may include, for example, chopping, shredding, breaking, crushing, shredding, chemical treatment by osmotic pressure lysis or decomposition of biological structures. The lysed biomass may be pressed on a belt press to produce a juice and a first solid phase; the first solid phase can be pressed in a screw press to produce more juice and wet material, also known as "biomeal". The wet biocrude can comprise a carbohydrate-rich solid phase and can be further processed. The juices produced in the different pressing steps may be combined for further processing.

The wet biocrude can be processed based on various considerations (e.g., suitable for further use). By way of example only, the biomeal may be dried for use as a potent plant material. In other embodiments, the biocrude may be optimized for co-combustion with other hydrocarbon-based feedstocks (e.g., coal) through a pelletization process, or the like. In other embodiments, the biocrude is used as a feedstock for biofuel conversion. In other embodiments, the biocrude is further processed by physical or chemical means to further extract protein content.

Embodiments of the present invention are further illustrated by the following examples.

Examples

The following non-limiting examples are provided to further illustrate the embodiments of the present application. It should be appreciated by those of skill in the art that the techniques disclosed in the examples represent methods discovered by the inventors to function well in the practice of the application, and thus can be considered to constitute model examples for the practice of the application. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the application.

Example 1

FIG. 1 shows an exemplary system for growing aquatic species. The system comprises a container bounded by a bank 2, a wind-resistant curtain 3 being mounted on the bank 2. The vessel includes a water source that can provide water as a culture medium, a nutrient system ("nutrient and bicarbonate station" of fig. 1) that can provide at least one nutrient to the system, and a harvesting system 5 within a harvesting channel 4 in which the aquatic species are harvested. The harvested aquatic species may be transported to a processing center for further processing. The propulsion system 9 and the floating wind curtain 10 are placed inside the container. The system also includes sprinklers 1 (shown as solid dots) evenly distributed in a 4 by 4 matrix within the system, and a monitoring system 6 that monitors nutrient levels, pH, and temperature levels. The rotor blades 7 are placed in the arc-shaped part of the vessel. The system further comprises a drain and overflow system 8 (indicated by the two hollow dots on the right). The system may comprise a single-tank growth system of about 2.5 ha. The system can cultivate duckweed.

Example 2

FIG. 2 shows an exemplary static system for growing aquatic species. The system may include a support auger 11. In this exemplary system, there are thirty-four support augers. The harvesting branches are connected to supporting augers. In the particular configuration disclosed, there are eleven harvesting branches distributed in the system. The mixture of aquatic species and growth substrate may be harvested by the harvesting branch 14 and subsequently provided to the harvesting header 12 in a controlled manner. In this embodiment, the harvest header 12 comprises 6 inch PVC tubing. After separation of the culture substrate from the harvested aquatic species, the culture substrate may be transported back into the system through a recovery header 17, which again comprises 6 inch PVC tubing, and then back to the recovery branch 13. In this exemplary system, there are seven recovery branches. The system may comprise one or more drainage floor drains 15, 16, 18, 19 for recycling the cultivation substrate. The dimensions and number of particular portions of the system in the figures are for illustrative purposes of particular embodiments and are not intended to limit the scope of the present application. It is known to those skilled in the art that the size or number of specific portions of the system may be modified.

Example 3

In an alternative embodiment of the trough system, the individual troughs have an oval or circular configuration. Fig. 3 illustrates a configuration in which three such troughs are placed side-by-side. Other embodiments are also contemplated in which a single elliptical slot is used, or two mirror image slots are used. As can be seen, the trough system includes windbreaks on the walls or banks that make up the trough, as well as floating windbreaks.

The specific components of the trough system of the present embodiment, labeled with letters a-E in fig. 3, are depicted in more detail in fig. 4-8. Fig. 4 depicts a paddle wheel and support platform. The support platform has a concave top surface that matches the arc of the paddle wheel blades to more efficiently generate propulsion. Fig. 5 depicts a drainage floor drain, similar to that depicted in fig. 2. Figure 6 shows the floating wind curtain in more detail. FIG. 7 shows details of a floating harvest skimmer, which in this embodiment contacts duckweed or other aquatic species through an indentation in the wall forming the trough. Fig. 8 shows a conveyor-based harvesting system.

FIG. 9 is a top view of an exemplary wind resistant curtain structure. Exemplary configurations include 2 "SCH PVC pipe 21; 4 "SCH PVC tubing 22; 23; galvanized support wires 24; and eye bolt attachment 25; 23 indicates that the wind-shield curtain structure can float in the cultivation substrate (e.g. water); eye bolt attachment 25 shows the eye bolt where the support wire 24 is secured to the top of the PVC pipe 22. The support wire 24 may comprise a solid core of.041 ". The support wires 24 may support side loads on the wind-resistant curtain caused by, for example, wind. The eye bolt attachment 25 may not include a floating oil seal.

FIG. 10 is a perspective view of the exemplary wind curtain construction shown in FIG. 9. The vertical pipe connected to the PVC pipe (21 of FIG. 9) is a 1 "SCH 40PVC pipe. The wind-resistant curtain arrangement may further comprise a curtain attached to at least one of the PVC pipes comprising 21 of FIG. 9, 22 of FIG. 9 or a curtain attached to the vertical 1 "SCH 40PVC pipe, for example, the curtain may be bolted to the vertical 1" SCH40PVC pipe. The curtain may overhang an existing wall, such as a wall of a container. The curtain may be substantially rectangular.

The various methods and techniques described above provide many ways to implement the present application. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that the methods of achieving or optimizing one advantage or group of advantages taught herein may be practiced in part without necessarily achieving other objects or advantages as may be taught or suggested herein. The present application relates to many alternatives. It will be understood that some preferred embodiments specifically include one feature, another feature, or several features, while other embodiments specifically exclude one feature, another feature, or several features, while still other embodiments reduce a particular feature by including one feature, another feature, or several advantageous features.

In addition, those skilled in the art will recognize the applicability of various features in different embodiments. Similarly, the various elements, features and steps described above, as well as other known equivalents for each such element, feature or step, may be employed in various combinations by those of ordinary skill in the art to practice the methods of the invention, in accordance with the principles described herein. Various elements, features and steps will be specifically included in different embodiments, while other elements, features and steps will be specifically excluded.

Although the present application has been disclosed in the context of embodiments and examples, it will be understood by those skilled in the art that the embodiments of the present application extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and modifications and equivalents thereof.

In some embodiments, it will be understood that the numbers expressing properties, amounts of ingredients (e.g., molecular weights, reaction conditions, and so forth) used to describe and protect some embodiments of the present application are to be modified in certain instances by the term "about" or "substantially". For example, unless otherwise specified, "about" or "substantially" may indicate a variation of about ± 20% of the value described. Thus, in some embodiments, the numerical parameters set forth in the written description and attached claims are estimates that may vary depending on the desired properties to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be interpreted in accordance with the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the broad numerical ranges and parameters setting forth some embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible.

In some embodiments, the use of the singular terms ("a" and "an" and "the") and similar terms in describing certain embodiments of the present application are to be construed to cover both the singular and the plural. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided with respect to certain specific embodiments of the application, is intended merely to better illuminate the application and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.

Preferred embodiments of this application are described herein, including the best mode known to the inventors for carrying out the application. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. Those skilled in the art will recognize that such suitable variations may be used, and that the present application may be practiced otherwise than as specifically described herein. Accordingly, many embodiments of the present application include all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by the relevant law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the scope of the application unless otherwise indicated herein or otherwise clearly contradicted by context.

The entire contents of each patent, patent application publication and other material (e.g., articles, books, specifications, publications, documents, articles, and/or the like) referenced herein is incorporated by reference herein for all purposes, except to the extent that it is inconsistent or contrary to the context of this application or any application history data set forth herein as limiting the broadest scope of the present claims or that of any subsequent claims. For example, any incorporated material and the present document may have inconsistencies or contradictions in the relevant descriptions, definitions and/or uses of terms, subject to the descriptions, definitions and/or uses of terms in the present document.

Finally, it should be understood that the embodiments disclosed herein are implemented to illustrate the principles of the embodiments of the present application. Other modifications that may be employed may be within the scope of the present application. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present application may be used in accordance with the teachings of the present application. Accordingly, embodiments of the present application are not limited to those as precisely represented and described.

Claims (29)

1. An apparatus for cultivating aquatic species, the apparatus comprising:

a container configured to contain sufficient aquatic species in the cultivation substrate to allow normal growth of the aquatic species, wherein the container has a structure such that the cultivation substrate flows in a continuous loop;

a propulsion device configured to apply sufficient force to the growth substrate to move it; and

an automated harvesting system configured to harvest aquatic species without stopping movement of the aquatic species.

2. An apparatus for cultivating aquatic species, the apparatus comprising:

a container configured to hold sufficient aquatic species in a cultivation matrix to allow normal growth of the aquatic species, wherein the container is divided into growth compartments by a partition;

a wind barrier device mounted on at least some of the partitions and configured to reduce forces exerted by wind on the aquatic species, an

An automated harvesting system configured to harvest the aquatic species.

3. The apparatus of claim 1 or 2, wherein the container is configured such that ambient light impinges on the aquatic species.

4. The apparatus of claim 1 or 2, wherein the container is open at its top.

5. The apparatus of claim 1 or 2, wherein the aquatic species is selected from the genera: spirodela, duckweed, wolffia, and wolffia.

6. The apparatus of claim 5, wherein the aquatic species is duckweed.

7. The device of claim 1 or 2, wherein the container is configured such that the depth of the incubation matrix is about 10cm to about 50 cm.

8. The apparatus of claim 1 or 2, the vessel comprising a plastic lined tank.

9. The apparatus of claim 1, wherein the container comprises peripheral walls, and the container further comprises wind barrier means mounted on at least some of the peripheral walls and configured to reduce forces exerted by wind on the aquatic species.

10. The apparatus of any one of claims 2 to 9, wherein the wind barrier means comprises a mesh curtain having a height of about 50cm to 100 cm.

11. The apparatus of claim 10, wherein the mesh curtain has a height of 70cm to 80 cm.

12. The apparatus of claim 10, wherein said curtain comprises a woven plastic.

13. The apparatus of claim 1, wherein the propulsion device is selected from a paddle wheel and a jet pump.

14. The apparatus of claim 13, wherein the propulsion device is a paddle wheel, and the propulsion device further comprises a control device configured to control a rotational speed of the propulsion device from about 0rpm to about 2 rpm.

15. The apparatus of claim 13, wherein the aquatic species moves at a speed of 0.01m/s to 0.10 m/s.

16. The apparatus of claim 1, wherein the harvesting system comprises a conveyor belt configured to be movable into the culture substrate, thereby transporting a portion of the aquatic species out of the container.

17. The apparatus of claim 1 or 2, wherein the harvesting system comprises a surface skimmer.

18. The apparatus of claim 1 or 2, said harvesting system comprising means for recycling said incubation matrix to said container.

19. The apparatus of claim 1 or 2, further comprising:

a sensor configured to monitor a physical value within the incubation matrix and indicate a need to perform a job when the physical value is outside a preset parameter range.

20. The apparatus of claim 19, further comprising a nutrient tank in fluid communication with the container, wherein the physical value is a nutrient level within the growth substrate and the action is dispensing nutrients into the growth substrate.

21. The apparatus of claim 20, wherein the nutrient is selected from the group consisting of nitrogen, phosphorus, potassium, carbon dioxide, and micronutrients.

22. The apparatus of claim 19, wherein the physical value is a pH value and the action is adding an alkaline salt to the incubation matrix.

23. The apparatus of claim 1 or 2, further comprising a spray system configured to apply a spray of aqueous solution across the width of the container.

24. The apparatus of claim 1 or 2, further comprising a sensor configured to monitor a thickness of a floating mat of an aquatic species and indicate a need to use the harvesting system when the floating mat reaches a preset thickness.

25. A method of cultivating an aquatic species, the method comprising:

there is provided the apparatus of claim 1 or 2,

placing a growth substrate in the container,

introducing said aquatic species into said cultivation matrix, and

harvesting the aquatic species.

26. The method of claim 25, wherein the apparatus further comprises a sensor configured to monitor a thickness of a float mat of the aquatic species and provide a signal when the float mat reaches a preset thickness; and the number of the first and second electrodes,

harvesting the aquatic species includes using the harvesting system in response to the signal.

27. The method of claim 25, wherein the aquatic species is selected from the genera: spirodela, duckweed, wolffia, and wolffia.

28. The method of claim 27, wherein the aquatic species is duckweed.

29. The method of claim 25, wherein the incubation matrix is selected from the group consisting of: fresh water, brackish water and salt water.