JPH07227269A - Incubator for photosynthetic organisms - Google Patents

Abstract

(57) [Summary] [Objective] To provide a culture device for a photosynthetic organism, which can efficiently supply light and carbon dioxide in culturing a photosynthetic organism and can reduce the energy required for the culture. There is. [Structure] A liquid film forming plate (2) for causing a culture solution (4) containing a photosynthetic organism to flow down along a surface in a liquid film, a culture solution supply means (5) for supplying a culture solution containing a photosynthetic organism to its upstream end, and the liquid. A culture apparatus 1 for photosynthetic organisms, comprising: a light source (7) for irradiating the film (6) with light; a light reflecting surface (25) is provided around the liquid film forming plate, and the liquid film forming plate and the light reflecting surface are provided. An emission end 28 of an optical fiber 27 that propagates the light from the light source is arranged in between.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a culture device for efficiently culturing photosynthetic organisms, and is a technique for culturing photosynthetic organisms in a liquid film of a culture solution formed on the surface of a liquid film forming plate.

[0002]

2. Description of the Related Art Conventionally, a large amount of photosynthetic organisms such as unicellular algae such as chlorella are cultured, and useful substances such as sugars, fermentation industrial substrates, proteins, unsaturated fatty acids and pigments are produced from the cultured photosynthetic organisms, or photosynthetic organisms. Wastewater treatment is being carried out. In addition, as the problem of global warming due to the large amount of carbon dioxide emission is highlighted, research and development of exhaust gas treatment technology for absorbing and assimilating carbon dioxide in exhaust gas by photosynthetic organisms is underway. In the production of useful substances, wastewater, and exhaust gas purification using such photosynthetic organisms, how to efficiently supply light and carbon dioxide to the photosynthetic organisms in the culture solution in order to increase the culture efficiency Is important.

Conventionally, in the culture of chlorella or the like, as a method of supplying light into the culture tank, a method of irradiating light into the culture tank by immersing a large number of optical fibers or light diffusion rods in the culture tank, photosynthesis There are a method of irradiating sunlight and light of an artificial light source from the outside by stirring a culture solution containing organisms, and a method of irradiating light by installing a light source in a culture tank. Further, as a method of forcibly supplying a gas containing carbon dioxide into the culture solution, there is a method of forcibly ventilating the gas from the lower part in the culture tank.

[0004]

However, among the above-mentioned methods for supplying light, when a method of immersing an optical fiber or a light diffusing rod and when a light source is installed in a tank, the propagated photosynthetic organisms are converted into an optical fiber. There has been a problem that the irradiation efficiency is reduced by adhering to the surface or the surface of the rod. Also,
The method of irradiating sunlight or light from an artificial light source from the outside of the culture tank requires that the culture solution be constantly stirred in order to make the light conditions uniform, and this stirring has the drawback of damaging cultured organisms, and There is a problem that high energy is required for culturing. Further, in the method of forcibly ventilating a gas containing carbon dioxide from the lower part of the culture tank, there is a problem that the photosynthetic organisms that have proliferated adhere to the vent tube and the vent tube is likely to be clogged, and high energy is required for venting.

The present invention has been made in view of the above circumstances, and in the culture of photosynthetic organisms, it is possible to efficiently supply light and carbon dioxide, and to reduce the energy required for culture. The purpose is to provide a culture device.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a liquid film forming plate for allowing a culture solution containing a photosynthetic organism to flow down in the form of a liquid film along the surface, and the solution. A culture apparatus for a photosynthetic organism, comprising a culture solution supply means for supplying a culture solution containing a photosynthetic organism to the upstream end of a film forming plate, and a light source for irradiating a liquid film on the liquid film forming plate with light, A light reflecting surface is provided around the liquid film forming plate, and an emission end of an optical fiber for propagating light from the light source is arranged between the liquid film forming plate and the light reflecting surface. Further, in the invention according to claim 2, the liquid film forming plate is made of a transparent plate material, and a light reflecting surface is provided on the lower surface side of the liquid film forming plate with a gap between the liquid film forming plate and the light reflecting surface. The emission end of an optical fiber that propagates the light from the light source is arranged in the gap. Further, in the invention according to claim 3, the liquid film forming plate is made of a transparent plate material, and light reflecting surfaces are provided on the lower surface side and the upper surface side of the liquid film forming plate with a gap therebetween, respectively, and The emission end of the optical fiber for propagating the light from the light source is arranged in the gap between either one or both of the light reflecting surfaces. Further, in the invention according to claim 4, the liquid film forming plate is provided with a light reflecting surface, and a light reflecting surface is provided on the upper surface side of the liquid film forming plate with a gap, and the liquid film forming plate and the light reflecting surface are provided. The emission end of an optical fiber that propagates the light from the light source is arranged in the gap with the surface. Furthermore, the invention according to claim 5 is the apparatus for culturing a photosynthetic organism according to claim 1, 2, 3 or 4, wherein a plurality of liquid film forming plates are provided.
The plates are laminated so that the upstream end of each plate is adjacent to the downstream end of the upper plate and the downstream end is adjacent to the upstream end of the lower plate.

[0007]

The apparatus for culturing photosynthetic organisms of the present invention forms a liquid film of a culture solution containing photosynthetic organisms on a liquid film forming plate, and the light from the light source and the dioxide from the surrounding gas phase are formed in the liquid film. It is used to cultivate photosynthetic organisms by supplying it while supplying carbon, and the thickness of the liquid film to be formed can be easily controlled by appropriately adjusting the flow rate of the culture liquid and the inclination angle of the liquid film forming plate. be able to. When culturing photosynthetic organisms in this liquid film, it is possible to irradiate light in the thickness direction of the liquid film because the liquid film is thin. By doing so, the contact area with the gas phase increases, and the carbon dioxide contained in the surrounding gas phase is easily taken into the liquid film. Further, a light reflecting surface is provided around the liquid film forming plate, and an emission end of an optical fiber for propagating the light from the light source is arranged between the liquid film forming plate and the light reflecting surface. Thus, the light from the light source can be uniformly applied to the liquid film on the liquid film forming plate with low loss, and the light utilization efficiency can be improved.

[0008]

1 and 2 are views showing a first embodiment of a culturing apparatus for photosynthetic organisms according to the present invention.
Is a culture section in which a plurality of liquid film forming plates 2 are stacked and arranged so that the upstream end of each plate 2 is adjacent to the downstream end of the upper plate 2 and the downstream end is adjacent to the upstream end of the lower plate 2. 3 and this culture section 3
A culture solution supply means 5 for supplying a culture solution 4 containing a photosynthetic organism to the upper end portion of the, a light source 7 for irradiating a liquid film 6 formed on the culture section 3 with light, and a container 8 for accommodating the culture section 3. And a gas supply means 10 for supplying a gas containing air or carbon dioxide into the container 8 from a gas supply port 9 provided in the container 8.
And is configured.

Each liquid film forming plate 2 of the culture section 3
Are arranged with an inclination of 30 degrees or less, preferably about 5 to 15 degrees. Even when the liquid film forming plate 2 is almost horizontal, when the culture solution 4 is supplied, the culture solution 4 can be caused to flow down by the supply pressure. The number of stacked layers of the liquid film forming plate 2 in the culture section 3 is not particularly limited, and may be one or more.

The culture solution supply means 5 is a culture solution adjusting tank 1
1, a liquid feed line 12 extending from the culture liquid adjusting tank 11 to the vicinity of the upstream end of the liquid film forming plate 3 through the upper portion of the container 8, a liquid feed pump 13 interposed in the liquid feed line 12, and a bottom portion of the container 8. And a recovery line 15 that connects the liquid discharge port 14 provided to the culture solution adjusting tank 11 and the liquid supply line 12 for supplying the culture solution 4 containing the photosynthetic organisms in the culture solution adjusting tank 11.
It is configured to be pressure-fed by the liquid feed pump 13 through the liquid feed line 12 and to be supplied from the liquid feed unit 16 at the end of the liquid feed line 12 to the upstream end of the culture unit 3 at a predetermined flow rate. The supply flow rate of the culture solution 4 can be easily adjusted by the liquid delivery pump 13, and the supply flow rate is appropriately set depending on the area of the culture section 3, the inclination degree of the liquid film forming plate 2, and the like. For example, a flat plate 2 of about 1 m ² is inclined 5 to 10
When a liquid film having a thickness of about 1 mm to 5 mm is formed on the surface of the culture solution 4, the culture solution 4 is 50 liter · h ^−1.
It is desirable to supply at a flow rate of about 500 liter · h ⁻¹ .

The culture line adjusting tank 11 has a harvest line 1
A harvesting device 18 is connected via 7 and a part of the culture solution 4 flowing down through the recovery line 15 is sent to the harvesting device 18 to separate (harvest) photosynthetic organisms in the culture solution 4. . As the harvesting device 18, a filtering tank, a precipitation tank, a centrifugal tank, or the like is used according to the size of the photosynthetic organism. The culture solution from which the photosynthetic organism has been separated may be returned to the culture solution adjusting tank 11 through another line. The temperature of the culture solution 4 is adjusted by installing a heat exchanger, a heater, a freezer, or the like from the culture section 3 to all or part of the culture solution supply means 5. The culture temperature is adjusted to a temperature suitable for culturing the target organism. The shape of the liquid supply part 16 for supplying the culture solution 4 containing the photosynthetic organisms to the upstream end of the culture part 3 is selected from among a single pipe, a branch pipe, a manifold, etc., having dispersibility, adhesion, and stress resistance of the organisms. Select in consideration of each property.

The light source 7 is composed of a xenon lamp 19 and a light guide 20 for guiding and irradiating this light to the upstream end of each liquid film forming plate 2. The light guide 20 is formed by bundling a large number of optical fibers.

The gas supply means 10 for supplying gas into the container 8 is a gas supply port 9 at the bottom of the container 8 for supplying exhaust gas containing air or carbon dioxide, etc. through the gas supply line 10a.
Is supplied at a predetermined flow rate. The exhaust gas used here is one from which harmful components such as sulfur oxides and hydrogen chloride gas have been removed in advance, and LNG combustion exhaust gas containing a small amount of these harmful components is preferable. The gas supplied into the container 8 is released to the outside from the gas discharge port 21 at the upper end of the container 8. The released gas is returned to the gas supply means 10 through the gas return line 22 as needed. It is also possible to circulate.

FIG. 3 shows the details of the liquid film forming plate 2 used in the culture apparatus 1 according to the first embodiment.
The liquid film forming plate 2 is made of a transparent plate material such as a glass plate or a transparent plastic plate, and is provided with a main body 23 on the upper surface side of which a liquid film 6 is formed and a space 24 on the lower surface side of the main body 23. And a frame 26 for fixing the main body 23 and the light reflecting plate 25. The light reflecting plate 25 is made of a plate material having a high reflectance such as a metal plate or a mirror plate, and a frame 26 for fixing the main body 23 and the light reflecting plate 25. In the space 24, the ends of a large number of optical fibers 27 from the light guide 20 are inserted into the end of the liquid film 6 on the upstream side in the downstream direction in a substantially lined state. The light from the xenon lamp 19 is emitted from the emission end 28 of each optical fiber 27 arranged in a line in the downward direction of the liquid film 6 and directly or reflected by the light reflection plate 25 to hit the lower surface of the main body 23. , The liquid film 6 on the upper surface side through the body 23
It is designed to illuminate this light. In addition, the frame 26
It is desirable that at least the surface of the portion facing the space 26 is also formed into a mirror surface having a high reflectance, whereby the loss of light can be further reduced. Further, the frame 26 is extended to both sides of the upper surface of the main body 23,
The culture solution 4 of the liquid film 6 is prevented from falling from the side.

A method for culturing a photosynthetic organism using the culturing apparatus 1 thus constructed will be described. As photosynthetic organisms to be cultured, in addition to freshwater and seawater algae such as chlorella, spirulina, diatoms, and lanceolates, various organisms such as photosynthetic bacteria and plant cells can be appropriately selected according to the purpose of use. Can be used. The culture medium for culturing these organisms is not particularly limited, and a commercially available culture medium or a prepared culture medium containing elements necessary for the growth of the organism (nitrogen, phosphoric acid, potassium, and other essential elements) Can be used.

Then, the above photosynthetic organisms are mixed with the culture solution 4 and placed in the culture solution adjusting tank 11, the solution feeding pump 13 is driven, and the culture solution 4 is fed through the solution feeding line 12 to the culture section 3.
Is supplied from the upstream end of the liquid film and is made to flow down in the form of a liquid film, and the light source 7 guides light to each liquid film forming plate 2 to irradiate the liquid film 6 with light from the lower surface side of the main body 23 of the liquid film forming plate 2. Further, a gas containing air or carbon dioxide is supplied into the container 8 from the gas supply port 9. The photosynthetic organisms contained in the culture solution 4 supplied onto the liquid film forming plate 2 receive light energy from the light source 7 while sequentially flowing down the liquid film forming plate 2, and the gas phase inside the container 8 is received. It grows while performing photosynthesis using carbon dioxide in the medium and water in the culture medium as raw materials. The liquid film 6 of this culture solution 4 is 1
Since it is as thin as about 5 mm, it is possible to irradiate light in the thickness direction of the liquid film, and by allowing the culture solution to flow down in the form of a liquid film, the contact area with the gas phase increases, Carbon dioxide contained in the surrounding gas phase is easily taken into the liquid film.

The culture solution 4 flowing down to the downstream end of the liquid film forming plate 2 at the lowermost stage of the culture section 3 has a liquid outlet 14 at the bottom of the container 8.
To the outside, and enters the culture solution adjusting tank 11 through the recovery line 15. And this culture solution 4 is a liquid transfer line 1
It is supplied again to the upstream end of the liquid film forming plate 2 at the uppermost stage of the culturing section 3 through 2 and is circulated to continuously cultivate the photosynthetic organism. When the concentration of the photosynthetic organism in the culture solution 4 has increased to a certain extent, a part of the culture solution in the culture solution adjusting tank 11 is sent to the harvesting device 18 through the harvesting line 17, and the culture solution 4
The photosynthetic organisms in the medium are collected, and a newly prepared culture liquid or a culture liquid in which the photosynthetic organisms are separated is used as a culture liquid adjusting tank 1
1 and replenish the culture solution 4.

This culture apparatus 1 forms a liquid film 6 of a culture solution 4 containing a photosynthetic organism on a liquid film forming plate 2, and in this liquid film 6 light from a light source 7 and from the surrounding gas phase are formed. The photosynthetic organism is cultivated by flowing it while supplying carbon dioxide, and the thickness of the liquid film 6 formed by appropriately adjusting the flow rate of the culture liquid 4 and the inclination angle of the liquid film forming plate 2. It can be controlled easily. When culturing a photosynthetic organism in the liquid film 6 as described above, since the liquid film is thin, it is possible to irradiate light in the entire thickness direction of the liquid film. Since the contact area with the gas phase is increased by letting it flow down in the form of a gas and carbon dioxide contained in the surrounding gas phase can be easily taken into the liquid film, stirring of the culture solution 4 can be omitted, Moreover, the supply efficiency of light and carbon dioxide is improved, and the culture efficiency per installation area can be significantly improved. Further, since the stirring of the culture solution 4 can be omitted, it is possible to eliminate the inconvenience that the photosynthetic organisms are damaged by the stirring, and further it is possible to reduce the energy required for operation. Further, the main body 23 of the liquid film forming plate 2
Is a transparent plate, and the light reflecting plate 25 is provided on the lower surface side of the main body 23.
And the light source 7 is provided between the main body 23 and the light reflection plate 25.
By arranging the emission end 28 of the optical fiber 27 for propagating the light from the light source 7, the light from the light source 7 can be uniformly applied to the liquid film 6 on the liquid film forming plate 2 with low loss, The light utilization efficiency can be improved.

FIG. 4 shows a second embodiment of the culture apparatus of the present invention. The difference between this embodiment and the first embodiment is only the lower surface side of the main body 23 of the liquid film forming plate 2. Instead, the light reflecting plate 29 is provided on the upper surface side with a space from the upper surface of the main body 23. The upper light reflecting plate 29 is provided with an end portion on the upstream side in the liquid film downward direction at a predetermined interval from the upstream end of the main body 23, and the culture solution 4 flows down to the surface of the main body 23 from this interval. Has become. This liquid film forming plate 2
The main body 23 of the liquid film forming plate 2 is a transparent plate material, light reflecting plates 25 and 29 are provided on both the lower surface side and the upper surface side of the main body 23, and a light source is provided between the main body 23 and the light reflecting plate 25. By arranging the emission end 28 of the optical fiber 27 for propagating the light from the light source 7, the light from the light source 7 can be uniformly applied to the liquid film 6 on the liquid film forming plate 2 with low loss. The light utilization efficiency can be further increased as compared with the liquid film forming plate 2 shown in FIG.

FIG. 5 shows a third embodiment of the culture apparatus of the present invention. In this embodiment, the liquid film forming plate 2 is used as the light reflecting plate 30 and the liquid film 6 is formed on the upper surface thereof. A light reflection plate 31 is provided on the upper surface side with a space,
The emission end 28 of the optical fiber 27 is arranged between the light reflection plates 30 and 31 on the side of the liquid film 6 in the downflow direction. According to this liquid film forming plate 2, it is possible to uniformly irradiate the liquid film 6 on the liquid film forming plate 2 with light from the light source 7 with a low loss, and further than the liquid film forming plate 2 shown in FIG. The light utilization efficiency can be improved.

In each of the above-described embodiments, the emission end 28 of the optical fiber 27 is arranged on the upstream side or the lateral side of the liquid film 6 in the downward direction, but the optical fiber 27 is arranged in two or more directions. It is also possible to arrange the emission end 28 of the above to irradiate the liquid film 6 with light.

(Experimental Example) A liquid film forming plate having the structure shown in FIG. 3 was prepared and the light energy distribution of emitted light was measured. Side 5
A 0 cm square glass plate is used as the liquid film forming plate body 23,
A stainless steel plate serving as the light reflection plate 25 is formed on the lower surface of the stainless steel plate 10
The pieces were arranged in parallel at an interval of mm and fixed to the frame body. on the other hand,
Light is guided from a xenon lamp light source by a light guide having 1600 optical fibers, and the emission ends of the optical fibers are arranged in a line between a glass plate and a stainless steel plate to form the liquid film forming plate shown in FIG. It was made. Then, the light energy distribution of the emitted light on the opposite side from the optical fiber emission end side on the upper surface of the glass plate was measured along the center line. The result is shown in FIG. As shown in FIG. 6, the light energy distribution along the center line of the liquid film forming plate is particularly large near the exit end of the optical fiber on the incident side, but it can be seen that the light energy is uniform as a whole.

[0023]

As described above, the apparatus for cultivating photosynthetic organisms according to the present invention forms a liquid film of a culture solution containing photosynthetic organisms on a liquid film forming plate, and a light from a light source is formed in the liquid film. Carbon dioxide from the surrounding gas phase is supplied while flowing down to cultivate a photosynthetic organism, and a liquid film formed by appropriately adjusting the flow rate of the culture solution and the inclination angle of the liquid film forming plate. The thickness of can be easily controlled.
When culturing a photosynthetic organism in a liquid film in this way, it is possible to irradiate light in the entire thickness direction of the liquid film because the liquid film is thin. The contact area with the gas phase is increased by letting the solution flow down, and the carbon dioxide contained in the surrounding gas phase can be easily taken into the liquid film, so that the stirring of the culture solution can be omitted and the Also, the supply efficiency of carbon dioxide is improved, and the culture efficiency per installation area can be significantly improved. Further, since the stirring of the culture solution can be omitted, it is possible to eliminate the inconvenience that the photosynthetic organisms are damaged by stirring, and it is possible to reduce the energy required for operation. Further, a light reflecting surface is provided around the liquid film forming plate, and an emission end of an optical fiber for propagating the light from the light source is arranged between the liquid film forming plate and the light reflecting surface. Thus, the light from the light source can be uniformly applied to the liquid film on the liquid film forming plate with low loss, and the light utilization efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a culture apparatus for photosynthetic organisms of the present invention.

FIG. 2 is a perspective view showing a partial cross-section of a main part of the same culture apparatus.

FIG. 3 is a perspective view showing a liquid film forming plate of the same culture apparatus.

FIG. 4 is a perspective view showing a liquid film forming plate of a second embodiment of the culture apparatus of the present invention.

FIG. 5 is a perspective view showing a liquid film forming plate of a third embodiment of the culture apparatus of the present invention.

FIG. 6 is a graph showing a light energy distribution showing the results of an experimental example according to the present invention.

[Explanation of symbols]

1 ... Incubator, 2 ... Liquid film forming plate, 3 ... Incubator, 4
...... Culture fluid, 5 ...... Culture fluid supply means, 6 ...... Liquid film, 7 ...
... light source, 8 ... container, 9 ... gas supply port, 10 ... gas supply means, 11 ... culture solution adjusting tank, 12 ... liquid supply line, 13 ... liquid supply pump, 14 ... liquid discharge port , 15 ……
Recovery line, 16 ... Liquid supply unit, 18 ... Harvesting device, 1
9 ... Xenon lamp, 20 ... Light guide, 21 ... Gas outlet, 22 ... Gas return line, 23 ... Liquid film forming plate body, 24 ... Space, 25, 31 ... Light reflecting plate, Two
6 ... frame, 27 ... optical fiber, 28 ... emission end, 3
0: Light reflection plate (liquid film forming plate body).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Oniyama 2-8-11 Nishishimbashi, Minato-ku, Tokyo Inside the Institute for Global Environmental Technology

Claims (5)

[Claims] 1. A liquid film forming plate for causing a culture liquid containing a photosynthetic organism to flow down in a liquid film shape along a surface, and a culture liquid supplying means for supplying a culture liquid containing a photosynthetic organism to the upstream end of the liquid film forming plate. And a light source for irradiating a liquid film on the liquid film forming plate with a light source, wherein the liquid film forming plate is provided with a light reflecting surface around the liquid film forming plate. A photoincubator for culturing a photosynthetic organism, wherein an emitting end of an optical fiber for propagating the light from the light source is arranged between the light reflecting surface and the light reflecting surface. 2. The liquid film forming plate is made of a transparent plate material, a light reflecting surface is provided on the lower surface side of the liquid film forming plate with a gap, and a light source is provided in the gap between the liquid film forming plate and the light reflecting surface. The photosynthetic organism culturing apparatus according to claim 1, wherein an emitting end of an optical fiber for propagating the light is disposed. 3. The liquid film forming plate is made of a transparent plate material, and a light reflecting surface is provided on each of a lower surface side and an upper surface side of the liquid film forming plate with a gap between the liquid film forming plate and the upper and lower light reflecting surfaces. The photosynthetic organism culture apparatus according to claim 1, wherein an emission end of an optical fiber for propagating light from the light source is arranged in one or both of the gaps. 4. The liquid film forming plate is provided with a light reflecting surface, the light reflecting surface is provided on the upper surface side of the liquid film forming plate with a gap, and in the gap between the liquid film forming plate and the light reflecting surface. The culturing device for photosynthetic organisms according to claim 1, wherein an emitting end of an optical fiber for propagating light from the light source is arranged. 5. The apparatus for culturing a photosynthetic organism according to claim 1, 2, 3 or 4, wherein a plurality of liquid film forming plates have an upstream end of each plate adjacent to a downstream end of an upper plate and a downstream end thereof. A culturing device for photosynthetic organisms, wherein the culturing device for photosynthetic organisms is arranged so as to be adjacent to the upstream end of the lower plate.