Photobioreactor apparatus and method

Abstract

Photobioreactor devices and units for the production of biomass and remediation of environmental pollution are provided. The bioreactor devices include: (i) a photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers being arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer to form a defined boundary around the non-bonded portions of the first and second membrane layers, thereby defining the photobioreactor unit capable of containing a fluid, wherein at least one of the first and second layers is translucent, and wherein at least a portion of the first and second membrane layers is permeable to gas. The permeability coefficient of oxygen through the first and / or second membrane layers is suitably not less than about 100 Barrer, typically not less than about 300 Barrer, and suitably not less than about 500 Barrer. The photobioreactor unit further includes inlet and outlet ports for enabling circulation of the fluid through the unit. Systems including the devices and methods of using the devices to produce biomass, remediate wastewater, and remove atmospheric pollutants are provided.

Description

TECHNICAL FIELD

[0001] The present invention relates to a photobioreactor device which can be used to generate biomass and to assist in environmental remediation. Such a device can also remove gases such as carbon dioxide and nitrogen oxides from the environment and can generate oxygen. BACKGROUND

[0002] As the world moves away from reliance on fossil fuel-based energy, biomass is becoming increasingly important for energy generation, production of chemicals, and other industrial and environmental applications. Biomass derived from non-food sources is of particular interest because it can be produced more quickly than other types of land-based agricultural biomass, such as corn and soybeans, and once harvested, can be processed (e.g., by fermentation or purification) to produce biofuels such as biodiesel, ethanol, butanol, and methane (biogas) and / or to produce valuable chemicals and nutrients.

[0003] US2014 / 186909 describes a photobioreactor capsule made of a transparent (or translucent) flexible polymeric film divided into a plurality of adjacent channels in communication with a fluid distribution structure.

[0004] GB2339763 describes a photobioreactor made of a transparent material comprising a flexible bag having an inlet and an outlet and a plurality of linear seals defining a plurality of conduits. The flexible bag is made of a non-permeable plastic or polymer.

[0005] US2015 / 0230420 relates to a photobioreactor and a biogas unit equipped with such a photobioreactor, which uses a transparent piping system for the flow-through of the culture suspension, which is configured in the form of liquid levels in order to realize the culture over several liquid levels.

[0006] DE102012013587 relates to a photobioreactor comprising a disposable bag defining a reactor cavity delimited by a wall and a light source arranged in the immediate vicinity of the wall.

[0007] US2014 / 0093924 describes a flat biofilm photobioreactor system with photosynthetic microorganisms, self-fermenting microorganisms forming a biofilm and producing chemical products by photosynthesis and subsequent self-fermentation.

[0008] WO2015 / 116963 relates to a bioreactor defining a substantially closed system except for at least one opening allowing the introduction of gas and / or nutrients. The way in which the gas and / or nutrients are introduced is to provide mixing and aeration of the cell culture in the bioreactor.

[0009] US2009 / 305389 describes a photobioreactor comprising a flexible outer bag having a membrane tube inside the outer bag allowing introduction of high concentrations of carbon dioxide into the medium contained within.

[0010] US2011 / 312084 describes a photobioreactor comprising an acrylic polymer in the form of a thin film, a plate or a cylinder such as a pipe.

[0011] There is a need for new highly scalable and low cost bioreactors capable of producing large amounts of biomass to meet current energy and environmental challenges, in addition, there is a demand for photobioreactors that facilitate ease of installation, have relatively low running costs and can contribute to environmental remediation such as the uptake of greenhouse gases or the treatment of polluted water sources. As will become apparent in the following disclosure, the present invention seeks to address these or other problems. SUMMARY

[0012] A first aspect of the present invention provides a photobioreactor apparatus, the photobioreactor apparatus comprising:

[0013] (i) a photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers being arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer to form a defined boundary around non-bonded portions of the first and second membrane layers, thereby defining a photobioreactor unit capable of containing a fluid,

[0014] wherein at least one of the first and second layers is translucent, and

[0015] wherein at least a portion of the first and second membrane layers is permeable to gas, wherein the permeability coefficient of oxygen across the first and / or second membrane layer is suitably not less than about 100 Barrer, typically not less than about 300 Barrer, and suitably not less than about 400 Barrer; and

[0016] (ii) inlet and outlet ports for enabling circulation of the fluid through the unit.

[0017] According to embodiments of the present invention, substantially all of the first membrane layer is permeable to gas. In alternative embodiments, the second membrane layer is permeable to gas, optionally substantially all of the first and second membrane layers are permeable to gas.

[0018] In one embodiment of the application, the permeability coefficient of oxygen through the first membrane layer and / or the second membrane layer is suitably no less than about at least 500 Barrer, at least 650 Barrer, at least 750 Barrer, suitably at least 820 Barrer. Suitably, at least a portion of the first membrane layer and the second membrane layer is permeable to carbon dioxide, and the permeability coefficient of carbon dioxide permeability is selected from the group consisting of no less than at least 1000 Barrer, at least 2000 Barrer, at least 2200 Barrer, at least 2500 Barrer, at least 2800 Barrer, at least 2900 Barrer, at least 3000 Barrer, at least 3100 Barrer, at least 3200 Barrer, at least 3300 Barrer, at least 3400 Barrer, at least 3500 Barrer, at least 3600 Barrer, at least 3700 Barrer, at least 3800 Barrer, suitably at least 3820 Barrer. In particular embodiments of the application, at least a portion of the first membrane layer and / or the second membrane layer is permeable to other gases, including but not limited to nitric oxide and methane.

[0019] In embodiments of the application, at least one of the first membrane layer and / or the second membrane layer comprises a suitably translucent or even substantially transparent material selected from the group consisting of silicone, polysiloxane, polydimethylsiloxane (PDMS), fluorosilicone, and organosilicone. In particular embodiments, the material comprises polydimethylsiloxane (PDMS) or elastomers thereof.

[0020] In embodiments of the application, at least one photosynthetic microorganism is included within the unit. Suitably, the photosynthetic microorganism is selected from the group consisting of Haematococcus sp., Haematococcus pluvialis, Chlorela sp., Chlorela autotraphica, Chlorela vulgaris, Scenedesmus sp., Synechococcus sp., Synechococcus elongatus, Synechocystis sp., Arthrospira sp., Arthrospira platensis, Arthrospira maxima, Spirulina sp., Chlamydomonas sp., Chlamydomonas reinhardti, Geitlerinema sp., Lyngbya sp., Chroococcidiopsis sp., Calothrix sp., Cyanothece sp., Oscilatoria sp., Gloeothece sp., Microcoleus sp., Microcystis sp., Nostoc sp., and Anabaena sp. Optionally, the photosynthetic microorganism is selected from the group consisting of Dunaliela salina and Synechococcus marinus.

[0021] In one embodiment, the photobioreactor unit further comprises at least one flow control structure. Optionally, the photobioreactor unit further comprises at least one biological support.

[0022] In specific embodiments, the photobioreactor further comprises an auxiliary system in fluid communication with the photobioreactor unit. Typically, the auxiliary system comprises at least one or more of the group consisting of: conduits; reservoirs; pumps; valves; biomass separators; lighting systems; temperature control systems; sensors; and computer / CPU controllers.

[0023] In one embodiment, the apparatus comprises a plurality of photobioreactor units. Optionally, the plurality of photobioreactor units are in fluid communication with one another and arranged in an array. Suitably, the array of photobioreactor units can be configured in series or alternatively in parallel.

[0024] A second aspect of the application provides a photobioreactor system, the photobioreactor system comprising:

[0025] (a) at least one photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers being arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer to form a defined boundary around non-bonded portions of the first and second membrane layers, thereby defining a photobioreactor unit capable of containing a fluid,

[0026] wherein at least one of the first and second layers is translucent, and

[0027] wherein at least a portion of the first and second membrane layers is permeable to gas, wherein the permeability coefficient of oxygen across the first and / or second membrane layer is suitably not less than about 100 Barrer, typically not less than about 300 Barrer, and suitably not less than about 400 Barrer; and

[0028] an inlet and outlet port for enabling circulation of the fluid through the unit;

[0029] (b) a fluid reservoir in fluid communication with the inlet and outlet ports of the at least one photobioreactor unit;

[0030] (c) a pump for maintaining circulation of fluid throughout the system; and

[0031] (d) a biomass collector.

[0032] A third aspect of the application provides a method for producing biomass, the method comprising culturing photosynthetic microorganisms within an apparatus as set out above, and harvesting the biomass from the apparatus.

[0033] A fourth aspect of the application provides a method for producing biomass, the method comprising culturing photosynthetic microorganisms within a system as set out above, and harvesting the biomass from the system.

[0034] A fifth aspect of the application provides a method for treating wastewater, the method comprising culturing photosynthetic microorganisms within an apparatus as set out above, passing wastewater through the apparatus, whereby the photosynthetic microorganisms within the apparatus remove or remediate toxins from the wastewater.

[0035] A sixth aspect of the application provides a method for removing atmospheric pollutants, the method comprising: culturing photosynthetic microorganisms within a device as set out above, exposing the device to an atmosphere comprising the pollutants, thereby causing the photosynthetic microorganisms within the device to remove or remediate the pollutants from the atmosphere.

[0036] A seventh aspect of the application provides a photobioreactor device, the photobioreactor device comprising:

[0037] (i) a photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers being arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer to form a defined boundary around non-bonded portions of the first and second membrane layers, thereby defining a photobioreactor unit capable of containing a fluid,

[0038] wherein at least one of the first and second layers is translucent, and

[0039] wherein at least a portion of the first and second membrane layers comprises a polysiloxane; and

[0040] (ii) an inlet and outlet port for enabling circulation of the fluid through the unit.

[0041] In particular embodiments of the application, the polysiloxane comprises polydimethylsiloxane (PDMS) or an elastomer thereof.

[0042] In an eighth aspect, the application provides a photobioreactor device, the photobioreactor device comprising:

[0043] (i) a photobioreactor unit comprising a first membrane layer and a second membrane layer, the two membrane layers being arranged such that at least a portion of the first membrane layer is directly bonded to at least a portion of the second membrane layer to form a defined boundary around non-bonded portions of the first and second membrane layers, thereby defining a photobioreactor unit capable of containing a fluid,

[0044] wherein at least one of the first and second layers is translucent, and

[0045] wherein at least a portion of the first membrane layer and the second membrane layer is permeable to a gas, wherein the permeance coefficient of carbon dioxide across the first membrane layer and / or the second membrane layer is selected from the group consisting of: no less than at least 1000 Barrer, at least 2000 Barrer, at least 2200 Barrer, at least 2500 Barrer, at least 2800 Barrer, at least 2900 Barrer, at least 3000 Barrer, at least 3100 Barrer, at least 3200 Barrer, at least 3300 Barrer, at least 3400 Barrer, at least 3500 Barrer, at least 3600 Barrer, at least 3700 Barrer, at least 3800 Barrer, suitably at least 3820 Barrer; and

[0046] (ii) an inlet and an outlet port for enabling circulation of the fluid through the unit.

[0047] It will be appreciated that aspects and embodiments of the application can be subject to further combinations of features not explicitly stated above but described in detail herein. BRIEF DESCRIPTION OF DRAWINGS

[0048] The application is further illustrated with reference to the accompanying drawings, in which:

[0049] Figure 1 A cross-sectional view of a device according to an embodiment of the application is shown (cross-section A) with a first membrane layer and a second membrane layer represented by triple hatching. Figure 27a A cross-sectional view of a device according to an embodiment of the application is shown (cross-section A) with a first layer and a second layer both being membrane layers, and with an additional component located inside the unit formed by these two layers. Single hatching in the opposite direction indicates the additional component.

[0050] Figure 2 A cross-sectional view of a device according to an embodiment of the application is shown (cross-section A) with a first layer and a second layer both being membrane layers, and with an additional component located inside the unit formed by these two layers. Single hatching in the opposite direction indicates the additional component. Figure 27a

[0051] Figure 3 A cross-sectional view of a unit according to an embodiment of the application is shown with a first layer and a second layer both being membrane layers, and with a bio-support coating the inner surface of both layers. Grey fill colour represents the bio-support coating.

[0052] Figure 4 A cross-sectional view of a unit according to an embodiment of the application is shown with a first layer and a second layer both being membrane layers, and with a bio-support coating the inner surface of one of the membrane layers. Dashed fill / small crosses indicate a porous additional component.

[0053] Figure 5 ​A cross-sectional view of a unit with a first membrane layer and a second membrane layer is shown, according to an embodiment of the application, wherein an additional component is located inside the unit formed by these two membrane layers, and wherein the additional component is coated on one side / surface with a biological support.

[0054] Figure 6 A cross-sectional view of a unit with a first membrane layer and a second membrane layer is shown, according to an embodiment of the application, wherein an additional component is located inside the unit formed by these two membrane layers, and wherein the additional component is coated on one side / surface with a biological support.

[0055] Figure 7 A cross-sectional view of a unit with a first membrane layer and a second membrane layer is shown, according to an embodiment of the application, wherein the inner surface of each membrane layer is in contact with a porous additional component.

[0056] Figure 8 A cross-sectional view of a unit with a first membrane layer and a second membrane layer is shown, according to an embodiment of the application, wherein the inner surface of one membrane layer is in contact with a porous additional component.

[0057] Figure 9 A cross-sectional view of a unit with a first membrane layer and a second membrane layer is shown, according to an embodiment of the application, wherein a porous additional component is located inside the unit formed by these two membrane layers.

[0058] Figure 10 A simple front view streamlined version of a unit is shown, according to an embodiment of the application, the unit having one fluid conduit with an inlet and an outlet located on opposite sides.

[0059] Figure 11 A simple front view streamlined version of a device is shown, according to an embodiment of the application, the device having two fluid conduits with an inlet and an outlet located on opposite sides of the device and a single control structure.

[0060] Figure 12 A front view streamlined version of a device is shown, according to an embodiment of the application, the device having multiple fluid conduits. The central portion has both linear and streamlined flow control structures.

[0061] Figure 13 A front view streamlined version of a device is shown, according to an embodiment of the application, the device having multiple circular flow control structures creating multiple different paths.

[0062] Figure 14 An arrangement configured to increase the surface area of a device is shown. There are multiple portions that protrude radially outward, each including a flow control structure as described in Figure 12

[0063] ​Figure 15 A diagram of a device according to embodiments of the application is shown, where the inlet and outlet are positioned adjacent to each other on the same side of the device. There is a linear control flow structure that creates a single channel within the pocket.

[0064] Figure 16 A version of a device according to embodiments of the application is also shown, where the inlet and outlet are positioned adjacent to each other on the same side of the device. In this front view diagram of the device, the central portion has a linear and streamlined flow control structure that creates a bifurcated channel.

[0065] Figure 17 A linear device according to embodiments of the application is shown, having one fluid conduit with an inlet and an outlet located on opposite sides.

[0066] Figure 18 A linear device according to embodiments of the application is shown, having two fluid conduits with an inlet and an outlet located on opposite sides of the device and a single control structure in the central portion.

[0067] Figure 19 A device according to embodiments of the application is shown, comprising multiple circular flow control structures that create multiple different paths.

[0068] Figure 20 A version of a device according to embodiments of the application is shown, having four branches with multiple openings that serve as both an inlet and an outlet.

[0069] Figure 21 An arrangement of multiple protrusions that create multiple channels according to embodiments of the application is shown.

[0070] Figure 22 A linear U-shaped device according to embodiments of the application is shown, having a single channel created by a linear flow control structure. Both the inlet and outlet are located on the same side of the device.

[0071] Figure 23a A rectangular device according to embodiments of the application is shown, having a single fluid conduit along a curved path created by multiple control structures, with an inlet and an outlet located on opposite sides of the device.

[0072] Figure 23b A rectangular device according to embodiments of the application is shown, having a single fluid conduit along a curved, tortuous path created by multiple control structures. Both the inlet and outlet are located on the same side of the device.

[0073] Figure 24 is an example of a modular array of multiple devices including flowline and insertion devices according to embodiments of the present application.

[0074] Figure 25 is an example of a modular array of multiple devices including linear devices according to embodiments of the present application.

[0075] Figure 26 is an example of a modular array of multiple devices configured to occupy a rectangular space according to embodiments of the present application. Each individual device shown in this illustration is a device within the scope of the present application.

[0076] Figure 27a shows planar cross sections A and B through an illustration of a device according to embodiments of the present application and is included to aid in the understanding of other figures provided herein.

[0077] Figure 27b shows planar cross section C through an illustration of a device according to embodiments of the present application having one single film layer that is folded upon itself and thus glued to form a cell.

[0078] Figure 27c shows planar cross section D through an illustration of a device having a central control structure according to embodiments of the present application and is included to aid in the understanding of other figures provided herein.

[0079] Figure 28a shows a cross-sectional view of a cell having a first film layer and a second film layer glued together by a glue interface according to embodiments of the present application. Figure 27a cross section B of

[0080] Figure 28b shows a cross-sectional view of a cell having a first film layer and a second film layer with a structural component therebetween, where the films are glued to opposing surfaces of the structural component by a glue interface according to embodiments of the present application. Figure 27a cross section B of

[0081] Figure 29a shows a cross-sectional view of a cell having a first film layer and a second film layer glued together by a glue interface according to embodiments of the present application. A central glue forms a control structure creating two fluid conduits. Figure 27c cross section D of

[0082] Figure 29b shows a cross-sectional view of a cell having a first film layer and a second film layer with a structural component therebetween, where the films are glued to opposing surfaces of the structural component by a glue interface according to embodiments of the present application. Figure 27cCross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique.

[0083] Figure 30 Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique. Figure 27c

[0084] Figure 31 Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique. Figure 27c

[0085] Figure 32a Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique. Figure 27b

[0086] Figure 32b Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique. Figure 32a Figure 27b

[0087] Figure 33a

[0088] Figure 33b Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique. Figure 33a

[0089] Figure 34 Cross section D) of the device according to an embodiment of the application showing the mixed composition representing the bonding technique.

[0090] Figure 35 Schematic representation of an auxiliary system controlling the generation and harvesting of biomass of a single device according to an embodiment of the application.

[0091] Figure 36 Representation of the cycle of generation and harvesting of biomass using a device according to an embodiment of the application (on a continuous or batch basis).

[0092] ​​​​​​​Figure 37 is a graphical illustration of the cycle of generating and harvesting biomass using the device according to embodiments of the application (on a continuous or batch basis).

[0093] Figure 38 is a cross-sectional view of a device according to embodiments of the application (cross-section B) in which the unit is composed of a single tubular shaped membrane layer extrusion. Figure 27a

[0094] Figure 39 is a cross-sectional view of a device according to embodiments of the application (cross-section A) having a membrane layer and a non-membrane layer. Figure 27a

[0095] Figure 40 is a schematic illustration of a system described in the examples according to embodiments of the application.

[0096] Figure 41a is a graphical illustration of the results of an example of oxygen concentration in the liquid medium for a first experimental run (Run A).

[0097] Figure 41b is a graphical illustration of the results of an example of oxygen concentration in the liquid medium for a second experimental run (Run B). DETAILED DESCRIPTION

[0098] All references cited herein are incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0099] The inventors of the present application have developed a gas permeable photobioreactor device suitable for generating biomass. Advantageously, biomass can be continuously generated within the device and can be continuously harvested. The amount of generated biomass can be increased or optimized, for example, by combining multiple units in a modular fashion or by optimizing the shape and / or thickness of the device and its components or by utilizing different microorganisms. Furthermore, embodiments of the present application can also be used to facilitate the controlled transfer of gases such as oxygen and / or carbon dioxide between the external atmosphere and the liquid medium within the unit for growing microorganisms.

[0100] Embodiments of the present application are optimized to maximize the photosynthetic efficiency of the photosynthetic microorganisms contained within the unit and, therefore, the efficiency of biomass generation.

[0101] Before the present application is further described, it is to be understood that some definitions will aid in the understanding of the application.

[0102] ​​As used herein, the term "comprising" means including, necessarily including but not limited to, any recited elements and optionally also including other elements. "Consisting essentially of means including any recited elements and optionally including other elements so long as such other elements do not materially alter the basic and novel characteristics of the listed elements. "Consisting of means including only those elements listed. Embodiments defined by each of these terms are within the scope of the application.

[0103] As will be known to the skilled person, the term "photosynthesis" refers to the biochemical process that occurs in green plants and other photosynthetic organisms, including photosynthetic microorganisms including algae and cyanobacteria. The photosynthesis process uses light to convert carbon dioxide and water into metabolites and oxygen. As used herein, the term "photosynthetic microorganism" refers to any microorganism that is capable of photosynthesis. As used herein, the related terms "photoautotrophic" and "photoenergetic" are synonymous with "photosynthetic" and the two terms can be used interchangeably herein.

[0104] As used herein, the term "translucent" has its ordinary meaning in the art and refers to a light-transmitting material that allows light to pass through, causing any internal scattering of the light. The term is synonymous with "semi-transparent".

[0105] As used herein, the term "transparent" has its ordinary meaning in the art and refers to a material that allows visible light to pass through, such that objects can be clearly seen on the other side of the material, in other words, it can be described as "optically clear". All films and non-film materials, additional components, control structures, coatings and other materials described herein can be substantially translucent or substantially transparent.

[0106] As used herein, the term "permeable" or "gas permeable" means allowing a gas, in particular oxygen (O2), carbon dioxide (CO2), nitrogen (N2) and optionally methane (CH4), to transfer from one side of the material to the other layer in either or both directions. As used herein, the related terms "breathable" and "semi-permeable" are synonymous with "permeable" and the two terms can be used interchangeably herein. Typically, the material is in the form of a sheet, a thin film or a membrane. Permeation is directly related to the concentration gradient of the permeant, such as a gas, the absolute permeability of the material and the diffusivity of the permeant species in the membrane material.

[0107] The permeability of a gas through a particular material is measured herein in Barrers. The Barrer measurement is a rate of gas flow through a region of material having a certain thickness driven by a given pressure. Barrers are typically calculated at 23°C (+- 2°C) and are defined as:

[0108]

[0109] It will be appreciated that the Barrer is the most common measurement of gas permeability in current use and is particularly relevant to gas permeable membranes, however permeability can also be defined by other units, examples of which include kmol.m.m -2 .s -1 ·kPa -1 、m 3 .m.m -2 .s -1 .kPa -1 or kg.m.m -2 .s -1 .kPa -1 .ISO 15105-1 specifies two methods for determining the gas transmission rate of a single- layer plastic film or sheet or a multi-layer structure at differential pressure. One method uses a pressure sensor, while the other method uses gas chromatography to measure the amount of gas that penetrates the test sample. Other equivalent measurements of gas permeability are known to the skilled person and will readily be equivalent to the Barrer measurement described herein.

[0110] As used herein, the terms "porous" and "non-porous" refer to the porosity of a material as a means of classifying the mechanism by which a permeant penetrates the material. If gas particles migrate by direct movement through a microporous structure, the membrane material is referred to as porous, and if the transport of the permeant species occurs by a more complex physical / chemical mechanism from one side of the membrane to the other, these membrane materials are referred to as non-porous.

[0111] As used herein, the term "biomass" refers to any living or dead microorganism, including any part of a microorganism (including metabolites and byproducts excreted by the microorganism). In the context of the present invention, the term "biomass" specifically includes the photosynthetic synthesis products as described above.

[0112] As used herein, the term "water absorption" has its usual meaning in the art and is a measure of the tendency of a material to absorb and transmit water and other liquids by capillary action. The related term "hygroscopicity" also refers to the ability of an object to absorb and retain water from its surroundings. These two terms can be used interchangeably herein.

[0113] As used herein, the term "biofilm" refers to a group of microorganisms in which cells are attached to each other on a surface.

[0114] As used herein, the term "pocket" also refers to "unit," and the two terms can be used interchangeably herein.

[0115] As used herein, a "device" can be comprised of one "unit" or "pocket," or can include an array or combination of multiple "units" or "pockets."

[0116] As used herein, the term "fluid" refers to a flowable material, typically a liquid and suitable liquid media included within the units and thus the devices of the present invention.

[0117] As used herein, the term "liquid medium" has its usual meaning in the art and is a liquid used for growing microorganisms and containing microorganisms. The liquid medium can include one or more of the following: fresh water, salt water, physiological saline, brine, seawater, wastewater, nutrients, phosphates, nitrates, vitamins, minerals, micronutrients, metals, microbial growth media, BG11 growth media, and microorganisms.

[0118] Similarly, the related terms "water channel," "fluid channel," "fluid conduit," "fluid medium conduit," and "liquid medium channel" are synonymous, and the terms can be used interchangeably herein.

[0119] As used herein, the related terms "photobioreactor" and "photo-bio- reactor" are synonymous, and the two terms can be used interchangeably herein.

[0120] Outer layer

[0121] According to one embodiment of the present application, there is provided a device comprising a unit comprising an outer layer that is a membrane layer. One membrane layer can be flexible, although both membrane layers are flexible according to typical embodiments. At least a portion of one of the membrane layers, and optionally both the first and second membrane layers, have a high permeability to transport gases across the membrane. The permeability coefficient of oxygen across the membrane is not less than about 100 Barrer, typically about 300 Barrer and suitably about 400 Barrer. In particular embodiments of the present application, the permeability coefficient of oxygen across the membrane is not less than about 500 Barrer and can be higher. The permeability coefficient of carbon dioxide across the membrane is not less than about 1000 Barrer, suitably about 2500 Barrer and typically about 3000 Barrer. In particular embodiments of the present application, the permeability coefficient of carbon dioxide across the membrane is not less than about 3200 Barrer. As used in this context, the phrase "at least a portion" means a region of the layer having a sufficient size to allow a gas to pass through the outer layer of the unit. The gas is typically oxygen and carbon dioxide, but is not limited thereto, and can include nitrogen, nitric oxide, sulfur oxide and / or methane.

[0122] The device can be illuminated from a single direction or from multiple directions. If the device is positioned such that it receives light primarily from a single direction, and one (the first) membrane layer is less transparent or less translucent than the other (the second) membrane layer, the first membrane layer can be on the side of the device facing the primary light source. In particular embodiments, the first membrane layer is on the side of the device facing away from the light source.

[0123] Typically, the membrane layers are at least translucent, and are suitably substantially transparent.

[0124] Typically, the membrane layers comprise one or more gas permeable materials. Importantly, the gas permeable material is not permeable to liquids, which serves to prevent leakage of the liquid medium inside the unit to the outside of the unit. The gas permeable material can be porous (including microporous structure gas permeable materials) or non-porous. The gas permeable material is referred to as porous if gas particles can migrate by direct movement through the pores of the microporous structure. If the gas permeable material is porous, it is important that it is substantially not permeable to liquids. Suitably, the gas permeable material is non-porous, which also serves to avoid permeation of liquids through the gas permeable material and to avoid lower transparency that can be associated with porosity of the material.

[0125] The gas permeable material can be a polymer, such as a chemically optimized gas permeable polymer. Chemically optimized polymers can be advantageous over corresponding unmodified polymers as they can be cheaper, more tear resistant, hydrophobic, antistatic, more transparent, easier to manufacture, non-fragile, more elastic, more gas permeable and selectively permeable to specific gases. Chemical modifications to the polymer can be made by any means known to those skilled in the art, such as by changing the chemical composition of the monomers, backbone chain, side chains, end groups and / or using different curing agents, cross-linking agents, fillers, vulcanization processes, manufacturing processes, fabrication processes and other methods.

[0126] The membrane layer can comprise any suitable gas permeable material, including but not limited to: silicone, polysiloxane, polydimethylsiloxane (PDMS), fluorosilicone, organosilicone, cellulose (including plant cellulose and bacterial cellulose), cellulose acetate (cellophane), nitrocellulose and cellulose esters.

[0127] In suitable embodiments, the membrane layer comprises a polysiloxane, optionally an optimized polysiloxane. The polysiloxane can be chemically modified or mechanically modified. Typically, the membrane layer comprises a polysiloxane elastomer. Polysiloxanes have been found to be good candidates for gas permeable membranes, also thanks to the Si-O bond into the polymer structure, which promotes higher bond rotation, thus increasing chain mobility and therefore increasing the level of permeability. Polysiloxane elastomers, such as silicone rubbers, are also flexible materials, UV radiation resistant materials and elastic materials.

[0128] In embodiments, the membrane layer comprises a polydimethylsiloxane (PDMS), suitably an optimized polydimethylsiloxane. Typically, the membrane layer comprises a polydimethylsiloxane (PDMS) elastomer. Polydimethylsiloxane (PDMS) can be in the form of an elastomer, a resin or a fluid. PDMS elastomers are formed using a cross-linking agent. PDMS is a typical gas permeable material due to its very high oxygen and carbon dioxide permeability, its light transmittance and its UV radiation resistance. These elastomers generally do not support the growth of microorganisms on their surface and therefore avoid uncontrolled biofilm growth and / or biofouling (light shading) that can reduce the efficacy of the device in biomass production. Optionally, biofilm growth can be promoted by utilizing a bio-support as described below and / or additional components. Furthermore, polydimethylsiloxane (PDMS) elastomers are flexible materials and elastic materials.

[0129] Polydimethylsiloxane (PDMS) can be chemically or mechanically modified to increase its gas permeability and / or change its properties. PDMS elastomers typically have the following properties: an oxygen permeability of at least 350 Barrer, at least 400 Barrer, at least 450 Barrer, at least 550 Barrer, at least 650 Barrer, at least 750 Barrer, suitably at least 820 Barrer and a carbon dioxide permeability of at least 2000 Barrer, at least 2500 Barrer, at least 2600 Barrer, at least 2700 Barrer, at least 2800 Barrer, at least 2900 Barrer, at least 3000 Barrer, at least 3100 Barrer, at least 3200 Barrer, at least 3300 Barrer, at least 3400 Barrer, at least 3500 Barrer, at least 3600 Barrer, at least 3700 Barrer, at least 3800 Barrer, suitably at least 3820 Barrer. The properties of the PDMS used in embodiments of the present application can be optimized by chemical, mechanical and process driven interventions related to, but not limited to, the molar mass of the polymer chain (M m ), the dispersity of the polymer (dispersity is the ratio of weight average molar mass to number average molar mass), the temperature and duration of heat treatment during curing, the ratio of crosslinker to PDMS, the chemical composition of the crosslinker, different end groups (such as methyl-, hydroxyl- and end-vinyl PDMS) that can affect the way PDMS structure formation of terminal chain loops during crosslinking.

[0130] In another embodiment, the film layer comprises bacterial cellulose. While bacterial cellulose has the same molecular formula as plant cellulose, bacterial cellulose has significantly different macromolecular properties and characteristics. In general, bacterial cellulose is more chemically pure in that it does not contain hemicellulose or lignin. In addition, due to high plasticity during shaping, bacterial cellulose can be produced on a wide variety of substrates and can be grown into almost any shape. In addition, bacterial cellulose has more crystalline structure than plant cellulose and forms unique ribbon-like microfibrils that are significantly smaller than those in plant cellulose, making bacterial cellulose more porous. The skilled person will be aware of a number of bacterial systems designed to optimise cellulose production, such as cellulose biosynthetic systems that can be expressed in, for example, Acetobacter sp., Azotbacter sp., Rhizobium sp., Pseudomonas sp., Salmonella sp., and Alcaligenes sp. of E. coli. Bacterial cellulose can be treated so that its surface provides a chemical interface to enable bonding with molecules.

[0131] The second layer can also be a film layer as defined above, i.e. a gas permeable layer, or can be constituted by a non-film layer comprising any suitable material, such as a natural or synthetic material. Suitably, the second layer is at least translucent, and typically transparent. The second layer is suitably breathable.

[0132] In typical embodiments, both the first and second layers are gas permeable film layers as defined herein.

[0133] In embodiments where the second layer is a non-film layer, the second layer can be or has been treated or machined to have a rough or porous surface. This enables microorganisms to attach to the material and encourages the development of a biofilm on the inner surface of the layer.

[0134] The non-film layer can be constituted by any suitable material. The material can be or can have been treated or modified to produce a rough or porous surface.

[0135] In suitable embodiments, the first and second layers are bonded together by adhesion and / or heat pressing. Heat pressing is the application of heat and pressure for a predetermined period of time to form a weld. Those skilled in the art will be familiar with suitable heat pressing techniques for this application. The precise temperature and duration required to bond together portions of the first and second layers will depend on the specific materials making up these two layers. Alternatively or additionally, a glue interface can be used to bond together portions of these two layers; once applied on these layers, the glue interface can be cured using heat pressing techniques, or can cure spontaneously at room temperature, or can cure using heat or pressure alone. As used herein, the term "glue interface" also includes the use of non-crystalline (non-vulcanized) polymers that can bond these two layers with heat pressing or wet pressing. As used herein, the related terms "glue interface", "adhesive" and "adhesive interface" are all synonymous and these three terms can be used interchangeably herein.

[0136] The glue interface thickness varies according to its composition, material and layer material. Suitably, the glue interface thickness is not less than 10 microns, suitably 20 microns, typically 50 microns. Typically, the glue interface thickness is not more than 5 mm, optionally 1 mm, suitably 600 microns, typically 200 microns.

[0137] More specifically, if the first and second layers are both made of polysiloxane and / or dimethylpolysiloxane (PDMS), these two layers can be bonded together by using a silicone adhesive that can be in the form of a viscous liquid gel, a layer, a layer tape and / or that can include all types of silicone adhesives that can cure below or above 22°C. After applying the silicone adhesive on these two layers, the bonded area is typically pressed for a determined period of time as indicated by the type of silicone adhesive and, if the type of silicone adhesive used also requires a heat curing, the heat is applied at a determined temperature and for a determined period of time as indicated by the type of silicone adhesive used.

[0138] Possible types of silicone adhesives include, but are not limited to: silicone glues and silicone adhesive layers such as VVB Birzer ADT-X (at 1 N / cm 2 between 15 N / cm 2 and at a temperature between 140°C to 180°C for 30 seconds to 60 seconds), Adhesives Research AR 4000 (at 25 microns to 100 microns) and Dow Corning Q7- 1580 (at 0.20 mm to 0.60 mm) and / or the like. IS-7876 silicone transfer adhesive (pressure sensitive adhesive that bonds under pressure and temperatures above 5°C). Alternatively, the silicone adhesive interface can be composed of a thin layer of uncured polysiloxane and / or dimethylpolysiloxane (PDMS) that can be mixed with its cross-linker and rapidly coated on the intended bonding area of these layers, followed by pressing and heat curing, thereby bonding the two sides together.

[0139] In some embodiments, a "glue interface" and / or "silicone adhesive" can be used to bond the two layers together in areas where the fluidic conduits are typically located. This bonding will create a control structure to control the flow of liquid media, thereby dividing or diverting the fluidic conduits into multiple conduits. The control structure / bonding areas increase the structural integrity of the device, facilitate the flow of liquid media, and enhance the control of the device volume, thickness, and shape when the cell expands due to fluid pressure.

[0140] In some embodiments, "structural components" can be placed between the two layers on the bonding areas to enhance the overall cell structure and better control the cell thickness and shape when the cell expands. The thickness of these structural components will be equal to the intended cell thickness, and their length and profile shape will at least partially follow the intended bonding profile and shape. The structural components can be bonded to the two layers by adhesion and / or heat pressing. The exact temperature and duration required to bond the portions of the first and second layers to the structural components will depend on the specific materials used for the two layers and the structural components. Alternatively or additionally, a glue interface can be used to bond portions of the two layers to the structural components.

[0141] The materials of the structural components can include, but are not limited to, flexible polymers such as silicone, polysiloxane, polysiloxane elastomer, polydimethylsiloxane (PDMS), and PDMS elastomer, and rigid polymers including optically transparent rigid polymers.

[0142] Alternatively or additionally, a glue interface can be used to bond portions of the two layers with the structural components between the two layers on the desired bonding areas. Once the glue interface is coated on the layers and the structural components, the glue interface can be cured with heat pressing techniques or can spontaneously cure at room temperature or can be cured using heat and pressure alone.

[0143] In some embodiments, structural components, with or without glue interfaces, bonded to both layers can be used to bond the two layers together in areas where the fluidic conduits are normally located. This bonding creates control structures to control the flow of liquid media, dividing the fluidic conduits into multiple fluidic conduits. The control structure / structural component bonding areas increase the structural integrity of the device, facilitate the flow of liquid media, and / or enhance the control of the device volume, thickness, and shape as the cell expands due to fluid pressure.

[0144] The glue interfaces and structural components are suitably translucent and typically transparent.

[0145] In suitable embodiments, the cell can be made from a single sheet of gas permeable membrane that is folded over on itself, and the two ends of the single sheet can be bonded, thereby defining the cell. The bonding method is the same as described above. There can be additional bonding between the two sides of the folded layer to create control structures as described above. The folded edges can be used as a point of attachment to a mounting structure or manifold; the folded edges can also be clamped or otherwise reinforced.

[0146] In embodiments, the cell can be made from a single layer of gas permeable membrane that is extruded into a tubular shape. In this embodiment, there is no need to bond the ends, as it is already closed on both sides, thereby defining the cell. However, there can be bonding between the two sides of the same extruded layer to create control structures as described above. The edges can be used as a point of attachment to a mounting structure; the folded edges can also be clamped or reinforced.

[0147] Additional component

[0148] In some embodiments, the device of the present invention includes an additional component (e.g., 14, 16, etc.) located within the pocket or cell. The primary purpose of this component is to provide a surface for microorganisms to attach to, thereby forming a biofilm.

[0149] This component can comprise any suitable material. The material can be or can have been treated or modified (e.g., machined or coated) to produce a rough or porous surface. Alternatively, the additional component can be entirely porous, comprising any suitable porous material such as a sponge material, a protein, a scaffold matrix, or a mesh.

[0150] The additional component can be positioned anywhere within the cell of the device. In some embodiments, the additional component is in contact with the interior of one or both of the outer layers of the device. The component can cover the entire interior surface of these layers or only a portion thereof.

[0151] The additional component is suitably translucent and typically transparent.

[0152] In some embodiments, additional components can be coated on one or both sides with a biological support. In such an arrangement, microorganisms attach to the biological support rather than to the surface of the additional component, and thus the additional component need not be porous or have a rough or porous surface; the additional component can be made of any material that can support a coating.

[0153] Biological support

[0154] In embodiments, the device of the application further comprises a biological support located within the pocket formed by the first and second layers. The biological support is a material that provides a physical structure or chemical interface for the attached photosynthetic microorganisms. The biological support can be modified to enable the attachment of microorganisms.

[0155] The biological support optionally comprises a coating such as a protein coating and / or a chemical coating. Typically, the thickness of the biological support coating is no less than 0.1 nm, suitably 0.5 nm, optionally no less than about 50 nm. In embodiments, the thickness of the biological support coating is 1 nm. In some embodiments of the application, the thickness of the biological support can be up to 30 microns and even up to 50 microns.

[0156] Suitably, the biological support is at least translucent and typically transparent.

[0157] As mentioned above, light can reach the device from a single direction or from multiple directions. Photosynthetic microorganisms located within the device can be attracted (e.g. via phototaxis) to the side of the device closest to the primary light source and can attach to the inner surface of the side of the device, forming a biofilm. However, this can not be desirable as the formation of a biofilm on the inner surface of the portion of the device closest to the primary light source can prevent light from reaching other portions of the device. The presence of a biological support component of the device allows for control of the location of microorganism growth within the device and facilitates growth in the desired location. The biological support component can be used to facilitate the formation of a biofilm in a region of the device that will allow for the best passage of light through the device and thus facilitate maximum photosynthetic efficiency of the photosynthetic microorganisms contained within the device and thus maximise biomass generation and regeneration efficiency. The location of the biological support within the pocket can vary depending on the specific constitution and arrangement of the device. For example, the biological support can be positioned in close proximity to or in contact with the inner surface of either or both of the first and second layers. The biological support can partially or completely cover the inner surface of either or both of the two layers. Alternatively, the biological support can be centrally located within the pocket (i.e. not in contact with the inner surface of the first and second layers). In typical embodiments, if light reaches the device primarily from a single direction, the biological support is used to enhance growth and biofilm formation on the opposite side furthest from the primary light source.

[0158] In embodiments of the application comprising an additional component polymer or porous component as discussed above, the additional component can be partially or completely encased by the bio-support.

[0159] Microorganism

[0160] It is envisaged that the microorganisms contained within the units of the device are capable of photosynthesis. Any microorganism capable of photosynthesis is referred to herein as a photosynthetic microorganism. In suitable embodiments, the photosynthetic microorganism is selected from the group consisting of microalgae (such as green algae, green-blue algae, golden algae and red algae), phytoplankton, flagellate algae, diatoms, bacteria and cyanobacteria such as Spirulina. The microorganisms can be wild-type or genetically modified strains. A single device according to embodiments of the application can comprise one or more different types of microorganism.

[0161] Typically, at least one microorganism is of the genus Haematococcus, Haematococcus pluvialis, Chlorella, Chlorella autotrophica, Chlorella vulgaris, Trebouxia, Synechococcus, Synechococcus elongatus, Synechocystis, Arthrospira, Arthrospira platensis, Arthrospira maxima, Spirulina, Chlamydomonas, Chlamydomonas reinhardtii, Gleocapsa, Klebsormidium, Pyramimonas, Pyramimonas amylifera, Cyanophora, Cyanophora parica, Oscillatoria, Nostoc, Nostoc sphaeroids, Nostoc commune, Anabaena, Anabaena azollae.

[0162] In embodiments in which the liquid medium passing through the channels in the device comprises saltwater, Dunaliella salina and Synechococcus marinus are typical microorganisms.

[0163] Coating for preventing growth and attachment of microorganisms

[0164] In order to control the location of microbial adhesion and growth to form a biofilm within the device and the location where the microorganisms do not grow, any component of the device described herein or a portion thereof can be coated with a hydrophobic, hydrophilic or antimicrobial coating or can be machined or otherwise physically or chemically transformed to have a hydrophobic, hydrophilic or antimicrobial characteristic. As used in this context, the term "portion" means a sufficient amount of the component to provide the component with the hydrophobic, hydrophilic or antimicrobial characteristic.

[0165] The antimicrobial agent can have a physical modification such as a rough surface or a chemical modification such as a coating.

[0166] Suitable antimicrobial agents include organosilanes, silver, silver alloys, copper and copper alloys.

[0167] Typical hydrophobic coatings include Teflon TM , PTFE, poly(methyl methacrylate) (PMMA), graphene and carbon nanotubes. As the skilled person will be aware, "superhydrophobic" surfaces can also be created, for example using fluorocarbons.

[0168] The hydrophilic coating can also prevent microbial attachment and biofilm formation. Suitably, such a hydrophilic coating is based on highly hydrated zwitterions such as glycine, betaine and thiobetaine.

[0169] These coatings prevent microorganisms located within the unit from adsorbing onto the inner surface of the component. In this way, the location where microbial growth and attachment occurs within the device can be controlled. This is advantageous in optimising the passage of light through the device, which results in optimal photosynthesis by the photosynthetic microorganisms located within the device, and thus optimal biomass production. Controlling the location of microbial growth and biomass formation in this way also aids and facilitates optimal harvesting of the biomass from the device.

[0170] For example, it can be desirable to prevent microorganisms from attaching inside the membrane layer and forming a biofilm, since the formation of a biofilm can prevent light from reaching the interior of the pockets of the device. This can be particularly important in embodiments where the membrane layer is positioned on the side of the device closest to the light source. Thus, in typical embodiments of the application, at least a portion of the membrane layer inside (i.e. the side of the membrane layer inside the pockets formed by the two outer layers) is coated with a hydrophobic, hydrophilic or antibacterial coating or can be machined or otherwise physically or chemically transformed to have hydrophobic, hydrophilic or antibacterial properties in order to prevent microbial growth and attachment.

[0171] In other suitable embodiments, the inner surface of the second layer can be coated with a hydrophobic, hydrophilic or antibacterial coating or can be machined or otherwise physically or chemically transformed to have hydrophobic, hydrophilic or antibacterial properties.

[0172] In instances where light reaches the device primarily from one direction, it is typical to promote microbial growth on the inner surface of the outer layer located furthest from the main light source.

[0173] Fluid conduit

[0174] One or more fluid conduits suitable as channels for directing liquid media and water are arranged within the unit to optimise the fluid flow rate through the unit, having an inlet (1) and an outlet (2). In particular embodiments, these fluid conduits can comprise liquid media conduits. Suitably, but not limitingly, the fluid rate is not less than about 1 ml / min, typically 50 ml / min, and optionally 200 ml / min. Flow rates of up to 30 L / min, suitably 10 L / min, and about 1 L / min are possible depending on the size and configuration of the system. The fluid velocity can vary according to the photosynthetic activity of the photosynthetic microorganisms contained within the device at a given time, which can depend on external factors such as temperature and light intensity.

[0175] Additionally, the fluid flow rate can vary with the width and thickness of the fluidic channel and the mounting orientation of the device.

[0176] Maintaining a constant low rate also helps prevent microbial attachment to the membrane layer and / or to additional components not specifically intended to support biofilm formation. The fluid flow rate can be dynamically changed over very small and / or very large time periods (seconds, minutes, hours, days).

[0177] In typical embodiments, one or more fluidic conduits are configured to direct flow and facilitate the exchange of liquid media between the cell and a source of liquid media.

[0178] This is suitably accomplished by a control structure positioned within the cell and forming a barrier to the passage of liquid media through the cell, thereby creating a defined channel. The control structure can be made of any suitable translucent or more typically transparent material. Alternatively or additionally, the control structure can be formed by bonding discrete regions of the two outer layers. Such bonding can be accomplished using a heat press or a glue interface. The control structure / bonded regions increase the structural integrity of the device, facilitate liquid media flow, and increase control over the device thickness and shape when the cell expands due to liquid pressure.

[0179] Alternatively or additionally, the control structure can be formed by bonding discrete interior regions of the two outer layers to a structural component. Such bonding can be accomplished using a heat press or a glue interface. The control structure / structural component bonded regions increase the structural integrity of the device, facilitate liquid media flow, and increase control over the device volume, thickness, and shape when the cell expands due to liquid pressure.

[0180] The arrangement of fluidic conduits creates spaces in which liquid media flow is optimized. The fluidic conduits can also distribute liquid media evenly throughout the cell, thereby maintaining similar liquid media flow rates. In suitable embodiments, one or more fluidic conduits are configured to allow removal of microorganisms / biomass from the cell and / or to allow liquid media with microorganisms to flow through an illumination path. The optimized configuration of fluidic conduits also facilitates temperature control within the device. Specific arrangements of channels are exemplified in detail below.

[0181] The device (or module comprising multiple cells) is connected to a liquid media supply via one or more inlets.

[0182] The device can be connected to the liquid media supply using additional attachment components or abutment mechanisms (e.g., rigid fixtures, flexible fixtures, clamps, pressure fits connected by conduits).

[0183] In separate embodiments of the invention, the minimum requirement for the device is to include a single fluidic conduit with a single opening that serves as both an inlet and an outlet.

[0184] A second aspect of the present invention relates to a photobioreactor module. The photobioreactor module comprises a plurality of devices as defined above.

[0185] In typical embodiments of this aspect of the present invention, each individual unit is connected to one or more devices via the liquid medium channel inlet / outlet. Additional attachment means or abutment mechanisms (e.g. rigid fixation, flexible fixation, clamping, pressure fit by conduit connection) can be used to connect the plurality of devices to each other via the liquid medium channel inlet / outlet.

[0186] Additional attachment means or abutment mechanisms (e.g. rigid fixation, flexible fixation, clamping, pressure fit by conduit connection) can be used to connect the individual device and / or the plurality of devices to the liquid medium supply.

[0187] Suitably, the module is manufactured as a single modular unit. Additional attachment means or abutment mechanisms (e.g. rigid fixation, flexible fixation, clamping, pressure fit by conduit connection) can be used to connect the plurality of photobioreactor modules to each other via the liquid medium channel inlet / outlet.

[0188] Additional attachment means or abutment mechanisms (e.g. rigid fixation, flexible fixation, clamping, pressure fit by conduit connection) can be used to connect the individual modular unit and / or the plurality of modular units to the liquid medium supply.

[0189] Artificial light source

[0190] The device of the present invention can receive light from external natural or artificial sources. Alternatively, to increase the amount of light available to the photosynthetic microorganisms contained within the pocket, an artificial light source can be positioned within the device.

[0191] Typically, the artificial light source is selected from the group consisting of a light emitting diode (LED) or an organic light emitting diode (OLED), or a light guide fiber or optical fiber embedded within the device and connected to an external natural or artificial light source.

[0192] Suitably, the artificial light source is designed and / or controlled to emit electromagnetic radiation (light) of a specific wavelength that follows the photosynthetically active radiation (PAR) requirements of the photosynthetic microorganisms contained within the device.

[0193] In a suitable embodiment illustrated in Figure 33, the artificial light source is partially or completely embedded within one or more translucent or transparent control structures / structural components located between the first and second layers.

[0194] Furthermore, the optical fiber and / or optical fiber cable connected to the external light source can be partially or completely embedded within one or more translucent or transparent control structures / structural components located between the first and second layers.

[0195] Shape and size

[0196] The following features can apply to a device comprising a single unit according to embodiments of the application or to a module comprising multiple units according to other embodiments.

[0197] The shape can resemble a squashed tube when the unit expands due to liquid medium pressure, whereby the optimal thickness and / or volume can vary.

[0198] Suitably, the overall thickness of the device, unit or module of the application is as thin as possible when expanding due to liquid medium pressure to enable light to travel through the device, thereby maximizing the photosynthetic capacity and efficacy of the biomass production of the device. Typically, the thickness is not less than 2 mm, suitably 5 mm, typically 10 mm. Typically, the thickness is not more than 100 mm, suitably 60 mm, typically 35 mm.

[0199] By using external containment structures such as a grid or thin solid material and / or by stretching the unit from opposite bonding areas and / or folding areas and / or edges of the unit,

[0200] The shape of the unit can be controlled to be flat or nearly flat (having a rectangular cross-section instead of a tubular cross-section).

[0201] The depth and width of the device or modular photobioreactor are also important for controlling the temperature within the device, as these effects can be a function of the amount of liquid medium contained within the device. A device with a greater depth and width will be able to accommodate a greater number of fluid conduits and a greater volume of liquid medium.

[0202] The length and width of the fluid conduits vary with respect to each application and unit shape, so the fluid conduits can have any reasonable length and width. As an example, the length of the fluid conduits within a linear unit is not less than 5 cm and not more than 10 meters. Suitably, the width of the fluid conduits within a unit is not less than 1 cm, typically 3 cm, and not more than 20 cm, suitably 10 cm.

[0203] The two- or three-dimensional shape of the device or module is not limited; it can be any convenient shape, such as a rectangular shape or any shape having a constant width, any shape that narrows at the top and bottom near the inlet and outlet portions, or a leaf shape, a circular shape, an oval shape, a cross shape, a square, a streamlined or star shape. Examples of suitable shapes are discussed in detail below.

[0204] A third aspect of the application relates to a method of using a device for biomass production or a photobioreactor module as defined herein.

[0205] In addition, the device can also be used to generate oxygen and / or remove environmental pollutant gases such as carbon dioxide from the atmosphere.

[0206] Mechanism of action

[0207] Due to the membrane layer of the unit, gas exchange occurs through the membrane between the liquid medium contained within the unit and the atmosphere outside the unit. Figure 34 As shown, any kind of permeable gas can be exchanged across the membrane in either direction; that is, gas can permeate from the liquid medium to the external atmosphere (5) or from the external atmosphere to the liquid medium (6). The gas permeability will vary relative to the partial pressure difference of the permeable gas between the inside and outside of the unit. In a suitable embodiment of the invention, carbon dioxide is consumed by microorganisms in the liquid medium within the device, which reduces the carbon dioxide concentration in the liquid medium. Due to the pressure difference generated between the inside and outside of the device, new carbon dioxide permeates through the membrane from the external air inside the device. Furthermore, in a typical embodiment, oxygen produced by the microorganisms permeates from the liquid medium inside the device through the membrane to the outside of the device.

[0208] This membrane-driven gas transfer advantageously allows for a significant reduction in the costs associated with ventilation, replacing ventilation via more complex and expensive gas delivery systems with passive membrane-driven gas permeation that requires no additional energy input. It is known that carbon dioxide is a fundamental component of photosynthesis, and that biomass production rates can be greatly increased if high light levels are present and carbon dioxide is efficiently delivered to microorganisms within the liquid medium, sustaining their gas requirements. On the other hand, the oxygen produced by microorganisms is typically dissolved in the liquid medium, increasing the oxygen concentration in the device. It is known that high levels of dissolved oxygen in the liquid medium slow down photosynthetic processes and thus reduce biomass production rates.

[0209] Effective consumption of oxygen from the liquid medium within a standard photobioreactor can be difficult and costly to achieve because dissolved oxygen needs to be driven from the liquid medium to the outside of the photobioreactor through vents (primarily by utilizing bubbles in the liquid medium).

[0210] In the most standard photobioreactors, the liquid medium flows for an extended period within the non-membrane conduit before reaching the vents, bubbling zone, air inlet, and / or water tank. Consequently, the liquid medium can have extremely high levels of dissolved oxygen and extremely low levels of carbon dioxide, leading to a significant reduction in biomass generation rates. Using a gas-permeable photobioreactor allows for continuous gas exchange between the liquid medium within the device and the outside environment during the flow process.

[0211] The advantage of performing this membrane-driven gas transfer in a photobioreactor technology is an improved adaptability, a reduced cost and an increased quality of the microbial culture in the liquid medium by effectively removing oxygen.

[0212] Auxiliary system

[0213] The device can be connected to an auxiliary system. Depending on the application of the device, the auxiliary system can have any degree of complexity and be composed of any type of auxiliary components.

[0214] In a suitable embodiment of the application, the device is connected to an auxiliary system mainly composed of conduits, water tanks, pumps, valves, biomass separators, artificial lighting systems (especially if natural light is not present), water temperature control systems, sensors and computers.

[0215] The conduits and reservoirs (water tanks) can be of any type and be composed of any suitable material.

[0216] The pumps can also be of any type, typically the pumps are peristaltic pumps, since the peristaltic pump used is the only component in contact with the liquid medium, it can reduce the risk of contamination of the liquid medium and cell breakage of the microorganisms used.

[0217] The biomass separators can be of any type known to the skilled person; suitably, the biomass separators are centrifuge-type biological separators, filtration systems comprising small aperture meshes and / or sedimentation devices and / or purification processes.

[0218] The water temperature control can be of any type known to the skilled person; typically, it comprises heating components suitably installed near a portion of the conduits and / or on the water tanks. The heating components can be of any type and suitably can comprise heat exchange mechanisms.

[0219] The artificial lighting system can use any artificial light source known to the skilled person, suitably the lighting system comprises LEDs, typically the artificial light sources are designed and / or controlled to emit electromagnetic radiation (light) of specific wavelengths corresponding to the photosynthetic active radiation (PAR) requirements of the photosynthetic microorganisms contained within the device.

[0220] Suitable sensors and computers are described below.

[0221] Figure 35A suitable system comprising multiple photobioreactor units (105) is shown for one embodiment of the application (90). Liquid medium comprising photosynthetic microorganisms in a reservoir (91) is delivered through an inlet (1) by a pump (92) into a rectangular photobioreactor unit (105). The liquid medium passes through the unit (105) along a tortuous path where light from artificial light sources (93) or natural light sources reaches the microorganisms in the liquid medium to promote photosynthesis, while gas transfer between the liquid medium in the unit (105) and the outside air occurs through the membrane layers of the unit substantially as shown for example in Figure 34 The liquid exits the unit through an outlet (2) and reaches a 3-way valve (94) which directs the liquid medium back into the reservoir (91) closing the loop. Sensors (95) in the reservoir (91) measure values of microorganism culture parameters and send outputs to a computer which then controls the operation of components of the auxiliary system such as pumps, valves, artificial light systems, temperature control systems, biomass separators, etc.

[0222] When the biomass concentration in the liquid medium reaches a desired level, the 3-way valve (94) directs the flow into a biomass separator (96) which separates the biomass from the liquid medium, the separated biomass travels to a receptacle (97) for additional processing while the liquid medium is directed back into the reservoir (91). This action of directing the flow into the biomass separator can be performed periodically and for a predetermined period of time before the valve (94) changes the flow path into the reservoir (91) again. This timing can be optimized with respect to each application, the microorganisms used, the surrounding environment and the location of the installation.

[0223] Nutrients can be periodically added (98) to the system, directly into the reservoir (91). Water and / or microorganisms in the liquid medium or cleaning fluids can be similarly introduced.

[0224] A variety of other system components can be utilized, as an example, controllable pressure valves or pressure regulators (99) can be placed in the system, in this example, the pressure valves can control the volume changes of the units through changes in the liquid pressure. Some valves (102) can control the flow rate into the units.

[0225] Supplemental air and / or carbon dioxide enriched air and / or other gases can be optionally introduced (101) into the main conduit as needed. Air vents can be installed in the conduit to remove air that can accidentally enter the hydraulic system for example during installation of the system, and are typically located in the highest position of the system to facilitate the expulsion of unwanted air.

[0226] The cleaning procedure can be actuated to clean and / or disinfect units and / or conduits and / or tanks and / or all auxiliary systems. The "cleaning solution" can be made from any compound known to the technician. It may include ethanol, water, brine, detergent, bleach, surfactant, alkali, or any suitable cleaning ingredient. The cleaning solution can enter the system through specific conduits located at any point in the system and can exit at any point in the system to allow cleaning only specific locations (if necessary) rather than cleaning the entire system.

[0227] Holding and mounting solution

[0228] One or more devices of the present invention can be installed in all orientations and locations that conform to the environmental characteristics of their intended application and / or their installation location. The unit of the device may have reinforced edges positioned adjacent to the seal and pocket defined therein, suitably located at the external adhesive area. Reinforced panels are adapted for attachment to an external mounting structure. In a preferred embodiment, the edges of the unit are reinforced with multiple anchor points, thereby enabling attachment to an external mounting structure such as a frame or support. The reinforced edges can also serve to strengthen the structure of the unit and potentially control its thickness and / or volume when inflated by the liquid medium therein.

[0229] If installed in a vertical, substantially vertical, and / or substantially inclined position, the device or devices may extend from the mounting structure through inlet or outlet conduits, reinforced edges of the unit, or through a reinforced suspension structure. The device or devices may be situated on a bed that provides a mounting interface between the device and the ground, which is particularly suitable for horizontal, substantially horizontal, and / or substantially inclined locations (e.g., on a sloping roof of a building). The support bed may be constructed of mirrors or other reflective materials to enhance the collection of light through the unit of the device.

[0230] The one or more units are composed of a single folded film layer ( Figure 32a , Figure 32b In the embodiment made of ), the folded edge (86) can be used as a fixing point to the mounting structure, and the folded edge can be clamped or reinforced.

[0231] Additional component layer

[0232] In another embodiment of the invention, such as Figures 5 to 9 As shown, the additional components (15, 16) can be placed inside the cell, in contact with one or more phases in the outer membrane layer, or they can be in the form of a third layer (87), such as Figure 33a and Figure 33bAs shown, the third layer can be held in place by bonding it to the two outer film layers through the adhesive interface (82). Optionally, as Figure 33b As shown, the structural component (83) can be bonded between the additional component layer and the outer membrane layer. As described above, the additional component layer (87) can divide a single fluid conduit in two at an orientation different from the orientation created by the control structures (27, 37, 47).

[0233] Extruded version

[0234] In one embodiment, the unit may be formed by extruding into a tubular shape. Figure 38 It is made of a single-layer gas-permeable membrane. This embodiment eliminates the requirement for adhesive ends because it is already closed on both sides, thereby defining the pocket. Adhesion between the two sides of the same extruded layer can be used to create the control structure as described above. Optionally, the edges (86) can be used as fixing points to the mounting structure, and the folded edges can also be clamped or reinforced.

[0235] Non-membrane option .

[0236] In another embodiment of the present invention ( Figure 39 In this embodiment, the outer layer of the cell includes a membrane layer (11) and a non-membrane layer (18). The non-membrane layer (18) can be made of any material, suitably flexible or non-flexible translucent material, optionally transparent material, or optionally clear material such as glass. The non-membrane layer (18) is introduced when the gas permeability through the membrane layer (11) is sufficiently high to provide ideal gas transfer between the liquid medium and the atmosphere outside the cell (10). This embodiment may include additional components and configurations as described in any of the other embodiments above.

[0237] Application

[0238] The device of this invention can be used in a variety of applications. These applications can be of any type requiring biomass production, carbon dioxide isolation, oxygen production, nitrogen oxide or other gas isolation, wastewater treatment, or even aesthetic applications. The device can be used indoors and / or outdoors.

[0239] Suitable applications of the device of the present invention can be any indoor and / or outdoor architectural application, including but not limited to building facades, roofs, sunshades, shading structures, windows and / or interior ceilings, interior walls, or interior floors. In these applications, the generated oxygen can be used within the building and / or carbon dioxide can be absorbed from the interior and / or exterior of the building.

[0240] Suitable applications of the device of the present invention can be used with any lighting system and / or lighting fixture, including but not limited to interior lighting systems such as ceiling, floor, wall, desk, etc., suspended lighting, technical lighting, decorative lighting, outdoor lighting, street lighting, or advertising lighting fixtures.

[0241] In such applications, the artificial light source provided from the lighting system can provide most of the light required by the microorganisms to perform photosynthesis, and the oxygen produced can be used inside the building and / or the carbon dioxide can be absorbed from the inside and / or outside of the building.

[0242] Additional suitable applications of the device of the present invention can be intensive biomass production applications, including but not limited to outdoor intensive biomass production plants using mainly natural light sources, indoor intensive biomass production plants using artificial light sources and / or natural light sources such as greenhouses.

[0243] Further suitable applications of the device of the present invention can be used with infrastructure, including but not limited to urban infrastructure, highways, bridges, industrial infrastructure, cooling towers, roads, underground infrastructure, traffic sound barriers, silos, water towers, or airplane hangars.

[0244] Other suitable applications of the device of the present invention can be combined with water treatment plants, including but not limited to wastewater treatment plants, municipal wastewater treatment plants, sewage anaerobic digestion treatment, manure anaerobic digestion treatment, anaerobic digesters, or incinerators.

[0245] The device of the present invention can remove pollutants and / or nutrients (such as nitrates or phosphates) directly from wastewater streams that can be diverted within the unit. This is advantageous in wastewater treatment applications and building / industrial applications that require partial treatment and / or pre-treatment of the water. In such embodiments, the water containing pollutants that are toxic to the microorganisms within the device of the present invention should be treated to remove these pollutants prior to introduction into the device.

[0246] The device of the present invention can be installed in proximity to any type of industrial processes and / or agricultural processes and / or farming processes and / or intensive agricultural processes (intensive fish farming) and / or manufacturing processes and / or refinery processes and / or energy production processes, where exchange of any kind of compounds and gases can occur between the device (with auxiliary systems) and these processes.

[0247] Continuous harvesting

[0248] An advantage of some embodiments of the present invention is that biomass can be continuously generated within the unit and can be harvested on a continuous basis.

[0249] Biomass accumulates in the liquid medium within the cells, in the region of the biofilm formed on the surface of the components of the device including the bio-support component, additional components, or on the inner surface of the two outer layers. Biomass can be harvested directly from the liquid medium and optionally also using chemical treatment to facilitate detachment of biomass from the interior of the device. To purge the device and release the biomass, the liquid medium enters the device via one or more inlets, passes through one or more channels and exits the device via one or more outlets, carrying with it the biomass in the flow. The outlets can be connected to suitable receptacles to receive the harvested biomass.

[0250] In embodiments where biomass is intentionally grown within the device, the biofilm serves to provide a fixed surface of active photosynthetic microorganisms that prevents some of the microorganisms from being washed away when the device is flushed. This facilitates rapid generation of biomass and allows for continuous harvesting of the biomass generated in the device. This enables the device to be rapidly regenerated / replenished with biomass, as the microorganisms that remain within the device can continue to generate biomass via photosynthesis (provided that the light conditions allow for photosynthesis). Furthermore, to generate more biomass, new / additional microorganisms do not need to be introduced into the pouch after the biomass has been harvested.

[0251] Batch harvesting

[0252] Alternatively, biomass can be harvested intermittently on a batch basis. For example, biomass can be harvested frequently on an hourly, daily, weekly basis.

[0253] Sensor

[0254] Embodiments of the present invention and / or ancillary systems can include embedded sensors that can be used, for example, to monitor chemical concentrations in the liquid and / or gas, such as carbon dioxide concentration and / or oxygen concentration; and / or to monitor temperature and other environmental and biological parameters such as toxicity levels and / or to monitor biomass concentration in the liquid medium.

[0255] The sensors can be fully or partially embedded in the device, in the water tank (18) of the ancillary system and / or in the control structure and / or attached to the interior or exterior of the outer layers or on the surface of the interior additional components.

[0256] The sensors can permit monitoring of the environment inside the pouch of the cells of the device to enable control of parameters including, but not limited to, liquid medium flow rate, liquid medium mass, nutrient levels, temperature, biomass extraction rate, and illumination intensity. The purpose of the control is to optimize the photosynthetic efficiency of the photosynthetic microorganisms contained within the device and, therefore, the efficiency of biomass generation.

[0257] The apparatus of the present invention is illustrated by the following arrangements, but is by no means limited to these arrangements.

[0258] Two membrane layers

[0259] Figure 1 The diagram illustrates an apparatus according to a specific embodiment of the invention. The apparatus comprises a unit (10) having two membrane layers (11, 12), an internal space (13) defined by the two membrane layers, an inlet (1), and an outlet (2). The two membrane layers (11, 12) may have the same or different compositions. Biological growth may occur within one or both of these membranes, or microbial growth may not occur within either of the membranes.

[0260] In suitable embodiments, the biosupport (15) is present within one or two layers. The biosupport promotes microbial growth and biofilm formation. Figure 3 The arrangement of the biological support within the two membrane layers (11, 12) is shown in the figure. Figure 4 The arrangement of biological supports within a membrane layer is shown.

[0261] Another embodiment of the device includes a unit (10) comprising two membranes (11, 12) and may also include an additional component (14) as defined above, which may be located in a pocket (13) defined by the two layers. Figure 2 This arrangement is illustrated in the figure. It is likely desirable that microorganisms attach to the additional components rather than to the inner surface of the membrane layers (11, 12). The fluid flow rate can be high enough to prevent microbial growth on the membrane layers. However, the inner surface of the membrane layers (11, 12), or a portion thereof, can be hydrophobic or can be coated with a hydrophobic, hydrophilic, or antimicrobial coating, or can be machined or otherwise physically or chemically transformed to have hydrophobic or antimicrobial properties.

[0262] like Figure 5 and Figure 6 As shown, the additional component (14) can optionally be covered on one or both sides with a biological support (15). In this embodiment, the microorganisms attach to the biological support rather than to the surface of the additional component, so the additional component does not need to be porous or have a rough or porous surface.

[0263] Figure 7 , Figure 8 and Figure 9A device comprising a unit (10) is shown, the unit having a first membrane layer (11) and a second membrane layer (12) and an additional component (16) located in a pocket formed by the two layers. In this embodiment, the additional component (16) is made of a porous material and can be attached to either membrane layer or both membrane layers or can be located within the pocket (13).

[0264] One membrane layer and one non-membrane layer

[0265] As mentioned above, a device comprising a unit (10) according to some embodiments of the present application can have one membrane layer (11) and one non-membrane layer (18). Figure 39 Such an arrangement is shown in. In this embodiment, the non-membrane layer can be modified or treated to create a rough surface to enhance the attachment of microorganisms and the formation of biofilm.

[0266] If the device is primarily illuminated from a single direction, the membrane layer can be located on the side of the device closest to the primary light source and the non-membrane layer can be located on the side of the device furthest from the primary light source. Alternatively, the non-membrane layer can be located on the side of the device closest to the primary light source and the non-membrane layer can be located on the side of the device furthest from the light source.

[0267] As described above in relation to the two membrane layer arrangement, a device comprising a membrane layer and a non-membrane layer can also comprise an additional component which can be encased, as defined above, which can be located in a pocket (13) formed by the two layers (11, 12).

[0268] Configuration of fluid conduit

[0269] Figure 10 A simple streamlined version of an embodiment of the present application with one fluid conduit with inlet (1) and outlet (2) on opposite sides is shown in. In this front view illustration of the device (20), liquid medium flows in via the inlet (1) at the top, through the space within the pocket (23), and out via the outlet (2) at the bottom on the device.

[0270] Figure 11 A simple streamlined version of an embodiment of the present application with two fluid conduits and a single control structure is shown in. In this front view illustration of the device, one unit (20) is provided, the central portion (27) representing the area where the two outer layers are bonded together and / or where the control structure is located. Fluid flows in via the inlet (1) at the top and is divided into two channels (23) to the left and right of the bonded area / control structure. Liquid medium from the two channels (23) exits via the outlet (2) at the bottom of the device.

[0271] Figure 12A streamlined version of an embodiment of the application with multiple flow control structures (27) is shown in FIG. 6. In this front view illustration of the device (20), the central portion has both linear and streamlined flow control structures, fluid flows in via an inlet (1) at the top and is divided into four channels (23). Fluid from all channels exits via an outlet (2) at the bottom of the device.

[0272] Figure 13 A streamlined version of an embodiment of the application (20) with multiple dimpled circular flow structures (28) is shown in FIG. 7. In this front view illustration, the pocket includes an array of multiple flow control structures (28). These structures can be circular or any other convenient shape. These control structures create turbulent flow and multiple different paths through which liquid media can flow. As in the previous example, in this arrangement, the inlet (1) is at the top of the illustration and the outlet (2) is at the bottom.

[0273] Figure 14 An arrangement (20) designed to increase the surface area of the device that is exposed to light to increase the photosynthetic capacity and efficacy of the device for biomass generation is shown in FIG. 8. In this example, there are multiple protrusions (29) each including flow control structures (27) as described above.

[0274] Figure 15 A different version of the device including a cell (30) is shown in FIG. 9. In this illustration of the device, the inlet (1) and outlet (2) are positioned adjacent to each other on the same side of the device. There are linear flow control structures that form a single channel (33) within the cell and create an optimized flow path. Flow is directed down through the device from the inlet (1) at the top and then loops back to exit the device via the outlet (2) also at the top of the device.

[0275] Figure 16 A version of the device is also shown in which the inlet and outlet are positioned adjacent to each other on the same side of the device. In this front view illustration of the device, the central portion has both linear and streamlined flow control structures (37) that create two channels (33). Flow is directed down through the two channels from the inlet (1) at the top and then loops back to exit the device via the outlet (2) also at the top of the device.

[0276] Figure 17A typical configuration of a device of the present application comprising a cell (40) is shown. The device is linear (substantially similar to a circular parallel tubular or squashed / elliptical pipe shape). This shape is easy to manufacture and is particularly suitable for arranging with multiple other devices in a modular fashion. In this illustration, the width of the device is reduced at the top and bottom near the inlet (1) and outlet (2). However, this need not be so; the width can be uniform along the length of the device, or the width can vary (increase or decrease) along the length. The length can also vary depending on the desired application of the device. In this illustration, there is one fluid conduit with the inlet (1) and outlet (2) located on opposite sides.

[0277] Figure 18 A device comprising a cell (40) similar to that described in Figure 18 above is shown, but with linear control structures (47) introduced in the central portion of the device creating bifurcated channels (43). Fluid flows in via the inlet (1) at the top and turns along the two channels (43). Fluid from the two channels exits via the outlet (2) at the bottom of the device.

[0278] Figure 19 A device comprising a cell (40) similar to that described in Figure 20 above is shown, but with multiple flow control structures (48) introduced creating multiple different paths that liquid media can flow through (the multiple flow control structures can be circular or any other convenient shape). In the arrangement shown here, the inlet is at the top of the device and the outlet is at the bottom.

[0279] Figure 20 A version of a device comprising a cell (50) with four branches with an inlet (1) and outlet (2) is shown. The inlet and outlet can be positioned at any of the four locations shown in this illustration. There is a control structure (57) at the center of the four branches for regulating the flow through the device and its structure. This arrangement (50) can be used to join multiple modules, cells or devices together, or it can be used by itself or in an array with other devices of the same shape.

[0280] Figure 21 A different arrangement with multiple protrusions (49) is shown similar to the streamlined device arrangement shown in Figure 14 above. The inlet is at the top of the device (1) and the outlet (2) is at the bottom. There are multiple channels for liquid media to flow through within the device. This arrangement is designed to increase the surface area of the device that is exposed to light to increase the photosynthetic capacity and efficacy of the device for biomass generation.

[0281] Figure 22A linear device is shown comprising a unit (60) with a single channel created by a linear flow control structure (67). Both the inlet (1) and outlet (2) are located on the same side of the device (i.e. at the top of the device in this illustration). The linear flow control structure in the center of the device forms a single channel within the device. Flow is directed down through the device from the inlet at the top and then loops back to exit the device via the outlet also located at the top of the device.

[0282] Figure 23a A square shaped rectangular device is shown comprising a unit (70) with a single channel (73) created by a control structure (77). The inlet (1) is located at the top of the device and the outlet (2) is located at the bottom. In this arrangement, fluid can flow by gravity and it is optimized to fill flat areas that have less requirement for energy input for pumping.

[0283] Similar to Figure 23a , Figure 23b A square shaped device is shown comprising a unit (70) with a single channel created by a control structure (77). Both the inlet and outlet are located on the same side of the device (i.e. at the top of the device in this illustration). The linear flow control structure forms a single channel (73) within the device. Flow is directed down through the device from the inlet at the top and then loops back to exit the device via the outlet also located at the top of the device.

[0284] Figures 24 to 26 A photobioreactor module arrangement comprising a plurality of individual devices according to the second aspect of the invention is shown. Such a modular array can be used to fill large spaces. By using a plurality of identical devices in a modular fashion, bioreactor maintenance costs can be minimized. It is within the scope of the invention that a photobioreactor module comprises a plurality of individual devices that are not identical to each other.

[0285] Figure 24 A module is shown comprising streamlined devices. These modules can be, for example Figures 10 to 16 any of the devices (20) shown in

[0286] Figure 25 A module is shown comprising linear devices. These modules can be, for example Figures 17 to 19 any of the devices (40) shown in

[0287] Figure 26 is an example of a modular array device comprising a plurality of units (70) designed to fill a square area. In various embodiments, devices according to the invention can be configured to fill a wide variety of different shapes as needed.

[0288] Figure 27a 、 27b , 27c shows a cross-section through an illustration of some embodiments of the application, and is included to help understand other figures presented herein.

[0289] Figure 30 shows a cross-sectional view of a device (80) according to embodiments of the application (cross-section D in Figure 27c . These structures, which can be made of any suitable translucent (or typically transparent) material, are positioned within the pocket to control the passage of liquid media through the device and to provide structural support for the device.

[0290] Figure 28a shows a cross-sectional view of a unit (80) according to embodiments of the application (cross-section B in Figure 27a , having a first film layer (81) and a second film layer (84) bonded together by a glue interface (82).

[0291] Figure 28b shows a cross-sectional view of a unit (80) according to embodiments of the application (cross-section B in Figure 27a , having a first film layer (81) and a second film layer (84) with a structural component (83) therebetween, with the films bonded by a glue interface (82).

[0292] Figure 29a shows a cross-sectional view of a unit (80) according to embodiments of the application (cross-section D in Figure 27c , having a first film layer (81) and a second film layer (84) bonded together by a glue interface (82). The central bond (85) is a control structure creating two fluid conduits.

[0293] Figure 29b shows a cross-sectional view of a unit according to embodiments of the application (cross-section D in Figure 27c , having a first film layer (81) and a second film layer (84) with a structural component (83) therebetween, with the films bonded by a glue interface (82). The central bond (85) is a control structure creating two fluid conduits.

[0294] Figure 30 shows a cross-sectional view of a device (80) according to embodiments of the application (cross-section D in Figure 27c , representing the mixed components of a bonding technique for creating a bond (82) between film layers.

[0295] Figure 31A cross-sectional view of a unit (80) according to an embodiment of the application is shown, Figure 27c with a cross-section D, wherein artificial light sources (87) are embedded inside the bioreactor and specifically inside the control structure (86) located between the first and second membrane layers (indicated by single and dashed hatched lines).

[0296] Figure 32a A cross-sectional view of a unit according to an embodiment of the application is shown, Figure 27b with a cross-section C, wherein the unit is extruded from a single tubular shaped membrane layer (81) glued to itself (82) at one end by a glue interface.

[0297] Figure 32b A cross-sectional view of a unit (80) according to an embodiment of the application is shown, Figure 32a with a cross-section C, the unit having structural components (83) between membranes (81) glued to themselves (82) by a glue interface. Figure 27b

[0298] Figure 33a A cross-sectional view of a unit (80) according to an embodiment of the application is shown, having a first membrane layer (81) and a second membrane layer (84), wherein additional components (89) are located inside the unit formed by the two membrane layers.

[0299] Figure 33b A cross-sectional view of a unit (80) according to an embodiment of the application is shown, having structural components (83) between membranes (81, 84) glued together by a glue interface (82). Figure 33a

[0300] Figure 34 A cross-sectional view of a unit according to an embodiment of the application is shown, having a first membrane layer (3) and a second membrane layer (4), and indicating optional directions of gas permeation through the membrane layers, either outward (5) or inward (6).

[0301] Generating and harvesting biomass

[0302] Figure 36 ​​is an illustration of a suitable process cycle (150) for generating and harvesting biomass using the device of the present invention (on a continuous or batch basis). (A) shows the starting state when the device is installed and empty. (B) shows the initialization phase when the device is filled with a liquid medium containing photosynthetic microorganisms. In this phase, biomass is generated within the device until it reaches the desired biomass density level in the liquid medium, indicated by phase (C). In a more preferred embodiment of the present invention, this system cycle is a continuous system cycle, after phase (C) the liquid medium is continuously circulated in the unit of the system. The biomass in the system is periodically and / or continuously harvested (indicated by phase (D)) and directed to a biomass receptacle or it can be fed into a "new system cycle" and / or a new unit (as indicated by the arrow connecting (B) to (D)). The skilled person will find the optimal timing of biomass extraction to mainly depend on the metabolic and / or growth rate of the microorganisms. The biomass that has been lost from the system at phase (D) can be regenerated by the photosynthetic activity of the microorganisms remaining in the system. This continuous system cycle can optionally be performed in a batch system cycle, wherein the liquid medium is not continuously circulated in the system, but remains static for a period of time (growth phase) before the biomass is mainly harvested from the system, and the final growth phase is restarted by the microorganisms remaining in the system.

[0303] Figure 37 is an illustration of a possible "biofilm-driven" cycle for generating and harvesting biomass using some embodiments of the present invention (on a continuous or batch basis). (A) shows the starting state when the device is installed and empty. (B) shows the initialization phase when the device is filled with a liquid medium and photosynthetic microorganisms. (C) is the biofilm growth phase. The biofilm starts to develop inside the device. Phase (D) indicates biomass generation. The biofilm that has been formed actively performs photosynthesis and thereby generates more biomass in the liquid medium included within the device. At phase (E), the biomass has accumulated within the unit of the device and is ready to be harvested. Phase (F) shows the harvesting of biomass from the device. In this phase, the harvested biomass can be directed to a biomass receptacle for collection or it can be fed into a new system cycle (as indicated by the arrow connecting (F) to (B)). Further cycles can exist between (F), (D) and (E), whereby the biomass that has been lost from the system at phase (F) can be regenerated by the photosynthetic activity of the microorganisms remaining in the device. Thus, (D), (E) and (F) can represent discrete systems within the overall system shown in Figure 37 (D), (E) and (F) can each occur simultaneously, such that continuous harvesting and continuous regeneration of biomass is achieved using such embodiments of the present invention.

[0304] The present invention is further exemplified with reference to the following non-limiting examples.

[0305] Example

[0306] The experimental setup was designed to demonstrate the system according to an embodiment of the application. In particular, the setup demonstrated the oxygen and carbon dioxide gas transfer through the membrane layer of a photobioreactor unit filled with a liquid medium and photosynthetic microorganisms.

[0307] Figure 40 The case study setup is represented in a simplified manner.

[0308] The unit (201) was made of two polysiloxane membrane layers of 100 microns thickness having an oxygen permeation coefficient equal to about 400 Barrer (at 23°C +- 2°C), a carbon dioxide permeation coefficient equal to about 2100 Barrer (at 23°C +- 2°C) and a nitrogen permeation coefficient equal to about 200 (at 23°C +- 2°C).

[0309] The system was filled with a liquid medium containing a culture of Synechocystis sp. The system was air-tight, so that the gas exchange between the liquid medium in the system and the air outside the system could occur solely through the polysiloxane membrane layers of the unit (201).

[0310] The dissolved oxygen concentration level in the liquid medium was expected to stabilize at about the water oxygen saturation level at 30°C +- 2°C, which is about 7.5 mg / l +- 0.3 mg / l.

[0311] The carbon dioxide introduced from the air was expected to cause the pH level to decrease over time.

[0312] The reservoir (202) was designed to be air-tight and housed the sensors (203). The sensors (203) used for this case study were one optical oxygen sensor "InPro 6860i" from Mettler Toledo, one pH sensor "601500" from Extech Instrument, one high resolution dual fiber turbidity sensor "InPro 8200" from Mettler Toledo, two temperature immersion probes PT100 / Class A, 14132821-TF45 from Wika. Two 36W fluorescent tubes (205) provided the main illumination source. A pressure regulating valve (206) was introduced to regulate the expansion of the unit pressure between the unit (201) and the reservoir (202).

[0313] The liquid medium temperature was maintained at about 30°C (+- 2°C), the liquid medium temperature being maintained by a heated secondary water bath surrounding the main reservoir (202).

[0314] The liquid medium was pumped intermittently through the system by a peristaltic pump (104) at 730 ml / min. When fully inflated with liquid medium, the cell (201) is 19 cm long, 9 cm wide and approximately 1.5 cm thick.

[0315] Data relating to the oxygen concentration levels dissolved in the liquid medium were recorded during two trial runs (Runs A and B). As shown in the graphs presented in Figures Figure 41a and Figure 41b respectively, the oxygen concentration levels decreased significantly over the experimental period. This indicates oxygen transfer across the membrane is occurring.

[0316] The rate of change of pH measured in the medium was partially attenuated by the presence of dissolved compounds (naturally contained in the algal medium) which act as pH buffers. An example of a typical buffering compound is phosphate dissolved in the medium which is used to provide the essential metabolic nutrients to the culture. Although a small decrease in pH was observed during the experimental runs, the magnitude of the pH change typically caused by carbon dioxide dissolution in water was neutralised by the action of the buffer. After a significant period of time beyond the time period of Runs A and B, the continued dissolution of carbon dioxide made the pH change visible (data not shown).

[0317] The results of the experimental runs are presented below:

[0318] Run A

[0319]

[0320] Average temperature 28.4°C +- 2°C

[0321] Run B

[0322]

[0323] Average temperature 29.5°C +- 2°C

[0324] While specific embodiments of the application have been disclosed in detail herein, this has been done solely for the purposes of illustration and by way of example. The above-mentioned embodiments are not intended to limit the scope of the claims appended below. The inventors contemplate that various alternative, modified and equivalent forms of the application can be practiced in the scope of the claims appended below.

Claims

1. A photobioreactor apparatus for culturing photosynthetic microorganisms and facilitating gas transfer between an internal fluid and an external atmosphere, comprising: (i) a photobioreactor unit comprising a membrane layer, the membrane layer defining the photobioreactor unit capable of containing a fluid, wherein the membrane layer is translucent or transparent, and wherein at least a portion of the membrane layer is permeable to gas, wherein the permeance of carbon dioxide through the membrane layer is at least 1000 Barrer; and (ii) inlet and outlet ports for enabling circulation of a fluid through the unit.

2. The apparatus of claim 1, wherein (i) the photobioreactor unit is defined by a single sheet of the membrane layer, wherein at least a portion of the membrane layer is bonded to itself; or (ii) the photobioreactor unit is defined by a single sheet of the membrane layer arranged in a tubular shape; or (iii) the photobioreactor unit is defined by the membrane layer and a second non-membrane layer, the two layers arranged such that at least a portion of the membrane layer is directly bonded to at least a portion of the second non-membrane layer to form a defined boundary around the non-bonded portions of the membrane layer and second non-membrane layer.

3. The apparatus of claim 1 or 2, wherein all of the membrane layer is permeable to gas.

4. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to oxygen, and the permeance of oxygen through the membrane layer is at least 100 Barrer.

5. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to oxygen, and the permeance of oxygen through the membrane layer is at least 300 Barrer.

6. The apparatus of claim 5, wherein the permeance of oxygen through the membrane layer is at least 500 Barrer.

7. The apparatus of claim 5, wherein the permeance of oxygen through the membrane layer is at least 820 Barrer.

8. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to carbon dioxide, and the permeance of carbon dioxide through the membrane layer is at least 2000 Barrer.

9. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to carbon dioxide, and the permeance of carbon dioxide through the membrane layer is at least 2500 Barrer.

10. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to carbon dioxide, and the permeance of carbon dioxide through the membrane layer is at least 3000 Barrer.

11. The apparatus of claim 1 or 2, wherein at least a portion of the membrane layer is permeable to carbon dioxide, and the permeance of carbon dioxide through the membrane layer is at least 3820 Barrer.

12. The apparatus of claim 1 or 2, wherein the membrane layer comprises a material selected from one of the following: silicone and polysiloxane.

13. The device of claim 1 or 2, wherein the membrane layer comprises a material selected from the group consisting of: polydimethylsiloxane (PDMS), fluorosilicone, and organosilicone.

14. The device of claim 12, wherein the material comprises polydimethylsiloxane (PDMS) or an elastomer thereof.

15. The device of claim 1 or 2, wherein a photosynthetic microorganism is contained within the unit.

16. The device of claim 15, wherein the photosynthetic microorganism is selected from the group consisting of: Dunaliella, Haematococcus, Chlorella, Scenedesmus, Synechococcus, Synechocystis, Arthrospira, Spirulina, Chlamydomonas, Galdieria, Klebsormidium, Chroococcidiopsis, Phormidium, Lyngbya, Oscillatoria, Cladophora, Microcystis, Nostoc, and Anabaena.

17. The device of claim 15, wherein the photosynthetic microorganism is selected from the group consisting of: Haematococcus pluvialis, Chlorella autotrophica, Chlorella vulgaris, Synechococcus elongatus, Synechococcus marinus, Arthrospira platensis, Arthrospira maxima, and Chlamydomonas reinhardtii.

18. The device of claim 16, wherein the photosynthetic microorganism is selected from Dunaliella.

19. The device of claim 17, wherein the photosynthetic microorganism is selected from Synechococcus.

20. The device of claim 1 or 2, wherein the photobioreactor unit further comprises at least one flow control structure.

21. The device of claim 1 or 2, wherein the photobioreactor unit further comprises at least one biological support.

22. The device of claim 1 or 2, further comprising a supplementary system in fluid communication with the photobioreactor unit.

23. The device of claim 22, wherein the supplementary system comprises at least one from the group consisting of: a conduit; a reservoir; a pump; a valve; a biomass separator; a lighting system; a temperature control system; a sensor; and a computer / CPU controller.

24. The device of claim 1 or 2, further comprising a plurality of photobioreactor units.

25. A photobioreactor system for culturing photosynthetic microorganisms and facilitating gas transfer between an internal fluid and an external atmosphere, comprising: (a) at least one photobioreactor unit comprising a membrane layer defining the photobioreactor unit capable of containing a fluid, wherein the membrane layer is translucent or transparent, and wherein at least a portion of the membrane layer is permeable to gas, wherein the permeability coefficient of carbon dioxide across the membrane layer is at least 1000 Barrer; and an inlet and outlet port for enabling circulation of fluid through the unit; (b) a fluid reservoir in fluid communication with the inlet and outlet port of the at least one photobioreactor unit; and (c) a pump for maintaining fluid circulation throughout the system.

26. The system of claim 25, wherein (i) the at least one photobioreactor unit is defined by a single sheet of the membrane layer, wherein at least a portion of the membrane layer is bonded to itself; or (ii) the at least one photobioreactor unit is defined by a single sheet of the membrane layer arranged in a tubular shape; or (iii) the at least one photobioreactor unit is defined by a membrane layer and a second non-membrane layer, the two layers arranged such that at least a portion of the membrane layer is directly bonded to at least a portion of the second non-membrane layer to form a defined boundary around the non-bonded portions of the membrane layer and second non-membrane layer.

27. The system of claim 25 or 26, wherein at least a portion of the membrane layer is permeable to oxygen and the membrane layer has a permeability coefficient for oxygen of at least 100 Barrer.

28. The system of claim 25 or 26, wherein at least a portion of the membrane layer is permeable to oxygen and the membrane layer has a permeability coefficient for oxygen of at least 300 Barrer.

29. The system of claim 25 or 26, wherein at least a portion of the membrane layer is permeable to oxygen and the membrane layer has a permeability coefficient for oxygen of at least 500 Barrer.

30. The system of claim 25 or 26, wherein at least a portion of the membrane layer is permeable to oxygen and the membrane layer has a permeability coefficient for oxygen of at least 820 Barrer.

31. The system of claim 25 or 26, wherein the membrane layer comprises a material selected from one of the following: silicone and polysiloxane.

32. The system of claim 25 or 26, wherein the membrane layer comprises a material selected from one of the following: polydimethylsiloxane (PDMS), fluorosilicone, and organosilicone.

33. The system of claim 25 or 26, wherein the membrane layer has a permeability coefficient for carbon dioxide of at least 2000 Barrer.

34. The system of claim 25 or 26, wherein the membrane layer has a permeability coefficient for carbon dioxide of at least 3000 Barrer.

35. The system of claim 25 or 26, wherein the membrane layer has a permeability coefficient for carbon dioxide of at least 3820 Barrer.

36. The system of claim 25 or 26, wherein at least one photosynthetic microorganism is included within the unit.

37. The system of claim 36, wherein the photosynthetic microorganism is selected from one of the following: Dunaliella salina, Haematococcus, Chlorella, Scenedesmus, Synechococcus, Synechocystis, Arthrospira, Spirulina, Chlamydomonas, Galdieria, Chroomonas, Porphyridium, Dactylococcopsis, Oscillatoria, Nostoc, Gleocapsa, Microcystis, Nephrocytium, and Anabaena.

38. The system of claim 36, wherein the photosynthetic microorganism is selected from one of the following: Haematococcus pluvialis, Chlorella autotrophica, Chlorella vulgaris, Synechococcus elongatus, Synechococcus marinus, Arthrospira platensis, Arthrospira maxima, and Chlamydomonas reinhardtii.

39. The system of claim 37, wherein the photosynthetic microorganism is selected from the group consisting of Dunaliella salina.

40. The system of claim 38, wherein the photosynthetic microorganism is selected from the group consisting of Synechococcus.

41. The system of claim 25 or 26, wherein the system further comprises at least one of the group consisting of: a conduit; a valve; a biomass separator; an illumination system; a temperature control system; a sensor; and a computer / CPU controller.

42. The system of claim 25 or 26, wherein the system further comprises: (d) a biomass collector.

43. A method for producing biomass, the method comprising: culturing photosynthetic microorganisms within the device of any one of claims 1 to 24, and harvesting the biomass from the device.

44. A method for producing biomass, the method comprising: culturing photosynthetic microorganisms within the system of any one of claims 25 to 42, and harvesting the biomass from the system.

45. A method for treating wastewater, the method comprising: culturing photosynthetic microorganisms within the device of any one of claims 1 to 24, passing wastewater through the device, whereby the photosynthetic microorganisms within the device remove or remediate toxins from the wastewater.

46. A method for removing atmospheric pollutants, the method comprising: culturing photosynthetic microorganisms within the device of any one of claims 1 to 24, exposing the device to an atmosphere comprising the pollutant, whereby the photosynthetic microorganisms within the device remove or remediate the pollutant from the atmosphere.

47. A photobioreactor device comprising: (i) a photobioreactor unit for culturing photosynthetic microorganisms and facilitating gas transfer between an internal fluid and an external atmosphere, comprising a membrane layer, the membrane layer defining the photobioreactor unit capable of containing a fluid, wherein the membrane layer is translucent or transparent, and wherein at least a portion of the membrane layer comprises a polysiloxane; and (ii) inlet and outlet ports for enabling circulation of a fluid through the unit.

48. The device of claim 47, wherein the polysiloxane comprises polydimethylsiloxane (PDMS) or an elastomer thereof.

49. The device of claim 47 or 48, wherein (i) the photobioreactor unit is defined by a single sheet of the membrane layer, wherein at least a portion of the membrane layer is bonded to itself; or (ii) the photobioreactor unit is defined by a single sheet of the membrane layer arranged in a tubular shape; or (iii) the photobioreactor unit is defined by the membrane layer and a second, non-membrane layer, the two layers arranged such that at least a portion of the membrane layer is directly bonded to at least a portion of the second, non-membrane layer to form a defined boundary around the non-bonded portions of the membrane layer and second, non-membrane layer.

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