Photobioreactor including means of translational movement, microalgal biomass production assembly including such a photobioreactor

Abstract

The present invention relates to a photobioreactor (3) for the production of biomass in a closed system, comprising: - a biomass container comprising a first flat wall (30) and a second flat wall (31), the two flat walls (30, 31) being parallel, - a base (32) extending perpendicularly from an edge (300) of the first flat wall (30) to an edge (310) of the second flat wall (31), the two flat walls (30, 31) and the base (32) delimiting between them a space for the development of biomass, - means of movement (5) mounted on the base (32), fixed with the biomass container in translation along a sliding direction (B), and configured to guide a translational movement of the biomass container along a track (23) of a support structure (2) carrying the photobioreactor, parallel to the sliding direction (B). Figure for the abbreviation: Figure 2

Description

Title of the invention: Photobioreactor comprising translational displacement means, assembly for producing microalgal biomass comprising such a photobioreactor GENERAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of industrial production of microalgal biomass.

[0002] The cultivation of microalgal biomass finds in particular a first application for the treatment and purification of wastewater by "phyco-remediation". Microalgae are capable of eliminating organic or inorganic polluting compounds (metals, hydrocarbons, pesticides, etc.) present for example in industrial effluents, such as wastewater leaving a factory. The cultivation of microalgal biomass finds a second application for obtaining molecules of interest, such as for example biofuels or bioproducts useful in the sectors of food, human and animal medicine, cosmetics, construction, agriculture, etc. STATE OF THE ART

[0003] As is known, certain species of algae can be cultivated and used for the decontamination or remediation of effluents such as wastewater, waste or industrial gases. The term "phyco-remediation" refers to the decontamination of effluents using microalgal biomass. Microalgae are capable of capturing polluting agents and absorbing excess harmful products such as carbon dioxide, carbon monoxide, nitrates, nitrites, urea, ammonium and phosphates mainly.

[0004] There are high-yield open-system microalgae culture ponds, called HRAP systems or "High Rate Algal Pond" in common English terminology. However, in such open systems, the microalgae culture medium is in contact with the external environment and it is difficult to control the culture medium (in terms of temperature, pressure, nutrient content, etc.). The open nature of the ponds increases the risk of contamination by external biological agents, or even of atmospheric cross-contamination by other microalgae species.

[0005] To overcome these limitations of open systems, closed system photobioreactors have been designed. An aqueous medium rich in minerals (such as salt), gases (such as carbon dioxide) and nutrients is circulated in a closed loop in a series of photobioreactors. The production of microalgal biomass at The interior of the photobioreactors is controlled by modifying the supply of nutrients, carbon dioxide and minerals, and by controlling the physicochemical parameters of the aqueous medium (notably temperature, pressure, pH).

[0006] A first known closed photobioreactor is of vertical tubular shape. This type of photobioreactor has the advantage of occupying a small floor space.

[0007] However, vertical tubular photobioreactors pose numerous operational problems. In particular, fouling phenomena ("bio-fouling") are observed on the internal surfaces of the photobioreactor. In addition, the maintenance of vertical tubular reactors is particularly complex, especially in the case of industrial installations.

[0008] Furthermore, such vertical photobioreactors generally have a fairly low light absorption rate, even if this absorption rate can be increased by using narrow diameters, and / or by using two tubes of different diameters and by arranging the culture in the crown between these two tubes arranged one inside the other.

[0009] Tubular horizontal photobioreactors have also been proposed. However, the volume of crops that can be grown per square meter of land area is low. Thus, for a given land area, the biomass production capacity is low. In addition, the use of horizontal photobioreactors does not entirely solve the aforementioned problems related to biofouling. Finally, the removal of oxygen produced by the crop present in horizontal photobioreactors requires complex degassing systems, and reduces the performance of the photobioreactors.

[0010] There are also parallelepipedal-shaped photobioreactors of the “flat photobioreactor” type. The culture medium is typically defined between two transparent parallel side walls, for example rectangular in shape. A first advantage of flat photobioreactors is that they allow good illumination of the entire internal volume of the biomass culture container, from the outside. The rate of absorption of light by the biomass is therefore more satisfactory.

[0011] Additional advantages of flat photobioreactors are that flat photobioreactors allow good removal of dissolved oxygen resulting from photosynthesis, and are a better solution for the aeration system needed to avoid sedimentation. In addition, these photobioreactors promote increased crop multiplication frequency in the illuminated area, facilitate the injection of carbon dioxide, and are easier to handle (depending on their size) by maintenance personnel.

[0012] In the field of architecture and hydraulics of biomass production systems existing, document US 2010 / 028976 A1 belonging to the state of the art describes a “serpentine” installation comprising flat photobioreactors arranged in series, one after the other.

[0013] In this document, the photobioreactors are juxtaposed horizontally in rows, along their edge. The rectangular side walls of the photobioreactors in the same row are aligned in the same plane. A single culture medium inlet line supplies culture medium to all the photobioreactors in the same row. Each photobioreactor is fixed; removable covers allow access to the interior volume of the photobioreactors.

[0014] However, in this document, the serpentine alignment for photobioreactors is not optimal from the point of view of the footprint. To add photobioreactors and increase the production capacity, it is only possible to enlarge the occupied floor area; it is not possible to add photobioreactors vertically in the height direction. In addition, the space present on the floor between two consecutive parallel rows is not used.

[0015] Furthermore, the disassembly and extraction of a given photobioreactor (for example for cleaning, or for replacement, or in the event of a breakdown) interrupts the proper functioning of an entire row of photobioreactors. Biomass production is therefore not very robust with respect to possible breakdown events.

[0016] Finally, it is noted that cleaning the installation presented in this document is not easy; the photobioreactors include separators in their internal space, which can increase the fouling of these photobioreactors and make their cleaning more difficult.

[0017] The flat photobioreactors described in this document are therefore not easily industrializable on a production site.

[0018] Document US 2017 / 267957 A1 proposes a biomass production facility based on the principle of semi-continuous cultivation. It describes parallelepipedal biomass storage containers, stackable vertically to form a multi-stage photobioreactor. Several independent cultivation environments are created, and the biomass grows in several independent phases. Such a multi-stage arrangement can be advantageous from the point of view of land use.

[0019] However, this document does not propose a modular vertical stack; the number of photobioreactor stages is determined in advance. It is therefore also not possible here to add photobioreactors vertically in the height direction, to increase the production capacity.

[0020] Furthermore, the biomass storage containers of a given photobioreactor are not not easily separable. This document therefore does not describe a solution for extracting a photobioreactor without affecting the productivity of the installation. Finally, a photobioreactor support structure is not described in this document. GENERAL DESCRIPTION OF THE INVENTION

[0021] In view of the above, an objective of the invention is to provide a photobioreactor for a microalgal biomass production site, for example for phyco-remediation, which can be easily accessible and isolated from other neighboring photobioreactors in the same row. Extraction from a photobioreactor must be rapid, and must not require an interruption in the operation of the installation. It is thus desired to limit the impact of maintenance and cleaning of a photobioreactor (in particular the defouling of the walls of the photobioreactor) on the productivity of the installation.

[0022] Another objective is to provide a photobioreactor whose footprint (surface area occupied on the ground) is limited, so as to limit the footprint and to optimize the occupation of space on a microalgal biomass production site.

[0023] Another objective is to obtain a photobioreactor support structure, which allows the size of the photobioreactor group to be easily extended or reduced (preferably in all directions, both vertically and horizontally).

[0024] We thus seek to improve the modularity of the industrial installation, by easily adding or removing height capacity, by stacking several supports.

[0025] The mechanical design of the photobioreactor support structure must remain simple, and this support structure must be easy to manufacture and transport.

[0026] A secondary objective is to enable the simultaneous handling and transport of several such support structures, in a grouped manner. Preferably, the biomass production unit must be able to be put into service immediately after installation, in "turnkey" mode.

[0027] To meet these needs, according to a first aspect, the invention relates to a photobioreactor for the production of biomass in a closed system, the photobioreactor comprising: a biomass container comprising a first flat wall having a first edge and a second flat wall having a second edge juxtaposed with the first edge, the two flat walls being parallel, a base extending perpendicularly to the two flat walls from the first edge to the second edge, the two flat walls and the base delimiting between them a biomass development space, and means of movement integral with the biomass container in translation along a sliding direction, the movement means being configured to guide a translational movement of the biomass container along a track of a support structure carrying the photobioreactor, parallel to the sliding direction, the movement means being mounted on the base.

[0028] The photobioreactor according to the first aspect of the invention makes it possible to reinforce the modularity and efficiency of the installation. In particular, an advantage of such a photobioreactor is to be able to very easily increase or reduce the size of a group of photobioreactors, by stacking or unstacking the photobioreactors (along a stacking direction perpendicular to the sliding direction). The footprint (surface area occupied on the ground) of the reactors is thus limited.

[0029] An additional advantage of such a photobioreactor is the ease of maintenance and cleaning. Any photobioreactor can be easily extracted from a support structure using the movement means integrated into the photobioreactor. Thanks to the movement means, the photobioreactors are preferably extractable independently of each other.

[0030] Optional and non-limiting features of the photobioreactor according to the first aspect of the invention are the following, taken alone or in any of the possible combinations of features:

[0031] - the moving means are mounted on the base at one face of the base opposite the first edge and opposite the second edge.

[0032] - the photobioreactor comprises a rail mounted on the base, the rail extending longitudinally finally along the sliding direction.

[0033] - the moving means are arranged in an interior space of the rail.

[0034] - the moving means comprise at least one wheel, the de placement preferably comprising at least two wheels.

[0035] - the photobioreactor comprises a cover closing the development space of biomass, the cover extending perpendicular to the two flat walls opposite the base.

[0036] - said cover is removable from the biomass container.

[0037] - the photobioreactor comprises at least one wall of thickness connecting the first flat wall and the second flat wall.

[0038] - the photobioreactor comprises a gripping means fixed on the thickness wall.

[0039] - the base is formed from thermoplastic polymer, preferably polychloride vinyl called PVC.

[0040] - the first flat wall and / or the second flat wall are formed from thermopolymer moplastic, preferably polymethyl methacrylate known as PMMA.

[0041] According to a second aspect, the invention relates to a photobioreactor support structure, the support structure being configured to receive in a manner removable a plurality of photobioreactors for biomass production as defined above, the support structure extending longitudinally along a stacking direction, the support structure comprising: at least two parallel frames, the frames being axially spaced along the stacking direction and axially defining between them a photobioreactor receiving space, and a receiving face secured to the frames and extending between the frames along the stacking direction, configured to support a plurality of photobioreactors, the receiving face comprising a plurality of tracks, each track extending parallel to a sliding direction perpendicular to the stacking direction, and being configured to cooperate with means for moving a photobioreactor so as to guide a translation of said photobioreactor parallel to the sliding direction relative to the support structure.

[0042] Optional and non-limiting features of the support structure according to the second aspect of the invention are the following, taken alone or in any of the possible combinations of features:

[0043] - the support structure has six parallelepiped faces, the six parallel faces piped defining a parallelepiped internal volume.

[0044] - at least one photobioreactor is movable parallel to the sliding direction between a first position entirely included in the parallelepiped internal volume and a second position partially outside said volume.

[0045] - the support structure comprises at least one rail fixed to the receiving face, and a track of the receiving face extends along an interior space of said rail parallel to the sliding direction.

[0046] - the number of tracks is greater than or equal to 5 and is less than or equal to 100, of preferably greater than or equal to 20 and less than or equal to 40.

[0047] - the support structure comprises a closing surface fixed on the frames and arranged opposite the receiving surface.

[0048] - said closing surface comprises at least one configured cover guide to guide in translation a cover of a photobioreactor received in the photobioreactor reception space.

[0049] - the support structure further comprises at least one intermediate frame extending in a plane parallel to each of the two frames, the intermediate frame being arranged between the two frames.

[0050] - the support structure further comprises a suspension attachment configured for fixing a crane cable, so as to allow lifting of the supporting structure.

[0051] - at least one frame is rectangular in shape and comprises two opposite corners.

[0052] - said frame comprises a brace connecting the two corners.

[0053] According to a third aspect, the invention relates to a biomass production assembly comprising: a photobioreactor support structure as defined above, the support structure comprising a plurality of tracks, and a plurality of photobioreactors as defined above, the photobioreactors being placed along the stacking direction of the support structure, each photobioreactor being in contact with a track of the support structure at the level of the means for moving said photobioreactor.

[0054] Optional and non-limiting features of the biomass production assembly according to the third aspect of the invention are the following, taken alone or in any of the possible combinations of features:

[0055] - the number of photobioreactors is greater than or equal to 5 and is less than or equal to 100, preferably greater than or equal to 20 and less than or equal to 40.

[0056] - the assembly further comprises at least one luminous element placed along the stacking direction between two photobioreactors, the light element being configured to provide light radiation to both said photobioreactors.

[0057] - the support structure comprises a frame attachment, and the assembly comprises in in addition to an additional support structure attached to the support structure via the frame clip. GENERAL DESCRIPTION OF THE FIGURES

[0058] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended figures, among which:

[0059] [Fig-1] [Fig. 1] is a perspective view of a biomass production assembly according to an exemplary embodiment, comprising in particular a plurality of photobioreactors mounted in a support superstructure.

[0060] [Fig.2] [Fig.2] is a schematic perspective view of a photobioreactor of the biomass production assembly of [Fig.1], juxtaposed with a light panel of the biomass production assembly.

[0061] [Fig.3] [Fig.3] is a close-up view from below of a wheel support profile, mounted on a base of the photobioreactor of [Fig.2].

[0062] [Fig.4] [Fig.4] is a schematic cross-sectional view of a lower part of the photobioreactor of [Fig.2], according to a section plane perpendicular to a direction of translational movement of the photobioreactor.

[0063] [Fig.5] [Fig.5] is a perspective view from above of a superstructure of photobioreactor support of the biomass production assembly of [Fig.l].

[0064] [Fig.6] [Fig.6] is a schematic view of two support superstructures of photobioreactors fixed together, a plurality of photobioreactors being mounted in the two support superstructures.

[0065] [Fig.7a][Fig.7b][Fig.7c] Figures 7a, 7b and 7c are close-up views respectively of a clip between two end frames of the support superstructure of [Fig.6], of a clip between two intermediate frames of the support superstructure of [Fig.6], and of a crane cable clip provided on an upper face of the support superstructure of [Fig.6].

[0066] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0067] Throughout the attached figures and throughout the description below, similar elements bear identical alphanumeric references.

[0068] General architecture of a biomass production unit in a closed system

[0069] [Fig.l] shows a biomass production unit 1 according to an example. The biomass production unit 1 is for example installed in a phyco-remediation effluent treatment site.

[0070] The microalgal biomass is obtained from monoclonal or polyclonal cultures (as the case may be) of preferably unicellular species, colonial or not.

[0071] For example, biomass is used to remove excess substances, such as nitrogen, from industrial effluents. The biomass production assembly 1 can also be used to manufacture bioproducts of interest, such as biofuels, on an industrial scale.

[0072] The biomass production assembly 1 comprises a support superstructure 2. The superstructure 2 extends longitudinally in a stacking direction A. When the superstructure 2 is in place on the ground, the stacking direction A is typically oriented horizontally, parallel to the ground.

[0073] The biomass production assembly 1 further comprises a plurality of photobioreactors 3 removably mounted inside the superstructure 2. The lateral faces 30, 31 of the photobioreactors 3 are parallel two by two. The photobioreactors 3 are preferably stacked horizontally “in a sandwich” along the stacking direction A. In this example, the superstructure 2 supports 30 photobioreactors. The structure of a photobioreactor 3 will be described in detail below.

[0074] The biomass production assembly 1 may also comprise a hydraulic and / or pneumatic system (not illustrated in [Fig.l]), which can be removably fixed to the superstructure 2. Such a hydraulic and / or pneumatic system may be placed in fluid communication with water inlets and / or water outlets and / or air inlets and / or air outlets of the photobioreactors 3.

[0075] Such a hydraulic and / or pneumatic system is for example placed opposite a face of the superstructure 2 opposite the face by which the photobioreactors 3 can be extracted in translation. Mobile photobioreactor in translation

[0076] [Fig. 2] is a close-up perspective view of a photobioreactor 3 for producing biomass in a closed system. The photobioreactor 3 can be integrated into a biomass production assembly 1 as shown in [Fig. 1].

[0077] The photobioreactor 3 of [Fig. 2] has a generally parallelepiped shape. It is referred to as a “flat photobioreactor” because the lateral thickness E of the photobioreactor 3, along the stacking direction A of the photobioreactors (not shown), is small compared to the length L1 of the side walls 30 and 31 of the photobioreactor 3, and is also small compared to the height L2 of the side walls 30 and 31 of the photobioreactor 3.

[0078] • Biomass development container

[0079] The side walls 30 and 31 of the photobioreactor 3 are planar. The side walls 30 and 31 preferably extend in respective planes parallel to the sliding direction B of the photobioreactor 3.

[0080] Preferably, the side walls 30 and 31 are rectangular in shape. The edges of the side walls 30 and 31 are preferably rectilinear and aligned along the stacking direction A. In particular, the lower edge 300 of the side wall 30 is aligned with the lower edge 310 of the side wall 31. Thus, the photobioreactor 3 retains a compact shape and can easily be stacked with other photobioreactors along the stacking direction A.

[0081] Preferably, the hollow space of the photobioreactor delimited axially by the side walls 30 and 31 comprises at least one wall separator. A first end of the wall separator is arranged against the side wall 30 and a second end of the wall separator is arranged against the side wall 31. An advantage is to avoid deformation of the side walls 30 and 31, in particular at the center of these walls. Preferably, the wall separator(s) extend perpendicular to the direction B.

[0082] The axial space between the side walls 30 and 31 is closed on the sides by two walls of thickness 36 and 37. The walls of thickness 36 and 37 are both preferably rectangular in shape, and perpendicular to the sliding direction B.

[0083] When the photobioreactor 3 is empty and not filled with culture medium, the side walls 30 and 31 and the thickness walls 36 and 37 delimit a hollow space of parallelepiped shape. The hollow space thus defined constitutes a biomass development space. The biomass development space is provided to accommodate microalgae inside the photobioreactor 3, and to allow them to develop.

[0084] The side walls 30 and 31 are formed from transparent material, so as to allow light to enter the biomass development space from the outside. A majority material of the side walls 30 and 31 is preferably a thermoplastic polymer. In the present example, the side walls 30 and 31 are formed from polymethyl methacrylate, known as PMMA.

[0085] A majority material of the walls of thickness 36 and 37 is preferably also a thermoplastic polymer, such as PMMA.

[0086] The internal thickness E of the photobioreactor 3, delimited between the internal faces of the two side walls 30 and 31 along the stacking direction A, is preferably between 1 and 10 centimeters depending on the species to be cultivated and the type of water to be treated. The footprint of the photobioreactor 3 is thus moderate.

[0087] The length L1 of the biomass container between the inner sides of the walls of thickness 36 and 37, parallel to the sliding direction B, is preferably between 0.50 meters and 2.5 meters.

[0088] Finally, the height L2 of the biomass container between the respective inner sides of the base 32 (described below) and the cover 34 (described below) is preferably between 0.50 meters and 2.5 meters.

[0089] Advantageously, at least one of the two walls of thickness 36 and 37 comprises a means for gripping the biomass container. As will be seen below, the biomass container is mounted to move in translation along the sliding direction B; the gripping means allows an operator to slide the biomass container.

[0090] Here, a handle 360 ​​is fixed to the wall of thickness 36 and projects from the wall of thickness 36. The handle 360 ​​acts as a gripping means. The handle 360 ​​is for example formed from metal, here from stainless steel.

[0091] The biomass development space provided inside the side walls 30 and 31 and the thickness walls 36 and 37 is in fluid communication with the outside, and the water supply (via the liquid inlet line 70 and the liquid outlet line 72) and the air supply (via the air inlet mouth 74 and the air outlet mouth 76) are controlled.

[0092] The liquid inlet line 70 here comprises a pipe, a first end of which projects from the wall of thickness 36, and a second end of which opens into the interior of the biomass development space. The first end of the liquid inlet line is preferably positioned on the upper side, in the vicinity of the cover 34.

[0093] The liquid outlet line 72 is preferably arranged opposite the liquid inlet line 70, in the vicinity of the base 32. A first end of the liquid outlet line 72 projects from the wall of thickness 36, and a second end opens into the biomass development space.

[0094] These two liquid lines make it possible in particular to control the water supply.

[0095] The air outlet 74 is here a simple air vent, arranged on the upper side, for example between the liquid inlet line 70 and the cover 34.

[0096] The air inlet 76 is preferably arranged in the vicinity of the base 32. A first end of the air inlet 76 projects from the wall of thickness 36, and a second end opens into the interior of the biomass development space.

[0097] When several photobioreactors 3 are aligned inside the same support superstructure 2, the ends of the liquid inlet lines 70, the liquid outlet lines 72, and the air inlets 76 can be aligned on the same plane. This plane is preferably located on a face of the superstructure 2 opposite the face by which the photobioreactors 3 can be extracted by translation.

[0098] An advantage is that it is possible to easily connect and disconnect a hydraulic and / or pneumatic system, comprising water and / or air recirculation lines laterally offset from the photobioreactors. It is then sufficient to move the photobioreactors closer to or further away from the hydraulic and / or pneumatic system, by translation. Such a hydraulic and / or pneumatic system may also comprise one or more control probe(s).

[0099] Preferably, each liquid inlet and outlet and each aforementioned air inlet comprises its own individual valve, in order to selectively control the supply of water and air into the culture medium of each of the photobioreactors 3.

[0100] Furthermore, each row of photobioreactors 3 (such as the row shown in [Fig.l]) is preferably associated with at least one water recirculation pump and / or one gas recirculation pump and / or one culture medium recirculation pump. Said pumps can be placed at the head of the row of photobioreactors.

[0101] • Lower base

[0102] The side walls 30 and 31 are closed on the lower side by a base 32 and on the upper side by a cover 34.

[0103] The meanings “lower” and “upper” are understood according to the orientation illustrated in [Fig.2] for the photobioreactor 3, corresponding to the usual vertical orientation of a photobioreactor placed in its support superstructure.

[0104] The base 32 has a parallelepiped shape and extends longitudinally along the sliding direction B of the photobioreactor 3. The base 32 has a lower base face 320, an upper base face 321 and two lateral base faces 322. The upper base face 321 extends perpendicular to the two lateral walls 30 and 31. The upper base face 321 is in contact with the lower edge 300 of the lateral wall 30 and with the lower edge 310 of the lateral wall 31.

[0105] The base 32 supports the weight of the side walls 30 and 31 and the thickness walls 36 and 37. A material of the base 32 is preferably a thermoplastic polymer. In the present example, the base 32 is formed from polyvinyl chloride, known as PVC.

[0106] The base 32 preferably protrudes on both sides relative to the side walls 30 and 31, and also preferably protrudes on both sides relative to the thickness walls 36 and 37.

[0107] • Means of translational movement of the photobioreactor

[0108] To allow selective extraction compared to the other photobioreactors, the photobioreactor 3 comprises movement means 5 at its base 32.

[0109] The biomass container is therefore movable in translation along the sliding direction B, via the displacement means 5.

[0110] Thus, when several photobioreactors 3 are aligned (for example “in a sandwich”) along the stacking direction A, it is possible to move a given photobioreactor 3 parallel to the sliding direction B to extract and isolate this photobioreactor from the other photobioreactors.

[0111] Such selective extraction of a photobioreactor is particularly advantageous for replacing a part of the photobioreactor or the entire photobioreactor, for carrying out a maintenance operation, for cleaning the photobioreactor, etc.

[0112] The displacement means 5 are integral with the photobioreactor 3 (in particular integral with the base 32) in translation along the sliding direction B. Preferably, the displacement means 5 have a shape complementary to a shape of a track 23 of the support superstructure 2. The displacement means 5 can slide along the track 23.

[0113] The displacement means 5 are preferably fixedly mounted on the base 32, preferably on the lower face of the base 320.

[0114] Alternatively and / or in combination, movement means could be provided on at least one of the lateral faces of base 322.

[0115] Very advantageously, the movement means 5 comprise at least one wheel. The wheel is oriented parallel to the sliding direction B. In the present example, the movement means 5 comprise two pairs of wheels. A first pair of wheels is arranged on a front side of the photobioreactor 3 (side close to the handle 360) and a second pair of wheels is arranged on a rear side of the photobioreactor 3 (side far from the handle 360). Within each pair of wheels, the wheels are aligned one behind the other in the sliding direction B.

[0116] For mounting the wheels on the photobioreactor, the base 32 preferably comprises a wheel support element 50, attached to the base 32. The support element 50 is preferably fixedly mounted on the base 32.

[0117] The support element 50 is visible in [Fig. 3] in a close-up view from below. Here, the support element 50 has a hollow profile shape and extends along the sliding direction B. Also shown in [Fig. 4] is a cross-sectional view of the support element 50, passing through the wheel housing 52 receiving the displacement means 5.

[0118] An upper portion of the support element 50, on the side directed towards the side walls 30 and 31, here has a U-shape in the cross-sectional plane. The upper portion of the support element 50 comprises two lateral flanks 54. The lateral flanks 54 are preferably pressed against the base lateral faces 322.

[0119] The two lateral flanks 54 are connected on the lower side by a support bottom 540. The support bottom 540 preferably extends perpendicular to the lateral flanks 54 and parallel to the ground, when the photobioreactor 3 is in place.

[0120] The support base 540 is pressed against the lower face of the base 320. The base 32 is therefore received in the transverse space provided between the lateral flanks 54. As can be seen in [Fig. 3], a length of the support element 50 parallel to the sliding direction B is less than the length L1 of the lower face of the base 320.

[0121] The support element 50 further comprises, under its upper part comprising the U-shaped lateral flanks 54, a lower part provided to receive the displacement means 5.

[0122] Preferably, the lower part of the support element 50 has a rail shape 58. The rail 58 is preferably profiled. The rail 58 extends along the sliding direction B and projects from the support bottom 540, on the side opposite the lateral flanks 54. In the present example, the width of the rail 58 is less than the width between the lateral flanks 54 perpendicular to the sliding direction B. The rail 58 here has hooks oriented inwards and downwards.

[0123] Preferably, the transverse space provided in the rail 58 (here between the hooks) comprises a wheel housing 52 in which the wheels are arranged. The wheel housing 52 here has a parallelepiped shape. A hollow space is provided in the wheel housing 52 at a hollowed-out lower face 520 of the wheel housing 52. The wheels are received in this hollow space. Thus, the wheels are protected laterally against impacts.

[0124] Here, two wheels are arranged one in front of the other parallel to the sliding direction B, inside the wheel housing 52.

[0125] Preferably, the photobioreactor 3 comprises at least two support elements 50 each comprising wheels, placed respectively on the front side and the rear side of the base 32. When the photobioreactor 3 is in place in the support superstructure 2, the lower part 522 of the wheels is in contact with a movement track 23, so as to be able to roll along the travel track 23, as will be seen below.

[0126] In the present example, the photobioreactor 3 comprises two identical support elements 50, conforming to the structure shown in Figures 3 and 4.

[0127] • Top cover

[0128] Returning to [Fig.2], to close the biomass development space on the upper side, the photobioreactor 3 preferably comprises a cover 34. The cover 34 extends perpendicular to the two side walls 30 and 31, opposite the base 32, and connects the two side walls 30 and 31.

[0129] The cover 34 extends over the entire length L1 between the two walls of thickness 36 and 37. Preferably, the cover 34 protrudes from the two walls of thickness 36 and 37.

[0130] Preferably, the cover 34 is removable from the biomass container. One advantage is that it allows easy access to the interior of the biomass development space.

[0131] For example, the cover 34 may be removed to harvest the microalgal biomass. The cover 34 may also be removed before cleaning the interior of the side walls 30 and 31 and / or the thickness walls 36 and 37, or during any other operation requiring access to the interior of the biomass growth space. The photobioreactor 3 is typically extracted from the superstructure 2 before removing the cover 34.

[0132] • Light panel

[0133] [Fig.2] also shows a light panel 6 juxtaposed with the photobioreactor 3 in the stacking direction A (not shown).

[0134] The function of the light panel 6 is to provide artificial lighting intended to reach the biomass development space defined inside the photobioreactor 3, between the side walls 30 and 31. The artificial lighting provided can be provided as a replacement or in addition to natural sunlight, depending on the time of day and the geographical area.

[0135] The panel 6 is preferably parallelepipedal. The panel 6 preferably has a generally flat shape, that is to say that the thickness E' between the outer lateral faces 60 and 61 of the panel 6 (along the stacking direction A) is small compared to the other dimensions of the panel 6. In the present example, the thickness E' is preferably between 1 and 10 centimeters.

[0136] Preferably, the lateral faces 60 and 61 of the panel 6 extend parallel to the lateral faces 30 and 31 of the photobioreactor 3 to which the panel 6 is juxtaposed. Advantageously, a surface area of ​​the lateral faces 60 and 61 is greater than or equal to a surface area of ​​the lateral walls 30 and 31. Thus, the panel 6 covers a major part of the surface area or the entire surface area of ​​the lateral walls 30 and 31 of the photobioreactor. 3, so as to provide good illumination throughout the biomass growth space inside the photobioreactor 3.

[0137] For panel 6 illustrated in [Fig.2]:

[0138] - A length of the panel 6, parallel to the sliding direction B of the photobioreactor 3, is substantially equal to the length L1 of the walls of the photobioreactor 3; - A height L' of the panel 6, perpendicular to the stacking direction A and perpendicular to the sliding direction B, is preferably greater than or equal to the height L2 of the photobioreactor 3. The height of the panel 6 is preferably between 0.50 meters and 2.5 meters.

[0139] The panel 6 preferably comprises, as artificial light sources, light-emitting diodes commonly called LEDs. The LEDs are preferably distributed regularly on the surface of the side faces 60 and 61 of the panel 6. The light intensity of the artificial light sources is preferably remotely controllable, to modulate the lighting and the electrical energy consumption of the panel 6 according to the illumination needs for the microalgal biomass.

[0140] Preferably, if several photobioreactors 3 are stacked along the stacking direction A, a light panel 6 is inserted in each pair of consecutive photobioreactors 3. The panel 6 is preferably capable of emitting light on both of its faces; a single panel 6 thus provides light to two photobioreactors.

[0141] The photobioreactor 3 as described above has a simple mechanical design. The photobioreactor 3 can operate autonomously by being connected directly to a recirculation and aeration system.

[0142] In addition, the photobioreactor 3 can be connected in a modular manner with other photobioreactors of similar design, so as to form a microalgal biomass production assembly.

[0143] The photobioreactor 3 is easily stackable with other photobioreactors, both horizontally (along the stacking direction A) and vertically. Photobioreactor support superstructure

[0144] [Fig. 5] illustrates a superstructure 2 configured to receive and mechanically support a plurality of photobioreactors 3. The photobioreactors 3 are preferably received removably; they are not attached to the support frames of the superstructure 2. In this figure, the superstructure 2 is shown separately from the photobioreactors 3.

[0145] Preferably, the number of photobioreactors that can be received in the superstructure 2 is greater than or equal to 5 and is less than or equal to 100, preferably greater than or equal to 20 and less than or equal to 40. Here, superstructure 2 receives 30 photobioreactors.

[0146] The superstructure 2 is preferably placed directly horizontally on a floor, for example in an industrial site.

[0147] • Support frames

[0148] Preferably, the superstructure 2 has a generally parallelepiped shape, and extends along the stacking direction A. The outer faces of the superstructure 2 are defined by two end frames 20, placed at the two ends along the stacking direction A.

[0149] The two end frames 20 extend in planes perpendicular to the stacking direction A. The two end frames 20 thus define between them a parallelepiped internal volume, forming a photobioreactor reception space.

[0150] For an end frame 20 according to the present example:

[0151] - A width DI of the end frame 20, along the sliding direction B, is preferably between 0.50 meters and 2.5 meters; - A height D2 of the end frame 20, perpendicular to the stacking direction A and to the sliding direction B, is preferably between 0.50 meters and 2.5 meters.

[0152] The end frames 20 are preferably made of a metal material, or a plastic material. In the present example, each end frame 20 is of a hollow rectangular shape.

[0153] Optionally, at least one frame 20 comprises a metal or plastic beam which connects two opposite corners, forming a brace 280. Two braces 280 can be combined to create an X shape inside the frame 20.

[0154] Optionally and advantageously, the superstructure 2 comprises one or a plurality of intermediate frames 29. The intermediate frame(s) 29 are positioned axially between the two end frames 20, along the stacking direction A.

[0155] The intermediate frames 29 extend in respective planes parallel two by two, and perpendicular to the stacking direction A. The edges of the intermediate frames 29 are aligned with the edges of the end frames 20, on the lower side, on the upper side and on the two lateral sides. By "lateral sides" is meant here the left and right sides, on either side of the stacking direction A.

[0156] Preferably, the end frames 20 and the intermediate frames 29 all have a similar mechanical design. Here, the superstructure 2 comprises three intermediate frames 29.

[0157] To mechanically reinforce the superstructure 2, lateral bracing 282 can be incorporated on one of the two lateral sides. The lateral braces 282 preferably connect two consecutive intermediate frames 29 and extend perpendicular to the sliding direction B. These braces preferably form an X shape.

[0158] The two end frames 20 (and, optionally, the intermediate frames 29) thus define six parallelepiped exterior faces of the superstructure 2. In their retracted position, the photobioreactors 3 are positioned in the internal volume defined by the six faces.

[0159] Thanks to the movement means 5, each photobioreactor 3 is movable in a plane perpendicular to the stacking direction A, parallel to the sliding direction B. Preferably, the sliding direction B is perpendicular to the stacking direction A, as shown in [Fig.5].

[0160] Each photobioreactor 3 is movable in translation along the sliding direction B relative to the superstructure 2, between a retracted position and a displaced position.

[0161] In the retracted position, the photobioreactor 3 is entirely contained within the parallelepiped internal volume of the superstructure 2.

[0162] In the displaced position, a portion of the photobioreactor 3 is extracted from the superstructure 2, on the side opposite the side comprising the lateral bracings 282. Preferably, any photobioreactor 3 can thus be extracted from the structure. The photobioreactors 3 are preferably extractable independently of each other.

[0163] • Lower receiving face, equipped with movement tracks

[0164] For the translational movement of the photobioreactors, the movement means 5 of each photobioreactor 3 cooperate with a receiving face 21 of the superstructure 2. The receiving face 21 is provided to support the weight of the photobioreactors.

[0165] The receiving face 21 is integral with the end frames 20, and possibly integral with the intermediate frames 29. The receiving face 21 is preferably flat and extends parallel to the ground, along the stacking direction A, from one end frame 20 to the other end frame 20.

[0166] The length D3 of the receiving face 21 (along the stacking direction A) depends on the maximum number of photobioreactors received inside the superstructure 2. Preferably but not limitingly, the length D3 is less than or equal to 10 meters. The width of the receiving face 21 is preferably substantially equal to the width DI of the end frames 20.

[0167] Preferably, at least one lower reinforcing beam 27 is disposed between the receiving face 21 and the lower side of the end frames 20, and is parallel to the stacking direction A. Here, two lower reinforcing beams 27 are provided.

[0168] On the inner side, the receiving face 21 comprises at least one rail 22 fixed to the receiving face 21, preferably a plurality of rails 22. A movement track 23 extends parallel to the sliding direction B, inside each rail 22.

[0169] The movement track 23 is provided to cooperate with movement means 5 with which a photobioreactor 3 received in the photobioreactor reception space is equipped. Here, the movement track 23 cooperates with the wheels of the photobioreactor, by moving along the movement track 23.

[0170] Preferably, a movement track 23 is provided for each photobioreactor 3. Each movement track 23 extends parallel to the sliding direction B.

[0171] In the cross-sectional view of [Fig.4], the support element 50 is shown positioned inside a rail 22, in contact with a corresponding movement track 23. The wheels of the photobioreactor 3 rest on the track 23.

[0172] The rail 22 comprises two rail portions, parallel to each other and extending along the sliding direction B. A rail floor 220 extends horizontally from one rail portion to the other rail portion.

[0173] The movement track 23 is arranged in the transverse space between the two rail parts, and projects from the rail floor 220. The movement track 23 here comprises an aluminum profile of rectangular section, the upper face of which has an elevation in the form of a pointed rail on which the bearings of the photobioreactor 3 move.

[0174] The wheels of the photobioreactor 3 can roll along the movement track 23. Thus, the photobioreactor can be moved in translation, from its retracted position (inside the superstructure 2) to its displaced position (outside the superstructure 2).

[0175] Preferably, the photobioreactor 3 can reach any position between the retracted position and the position moved along the sliding direction B, by rolling along the movement track 23.

[0176] An operator can slide the photobioreactor 3 by exerting a pulling force. The operator can pull the photobioreactor 3 towards him using gripping means provided on the photobioreactor 3 (here the handle 360 ​​visible in [Fig.2]).

[0177] The lateral portions of the rail 22 extend vertically from the rail floor 220. During translational movement of the photobioreactor 3 along the movement track 23, the lateral portions of the rail 22 laterally hold the photobioreactor 3 in position.

[0178] Preferably, the vertical edges 221 of the rail are raised relative to the support base 540 of the support element 50. The lower part of the photobioreactor 3 is thus protected laterally by the rail 22.

[0179] Preferably, a track reinforcement 222 is provided between the lower portion of the receiving face 21 and the travel track 23, in the space between the rail portions. This limits damage to the travel track 23 over time.

[0180] The inner side of the receiving face 21 comprises a plurality of aligned rails, similar to the rail 22 of [Fig.4]. Each photobioreactor received in the superstructure 2 is thus movable in translation, independently of the other photobioreactors.

[0181] Optionally, the outer side of the receiving face 21 (ground facing) comprises a fork guide 284. The fork guide 284 is provided to allow the engagement of a forklift fork, facilitating the handling of the superstructure 2.

[0182] • Upper closing face

[0183] Returning to [Fig.5], the superstructure 2 preferably comprises a closing face 24 on the upper side of the superstructure 2. The closing face 24 is integral with the end frames 20, and is optionally integral with the intermediate frames 29, when the latter are present. The closing face 24 is preferably flat, aligned with the receiving face 21 and parallel to the ground.

[0184] Preferably, the height available between the closing face 24 and the receiving face 21 is substantially equal to or slightly greater than the height L2 of the photobioreactor 3. A photobioreactor 3 can be inserted between these two faces.

[0185] Preferably, at least one upper reinforcing beam 28 is arranged above the closing face 24, on the upper side of the end frames 20. The upper reinforcing beam 28 is parallel to the stacking direction A. Here, two upper reinforcing beams 28 are provided.

[0186] Advantageously, the inner side of the closing face 24 (side opposite the receiving face 21) comprises at least one cover guide 240. Each cover guide 240 extends parallel to the sliding direction B. The superstructure 2 preferably has as many cover guides 240 as there are movement tracks 23.

[0187] The cover guide 240 is provided to guide the cover 34 along the closing face 24, during a movement of the photobioreactor 3.

[0188] In the present example, the cover guide 240 includes two guide side surfaces, extending vertically downward from the closure face 24. The two side surfaces terminate in inwardly facing hooks.

[0189] The cover 34 of the photobioreactor 3 has a hollow space passing through it, parallel to the sliding direction B, allowing the insertion of the cover guide 240. In the retracted position of the photobioreactor 3 (inside the internal volume of the superstructure 2), the entire length of the cover guide 240 is inserted into this space. hollow. During the translational movement of the photobioreactor 3 along the movement track 23, the cover 34 slides and is held laterally in position by the cover guide 240.

[0190] The support superstructure 2 described above has numerous advantages.

[0191] The superstructure 2 allows the storage of a large number of photobioreactors 3 in a reduced volume. The very compact nature of the superstructure 2 reduces the need for probes and piping. In addition, the footprint of the superstructure 2 remains very moderate. The superstructure 2 has a standardized and simple shape, and it is therefore easy to arrange several superstructures 2 grouped in the same area, in series one after the other and / or in parallel. This optimizes the occupation of the floor space on the microalgal biomass production site.

[0192] In addition, the displacement tracks 23 arranged in parallel inside the superstructure 2 allow easy extraction of a given photobioreactor, by simple traction out of the internal volume of the superstructure 2. Each photobioreactor 3 can be extracted independently of the other photobioreactors, and can then be easily replaced in its initial position.

[0193] Finally, it is possible to stack several superstructures on top of each other, as shown in the attached [Fig.6] illustrating a set of two superstructures 2 and 2' superimposed, during handling. It is therefore possible to extend the biomass production installation not only on the ground, but also vertically.

[0194] Fasteners for stacking multiple support structures

[0195] The superstructure 2 may be transported with photobioreactors 3 contained therein, or may be transported empty.

[0196] If necessary, several superstructures can be assembled and transported together. [Fig.6] illustrates the simultaneous transport of two superstructures 2 and 2' superimposed.

[0197] Advantageously, the frames 20 and 29 of the superstructures 2 and 2' may have studs 25 which can be embedded vertically two by two. Preferably, each end frame 20 and each intermediate frame 29 comprises studs 25 on the corners in the vicinity of the receiving face 21, and studs 25 on the corners in the vicinity of the closing face 24 (see [Fig.5]).

[0198] The pads 25 serve as guides for aligning the superstructure 2' above the superstructure 2.

[0199] Furthermore, a vertical assembly of the superstructures 2 and 2' can be achieved using frame fasteners 80 fixed between the frames.

[0200] [Fig.7a] is a close-up view of a first attachment area 170. The first attachment area 170 comprises a frame attachment 80, a first end of which is fixed to an end frame 20 of the superstructure 2, and a second end of which is fixed to an end frame 20' of the superstructure 2'. Attachment plates 81 are present on both end frames 20 and 20', at the corners. The frame attachment 80 is screwed between two attachment plates 81 in the corners of the end frames 20 and 20'.

[0201] [Fig.7b] is a close-up view of a second attachment area 172. The second attachment area 172 comprises a frame attachment 80 (preferably similar to the attachment of [Fig.7a]), a first end of which is attached to an intermediate frame 29 of the superstructure 2, and a second end of which is attached to an intermediate frame 29' of the superstructure 2'. The frame attachment 80 is here screwed directly onto side surfaces of the two intermediate frames 29 and 29'.

[0202] The two types of frame fasteners illustrated in Figures 7a and 7b can be used in combination, on several pairs of respective frames of the superstructures 2 and 2', in order to reinforce the mechanical strength of the vertical assembly.

[0203] Such vertical fasteners are for example used to vertically assemble several support superstructures (up to 4 floors of superstructures) on the production site, and / or to transport several support superstructures together.

[0204] For lifting and transporting them, the superstructures may include suspension attachments. Returning to [Fig.5], the superstructure 2 includes four suspension attachments 26, distributed in two pairs of attachments.

[0205] The suspension clips 26 are arranged on the closing face 24 of the superstructure 2. Here, each suspension clip 26 is arranged on a crossing between an upper reinforcing beam 28 and an intermediate frame 29. Each suspension clip 26 here has two parallel rounded corner surfaces, extending upwards from an upper reinforcing beam 28, and extending laterally from an upper part of an intermediate frame 29.

[0206] [Fig.7c] is a close-up view of a third attachment zone 174, provided with such a suspension attachment 26.

[0207] A wheel-shaped pulley 260 extends between the two parallel surfaces of the suspension attachment 26. The pulley 260 can receive a section of a crane cable 82. Two crane cables 82 can therefore be tensioned at the two pairs of suspension attachments 26, as illustrated in [Fig.6].

[0208] The suspension attachments 26 make it possible to lift and transport several superstructures assembled together, using a crane, in a reliable and simple manner.

Claims

Claims

1. Photobioreactor (3) for biomass production in a closed system, the photobioreactor (3) comprising: - a biomass container comprising a first flat wall (30) having a first edge (300) and a second flat wall (31) having a second edge (310) juxtaposed with the first edge (300), the two flat walls (30, 31) being parallel, - a base (32) extending perpendicular to the two flat walls (30, 31) from the first edge (300) to the second edge (310), the two flat walls (30, 31) and the base delimiting between them a biomass development space, the photobioreactor being characterized in that it comprises displacement means (5) integral with the biomass container in translation along a sliding direction (B),the movement means (5) being configured to guide a translational movement of the biomass container along a track (23) of a support structure (2) carrying the photobioreactor, parallel to the sliding direction (B), the movement means (5) being mounted on the base (32).,

2. Photobioreactor according to claim 1, wherein the displacement means (5) are mounted on the base (32) at a face of the base (32) opposite the first edge (300) and opposite the second edge (310).

3. A photobioreactor according to any one of claims 1 or 2, wherein the photobioreactor (3) comprises a rail (58) mounted on the base (32), the rail (58) extending longitudinally along the sliding direction (B), the displacement means (5) being arranged in an interior space of the rail (58).

4. Photobioreactor according to any one of claims 1 to 3, wherein the moving means comprise at least one wheel (5), the moving means preferably comprising at least two wheels.

5. A photobioreactor according to any one of claims 1 to 4, wherein the photobioreactor further comprises a cover (34) closing the biomass development space, the cover (34) being removable from the biomass container and extending perpendicular to the two flat walls (30, 31) opposite the base. (32).

6. Photobioreactor according to any one of claims 1 to 5, wherein the photobioreactor further comprises at least one thickness wall (36) connecting the first flat wall (30) and the second flat wall (31), the photobioreactor further comprising a gripping means (360) fixed on the thickness wall (36).

7. Photobioreactor according to any one of claims 1 to 6, in which the base (32) is formed from thermoplastic polymer, preferably from polyvinyl chloride known as PVC.

8. Photobioreactor according to any one of claims 1 to 7, wherein the first flat wall (30) and / or the second flat wall (31) are formed from thermoplastic polymer, preferably from polymethyl methacrylate known as PMMA.

9. A photobioreactor support structure (2), the support structure (2) being configured to removably receive a plurality of photobioreactors (3) for biomass production according to any one of claims 1 to 8, the support structure (2) extending longitudinally along a stacking direction (A), the support structure (2) comprising: - at least two parallel frames (20), the frames (20) being axially spaced apart along the stacking direction (A) and axially defining between them a photobioreactor receiving space, - a receiving face (21) integral with the frames (20) and extending between the frames (20) along the stacking direction (A), configured to support a plurality of photobioreactors (3), the receiving face (21) comprising a plurality of tracks (23), each track (23) extending parallel to a sliding direction (B) perpendicular to the stacking direction (A),each track (23) being configured to cooperate with movement means (5) of a photobioreactor (3) so as to guide a translation of said photobioreactor (3) relative to the support structure (2).,

10. Support structure according to claim 9, in which the support structure (2) has six parallelepiped faces, the six parallelepiped faces defining a parallelepiped internal volume, in which at least one photobioreactor (3) is movable parallel to the sliding direction (B) between a first position entirely included in the parallelepiped internal volume and a second position partially out of said volume.

11. A support structure according to any one of claims 9 or 10, wherein the support structure comprises at least one rail (22) fixed to the receiving face (21), and wherein a track (23) of the receiving face (21) extends along an interior space of said rail (22) parallel to the sliding direction (B).

12. Support structure according to any one of claims 9 to 11, wherein the number of tracks (23) is greater than or equal to 5 and less than or equal to 100, preferably greater than or equal to 20 and less than or equal to 40.

13. Support structure according to any one of claims 9 to 12, wherein the support structure further comprises a closing surface (24) fixed on the frames (20) and arranged opposite the receiving surface (21), said closing surface (24) comprising at least one cover guide (240) configured to guide in translation a cover (34) of a photobioreactor (3) received in the photobioreactor receiving space.

14. A support structure according to any one of claims 9 to 13, wherein the support structure further comprises at least one intermediate frame (29) extending in a plane parallel to each of the two frames (20), the intermediate frame (29) being arranged between the two frames (20).

15. A support structure according to any one of claims 9 to 14, wherein the support structure further comprises a suspension attachment (26) configured for attachment of a crane cable (82), so as to allow lifting of the support structure (2).

16. A support structure according to any one of claims 9 to 15, wherein at least one frame (20) is rectangular in shape and comprises two opposite corners, said frame (20) comprising a brace (280) connecting the two corners.

17. A biomass production assembly (1) comprising: - a photobioreactor support structure (2) according to any one of claims 9 to 16, the support structure (2) comprising a plurality of tracks (23), - a plurality of photobioreactors (3) according to any one of claims 1 to 8, the photobioreactors (3) being placed along the stacking direction (A) of the support structure (2), each photobioreactor (3) being in contact with a track (23) of the support structure (2) at the level of the displacement means (5) of said photobio- reactor.

18. An assembly according to claim 17, wherein the assembly comprises at least one light element (6) placed along the stacking direction (A) between two photobioreactors (3), the light element (6) being configured to provide light radiation to both said photobioreactors (3).

19. An assembly according to any one of claims 17 or 18, wherein the support structure (2) comprises a frame clip (80), wherein the assembly (1') further comprises an additional support structure (2') attached to the support structure (2) via the frame clip (80).

Images