Fermentation tank device

Abstract

To provide a fermentation tank device for hydrogen production employing photosynthetic bacteria, which enables stable and efficient hydrogen generation with minimal influence from the strength of sunlight.SOLUTION: A fermentation tank device is provided, wherein a columnar culture vessel 14 and a control vessel 15 are arranged inside a housing 12 capable of transmitting visible light; the culture vessel 14 accommodates a decomposable substance containing photosynthetic bacteria and a member 19 serving as a bed for the photosynthetic bacteria; the control vessel includes at least a light-emitting lamp 25 for irradiating the culture vessel; and warm water for keeping the culture vessel within a predetermined temperature range flows inside the housing 12.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fermenter device using photosynthetic bacteria that produce hydrogen, and more particularly to a fermenter device in which the efficiency of hydrogen production by photosynthetic bacteria is improved to drive a fuel cell. [Background technology]

[0002] In recent years, hydrogen production technology using photosynthetic bacteria has made remarkable progress due to advances in research and development of photosynthetic bacteria. Hydrogen production using photosynthetic bacteria has many advantages, including not relying on fossil fuels and not requiring special fermentation equipment, as the hydrogen production reaction occurs at room temperature.

[0003] However, despite these advantages, the practical application of hydrogen production facilities using photosynthetic bacteria has not progressed. The main reason for this is the low efficiency of hydrogen production. Continuous exposure to light energy is essential for the growth of photosynthetic bacteria, and temperature control and a growth environment suitable for the growth of photosynthetic bacteria must be created.

[0004] For this reason, various efforts have been made to improve the efficiency of hydrogen production by photosynthetic bacteria. Non-Patent Document 1 discloses a reactor in which sunlight from a sunlight collector is guided by optical fiber to supply light energy to the bacteria. However, although this method allows light to be irradiated to the entire reactor through the optical fiber, it does not obtain sufficient light energy, and there is a problem that hydrogen production drops significantly not only at night when sunlight is unavailable, but also on cloudy or rainy days when sunlight is weak.

[0005] Patent Document 1 discloses a technique for covering a fermenter with a jacket and running cooling water through the jacket to keep the fermenter at a constant temperature. However, temperature control alone is not sufficient to increase the efficiency of hydrogen production in the fermenter. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2001-299327 [Non-patent literature]

[0007] [Non-Patent Document 1] Hydrogen Energy Systems Vol. 20, No. 1-2, 1995 "Hydrogen production by marine photosynthetic microorganisms" Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention solves these problems and provides a hydrogen-producing fermentation device using photosynthetic bacteria that can produce hydrogen steadily and efficiently without being affected as much as possible by the intensity of sunlight, making it suitable for use in fuel cells. [Means for solving the problem]

[0009] The fermentation tank apparatus of the present invention is characterized in that a cylindrical culture vessel and a control vessel are provided in a housing that is transparent to visible light, decomposition substances including photosynthetic bacteria are stored in the culture vessel, and a member that serves as a bacterial bed for the photosynthetic bacteria is installed in the culture vessel, a light-emitting lamp that illuminates at least the culture vessel is located in the control vessel, and warm water is flowing within the housing to maintain the culture vessel within a predetermined temperature range. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an exterior elevational view of a first embodiment of a fermenter apparatus according to the present invention. [Figure 2] FIG. 2 is a longitudinal sectional view of a first embodiment of a fermenter apparatus according to the present invention. [Figure 3] FIG. 3 is a cross-sectional view of the first embodiment of the fermenter apparatus according to the present invention taken along the line A-A' in FIG. [Figure 4]FIG. 4 is a cross-sectional view of the first embodiment of the fermenter apparatus according to the present invention taken along the line BB' of FIG. [Figure 5] FIG. 5 is a longitudinal sectional view of a second embodiment of a fermenter apparatus according to the present invention. [Figure 6] FIG. 6 is a cross-sectional view of a second embodiment of the fermenter apparatus according to the present invention taken along the CC' plane of FIG. [Figure 7] FIG. 7 is a cross-sectional view of a second embodiment of the fermenter apparatus according to the present invention taken along the line D-D' of FIG. [Figure 8] FIG. 8 is an exterior elevational view of a third embodiment of a fermenter apparatus according to the present invention. [Figure 9] FIG. 9 is a longitudinal sectional view of a third embodiment of a fermenter apparatus according to the present invention. [Figure 10] FIG. 10 is a cross-sectional view of the third embodiment of the fermenter apparatus according to the present invention taken along the line EE' of FIG. [Figure 11] FIG. 11 is an overall view of a domestic electric hot water supply system using a fermenter device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0011] A first embodiment of the fermenter apparatus according to the present invention will be described with reference to Figures 1 to 4. Figure 1 shows an exterior elevation view of a fermenter 1 according to the present invention, in which a cylindrical polycarbonate resin housing 12 is adhesively inserted into a metal dish-top base 11. A top plate 13 of housing 12 has holes formed concentrically at equal angles into which columnar acrylic resin culture vessels 14 are fitted.

[0012] In the first embodiment, six cylindrical culture vessels 14 with a diameter of 25 centimeters are installed, so the top plate 13 has six insertion openings spaced at 60 degree intervals and an insertion opening in the center of the top plate 13 through which a cylindrical control vessel 15 is inserted.

[0013] Three support columns 16 are attached to the base 11, and the base is supported at a predetermined distance (approximately 30 centimeters in this embodiment) from the ground. Furthermore, a pipe 17 that supplies hot water at a constant temperature into the housing 12 and a pipe 18 that drains the hot water are attached to the base 11, so that the hot water circulates within the housing to maintain a constant temperature inside the housing. The water supply pipe 17 passes through the base 11, passes through the control vessel, and reaches the top of the housing, from which the hot water is poured into the housing. The drain pipe 18 passes from the bottom of the housing through the control vessel, passes through the base 11, and drains the water to the outside.

[0014] This warm water is supplied by changing the mixture ratio of hot water from the hot water tank and cold water from the well based on the output of a sensor (not shown) that constantly monitors the temperature inside the culture vessel, so that the culture vessel maintains a constant temperature even if the outside air temperature changes.

[0015] The culture vessel 14 is cylindrical and completely sealed from the housing, and nylon mesh 19 is arranged inside the cylinder as a bacterial bed for photosynthetic bacteria to produce hydrogen. In the first embodiment, as shown in Figure 3, four acrylic pipes 24 are installed around the periphery of the vessel 14 and four in the center as supports, and nylon mesh 19 with a mesh size of approximately 100 μm is wrapped around the supports in a cross shape. The way in which nylon mesh 19 is stretched is not limited to this, and it can also be in a star shape, a cylinder shape, or a triangle shape.

[0016] Activated carbon 30 is spread over the bottom of the culture vessel 14 for the purposes of promoting the cultivation of photosynthetic bacteria and purifying the water. In this embodiment, the activated carbon layer is about 30 mm thick.

[0017] Cellulose material, serving as a decomposition material, is packed on top of the activated carbon in container 14, almost up to the height of the nylon mesh. In the present invention, finely shredded paper or sawdust is primarily used as the cellulose material. However, since no photosynthetic bacteria are known to have particularly high cellulose-decomposing abilities, bacteria of the genus Cellulomonas are first used to break down the cellulose into sugars. The sugars broken down from the cellulose are metabolized by photosynthetic bacteria such as purple non-sulfur bacteria, and the photosynthetic bacteria generate hydrogen as a result of this metabolism.

[0018] Since moisture is required to decompose cellulose materials, there is a water spray pipe 20 on the top of the nylon mesh 19 that connects to a water spray outlet for spraying water onto the cellulose materials.This water spray pipe 20 extends from the base 11 through the control container 15 to the top of the housing 12, and from there sprays water onto the tops of the six culture containers 14.

[0019] A drainage pipe 21 is provided at the bottom of the culture vessel 14 to drain the sprayed water, and the drainage pipes 21 from the six culture vessels pass through the base 11 and are connected to each other so that the water can be drained to the outside.

[0020] A space 28 is provided at the top of the culture vessel 14 to temporarily store the hydrogen that is produced in the fermenter and rises upward. As shown in Figure 4, the spaces 28 of each culture vessel 14 are connected by a hydrogen exhaust pipe 22, and as the hydrogen pressure increases, it is naturally supplied to the outside through the exhaust pipe 22.

[0021] An opening 29 is provided at the top of the culture vessel for maintenance of the photosynthetic bacteria and for replenishing cellulose material, and this opening 29 is closed with a sealing lid 23 .

[0022] As shown in Figures 2 and 3, six rod-shaped light-emitting lamps 25 are installed vertically inside the control vessel 15, facing the culture vessel 14. These light-emitting lamps 25 are turned on when there is no sunlight, such as on rainy or cloudy days, or at night, to promote the metabolism of the photosynthetic bacteria. Power is supplied to the light-emitting lamps 25 from a storage battery via a power line 27. Since it is known that photosynthetic bacteria are most active at red wavelengths in the sunlight spectrum, in the first embodiment, red lamps are used as the light-emitting lamps 25, and a red film 26 is attached to the outer periphery of the culture vessel. A red film may also be attached to the outer periphery of the housing 12.

[0023] In the first embodiment, the housing 12 is 100 cm in diameter and 95 cm in height and is made of polycarbonate resin, which has excellent impact resistance and transparency, and is also resistant to ultraviolet rays, making it suitable for housings used outdoors.

[0024] The culture vessel 14 is molded from acrylic resin with a diameter of 25 cm and a height of 110 cm. The culture vessel 14 can also be made from polycarbonate resin, but since it is used inside a housing and does not require as much impact resistance as the housing 12, in this example it is molded from cheaper acrylic resin.

[0025] In this embodiment, the housing 12, the culture vessel 14, and the control vessel 15 are molded separately and then combined, but they may be molded integrally from polycarbonate resin, which is easy to mold.

[0026] The housing 12 and the culture vessels 14 are not limited to being cylindrical, but may be polygonal pillars such as hexagonal pillars, and the number of culture vessels can be increased or decreased by changing the diameter. [Example]

[0027] A second embodiment of the fermenter according to the present invention will be described with reference to Figures 5 to 7. In this second embodiment, the number of culture vessels 14 installed in the housing 12 is four, and they are arranged at 90-degree intervals within the housing, but their structure and function are substantially identical to those of the culture vessels 12 in the first embodiment.

[0028] In the second embodiment, an electrolytic cell is provided inside the control vessel 15 as an auxiliary hydrogen generation device. The electrolytic cell consists of anode tubes 31, cathode tubes 32, and connecting tubes 33 connecting them, with four pairs of tubes provided, two of each pair intersecting. The anode tubes 31 are approximately 55 centimeters long and made of acrylic pipe with a diameter of approximately 5 centimeters. A yellow film is attached to the surface of the anode tube 31 pipe.

[0029] The cathode tube 32 is about 50 cm long and made of an acrylic pipe with a diameter of about 5 cm. A blue film is attached to the surface of the cathode tube 32.

[0030] The anode tubes 31 and cathode tubes 32 are connected in pairs at their bottoms by connecting tubes 33 with a diameter of approximately 3 centimeters. The anode tubes 31 and cathode tubes 32 are attached approximately in the upper half of the control vessel 15, and the upper end of the anode tube 31 is closed by a screw cap 34. An electrolyte such as an aqueous sodium hydroxide solution can be poured through this screw cap 34. The screw cap 34 also has an air hole that allows oxygen generated by the anode tube 31 to be released into the air.

[0031] A hydrogen transport pipe 35 is attached to the upper end of the cathode tube 32 to extract the hydrogen generated from the cathode tube 32, and the other end of the transport pipe 35 is connected to the hydrogen discharge pipe 22 so that the hydrogen can be combined with the hydrogen from the culture vessel.

[0032] A columnar storage battery 36 is installed in the lower half of the control vessel 15, below the anode tube 31 and the cathode tube 32, to supply power to the electrodes (not shown) provided inside the anode tube and the cathode tube, respectively.

[0033] This allows the electrolysis tank to be operated when the amount of hydrogen supplied from the culture vessel 12 is low, such as during bad weather or at night, to generate hydrogen from the cathode tube 32 and supplement the amount of hydrogen sent to the fuel cell. [Example]

[0034] A third embodiment of the fermenter according to the present invention will be described with reference to Figures 8 to 10. Figure 8 shows an exterior elevation view of the culture tank of the third embodiment. The housing 12 is cylindrical and made of transparent acrylic or polycarbonate resin, allowing sufficient sunlight to reach the culture vessel 14 and promote the growth of photosynthetic bacteria.

[0035] In this third embodiment, the culture vessel 14 is configured as one large cylinder, and therefore one sealing lid 23 for the culture vessel 14 is provided at the top center of the housing 12. The culture vessel 14 in this embodiment is donut-shaped, with a hole 41 formed in its center into which the control vessel 15 is inserted. The control vessel 15 is placed in this hole 41, and the culture vessel 14 surrounds the control vessel 15.

[0036] The housing 12 is fitted with a plurality of side support plates 42 and a bottom support plate 43 for supporting the culture vessel 14 placed therein, and supports and fixes the culture vessel 14 inserted therein.

[0037] In this embodiment, side support plates 42 are provided at six locations at 60-degree intervals on the inner circumferential surface of the housing 12 and three locations in the vertical direction, for a total of 18 locations, to support the culture vessel 14. In addition, bottom support plates 43 are provided at 60-degree intervals so as to support six locations on the bottom of the culture vessel 14. The support plates 42 and 43 may be molded integrally with the housing 12 from polycarbonate resin, or may be made from acrylic plates and adhesively fixed to the housing 12.

[0038] A woven tube 44 made of glass fiber is installed in a double spiral structure inside the culture vessel 14. The upper end of this woven tube 44 is connected to a supply space 45 provided at the top of the control vessel 15, and the lower end is connected to a drainage pipe 21 from inside the control vessel 15.

[0039] One end of a sprinkler pipe 20, which runs from the base 11 through the control vessel 15, is connected to the center of the space 45, and water is supplied to sprinkle water into the space 45. The space 45 also communicates with an opening 29, the top of which is closed by a sealing lid 23. Finely shredded paper, sawdust, and other cellulose materials are introduced into the opening 29 as needed.

[0040] The cellulose material that has entered the space 45 flows into the woven tube 44 together with the water from the sprinkler pipe 20, and flows down in a spiral pattern inside the woven tube 44. This woven tube 44 not only serves as a supply path for the cellulose material and water, but also as a microbial bed for photosynthetic bacteria.

[0041] The culture vessel 14 is filled with fuzzy fiber spheres 46 along with cellulose material and photosynthetic bacteria. These fiber spheres 46 serve as a bacterial bed necessary for the growth of a large number of photosynthetic bacteria. In this example, the fiber spheres 46 are so-called "pom-pom balls," and have a diameter of 30 to 50 mm.

[0042] The bottom of the culture vessel 14 is covered with a layer of porous activated carbon 30 approximately 30 mm thick to purify the water inside the vessel. The water that accumulates at the bottom of the culture vessel 14 is purified by the activated carbon 30 and drained to the outside through the braided tube 44 and the drain pipe 21.

[0043] As in the first embodiment, rod-shaped LED red lights 25 are installed inside the control vessel 15 to illuminate the culture vessel 14 so that the photosynthetic bacteria can remain active even on rainy or cloudy days when sunlight is insufficient, or at night. In this embodiment, 12 red lights 48 are evenly spaced along the cylindrical surface of the control vessel 15.

[0044] In addition, a red film 26 is attached to the outer periphery of the culture vessel 14 in the same manner as in the first embodiment, so that only red light from sunlight is irradiated.

[0045] Warm water at a constant temperature is supplied from a water supply pipe 17 to the space between the housing 12 and the culture vessel 14, circulated within the housing, and drained to the outside via a drain pipe 18. The temperature of the warm water is adjusted based on the output of a temperature sensor 49, and is controlled to be kept at approximately 40°C, which is considered optimal for photosynthetic bacteria.

[0046] In the fermenter of this embodiment, when cellulosic materials such as finely shredded paper or sawdust are periodically added through opening 29, they mix with water from sprinkler pipe 20 in space 45 and flow into double-spiral woven tube 44. The cellulosic materials and water flowing down inside woven tube 44 flow out through the micropores of woven tube 44 and are appropriately dispersed and supplied into culture vessel 14, allowing hydrogen to be generated in stages by glucose-producing bacteria, etc.

[0047] In this way, the hydrogen generated by the metabolism of photosynthetic bacteria in the culture vessel 14 accumulates in the space 28 provided in the upper part of the culture vessel. When the pressure of the accumulated hydrogen increases, the hydrogen is supplied from the space 28 through the hydrogen discharge pipe 22 to the fuel cell.

[0048] In the fermenter according to the third embodiment, the housing 12 is designed to be cylindrical with a diameter of 100 cm and a height of 100 cm, the culture vessel 14 is cylindrical with a diameter of 80 cm and a height of 80 cm, and the control vessel 15 is cylindrical with a diameter of 25 cm and a height of 100 cm.

[0049] According to the third embodiment, the housing 12, the culture vessel 14 and the control vessel 15 are cylindrical, but they are not limited to cylindrical shapes and may be polygonal pillars such as square pillars or hexagonal pillars.

[0050] Figure 11 shows a schematic diagram of a domestic electric hot water supply system that uses a fermenter 1 according to the present invention. Hydrogen produced from the fermenter 1 is supplied to a fuel cell 101 through a hydrogen discharge pipe 22, and oxygen is supplied directly from the air as an oxygen source 102. In the fuel cell 101, oxygen in the air reacts with the hydrogen from the fermenter to convert it into electrical energy. This fuel cell is a solid polymer fuel cell of the cogeneration type, which can extract thermal energy along with electrical energy.

[0051] Since the electrical energy supplied from the fuel cell is a DC voltage, it must be converted to an AC voltage for home use. Therefore, the DC voltage from the fuel cell 101 is supplied to an inverter 103, which converts it from DC to AC. The converted AC power is supplied to a distribution board 104, which supplies power to various electrical appliances 105, such as lighting in each room of the home. The AC power from the inverter 103 is also supplied to the fermenter 1, and is used to power the red light 25.

[0052] When excess power is generated during the daytime, the DC voltage supplied from the fuel cell is supplied from the controller 106 to the storage battery 107 and stored there. The power from the storage battery 107 is used in the event of a system malfunction or maintenance, or when power consumption exceeds power generation.

[0053] The thermal energy generated by the fuel cell 101 reaches a temperature of approximately 90°C, and this thermal energy is supplied to the heat exchanger 108, where it superheats room-temperature water supplied from a water source 109 by a pump 110 and converts it into hot water. The hot water from the heat exchanger 108 is supplied to a hot water storage tank 111 and temporarily stored therein.

[0054] Room temperature water from water source 109 is used as water supply to the culture vessel 14 of the fermenter, and is supplied to the water supply pipe 20 of the fermenter by pump 110. For this reason, it is preferable to use well water rather than tap water for bacterial cultivation, and therefore a well is used as water source 109. When this well water is used as domestic water, the room temperature water from pump 110 is passed through sterilizer 116 once before being supplied to the home.

[0055] Room temperature water from water source 109 and hot water from hot water tank 111 are also used as warm water for housing 12. Room temperature water supplied from water source 109 by pump 110 and hot water supplied from hot water tank 111 by pump 112 are supplied to solenoid valve 113. Solenoid valve 113 is controlled by temperature sensor 49 provided in culture vessel 14, and adjusts the temperature of the warm water by changing the mixing ratio of room temperature water and hot water so as to maintain the culture vessel at a constant temperature (preferably about 40°C).

[0056] The hot water from the pump 112 is supplied to a hot water supply system 113 for the kitchen, bathroom, washroom, etc. in the home. When floor heating using hot water is used, a solenoid valve 115 controlled by a temperature sensor 114 that detects the floor temperature is provided, and the water temperature is adjusted to keep the floor temperature constant.

[0057] Systems using such fermenters are environmentally friendly, emitting almost no carbon dioxide or other air pollutants, and also have the advantage of not being affected by damage to the power infrastructure during disasters. In addition, the generated hydrogen can be reacted with oxygen in the air in a fuel cell to produce electricity and heat, which can be used as an energy source in the home, with the advantage that there are almost no energy costs involved, resulting in great economic benefits.

[0058] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the components of the above-described embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and may be modified as appropriate. [Explanation of symbols]

[0059] 1 Fermenter, 12 Housing, 14 Culture vessel, 15 Control vessel, 19 Nylon mesh fungal bed, 25 Red light, 30 Activated carbon layer, 31 Electrolytic cell anode, 32 Electrolytic cell cathode, 44 Braided tube, 46 Fiber sphere fungal bed

Claims

1. A columnar culture vessel and a control vessel are provided in a housing that is transparent to visible light, The culture vessel contains a decomposition material containing photosynthetic bacteria and a member serving as a bacterial bed for the photosynthetic bacteria, and is provided with a means for supplying moisture to the decomposition material; a light-emitting lamp for irradiating the photosynthetic bacteria in the culture vessel is provided in the control vessel; The fermenter apparatus is configured to generate hydrogen from the culture vessel by flowing warm water through the housing to keep the culture vessel within a predetermined temperature range.

2. 2. The fermenter apparatus according to claim 1, wherein the housing, the culture vessel, and the control vessel have a cylindrical structure, the control vessel is installed in the center of the housing, and a plurality of culture vessels are arranged around the control vessel.

3. 2. The fermenter apparatus according to claim 1, wherein the housing, the culture vessel, and the control vessel are arranged concentrically in a three-layer structure, with the control vessel at the center, the culture vessel on its outer side, and the housing on the outer side of the culture vessel.

4. 2. The fermenter apparatus according to claim 1, wherein the bacterial bed member is made of a mesh-like nylon filter, and the nylon filter is stretched in a predetermined shape within the culture vessel.

5. 2. The fermenter apparatus according to claim 1, wherein the bacterial bed members are spheres made of a fibrous material, and the spheres are filled in the culture vessel.

6. 6. The fermentation tank apparatus according to claim 4, wherein a mesh tube is laid inside the culture vessel, and the decomposition material and water are supplied from the upper end of the mesh tube, so that the decomposition material and water can be replenished into the culture vessel.

7. 2. The fermenter apparatus according to claim 1, wherein a red film is attached to the outer peripheral surface of the housing and / or the culture vessel.

8. 8. The fermenter apparatus of claim 7, wherein said light is a red light.

9. 2. The fermenter apparatus according to claim 1, wherein the control vessel is provided with a device for electrolyzing water, and hydrogen generated from the electrolyzer is extracted together with hydrogen generated from the culture vessel.

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