Storage device and derivation method

Abstract

To provide a storage device capable of efficiently deriving biogas or concentration gas of biogas, and a method for deriving biogas or concentration gas of biogas.SOLUTION: A storage device for storing biogas containing methane gas and carbon dioxide gas, or concentration gas obtained by concentrating methane gas in the biogas, comprises: a tank for storing the biogas or the concentration gas, containing an adsorbent for adsorbing the biogas and the concentrated gas; and an inlet / outlet pipe that is connected to the tank, and introduces the biogas or the concentration gas into the tank and discharges the biogas or the concentration gas from the tank.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a storage device and a delivery method. [Background technology]

[0002] In recent years, biogas derived from the manure of dairy cows, beef cows, and other livestock has been attracting attention due to issues such as global warming and the depletion of fossil fuels. Biogas has been generated mainly at large farms using generators and sold as electricity. However, small and medium-sized farms that do not have generators have not been able to fully utilize biogas. In addition, due to a lack of power transmission networks, even if electricity can be generated, it is difficult to sell the electricity.

[0003] Therefore, a method is being considered in which the collected biogas is stored on each farm in a storage device filled with an adsorbent, and then transported to a collection site for separation and purification. This type of biogas handling is thought to have characteristics similar to the conventional separation and purification of natural gas.

[0004] Patent Document 1 (JP 2002-267097 A) discloses a storage device that adsorbs natural gas using an adsorbent filled in a pressure device, and also discloses that when desorbing natural gas from the adsorbent, desorption is promoted by heating.

[0005] Patent Document 2 (JP 2008-240835 A) discloses a method for recovering and reusing gases such as natural gas by adsorbing them into a pressure-resistant container filled with an adsorbent, and also discloses that the pressure-resistant container is mounted on a vehicle and that the heat of adsorption and desorption is regulated by a temperature control unit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-267097 A [Patent Document 2] JP 2008-240835 A Summary of the Invention [Problem to be solved by the invention]

[0007] The device described in Patent Document 1 is configured on the premise that it will be used in a stationary manner and will store natural gas for a long period of time. Therefore, it is not envisaged to make it portable or to adsorb and desorb natural gas in a short period of time. In addition, a heater is provided on the side of the pressure device to promote desorption, but this configuration is also based on the premise that it will be used in a stationary manner where a heat source can be secured.

[0008] In Patent Document 2, a heat medium pipe and a temperature adjustment unit are provided in a pressure-resistant container, but the specific mechanism is not disclosed.

[0009] An object of the present disclosure is to provide a storage device that can efficiently discharge biogas or concentrated biogas gas, and a method for discharging biogas or concentrated biogas gas. [Means for solving the problem]

[0010] [1] A storage device for storing biogas containing methane gas and carbon dioxide gas, or a concentrated gas obtained by concentrating methane gas in the biogas, A tank for storing the biogas or the concentrated gas, the tank including an adsorbent for adsorbing the biogas and the concentrated gas; A storage device comprising piping connected to the tank, the piping being for introducing the biogas or the concentrated gas into the tank and for discharging the biogas or the concentrated gas from the tank.

[0011] [2] The storage device described in [1], wherein the inlet / outlet piping is connected to a first side of the tank.

[0012] [3] The tank has a longitudinal direction and a lateral direction, The storage device according to [2], wherein the first side is one of the sides that intersects with the longitudinal direction.

[0013] [4] The storage device described in [3], which is installed and used so that the longitudinal direction is horizontal.

[0014] [5] The inlet / outlet pipe includes a first inlet / outlet pipe and a second inlet / outlet pipe, an end of the first inlet / outlet pipe and an end of the second inlet / outlet pipe are installed in the tank; The storage device described in [4], wherein the tip of the first inlet / outlet pipe is located closer to the first side than the tip of the second inlet / outlet pipe.

[0015] [6] A pipe for connecting the tank and the inlet / outlet pipe, comprising a return pipe for returning at least a portion of the biogas or the concentrated gas discharged from the tank to the tank; The return pipe is connected to the first side surface, The tip of the return pipe is installed in the tank, a tip end of the first inlet / outlet pipe is located closer to the first side surface than a tip end of the return pipe, The tip of the second inlet / outlet pipe is located closer to the second side surface than the tip of the return pipe, The storage device according to [5], wherein the second side is a side opposite to the first side.

[0016] [7] The storage device described in [6], wherein the first inlet / outlet pipe, the second inlet / outlet pipe and the return pipe are connected to the vertical lower part of the first side.

[0017] [8] An adsorbent filling section for filling the adsorbent, The storage device according to any one of [3] to [7], wherein the adsorbent loading section is installed on the first side surface.

[0018] [9] a first valve for opening and closing the inlet and outlet pipes; A second valve for opening and closing the return pipe, The storage device according to any one of [6] to [8], wherein the first valve and the second valve are provided on the first side.

[0019]

[10] A storage device described in any one of [1] to [9], which is portable.

[0020]

[11] The storage device according to any one of [1] to

[10] , wherein the biogas is a gas derived from at least one selected from the group consisting of livestock manure and food waste.

[0021]

[12] A method for extracting the biogas or the concentrated biogas from the storage device according to any one of [1] to

[11] , comprising: The discharge method includes a discharge step of discharging the biogas from the tank.

[0022]

[13] The tank has a first side, The extraction method according to

[12] , wherein the biogas or the concentrated gas extracted in the extraction step is extracted from the first side surface.

[0023]

[14] A return step of returning at least a portion of the biogas or the concentrated gas discharged in the discharge step to the tank, At least a portion of the biogas or the concentrated gas discharged in the discharge step is returned to the tank from the first side surface, The extraction method according to

[13] , wherein the return step is carried out while the extraction step is carried out.

[0024]

[15] The method for extracting biogas according to

[14] , wherein in the return process, at least a portion of the biogas extracted from the tank is compressed and returned to the tank. Effect of the Invention

[0025] According to the present disclosure, it is possible to provide a storage device capable of efficiently discharging biogas or concentrated biogas gas, and a method for discharging biogas or concentrated biogas gas. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a storage device in this embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing another example of the configuration of the storage device in this embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing another example of the configuration of the storage device in this embodiment. [Figure 4] FIG. 4 is a schematic diagram showing another example of the configuration of the storage device in this embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing another example of the configuration of the storage device in this embodiment. [Figure 6] FIG. 6 is a schematic diagram showing another example of the configuration of the storage device in this embodiment. [Figure 7] FIG. 7 is a schematic diagram showing an example of a tank provided in the storage device in this embodiment. [Figure 8] FIG. 8 is a schematic diagram showing another example of the tank provided in the storage device in this embodiment. [Figure 9] FIG. 9 is a schematic diagram showing another example of the tank provided in the storage device in this embodiment. [Figure 10] FIG. 10 is a schematic diagram showing an example of a method for filling a tank provided in the storage device in this embodiment with an adsorbent. [Figure 11] FIG. 11 is a schematic diagram showing another example of the tank provided in the storage device in this embodiment. [Figure 12] FIG. 12 is a schematic diagram showing another example of the tank provided in the storage device in this embodiment. [Figure 13] FIG. 13 is a schematic diagram showing a vehicle equipped with the storage device of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, embodiments of the present disclosure will be described. However, the following description does not limit the scope of the claims.

[0028] <Storage Device> 1 and 2, a storage device 20 in this embodiment includes a tank 1 for storing biogas or concentrated gas obtained by concentrating methane gas in the biogas, and an inlet / outlet pipe 2 that is connected to the tank 1 and is used for introducing the biogas or concentrated gas into the tank 1 and discharging the biogas or concentrated gas from the tank 1. The tank 1 is filled with an adsorbent that adsorbs the biogas and the concentrated gas. The storage device 20 in this embodiment will be described below.

[0029] Biogas In this embodiment, the term "biogas" refers to a gas derived from at least one selected from the group consisting of livestock manure and food waste, and contains at least methane and carbon dioxide (CO 2 The concentration of methane in biogas is, for example, 50% by volume or more and 65% by volume or less, and the concentration of CO in biogas is, for example, 50% by volume or more and 65% by volume or less. 2 The concentration of nitrogen in the biogas may be, for example, 1 vol.% or more and 15 vol.% or less, and the concentration of oxygen in the biogas may be, for example, 0.1 vol.% or more and 5 vol.% or less. It is preferable that hydrogen sulfide and moisture are removed from the biogas in advance.

[0030] Concentrated Gas In this embodiment, the term "concentrated gas" refers to a gas obtained by concentrating methane gas in biogas. The concentration of methane gas in the concentrated gas is, for example, 75% by volume or more and 97% by volume or less.

[0031] "tank" 7 is a schematic diagram showing an example of the tank 1 provided in the storage device 20 in this embodiment. The tank 1 stores biogas or concentrated gas. The tank 1 has a pressure-resistant structure.

[0032] The tank 1 preferably has a first side surface 3. In this case, the tank 1 preferably has a second side surface 7. The second side surface 7 is a side surface opposite to the first side surface 3.

[0033] It is preferable that the tank 1 has a longitudinal direction and a lateral direction. When the tank 1 has a first side 3, a second side 7, a longitudinal direction and a lateral direction, the first side 3 and the second side 7 are sides that intersect with the longitudinal direction. That is, the first side 3 and the second side 7 are sides that are parallel to the lateral direction. With reference to FIG. 7, the longitudinal direction is the left-right direction, and the lateral direction is the depth direction of the paper. It is more preferable that the tank 1 is installed and used so that the longitudinal direction is horizontal, as shown in FIG. 7.

[0034] Tank 1 is filled with an adsorbent. The adsorbent is methane and CO 2 An adsorbent capable of adsorbing the above is used. Examples of such adsorbents include activated carbon. Activated carbon is made from, for example, coconut shell, coal, charcoal, phenolic resin, etc. The activated carbon may be, for example, powdered activated carbon, crushed carbon, granulated carbon, etc. The particle size of the activated carbon may be, for example, 0.3 mm or more and 0.8 mm or less. In this embodiment, crushed carbon is preferably used.

[0035] The tank 1 may have an adsorbent filling section 4. There is no particular restriction on the location where the adsorbent filling section 4 is installed, but when the tank 1 has a first side surface 3, a second side surface 7, a longitudinal direction, and a lateral direction, the adsorbent filling section 4 is preferably installed on the first side surface 3 as shown in FIG. 7. By installing the adsorbent filling section 4 on the first side surface 3 and filling the adsorbent with the adsorbent filling section 4 facing upward in the vertical direction, the adsorbent can be efficiently filled into the tank 1 (see FIG. 10). Furthermore, it is more preferable that the adsorbent filling section 4 is connected to the center of the first side surface 3.

[0036] Furthermore, by providing a plurality of adsorbent filling sections 4, the adsorbent can be filled more efficiently. For example, as shown in Fig. 8, one adsorbent filling section 4 may be provided on the first side surface 3 and one on the upper part of the tank 1, or as shown in Fig. 9, one adsorbent filling section 4 may be provided on the first side surface 3 and three on the upper part of the tank 1. Note that the number of adsorbent filling sections 4 provided on the upper part of the tank 1 in Figs. 8 and 9 is merely an example and is not limited thereto.

[0037] The tank 1 may have a frame 9. When the tank 1 has a first side 3, a second side 7, a longitudinal direction, and a lateral direction, the frame 9 may be provided on at least the first side 3 as shown in Fig. 11, or may be provided on both the first side 3 and the second side 7 as shown in Fig. 12.

[0038] Inlet and outlet piping The inlet / outlet pipe 2 is a pipe connected to the tank 1. The biogas or concentrated gas is introduced into the tank 1 or discharged from the tank 1 via the inlet / outlet pipe 2. That is, the inlet / outlet pipe 2 functions as an inlet pipe when the biogas or concentrated gas is introduced into the tank 1, and functions as a discharge pipe when the biogas or concentrated gas is discharged from the tank 1.

[0039] 3-4, the storage device 20 is required to have at least one inlet / outlet pipe 2, and preferably has two inlet / outlet pipes 2 (a first inlet / outlet pipe 2a and a second inlet / outlet pipe 2b). By providing the storage device 20 with the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b, the introduction speed and discharge speed of the biogas or concentrated gas can be increased. When the tank 1 has a first side surface 3, a second side surface 7, a longitudinal direction and a lateral direction, the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b are preferably connected to the first side surface 3.

[0040] Furthermore, when biogas or concentrated gas is introduced into the tank 1, heat of adsorption is generated due to adsorption of the biogas or concentrated gas, causing a rise in temperature of the tank 1. Therefore, by introducing the biogas or concentrated gas from one inlet / outlet pipe 2 and releasing the heat of adsorption from the other inlet / outlet pipe 2, the rise in temperature of the tank 1 can be suppressed.

[0041] In addition, by providing the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b, it is possible to introduce biogas or concentrated gas from one inlet / outlet pipe 2 and discharge biogas or concentrated gas from the other inlet / outlet pipe 2.

[0042] When the biogas or concentrated gas is discharged from the tank 1 through one inlet / outlet pipe 2, the composition of the discharged biogas or concentrated gas may be biased. Therefore, by discharging the biogas or concentrated gas from two inlet / outlet pipes 2, the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b, the composition of the discharged biogas or concentrated gas can be made uniform.

[0043] The inlet / outlet pipe 2 is preferably connected to the first side surface 3 of the tank 1. When the inlet / outlet pipe 2 is connected to the first side surface 3 of the tank 1 and the adsorbent filling section 4 is provided on the first side surface 3 of the tank 1, the connection point of the inlet / outlet pipe 2 is preferably different from the installation point of the adsorbent filling section 4. In this case, the inlet / outlet pipe 2 is preferably connected to the lower part in the vertical direction of the first side surface 3. Note that when the inlet / outlet pipe 2 is composed of a first inlet / outlet pipe 2a and a second inlet / outlet pipe 2b, they are preferably connected in the same manner.

[0044] When the storage device 20 includes one inlet / outlet pipe 2, the tip of the inlet / outlet pipe 2 may be installed in the tank 1. When the storage device 20 includes the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b, and the tank 1 has a first side 3, a second side 7, a longitudinal direction, and a lateral direction, the tip of the first inlet / outlet pipe 2a and the tip of the second inlet / outlet pipe 2b are preferably installed in the tank 1. In this case, the position of the tip of the first inlet / outlet pipe 2a and the position of the tip of the second inlet / outlet pipe 2b may be substantially the same position in the tank 1 as shown in FIG. 4, but it is preferable that the tip of the first inlet / outlet pipe 2a is located closer to the first side 3 than the tip of the second inlet / outlet pipe 2b as shown in FIG. 3. In this way, the biogas or concentrated gas is discharged from different positions in the tank 1, so that the composition of the discharged biogas or concentrated gas can be made uniform.

[0045] The tip of the inlet / outlet pipe 2 preferably has a backflow prevention structure such as a check valve from the viewpoint of preventing backflow of the adsorbent filled in the tank 1. There are no particular limitations on the backflow prevention structure, but examples thereof include a metal mesh, a cloth mesh, and a polymer membrane.

[0046] Return piping The return pipe 6 is a pipe that connects the tank 1 and the inlet / outlet pipe 2. At least a part of the biogas or concentrated gas discharged from the tank 1 returns to the tank 1 via the return pipe 6. In this way, the composition of the discharged biogas or concentrated gas can be made uniform.

[0047] When the storage device 20 includes one inlet / outlet pipe 2 and return pipe 6, and the tank 1 has a first side 3, a second side 7, a longitudinal direction, and a transverse direction, it is preferable that the end of the inlet / outlet pipe 2 and the end of the return pipe 6 are installed in the tank 1. In this case, the position of the end of the inlet / outlet pipe 2 and the position of the end of the return pipe 6 may be substantially the same position in the tank 1, but it is preferable that the end of the inlet / outlet pipe 2 is located closer to the first side 3 or the second side 7 than the end of the return pipe 6. By positioning the end of the inlet / outlet pipe 2 and the end of the return pipe 6 at different positions, it is possible to prevent the biogas or concentrated gas returned through the return pipe 6 from being drawn out of the inlet / outlet pipe 2 before being mixed in the tank 1. In addition, it is preferable that the end of the return pipe 6 is located in the central part of the tank 1 (a part away from the first side 3 and the second side 7). In this way, the biogas or concentrated gas returned to the tank 1 can be mixed uniformly in the tank 1.

[0048] 5-6, when the storage device 20 includes the first inlet / outlet pipe 2a, the second inlet / outlet pipe 2b, and the return pipe 6, and the tank 1 has a first side surface 3, a second side surface 7, a longitudinal direction, and a lateral direction, it is preferable that the end of the first inlet / outlet pipe 2a, the end of the second inlet / outlet pipe 2b, and the end of the return pipe 6 are installed in the tank 1. In this case, the positions of the ends of the first inlet / outlet pipe 2a, the end of the second inlet / outlet pipe 2b, and the end of the return pipe 6 may be substantially the same in the tank 1 as shown in FIG. 6, but it is preferable that the end of the first inlet / outlet pipe 2a is located closer to the first side surface 3 than the end of the return pipe 6, and the end of the second inlet / outlet pipe 2b is located closer to the second side surface 7 than the end of the return pipe 6, as shown in FIG. 5. The end of the first inlet / outlet pipe 2a, the end of the second inlet / outlet pipe 2b, and the end of the return pipe 6 are located at different positions to prevent the biogas or concentrated gas returned via the return pipe 6 from being discharged from the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b before being mixed in the tank 1. In addition, it is preferable that the end of the return pipe 6 is located in the center of the tank 1. In this way, the biogas or concentrated gas returned to the tank 1 can be mixed uniformly in the tank 1.

[0049] The return pipe 6 is preferably connected to the first side surface 3 of the tank 1. When the return pipe 6 is connected to the first side surface 3 of the tank 1 and the adsorbent-filled section 4 is provided on the first side surface 3 of the tank 1, the connection location of the return pipe 6 and the installation location of the adsorbent-filled section 4 are preferably different. In this case, the return pipe 6 is preferably connected to the lower part of the first side surface 3 in the vertical direction. Also, when the inlet / outlet pipe 2 (including the case where the inlet / outlet pipe 2 is composed of the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b) and the return pipe 6 are connected to the first side surface 3 of the tank 1 and the adsorbent-filled section 4 is provided on the first side surface 3 of the tank 1, they are preferably connected in the same manner.

[0050] The end of the return pipe 6 preferably has a backflow prevention structure such as a check valve from the viewpoint of preventing backflow of the adsorbent filled in the tank 1. Examples of the backflow prevention structure include the same backflow prevention structures as those described above.

[0051] "valve" The storage device 20 may include a first valve 5. The introduction of the biogas or concentrated gas into the tank 1 and the discharge of the biogas or concentrated gas from the tank 1 are regulated by the first valve 5. In addition, when the storage device 20 includes the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b, and the tank 1 has a first side 3, a second side 7, a longitudinal direction, and a lateral direction, it is preferable that the storage device 20 includes the first valves 5a and 5b, and that the first valves 5a and 5b are provided on the first side 3 side. By providing the first valves 5a and 5b on the first side 3 side, operation can be easily performed.

[0052] The storage device 20 may include a second valve 8. The return of the biogas or concentrated gas to the tank 1 via the return pipe 6 is regulated by the second valve 8. In addition, when the storage device 20 includes the first valve 5 (including the case where the first valve 5 is composed of the first valves 5a and 5b) and the second valve 8, and the tank 1 has a first side 3, a second side 7, a longitudinal direction and a lateral direction, it is preferable that the first valve 5 and the second valve 8 are provided on the first side 3 side. By providing the first valve 5 and the second valve 8 on the first side 3 side, operation can be performed more easily.

[0053] Compression Method The storage device 20 in this embodiment may include a compressor 13. The compressor 13 compresses at least a part of the biogas or concentrated gas discharged from the tank 1. The pressure of the biogas or concentrated gas discharged from the tank 1 is low. In addition, when the biogas or concentrated gas is discharged from the tank 1, the desorption heat due to the desorption of the biogas or concentrated gas reduces the temperature of the tank 1. It is considered that the discharge of the biogas or concentrated gas is suppressed by the decrease in temperature of the tank 1. Therefore, by compressing at least a part of the biogas or concentrated gas discharged from the tank 1 by the compressor 13 and returning it to the tank 1 by the return pipe 6, the decrease in temperature of the tank 1 can be suppressed and the discharge of the biogas or concentrated gas can be promoted. In addition, even if at least a part of the biogas or concentrated gas discharged from the tank 1 is not returned to the tank 1 by the return pipe 6, the discharge of the biogas or concentrated gas can be promoted by increasing the pressure of the biogas or concentrated gas by the compressor 13.

[0054] "others" The storage device 20 in this embodiment may include a heating means 11, a buffer tank 12 and a cooling means 14. These function when discharging the biogas or concentrated gas.

[0055] The heating means 11 heats the discharged biogas or concentrated gas. The heating means 11 may be used when the temperature of the discharged biogas or concentrated gas is low. The buffer tank 12 temporarily stores the discharged biogas or concentrated gas. The cooling means 14 cools the compressed biogas or concentrated gas. The cooling means 14 may be used when the temperature of the compressed biogas or concentrated gas is high.

[0056] The storage device 20 in this embodiment is preferably used for collecting biogas or concentrated gas derived from the manure of livestock raised on a farm, for example. From this viewpoint, it is preferable to make the storage device 20 portable. For example, as shown in FIG. 13, a vehicle 15 (lorry) equipped with the storage device 20 can be mentioned as a portable device.

[0057] <Derivation method> The discharge method in this embodiment includes a discharge step of discharging the biogas or the concentrated gas from the tank. Hereinafter, the discharge method in this embodiment will be described with reference to Figs.

[0058] (Derivation process) The discharge step is a step of discharging the biogas or concentrated gas from the tank 1.

[0059] In the storage device 20 of this embodiment, the biogas or concentrated gas is discharged from the tank 1 via the inlet / outlet pipe 2. The details of the tank 1 and the inlet / outlet pipe 2 are as described above.

[0060] The biogas or concentrated gas is preferably discharged from the tank 1 via the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b from the first side surface 3. In this manner, the composition of the discharged biogas or concentrated gas can be made uniform.

[0061] (Return process) The discharge method in this embodiment may include a return step of returning at least a part of the biogas or concentrated gas discharged in the discharge step to the tank 1. In this case, the return step is performed while the discharge step is being performed.

[0062] In the storage device 20 of this embodiment, the biogas or concentrated gas is returned to the tank 1 via the return pipe 6. The details of the return pipe 6 are as described above.

[0063] At least a portion of the biogas or concentrated gas discharged in the discharge step is preferably returned to the tank 1 from the first side surface 3. By carrying out the discharge step and the return step from the first side surface 3, the operation of each step can be easily performed.

[0064] The return process is carried out while the discharge process is being carried out. By carrying out the return process while the discharge process is being carried out, the composition of the discharged biogas or concentrated gas can be made uniform.

[0065] In the return step, it is preferable to compress at least a part of the biogas or concentrated gas discharged from the tank 1 and return it to the tank 1. The pressure of the biogas or concentrated gas discharged from the tank 1 is low. In addition, when the biogas or concentrated gas is discharged from the tank 1, the desorption heat due to the desorption of the biogas or concentrated gas lowers the temperature of the tank 1. It is considered that the discharge of the biogas or concentrated gas is suppressed by the lowering of the temperature of the tank 1. Therefore, by compressing at least a part of the biogas or concentrated gas discharged from the tank 1 by the compressor 13 and returning it to the tank 1 by the return pipe 6, the decrease in the temperature of the tank 1 can be suppressed and the discharge of the biogas or concentrated gas can be promoted. EXAMPLES

[0066] The following examples are provided to illustrate, but not to limit, the scope of the claims.

[0067] <Example 1> An apparatus having the configuration shown in FIG. 5 was prepared. Biogas derived from livestock manure was prepared. The biogas contained about 54% by volume of methane and about 10% by volume of CO. 2 The biogas contained about 40% by volume of cadmium, about 5% by volume of nitrogen, and about 1% by volume of oxygen. The components of the biogas were analyzed by gas chromatography. Activated carbon was filled into the tank 1 as an adsorbent. The biogas was filled into the tank 1 via the first inlet / outlet pipe 2a. The temperature of the tank 1 after filling was 40°C.

[0068] Next, biogas was discharged from the tank 1 through the first inlet / outlet pipe 2a and the second inlet / outlet pipe 2b. The discharge amount of biogas was 100 Nm 3 / h. The discharged biogas was heated by the heating means 11 and stored in the buffer tank 12. The temperature of the discharged biogas was adjusted to 20°C by the heating means 11. The stored biogas was compressed to 0.85 MPaG by the compressor 13. The compressed biogas was cooled to 40°C by the cooling means 14. Thereafter, a part of the biogas was returned to the tank 1 through the return pipe 6. The return amount of the biogas was 60 Nm 3 / h. Biogas was extracted for 12 hours.

[0069] <Comparative Example 1> The biogas was discharged in the same manner and under the same conditions as in Example 1, except that a portion of the discharged biogas was not returned to the tank 1 through the return pipe 6 .

[0070] <Evaluation> In Example 1 and Comparative Example 1, the composition of the biogas at point 1 in FIG. 5 immediately after the start of discharge and at the end of discharge, and the temperature of tank 1 at the end of discharge were measured.

[0071] <Result> In Example 1, the biogas at point 1 in FIG. 5 immediately after the start of extraction was about 51% by volume of methane and about 10% by volume of CO. 2 The biogas at point 1 in Figure 6 at the end of extraction contained about 49 vol% methane and about 30 vol% CO. 2 The gas contained about 40% by volume of sodium, about 10% by volume of nitrogen, and about 1% by volume of oxygen. The temperature of the tank 1 at the end of extraction was 18°C.

[0072] On the other hand, in Comparative Example 1, the biogas at point 1 in FIG. 5 immediately after the start of extraction was about 60% by volume of methane and 10% by volume of CO. 2The biogas at point 1 in Figure 6 at the end of extraction contained about 55% methane and about 10% CO. 2 The gas contained about 39.5% by volume of sodium, about 5% by volume of nitrogen, and about 0.5% by volume of oxygen. The temperature of the tank 1 at the end of extraction was 5°C.

[0073] In Example 1, the composition of the biogas immediately after the start of discharging and at the end of discharging, and the temperature of the tank 1 before the start of discharging and at the end of discharging, fluctuated little. On the other hand, in Comparative Example 1, the composition of the biogas immediately after the start of discharging and at the end of discharging, and the temperature of the tank 1 before the start of discharging and at the end of discharging, fluctuated more than in Example 1. Therefore, it is considered that by compressing at least a part of the biogas discharged from the tank 1 and returning it to the tank 1, the composition of the discharged biogas and the temperature of the tank 1 are stabilized.

[0074] In this way, by using the storage device and extraction method described in the present disclosure, it is possible to efficiently extract biogas. In addition, the present disclosure makes effective use of livestock manure that would otherwise be discarded, which can contribute to some of the activities of the Sustainable Development Goals (SDGs).

[0075] The embodiments and examples disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0076] 1 tank, 2 inlet / outlet pipe, 2a first inlet / outlet pipe, 2b second inlet / outlet pipe, 3 first side, 4 adsorbent filling section, 5, 5a, 5b first valve, 6 return pipe, 7 second side, 8 second valve, 9 frame, 11 heating means, 12 buffer tank, 13 compressor, 14 cooling means, 15 vehicle, 20 storage device.

Claims

1. A storage device for storing biogas containing methane gas and carbon dioxide gas, or a concentrated gas obtained by concentrating methane gas in the biogas, A tank for storing the biogas or the concentrated gas, the tank including an adsorbent for adsorbing the biogas and the concentrated gas; A storage device comprising piping connected to the tank, the piping being for introducing the biogas or the concentrated gas into the tank and for discharging the biogas or the concentrated gas from the tank.

2. 2. The storage device of claim 1, wherein the inlet and outlet lines are connected to a first side of the tank.

3. The tank has a longitudinal direction and a transverse direction, The storage device of claim 2 , wherein the first side is one side intersecting the longitudinal direction.

4. 4. The storage device according to claim 3, which is installed and used such that the longitudinal direction is horizontal.

5. The inlet / outlet pipe includes a first inlet / outlet pipe and a second inlet / outlet pipe, an end of the first inlet / outlet pipe and an end of the second inlet / outlet pipe are installed in the tank; The storage device according to claim 4 , wherein a tip of the first inlet / outlet pipe is located closer to the first side surface than a tip of the second inlet / outlet pipe.

6. A piping for connecting the tank and the inlet / outlet piping, the piping including a return piping for returning at least a portion of the biogas or the concentrated gas discharged from the tank to the tank; The return pipe is connected to the first side surface, The tip of the return pipe is installed in the tank, A tip of the first inlet / outlet pipe is located closer to the first side surface than a tip of the return pipe, The tip of the second inlet / outlet pipe is located closer to the second side surface than the tip of the return pipe, The storage device of claim 5 , wherein the second side is the side opposite the first side.

7. The storage device according to claim 6 , wherein the first inlet / outlet pipe, the second inlet / outlet pipe and the return pipe are connected to a vertically lower portion of the first side surface.

8. an adsorbent filling section for filling the adsorbent, The storage device of claim 3 , wherein the adsorbent loading section is disposed on the first side surface.

9. A first valve for opening and closing the inlet and outlet pipes; A second valve for opening and closing the return pipe, 7. The storage device of claim 6, wherein the first valve and the second valve are provided on the first side.

10. 10. The storage device of claim 1 which is portable.

11. The storage device according to claim 1 , wherein the biogas is derived from at least one selected from the group consisting of livestock manure and food waste.

12. A method for extracting the biogas or the concentrated gas from a storage device according to any one of claims 1 to 11, comprising the steps of: The discharge method includes a discharge step of discharging the biogas or the concentrated gas from the tank.

13. the tank has a first side; The method according to claim 12 , wherein the biogas or the concentrated gas discharged in the discharging step is discharged from the first side surface.

14. A return step of returning at least a portion of the biogas or the concentrated gas discharged in the discharge step to the tank, At least a portion of the biogas or the concentrated gas discharged in the discharge step is returned to the tank from the first side surface, The method according to claim 13 , wherein the returning step is carried out while the extracting step is carried out.

15. The method according to claim 14, wherein in the returning step, at least a portion of the biogas or the concentrated gas discharged from the tank is compressed and returned to the tank.

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