Carbon fixation apparatus and carbon fixation method

Abstract

To provide a carbon fixation device and a carbon fixation method that absorb and fixe carbon dioxide by using photosynthetic organisms supported on a fibrous carrier that is swingably installed in water.SOLUTION: A fibrous carrier 18 that is swingably installed in water and supports photosynthetic organisms comprises: a holding plate 9 that extends horizontally from a vertically extending connecting plate 2A and hangs down the plurality of fibrous carriers 18; a rectangular cylinder 3 that connects the vertically extending connecting plates 2A to 2D and surrounds the suspended fibrous carriers 18; a partition plate 5 that is placed at a predetermined distance from the connecting plate 2C opposite the connecting plate 2A and divides the inside of the rectangular cylinder 3; a floating body 4 that is connected to the rectangular cylinder 3 and can float on the water surface; a solar power generation system 13 placed on the floating body 4; and an aeration section 10 provided below a circulation path 19 formed between the partition plate 5 and the connecting plate 2C, thereby allowing the photosynthetic organisms supported on the fibrous carrier 18 to efficiently absorb and fix carbon dioxide.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0001] The present invention relates to a carbon fixation device and a carbon fixation method comprising a fibrous carrier carrying photosynthetic organisms living in water.

Background Art

[0002] Conventionally, it has been known that algae living in coastal shallow waters such as seagrass beds and seaweed beds absorb carbon dioxide by photosynthesis and store the absorbed carbon dioxide as organic matter. The carbon taken up by the algae is called blue carbon and has attracted attention. In particular, eelgrass growing in eelgrass beds has attracted attention as an alga that stores blue carbon, and efforts have been made to increase eelgrass beds in various places.

[0003] Patent Document 1 discloses a technique for constructing an artificial algal bed using artificial seaweed formed of carbon fiber and fixing underwater microorganisms to the artificial algal bed.

[0004] Patent Document 2 discloses a water quality improvement structure for attaching algae and microorganisms to a fibrous outer tube provided on the outer periphery of a resin inner tube and linear fibers provided outside the fibrous outer tube.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Traditionally, seagrass beds have been home to juvenile fish, shellfish, and small animals, supporting the marine ecosystem. Because seagrass absorbs nutrients such as nitrogen and phosphorus as it grows, it also has a water purification function in the sea and is important for organisms living in the sea. However, due to coastal land reclamation and water pollution caused by economic development, seagrass has declined significantly, and its conservation and restoration are urgently needed. As a result of the decline in seagrass, it has become difficult to obtain a stable supply of blue carbon, so there has been consideration to whether it is possible to create artificial seagrass as a substitute for natural seagrass.

[0007] Patent Document 1 describes a technology for forming artificial seaweed beds using carbon fibers to secure habitats for small organisms and fish, and is not a technology for installing artificial seaweed beds for the purpose of absorbing and fixing blue carbon.

[0008] Patent Document 2 describes a technology aimed at improving water quality by having aquatic organisms attached to a water quality improvement structure consume nutrients such as phosphorus in the water, and does not suggest or describe using the water quality improvement structure for the absorption and immobilization of blue carbon.

[0009] The present invention provides a carbon fixation apparatus and a carbon fixation method aimed at allowing photosynthetic organisms attached to a fibrous carrier that can be shaken in seawater to absorb and fix blue carbon. [Means for solving the problem]

[0010] A fibrous carrier for photosynthetic organisms, which is installed in water so as to be able to swing freely, comprises: a holding plate that extends horizontally from a connecting plate A that extends vertically and from which multiple fibrous carriers are suspended; a rectangular tube surrounding the fibrous carriers suspended by connecting the vertically extending connecting plates A, B, C, and D; a partition plate that is positioned at a predetermined distance from a connecting plate C opposite to connecting plate A and divides the inside of the rectangular tube; a floating part connected to the rectangular tube and capable of floating on the water surface; a solar power generation system placed on the floating part; and an aeration part provided below the circulation path formed between the partition plate and connecting plate C. The fibrous carrier consists of a bundle of biodegradable fibers formed into a core material and side material, with the side material sandwiched between two twisted core materials, and is suspended from the intersection of the mesh of a holding plate formed of a mesh member. This allows for the stable absorption and immobilization of carbon, as well as the ability to move the entire device as a single unit. Furthermore, it can efficiently capture photosynthetic organisms and is decomposed by microorganisms, thus not having a negative impact on marine environments.

[0012] The aforementioned rectangular tube is formed from a translucent resin material and configured to float on a buoyancy section provided on its circumferential surface, thereby allowing photosynthetic organisms to perform photosynthesis effectively and increasing the amount of carbon fixed.

[0013] It is installed in the water so as to be able to swing freely, It consists of a bundle of biodegradable fibers formed into a core material and side material, with the side material sandwiched between two twisted core materials. In a fibrous carrier for supporting photosynthetic organisms, a rectangular tubular body is installed in an arbitrary sea area, with connecting plates A, B, C, and D extending vertically surrounding multiple fibrous carriers. Compressed air is supplied upward from an aeration unit installed below a circulation path formed between connecting plate C, which is opposite connecting plate A, and a partition plate that divides the inside of the rectangular tubular body, at a predetermined distance. This generates a circulating flow that circulates around the partition plate and extends from connecting plate A toward the partition plate. net-like retaining plate From the intersection of the mesh By shaking the suspended fibrous carrier, the amount of photosynthetic biomass that can be supported by the fibrous carrier increases, thus increasing the amount of carbon fixed. [Effects of the Invention]

[0014] According to the present invention, carbon dioxide can be efficiently absorbed and fixed by agitating a fibrous carrier supporting photosynthetic organisms in seawater. By generating a circulating flow to enhance the agitation effect of the fibrous carrier, the amount of photosynthetic organisms attached to the carrier increases, thus increasing the amount of carbon fixed. Furthermore, by installing a carbon fixation device composed of fibrous carriers near a sewage discharge area, nutrients in the sewage discharge area are absorbed by the photosynthetic organisms supported on the fibrous carrier, thereby improving water quality and suppressing the occurrence of red tides. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram of the carbon fixation apparatus according to the present invention. [Figure 2] Similarly, this is a cross-sectional view AA in Figure 1. [Figure 3] Similarly, this is a schematic outline of the fibrous carrier. [Modes for carrying out the invention]

[0016] Figure 1 is a schematic diagram of the carbon fixation apparatus according to the present invention. The carbon fixation device 1 of the present invention has a rectangular cylindrical body 3 formed from a plurality of connecting plates 2 extending in the vertical direction, and is configured to float in the sea area on a floating section 4 provided on the outer circumference of the rectangular cylindrical body 3. The rectangular cylindrical body 3 is made of a translucent resin material, which can efficiently capture sunlight coming in from above.

[0017] The rectangular cylindrical body 3 is open at the top and bottom, allowing seawater to flow in from both above and below. A partition plate 5 extending vertically is placed inside, dividing the interior into a seaweed bed area 6 and an aeration area 7. The seaweed bed area 6 contains a seaweed bed 8 consisting of numerous fibrous carriers 18. The upper ends of the fibrous carriers 18 are held by a mesh-like holding plate 9 bridged between the connecting plate 2 and the partition plate 5, and they sway in response to the currents that occur in the sea area. Numerous photosynthetic organisms such as phytoplankton and algae float in the sea area and are held in place by the swaying fibrous carriers 18. In this embodiment, the fibrous carriers 18 are arranged in parallel at predetermined intervals, but the number and spacing of the fibrous carriers 18 can be appropriately set according to the design conditions.

[0018] On the other hand, the aeration zone 7 is the area formed between the partition plate 5 and the connecting plate 2 which is positioned opposite to the partition plate 5 at a predetermined distance, and compressed air is supplied upward from the aeration unit 10 fixedly supported below the partition plate 5. By supplying compressed air from below to above within the aeration zone 7, a circulating flow of seawater is generated. As shown by the arrows, the circulating flow rises through the aeration zone 7, then descends through the partition plate 5 to the seaweed bed zone 6, and then rises again through the aeration zone 7. In other words, it flows while circulating around the partition plate 5.

[0019] The circulating flow circulates around the partition plate 5 while containing photosynthetic organisms inhabiting the sea area. At this time, the fibrous carrier 18 affected by the circulating flow has increased swingability. By circulating the photosynthetic organisms through the fibrous carrier 18 in a highly swingable state, the photosynthetic organisms can efficiently adhere to the fibrous carrier 18, so that the colonization rate and the amount of colonization of the photosynthetic organisms increase. Also, along with the circulation of seawater, carbon dioxide dissolved in the seawater circulates and is efficiently taken up by the fibrous carrier 18. Along with these, it becomes possible to increase the amount of carbon fixation that can be immobilized by the fibrous carrier 18.

[0020] In addition, the sea area where the carbon fixation device 1 is installed is a closed water area near the sewage discharge area rich in nutrient salts such as nitrogen and phosphorus discharged from the sewage treated by the water treatment facility, and since there is little inflow and outflow of water from the outside, nutrient salts such as nitrogen and phosphorus remain. By circulating the nutrient salts together with the circulating flow, they are efficiently taken up by phytoplankton (photosynthetic organisms) that feed on the nutrient salts, and the phytoplankton (photosynthetic organisms) proliferate. Along with the proliferation of phytoplankton (photosynthetic organisms), absorption and fixation of carbon dioxide are efficiently carried out, and the occurrence of red tides can be suppressed by improving the recovery rate of nutrient salts in seawater.

[0021] The floating body part 4 is formed using a member that can float on the sea surface, and is sandwiched from above and below by a pair of clamping parts 11, 11 using fixing members such as bolts not shown in the figure.

[0022] The floating body part 4 mounts an air supply source 12 connected to the air diffusing part 10 via a supply pipe 20 for compressed air and a solar power generation system 13 connected to the air supply source 12. The air supply source 12 may be connected to a commercial power supply, but it is desirable to use the solar power generation system 13 capable of reducing the power consumption and the amount of carbon dioxide emissions.

[0023] The floating body part 4 is provided on the peripheral surface of the square cylinder 3, but as another form, a form in which a floating body part 4 forming an opening connecting underwater and above water is placed on the upper surface of the square cylinder 3 may be used. By providing an opening above the square cylinder 3, the compressed air supplied from the air diffusing part 10 can be released onto the water surface.

[0024] The connecting plate 2, retaining plate 9, and partition plate 5 are made of translucent resin plates of a predetermined thickness to improve the photosynthetic rate of photosynthetic organisms, but the type, shape, length, etc. of the components are not limited. The number of plates used and the method of connection can also be selected as appropriate.

[0025] Furthermore, although the diffuser section 10 is configured with a known diffuser pipe supported below the connecting plate 2, it may also be installed on the partition plate 5 side. The configuration and installation location of the device are not limited as long as it is a mechanism capable of generating a circulating flow. In addition, a carbon dioxide supply means such as a separation membrane device may be installed upstream of the air supply source 12, and concentrated carbon dioxide may be supplied from the diffuser section 10 to supplement the carbon dioxide. By supplying carbon dioxide and increasing the carbon dioxide concentration in the sea area, the photosynthetic efficiency of photosynthetic organisms is improved, and thus the amount of carbon fixed can be increased.

[0026] Figure 2 is a cross-sectional view of AA in Figure 1. The rectangular tube 3 is a cylindrical body formed by connecting connecting plates 2A, 2B, 2C, and 2D, and it surrounds the seaweed bed 8. By providing the rectangular tube 3 around the seaweed bed 8, square Because the sea area inside the cylindrical body 3 is separated from the surrounding sea area, a circulating current can be generated efficiently. For the sake of explanation, of the four connecting plates 2, the connecting plate located on the left when viewed from above will be called connecting plate 2A, and the other connecting plates will be referred to as connecting plates 2B, 2C, and 2D in a clockwise direction.

[0027] The connecting plate 2A supports one end of the retaining plate 9, which extends toward the partition plate 5. The retaining plate 9 is made of a mesh-like member with multiple openings 17 of a predetermined size, through which seawater can flow in and out. One end of a core material 15 (described later in Figure 3) that constitutes a fibrous carrier is fastened to the intersection 14 of the mesh-like member, and the fibrous carrier 18 is suspended from above. By connecting a predetermined number of fibrous carriers 18 to each intersection 14, a seaweed bed of a desired size can be formed. The other end of the retaining plate 9 supports the partition plate 5, whose upper and lower ends extend to predetermined positions.

[0028] The connecting plate 2C, positioned opposite the connecting plate 2A, fixedly supports an aeration section 10 with multiple ejection holes 21 formed at its upper part, and is configured to supply compressed air upwards.

[0029] The partition plate 5, which divides the inside of the rectangular tube 3 into a seaweed bed area 6 and an aeration area 7, bridges from connecting plate 2B to connecting plate 2D, thereby partitioning the inside of the rectangular tube 3.

[0030] The carbon sequestration device 1 described above has an integrated structure, allowing the entire unit to be easily moved to any sea area. The connecting plate 2, holding plate 9, and partition plate 5 that make up the device are connected using known materials such as adhesives and screws, but it is desirable to have a detachable mechanism to facilitate maintenance work such as replacing the fibrous carrier 18.

[0031] As a mechanism for easy attachment and detachment, for example, by installing support columns (not shown) of a predetermined length vertically at the four inner corners of the connecting plates 2A and 2B, partition plate 5, and connecting plate 2D that are in contact with the outer surface of the retaining plate 9, and arranging the retaining plate 9 on the top surface of each support column, the retaining plate 9 only needs to be placed on the top surface of each support column, thus saving time during installation. Furthermore, since the retaining plate 9 can be easily removed when the carbon fixation device 1 is brought up to the surface of the water, replacement is also easy. The retaining plate 9 is pressed downward by the water pressure of the circulating flow flowing in from above and firmly fixed to the top surface of the four support columns, but if the strength is insufficient, support columns may also be provided at the four corners located on the top surface of the retaining plate 9 to clamp it from above and below.

[0032] Figure 3 is a schematic outline of the fibrous carrier. The fibrous carrier 18 is a molded body formed from biodegradable fibers such as natural fibers, regenerated fibers, and biodegradable synthetic fibers, and is composed of a core material and side material made by twisting together yarns made of biodegradable fibers to form a bundle. As shown in Figure 3(a), the fibrous carrier 18 is made by twisting together two core materials 15 and sandwiching a predetermined number of side materials 16 between the twisted core materials 15. The side materials 16 are short fibers that have been sandwiched and held between the core materials 15 and then cut to a predetermined length, and photosynthetic organisms can be captured and fixed in the predetermined voids formed between the short fibers.

[0033] The method of fixing the core material 15 and the side material 16 is not limited to heat welding, fastening, etc., but if heat welding is used, as an example, the core material 15 The core material 15 and the side material 16 can be fixed together by coating one side with a bonding agent such as polyethylene having melt viscosity and then heat-treating it. Heat welding firmly welds the side material 16 to the core material 15, making it difficult for the side material 16 to fall out, and also causes the fibers to become fluffy, creating good voids between the fibers, thus increasing the capture efficiency of photosynthetic organisms.

[0034] As shown in Figure 3(b), the fibrous carrier 18 is a bundle of side members with one end tied together. 16 of 1 The core material 15 of the book may be fixed around it at predetermined intervals. In this embodiment, the core material 15 is molded to be longer than the side material 16, but the length, diameter, shape, etc. of the core material 15 and side material 16 can be appropriately determined according to the design conditions.

[0035] The biodegradable fibers constituting the fibrous carrier 18 have the characteristic of being decomposed into carbon dioxide and water by microorganisms living in nature. Therefore, even if the fibrous carrier 18 is detached from the device due to strong currents, it will disappear over time and will not adversely affect the marine environment. In particular, the muddy areas on the seabed are oxygen-free and the rate of decomposition by microorganisms is slow, so if the fibrous carrier 18 with photosynthetic organisms attached settles on the seabed, it can store carbon dioxide for a long period of time. Furthermore, even if the fibrous carrier 18 does not drift, it is desirable that the carbon dioxide fixed via photosynthetic organisms be ultimately returned to the soil. In this embodiment, since biodegradable fibers are used as the fibrous carrier 18, there is no need to separate the photosynthetic organisms and the fibrous carrier 18 when introducing them into the soil, and both can be directly introduced into the soil as a single unit.

[0036] The fibrous carrier 18 may be formed using fibers other than biodegradable fibers, such as carbon fibers or synthetic resins. Instead of molding the fibers as they are, the fiber surface may be carbonized before molding. Carbonization complicates the surface structure, making it easier for photosynthetic organisms to settle. Furthermore, it is possible to modify the carrier as appropriate, such as by combining multiple fibers or combining it with biodegradable materials other than fibers, such as biodegradable plastics.

[0037] As shown in Figure 1, the fibrous carrier 18 has a retaining plate at one end. 9 Because it is connected and suspended from above, when installed in water the fibrous carrier 18 It can sway in response to ocean currents, just like natural seagrasses such as eelgrass. This swaying increases the surface area of ​​the fibers, allowing photosynthetic organisms floating in seawater to attach to them efficiently.

[0038] Furthermore, the lower end of the fibrous carrier 18 is positioned at a water depth that allows photosynthetic organisms attached to the fibrous carrier 18 to perform photosynthesis effectively. In addition, to prevent photosynthetic organisms from detaching from the fibrous carrier 18 when it is subjected to strong currents, a weight may be attached to the free end of the fibrous carrier 18, or a retaining plate 9 may be added to hold the fibrous carrier 18 from above and below with a pair of retaining plates 9, 9. Furthermore, the lower end of the fibrous carrier 18 may be connected to the retaining plate 9, leaving the upper end as a free end. The method of connecting the fibrous carrier 18 to the retaining plate 9 is also not limited.

[0039] The carbon fixation device of this embodiment is installed near a sewage discharge area where a large amount of nutrients and phytoplankton (photosynthetic organisms) that feed on those nutrients have proliferated. This allows for the attachment of a large amount of phytoplankton, thereby improving carbon fixation efficiency. Furthermore, phytoplankton perform photosynthesis using sunlight and nutrients in the water, producing organic matter to grow and multiply, while simultaneously absorbing carbon dioxide and producing oxygen through photosynthesis. Therefore, by installing a fibrous carrier 18 with a large amount of phytoplankton attached in the sea, carbon dioxide in the seawater can be efficiently absorbed into the fibrous carrier 18.

[0040] Furthermore, while the aim is to absorb and fix carbon dioxide using photosynthetic organisms such as phytoplankton and algae, the type of photosynthetic organism is not limited as long as it is an aquatic organism capable of photosynthesis. Since aquatic organisms that perform photosynthesis, such as seaweed and seagrass, also inhabit the sea area, algae grown in a naturally occurring or known seeding substrate may be transplanted onto the fibrous carrier 18 and used. Alternatively, spores of algae floating in seawater may be attached to the fibrous carrier 18 and grown, and the mature algae may contribute to the absorption and fixation of carbon dioxide as photosynthetic organisms.

[0041] The present invention is not limited to the embodiments described in detail above. Modifications can be made as appropriate without departing from the spirit of the invention. [Industrial applicability]

[0042] This invention is a technology that involves attaching photosynthetic organisms living in seawater to a fibrous carrier to absorb and fix carbon dioxide, thereby contributing to the solution of global warming. Since the fibrous carrier is made of biodegradable fibers and wastewater discharged from water treatment facilities can be effectively utilized, this technology is environmentally friendly. [Explanation of symbols]

[0043] 1. Carbon fixation device 2 Connecting plate 2A connection plate 2B Connecting plate 2C connection plate 2D connection plate 3 square cylinder 4. Floating section 5 partition plates 9 Holding plate 10 Aeration section 13. Solar power generation system 14 Intersection 15 Core material 16 Side material 18. Fibrous carrier 19 Circulation route

Claims

1. In a fibrous carrier (18) that is freely positioned in water and supports photosynthetic organisms, A connecting plate (2A) extends vertically, and a holding plate (9) extends horizontally from which a plurality of fibrous carriers (18) hang down, A rectangular cylindrical body (3) surrounds the fibrous carrier (18) which is suspended by connecting vertically extending connecting plates (2A to 2D), A partition plate (5) is positioned at a predetermined distance from the connecting plate (2A) and the connecting plate (2C) opposite it, dividing the inside of the rectangular tube (3), A floating body (4) is connected to a rectangular cylindrical body (3) and is capable of floating on the water surface, A solar power generation system (13) is mounted on the floating section (4), An aeration section (10) is provided below the circulation path (19) formed between the partition plate (5) and the connecting plate (2C), Equipped with, The fibrous carrier (18) consists of a bundle of biodegradable fibers formed into a core material (15) and side material (16), with the side material (16) sandwiched between two twisted core materials (15), and is suspended from the intersection (14) of the mesh of the holding plate (9) formed of a mesh member. A carbon fixation apparatus characterized by the following features.

2. The rectangular tube (3) is formed from a translucent resin material, It is configured to float using the floating parts (4) provided on its circumferential surface. The carbon fixation apparatus according to feature 1.

3. A fibrous carrier (18) for supporting photosynthetic organisms is installed in water so as to be able to swing freely, and consists of a bundle of biodegradable fibers formed into a core material (15) and side material (16), with the side material (16) sandwiched between two twisted core materials (15), A rectangular cylindrical body (3) is installed in any sea area, with connecting plates (2A to 2D) extending vertically surrounding multiple fibrous carriers (18). Compressed air is supplied upward from an aeration unit (10) located below the circulation path (19) formed between the connecting plate (2A) and the connecting plate (2C) facing it, which is positioned at a predetermined distance from the connecting plate (2C) and the partition plate (5) that divides the inside of the rectangular cylindrical body (3). A circulating flow is generated around the partition plate (5), causing the fibrous carrier (18) hanging from the intersection (14) of the mesh of the mesh-like holding plate (9) that extends from the connecting plate (2A) toward the partition plate (5) to oscillate. A carbon fixation method characterized by the following features.

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