Gas storage container

Abstract

To provide gas storage containers capable of improving an effective storage amount of a gas per volume of a container by making it possible to suppress temperature rise due to gas adsorption on an adsorbent and temperature drop due to gas withdrawal with a simple configuration, and a gas supply method using the gas storage containers.SOLUTION: Gas storage containers for store methane alone or a mixture of methane and carbon dioxide, are provided. Each storage container is made of metal, and has a configuration in which a point where the shortest distance (L) between a surface (S) closest from points (P) and the points (P) among points (P) in an internal space of the storage container is maximum is determined to be the deepest point (Pmax), a distance (Lmax) between the deepest point (Pmax) and the surface (S) is equal to or less than 150 mm, and a ratio of capacity (m3) of the storage container to a surface area (m2) becomes 1:10 to 1:50. The storage container is filled with an adsorbent that adsorbs the gas, and the gas is absorbed below 1 mPa-G.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas storage container that adsorbs and stores methane gas generated from biogas or a mixed gas of methane gas and carbon dioxide using an adsorbent, and more particularly to a gas occlusion container that stores gas in its gaseous state and a gas supply method using the same. [Background technology]

[0002] In recent years, the United Nations has set international goals for sustainable development called the Sustainable Development Goals (SDGs), and there is a strong demand for efforts to create a circular society that increases the utilization of renewable resources and reduces the burden on the environment.

[0003] Therefore, various efforts are being made to effectively utilize organic waste, such as food waste and food waste, that is generated as a result of our life activities. For example, in addition to turning organic waste into animal feed or compost, efforts are being made to convert waste that is difficult to turn into animal feed or compost into energy sources such as biogas, and efforts are also being made to recover and recycle the waste heat. Organic waste is fermented by methane fermentation bacteria, producing biogas that contains methane gas, carbon dioxide, and other trace elements. This biogas is refined to a methane concentration of 90%, making it known as biomethane, and is used as an energy source in a state close to that of fossil fuel natural gas.

[0004] The amount of biogas generated from a single facility is not large, and collection and utilization at the facility is not profitable compared to the cost of installing generators, etc., so there is a problem of appropriate and efficient utilization, and efforts have been made to collect methane refined from biogas to make more efficient use of it. Although gaseous fuels such as natural gas are cooled and liquefied for bulk transportation and transported in low-temperature tanks, methane cannot be liquefied unless it is cooled to -160°C or lower, and it must be transported in storage tanks with heat-resistant structures, so it is rarely used for transporting small amounts of methane gas due to the cost.

[0005] Therefore, the applicant discovered a storage method that enables small and medium amounts of methane to be stored in a container filled with an adsorbent and transported in gas form (see Patent Document 1). According to this method, the heat of adsorption associated with methane adsorption is released to the outside of the system by using a circulating gas, and cooled methane is adsorbed, thereby improving the efficiency of methane adsorption into the adsorbent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-164146 A Summary of the Invention [Problem to be solved by the invention]

[0007] The inventors continued their research and discovered that when adsorbed gas is released, heat equivalent to the heat of vaporization is taken away from the adsorbent, causing the temperature of the adsorbent to drop, making it difficult for the gas to desorb from the adsorbent and reducing the effective adsorption amount.

[0008] The present invention has been proposed in consideration of the above, and provides a gas storage container and a gas supply method using the same that have a simple configuration and can suppress the temperature rise associated with gas adsorption by the adsorbent and the temperature drop associated with gas desorption, thereby improving the effective storage amount of gas per container volume. [Means for solving the problem]

[0009] That is, the first invention is, Gas A storage container is made of metal, and among points (P) in the internal space of the storage container, a point where the shortest distance (L) between the point (P) and a surface (S) closest to the point (P) is the longest is defined as an innermost point (P max ) and the innermost point (P max ) and the distance between the surface (S) (L max ) is 150 mm or less, and the volume (m3 ) and surface area (m 2 The storage container is filled with an adsorbent that adsorbs the gas, and the gas is M The present invention relates to a gas storage container characterized in that the gas is stored at a pressure of less than Pa-G.

[0010] A second invention relates to the gas occlusion container according to the first invention, wherein the adsorbent is activated carbon.

[0011] A third invention relates to the gas occlusion container according to the first or second invention, wherein the adsorbent is a granular adsorbent, and the container is filled with granular adsorbents having two or more different particle sizes.

[0012] A fourth invention relates to the gas occlusion container according to any one of the first to third inventions, wherein the thermal conductivity of the metal is 10 to 250 W / mK.

[0013] A fifth invention relates to the gas storage container of the first invention, wherein the gas is methane alone or a mixed gas of methane and carbon dioxide.

[0014] No. 6 The inventions are the first to 5 The present invention relates to a gas supply method using any one of the gas sorption containers of the above-mentioned invention, wherein, during supply of the gas, when the internal pressure of the gas sorption container is equal to or higher than atmospheric pressure, the gas is released by the internal pressure of the container, and when the internal pressure of the gas sorption container is lower than atmospheric pressure, the gas is sucked in by a vacuum pump. Effect of the Invention

[0015] According to the gas occlusion container of the first invention, Gas A storage container is made of metal, and among points (P) in the internal space of the storage container, a point where the shortest distance (L) between the point (P) and a surface (S) closest to the point (P) is the longest is defined as an innermost point (P max ) and the innermost point (P max ) and the distance between the surface (S) (L max ) is 150 mm or less, and the volume (m 3 ) and surface area (m 2The storage container is filled with an adsorbent that adsorbs the gas, and the gas is M Since the gas is absorbed at less than Pa-G, the adsorbent can be simply configured to suppress the temperature rise associated with gas adsorption and the temperature drop associated with gas desorption, thereby making it possible to increase the effective amount of gas stored per volume of the container.

[0016] According to the gas occlusion container of the second aspect of the invention, the adsorbent is activated carbon, which is suitable for absorbing and releasing gas, and contributes to an increase in the effective storage amount.

[0017] According to the gas storage container of the third invention, in the first or second invention, the adsorbent is a granular adsorbent, and two or more types of granular adsorbent having different particle sizes are filled, so that the amount of adsorbent filled in the gas storage container can be increased.

[0018] According to the gas storage container of the fourth invention, in any of the first to third inventions, the thermal conductivity of the metal is 10 to 250 W / mK, so that heat accompanying the adsorption and desorption of gas can be easily exchanged with the outside by natural heat dissipation.

[0019] According to the gas occlusion container of the fifth invention, in the first invention, the gas is methane alone or a mixed gas of methane and carbon dioxide, so that the cost burden for introducing methane gas power can be reduced.

[0020] No. 6 According to the gas supply method of the present invention, the first to 5 This is a method for supplying gas using any of the gas sorption containers of the present invention, in which, when the internal pressure of the gas sorption container is equal to or higher than atmospheric pressure during supply of the gas, the gas is released by the internal pressure of the container, and when the internal pressure of the gas sorption container is lower than atmospheric pressure, the gas is sucked in by a vacuum pump, so that the gas stored in the gas storage container can be supplied efficiently and the effective storage capacity of the gas storage container can be increased. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a front view showing an embodiment of the gas occlusion container of the present invention, which is unitized into five rows and three columns. [Diagram 2] FIG. 2 is a plan view of the embodiment shown in FIG. [Diagram 3] 1 is a graph showing the change over time in internal temperature associated with the occlusion of methane gas in the gas occlusion containers of prototypes 3 and 4. [Figure 4] 13 is a graph showing the change over time in internal temperature associated with the release of methane gas from the gas occlusion containers of prototypes 3 and 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The gas storage container of the present invention is a gas storage container for storing methane or a mixed gas of methane and carbon dioxide, and is a container for storing the gas in a portable form as it is. Furthermore, since no special equipment, facilities, or handling qualifications are required when storing the gas inside the container or when releasing the stored gas for gas supply, it can be used safely at low cost.

[0023] The gas storage container is filled with an adsorbent that adsorbs the gas to be stored. The adsorbent is preferably a porous material, and in the present invention, activated carbon or silica is used. In particular, activated carbon is preferably used because it has a large gas adsorption capacity per volume and is inexpensive.

[0024] Since the adsorbent is filled into a storage container to adsorb gas, the more the amount of adsorbent filled into the container, the better. From this viewpoint, a granular adsorbent is selected as the adsorbent, and it is preferable that the granular adsorbent has two or more different particle sizes. By using granular adsorbents with different particle sizes, the adsorbent can be packed more densely inside the storage container, and the amount of adsorbent filled is improved. When the adsorbent is stored in the storage container while being subjected to vibration, the dead space in the internal space is reduced, and the amount of adsorbent filled is improved.

[0025] The adsorbent generates heat of adsorption as the gas is adsorbed, and the higher the temperature, the lower the amount of gas adsorbed. Conversely, when the gas is released from the adsorbent, heat equivalent to the heat of evaporation is taken away, the temperature of the adsorbent drops, and the release of the adsorbed gas is delayed. The present invention aims to increase the amount of gas stored and released, and to increase the effective storage amount, by suppressing the temperature change of the adsorbent accompanying the adsorption and desorption of the gas. Furthermore, according to the present invention, the rise or fall of the adsorbent temperature is suppressed by facilitating heat exchange with the outside of the system with a simple configuration, so that no special equipment or facilities are required, it is cost-effective, and it is easy to introduce methane gas power, which also contributes to reducing the environmental load.

[0026] The storage container filled with the adsorbent is made of metal. From the viewpoint of facilitating heat exchange between the adsorbent and the outside of the system, a metal with a thermal conductivity of 10 to 250 W / mK is selected as the metal, and aluminum is particularly preferably used. Aluminum has high thermal conductivity and is lightweight, so it is also suitable for transporting the gas occlusion container. As will be understood from the examples described later, from the viewpoint of heat exchange with the outside of the system, the thermal conductivity of iron, stainless steel, etc. is sufficient, and it is preferably used from the viewpoint of processability and material availability.

[0027] From the viewpoint of heat exchange between the packed adsorbent and the outside of the system, the storage container defines the innermost point (P) as the point within the internal space where the shortest distance (L) between the point (P) and the surface (S) closest to the point (P) is the longest. max ) and the innermost point (P max ) and the distance between the surface (S) (L max ) is designed to be 150 mm or less. It is sufficient that the heat of the adsorbent furthest from the container surface is sufficiently transferred to the metal that composes the container so that the heat of the adsorbent inside the storage container is released to the outside of the storage container. In other words, in the internal space of the storage container, the innermost point (P max ) and the surface (S) max ) is configured to be smaller than 150 mm.

[0028] For example, if the storage container is cylindrical and the inside diameter of the bottom surface is 300 mm or less, the point (P max ) and the side (S) distance (L max ) is 150 mm, and the heat exchange between the adsorbent and the outside of the system is sufficiently good. The shape of the storage container is not particularly limited and may be any appropriate shape. For example, a flat cylindrical shape with a small height or a polygonal prism shape may be considered. In this case, the distance (L max The gas occlusion container of the present invention has a shape in which the width of the container is 150 mm or less. M Since gas is absorbed at less than Pa-G, the internal pressure becomes greater than atmospheric pressure, and therefore a cylindrical shape that is highly resistant to internal pressure is preferable.

[0029] The gas occlusion container of the present invention has an innermost point (P max ) and the distance between the surface (S) (L max ) is 150 mm or less, and the volume of the storage container (m 3 ) and surface area (m 2 ) is specified to be 1:10 to 1:50. As a result, since the surface area of ​​the container is large compared to the volume (volume), heat exchange between the packed adsorbent and the outside of the system becomes smooth, gas adsorption and desorption is performed efficiently, and the effective storage amount is improved. In the present invention, the surface area of ​​the container refers to the internal surface area of ​​the inside of the container.

[0030] As described above, the gas occlusion container of the present invention is configured with a shape having a large surface area relative to the volume, so that the capacity of one gas storage container is relatively small in practice. For this reason, as shown in Figs. 1 and 2, it is preferable that a plurality of gas occlusion containers 10 are connected in parallel by piping 20 and operated as a unit U. For stability and to facilitate heat exchange with the outside of the system, it is preferable that the gas occlusion container is fixed by a frame member 30 that is not covered by an outer wall. For example, the gas occlusion container may be made into a tall cylindrical shape, and in addition to the illustrated example, the unit may be made into 6 rows x 2 columns or 8 rows x 4 columns, etc., and may be appropriately designed according to the size of the loading platform of a transportation vehicle or the scale of gas usage at a gas utilization facility. In this way, the gas occlusion container of the present invention can freely determine the scale of unitization depending on the application, and therefore can be easily handled and can be used for small-scale methane gas utilization, thereby reducing the cost burden of introducing methane gas power.

[0031] The method of storing gas in a gas absorbing container is as follows: first, a vacuum pump is connected to the gas absorbing container to create a vacuum inside the container, and the gas to be absorbed is supplied while being pressurized until the internal pressure of the gas absorbing container reaches 1 M Pa-G less than 0.8, preferably M The gas is supplied until the internal pressure of the gas storage container reaches a certain level. In the case of a unit in which a plurality of gas storage containers are arranged in parallel, the gas is supplied until the internal pressure of each gas storage container reaches a certain level. In this way, the gas storage container of the present invention allows the heat of adsorption of the adsorbent to be naturally released by heat exchange with the outside of the system due to the configuration of the container itself, so that efficient gas storage is possible without requiring any special device or facility.

[0032] The method of supplying the gas stored in the gas absorbing container is performed by opening a valve connected to the gas absorbing container. By opening the valve, the gas is naturally released until the internal pressure of the gas absorbing container becomes the same as the atmospheric pressure. The gas is adsorbed and held in the adsorbent, and it cannot be said that all of the stored gas is released by release only due to the internal pressure of the gas absorbing container, and a certain amount of gas remains inside the container. For this reason, in order to efficiently supply the gas, it is preferable to switch from natural release to suction by a vacuum pump when the internal pressure of the gas absorbing container becomes smaller than the atmospheric pressure. Note that, since it is desirable to supply the gas at a constant pressure when using the gas, it is desirable to switch before the pressure due to the natural supply of the gas attenuates. EXAMPLES

[0033] [Preparation of gas storage container] A prototype was created using a metal tube and adsorbent, as described below. The top and bottom of the tube were sealed with plates of the same material by welding, and a port was attached to the top for supplying and releasing gas.

[0034] [Materials used] Tube 1: Aluminum, inner diameter 86.0 mm, height 1400 mm, thickness 2.0 mm, volume 8.13 L, surface area 0.39 m 2 , volume:surface area=1:47.9, thermal conductivity 250W / mK Tube 2: Steel, inner diameter 93.2 mm, height 1400 mm, thickness 2.4 mm, volume 9.55 L, surface area 0.42 m 2 , volume:surface area=1:44.3, thermal conductivity 10W / mK Tube 3: Aluminum, inner diameter 158.4 mm, height 1000 mm, thickness 3.4 mm, volume 20 L, surface area 0.54 m 2 , volume:surface area=1:27.3, thermal conductivity 250W / mK Tube 4: Aluminum, inner diameter 208.3 mm, height 1000 mm, thickness 4.0 mm, volume 34 L, surface area 0.72 m 2 , volume:surface area=1:21.2, thermal conductivity 250W / mK

[0035] Activated carbon 1: Granular activated carbon Futamura Chemical Co., Ltd.: coconut shell activated carbon "CG130B" (particle size: 500-1700 μm) Activated carbon 2: Granular activated carbon Futamura Chemical Co., Ltd.: coconut shell activated carbon "CG480B" (particle size: 180-355 μm)

[0036] [Prototype 1] Activated carbon 1 and activated carbon 2 were mixed as the adsorbent, and a total of 5.7 kg was filled into a storage container consisting of a tube body 1 to form a gas occlusion container of prototype 1. The volume (m 3 ) and surface area (m 2 The ratio of the distance (L max ) is approximately 43 mm.

[0037] [Prototype 2] Activated carbon 1 and activated carbon 2 were mixed as the adsorbent, and a total of 4.8 kg was filled into a storage container consisting of a tube 2 to form a gas storage container of prototype 2. The volume (m 3 ) and surface area (m 2 The ratio of the distance (L max ) is approximately 46.6 mm.

[0038] [Prototype 3] Activated carbon 1 and activated carbon 2 were mixed as the adsorbent, and a total of 11.1 kg was filled into a storage vessel consisting of a tube 3 to prepare a gas occlusion vessel of prototype 3. The volume (m 3 ) and surface area (m 2 The ratio of the distance (L max ) is approximately 79.2 mm.

[0039] [Prototype 4] Activated carbon 1 and activated carbon 2 were mixed as the adsorbent, and a total of 19.1 kg was filled into a storage container consisting of a tube 4 to form a gas storage container of prototype 4. The volume (m 3 ) and surface area (m 2 The ratio of the distance (L max ) is approximately 104.2 mm.

[0040] [Methane gas storage] In the methane gas absorption and release tests described below, the air inside each prototype gas absorption container was sucked out with a vacuum pump before absorbing methane gas, and the internal pressure was set to approximately -0.1 MPa-G. Methane gas was then supplied at the flow rate specified in each test condition, and continued to be supplied until it was absorbed and the pressure reached 0.8 MPa-G.

[0041] [Methane gas absorption and release test (1)] In order to select a metal suitable for the storage container, a methane gas absorption / release test was carried out using prototypes 1 and 2, which used aluminum and iron tubes. Methane gas was supplied to each prototype at a flow rate of 4 L / min until the internal pressure reached 0.8 MPa-G, and the methane gas was absorbed. The time required for the internal pressure to reach 0.8 MPa-G was 81 minutes for prototype 1 and 71 minutes for prototype 2. The internal pressure (MPa-G), gas supply amount (L), and amount of methane absorbed per unit volume (Nm) over time for each prototype were 3 -CH4 / m 3 ) are shown in Tables 1 and 2. In the tables, the amount of methane absorbed per unit volume (Nm 3 -CH4 / m 3 ) is the storage capacity (Nm 3 -CH4 / m 3 ) is indicated.

[0042] [Table 1]

[0043] [Table 2]

[0044] The release flow rate of the absorbed methane gas was set at 4 L / min, the same as the flow rate during supply, as the specified flow rate, and when the internal pressure of the storage container became the same as atmospheric pressure, the release was performed by switching to suction using a vacuum pump. The amount of methane gas released before the release flow rate fell below the specified flow rate was measured. This release amount can be said to be the effective storage amount. The time it took for the release flow rate to fall below the specified amount was 94 minutes for prototype 1 and 87 minutes for prototype 2. The internal pressure of the gas storage container over time (MPa-G), the amount of gas released (L), and the amount released per unit volume at a flow rate above the specified flow rate (Nm 3 -CH4 / m 3 ) are shown in Tables 3 and 4. In the tables, the amount of discharge per unit volume (Nm 3 -CH4 / m 3 ) is the effective release amount (Nm 3 -CH4 / m 3 ) is indicated.

[0045] [Table 3]

[0046] [Table 4]

[0047] From the results of Tables 1 to 4, the performance differences due to the materials of the storage containers in the methane gas absorption and release tests of Prototypes 1 and 2 are summarized in Table 5.

[0048] [Table 5]

[0049] [Results and Discussion (1)] As shown in Table 5, the amount of methane absorbed per unit volume (Nm 3 -CH4 / m 3 ) and the amount discharged per unit volume at a flow rate equal to or greater than the specified flow rate (Nm 3 -CH4 / m 3), Prototype 1, which is a storage container made of aluminum, gave better results. In other words, the amount of methane gas that can be stored per unit volume is greater in Prototype 1 made of aluminum, and the amount of methane gas released per unit volume from the gas occlusion container is also greater in Prototype 1, and it was found that Prototype 1, which is made of an aluminum tube, has a greater effective storage capacity.

[0050] However, the thermal conductivity of aluminum is approximately 220-240 W / mK, while that of iron is approximately 70-80 W / mK, so there is a difference of about three times, but there is no clear difference in the effective storage amount, and the performance difference was not as great as would be expected from the difference in thermal conductivity. From this, it is considered that a storage container made of metal is sufficient, and stainless steel with a thermal conductivity of 10-20 W / mK can also be used. In other words, it is considered that a storage container made of metal with a thermal conductivity of 10-250 W / mK is sufficient. Rather, it is considered that the shape of the storage container affects the efficient storage of methane gas. In other words, the innermost point (P max ) and the distance between the surface (S) (L max ) and the volume of the storage vessel (m 3 ) and surface area (m 2 ) is considered to be important.

[0051] The specific gravity of aluminum is approximately 2.7 g / cm 3 whereas iron has a density of approximately 7.9 g / cm 3 Therefore, by making the gas occlusion container out of aluminum, the weight can be reduced to about one-third of that of an iron container. For this reason, from the viewpoint of transportation, it can be said that it is more preferable to make the gas occlusion container out of aluminum.

[0052] [Methane gas absorption and release test (2)] Next, a methane gas absorption and release test was conducted to confirm the change in the effective storage amount of methane gas using prototypes 3 and 4, which used a tube with a larger inner diameter of the storage container compared to prototypes 1 and 2. In order to keep the gas passing speed through the adsorbent under the same conditions, the methane gas supply speed per unit area (LV: linear velocity) was standardized to 2.54 mm / sec and the test was conducted. As in the previous test, methane gas was continued to be supplied until it reached 0.8 MPa-G, and methane gas was absorbed. Methane gas was supplied for 310 minutes at a flow rate of 3 L / min for prototype 3, and for 295 minutes at a flow rate of 5.2 L / min for prototype 4. The supply speed (LV) is calculated from the following formula: Supply speed (LV) (mm / sec) = flow rate (L / min) x 1 / 1000 (m 3 / L)×1 / 60(min / sec)×1 / S(1 / m 2 )×1 / 1000(mm / m)

[0053] The internal pressure of the gas storage container (MPa-G), the amount of gas supplied (L), and the amount of methane stored per unit volume (Nm 3 -CH4 / m 3 ) are shown in Tables 6 and 7.

[0054] [Table 6]

[0055] [Table 7]

[0056] The release flow rate of the absorbed methane gas was set as the specified flow rate for each prototype, which was the same as the flow rate when methane gas was supplied, and when the internal pressure of the storage container became the same as atmospheric pressure, suction by the vacuum pump was switched to release the gas. The amount of methane gas released before the release flow rate fell below the specified flow rate was measured. The time it took for the release flow rate to fall below the specified amount was 270 minutes for prototype 3 and 230 minutes for prototype 4. The internal pressure of the gas storage container over time (MPa-G), the amount of gas released (L), and the amount released per unit volume at a flow rate above the specified flow rate (Nm 3 -CH4 / m 3 ) are shown in Tables 8 and 9.

[0057] [Table 8]

[0058] [Table 9]

[0059] From the results of Tables 6 to 9, the performance differences due to the size of the storage container in the methane gas absorption and release tests of Prototypes 3 and 4 are summarized in Table 10.

[0060] [Table 10]

[0061] [Results and Discussion (2)] As shown in Table 10, the amount of methane absorbed per unit volume (Nm 3 -CH4 / m 3 ) and the amount discharged per unit volume at a flow rate equal to or greater than the specified flow rate (Nm 3 -CH4 / m 3), Prototype 3, which is a storage container using a small-diameter tube, gave better results. In other words, the amount of methane gas that can be stored per unit volume is greater in Prototype 3, which is made of a small-diameter tube, and the amount of methane gas released per unit volume from the gas occlusion container is also greater in Prototype 3, and it was found that Prototype 3 has a greater effective storage capacity.

[0062] The graph in Figure 3 shows the change over time in internal temperature associated with the occlusion of methane gas in prototypes 3 and 4. From the start of the supply of methane gas to the gas occlusion container (0 min), the internal temperature gradually increased, reaching a maximum of 41.2°C in prototype 3 and a maximum of 46.6°C in prototype 4. In other words, there was a difference of about 5°C in internal temperature between prototypes 3 and 4 when methane gas was occluded. Due to this difference in temperature change, the amount of methane occluded per unit volume (Nm 3 -CH4 / m 3 ) is thought to have become larger.

[0063] Moreover, the graph shown in FIG. 4 shows the change over time in the internal temperature when methane gas is released from the gas occlusion containers of prototypes 3 and 4. From the start of the release of methane gas from the gas occlusion container (0 min), the internal temperature gradually decreased, dropping to 7.1°C for prototype 3 and 1.4°C for prototype 4. In other words, there was a difference of about 5°C in the internal temperature when methane gas was released between prototypes 3 and 4. Due to this difference in temperature change, the amount released per unit volume (Nm m ) released at a flow rate above the specified flow rate was greater in prototype 3 than in prototype 4. 3 -CH4 / m 3 ) is thought to have increased. In particular, the amount of methane absorbed per unit volume (Nm 3 -CH4 / m 3 ), the amount of gas discharged per unit volume at a flow rate greater than the specified flow rate, compared to the amount of gas stored in the gas storage container (Nm 3 -CH4 / m 3 ), the so-called effective release amount is more affected by temperature changes, 6Nm 3 -CH4 / m 3 The above difference occurred.

[0064] It was shown that by facilitating heat exchange between the adsorbent and the outside of the system, the temperature rise of the adsorbent that occurs when the gas is absorbed is suppressed, so that more gas is absorbed in the gas absorption container, and by suppressing the temperature drop of the adsorbent that occurs when the gas is released, the gas absorbed inside the gas absorption container is easily released from the adsorbent. Therefore, when only the gas absorption and release efficiency is taken into consideration, by using a storage container with a small volume and a large surface area, the distance between the adsorbent and the surface of the storage container is shortened, and heat exchange between the adsorbent and the outside of the system is further promoted.

[0065] In addition, compared to the conventional gas storage container, prototype 4 has a sufficient effective storage capacity as a gas storage container with a simple configuration that does not require special equipment or facilities. From this, it can be said that a gas storage container of an appropriate size can be selected according to the weight reduction of the unit and the size of the transport vehicle. It can be said that this test also showed that the gas storage container of the present invention can increase the effective storage capacity of methane gas without requiring special equipment or facilities, and further has a high degree of freedom in the design of the unit and the device, and is easy to handle.

[0066] From the above test results, it can be said that the shape of the storage container that allows the packed adsorbent to easily exchange heat with the outside of the system contributes to increasing the effective storage amount of gas. In other words, as specified in the present invention, the innermost point (P) is defined as the point within the internal space of the storage container that has the longest shortest distance (L) between the surface (S) closest to the point (P) and the point (P). max ) and the innermost point (P max ) and the distance between the surface (S) (L max ) is 150 mm or less, and the volume of the storage container (m 3 ) and surface area (m 2 By configuring the ratio of the adsorbent to be 1:10 to 1:50, temperature changes in the adsorbent due to natural heat dissipation are suppressed, and the effective storage capacity of the gas occlusion container can be increased with a simple configuration. [Industrial Applicability]

[0067] The present invention relates to Gas The gas storage container does not require any special device or equipment, and can suppress the temperature rise caused by gas adsorption and the temperature drop caused by gas desorption with a simple configuration, thereby making it possible to improve the effective storage amount of gas per volume of the container. Furthermore, since the shape of the container and the scale of the unitization can be freely determined according to demand, the gas storage container of the present invention is easy to handle and can also be used for small-scale methane gas, and the cost burden of introducing methane gas power can be reduced. In other words, it can greatly contribute to reducing the environmental burden. [Explanation of symbols]

[0068] 10 Gas storage container 20 Piping 30 Frame members U-Unit

Claims

1. A gas storage container, comprising: The storage container is made of metal; Among the points (P) in the internal space of the storage container, the point at which the shortest distance (L) between the surface (S) closest to the point (P) and the point (P) is the longest is defined as the innermost point (P ｍａｘ ), and the innermost point (P ｍａｘ ) and the distance between the surface (S) (L ｍａｘ ) is 150 mm or less, and The volume of the storage vessel (m ３ ) and surface area (m ２ ) is configured to be 1:10 to 1:50, The storage container is filled with an adsorbent that adsorbs the gas, The gas is stored at less than 1 MPa-G. A gas storage container characterized by:

2. 2. The gas occlusion container according to claim 1, wherein the adsorbent is activated carbon.

3. 3. The gas occlusion container according to claim 1, wherein the adsorbent is a granular adsorbent, and the container is filled with granular adsorbents having two or more different particle sizes.

4. 4. The gas occlusion container according to claim 1, wherein the thermal conductivity of the metal is 10 to 250 W / mK.

5. A gas storage container as described in claim 1, wherein the gas is methane alone or a mixture of methane and carbon dioxide.

6. A method for supplying gas using the gas occlusion container according to any one of claims 1 to 5, When the internal pressure of the gas occlusion container is equal to or higher than atmospheric pressure during the supply of the gas, the gas is released by the internal pressure of the container, A gas supply method in which the gas is sucked in by a vacuum pump when the internal pressure of the gas storage container is lower than atmospheric pressure.

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