DE102018116698B4 - Bioreactor - Google Patents

Abstract

Bioreactor (100) for cultivating algae, comprising a separating element (10) for a bioreactor (100) for cultivating algae, the separating element (10) being designed to be twisted along its longitudinal axis (13), characterized in that the separating element (10) is designed to be reflective on both sides, the bioreactor (100) comprising at least one tube (101) for passing through a suspension containing algae, the separating element (10) being arranged in the tube (101), and the suspension flowing through the tube (101). 101) is separated by the separating element (10) into a first partial flow and a second partial flow, the bioreactor (100) having a light-poor region (115) and a light-rich region (116), and wherein the separating element (10) is designed in this way that the first partial flow and the second partial flow alternately flow through the low-light area (115) and the light-rich area (116) of the bioreactor (100).

Description

Technical area

The invention relates to a bioreactor according to claim 1.

State of the art

Bioreactors are known from the prior art, which expose a suspension containing the algae to be cultivated to different light conditions at different times in order to stimulate the growth of the algae.

In their article “A novel airlift photobioreactor with baffles for improved light utilization through the flashing light effect”, Jörg Degen et all describe, for example, a so-called “flat-panel” bioreactor in which algae are subjected to a low-light and low-light system through a step-shaped formation of the partition walls of a tube be supplied to a light-rich area. However, this requires a complex installation of the partition walls. Furthermore, these are permanently installed and can therefore only be cleaned with great effort.

CN 102 134 553 B discloses a tubular photobiorector for cultivating microalgae cells, which comprises a spiral-shaped baffle plate in the sense of a separating element.

KR 101 408 800 B1 describes a photobioreactor for the cultivation of microalgae, in which a spiral-shaped separating element acts like a helical blade and is arranged continuously along a rotating shaft inside a cylinder.

Presentation of the invention: task, solution, advantages

The present invention is based on the object of improving a bioreactor in such a way that the growth of algae is optimally promoted. Furthermore, a separating element of the bioreactor should be designed in such a way that it is easy to install and clean. In addition, the bioreactor should be as compact as possible.

The above-mentioned task is achieved by a bioreactor according to claim 1.

According to the invention, the bioreactor for cultivating algae has a separating element which is twisted along its longitudinal axis.

The separating element primarily has a length along a longitudinal direction and a width along a transverse direction. The length extends in particular from a first end to a second end of the separating element. The separating element is advantageously designed such that its center line corresponds to the longitudinal axis of the separating element. Preferably the separating element is twisted helically. Furthermore, the separating element is preferably regularly twisted. This means that the angle of rotation with respect to the longitudinal axis about which the separating element is twisted is constant per unit length of the separating element.

The separating element further preferably comprises two edges, namely a first edge and a second edge. In particular, the two edges are each arranged twisted around the center line of the separating element at a distance of half the width of the separating element. The rotation of both edges is at least 360°.

Furthermore, the separating element preferably has two sides, namely a first side and a second side, which extend in particular continuously from the first edge to the second edge. The sides are primarily flat.

According to the invention, the bioreactor comprises at least one tube for passing through a suspension containing algae, the separating element being arranged in the tube and the suspension being separated into a first partial flow and a second partial flow as it flows through the tube through the separating element. The two partial flows can move around the center line of the separating element in their movement from one longitudinal end of the separating element to the other longitudinal end of the separating element. In particular, a suspension containing algae flows through the pipe.

A bioreactor is a fermenter, i.e. a device in which certain microorganisms, here algae, are cultivated or fermented under conditions that are as optimal as possible. A turbulent bioreactor is characterized by the fact that it causes a suspension containing algae to flow.

The algae are in particular microalgae, which preferably have a size of less than 100 μm, more preferably less than 50 μm, most preferably less than 20 μm. The size of the algae is to be understood in particular as a dimension of the algae in one spatial direction, with the algae having a dimension in particular in all three spatial directions, as described above.

The separating element is advantageously designed in a spiral shape. Partial flows of a suspension of a tube in a tube of a bioreactor move in a spiral motion supply path through the pipe, or around a center line of the separating element. In particular, the separating element is designed in the form of a spiral, which can be arranged within a tube of a bioreactor and can thus produce a separation of a suspension flowing in the tube and containing algae into two partial flows.

According to the invention, the bioreactor has a low-light and a light-rich area. By means of the separating element, the two partial flows alternately flow through the low-light area and the light-rich area of the pipe. This means that a controlled turbulence takes place, which means that the algae, which are in a suspension, do not have to constantly work under full load, but rather regularly reach areas of the bioreactor with little light to recover.

According to the invention, the separating element is designed to be reflective on both sides. Light that has not hit any algae can still hit an algae after being reflected on the separating element. This makes the algae's exposure to light even more efficient in a partial flow that is in the light-rich area. Both sides of the separating element are therefore designed to be reflective. This can be ensured in particular by a reflective coating. The separating element is preferably made of metal or is designed to be reflective by means of a corresponding coating.

Advantageously, the separating element has a connection region at at least one end for connecting to a further separating element and/or for fixing the separating element in a tube of the bioreactor. In particular, the separating element has a corresponding connection area at both ends. This connection area is in particular designed in such a way that it can form a releasable connection with a corresponding connection area of a further separating element and/or a fixing element for fixing the separating element in a tube of the bioreactor.

In particular, the connection area is web-shaped, with the associated connection area of a further separating element and/or a fixing element being slot-shaped, so that a connection can be established between them. The twisted design of the separating element continues in the connection area.

In particular, the separating element has a slot-shaped connection area at one end, while it has a web-shaped connection area at the opposite end. The separating element preferably has a constant thickness, while in a web-shaped connection area it has a significantly smaller thickness and/or in a slot-shaped connection area it has a significantly greater thickness. The thickness in a web-shaped connection area advantageously corresponds to the width of the slot of a slot-shaped connection area, so that they can be connected to one another.

A fixing element is to be understood in particular as an element that can be arranged in the interior of a tube of the bioreactor in order to fix the separating element. Here, the fixing element can be designed in such a way that it is located in an angle piece or a straight connecting piece, in particular a sleeve, with the angle piece connecting pipes that are at an angle to one another. Using the fixing elements, separating elements are connected to one another and fixed so that they cannot rotate and the desired twist is imposed on the algae suspension.

The partial flows can thus be exposed to different lighting conditions with the help of the separating element. By separating them into two different, and therefore smaller, partial flows, it is also ensured that all algae that are in a partial flow experience approximately the same lighting conditions. In particular, exactly one separating element is arranged in the pipe, so that exactly two partial flows flow through the pipe. The separating element is in particular aligned in the pipe in such a way that its center line lies on the center line of the pipe. The longitudinal direction of the separating element therefore corresponds to the longitudinal direction of the pipe. In particular, the separating element is arranged centrally in the tube.

Due to the twisted design of the separating element, the first partial flow and the second partial flow run in a rotational path around the center line of the pipe when flowing through the pipe.

A light-rich area is to be understood in particular as an area in which the algae are exposed to high light emission, in other words an area close to the sun, while a low-light area is to be understood as an area in which the light emission is drastically reduced, in other words an area far from the sun. The separating element is designed in such a way that when flowing through the pipe, both the first partial flow and the second partial flow alternately flow through the low-light area and the light-rich area.

The low-light area and the light-rich area are arranged in particular directly on the pipe. The at least one tube is, above all, transparent, and above all it is made of Plexiglas, so that a low-light and a light-rich area are also formed in the tube. Above all, the low-light area and the high-light area are arranged on two different, opposite sides of the tube. The sides are preferably transverse sides of the pipe. The separating element preferably separates the partial flows from one another in a transverse direction of the pipe, not in a longitudinal direction.

By providing the separating element, the first partial flow and the second partial flow are alternately exposed to the low-light and the light-rich area, namely by dividing the flow in such a way that it is ensured that the majority of the algae in a partial flow are approximately the same Experience lighting conditions. By alternating strong and low light emission, the growth of the algae is optimally stimulated, as algae prefer not to constantly work under full load, but also need rest periods. This is based on the knowledge that algae not only need a day-night rhythm, but also that periods of low light exposure during the day have a positive effect on the growth of the algae. To create the low-light area and the light-rich area, no electrical lighting source is used but rather solar radiation, which is both cheaper and stronger. The bioreactor is particularly suitable for being used outdoors.

Furthermore, the tube preferably has an inner diameter, with the separating element having a width. The width of the separating element is at least 70%, preferably at least 80%, in particular at least 90%, most preferably at least 95%, of the inside diameter of the tube. The width of the separating element corresponds in particular exactly to the inside diameter of the pipe. This ensures that the two partial flows are separated as completely as possible. The inside diameter of the tube is preferably between 1 cm and 10 cm, preferably between 2.5 cm and 7.5 cm, further preferably between 4 cm and 6 cm, most preferably the inside diameter is 5 cm.

The bioreactor preferably comprises a plurality of tubes, with at least one separating element more preferably being arranged in each tube. In particular, exactly one separating element is arranged in each tube of the bioreactor.

The tubes of the bioreactor are in particular connected to one another in such a way that a closed-loop system results. In particular, the bioreactor includes both horizontal tubes, which are arranged horizontally in the normal orientation of the bioreactor, and vertical tubes, which are arranged vertically in a normal orientation of the bioreactor. Particularly preferably, the bioreactor comprises a first horizontal tube and a second horizontal tube. The horizontal tubes primarily have a length that is between 100 cm and 300 cm, more preferably between 150 cm and 250 cm, most preferably between 175 cm and 225 cm. The length is advantageously 200 cm.

Both horizontal tubes are connected at their respective ends to a vertical tube in particular. The bioreactor therefore has four vertical tubes. A horizontal pipe is connected to vertical pipes in such a way that it is connected to an ascending pipe on one side and a descending pipe on the opposite side. An ascending pipe is understood to be a vertical pipe in which the flow rises, that is, moves from bottom to top, while a descending pipe is understood to be a pipe in which the flow descends, that is, moves from top to bottom. The ascending tubes are in particular longer than the descending tubes. The length of the descending and/or ascending pipes is primarily between 70 cm and 170 cm, in particular between 90 cm and 150 cm, and more preferably between 110 cm and 130 cm. Most preferably the length is 120 cm.

The horizontal tubes are in particular aligned parallel to one another. The same applies to the vertical pipes. A descending pipe and an ascending pipe are each connected to one another by means of an overflow element, in particular an overflow trough. The suspension, which has moved from bottom to top in an ascending pipe, can flow into the descending pipe by means of the overflow element. Since the ascending pipe is in particular longer than the descending pipe, the overflow element is therefore designed obliquely at at least one end. At least one separating element, preferably exactly one separating element, is arranged in every horizontal pipe and/or vertical pipe, in particular in every ascending and/or descending pipe.

The different pipes are particularly advantageously connected via an elbow, ie an angled, here rectangular pipe section. The separating elements in the different pipes can be in the elbows that Connect pipes to each other, be connected to each other via fixing elements.

The bioreactor also preferably has a flow element for generating a flow of the suspension. The flow element is advantageously designed as an air-lift system, which primarily comprises an ascending vertical tube and/or a descending tube. At the base of the rising pipe, air is pressed in by a pump. The increase in volume in this pipe causes the algae suspension to rise and flow over the overflow element into the descending pipe, creating a flow in the subsequent horizontal pipe. The pump performance and the ratio of the height of the air lift system to the length of the horizontal pipe are such that there is a flow velocity of at least 30 cm per second at the end of the horizontal pipe. The entire suspension containing the algae is put into flow, the separating element being used to divide the suspended suspension into two partial flows. By generating a flow of the suspension, the bioreactor is preferably a turbulent bioreactor.

In particular, the tube is formed in one piece with the separating element. This applies above all only to the transparent design, since then both the separating element and the tube must be designed to be transparent.

Best way to carry out the invention

• 1: eine perspektivische Ansicht eines Trennelementes eines Bioreaktor nach der Erfindung;
• 2: eine perspektivische Ansicht eines Verbindungsbereichs des Trennelements der 1;
• 3: eine perspektivische Ansicht eines erfindungsgemäßen Bioreaktors;
• 3a: einen Querschnitt eines Rohres des Bioreaktors nach 3;
• 4: eine Schnittansicht eines geradlinigen Verbindungsstückes;
• 4a: eine Schnittansicht eines geradlinigen Fixierelementes des Bioreaktors nach 3;
• 4b: eine Schnittansicht eines Fixierelementes nach 4a in einem geradlinigen Verbindungsstück nach 4;
• 5: eine Schnittansicht eines Winkelstücks;
• 5a: eine Schnittansicht eines gewinkelten Fixierelementes des Bioreaktors nach 5; und
• 5b: eine Schnittansicht eines Fixierelementes nach 5a in einem Winkelstück nach 5.

An exemplary embodiment of the present invention is explained in more detail below with reference to the drawings. It shows in a purely schematic representation:

• 1 : a perspective view of a separating element of a bioreactor according to the invention;
• 2 : a perspective view of a connection area of the separating element 1 ;
• 3 : a perspective view of a bioreactor according to the invention;
• 3a : a cross section of a pipe of the bioreactor 3 ;
• 4 : a sectional view of a rectilinear connector;
• 4a : a sectional view of a straight fixing element of the bioreactor 3 ;
• 4b : a sectional view of a fixing element 4a in a straight connecting piece 4 ;
• 5 : a sectional view of an angle piece;
• 5a : a sectional view of an angled fixing element of the bioreactor 5 ; and
• 5b : a sectional view of a fixing element 5a in an angle piece 5 .

1 shows a perspective view of a separating element (10) of a bioreactor according to the invention. The separating element (10) has a first end (11) and a second end (12). The separating element (10) further comprises a longitudinal axis (13) which corresponds to the center line (22) of the separating element (10).

The separating element (10) is designed to be twisted along its longitudinal axis (13). More precisely, the separating element (10) is twisted helically. The separating element (10) comprises a first edge (15) and a second edge (16), which is arranged twisted in a helical manner around the center line (29) or the longitudinal axis (13) of the separating element (10). The rotation of the two edges (15, 16) from the first end (11) of the separating element (10) to the second end (12) corresponds to more than at least 360°.

The separating element (10) also has a width (14) in a direction parallel to the longitudinal axis (13). The two edges (15, 16) are at each point at a distance of half the width (14) of the separating element (10) from the center line (22) of the separating element (10) and are arranged twisted around it. Due to the helical rotation of the separating element (10), the separating element (10) is designed as a spiral (17). The rotation of the separating element (10) is regular. This means that the angle of rotation with respect to the longitudinal axis (13) or center line (22), about which the separating element (10) is twisted, is constant per unit length of the separating element (10).

The separating element (10) has a first side (23) and a second side (24), which extend continuously from the first edge (15) to the second edge (16). A coating (18) is applied to both sides (23, 24), so that the separating element (10) is designed to be non-transparent and reflective on both sides.

At both ends (11, 12), the separating element (10) has a connecting region (19) for connecting the separating element (10) to a further separating element or a fixing element (109). At the first end (11), the connection area (19) is designed as a web-shaped connection area (20), while at the second end (12) a slot-shaped connection area (21) is formed.

In 2 is a perspective view of a connection area (19) of the separating element (10). 1 shown. This is the web-shaped connection area (20) at the first end (11) of the separating element (10). The connecting region (19) at the first end (11) has a significantly smaller thickness than the separating element (10), which has a constant thickness except for the connecting regions (19). This forms a web (20a) which can be inserted into a slot-shaped connection area (21) of a further separating element or a fixing element (109). The rotation of the separating element (10) is also maintained in the connection area (19), so that the web-shaped connection area (20) is also designed to be twisted.

3 shows a perspective view of a bioreactor (100) according to the invention. The bioreactor (100) includes several tubes (101). The bioreactor (100) has a first horizontal tube (103) and a second horizontal tube (104). The bioreactor (100) further comprises a first ascending tube (105), a second ascending tube (106), a first descending tube (107) and a second descending tube (108). In the tubes (101) there is an algae suspension, ie a suspension that contains algae to be cultivated. The tubes (101) all have the same inner diameter (102) (see 4 and 5 ).

The first horizontal tube (103) is connected at one end to the first ascending tube (105) and at its other end to the second descending tube (108), while the second horizontal tube (104) is connected at one end to the first descending tube (107) and is connected at its opposite end to the second rising tube (106). The different pipes (101) are connected in particular via an angle piece (110), i.e. an angled, here rectangular pipe piece. At least one separating element (10) is arranged within each of the tubes (101). The separating elements (10) in the different tubes (101) are connected to one another in the angle pieces (110) via fixing elements (109).

The horizontal tubes (103, 104) have the same length. The same applies to the ascending tubes (105, 106) and the descending tubes (107, 108). The ascending tubes (105, 106) are longer than the descending tubes (107, 108). An ascending pipe (105, 106) is each connected to a descending pipe (107, 108) via an overflow element (119), namely an overflow trough (120). The overflow element (119) is designed to be inclined from the ascending pipe (105, 106) to the descending pipe (107, 108).

At the base of the ascending pipes (105, 106), air is pressed by a pump (not shown), so that the algae suspension in the pipes (101) rises upwards and over the overflow element (119) into the descending pipe (107, 108) connected to it. can flow. A flow is thus generated in the adjoining horizontal pipe (104, 105).

The bioreactor (100) has a low-light area (115) and a light-rich area (116). The low-light area (115) and the light-rich area (116) are arranged in such a way that the low-light area (115) is arranged on one side in a transverse direction of the tubes (101) and the light-rich area (116) is arranged on the opposite side. The tubes (101) are designed to be transparent, so that a low-light area and a light-rich area are also formed in them, which are separated by the respective separating element (10). The separating elements (10) ensure that the algae suspension in the tubes (101) is divided into two partial flows, which alternately divide the low-light area (115) and the light-rich area (116) of the bioreactor (100) or the tubes (101). flow through. This stimulates particularly optimal algae growth.

There is a measuring area (117) on an ascending pipe (106), namely an inclined nozzle (118). This connection (118) is intended for a pH probe so that the pH value of the algae suspension can be measured at this point. Depending on the pH setpoint, carbon dioxide can be injected at a base point (121) of the ascending pipe (106). Furthermore, a further measuring area (117) is provided on one of the horizontal tubes (104), in the form of a nozzle (118), which is used for an optical density measurement, an oxygen probe and for the conductivity probe.

3a shows a cross section of a pipe of the bioreactor 3 , in which the low-light area (115) and the light-rich area (116) of the tube (101) can be seen.

In 4 a straight connecting piece (122) between two pipes (101), namely a sleeve (123), is shown. Horizontal and vertical pipes (101) can be extended using the sleeve (123). The sleeve (123) has two grooves, each with an O-ring (114), so that the sleeve (123) and the pipes (101) can be connected watertight.

4a shows a sectional view of a straight fixing element (109) of the bioreactor (100). 3 . The fixing element (109) has a connection area (111) at each end for connection to a separating element (10). At one end, the fixing element (109) has a web-shaped connection area (112), while at the opposite end it comprises a slot-shaped connection area (113). The fixing element (109) serves to fix at least one separating element (10) so that it cannot rotate within the tube (101). The separating element (10) is fixed in such a way that its center line (22) coincides with the center line of the tube (101). The fixing elements (109) are designed such that the algae suspension can flow from one end of the fixing element (109) to the other end of the fixing element (109). They thus ensure a flow through the respective pipe (101) in which it is arranged.

4b shows a sectional view of a fixing element 4a in a straight connecting piece 4 . The fixing element (109) is inserted into a straight tube (101) of the bioreactor (100). The fixing element (109) can be formed in one piece with the tube (101).

In 5 An angle piece (110) is shown which has two grooves, each with an O-ring (114).

5a shows a sectional view of an angled fixing element of the bioreactor 3 . The fixing element (109) of 5 is analogous to the fixing element (109). 4 designed except for the difference that the fixing element (109) is angled.

5b Recreates a sectional view of a fixing element 5a in an angle piece (110). 5 The angled design of the angle piece (110) and the fixing element (109) makes it possible to fix and connect separating elements that are arranged in tubes (101) that are at an angle to one another.

Reference symbol list

10

Separator

11

First ending

12

Second ending

13

Longitudinal axis

14

Width

15

First edge

16

Second edge

17

spiral

18

Coating

19

Connection area

20

Bar-shaped connection area

20a

web

21

Slot-shaped connection area

22

Centerline

23

first page

24

second page

100

Bioreactor

101

Pipe

102

Inner diameter

103

First horizontal pipe

104

Second horizontal pipe

105

First ascending pipe

106

Second ascending pipe

107

First descending pipe

108

Second descending pipe

109

Fixing element

110

Elbow

111

Connection area

112

Bar-shaped connection area

113

Slot-shaped connection area

114

O-ring

115

Low-light area

116

Bright area

117

Measuring range

118

Support

119

Overflow element

120

Overflow pan

121

footing point

122

straight connector

123

sleeve

Claims (7)

Bioreactor (100) for cultivating algae, comprising a separating element (10) for a bioreactor (100) for cultivating algae, wherein the separating element (10) is designed to be twisted along its longitudinal axis (13), characterized in that the separating element (10 ) is designed to be reflective on both sides, the bioreactor (100) comprising at least one tube (101) for passing through a suspension containing algae, wherein the separating element (10) is arranged in the tube (101), and wherein the suspension is separated into a first partial flow and a second partial flow by the separating element (10) as it flows through the tube (101), wherein the bioreactor (100) a low-light area (115) and a light-rich area (116), and wherein the separating element (10) is designed such that the first partial flow and the second partial flow alternately cover the low-light area (115) and the light-rich area (116) of the bioreactor (100) flow through. Bioreactor (10) after Claim 1 , characterized in that the separating element (10) is spiral-shaped. Bioreactor (10) according to one of the preceding claims, characterized in that the separating element (10) has a connection region (19) at at least one end for connecting to a further separating element and/or for fixing the separating element (10) in a tube (101). of the bioreactor (100). Bioreactor (100) according to one of the preceding claims, characterized in that the tube (101) has an inner diameter (102), wherein the separating element (10) has a width (14), and wherein the width (14) of the separating element (10 ) is at least 70%, preferably at least 80%, in particular at least 90%, most preferably at least 95%, of the inside diameter (102) of the tube (101). Bioreactor (100) after Claim 4 , characterized in that the inner diameter (102) is between 1 cm and 10 cm, in particular between 2.5 cm and 7.5 cm, further preferably between 4 cm and 6 cm, most preferably 5 cm. Bioreactor (100) according to one of the preceding claims, characterized in that the bioreactor (100) has a plurality of tubes (101), a separating element (10) being arranged in each tube (101). Bioreactor (100) according to one of the preceding claims, characterized in that the bioreactor (100) has a flow element for generating a flow of the suspension.

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