CO2 reduction systems, CO2 reduction methods, management systems

Abstract

We provide CO2 reduction systems and other technologies that can reduce CO2 emissions significantly. [Solution] The CO2 reduction system 1 comprises a generator 10 that crushes plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and an underground storage unit 20 installed underground to store the chips 101 produced by the generator 10.

Description

Technical Field

[0001] The present invention relates to a CO2 reduction system, a CO2 reduction method, and a management system.

Background Art

[0002] Conventionally, a CO2 recovery device has been proposed that is arranged on the downstream side of a combustion furnace that burns a combustion product in which a biomass-derived combustion product and a non-biomass-derived combustion product are mixed, and recovers CO2 in the exhaust gas generated by the combustion furnace (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although it is conceivable to aim for net zero in a format that allows CO2 burned as biomass to be reabsorbed by plants and recovered, it is not easy to achieve a 100% recovery rate. In addition, since CO2 that has become a gas due to combustion diffuses into the atmosphere and its concentration decreases, recovery is not easy. An object of the present invention is to provide a CO2 reduction system and the like that can reduce more CO2.

Means for Solving the Problems

[0005] The present invention completed for such an object is a CO2 reduction system including a generator that pulverizes plants that have absorbed CO2 emitted into the atmosphere to generate chips, and an underground storage unit provided underground for storing the chips generated by the generator. Furthermore, the system may also include an above-ground storage unit provided on the ground for storing the chips generated by the generator, and a first transport unit provided between the above-ground storage unit and the underground storage unit for transporting the chips stored in the above-ground storage unit to the underground storage unit. Furthermore, the first transport unit may allow the chips stored in the ground storage unit to fall by their own weight. From another perspective, the present invention is a CO2 reduction system comprising a generator that crushes plants that have absorbed CO2 emitted into the atmosphere to produce chips, and an underwater storage unit provided in water for storing the chips produced by the generator. Furthermore, the system may also include a ground-level storage unit provided on land for storing the chips generated by the generator, and a second transport unit provided between the ground-level storage unit and the underwater storage unit for transporting the chips stored in the ground-level storage unit to the underwater storage unit. Alternatively, the second transport unit may transport the chips stored in the above-ground storage unit to the underwater storage unit by dropping them into the water and allowing them to sink under their own weight. Furthermore, the second transport unit may also immerse the group of chips in water after dividing them into predetermined quantities and packaging them. Furthermore, the aforementioned second transport unit may also be used to package the chips in a deaerated state. Furthermore, the second transport unit may also package the chips after degassing them and immersing them in a predetermined liquid. Furthermore, the predetermined liquid may have the same or higher specific gravity as the liquid into which the packaged chip is inserted. Furthermore, the predetermined liquid and the liquid to which the liquid is injected may be seawater. Furthermore, the packaging material used to pack the chips may be made of a biodegradable resin that decomposes after a predetermined period of time has elapsed since being placed in water. Furthermore, the underwater storage section may be located in a deep-sea area where methane hydrate can be formed due to the chips. Furthermore, the aforementioned plant may be bamboo. From another perspective, the present invention is a method for reducing CO2 emissions, which involves crushing plants that have absorbed CO2 emitted into the atmosphere to produce chips, and then storing these chips in an underground storage unit or an underwater storage unit. Furthermore, from another perspective, the present invention is a management system that determines the weight of chips produced by crushing plants that have absorbed CO2 emitted into the atmosphere, calculates the amount of CO2 fixed in the chips using the determined weight of the chips, and stores the calculated amount of CO2 in association with identification information of an underground storage unit where the chips are stored underground or identification information of an underwater storage unit where the chips are stored in water. Here, the weight of the chip may be determined using the measured weight of the plant. Alternatively, the amount of CO2 fixed to the chip may be calculated using the measured moisture content of the plant. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a CO2 reduction system and the like that can reduce a larger amount of CO2. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of a schematic configuration of a CO2 reduction system according to the first embodiment. [Figure 2] This is a block diagram showing an example of the functional configuration of a control device. [Figure 3] This figure shows an example of the information stored in the memory unit. [Figure 4] This figure shows an example of a schematic configuration of a CO2 reduction system according to the second embodiment. [Figure 5] Figures (A) through (D) show the flow of the chips, packaged in their packaging, as they sink towards the underwater storage area. [Figure 6] This figure shows an example of the information stored in the memory unit. [Modes for carrying out the invention]

[0008] The embodiments will be described in detail below with reference to the attached drawings. <First Embodiment> Figure 1 is a diagram showing an example of the schematic configuration of the CO2 reduction system 1 according to the first embodiment. Figure 2 is a block diagram showing an example of the functional configuration of the control device 50. The CO2 reduction system 1 (hereinafter sometimes referred to as "System 1") according to the first embodiment is a system that crushes plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and stores the produced chips 101 in the ground.

[0009] System 1 comprises a generator 10 that crushes plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and an underground storage unit 20 located underground for storing the chips 101 produced by the generator 10. System 1 also comprises an above-ground storage unit 30 located above ground for storing the chips 101 produced by the generator 10, and a transport unit 40 located between the above-ground storage unit 30 and the underground storage unit 20, acting as a first transport unit for transporting the chips 101 stored in the above-ground storage unit 30 to the underground storage unit 20. System 1 also includes a management device 50 for managing the amount of CO2 fixed in the chips 101 stored in the underground storage unit 20. Examples of plants include bamboo and trees.

[0010] The generator 10 can be exemplified as a well-known wood chipper. The particle size of the chips 101 produced by the generator 10 can be exemplified as being selected according to the type of underground storage unit 20 and conveying unit 40. The underground storage section 20 can be exemplified as a newly excavated cavity for storing the chips 101. Alternatively, the underground storage section 20 may be a fault line. Furthermore, the underground storage section 20 may be a void formed after the extraction of oil or gas.

[0011] The above-ground storage section 30 can be exemplified as being formed in a cylindrical shape (for example, a circular cylinder shape). The material of the above-ground storage section 30 is not particularly limited, and can be exemplified as being, for example, concrete. As shown in FIG. 1, it can be exemplified that the chips 101 generated by the generator 10 are directly put into the above-ground storage section 30 from the generator 10. When the chips 101 generated by the generator 10 are directly put into the above-ground storage section 30 from the generator 10, it can be exemplified that the plant 100 is transported to a location near the place where the above-ground storage section 30 is installed by a transport vehicle 110 (for example, a truck) and is crushed by the generator 10.

[0012] Also, the chips 101 generated by the generator 10 may be transported by the transport vehicle 110 and put into the above-ground storage section 30 from the transport vehicle 110. When the chips 101 generated by the generator 10 are put into the above-ground storage section 30 from the transport vehicle 110, the chips 101 may be generated by the generator 10 at a location, for example, 50 m or more away from the place where the above-ground storage section 30 is installed. Note that the above-ground storage section 30 may have a bottom for placing the chips 101 at the lowermost part of the cylindrical main body. Also, the above-ground storage section 30 may have a lid for closing the opening of the main body at the uppermost part of the cylindrical main body.

[0013] The transport section 40 can be exemplified as a hole dug from the above-ground storage section 30 to the underground storage section 20. The shape of the hole is not particularly limited. The transport section 40 transports the chips 101 stored in the above-ground storage section 30 to the underground storage section 20 by their own weight. The transport section 40 may be formed before the above-ground storage section 30 is installed, or may be formed after the above-ground storage section 30 is installed. Also, the transport section 40 may be a hole formed naturally instead of an artificially dug hole.

[0014] In the system 1, when the transport section 40 is a hole that connects the above-ground storage section 30 and the underground storage section 20, when the chips 101 are put into the above-ground storage section 30, the put-in chips 101 fall to the underground storage section 20 by their own weight and are stored in the underground storage section 20.

[0015] The management device 50 comprises a control unit 51 that controls the entire management device 50, and a storage unit 52 composed of an HDD or semiconductor memory. The management device 50 also comprises a display unit 53 composed of a liquid crystal display or organic EL display, an operation unit 54 composed of a keyboard, mouse, touch panel, etc., and a communication unit 55 which is a communication interface. The management device 50 can be exemplified as a terminal used by an office worker to manage the amount of CO2 fixed in the chip 101, such as a fixed PC (Personal Computer) or notebook PC. Alternatively, the management device 50 may be a portable terminal carried by the worker, such as a tablet PC, tablet terminal, personal digital assistant (PDA), or multifunction mobile phone (so-called "smartphone"). The management device 50 may be composed of multiple terminals.

[0016] The control unit 51 includes a CPU (Central Processing Unit) (not shown), ROM (Read Only Memory) (not shown), RAM (Random Access Memory) (not shown), etc. The ROM stores the basic program (operating system) and various settings executed by the CPU. The CPU uses the RAM as a work area and executes application programs read from the ROM.

[0017] The control unit 51 includes a calculation unit 511 that calculates the amount of CO2 fixed in the chip 101, and a management unit 512 that manages the total amount of CO2 fixed in the chip 101 stored in the underground storage unit 20 using the amount of CO2 fixed calculated by the calculation unit 511.

[0018] The calculation unit 511 can be exemplified by calculating the amount of CO2 fixed using the following formula (1). CO2 fixation amount = Weight of chip 101 (kg) / (1 + Moisture content (%) / 100) × Carbon content (%) / 100 × CO2 conversion factor ... (1) Here, the carbon content is the ratio of carbon to the dry weight of chip 101, and is the value used to convert from dry weight to carbon content; for example, it is 50%. The CO2 conversion factor is a coefficient used to convert the amount of carbon to the amount of CO2; for example, it is 44 ÷ 12.

[0019] The calculation unit 511 can exemplify estimating the weight (kg) and moisture content (%) of the chip 101 using the following method. For example, when plants 100 are transported by transport vehicle 110, the calculation unit 511 estimates the weight of the chips 101 using the method described below. Specifically, the calculation unit 511 estimates the weight of the chips 101 by subtracting the weight of the transport vehicle 110 before loading the plants 100 from the weight of the transport vehicle 110 with the plants 100 loaded, as measured by the weighing device 120. Furthermore, if, for example, the chips 101 are transported by a transport vehicle, the calculation unit 511 estimates the weight of the chips 101 using the method described below. The weight obtained by subtracting the weight of the transport vehicle 110 before loading the chips 101 from the weight of the transport vehicle 110 with the chips 101 loaded, as measured by the weighing device 120, is estimated as the weight of the chips 101. Furthermore, the calculation unit 511 may estimate the weight of the chips 101 as the weight of the plant 100 placed next to the generator 10 in order to produce the chips 101, for example, by measuring the weight of the plant 100 placed next to the generator 10 using a weighing device (not shown) placed next to the generator 10.

[0020] Furthermore, the calculation unit 511 estimates the moisture content of the plant 100 measured by the moisture meter 130 as the moisture content of the chip 101. Alternatively, the calculation unit 511 may use the moisture content of the chip 101 measured by the moisture meter 130 as the moisture content of the chip 101. The calculation unit 511 may determine the weight measured by the weighing instrument 120 and the moisture content measured by the moisture meter 130 using information input by the operator via the operation unit 54, or it may determine the weight using information received via the communication unit 55.

[0021] Figure 3 shows an example of the information stored in the memory unit 52. The management unit 512 manages the amount of CO2 fixed by the chips 101 stored in the underground storage unit 20 for each underground storage unit 20. For example, as shown in Figure 3, the management unit 512 stores in the storage unit 52 the amount of CO2 fixed by the chips 101 calculated by the calculation unit 511 and the underground storage unit 20 in which the chips 101 are stored, in association with each other. Furthermore, the location in which the chip 101 whose CO2 fixation amount has been calculated by the calculation unit 511 will be stored may be determined using information input by the operator via the operation unit 54, or it may be determined using information received via the communication unit 55.

[0022] For example, when plants 100 transported by transport vehicle 110 are converted into chips 101 by generator 10 and stored in above-ground storage unit 30, the calculation unit 511 calculates the amount of CO2 fixed for each plant 100 transported by transport vehicle 110. The management unit 512 then stores the amount of CO2 fixed for each plant 100 transported by transport vehicle 110, calculated by the calculation unit 511, in association with the underground storage unit 20 where the chips 101 related to the plants 100 are stored. Therefore, if the chips 101 stored in the underground storage unit 20 are due to plants 100 transported in multiple batches by transport vehicle 110, the calculation unit 511 stores the accumulated value of the CO2 fixed amounts for each batch in association with the underground storage unit 20.

[0023] Furthermore, the management unit 512 may store the association between the amount of CO2 fixed by the chip 101 calculated by the calculation unit 511 and the underground storage unit 20 in which the chip 101 is stored, as shown in Figure 3, in a server (not shown) that can communicate with the management device 50 via a network. The network is not particularly limited as long as it is a communication network used for data communication between devices and equipment, and examples include the Internet, WAN (Wide Area Network), and LAN (Local Area Network).

[0024] When storing the data on a server, the management unit 512 of the management device 50 transmits the amount of CO2 fixed by the chip 101 calculated by the calculation unit 511 to the server via the communication unit 55 and the network, along with information (e.g., an identification number) that identifies the underground storage unit 20 in which the chip 101 is stored. The server then stores the amount of CO2 fixed for each underground storage unit 20.

[0025] As described above, System 1 comprises a generator 10 that crushes plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and an underground storage unit 20 installed underground to store the chips 101 produced by the generator 10. According to System 1, since the plants 100 that have already fixed CO2 are fixed in that state without being burned, costs and effort can be reduced and more CO2 can be reduced compared to, for example, the case where CO2 that has been converted into gas through combustion is separated and recovered. This is because System 1 does not require the use of chemical adsorbents or membranes that are necessary for the separation and recovery of gaseous CO2. In addition, the volume required to fix the same weight of CO2 is smaller when fixing it in the form of chips 101 than when storing gaseous CO2.

[0026] When plant materials such as bamboo and wood (100) are left in the atmosphere, they will decompose (in other words, decay) due to the action of microorganisms, and eventually react with oxygen in the atmosphere to produce CO2. However, according to System 1, it is possible to store the chips (101) underground, thereby suppressing the progression of the decay of the chips (101). This is because the oxygen concentration underground is low, and the space of the atmosphere surrounding the stored chips (101) can be restricted, reducing the possibility of contact with oxygen. In terms of reducing the possibility of contact with oxygen, it is preferable to block the entrance to the underground storage section (20) and isolate it from the atmosphere when the underground storage section (20) is full of chips (101).

[0027] Even if CO2 is generated by a reaction with oxygen remaining in the underground storage section 20, since CO2 is heavier than oxygen, diffusion to the surface is unlikely, and the CO2 ratio in the underground storage section 20 will increase, suppressing subsequent decomposition reactions. Considering this effect, it is not necessarily required to block the entrance to the underground storage section 20 and cut off access to the atmosphere, and therefore, it is not necessary to excavate underground for the underground storage section 20 and the transport section 40. Faults that are widely distributed in Japan can be used as the underground storage section 20.

[0028] System 1 includes an above-ground storage unit 30 for storing chips 101 generated by the generator 10, and a transport unit 40 located between the above-ground storage unit 30 and the underground storage unit 20 for transporting the chips 101 stored in the above-ground storage unit 30 to the underground storage unit 20. This allows the speed at which chips 101 are generated by the generator 10 to be different from the speed at which chips 101 are injected into the underground storage unit 20, making it possible to generate chips 101 without worrying about the injection speed into the underground storage unit 20.

[0029] The transport unit 40 is designed to allow the chips 101 stored in the above-ground storage unit 30 to fall by their own weight. This makes it possible to inject the chips 101 into the underground storage unit 20 simply by placing them in the above-ground storage unit 30. Furthermore, if the transport unit 40 is a naturally formed hole, costs can be reduced.

[0030] Plant 100 should be bamboo. This is because bamboo has one of the fastest initial growth rates among plants 100, and also has a high rate of regrowth each year. In addition, the life cycle of individual bamboo culms is relatively short, ranging from 5 to 10 years, and some grow so quickly that they can be harvested in just 3 years.

[0031] The above-ground storage section 30 should preferably have a function to apply heat treatment to the stored chips 101. If the plant 100 is a plant containing anaerobic fermentation bacteria such as bamboo, it is preferable to kill the anaerobic fermentation bacteria to suppress fermentation. For example, if the plant 100 is bamboo, it contains many lactic acid bacteria, which are anaerobic fermentation bacteria, so it is preferable to kill the lactic acid bacteria to suppress fermentation. Since lactic acid bacteria are thought to be killed by heating at a temperature of 75°C for 15 minutes, the above-ground storage section 30 should preferably have a function to heat the stored chips 101 at a temperature of 75°C or higher for 15 minutes or more. Also, if the plant 100 is wood, it is preferable to kill the wood-decaying fungi that cause decay to suppress decay. Since wood-rotting fungi are thought to die when heated at a temperature of 40°C for a predetermined time (which can be set according to the type of wood-rotting fungus), if the plant 100 is wood, the above-ground storage unit 30 should have a function to heat the stored chips 101 at a temperature of 40°C or higher for a predetermined time or longer. Furthermore, it is preferable to heat-treat the chips 101 in the above-ground storage section 30 before transporting them to the underground storage section 20 in the transport section 40. Alternatively, the chips 101 may be heat-treated before being stored in the above-ground storage section 30.

[0032] Furthermore, the CO2 reduction method using System 1 involves crushing plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and then storing the produced chips 101 in an underground storage section 20 located underground. This CO2 reduction method can reduce costs and effort compared to, for example, separating and recovering CO2 that has been converted into gas through combustion, and can reduce a larger amount of CO2.

[0033] Furthermore, the management device 50 is an example of a management system that grasps the weight of the chips 101 produced by crushing the plants 100, calculates the amount of CO2 fixed in the chips 101 using the grasped weight, and stores the calculated amount of CO2 fixed in association with the identification information of the underground storage unit 20. According to the management device 50, the amount of CO2 fixed related to the chips 101 stored in the underground storage unit 20 (in other words, the amount of CO2 fixed for each underground storage unit 20) can be managed with high accuracy. As a result, it becomes possible to conduct emission trading based on the amount of CO2 fixed related to the chips 101 stored in the underground storage unit 20 with high accuracy.

[0034] Furthermore, the management device 50 can determine the weight of the chips 101 using the measured weight of the plants 100. This eliminates the need to measure the weight of the chips 101 after they have been produced, making it easy to place the chips 101 into the above-ground storage unit 30. Furthermore, the control device 50 calculates the amount of CO2 fixed to the chips 101 (in other words, the amount of CO2 fixed) using the measured moisture content of the plants 100. This allows for a highly accurate calculation of the amount of CO2 fixed to the chips 101.

[0035] Furthermore, if the server stores the association between the amount of CO2 fixed by the chip 101 calculated by the calculation unit 511 and the underground storage unit 20 in which the chip 101 is stored, as shown in Figure 3, the management device 50 and the server will form a management system that manages the amount of CO2 fixed for each underground storage unit 20. Furthermore, in the first embodiment described above, the location for storing the chips 101 is underground, but the location for storing the chips 101 is not limited to underground, and may be underwater, such as in the sea, as shown in the second embodiment described below.

[0036] <Second Embodiment> Figure 4 shows an example of a schematic configuration of the CO2 reduction system 2 according to the second embodiment. The CO2 reduction system 2 (hereinafter sometimes referred to as "System 2") according to the second embodiment reduces CO2, and, similar to System 1 according to the first embodiment described above, produces chips 101 by crushing plants 100 that have absorbed CO2 emitted into the atmosphere (see Figure 1). Also, similar to System 1, the plants can be exemplified as bamboo or wood. However, unlike System 1, which stores the produced chips 101 underground, System 2 is a system that stores the produced chips 101 in water.

[0037] System 2, like System 1, includes a generator 10 that crushes plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and a ground-based storage unit 30 that is installed on land and stores the chips 101 produced by the generator 10 (see Figure 1). System 2 also includes a submerged storage unit 60 that is installed underwater and stores the chips 101. Furthermore, System 2 includes a transport unit 70 that is installed between the ground-based storage unit 30 and the submerged storage unit 60 and serves as a second transport unit to transport the chips 101 stored in the ground-based storage unit 30 to the submerged storage unit 60. In addition, System 2 includes a management device 50 (see Figure 1) that manages the amount of CO2 fixed in the chips 101 stored in the submerged storage unit 60.

[0038] The particle size of the chips 101 produced by the generator 10 (see Figure 1) can be selected according to the type of underwater storage section 60 and transport section 70, similar to system 1. The underwater storage section 60 can be exemplified as a deep-sea area capable of storing the chips 101. The configuration of the chips 101 stored when the underwater storage section 60 is a deep-sea area will be described later.

[0039] The above-ground storage section 30 only needs to be a facility capable of storing the chips 101 before transport, so its shape and material are not particularly limited. For example, it could be molded into a cylindrical shape (e.g., cylindrical), made of concrete, and capable of holding the chips 101 transported by the transport vehicle 110, similar to system 1 shown in Figure 1. Unlike system 1, system 2 stores the chips 101 in water, so a facility like the transport section 40 in Figure 1 is basically unnecessary. However, since underground storage and underwater storage of the chips 101 can be used in combination, a facility like the transport section 40 in Figure 1 may be provided in system 2.

[0040] The transport unit 70 can be exemplified as a vessel that transports the chips 101 unloaded from the land-based storage unit 30 to the underwater storage unit 60, as shown in Figure 4. If the transport unit 70 is a vessel, for example, as a specific example, an oil tanker (vessel) with a capacity of approximately 300,000 metric tons (MT) emits approximately 10,000 tons (t) of CO2 when making one round trip to the Middle East. In contrast, if an oil tanker (vessel) traveling from Japan to the Middle East is loaded with approximately 5,500 tons (t) of chips 101 and released into the ocean along the way, it is calculated that carbon neutrality can be achieved, where the amount of CO2 emitted and absorbed balances out to zero. Furthermore, by loading an even larger amount of chips 101 onto a vessel such as an oil tanker and releasing it into the ocean, it becomes possible to achieve negative emissions, which aims to reduce the CO2 concentration in the atmosphere itself.

[0041] Furthermore, the transport unit 70 only needs to be able to transport the chips 101 to the ocean where the underwater storage unit 60 is located, so it is not limited to ships, but may be an aerial vehicle capable of carrying and transporting the chips 101, such as a helicopter, drone, or aircraft.

[0042] The transport unit 70 does not simply drop the chips 101 into the ocean where the underwater storage unit 60 is located, but rather divides the chips 101 into predetermined quantities and drops them into the ocean in packaging material 201. Once dropped into the ocean in packaging material 201, the chips 101 sink towards the seabed due to their own weight.

[0043] Figures 5(A) to (D) show the flow of the divided chips 101 as they sink towards the underwater storage section 60 while still packaged in the packaging material 201. The chips 101 produced by the generator 10 (Figure 5(A)) are packed in packing material 201 and degassed (Figure 5(B)). The chips 101 are then packed in liquid 300 so that the liquid 300 can penetrate the degassed portion (Figure 5(C)), and when deployed into the ocean, they sink by their own weight towards the underwater storage section 60 on the deep seabed (Figure 5(D)).

[0044] Liquid 300 is not particularly limited and may be tap water, for example, but considering its tendency to settle in water, it is preferable that it be a liquid with the same or higher specific gravity as seawater, which is the liquid into which the tip 101 is introduced. Examples of such liquids include seawater, as well as glycerol, propylene glycol, high-concentration saline solution, potassium carbonate solution, and sorbitol solution, which have a low impact on the marine environment.

[0045] The packaging material 201 used to package the chips 101 is not particularly limited as long as it sinks under its own weight without floating on the surface of the sea when the chips 101 are packaged inside. For example, a resin film bag that does not permeate seawater or a fiber bag that does permeate seawater can be used as examples. Furthermore, considering the protection of the natural environment, it is preferable that the packaging material 201 be made of a material that decomposes after a predetermined period of time when immersed in seawater. Examples of such materials include biodegradable resins such as PLA (polylactic acid), PHA (polyhydroxyalkanoate), PVA (polyvinyl alcohol), and PCL (polycaprolactone).

[0046] System 2, like System 1, includes a management device 50 (see Figure 1). In the control unit 51 (see Figure 2) of the management device 50 that constitutes System 2, the management unit 512 manages the total amount of CO2 fixed in the chips 101 stored in the underwater storage unit 60 using the amount of CO2 fixed calculated by the calculation unit 511.

[0047] Figure 6 shows an example of the information stored in the memory unit 52 (see Figure 2). The management unit 512, similar to system 1, manages the amount of CO2 fixed by the chips 101 stored in the underwater storage unit 60 for each underwater storage unit 60. For example, as shown in Figure 6, the management unit 512 stores in the storage unit 52 the amount of CO2 fixed by the chips 101 calculated by the calculation unit 511 and the underwater storage unit 60 in which the chips 101 are stored, in association with each other. Furthermore, the location in which the chip 101, whose CO2 fixation amount has been calculated by the calculation unit 511, is stored is not particularly limited. For example, the location of the storage unit 60 may be determined using information input by the operator via the operation unit 54 (see Figure 2), or it may be determined using information received via the communication unit 55 (see Figure 2).

[0048] The management unit 512, similar to system 1, stores the amount of CO2 fixed for each plant 100 (see Figure 1) transported by the transport vehicle 110 (see Figure 1), calculated by the calculation unit 511, in association with the underwater storage unit 60 where the chips 101 related to the plants 100 are stored. Therefore, if the chips 101 stored in the underwater storage unit 60 are due to plants 100 transported in multiple trips by the transport vehicle 110, the cumulative value of the CO2 fixed amounts for multiple trips calculated by the calculation unit 511 is stored in association with the underwater storage unit 60.

[0049] Furthermore, similar to System 1, the management unit 512 may store the association between the amount of CO2 fixed by the chip 101 and the underwater storage unit 60 in which the chip 101 is stored, as illustrated in Figure 6, in a server (not shown) that can communicate with the management device 50 via a network. In this case, the management unit 512 transmits the amount of CO2 fixed by the chip 101 calculated by the calculation unit 511, along with information identifying the underwater storage unit 60 in which the chip 101 is stored (e.g., an identification number), to the server via the communication unit 55 and the network. The server then stores the amount of CO2 fixed for each underwater storage unit 60.

[0050] As described above, System 2 comprises a generator 10 that crushes plants that have absorbed CO2 released into the atmosphere to produce chips 101, and an underwater storage unit 60 that is installed in water to store the chips 101 produced by the generator 10. According to System 2, similar to System 1, the plants 100 that have already fixed CO2 are fixed in that state without being burned. This reduces costs and effort compared to, for example, separating and recovering CO2 that has been converted to gas through combustion, and allows for the reduction of a larger amount of CO2. This is because it eliminates the need for chemical adsorbents or membranes required for the separation and recovery of gaseous CO2. Furthermore, the volume required to fix the same weight of CO2 is smaller when fixing it in the form of chips 101 than when storing gaseous CO2.

[0051] Furthermore, in System 2, since the chips 101 are stored in water, contact between the chips 101 and oxygen (atmosphere) is extremely limited. This suppresses the emission of CO2 due to the aerobic decomposition of the chips 101. In addition, the emission of methane gas due to the anaerobic decomposition of the chips 101 on the seabed can be suppressed by hydrate formation by making the underwater storage section 60 located on the deep seabed at a depth of 500m or more. "Hydration" refers to the process in which methane gas generated by the anaerobic decomposition of the chips 101 on the deep seabed combines with water molecules under low temperature and high pressure to form methane hydrate, which has an ice-like crystalline structure. Since the methane hydrate will exist stably in the sediments on the deep seabed, the surface release of methane gas is suppressed. The methane hydrate originating from the chips 101 can also be recovered and reused as energy.

[0052] Furthermore, in the case of System 2, a shipping company's vessel may be used as the transport unit 70. In this case, by utilizing the vessel used by shipping companies when transporting cargo by sea as the transport unit 70, the transportation costs of the chips 101 can be reduced. In addition, by cooperating with local governments and other organizations in the business of producing the chips 101, it is possible not only to reduce the costs required for the operation of the entire System 2, but also to contribute to society.

[0053] System 2 includes a ground-based storage unit 30 located on land, which stores the chips 101 generated by the generator 10. System 2 also includes a transport unit 70, which is located between the ground-based storage unit 30 and the underwater storage unit 60, and serves as a second transport unit to transport the chips 101 stored in the ground-based storage unit 30 to the underwater storage unit 60. This allows the speed at which the generator 10 generates the chips 101 to differ from the speed at which the chips 101 are introduced into the water, making it possible to generate the chips 101 without worrying about the speed at which the chips 101 are introduced into the water.

[0054] The transport unit 70 is configured to transport the chips 101 stored in the above-ground storage unit 30 to the underwater storage unit 60 by dropping them into the water and allowing them to sink under their own weight. This makes it possible to store the chips 101 in the underwater storage unit 60 simply by dropping them into the water.

[0055] The transport unit 70 is best suited to divide the group of chips 101 generated by the generator 10 into predetermined quantities, pack them in packaging material 201, and then drop them into the water. This promotes sinking to the seabed due to their own weight.

[0056] The conveying unit 70 is preferable to package the chips 101 in a deaerated state. This further promotes sinking to the seabed due to its own weight. Alternatively, the chips 101 may be packaged after being deaerated and immersed in a predetermined liquid. Such a liquid should have the same or higher specific gravity as the liquid into which the chips 101 packaged in the packaging material 201 will be placed. For example, if the liquid into which the chips 101 will be placed is seawater, as in this embodiment, the "predetermined liquid" may be seawater with the same specific gravity, or a liquid with a higher specific gravity than seawater. This further promotes sinking to the seabed due to its own weight.

[0057] The packaging material 201 used to pack the chip 101 should preferably be made of a biodegradable resin that decomposes after a predetermined period of time following its introduction into water. This allows for operation that takes the natural environment into consideration.

[0058] Furthermore, the CO2 reduction method using System 2 involves crushing the plants 100 that have absorbed CO2 emitted into the atmosphere to produce chips 101, and then storing the produced chips 101 in an underwater storage section 60 provided in water. This CO2 reduction method can reduce costs and effort compared to, for example, separating and recovering CO2 that has been converted into gas through combustion, and can reduce a larger amount of CO2.

[0059] Furthermore, if the server stores the association between the amount of CO2 fixed by the chip 101 calculated by the calculation unit 511 and the underwater storage unit 60 in which the chip 101 is stored, as shown in Figure 6, the management device 50 and the server constitute a management system that manages the amount of CO2 fixed for each underwater storage unit 60.

[0060] <Other Embodiments> In the second embodiment described above, the underwater storage section 60 is located on the deep seabed, but the invention is not limited to this configuration. For example, the underwater storage section 60 may be located in freshwater, such as in a deep lake or pond.

[0061] Furthermore, the first and second embodiments described above may be combined. In this case, the generated chips 101 are temporarily stored in the above-ground storage section 30, then a portion is transported by the transport section 40 to the underground storage section 20 for storage, and a portion is transported by the transport section 70 to the underwater storage section 60 for storage. [Explanation of Symbols]

[0062] 1,2…CO2 reduction system, 10…Generator, 20…Underground storage section, 30…Above-ground storage section, 40,70…Transportation section, 50…Management device (example of management system), 60…Underwater storage section, 100…Plants, 101…Chips, 201…Packaging material, 300…Liquid

Claims

1. CO2 released into the atmosphere ２ A generator that crushes plants that have absorbed the substance to produce chips, An underground storage section is provided underground to store the chips generated by the generator, CO equipped ２ Reduction system.

2. A ground storage unit is provided on the ground and stores the chips generated by the generator, A first transport unit is provided between the above-ground storage unit and the underground storage unit to transport the chips stored in the above-ground storage unit to the underground storage unit, The CO2 according to claim 1, further comprising ２ Reduction system.

3. The first transport unit causes the chips stored in the ground storage unit to fall by their own weight. CO as described in claim 2 ２ Reduction system.

4. CO2 released into the atmosphere ２ A generator that crushes plants that have absorbed the substance to produce chips, A submerged storage section is provided in water and stores the chips generated by the generator, CO equipped ２ Reduction system.

5. A ground storage unit is provided on the ground and stores the chips generated by the generator, A second transport unit is provided between the above-ground storage unit and the underwater storage unit to transport the chips stored in the above-ground storage unit to the underwater storage unit, The CO according to claim 4, further comprising ２ Reduction system.

6. The second transport unit transports the chips stored in the above-ground storage unit to the underwater storage unit by dropping them into the water and allowing them to sink under their own weight. CO as described in claim 5 ２ Reduction system.

7. The second transport unit divides the group of chips into predetermined quantities, packages them, and then places them into the water. The CO reduction system according to claim 6 ２ .

8. The second transport unit packages the chips in a deaerated state. CO as described in claim 7 ２ Reduction system.

9. The second transport unit degassed the chips and packaged them while immersed in a predetermined liquid. CO as described in claim 8 ２ Reduction system.

10. The predetermined liquid has the same or higher specific gravity as the liquid into which the packaged chip is inserted. CO as described in claim 9 ２ Reduction system.

11. The predetermined liquid and the liquid to which the liquid is to be added are seawater. CO according to claim 10 ２ Reduction system.

12. The packaging material used to pack the chips is made of a biodegradable resin that decomposes after a predetermined period of time has elapsed since being placed in water. CO as described in claim 7 ２ Reduction system.

13. The underwater storage section is located in a deep-sea area where methane hydrate can be formed due to the chips. CO as described in claim 4 ２ Reduction system.

14. The plant in question is bamboo. CO according to claim 1 or 4 ２ Reduction system.

15. CO2 released into the atmosphere ２ Plants that have absorbed the substance are crushed to produce chips, and these chips are stored in an underground storage unit or an underwater storage unit. CO ２ Reduction method.

16. CO2 released into the atmosphere ２ Determine the weight of the chips produced by crushing plants that have absorbed the substance. Using the weight of the chip that was determined, the CO fixed to the chip ２ Calculate the quantity, Calculated CO ２ The quantity is stored in association with identification information of an underground storage unit for storing the chips underground or identification information of an underwater storage unit for storing the chips underwater. Management system.

17. The weight of the chip is determined using the measured weight of the plant. The management system according to claim 16.

18. Using the measured water content of the plant, the CO2 fixed to the chip ２ A management system for calculating quantity, according to claim 16.

Images