Exhaust gas treatment device and exhaust gas treatment method

Abstract

This exhaust gas treatment device for an engine installed in a work machine comprises a container that accommodates a metal organic structure capable of adsorbing at least one substance contained in exhaust gas, and a compressor for pressurizing the container to which the exhaust gas is supplied.

Description

Exhaust gas treatment device and exhaust gas treatment method

[0001] The present disclosure relates to an exhaust gas treatment device and an exhaust gas treatment method.

[0002] In the technical field of exhaust gas treatment equipment, there is disclosed a method for treating CO emitted from an internal combustion engine, as disclosed in Patent Document 1. ２ Methods for in-vehicle treatment of contained exhaust streams are known.

[0003] Special table 2014-504695 publication

[0004] To protect the global environment, it is necessary to reduce the emission of certain substances contained in engine exhaust gases into the atmosphere.

[0005] The present disclosure aims to recover at least one substance contained in an exhaust gas.

[0006] According to the present disclosure, there is provided an exhaust gas treatment device for an engine mounted on a work machine, the exhaust gas treatment device comprising: a container accommodating a metal organic framework capable of adsorbing at least one substance contained in exhaust gas; and a compressor for pressurizing the container to which the exhaust gas is supplied.

[0007] According to the present disclosure, at least one substance contained in exhaust gas can be recovered.

[0008] Fig. 1 is a diagram showing a work machine according to an embodiment. Fig. 2 is a diagram showing an exhaust gas treatment device for a work machine according to an embodiment. Fig. 3 is a block diagram showing a controller of the exhaust gas treatment device according to an embodiment. Fig. 4 is a diagram for explaining the pressure characteristics of an MOF according to an embodiment. Fig. 5 is a diagram for explaining a control method of the exhaust gas treatment device according to an embodiment. Fig. 6 is a diagram for explaining a control method of the exhaust gas treatment device according to an embodiment. Fig. 7 is a diagram showing an exhaust gas treatment device according to another embodiment.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] [Work Machine] Figure 1 is a diagram showing a work machine 1 according to an embodiment. In the embodiment, the work machine 1 is a wheel loader. The work machine 1 has a vehicle body 2, a traveling unit 3, and a work implement 4. The vehicle body 2 includes a front frame and a rear frame. The front frame and the rear frame are connected via an articulation mechanism. The traveling unit 3 includes wheels 5 attached to the vehicle body 2. The work implement 4 is attached to the front of the vehicle body 2. The work implement 4 has a boom 6 connected to the vehicle body 2, and a bucket 7 connected to the boom 6. The work machine 1 travels on the ground at a work site using the traveling unit 3. The work machine 1 performs work at the work site using the work implement 4. Examples of work performed by the work machine 1 include excavation work, loading work, and transport work.

[0011] [Exhaust Gas Treatment Device] Figure 2 is a diagram showing an exhaust gas treatment device 10 of a work machine 1 according to an embodiment. The work machine 1 has an engine 8 (ICE: Internal Combustion Engine). The engine 8 is mounted on the work machine 1. The exhaust gas treatment device 10 treats exhaust gas from the engine 8. The exhaust gas treatment device 10 is mounted on the work machine 1. The exhaust gas treatment device 10 purifies exhaust gas. The exhaust gas treatment device 10 recovers at least one substance contained in the exhaust gas.

[0012] In the embodiment, the exhaust gas treatment device 10 includes a metal organic framework (MOF). The exhaust gas treatment device 10 treats exhaust gas using the metal organic framework. In the following description, the metal organic framework will be referred to as MOF as appropriate. MOF is a concept that includes porous coordination polymers (PCPs).

[0013] MOFs are complexes with a continuous structure containing metal ions and multidentate organic molecules. MOFs are three-dimensionally continuous coordination structures with nanoporous structures. The combination of metal ions and organic molecules allows MOFs to adsorb only specific substances. When exhaust gas containing a specific substance is supplied to a vessel containing a MOF, the specific substance is adsorbed by the MOF.

[0014] In an embodiment, the specific substance is carbon dioxide (CO ２ ) MOFs are capable of adsorbing carbon dioxide. The exhaust gas treatment device 10 utilizes MOFs to recover at least a portion of the carbon dioxide contained in the exhaust gas.

[0015] As shown in FIG. 2 , the exhaust gas treatment device 10 includes an exhaust gas line 11, a cooler 12, a container compressor 13, a switching valve 14, a treatment line 15, a container 16, a pressure reducer 17, a discharge on-off valve 18, a tank line 19, a tank on-off valve 20, a tank compressor 21, a tank 22, and a pressure sensor 23.

[0016] The exhaust gas line 11 is connected to the engine 8. Exhaust gas from the engine 8 flows through the exhaust gas line 11. The cooler 12 cools the exhaust gas. The cooler 12 is arranged in the exhaust gas line 11. The container compressor 13 pressurizes the exhaust gas. The container compressor 13 is arranged in the exhaust gas line 11. The container compressor 13 pressurizes the exhaust gas cooled by the cooler 12.

[0017] The treatment line 15 is connected to the exhaust gas line 11 via a switching valve 14. The exhaust gas that has flowed through the exhaust gas line 11 passes through the switching valve 14 and then flows through the treatment line 15. The treatment line 15 includes a first treatment line 15A and a second treatment line 15B. The first treatment line 15A and the second treatment line 15B are arranged in parallel with the engine 8. The container 16 includes a first container 16A and a second container 16B. The first container 16A is arranged on the first treatment line 15A. The second container 16B is arranged on the second treatment line 15B. The switching valve 14 switches between a first state in which the exhaust gas that has flowed through the exhaust gas line 11 is supplied to the first container 16A via the first treatment line 15A, and a second state in which the exhaust gas is supplied to the second container 16B via the second treatment line 15B. In the first state, the exhaust gas flowing through the exhaust gas line 11 is supplied to the first container 16A, but not to the second container 16B. In the second state, the exhaust gas flowing through the exhaust gas line 11 is supplied to the second container 16B, but not to the first container 16A. An example of the switching valve 14 is a three-way valve.

[0018] The MOFs are contained in the container 16. The MOFs are contained in each of the first container 16A and the second container 16B. The exhaust gas that has passed through the container compressor 13 flows through the treatment line 15 and is then supplied to the container 16. The MOFs are disposed in the internal space of the container 16. The exhaust gas that has flowed through the treatment line 15 flows into the internal space of the container 16 and comes into contact with the MOFs. The MOFs are capable of adsorbing carbon dioxide. When the exhaust gas comes into contact with the MOFs, the carbon dioxide contained in the exhaust gas is adsorbed by the MOFs.

[0019] The container compressor 13 pressurizes the exhaust gas, thereby pressurizing the container 16 to which the exhaust gas is supplied. The exhaust gas pressurized by the container compressor 13 is supplied to the internal space of the container 16, thereby pressurizing the internal space of the container 16.

[0020] The pressure reducer 17 reduces the pressure in the container 16. The pressure reducer 17 is arranged in the processing line 15 downstream of the container 16. The pressure reducer 17 may also be arranged in the container 16. The pressure reducer 17 reduces the pressure in the internal space of the container 16. The pressure reducer 17 includes a first pressure reducer 17A that reduces the pressure in the first container 16A and a second pressure reducer 17B that reduces the pressure in the second container 16B. An example of the pressure reducer 17 is a vacuum pump.

[0021] Discharge on-off valve 18 is disposed in treatment line 15. Discharge on-off valve 18 opens and closes treatment line 15. Discharge on-off valve 18 is disposed in treatment line 15 downstream of pressure reducer 17. Discharge on-off valve 18 includes a first discharge on-off valve 18A disposed in first treatment line 15A and a second discharge on-off valve 18B disposed in second treatment line 15B.

[0022] The tank line 19 is connected to the container 16. The tank line 19 connects the container 16 and a tank 22. The tank 22 is connected to the container 16 via the tank line 19. The tank line 19 includes a first tank line 19A connected to the first container 16A and a second tank line 19B connected to the second container 16B. The tank 22 includes a first tank 22A connected to the first container 16A via the first tank line 19A and a second tank 22B connected to the second container 16B via the second tank line 19B.

[0023] The tank on-off valve 20 is disposed in the tank line 19. The tank on-off valve 20 opens and closes the tank line 19. The tank on-off valve 20 includes a first tank on-off valve 20A disposed in the first tank line 19A and a second tank on-off valve 20B disposed in the second tank line 19B. The tank compressor 21 is disposed in the tank line 19. The tank compressor 21 is disposed in the tank line 19 between the tank on-off valve 20 and the tank 22. The tank compressor 21 pressurizes the tank 22. The tank compressor 21 pressurizes the internal space of the tank 22. The tank compressor 21 includes a first tank compressor 21A that pressurizes the first tank 22A and a second tank compressor 21B that pressurizes the second tank 22B.

[0024] The pressure sensor 23 detects the pressure in the container 16. The pressure sensor 23 detects the pressure in the internal space of the container 16. The container 16 includes a first pressure sensor 23A that detects the pressure in the first container 16A and a second pressure sensor 23B that detects the pressure in the second container 16B.

[0025] 3 is a block diagram showing a controller 51 of the exhaust gas treatment device 10 according to the embodiment. The exhaust gas treatment device 10 includes the controller 51. The controller 51 outputs control commands to control each of the chiller 12, the container compressor 13, the switching valve 14, the pressure reducer 17, the discharge on-off valve 18, the tank on-off valve 20, and the tank compressor 21. Detection data of the pressure sensor 23 is input to the controller 51.

[0026] The controller 51 includes a computer, a processor 52, a storage device 53, and an input / output interface 54.

[0027] The processor 52 includes a CPU (Central Processing Unit). The processor 52 may also include a GPU (Graphics Processing Unit). The storage device 53 includes a recording medium on which computer programs and data are recorded so as to be readable by the processor 52. The storage device 53 includes a system memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and an auxiliary storage device. Examples of the auxiliary storage device include a hard disk or a semiconductor memory.

[0028] The input / output interface 54 is connected to each of the chiller 12, the container compressor 13, the switching valve 14, the pressure reducer 17, the discharge on-off valve 18, the tank on-off valve 20, the tank compressor 21, and the pressure sensor 23. The processor 52 is connected to each of the chiller 12, the container compressor 13, the switching valve 14, the pressure reducer 17, the discharge on-off valve 18, the tank on-off valve 20, the tank compressor 21, and the pressure sensor 23 via the input / output interface 54.

[0029] [Pressure characteristics] Fig. 4 is a diagram for explaining the pressure characteristics of the MOF according to the embodiment. In the graph shown in Fig. 4, the horizontal axis represents the pressure in the internal space of the container 16 in which the MOF is accommodated, and the vertical axis represents the CO ２ The adsorption amount is shown. As shown in FIG. 4, when a MOF is pressurized, it adsorbs carbon dioxide. When a MOF is depressurized, it releases the adsorbed carbon dioxide. When a MOF is pressurized to a specified value Sh or higher, it adsorbs carbon dioxide. When a MOF is depressurized to a value below the specified value Sh, it releases carbon dioxide. The specified value Sh is an intrinsic value of the MOF that is determined based on the characteristics of the MOF. The specified value Sh is a known value that is stored in advance in the storage device 53.

[0030] When carbon dioxide is adsorbed into the MOF, the controller 51 controls the container compressor 13 so that the pressure in the internal space of the container 16 is pressurized to a specified value Sh or higher. When carbon dioxide is released from the MOF, the controller 51 controls the pressure reducer 17 so that the pressure in the internal space of the container 16 is reduced to a value below the specified value Sh. The carbon dioxide released from the MOF by reducing the pressure in the container 16 is supplied to the tank 22 via the tank line 19 and stored in the tank 22. The controller 51 pressurizes the pressure in the container 16 to a specified value Sh or higher to adsorb carbon dioxide into the MOF, and then reduces the pressure in the container 16 to a value below the specified value Sh, thereby recovering the carbon dioxide contained in the exhaust gas and storing it in the tank 22.

[0031] If the temperature of the MOF exceeds the upper heat resistance limit, the adsorption performance of the MOF for the substance may be reduced. If the temperature of the exhaust gas is equal to or higher than the upper heat resistance limit of the MOF, the adsorption performance of the MOF may be reduced. In the embodiment, the exhaust gas is cooled by a cooler 12. The cooler 12 cools the exhaust gas so that the temperature of the exhaust gas is equal to or lower than the upper heat resistance limit of the MOF.

[0032] [Control Method] Figures 5 and 6 are diagrams for explaining a control method for the exhaust gas treatment device 10 according to the embodiment. Figure 5 shows a state in which the MOF in the first container 16A adsorbs carbon dioxide contained in the exhaust gas and the MOF in the second container 16B releases carbon dioxide. Figure 6 shows a state in which the MOF in the second container 16B adsorbs carbon dioxide contained in the exhaust gas and the MOF in the first container 16A releases carbon dioxide.

[0033] As shown in FIG. 5 , when carbon dioxide is adsorbed by the MOF in the first container 16A, the controller 51 controls the switching valve 14 to enter a first state in which exhaust gas that has passed through the container compressor 13 is supplied to the first container 16A. In the first state, the controller 51 opens the first discharge on-off valve 18A and closes the first tank on-off valve 20A. In the first state, the controller 51 drives the container compressor 13 to pressurize the first container 16A to which the exhaust gas is supplied, and stops driving the first pressure reducer 17A. Based on the detection data of the first pressure sensor 23A, the controller 51 controls the container compressor 13 so that the pressure in the first container 16A is equal to or greater than the specified value Sh. By pressurizing the first container 16A, the MOF in the first container 16A can adsorb carbon dioxide contained in the exhaust gas supplied to the first container 16A. The exhaust gas that has passed through the first container 16A passes through the first discharge on-off valve 18A and is then discharged into the atmosphere. Exhaust gases with reduced amounts of carbon dioxide are released into the atmosphere.

[0034] In the first state, the controller 51 closes the second discharge on-off valve 18B and opens the second tank on-off valve 20B. In the first state, the controller 51 drives the second pressure reducer 17B to reduce the pressure in the second container 16B. Based on the detection data of the second pressure sensor 23B, the controller 51 controls the second pressure reducer 17B so that the pressure in the second container 16B is less than the specified value Sh. As the pressure in the second container 16B is reduced, carbon dioxide is released from the MOF in the second container 16B. The carbon dioxide released from the MOF in the second container 16B flows through the second tank line 19B and is then supplied to the second tank 22B. The controller 51 controls the second tank compressor 21B to pressurize the carbon dioxide supplied to the second tank 22B. As the pressurized carbon dioxide is supplied to the internal space of the second tank 22B, the internal space of the second tank 22B is pressurized and the carbon dioxide is compressed. After the second tank 22B is sufficiently filled with compressed carbon dioxide, the controller 51 closes the second tank opening / closing valve 20B. By closing the second tank opening / closing valve 20B, the carbon dioxide is stored in the second tank 22B.

[0035] As shown in FIG. 6 , when carbon dioxide is adsorbed by the MOF in the second container 16B, the controller 51 controls the switching valve 14 to enter a second state in which the exhaust gas that has passed through the container compressor 13 is supplied to the second container 16B. In the second state, the controller 51 opens the second discharge on-off valve 18B and closes the second tank on-off valve 20B. In the second state, the controller 51 drives the container compressor 13 to pressurize the second container 16B to which the exhaust gas is supplied, and stops driving the second pressure reducer 17B. Based on the detection data of the second pressure sensor 23B, the controller 51 controls the container compressor 13 so that the pressure in the second container 16B is equal to or greater than the specified value Sh. By pressurizing the second container 16B, the MOF in the second container 16B can adsorb carbon dioxide contained in the exhaust gas supplied to the second container 16B. The exhaust gas that has passed through the second container 16B passes through the second discharge on-off valve 18B and is then discharged into the atmosphere. Exhaust gases with reduced amounts of carbon dioxide are released into the atmosphere.

[0036] In the second state, the controller 51 closes the first discharge on-off valve 18A and opens the first tank on-off valve 20A. In the second state, the controller 51 drives the first pressure reducer 17A to reduce the pressure in the first container 16A. Based on the detection data of the first pressure sensor 23A, the controller 51 controls the first pressure reducer 17A so that the pressure in the first container 16A is less than the specified value Sh. As the first container 16A is reduced in pressure, carbon dioxide is released from the MOF in the first container 16A. The carbon dioxide released from the MOF in the first container 16A flows through the first tank line 19A and is then supplied to the first tank 22A. The controller 51 controls the first tank compressor 21A to pressurize the carbon dioxide supplied to the first tank 22A. As the pressurized carbon dioxide is supplied to the internal space of the first tank 22A, the internal space of the first tank 22A is pressurized and the carbon dioxide is compressed. After the first tank 22A is sufficiently filled with compressed carbon dioxide, the controller 51 closes the first tank opening / closing valve 20A. By closing the first tank opening / closing valve 20A, the carbon dioxide is stored in the first tank 22A.

[0037] A concentration sensor that detects the carbon dioxide concentration of the exhaust gas that has passed through the MOF may be disposed downstream of the container 16 in the treatment line 15. When switching between the first state and the second state, the controller 51 may determine the timing of switching between the first state and the second state based on the detection data of the concentration sensor. For example, in the first state, when it is determined based on the detection data of the concentration sensor that the carbon dioxide concentration of the exhaust gas that has passed through the MOF is equal to or higher than a predetermined reference value, the controller 51 may switch from the first state to the second state.

[0038] [Effects] As described above, in the embodiment, the exhaust gas treatment device 10 includes a container 16 that contains an MOF capable of adsorbing carbon dioxide contained in exhaust gas, and a container compressor 13 that pressurizes the container 16 to which the exhaust gas is supplied.

[0039] According to the embodiment, carbon dioxide contained in the exhaust gas of the engine 8 is adsorbed by the MOF, which prevents the carbon dioxide contained in the exhaust gas from being emitted into the atmosphere. Because the amount of carbon dioxide emitted into the atmosphere is reduced, the work machine 1 can contribute to preventing global warming.

[0040] As explained with reference to Figure 4, MOFs adsorb carbon dioxide when pressurized and release carbon dioxide when depressurized. After carbon dioxide is adsorbed by the MOF, the MOF is depressurized, causing carbon dioxide to be released from the MOF. The carbon dioxide released from the MOF is stored in tank 22.

[0041] The exhaust gas treatment device 10 includes a cooler 12 that cools the exhaust gas before it is supplied to the vessel 16. As described above, if the temperature of the exhaust gas is equal to or higher than the upper heat resistance limit of the MOF, the adsorption performance of the MOF may be reduced. The cooler 12 cools the exhaust gas so that the temperature of the exhaust gas is equal to or lower than the upper heat resistance limit of the MOF. Cooling the exhaust gas by the cooler 12 suppresses a reduction in the adsorption performance of the MOF for carbon dioxide.

[0042] In this embodiment, the first container 16A and the second container 16B are arranged in parallel, and the switching valve 14 switches between a first state in which the exhaust gas is supplied to the first container 16A and a second state in which the exhaust gas is supplied to the second container 16B. By switching between the first state and the second state, for example, when the MOFs in the first container 16A can no longer adsorb all the carbon dioxide, the MOFs in the second container 16B can adsorb the carbon dioxide contained in the exhaust gas. By switching between the first state and the second state, the exhaust gas treatment device 10 can continue to recover carbon dioxide contained in the exhaust gas.

[0043] [Another Embodiment] Fig. 7 is a diagram showing an exhaust gas treatment device 100 according to another embodiment. Note that components such as the switching valve 14 and the tank 22 are omitted from Fig. 7 . As shown in Fig. 7 , a first container 161, a second container 162, and a third container 163 may be arranged in series in the treatment line 15. The first container 161 includes a first container 161A arranged in the first treatment line 15A and a first container 161B arranged in the second treatment line 15B. The second container 162 includes a second container 162A arranged in the first treatment line 15A and a second container 162B arranged in the second treatment line 15B. The third container 163 includes a third container 163A arranged in the first treatment line 15A and a third container 163B arranged in the second treatment line 15B.

[0044] The first container 161 contains a first MOF capable of adsorbing a first substance contained in the exhaust gas. The second container 162 contains a second MOF capable of adsorbing a second substance contained in the exhaust gas. The third container 163 contains a third MOF capable of adsorbing a third substance contained in the exhaust gas. As an example, the first substance may be carbon dioxide (CO ２ The second substance is carbon monoxide (CO). The third substance is nitrogen compounds (NOx).

[0045] As described above, MOFs can adsorb only specific substances by combining metal ions and organic molecules. The adsorption performance of the first MOF for the first substance is higher than that of the second MOF and the third MOF. The adsorption performance of the second MOF for the second substance is higher than that of the third MOF and the first MOF. The adsorption performance of the third MOF for the third substance is higher than that of the first MOF and the second MOF.

[0046] By arranging the first container 161, the second container 162, and the third container 163 in series, the exhaust gas treatment device 100 can recover multiple types of substances contained in the exhaust gas. Therefore, the work machine 1 can contribute to preventing global warming and air pollution.

[0047] If the engine 8 can use multiple fuels, the types or proportions of substances contained in the exhaust gas may vary depending on the fuel. Examples of fuels include diesel, hydrogen, ammonia, and carbon-neutral fuel. Examples of carbon-neutral fuels include fatty acid methyl ester (FAME), hydrotreated vegetable oil (HVO), e-fuel, and gas-to-liquids (GTL) fuel. If the types or proportions of substances contained in the exhaust gas vary depending on the fuel, the MOF contained in the container 16 may be changed based on the fuel. For example, if the use of a first fuel generates exhaust gas containing a large amount of the first substance, a first MOF with high adsorption performance for the first substance may be employed, or multiple containers 16 containing the first MOF may be arranged in series. If the use of a second fuel generates exhaust gas containing a large amount of the second substance, a second MOF with high adsorption performance for the second substance may be employed, or multiple containers 16 containing the second MOF may be arranged in series.

[0048] In the example shown in FIG. 7 , the content of the first MOF, second MOF, and third MOF arranged in the first treatment line 15A may be different from the content of the first MOF, second MOF, and third MOF arranged in the second treatment line 15B. A fuel sensor capable of detecting the type of carbon-neutral fuel may be provided. The fuel sensor detects the type of carbon-neutral fuel before the carbon-neutral fuel is supplied to the engine 8. The controller 51 can identify the carbon-neutral fuel supplied to the engine 8 based on the detection data of the fuel sensor. The controller 51 may determine whether the exhaust gas from the engine 8 is to flow through the first treatment line 15A or the second treatment line 15B based on the detection data of the fuel sensor.

[0049] REFERENCE SIGNS LIST 1...work machine, 2...body, 3...traveling device, 4...working machine, 5...wheel, 6...boom, 7...bucket, 8...engine, 10...exhaust gas treatment device, 11...exhaust gas line, 12...cooler, 13...container compressor, 14...switching valve, 15...treatment line, 15A...first treatment line, 15B...second treatment line, 16...container, 16A...first container, 16B...second container, 17...pressure reducer, 17A...first pressure reducer, 17B...second pressure reducer, 18...discharge on / off valve, 18A...first discharge on / off valve, 18B...second discharge on / off valve, 19...tank line, 19A...first tank line, 19B...second tank line, 20...tank on / off valve, 20A ...first tank on-off valve, 20B...second tank on-off valve, 21...tank compressor, 21A...first tank compressor, 21B...second tank compressor, 22...tank, 22A...first tank, 22B...second tank, 23...pressure sensor, 23A...first pressure sensor, 23B...second pressure sensor, 51...controller, 52...processor, 53...storage device, 54...input / output interface, 100...exhaust gas treatment device, 161...first container, 161A...first container, 161B...first container, 162...second container, 162A...second container, 162B...second container, 163...third container, 163A...third container, 163B...third container.

Claims

1. An exhaust gas treatment device for an engine mounted on a work machine, comprising: a container that contains a metal organic framework capable of adsorbing at least one substance contained in exhaust gas; and a compressor that pressurizes the container to which the exhaust gas is supplied.

2. The exhaust gas treatment device according to claim 1, comprising: a pressure reducer that reduces the pressure in the container; and a tank that is connected to the container and that stores the substance released from the metal organic framework by the reduced pressure.

3. The exhaust gas treatment device according to claim 2, further comprising a controller for controlling the compressor and the pressure reducer, wherein the controller increases the pressure in the container so that the pressure is equal to or greater than a specified value, and then reduces the pressure so that the pressure is less than the specified value.

4. The exhaust gas treatment device according to claim 2, wherein the containers include a first container and a second container; a switching valve that switches between a first state in which the exhaust gas is supplied to the first container and a second state in which the exhaust gas is supplied to the second container; and a controller that controls the compressor, the pressure reducer, and the switching valve, wherein the controller: in the first state, pressurizes the first container to which the exhaust gas is supplied and depressurizes the second container; and in the second state, pressurizes the second container to which the exhaust gas is supplied and depressurizes the first container.

5. The exhaust gas treatment device according to claim 1, wherein the container includes a first container and a second container, a first metal-organic framework capable of adsorbing a first substance contained in the exhaust gas is accommodated in the first container, and a second metal-organic framework capable of adsorbing a second substance contained in the exhaust gas is accommodated in the second container.

6. The exhaust gas treatment device according to claim 1, further comprising a cooler that cools the exhaust gas supplied to the container.

7. A method for treating exhaust gas from an engine mounted on a working machine, comprising: cooling exhaust gas; pressurizing a container to which the cooled exhaust gas is supplied and which contains a metal organic framework capable of adsorbing at least one substance contained in the exhaust gas; depressurizing the container after the substance is adsorbed by the metal organic framework; and storing the substance released from the metal organic framework by the depressurization in a tank.

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