EP2155853A2

EP2155853A2 - Assembly and method for the three-dimensional distribution of light in a liquid medium

Info

Publication number: EP2155853A2
Application number: EP08758393A
Authority: EP
Inventors: Hilmar Franke; Christian Schneider; Armed Wagner
Original assignee: Universitaet Duisburg Essen
Current assignee: Universitaet Duisburg Essen
Priority date: 2007-05-07
Filing date: 2008-05-07
Publication date: 2010-02-24
Also published as: DE102007050484A1; WO2008135276A3; WO2008135276A2

Abstract

The invention relates to an assembly and a method for the three-dimensional distribution of light in a liquid medium such as an algae suspension and/or for the production of biomass. Light, in particular sunlight, is conducted in a container filled with the medium, by means of fibre optics. The light is distributed three-dimensionally in the container. To achieve this, the fibre optics terminate in different areas inside the container. Alternatively or in addition, the light is introduced via gas bubbles, said gas being supplied in particular via hollow fibre optics.

Description

Arrangement and method for the three-dimensional distribution of light in a liquid medium

The present invention relates to an arrangement and a method for the three-dimensional distribution of light in a liquid medium, such as an algal suspension, and / or for the production of biomass and a use of such an arrangement or method for the conversion of carbon dioxide into biomass.

The present invention is particularly concerned with mimicking photosynthesis for binding carbon dioxide. It is known to illuminate an algae suspension for this purpose in order to stimulate the growth of the algae. The algae consume carbon dioxide for growth and biomass production. In order to supply all algae in the algae suspension with light and carbon dioxide, the algal suspension can be circulated very strongly and / or the surface of the algae suspension can be made as large as possible. However, this can be plant and / or procedural or energy consuming.

The present invention is based on the object, an arrangement and a method for the three-dimensional distribution of light in a liquid medium, such as an algal suspension, and / or for the production of biomass and a use of such an arrangement or such a method for the conversion of carbon dioxide in Indicate biomass, wherein a simple structure, a simple, cost-effective and / or energy-saving process flow and / or high efficiency is or will be possible.

The above object is achieved by an arrangement according to claim 1 or 15, by a method according to claim 20 or 39 or by a use according to claim 40. Advantageous developments are the subject ^~ RESISTING ^~ d ^~ ^~ the dependent claims: -

8BBTATtQUNQSKOPfE A basic idea of the present invention is to use photoconductive fibers for the supply of light. This fiber concept leads in particular to two advantages.

The transport of light to the liquid medium can take place over long lengths, for example of a few 100 m. It is thus possible, for example, to use light collectors or collectors, such as collector mirrors, for the concentration of sunlight in order to collect and supply larger amounts of light to the liquid medium.

Furthermore, the fibers permit a three-dimensional illumination of the liquid medium, ie a three-dimensional distribution of the light in the liquid medium. The light is thus distributed in different areas of space, in particular depths, within the medium.

The three-dimensional distribution of the light or illumination of the medium thus takes place in contrast to the hitherto customary at least substantially two-dimensional illumination from a surface or side actually three-dimensionally and thus with much improved distribution and effectiveness.

For the three-dimensional distribution of the light, it is provided according to an embodiment variant that the fibers terminate in different spatial regions, in particular in depths, preferably vertically offset, in the liquid medium. Thus, a particular tree-like or optimal distribution of the light in the liquid medium in a desired spatial illumination range can be achieved.

A further embodiment variant, which can also be implemented alternatively or independently, provides that the light is distributed in three dimensions in the liquid medium by means of gas bubbles. The supply of the gas and the light takes place preferably at the same time via hollow fibers.

A proposed use of the arrangement or the method are characterized in that a liquid medium with algae, such as an algal suspension, is used, wherein light in the medium three-dimensional and wherein carbon dioxide is introduced in the form of gas bubbles in the medium to stimulate the growth and / or proliferation of algae and thereby form biomass. Thus, a very effective formation of biomass and / or binding of carbon dioxide can take place.

Further aspects, advantages and features and characteristics of the present invention will become apparent from the claims and the following description of preferred embodiments with reference to the drawing. It shows:

Fig. 1 is a schematic representation of a proposed arrangement according to a first embodiment;

Fig. 2 is a schematic representation of a proposed arrangement according to a second embodiment;

FIG. 3 shows a schematic, not to scale, section of a light-conducting fiber of the arrangement according to FIG. 2; FIG.

4 shows a schematic, not to scale, section of another light-conducting fiber of the arrangement according to FIG. 2; and

Fig. 5 is a schematic representation of a proposed arrangement according to a third embodiment.

In the figures, the same reference numerals will be used for the same or similar components, components and the like. In particular, there are corresponding or comparable advantages, even if a repeated description is omitted.

Fig. 1 shows a schematic, not to scale representation of a proposed arrangement 1 according to a first embodiment. The arrangement 1 serves the three-dimensional distribution of light 2 (schematically in Fig. 1 indicated) in a liquid medium. 3

The medium 3 is in particular a suspension or the like. Accordingly, the term "liquid" is to be understood in a broad sense to understand, so that in particular suspensions, dispersions or other mixtures or substances are included with liquid phases or proportions.

The medium 3 is preferably photoactive and / or biologically active. In particular, a reaction that requires photosynthesis or another light 2 may take place in the medium 3. In particular, the medium 3 contains for this purpose a biologically active species, in particular algae, other bacteria or the like.

In particular, the medium 3 is aqueous or contains water and / or strong light-scattering.

An algal suspension is particularly preferably used as medium 3. In particular, the medium 3 contains an algae mixture culture, which preferably occurs at least in similar form in rivers, ponds or the like. Such mixed cultures are namely particularly resistant to environmental influences, diseases and / or other disorders.

Since the arrangement 1 is preferably used with algae or with an algae suspension as the medium 3, the following description is primarily focused on the algae growth induced by the induced light 2. However, these statements apply accordingly to other species or photo- or bioactive media 3.

The arrangement 1 has light-conducting fibers 4 for the supply of the light 2. In the first embodiment, several or all of the fibers 4 terminate in different spatial regions, in particular at least partially in different depths and / or vertical planes, in the medium 3. This permits a three-dimensional distribution of the light 2 in the medium 3, as shown in FIG. playfully, only schematically indicated.

^ V! Orzugsw-else-SÜκLdie_Easern_4_flexibel. However, in principle, rigid light-conducting rods - at least in sections and / or at the outlet end into the medium 3 - can be used. More preferably, the fibers 4 terminate at different levels within the medium 3. However, the fibers 4 may all end differently or irregularly.

Starting from a bundle (main bundle) 5 of fibers 4, branching or branching into individual bundles 6 and / or individual fibers 4 takes place, as exemplified in FIG. 1. In order to achieve an optimal distribution of the light 2 in the medium 3, the fibers 4 preferably terminate individually, ie separately in the medium 3. However, several fibers 4 may end together in the medium 3, for example as individual bundles 5.

The light emerges at least substantially or exclusively at the end of the respective fiber 4 and illuminates the medium 3 in the respective spatial region, as indicated by dashes in FIG. 1.

Depending on the bending or curvature, material, surface, surface roughening or the like, the fibers 4 can also emit more or less light laterally along the respective fiber 4. Even so, an optimized three-dimensional distribution of light 2 in the medium 3 can take place. With appropriate design of the fibers 4, it is even possible that at least substantially the total light is already emitted laterally over the running in the medium 3 lengths of the respective fiber 4 and optionally only a relatively small proportion at the end of the respective fiber 4 in the medium third is emitted. In this case, the fibers 4 preferably extend substantially over longer distances parallel to each other or, for example, coiled or meandering through the medium 3 and may possibly even all end in a plane or depth in the medium 3.

Experiments have shown that the light exit surfaces - especially the ends - of the fibers 4 are not colonized by the algae. Accordingly, excessive purification or algae exemption is not required. Rather, it results in a self-organizing system that uses as efficiently as possible the introduced light 2 for algae growth. The fibers 4 can dive loosely into the medium 3 or hang into it, optionally also as a bundle 5 or 6, which then branch in particular.

Preferably, the arrangement 1 in particular lattice- or rod-like mounts 7 in the medium 3, which are arranged in particular in different planes or depths to hold the fibers 4 or bundles 5, 6 or lead.

Particularly preferably, the holders 7 form intermediate bottoms in a container or tank 8 with the medium 3 in order to allow the fibers 4 or bundles 5 or 6 to end in different spatial regions within the medium 3.

If necessary, the fibers 4 or bundles 5, 6 can be movable at least in the end regions in the medium 3, in particular by a flow of the medium 3.

The supply or introduction of the fibers 4 or bundle 5/6 is preferably carried out from above, in the embodiment by an upper bracket or cover 9 or the like.

The fibers 4 or bundles 5/6 preferably extend at least substantially vertically from top to bottom in the medium 3. This is particularly advantageous when the density of the fibers 4 is greater than the density of the medium 3, that is not float.

However, it is also possible in principle for the fibers 4 or bundles 5/6 to extend from the bottom to the top into the medium 3 and / or in another way-for example transversely-into the medium 3 or at least in sections thereof.

The fibers 4 are preferably made of plastic, glass or other material suitable for light conduction or structure. In particular, it is also possible to use composite materials or composite structures, for example with laminations. Alternatively, ie independently, or in addition to the three-dimensional distribution of the light 2 in the medium 3 through the fibers 4, the fibers 4 or bundles 5/6 permit an optimized supply of the light 2.

In the illustrated example, sunlight is preferably used for illuminating the medium 3 or the algae, even if basically any other light can be used. In this context, it should be noted that the term "light" is preferably to be understood in a broad sense that not only visible light but, for example, alternatively or additionally also infrared light and / or ultraviolet light according to the medium 3 can be supplied. In general, the energy supply via the fibers 4 of the medium 3 can also serve purposes other than the photosynthesis and / or stimulation of the biological growth and / or the conversion of carbon dioxide into biomass provided in the illustration example.

The arrangement 1 preferably has a Lichtsammeieinrichtung, in particular a collector mirror 10, for collecting sunlight, as shown schematically in Fig. 1. The collected sunlight or other light from another illumination device can then be passed through the fibers 4 or in particular a bundle 5 or 6 to the container or tank 8 with the medium 3, in particular with very low losses. In particular, such leads of several 100 m are possible. This is very advantageous, especially in the case of a large amount of light, since correspondingly large areas, light collecting devices or the like are required and / or corresponding structural conditions must and / or can be taken into account. In particular, it is thus possible to accommodate the container or tank 8 with the medium 3 in a building, not shown, or the like and, for example, to use sunlight for illumination.

The arrangement 1 preferably has a device 1 1 for the introduction of gas, which contains in particular carbon dioxide or consists thereof. For example, flue gas, sewage gas, biogas, air or the like can be initiated. In the illustrated example, the device 11 has in particular a bottom, a sieve 12 or another suitable introduction means, to introduce or dispense the gas, in particular in the form of gas bubbles 13 in the medium 3, as indicated schematically in Fig. 1.

The gas supply or -einleitung takes place in particular at the bottom and / or at a certain depth, preferably of at least 5 to 6 m, to allow a good exchange of gas or a good supply of the medium 3 and thus the algae with the gas.

If necessary, the gas above the medium 3 - in the Darstellungsbei- game, for example, above the cover 9 or within the container or tank 8 sucked and fed back through the device 11, so recirculated to a particularly good utilization or a particularly good degradation of Gas, in particular of carbon dioxide to achieve.

Hereinafter, a second embodiment of the proposed arrangement 1 and the method for the three-dimensional distribution of light in the medium 3 and / or for the generation of biomass using the scheme of FIG. 2 will be explained in more detail. In particular, only essential differences from the first embodiment will be described, so that the previous statements and explanations apply in particular corresponding or supplementary.

In the first embodiment, the fibers 4 or bundles 5, 6 in particular branch out in a tree-like manner in order to distribute the light 2 in different spatial regions within the medium 3-ie three-dimensionally-in the medium 3. In the second embodiment, it is alternatively or additionally provided that the light is introduced via gas bubbles 13 and, in particular, is distributed three-dimensionally in the medium 3. The introduction or generation of the gas bubbles 13 is preferably via hollow fibers 4, but can also be done in other ways.

In the second embodiment, the fibers 4 for supplying the light 2 are preferably at least partially and / or partially hollow in order to be able to supply not only the light 2 but also the gas at the same time. In particular, there is a light pipe in the jacket of the hollow fibers 4, which are indicated schematically in Fig. 2, not to scale. When the gas is introduced into the medium 3, the gas bubbles 13 form. The gas bubbles 13 preferably initially have a size of essentially 1 to 10 .mu.m, in particular 2 to 5 .mu.m. At this size, the gas bubbles 13 form particularly suitable sound boxes for the light to be picked up.

The hollow fibers 4 simultaneously emit the light at their ends in the areas where the gas bubbles 13 are formed. Thus, the gas bubbles 13 can be quasi "filled" with light 2. A kind of fog or cloud of glowing gas bubbles 13 is generated.

The glowing gas bubbles 13 - by way of example, a luminous gas bubble 13 is shown in an enlarged detail in FIG. 2 - migrate upwards through the medium 3. In this case, the gas bubbles 13 tend to be larger due to the decreasing fluid pressure. On the other hand, the gas can dissolve in the medium 3 or be absorbed by the algae or the like, so that the gas bubbles 13 accordingly tend to be smaller. If necessary, these two effects can be compensated for, so that the size of the gas bubbles 13 remains at least largely the same.

In order to achieve the desired gas bubble size or at least to support its formation, the introduction of the gas preferably takes place at a depth of about 3 to 50 m, preferably 5 to 10 m, into the medium 3.

The introduction of the gas is again, as in the first embodiment, preferably on the bottom side or from below.

For the formation of the gas bubbles 13 or manipulation of the sizes of the gas bubbles 13, if necessary, a sieve 12 or the like can be used.

Alternatively or additionally, the desired gas bubble size can be very easily influenced by appropriate selection of the inner diameter of the hollow fibers 4. 3 and 4 show by way of example two possible, different cross-sections of the hollow fibers 4, each in a schematic, not to scale representation.

In the embodiment of FIG. 3 is a so-called band-gap fiber. The gas is preferably carried out exclusively via the inner or central channel 14, but if necessary also via the other peripheral hollow channels 15 of this fiber 4. In this case, the light pipe is then only in the mantle of the fiber 4th

Alternatively or additionally, the light pipe can be made via the peripheral hollow channels 15.

4 shows a "conventional" hollow fiber 4. The gas supply takes place here via the central channel 14. The light conduction takes place in the jacket of the fiber 4th

In order to achieve the desired gas bubble size, the inner diameter I of the hollow fibers 4 or central channels 14 is preferably at most 10 .mu.m, in particular substantially 5 to 9 .mu.m.

In the illustrated embodiment, the arrangement 1 or device 11 preferably has a feed device 16, in particular with a housing under gas pressure, in order to introduce the gas into the hollow fibers 4 and to couple the light 2 into the fibers 4.

The gas is supplied, for example via a pump 17 or the like, and in particular enters the front side into the channels 14 and 15 a.

The light 2 becomes, for example, via light-conducting fibers 4 or a fiber bundle 6 or the like - in turn, in turn, from a light collecting device, such as the collector mirror 10-or-V-on-another EB lighting device, which is only schematically indicated in FIG - added or forwarded. Fig. 2 shows the coupling only very schematically. In particular, the light is introduced on the front side into the beginnings of the hollow fibers 4. The container or tank 8 or the medium 3 is preferably associated with a circulation device, such as a circulation pump 18, an agitator or the like. Thus, a sufficient and in particular growth-demanding movement of the medium 3 or the algae suspension can be ensured.

Fig. 5 shows a schematic representation of a third embodiment of the proposed arrangement 1 or device 11. Here, the production and introduction of the gas bubbles 13 preferably via a grid, a screen 12 a hole bottom or the like. In particular, it may also be an intermediate floor act. Thus, the pressure losses occurring during the supply of the gas in the second embodiment due to the hollow fibers 4 can be avoided or at least minimized.

In the second and third embodiments, in particular the light coupling into the gas bubbles 13 takes place in that the gas is passed through small holes or channels in an optically transparent or light-conducting material and forms the gas bubbles 13 at the exit and receives light 2.

Particularly preferably, the sieve 12 or the perforated bottom of a plate, and / or transparent material is preferably made of plastic, in particular with a thickness of about 3 to 10 mm. The plate preferably has a plurality of small holes with a diameter of at most 50 microns. The gas enters the medium 3 through these holes. The illumination preferably takes place through the transparent plate material and / or on the gas side. Over the length of the holes or holes - ie over the thickness of the plate - quasi "hollow optical waveguide" are formed with the flowing gas as the interior and the bottom plate as an optical sheath. Thus, the resulting gas bubbles 13 can optically couple to the light field or light 2 and vice versa so the light 2 can be absorbed by the gas bubbles 13.

Otherwise, in the third embodiment, the explanations and remarks on the second embodiment apply in particular correspondingly or in addition. In particular, again a collector mirror 10 or any other suitable lighting device for the supply of light - optionally again on fiber bundles 6 or the like. - Are used.

Alternatively or additionally, however, the light 2 can also be coupled in any other way, in particular possibly also laterally, into the optically translucent or transparent plate with the holes through which the gas is introduced into the medium 3 to form the gas bubbles 13 become.

In the third embodiment, pipes or other protrusions, extensions or the like, for example with a length of about 1 to 2 m, can be additionally attached or projected upwards or projecting or connected in some places of the floor, in which fiber optic cables are routed. The end face of these tubes can then be formed, for example, with a hole construction or a structure such as the base plate. Thus, the gassing and exposure of the reactor volume or the medium 3 can be made uniform. Alternatively or additionally, a plurality of intermediate floors, which are formed according to the second or third embodiment and are arranged or offset, for example, at different heights or depths, can be used.

According to a further embodiment, much smaller gas bubbles 13 are formed. The initial diameter of the gas bubbles 13 is for example 0, 1 to 10 microns, preferably less than 1 micron, in particular substantially 0.2 to 0.6 microns.

Such small gas bubbles 13 can be made in particular by introduction in a corresponding depth, for example about 50 m or more, in the medium 3. Alternatively or additionally, the medium 3 can also be pressurized.

Particularly preferably, the introduction of the gas takes place at a pressure of the medium 3 of about 50 to 800 kPa. More preferably, the pressure of the medium 3 at which the gas is introduced is at least about 500 kPa and more to form very small gas bubbles 13. Due to the small size of the gas bubbles 13, it is possible to stimulate them by direct exposure to light, in particular sunlight, to resonance absorption, so that the light is transported when ascending the gas bubbles 13 into the interior of the reactor or up through the medium 3. The exposure of the gas bubbles 13 can in particular be effected again via optical fibers 4 and / or in any other way.

It should be noted that the gas bubbles 13 can form resonators for the incident light 2. The resonance frequencies depend on the diameter of the gas bubbles 13. In order to be able to absorb not only monochromatic light, gas bubbles 13 with different diameters, in particular with a diameter spectrum covering the supplied light spectrum, are preferably produced.

In the described embodiments, the photosynthesis can be imitated by means of a technical device, namely from carbon dioxide and water under the action of light biomass or CH ₂ O-containing compounds and oxygen to produce. Accordingly, the proposed arrangement 1 can also work or be referred to as a bioreactor, in particular as a fiber-optic photo-bioreactor.

Particularly preferably, sunlight is used, which is collected in particular by means of concentrators, collector mirrors 10 or the like and fed to the medium 3 and in particular is introduced into this, as already explained with reference to the two embodiments. Alternatively or additionally, the sunlight may also be collected through a network of fluorescent fibers.

The concentrated sunlight or other light is preferably in opti see optical fibers - in the present invention referred to as 4 - fed - and in particular in the form of a bundle 5/6 the bioreactor, in this case the container or tank 8 with the medium 3, fed ,

Particularly preferably, the algal suspension in the entire reactor volume, ie in the entire container 8, be illuminated by means of fiber technology.

In particular, this is done by the fibers 4 in different Spaces in the container 8 ends or branch, as explained with reference to the first embodiment. Alternatively or additionally, the spatial distribution of the light 2 in the medium 3 can also be effected by means of gas bubbles 13, in particular by a mist of luminous bubbles, as explained with reference to the second embodiment.

This achieves a three-dimensional illumination. In conventional illumination from one side or at least substantially only from one plane, however, only a zone of a few mm penetration depth is achieved because of the high attenuation constant of the algal suspension.

As already explained, the optical fibers have a twofold meaning in the present invention. The individual effects can also be used independently or exploited.

First, the fibers 2 provide effective light transport over long lengths. Large quantities of carbon dioxide, such as a coal-fired power plant, require a lot of light to bind carbon dioxide. This requires correspondingly large areas for collecting the sunlight with correspondingly long transport distances of more than a few 100 m.

Secondly, the optical fibers 4 serve to illuminate a three-dimensional volume in the container 4. This is done by the preferably tree-like branching and / or by means of the gas bubbles 13.

These principles make the arrangement 1 or the bioreactor scalable.

The described invention is intended to help solve the carbon dioxide problem. In particular, the proposed arrangement 1 and the proposed method for the degradation of carbon dioxide from the flue gas of fossil power plants are suitable.

To reduce carbon dioxide from flue gas, the flue gas can optionally be simply blown from below into the container 8, as indicated in the two embodiments. Another advantage of the present invention is that not only can carbon dioxide be degraded, but that the biomass produced can also be used as a raw material for fuel, bioethanol, biodiesel or the like.

The strong scattering of the medium 3 supports an at least largely uniform or complete illumination of the medium 3 or of the container 8.

It should be noted that, if necessary, the IR fraction is separated from the sunlight, and can be used, for example, for other purposes, in particular for drying the biomass produced, such as algae, or the like.

As already mentioned, in addition to or as an alternative to the emission of the light at the fiber ends, a lateral emission can also take place. This can be achieved in particular by correspondingly large curvature of the fibers 4. If necessary, the fibers 4 can accordingly also be strongly curved, in particular coiled, guided or run in the medium 3.

There is proposed an arrangement and a method for the three-dimensional distribution of light in a liquid medium, such as an algal suspension, and / or for the production of biomass. Light, especially sunlight, is conducted by means of optical fibers in a container with the medium. The light is distributed three-dimensionally in the container. For this purpose, the fibers end in different spatial areas within the container. Alternatively or additionally, the light is introduced via the bubbles, wherein the gas is supplied in particular via hollow optical fibers.

Individual features and aspects of the described embodiments and variants can also be combined with one another as desired and / or used in other arrangements or methods.

Claims

claims:

1. Arrangement (1) for the three-dimensional distribution of light (2) in a liquid medium (3) and / or for the production of biomass, with lichtleiten- fibers (4) for supplying the light (2), wherein the light (2 ) can be distributed into different spatial areas within the medium (3).

2. Arrangement according to claim 1, characterized in that the medium (3) is photoactive and / or biologically active.

3. Arrangement according to claim 1 or 2, characterized in that the medium (3) contains at least one biologically active species, in particular algae.

4. Arrangement according to one of the preceding claims, characterized in that several or all fibers (4) in different and / or not lying in a plane space areas, in particular depths, in the medium (3) end.

5. Arrangement according to one of the preceding claims, characterized in that the fibers (4) via preferably grid or rod-like holders (7), in particular in different planes or depths, are held within the medium (3).

6. Arrangement according to one of the preceding claims, characterized in that the fibers (4) are made of glass or plastic.

7. Arrangement according to one of the preceding claims, characterized in that the fibers (4) extend at least substantially vertically in the medium (3).

& Arrangement according to one of the preceding claims, characterized in that a bundle (6) of the fibers (4) branches into individual bundles (5) and / or individual fibers (4) which are arranged in different and / or non-in-plane spatial regions. especially depths in which medium (3) ends.

9. Arrangement according to one of the preceding claims, characterized in that the fibers (4) and / or bundles (5, 6) at least in end regions in the medium (3), in particular by a flow of the medium (3), are movable.

10. Arrangement according to one of the preceding claims, characterized in that the arrangement comprises means (11) for introducing preferably carbon dioxide-containing gas, in particular carbon dioxide, flue gas, sewage gas, biogas or air, in the medium (3).

11. Arrangement according to one of the preceding claims, characterized in that the fibers (4) formed hollow and by this gas and at the same time the light (2) in the medium (3) can be introduced.

12. Arrangement according to claim 1 1, characterized in that the fibers (4) have an inner diameter of at most 10 microns.

13. Arrangement according to one of claims 10 to 12, characterized in that the gas can be introduced into a bubble, distributed and / or deliverable.

14. Arrangement according to one of the preceding claims, characterized in that the light (2) of gas bubbles (13) is aufhehmbar.

15. Arrangement (1) for the three-dimensional distribution of light (2) in a liquid medium (3) and / or for the production of biomass, in particular according to one of the preceding claims, characterized in that the light (2) by means of gas bubbles (13) in the medium (3) can be distributed.

16. Arrangement according to one of claims 13 to 15, characterized marked, that the gas bubbles (13) initially a size of substantially 0.1 .mu.m to 10 .mu.m, preferably about 1 to 8 .mu.m, in particular about 2 to 5 microns, exhibit.

17. Arrangement according to one of the preceding claims, characterized in that the gas via a bottom or a sieve (12) and / or in a Depth of 3 to 50 m, preferably 5 to 10 m, and / or at a pressure of the medium (3) of about 50 to 800 kPa in the medium (3) can be introduced.

18. Arrangement according to one of the preceding claims, characterized in that the light (2) via a preferably common fiber bundle

(5, 6) can be fed to the fibers (4).

19. Arrangement according to one of the preceding claims, characterized in that the arrangement (1) has a Lichtsammeieinrichtung, in particular a collector mirror (10) for receiving sunlight, which is introduced into the medium (3).

20. Method for the three-dimensional distribution of light (2) in a liquid medium (3) and / or for the production of biomass, wherein the light (2) is supplied via fibers (4) which are located in different spatial areas within the medium (3) end, and / or wherein the light (2) by means of gas bubbles (13) within the medium (3) is distributed.

21. The method according to claim 20, characterized in that the medium (3) is photoactive and / or biologically active.

22. The method according to claim 20 or 21, characterized in that the medium (3) contains at least one biologically active species, in particular algae.

23. The method according to any one of claims 20 to 22, characterized in that fibers (4) in different depths and vertically offset ends in the medium (3).

24. The method according to any one of claims 20 to 23, characterized in that the fibers (4) via preferably grid or rod-like holders (7), in particular at different levels or depths, are held within the medium (3).

25. The method according to any one of claims 20 to 24, characterized in that the fibers (4) are made of glass or plastic.

26. The method according to any one of claims 20 to 25, characterized in that the fiber (4) extend at least substantially vertically in the medium (3).

27. The method according to any one of claims 20 to 26, characterized in that a bundle (5, 6) of the fibers (4) in individual bundles (5) and / or individual fibers (4) branches, which in different spatial areas, in particular depths, in the medium (3).

28. The method according to any one of claims 20 to 27, characterized in that the fibers (4) and / or bundles (5, 6) at least in end regions in the medium (3), in particular by a flow of the medium (3), are movable ,

29. The method according to any one of claims 20 to 28, characterized in that gas, in particular carbon dioxide, flue gas, sewage gas, biogas or air, in the medium (3) is introduced.

30. The method according to any one of claims 20 to 29, characterized in that the fibers (4) are hollow and are introduced by this gas to form the gas bubbles (13) and at the same time the light (2) in the medium (3).

31. The method according to claim 30, characterized in that the fibers (4) have an inner diameter (I) of at most 10 microns.

32. The method according to any one of claims 20 to 31, characterized in that the light (2) of gas bubbles (13) is received.

33. The method according to any one of claims 20 to 32, characterized in that the gas bubbles (13) each form a resonance space for the light (2).

34. The method according to any one of claims 20 to 33, characterized in that the gas bubbles (13) are introduced on the bottom side.

35. The method according to any one of claims 20 to 34, characterized in that the gas bubbles (13) initially have a size of substantially 0, 1 to 10 microns, preferably about 1 to 8 microns, in particular 2 to 5 microns.

36. The method according to any one of claims 20 to 35, characterized in that the gas bubbles (13) by means of a sieve (12) are generated or formed.

37. The method according to any one of claims 20 to 36, characterized in that the gas bubbles (13) at a depth of 3 to 50 m, preferably 5 to 10 m, and / or at a pressure of the medium (3) of about 50 to 800 kPa are introduced into the medium (3).

38. The method according to any one of claims 20 to 37, characterized in that the light (2) via a preferably common fiber bundle (5, 6) is supplied to the fibers (4).

39. The method according to any one of claims 20 to 38, characterized in that sunlight is absorbed and used as light (2), in particular via the fibers (4) to and / or in the liquid medium (3) is passed.

40. Use of an arrangement according to one of claims 1 to 19 or a method according to any one of claims 20 to 39 for the conversion of carbon dioxide into biomass, wherein a liquid medium (3) is used with algae, wherein light (2) in the Medium (3) is distributed in three dimensions and wherein carbon dioxide containing or consisting of gas in the form of gas bubbles (13) in the medium (3) is introduced to stimulate the growth and / or multiplication of algae and thereby form biomass.