Novel storage method for flammable gases

Abstract

To provide a method for storing flammable gases under high pressure at low cost, offering both high storage efficiency and high safety. [Solution] The present invention relates to a method for storing flammable gas, comprising a gas storage container (A) installed in the sea or underwater for storing flammable gas, and a gas supply device (B) for supplying flammable gas to the gas storage container (A), characterized in that the method is carried out sequentially by a step (1) of supplying flammable gas from the gas supply device to the gas storage container (A), and a step (2) of storing the flammable gas in the gas storage container (A).

Description

Technical Field

[0001] The present invention relates to a novel method for storing combustible gas. More specifically, it relates to a method for storing combustible gas that can store the combustible gas under high pressure at low cost, thereby exhibiting high storage efficiency and high safety.

Background Art

[0002] Combustible gas is an important energy source in both domestic infrastructure and industry. Due to its combustible nature, a safe storage method is required. Among them, hydrogen gas is used in energy conversion technologies such as fuel cells to extract the chemical energy generated when it combines with oxygen to form water as electrical energy, and its demand is increasing. As methods for storing hydrogen gas, generally, a method of storing hydrogen as a liquid and a method of using a hydrogen-absorbing alloy that has the property of taking in hydrogen gas can be mentioned.

[0003] However, in the former method, although it improves the storage efficiency rather than simply storing hydrogen gas, it is necessary to place it under low-temperature conditions up to about -250°C to liquefy hydrogen gas, and there are problems in terms of cost. In the latter method, the manufacturing cost of the hydrogen-absorbing alloy is also high, and to release hydrogen gas from the hydrogen-absorbing alloy that has absorbed hydrogen gas, it is necessary to place it under high-temperature conditions of about 300°C.

[0004] Thus, as a technology for improving the cost derived from the temperature conditions during storage or hydrogen release, for example, it is disclosed in Patent Document 1.

[0005] Patent Document 1 discloses a hydrogen storage method that allows for the stable storage of hydrogen in a relatively light quantity and under approximately normal temperature and pressure conditions, and also allows for the easy extraction of the stored hydrogen (Claims, Abstract, Paragraphs 0019-0020 of the Specification). Specifically, this hydrogen storage method is characterized by contacting hydrogen gas with an organic compound (such as cyclodextrins or crown ethers) in a liquid state, followed by cooling to obtain a solid organic compound that incorporates hydrogen (Claims, etc.). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-6096609 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while the method disclosed in Patent Document 1 shows cost improvements, it uses special organic compounds such as cyclodextrins and crown ethers. Furthermore, it has the problem of requiring large amounts of these special organic compounds depending on the amount of hydrogen gas to be stored.

[0008] In other words, even with the method disclosed in Patent Document 1, there was still room for improvement in terms of cost.

[0009] The inventors of this invention diligently investigated a cost-effective and safe method for storing flammable gases such as hydrogen gas without using special equipment or compounds, and discovered the following points. (1) By utilizing the natural law that water pressure increases in proportion to depth (size of water) in the sea or lakes, when a flammable gas storage container is installed in the sea or water, a high y is applied to the flammable gas storage container, which reduces the volume of flammable gas in the container and allows for efficient storage. (2) By storing flammable gases in water or sea (i.e., without contact with the atmosphere), the risk of explosion or other incidents can be greatly reduced or eliminated even if an accident such as a gas leak occurs.

[0010] In other words, the present invention aims to provide a method for storing flammable gases that can be stored under high pressure at low cost, thereby exhibiting high storage efficiency and high safety. [Means for solving the problem]

[0011] The present invention relates to a method for storing flammable gas, comprising a gas storage container (1) installed in the sea or underwater for storing flammable gas, A method for storing flammable gas using a flammable gas to supply the flammable gas to the gas storage container (1), Step (I) of supplying flammable gas from the gas supply device (2) to the gas storage container (1), The gas storage container (1) is characterized by sequentially carrying out the process (II) of storing the flammable gas.

[0012] Furthermore, in the flammable gas storage method of the present invention, the gas supply device (2) is preferably a flammable gas generator and / or a flammable gas transport device.

[0013] Furthermore, in the flammable gas storage method of the present invention, it is preferable that the gas storage container (1) is installed in the sea or underwater at a depth of 20 m or more.

[0014] Furthermore, in the flammable gas storage method of the present invention, it is preferable that the flammable gas is at least one gas selected from the group consisting of hydrogen gas, methane gas, ethane gas, propane gas, butane gas, ethylene gas, and acetylene gas. [Effects of the Invention]

[0015] According to the method for storing combustible gas according to the present invention, combustible gas can be stored (stored, held) with high safety and high efficiency (space saving).

[0016] More specifically, the method for storing combustible gas according to the present invention is (1) Since the combustible gas storage container is installed in the sea or underwater, a high pressure is applied to the combustible gas storage container, and the volume of the combustible gas in the container can be reduced, enabling efficient storage. (2) By storing the combustible gas in water / underwater (i.e., in a state not in contact with the atmosphere), even if an accident such as gas leakage occurs, the risk of explosion or the like can be extremely reduced or eliminated.

Brief Description of the Drawings

[0017] [Figure 1] Figures 1(A) and (B) are diagrams for explaining one aspect of the gas storage container (1) and the gas supply device (2) used in the method for storing combustible gas according to the present invention. [Figure 2] Figure 2 is a diagram for explaining another aspect of the gas storage container (1) and the gas supply device (2) used in the method for storing combustible gas according to the present invention. [Figure 3] Figure 3 is a diagram for explaining the relationship with the water pressure generated when the gas storage container (1) used in the method for storing combustible gas according to the present invention is installed in water or underwater.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the method for storing combustible gas according to the present invention will be described in detail with appropriate reference to the drawings.

[0019] The method for storing combustible gas according to the present invention is a method for storing combustible gas using the gas storage container 1 and the gas supply device 2, as shown in Figures 1(A) and (B), and is characterized by sequentially performing the following steps (I) and (II).

[0020] The gas storage container 1 is a container for storing combustible gas and is installed in the sea or underwater.

[0021] Here, "in the sea" refers to the sea bottom or the sea water, and "underwater" refers to the water bottom or the underwater in the hydrosphere (such as lakes, ponds, rivers, etc.) excluding the sea. Also, "combustible gas" refers to general combustible gases used in industry or in the life infrastructure, and is not particularly limited. For example, hydrogen gas, methane gas, ethane gas, propane gas, butane gas, ethylene gas, acetylene gas, etc. can be mentioned. Also, combustible gas includes mixed gases of methane gas, ethane gas, propane gas, and butane gas, such as liquefied natural gas.

[0022] The type of the gas storage container is not particularly limited. For example, a spherical tank (spherical tank, spherical gas holder), a wet gas holder, a dry seal gas holder, a membrane type gas holder, etc. can be mentioned. Also, the shape of the gas storage container is not particularly limited either. It may be spherical, cylindrical (cylindrical, operating type cylindrical, etc.), spindle-shaped, bell-shaped, irregular shape (amoeba type), and when it is made of a membrane (preferably a multi-layer membrane such as a double membrane), it may be of a variable type. Also, generally, the gas storage container is a pressure-resistant container made of steel, etc., but the material is not particularly limited as long as it can hold combustible gas inside.

[0023] As a method for installing the gas storage container in the sea or underwater, as long as the gas storage container is fixed so as not to drift due to water flow or buoyancy even in the state of storing combustible gas, it is not particularly limited. For example, as shown in Fig. 1(A), the gas storage container may be fixed to the anchor part 7 fixed to the rock formation in the sea or underwater via the mooring chain 6, or concrete or metal sinkers may be placed on the gas storage container and connected to the sinkers to be moored near the sea or underwater. Also, the gas storage container can be suspended from a ship or on land and may be in a mode that can be appropriately moved by a suspension device.

[0024] The number L in Figures 1(A) and 1(B) indicates the length (water depth) from the sea surface X to the gas storage container in the sea. In Figure 1(A), the gas storage container 1 is shown installed in the sea at a container depth L. On the other hand, in Figure 1(B), the gas storage container 1 is shown installed on the seabed Y (at a depth (water depth L) from the sea surface X to the seabed Y). Here, the gas storage container may be installed on the seabed at any water depth. However, as shown in Figure 3, the gas storage container and the stored flammable gas are exposed to water pressure P from all directions. This water pressure reduces the volume of the flammable gas, allowing for high storage efficiency.

[0025] Furthermore, water pressure can be calculated using the following formula (1). For example, at a depth of 10m, the pressure is approximately 100kPa, which is approximately 1 atmosphere.

number

[0026] Furthermore, in order to apply sufficient water pressure to the gas storage container and the stored flammable gas, thereby reducing the volume of the flammable gas and achieving high storage efficiency, the water depth (the depth to which the gas storage container is installed) is preferably 20 m or more, more preferably 100 m or more, even more preferably 500 m or more, and particularly preferably 1000 m or more.

[0027] Furthermore, in the flammable gas storage method according to the present invention, since the storage location is in the sea or underwater, accidents such as explosions or combustion due to static electricity or fire are practically impossible to occur, and storage can be carried out in an extremely safe state.

[0028] Gas supply equipment supplies flammable gas to gas storage containers via gas pipes, and specific examples include flammable gas generators and flammable gas transport devices.

[0029] In the present invention's method for storing flammable gas, the first step is to supply flammable gas from the gas supply device to the gas storage container (1) (I).

[0030] The aforementioned flammable gas generator is equipped with a device for generating flammable gas, and as illustrated in Figure 1, number 2, it is capable of supplying the generated flammable gas to a gas storage container via the gas pipe 3.

[0031] On the other hand, the flammable gas transport device supplies the flammable gas obtained from the flammable gas generator to the gas storage container using a transport means such as a pump.

[0032] Here, the flammable gas generator and flammable gas transporter may be installed in the sea or underwater, as shown in Figure 1. Here, the flammable gas generator and flammable gas transporter may be fixed to the seabed or seabed, or moored to an anchor installed on the seabed or seabed. In this case, the flammable gas supplied from the flammable gas generator and flammable gas transporter is affected by water pressure, so its volume is reduced, and it can be stored in a gas storage container with high storage efficiency.

[0033] Alternatively, the flammable gas generator or flammable gas transporter may be installed at sea (for example, on a tanker) or on land. In Figure 2, the flammable gas transport device 2 is installed on land L, and supplies flammable gas to the gas storage container 1 via the gas pipe 3.

[0034] Furthermore, in the method for storing flammable gas according to the present invention, a step (II) of storing the flammable gas in a gas storage container is performed as a step (I) following the above-described step (I).

[0035] Furthermore, when releasing flammable gas from the gas storage container, it can be supplied to land or sea via the gas pipe 4, as shown in Figures 1 and 2. In this case, the flammable gas can be supplied by its own buoyancy without the use of pumps or other means of transport. As shown in Figure 2, number B, it can be filled into gas cylinders or tanks of large gas tankers and then transported to consumption sites in batches, or it can be supplied directly to consumption sites via gas pipelines. If necessary, the flow rate and velocity may be adjusted using control valves, as shown in Figure 2, number 5.

[0036] [Explanation of symbols]

[0037] 1: Gas storage container 2: Gas supply device 3, 4: Gas pipes 5: Adjustable valve 6: Mooring chain 7: Anchor section X: sea level Y: Undersea Z:Land B: Cylinder L: Water depth P: Water pressure

Claims

1. A gas storage container (1) installed in or underwater for storing flammable gas, A method for storing flammable gas using a gas storage container (1) and a gas supply device (2) for supplying flammable gas, Step (I) of supplying combustible gas from the gas supply device (2) to the gas storage container (1), A method for storing a flammable gas, characterized in that the process (II) of storing the flammable gas is carried out sequentially in a gas storage container (1).

2. The method for storing a flammable gas according to claim 1, characterized in that the gas supply device (2) is a flammable gas generator and / or a flammable gas transport device.

3. The method for storing flammable gas according to claim 1, characterized in that the gas storage container (A) is installed in the sea or underwater at a depth of 20 m or more.

4. The method for storing a flammable gas according to claim 1, characterized in that the flammable gas is at least one gas selected from the group consisting of hydrogen gas, methane gas, ethane gas, propane gas, butane gas, ethylene gas, and acetylene gas.

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