JP3132722B2 - Solar energy induction / diffusion type photobioreactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar energy induction / diffusion type photobioreactor, and more particularly, to a photobioreactor or the like in which a biophotochemical reaction is caused by solar radiation so that the total energy of the solar radiation can be utilized while diluting the intensity of the solar radiation. The present invention relates to a photovoltaic reactor for solar energy induction and diffusion.

[0002]

2. Description of the Related Art Irradiation of living organisms such as microorganisms with sunlight or artificial light to cause a photochemical reaction in living organisms to obtain a reaction product thereof, or removal or denaturation of a specific target substance by the reaction. It is attracting attention in biotechnology and the like. At present, attempts have been made to produce spirulina and carotene by a technique utilizing the photochemical action of microorganisms. There has also been proposed a photochemical bioreactor in which an optical fiber is combined with a light emitting plate or a light emitting body.

[0003]

However, these attempts or proposals have not yet been satisfactory in terms of cost and efficiency. For example, the energy conversion efficiency in the case of generating hydrogen by irradiating solar energy using the photochemical reaction of living organisms is given as (heat of combustion of generated hydrogen / incident solar energy). Not so high. With these photochemical reaction utilizing technologies, it is not always easy to obtain a sufficient amount of generated light within a limited period when the light source is the sun, and in the case of an artificial light source, the cost for driving the artificial light source increases. Problems have been pointed out.

As a result of studying the improvement of energy conversion efficiency in photochemical reactions of living organisms, the present inventor paid attention to the intensity of incident light. The energy conversion efficiency is maximized at a certain constant value of the intensity of incident light per unit area on the light receiving surface of the reaction solution (hereinafter referred to as "effective light receiving intensity"), and the energy conversion efficiency is increased when the intensity of incident light is further increased. If it decreases, it is effective to lower the effective received light intensity to the fixed value, that is, dilute the intensity, to improve the energy conversion efficiency. In a photobioreactor, if light incident from an incident surface having a certain area is irradiated to a reaction chamber through a light emitting surface having an area larger than the certain area,
The light intensity on the incident surface is diluted, and the effective light receiving intensity in the reaction chamber becomes lower than the incident light intensity on the light receiving surface. In this case, light incident on the photobioreactor can be used in the reaction chamber with no or low loss, and improvement in energy conversion efficiency can be expected.

[0005] Accordingly, an object of the present invention is to make incident light transparent.
It is an object of the present invention to provide a photobioreactor that is used after being diluted with a material diffusion plate .

[0006]

As a means for reducing the effective received light intensity, the present inventors have focused on a backlight plate attached to a computer display. In this backlight plate, light is incident from a narrow light incident surface and light is uniformly emitted from a wide light exit surface. In the present invention, a light diffusing element having a light emitting surface having a larger area than the light incident surface is interposed between the light incident surface of the photobioreactor and the reaction chamber in which the reactant is loaded. This dilutes the intensity of the incident light and emits it to the reaction chamber to improve the light energy utilization efficiency.

In the embodiment shown in FIG. 1, a solar photovoltaic / biodiffusion type photobioreactor 10 according to the present invention is provided with solar radiation.
The light diffusion element 1 is used as a reaction chamber for the photobioreactor 10
12 and light receiving surface 4 at the top and reaction chamber
Extend at least as deep as the reaction chamber 12 in the depth direction of 12
Light from the upright diffusing surface 5 and the light receiving surface 4 is reflected to the diffusing surface 5
Surface and a wide light exit surface for emitting diffused light from the diffusion surface 5
6 with the diffusing surface 5
The pair connected back to back is referred to as a light diffusion element 1 and each diffusion plate
A light diffusing surface 5 for reflecting the light from the narrow light receiving surface 4
Then, the light is reflected to the reaction chamber 12 via the light emitting surface 6 which is diffused by the diffusion surface 5 and is wide. Preferably, the light diffusing element 1 and the reaction chamber 12 are provided in the tank 11.

Referring to FIG. 2, the light diffusing element 1 preferably has a narrow light receiving surface 4, a wide light emitting surface 6, and a diffusing surface 5 for diffusing incident light on the light receiving surface 4 toward the light emitting surface 6. A pair of diffusion plates 3 made of a translucent material, and a reflection plate 2 held between the pair of diffusion plates 3 back-to-back with the diffusion surface 5
It is constituted by. In the example of FIG. 2A, each diffusion plate 3 is a quadrilateral having a diffusion surface 5 and a light exit surface 6 perpendicular to the light receiving surface 4, respectively, and a pair of quadrilateral diffusion plates 3 is formed by the reflection plate 2. 5 to form a substantially rectangular outer shape of the light diffusing element 1, and more preferably, a point angle θ between the terminal surface 7 and the diffusing surface 5 of each diffusing plate 3 that faces the light receiving surface 4 is 75 °. ~ 6
0 °.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIG. 1, a light diffusing element 1 is formed by a diffusing plate 3 having a triangular cross-sectional structure in which a light receiving surface 4 and a diffusing surface 5 are perpendicular to each other. The length is equal to the length of the tank 11, the narrow light receiving surface 4 of each of the plurality of diffusion plates 3 is arranged along the top surface of the tank 11, and the diffusion surface 5 is set in the depth direction of the tank 11. Plug-in, adjacent light diffusion element 1
A reaction chamber 12 is formed between the light emitting surfaces 6 of the light emitting elements. The reaction chamber 12 is filled with a reaction solution 13 such as a cell fluid. Diffusing plate 3
Is a transparent member made of a transparent material such as methyl methacrylate (MMA) resin or glass. Both the light receiving surface 4 and the light emitting surface 6 have a length equal to the length of the tank body 11,
The light-receiving surface 4 has a small area because the width is narrow, and the light-emitting surface 6 has a tank body 11.
Can be larger than the depth of the light receiving surface 4, and the width of the light emitting surface 6 is wider than the area of the light receiving surface 4. Further, the light diffusing element 1 of this embodiment is one in which the diffusing surfaces 5 of the pair of diffusing plates 3 are joined back to back by the reflecting plate 2, but the light diffusing element 1 is formed by a single diffusing plate 3. Is also good. In order to ensure the diffusion of light, preferably, a large number of dots are printed on the diffusion surface 5, and diffuse reflection at those dots is used for diffusion. The dotted lines on the diffusion surfaces 5 in FIGS. 1 and 2 indicate that this dot print is on those diffusion surfaces 5.

In the light diffusing element 1 shown in FIG. 1B comprising a pair of right-angled triangular diffusing plates 3, incident light from the light receiving surface 4 toward the lower end of the diffusing surface 5 is diffused by the diffusing surface 5. It is necessary to avoid unevenness in the intensity of light entering the reaction chamber 12 by emitting light from the light emitting surface 6 without any problem. For this reason, the light that directly reaches the light emitting surface 6 from the light receiving surface 4 without passing through the diffusing surface 5 is totally reflected as much as possible and directed to the diffusing surface 5, so that the apex angle γ of the wedge-shaped tip is made acute. The apex angle γ of the wedge-shaped light diffusing element 1 should not be too sharp for handling. In consideration of these points, it has been found that an appropriate value of the wedge-shaped apex angle γ in FIG. 2B is 20 ° to 30 °. However, the light diffusing element 1 of the present invention is not limited to this wedge-shaped one.

The incident light I from above the photobioreactor 10 shown in FIG. 1 passes through the light receiving surface 4 of the light diffusing element 1 and travels to the lower end of the diffusing surface 5, while being diffused from the entire surface of the diffusing surface 5. The light is directed toward the light emitting surface 6 and enters the reaction chamber 12. Since the entire amount of the incident light I enters the reaction chamber 12, the light intensity on the light receiving surface 4 is reduced outside the light emitting surface 6 at a ratio of (area of light receiving surface 4 / area of light emitting surface 6). That is, the total amount of the incident light I is diluted and the reaction chamber
Supplied to 12. For example, when the optimal input light intensity of a certain photochemical reaction X is lower than the intensity of direct sunlight, even if direct sunlight is added to the photochemical reaction X system as it is, the intensity portion exceeding the optimal input light intensity is not fully utilized, It is a part of the direct sunlight energy that is effectively used, and the energy conversion efficiency has to be relatively low. According to the solar energy induction / diffusion photobioreactor of the present invention, it is possible to dilute the intensity of incident light at a ratio of (area of light receiving surface 4 / area of light emitting surface 6), including the case of direct sunlight. Therefore, the total amount of the received direct sunlight energy is diluted to an input light intensity less than the intensity of the direct sunlight, for example, the optimal input light intensity for the photochemical reaction X, and then added to the photochemical reaction X system, and the energy conversion efficiency and the biophotochemical reaction are added. Efficiency can be improved.

[0012] Therefore, is the object "incident light of the present invention, Toru
The provision of a photobioreactor that is used after being diluted with a light-emitting material diffusion plate is achieved.

[0013]

In the embodiment of FIG. 3, each diffusing plate 3 is a quadrilateral having a diffusing surface 5 and a light emitting surface 6 perpendicular to the light receiving surface 4, and a pair of quadrilateral diffusing plates 3 is formed by the reflecting plate 2. The light diffusing element 1 having a substantially rectangular outer shape joined back to back by the diffusing surface 5 is used.

In many cases, the diffusion plate 3 is preferably a relatively thick transparent plate from the viewpoint of easy handling. In this case, if the terminal surface 7 facing the light receiving surface 4 is made transparent, most of the light received on the light receiving surface 4 escapes from the terminal surface 7 without being substantially subjected to intensity dilution. The rate of light emission from the light emitting surface 6 with respect to the amount of light received on the surface 4 decreases, and the efficiency of the photochemical reaction decreases. In order to avoid this decrease in the light output rate, a mirror surface member 8 such as an aluminum foil shown in FIG. 2A is attached to the terminal surface 7 or another suitable reflective material is applied to the terminal surface 7 so as to reach the terminal surface 7. All the reflected light is reflected inside the diffusion plate 3. In addition, if the reflected light is directed to the light receiving surface 4, the reflected light escapes from the light receiving surface 4. For this reason, it is preferable that the point angle θ between the diffusion surface 5 and the terminal surface 7 shown in FIG. This angle θ is
When the angle exceeds 75 °, the amount of reflected light that escapes from the light receiving surface 4 increases, and the light output rate from the light emitting surface 6 decreases. Becomes too small and the light reflected from the terminal surface 7 is not diffused and the light exit surface 6
The light exiting from the light exit surface 6 becomes more uniform, and the uniformity of the light exit from the light exit surface 6 deteriorates. However, the diffusion plate 3 of the present invention is not limited to a flat plate or a plate with the mirror member 8.

When comparing the photobioreactor 10 shown in FIGS. 1 and 3, in the case of FIG. 1, the intensity dilution is performed for all of the incident light I, but in the case of FIG. The light directly incident on the reaction chamber 12 is not subjected to the intensity dilution according to the present invention. On the other hand, when the size of the tank body 11 is made equal, the structure of FIG. 3 can put the reaction solution 13 in the photobioreactor 10 twice as much as the structure of FIG. Reaction liquid 13
The amount will increase. In FIG. 3, the operation of the conventional flat photobioreactor can be expected also for the direct incident light I that does not pass through the light diffusion element 1.

In the embodiment of FIG. 4, a translucent mirror 9 is attached to the terminal surface 7 of the light diffusion element 1 used in the photobioreactor 10 of FIG.
Light is transmitted through the semitransparent mirror 9 to the lower end communication portion 14 of the reaction chamber 13 formed by making the depth 11 deep as shown by a downward arrow D.

It should be noted here that the light diffusion element 1 of the solar energy induction / diffusion type photobioreactor 10 according to the present invention not only diffuses light to dilute the intensity but also makes the reaction liquid 13 transparent. Is low and the light does not reach the deep part of the photobioreactor 10 through the reaction solution 13, the light is transmitted to the photobioreactor 10 by the transparent diffusion plate 3.
It also acts as a light guide to reach the bottom or depth of 10. This light guiding action contributes to the improvement of the reaction rate per unit floor area of the photobioreactor 10, and also has the effect of improving productivity. Moreover, the light loss in the light diffusing element 1 is small, and can be assumed to be 10% or less. Depending on the photochemical reaction performed in the reaction chamber 12, the productivity per unit floor area of the photobioreactor can be reduced by the solar energy induction / diffusion photobioreactor 10 of the present invention as compared with the conventional flat plate type photobioreactor. It is expected that it can be improved twice.

The size of the solar energy induction / diffusion type photobioreactor 10 is determined by the nature and amount of the reaction solution 13 to be treated and other design conditions, but the depth is about 1 meter, and the width and length are several meters. From several meters to several tens of meters will be practical. However, it is not limited to these numerical values.

[0019]

As described above, the solar energy induction / diffusion type photobioreactor of the present invention uses the entire amount of incident light energy for the photochemical reaction while diluting the intensity of the incident light. To play.

(A) By using the total energy of incident light such as direct sunlight with extremely high intensity while diluting the intensity, the incident light can be used at an optimum level of light intensity without waste and processed with the same incident light energy. The amount of reactants available can be increased. (B) Even in the case of a deep photobioreactor, the incident light can be guided to the deep part of the photobioreactor with low loss, so that the throughput per unit floor area is increased and a photobioreactor with a high processing capacity is provided. Can be. (C) It is possible to assemble an optimal photochemical reaction device according to the operating environment by appropriately combining with a conventional flat plate photobioreactor.

(D) It can be made of inexpensive materials such as a diffusion plate made of a transparent resin or glass and a metal reflection plate. (E) For example, in a reaction system utilizing the photochemical action of microorganisms, such as a technique for converting sunlight energy to hydrogen gas by photochemical reaction of microorganisms, the amount of light energy that can be processed by a unit amount of microorganisms is relatively small. In addition, when there is a limit to the concentration of microorganisms in the processing solution, there is a problem how to efficiently introduce high-intensity or high-density incident energy such as direct sunlight into the photochemical reaction system of microorganisms. A photobioreactor capable of intense dilution is expected to be effectively used for such a microbial photochemical reaction system.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the structure of a light diffusion element.

FIG. 3 is an explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory view showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light diffusion element 2 ... Reflection plate 3 ... Diffusion plate 4 ... Light receiving surface 5 ... Diffusion surface 6 ... Light emission surface 7 ... Termination surface 8 ... Mirror surface member 9 ... Translucent mirror 10 ... Photobioreactor 11 ... Tank body 12 ... Reaction Chamber 13: Reaction liquid 14: Lower end communicating part.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shozo Kawasaki 2-8-11 Nishi-Shimbashi, Minato-ku, Tokyo The Institute for Research on Global Environment, Industrial Technology Incorporated Project Room, etc. (72) Inventor Leda M. A-L-Shishitawi 2-81, Nishi-Shimbashi, Minato-ku, Tokyo Office of the Research Institute for Innovative Technology for the Earth, CO2 Fixation Project Room (72) Inventor Yoshiyuki Ueno 2--8, Nishi-Shimbashi, Minato-ku, Tokyo No. 11 CO2 fixation project room, etc. (72) Inventor Nahoko Kunishi 2-8-11 Nishishinbashi, Minato-ku, Tokyo Project for CO2 fixation, National Institute for Global Environmental Technology Indoor (56) References JP-A-6-62694 (JP, A) JP-A-57-181689 ( P, A) Tokuoyake Akira 45-940 (JP, B1) (58 ) investigated the field (Int.Cl. ^7, DB name) C12M 1/00 - 3/10

Claims (11)

(57) [Claims] 1. A photobioreactor comprising a light diffusing element for solar light.
Provided in contact with the reaction chamber of the coater, narrow solar radiation receiving a respective top portion
At least the same depth as the reaction chamber in the depth direction between the light surface and the reaction chamber
Light from the upright diffusion surface and the light-receiving surface extending to the diffusion surface
Wide light output for emitting diffused light from the surface to be reflected and the diffused surface
And two diffusion plates made of a translucent material having
The light-diffusing element is a pair connected in a middle position, and is in front of each diffuser.
The light from the narrow light receiving surface is reflected by the surface to the diffusion surface.
A solar energy induction / diffusion type photobioreactor, which is reflected , diffused on a diffusion surface, and irradiated to the reaction chamber through the wide light exit surface. 2. The photobioreactor according to claim 1, wherein a large number of dots are printed on the diffusion surface of the light diffusion element, and the light is diffused by irregular reflection at the large number of dots. . 3. A photobioreactor according to claim 1, wherein each of said diffusion plates has a narrow light receiving surface and an upright diffusion surface.
A wide light exit surface facing the diffusion surface and facing the light receiving surface
A diffusion plate having a rectangular cross section by providing a terminal surface;
A solar energy induction / diffusion type photobioreactor that serves as a reflective surface . 4. The photobioreactor according to claim 3, wherein
The end surface facing the light receiving surface of each diffusion plate is a mirror surface member.
And reflects all the light that has reached the terminal surface into the diffuser.
Solar energy induction-diffusion type photobioreactor made Te. 5. The photobioreactor according to claim 4, wherein
The mirror member at the end face of each diffusion plate is made of aluminum.
A solar energy induction / diffusion photobioreactor formed by attaching a foil or applying a reflective material . 6. The photobioreactor according to claim 3, wherein
Through the non-diffused part of the light incident on the light diffusion element.
A semi-transparent mirror is provided in the part of the light exit surface
A solar energy induction / diffusion type photobioreactor wherein the chamber is also in contact with the translucent mirror . 7. The photobiore according to claim 4, wherein
In the actor, a terminal facing the light receiving surface of each of the diffusion plates.
Thick <br/> positive energy guiding and diffusion type photobioreactor that the tip angle θ made as 75 ° to 60 ° between the end face and the diffusion face. 8. The photobioreactor according to claim 1, wherein
Then, each diffusing plate of the light diffusing element is connected to a diffusing surface perpendicular to the light receiving surface.
Right-angled triangular cross-section including a diffusing surface and an inclined light emitting surface
And the two diffusers having a right triangle shape in cross section
A wedge-shaped diffuser pair with an acute angle γ
Then, the light from the light receiving surface is reflected by the inclined light emitting surface to the diffusion surface.
A solar energy induction / diffusion type photobioreactor. 9. The photobioreactor according to claim 8, wherein
Then, the diffusion surfaces of the respective diffusion plate pairs are back-to-back with the reflection plate.
Solar energy directing-diffusion type photobioreactor comprising bonded to. 10. The photobioreactor according to claim 8 or 9.
In chromatography, the apex angle γ of the wedge-shaped diffuser plate pair and 20 ° to 30 °
Solar energy induction-diffusion type photobioreactor made Te. 11. The photobioreactor according to claim 1, wherein
A solar energy induction / diffusion type photobioreactor comprising a light diffusion element and a reaction chamber provided in a tank body .