Exhaust emission control system

Abstract

To provide an exhaust emission control system capable of reducing electric power consumption.SOLUTION: An exhaust emission control system includes: a plurality of adsorption / desorption sections 210 (adsorption parts) that can adsorb carbon dioxide and nitrogen oxide included in exhaust gas; and a guide section (route L12) that can guide exhaust gas that has passed through one adsorption / desorption section 210 (adsorption / desorption part 210B) of the plurality of adsorption / desorption sections 210 to another adsorption / desorption section 210 (adsorption / desorption part 210D) so as to regulate a temperature of the other adsorption / desorption section 210D.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for an exhaust gas purification system for purifying exhaust gas. [Background technology]

[0002] Conventionally, the technology of an exhaust gas purification system for purifying exhaust gas has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a carbon dioxide separation and capture system equipped with an adsorption and desorption module capable of adsorbing and desorbing carbon dioxide contained in a target gas such as exhaust gas. In this separation and capture system, in the adsorption step, the cooled target gas is supplied to the adsorption and desorption module, so that carbon dioxide can be separated from the target gas and adsorbed by the adsorbent. In the desorption step, the adsorbent is heated to a desorption temperature higher than the adsorption temperature, so that the carbon dioxide adsorbed by the adsorbent can be captured.

[0004] When carbon dioxide is adsorbed onto the adsorbent, the adsorption / desorption module needs to be cooled to a predetermined temperature. However, in order to cool the target gas, etc., power is required to operate various devices (e.g., refrigeration cycle compressors, etc.), so technology that can reduce this power consumption is desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-159816 A Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect of the present disclosure has been made in consideration of the above-mentioned circumstances, and a problem to be solved by the present disclosure is to provide an exhaust gas purification system that is capable of reducing power consumption. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0008] An exhaust gas purification system according to one embodiment of the present disclosure includes a plurality of adsorption sections capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas, and a guide section capable of guiding exhaust gas that has passed through one of the plurality of adsorption sections to another adsorption section, thereby adjusting the temperature of the other adsorption section.

[0009] In addition, the multiple adsorption sections are switchable between a first state in which they adsorb carbon dioxide and nitrogen oxides, and a second state in which they are pre-cooled before reaching the first state, and the guide section guides the exhaust gas that has passed through the adsorption sections in the first state to the adsorption sections in the second state.

[0010] The exhaust gas purification system also includes a cooling section that cools at least one of the adsorption section in the first state and the adsorption section in the second state by using a first refrigerant in a liquid phase.

[0011] The exhaust gas purification system also includes a reduction section capable of performing reduction of nitrogen oxides in the adsorption section by using urea or a hydrocarbon as a reducing agent. Effect of the Invention

[0012] According to one aspect of the present disclosure, it is possible to reduce power consumption. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a configuration of an exhaust gas purification system according to an embodiment of the present disclosure; [Diagram 2] FIG. 6 is a schematic diagram showing a configuration of an exhaust gas purification system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] First, the configuration of an exhaust gas purification system 4 according to one aspect (embodiment) of the present disclosure will be described with reference to FIG.

[0015] The exhaust gas purification system 4 purifies carbon dioxide (CO2) and nitrogen oxides (NOx) contained in the exhaust gas. In this embodiment, an exhaust gas purification system 4 that purifies the exhaust gas discharged from the engine E will be described as an example. The exhaust gas purification system 4 mainly includes an adsorption / desorption section 210, a cooling section 220, an auxiliary cooling section 230, a storage section 240, a heating device 250, a control section 260, and the like.

[0016] The adsorption / desorption unit 210 adsorbs carbon dioxide (CO2) and nitrogen oxides (NOx) contained in the exhaust gas. The adsorption / desorption unit 210 is provided with a zeolite-based adsorbent such as Cu-ZSM-5. The zeolite-based adsorbent is a porous material, and the size of the pores affects the carbon dioxide absorption capacity, as described below. In addition, the metal supported by the zeolite-based adsorbent affects its performance as an SCR catalyst, as described below.

[0017] FIG. 1 illustrates the adsorption / desorption section 210 (adsorption / desorption section 210A on the upper and left side in the figure) in a state heated by waste heat of exhaust gas supplied by the first cooling section 221, the adsorption / desorption section 210 (adsorption / desorption section 210B on the lower and right side in the figure) in a state cooled by the refrigerant of the second cooling section 222, the adsorption / desorption section 210 (adsorption / desorption section 210C on the upper and right side in the figure) in a state heated (preheated) by the refrigerant that has passed through the adsorption / desorption section 210A, and the adsorption / desorption section 210 (adsorption / desorption section 210D) in a state cooled (precooled) by the refrigerant of the second cooling section 222 and the exhaust gas that has passed through the adsorption / desorption section 210B.

[0018] In this manner, the exhaust gas purification system 4 according to this embodiment includes a plurality of (four) adsorption / desorption units 210, and when one adsorption / desorption unit 210A is heated, another adsorption / desorption unit 210C is preheated, and when another adsorption / desorption unit 210B is adsorbing carbon dioxide or the like, another adsorption / desorption unit 210D is precooled, and so on. In this manner, the processes by each adsorption / desorption unit 210 can be performed in parallel. Furthermore, by appropriately switching the flow paths of the exhaust gas, the refrigerant, and the like, the state of each adsorption / desorption unit 210 (adsorption / desorption units 210A to 210D) can be arbitrarily switched. For example, each adsorption / desorption unit 210 can be switched in the following order: a state in which carbon dioxide or the like is adsorbed (adsorption / desorption unit 210B), a preheated state (adsorption / desorption unit 210C), a state in which carbon dioxide is desorbed by heating (adsorption / desorption unit 210A), and a precooled state (adsorption / desorption unit 210D). By sequentially switching the state of each adsorption / desorption unit 210 in this manner, it is possible to sequentially perform adsorption and desorption of carbon dioxide and the like, reduction of nitrogen oxides, and the like in each adsorption / desorption unit 210.

[0019] In addition to the above four states, when reducing the nitrogen oxides adsorbed in the adsorption / desorption section 210, the adsorption / desorption section 210 can be temporarily heated to a temperature higher than the state in which carbon dioxide is desorbed (adsorption / desorption section 210A). By supplying a reducing agent together with exhaust gas to the adsorption / desorption section 210 in this state (in this embodiment, adsorption / desorption section 210B), the nitrogen oxides adsorbed in the adsorption / desorption section 210 can be reduced.

[0020] Specifically, exhaust gas from the engine E is guided to the adsorption / desorption section 210 (adsorption / desorption section 210B) via a path L11 formed of piping or the like. A reducing agent can be injected from an injection device 211 into the exhaust gas supplied to the adsorption / desorption section 210B via the path L11. As the reducing agent, urea or hydrocarbon can be used. For example, when urea is used as the reducing agent, urea water stored in a tank can be injected by the injection device 211. The injected urea water is thermally decomposed by the waste heat of the exhaust gas, and ammonia is generated. This ammonia acts as a reducing agent. When hydrocarbons are used as the reducing agent, hydrocarbons generated by decomposition of diesel fuel can be used. Furthermore, the exhaust gas whose temperature has been reduced by passing through the adsorption / desorption section 210B is supplied to the adsorption / desorption section 210D via a path L12, and the adsorption / desorption section 210D can be cooled. The exhaust gas that has cooled the adsorption / desorption section 210D is then discharged to the outside via a path L13.

[0021] The cooling section 220 uses a refrigerant to cool the exhaust gas and each section of the exhaust gas purification system 4. The cooling section 220 mainly includes a first cooling section 221, a second cooling section 222, a third cooling section 223, an auxiliary cooling section 230, and the like. Note that the first cooling section 221, the second cooling section 222, and the third cooling section 223 share a part of the same refrigerant flow path. As a result, a common refrigerant is circulated in the first cooling section 221, the second cooling section 222, and the third cooling section 223 using a common pump 221c. This will be described in detail below.

[0022] The first cooling section 221 uses a refrigerant to cool the exhaust gas discharged from the engine E, and also uses waste heat from the exhaust gas to heat the adsorption / desorption section 210. As the refrigerant, for example, a liquid phase fluid (e.g., cooling water or oil) having a relatively large heat capacity can be used. The first cooling section 221 mainly includes a circulation path L21, a heat exchanger 221a, a radiator 221b, and a pump 221c.

[0023] The circulation path L21 is configured by piping or the like, and allows the refrigerant to flow through it. The circulation path L21 is formed so as to sequentially connect the heat exchanger 221a, the adsorption / desorption unit 210A, the adsorption / desorption unit 210C, the radiator 221b, the auxiliary cooling unit 230, and the pump 221c.

[0024] The heat exchanger 221a is provided in the middle of the path L11. The heat exchanger 221a exchanges heat between the exhaust gas discharged from the engine E and the refrigerant, and can lower the temperature of the exhaust gas. The refrigerant that has received the heat of the exhaust gas in the heat exchanger 221a is supplied to the adsorption / desorption section 210 (adsorption / desorption section 210A). This makes it possible to heat the adsorption / desorption section 210A. By heating the adsorption / desorption section 210A, the carbon dioxide adsorbed in the adsorption / desorption section 210A can be desorbed.

[0025] The refrigerant that has passed through the adsorption / desorption unit 210A is further supplied to the adsorption / desorption unit 210C. This allows the adsorption / desorption unit 210C to be preheated. The preheated adsorption / desorption unit 210C is later switched to the adsorption / desorption unit 210A by switching the flow path of the refrigerant, etc. The refrigerant that has passed through the adsorption / desorption unit 210C is dissipated heat by the radiator 221b, and then supplied to the pump 221c via the auxiliary cooling unit 230 described below. The refrigerant supplied to the pump 221c is supplied again to the heat exchanger 221a by the pump 221c.

[0026] In this manner, the first cooling section 221 can cool the exhaust gas by circulating the refrigerant, and can also heat the adsorption / desorption section 210 by utilizing the waste heat of the exhaust gas.

[0027] The second cooling section 222 is for cooling the adsorption / desorption section 210B and the adsorption / desorption section 210D using a refrigerant. The second cooling section 222 mainly includes a circulation path L22, a radiator 221b, a pump 221c, and the like. The second cooling section 222 uses the same refrigerant as the first cooling section 221. The second cooling section 222 also uses the radiator 221b and the pump 221c that are also used by the first cooling section 221.

[0028] The circulation path L22 is configured by piping or the like, and allows the refrigerant to flow. The circulation path L22 is formed to sequentially connect the adsorption / desorption section 210B, the adsorption / desorption section 210D, the radiator 221b, the auxiliary cooling section 230, and the pump 221c. The circulation path L22 is formed to branch from a branch point P1 formed downstream of the pump 221c in the circulation path L21, and a branch point P2 formed between the adsorption / desorption section 210C and the radiator 221b. In this way, a part of the circulation path L21 of the first cooling section 221 (a part between the branch point P1 and the branch point P2) constitutes a part of the circulation path L22 of the second cooling section 222. The circulation path L22 branches at a branch point P3 provided upstream of the adsorption / desorption section 210B and the adsorption / desorption section 210D, and is connected to the adsorption / desorption section 210B and the adsorption / desorption section 210D, respectively. The circulation path L21 branched off at the branch point P3 joins again at a branch point P4 provided downstream of the adsorption / desorption section 210B and the adsorption / desorption section 210D.

[0029] In the second cooling section 222, the refrigerant pumped from the pump 221c is supplied to the adsorption / desorption section 210B and the adsorption / desorption section 210D via the branching section P1 and the branching section P3. This allows the adsorption / desorption section 210B and the adsorption / desorption section 210D to be cooled. The refrigerant that has passed through the adsorption / desorption section 210B and the adsorption / desorption section 210D is supplied to the radiator 221b via the branching section P4 and the branching section P2. The refrigerant whose temperature has increased due to the heat of the adsorption / desorption section 210B and the adsorption / desorption section 210D is dissipated by the radiator 221b, and then is supplied to the pump 221c via the auxiliary cooling section 230. The refrigerant supplied to the pump 221c is supplied again to the adsorption / desorption section 210B and the adsorption / desorption section 210D by the pump 221c.

[0030] In this manner, the second cooling section 222 can cool the adsorption / desorption section 210B and the adsorption / desorption section 210D by circulating the refrigerant.

[0031] The third cooling section 223 uses a refrigerant to cool carbon dioxide to be supplied to the storage section 240 described below. The third cooling section 223 mainly includes a circulation path L23, a heat exchanger 223a, a radiator 221b, and a pump 221c. The third cooling section 223 uses the same refrigerant as the first cooling section 221 and the second cooling section 222. The third cooling section 223 also uses the radiator 221b and the pump 221c which are also used by the first cooling section 221 and the second cooling section 222.

[0032] The circulation path L23 is composed of piping or the like, and allows the refrigerant to flow. The circulation path L23 is formed to sequentially connect the heat exchanger 223a, the radiator 221b, the auxiliary cooling unit 230, and the pump 221c. The circulation path L23 is formed to branch off from a branch point P1 formed downstream of the pump 221c in the circulation path L22, and a branch point P5 formed between the adsorption / desorption unit 210B and the branch point P4 in the circulation path L22. In this way, a part of the circulation path L22 of the second cooling unit 222 (a part from the branch point P5 through the branch point P4 and the branch point P2 to the branch point P1) constitutes a part of the circulation path L23 of the third cooling unit 223.

[0033] The heat exchanger 223a is provided in the middle of the circulation path L22 (downstream of the branching point P1). The heat exchanger 223a exchanges heat between the carbon dioxide supplied to the storage section 240 (described later) and the refrigerant flowing through the circulation path L23, and can lower the temperature of the carbon dioxide. The refrigerant that has received the heat of the carbon dioxide in the heat exchanger 223a is dissipated in the radiator 221b, and is then supplied to the pump 221c via the auxiliary cooling section 230. The refrigerant supplied to the pump 221c is supplied again to the heat exchanger 223a by the pump 221c.

[0034] In this manner, the third cooling section 223 can cool the carbon dioxide supplied to the storage section 240 by circulating the refrigerant.

[0035] The auxiliary cooling section 230 is for auxiliary cooling the refrigerant used in the cooling section 220 (the first cooling section 221, the second cooling section 222, and the third cooling section 223). The auxiliary cooling section 230 is a refrigeration cycle that performs cooling by causing a phase change of an appropriate refrigerant (such as carbon dioxide). The auxiliary cooling section 230 mainly includes a heat exchanger 231, a compressor 232, a condenser 233, an expansion valve 234, and the like.

[0036] The heat exchanger 231 is disposed between the radiator 221b and the pump 221c on the refrigerant flow path (circulation path L21, etc.). The heat exchanger 231 exchanges heat with the refrigerant flowing through the path, and can further lower the temperature of the refrigerant cooled by the radiator 221b. The refrigerant such as carbon dioxide used for the heat exchange in the heat exchanger 231 is compressed by the compressor 232, and then dissipates heat in the condenser 233. The refrigerant that has dissipated heat in the condenser 233 can be supplied again to the heat exchanger 231 via the expansion valve 234.

[0037] For example, when the cooling capacity of the cooling section 220 is insufficient with only the radiator 221b (such as when it is necessary to cool the exhaust gas from the engine E to a temperature lower than the outside air temperature), the auxiliary cooling section 230 configured as described above can be operated to further cool the refrigerant in the cooling section 220, thereby improving the cooling capacity.

[0038] The storage section 240 stores the carbon dioxide desorbed from the adsorption / desorption section 210A. The storage section 240 is connected to the adsorption / desorption section 210A via a path L14 configured by piping or the like. A compressor 241 and a heat exchanger 223a are provided in the middle of the path L14. The carbon dioxide desorbed from the adsorption / desorption section 210A is compressed by the compressor 241, has heat dissipated by the heat exchanger 223a, and is stored in the storage section 240.

[0039] The heating device 250 is a device for heating the adsorption / desorption unit 210. The heating device 250 can be configured with, for example, an electric heating wire. The temperature of the adsorption / desorption unit 210 can be detected by a temperature sensor 251. By controlling the operation of the heating device 250 and the like while detecting the temperature of the adsorption / desorption unit 210 with the temperature sensor 251, the temperature of the adsorption / desorption unit 210 can be adjusted to an arbitrary temperature.

[0040] The control unit 260 controls the operation of the exhaust gas purification system 4. The control unit 260 is composed of an arithmetic processing device such as a CPU, and a storage device such as a RAM, a ROM, and a HDD. The control unit 260 can receive the detection result of the temperature sensor 251. The control unit 260 can also control the heating device 250. However, the control unit 260 is not limited to this and can also control the operation of each part of the exhaust gas purification system 4.

[0041] Although detailed explanation is omitted, the flow path of the fluid in the exhaust gas purification system 4 (for example, carbon dioxide adsorbed and desorbed in the adsorption / desorption section 210) can be arbitrarily switched using a switching device (piping, switching valve, etc.) not shown.

[0042] The exhaust gas purification system 4 configured in this manner can be used to purify carbon dioxide and nitrogen oxides contained in the exhaust gas discharged from the engine E. A specific description will be given below.

[0043] First, the purification of carbon dioxide and nitrogen oxides contained in exhaust gas will be described.

[0044] In this case, the exhaust gas discharged from the engine E is cooled to a predetermined first temperature T1 (for example, about the outside air temperature (25 degrees)) by the first cooling section 221 while flowing through the path L11. The cooled exhaust gas is supplied to the adsorption / desorption section 210B, and carbon dioxide and nitrogen oxides in the exhaust gas are adsorbed by the adsorbent. In this way, by cooling the exhaust gas supplied to the adsorption / desorption section 210B by the first cooling section 221, the carbon dioxide and nitrogen oxides in the exhaust gas can be efficiently adsorbed.

[0045] If further cooling of the exhaust gas is required (if it is desired to lower the exhaust gas temperature below the outside air temperature), the auxiliary cooling unit 230 is operated. When the auxiliary cooling unit 230 is operated, the refrigeration cycle of the auxiliary cooling unit 230 lowers the temperature of the refrigerant in the cooling unit 220, and the exhaust gas can be cooled to an even lower temperature. For example, by cooling the exhaust gas to about 0 degrees, the moisture in the exhaust gas can also be effectively removed.

[0046] The exhaust gas in which carbon dioxide and nitrogen oxides have been adsorbed in the adsorption / desorption section 210B is supplied to the adsorption / desorption section 210D via path L12. As a result, the adsorption / desorption section 210D can be cooled using the exhaust gas that has been cooled while flowing through the adsorption / desorption section 210B. In this manner, in this embodiment, the adsorption / desorption section 210D can be cooled (pre-cooled) using the exhaust gas that has flowed through the adsorption / desorption section 210B in addition to the second cooling section 222. As a result, the power consumption of the second cooling section 222 can be reduced. The exhaust gas that has passed through the adsorption / desorption section 210D is discharged to the outside via path L13.

[0047] Next, the case where the carbon dioxide adsorbed in the adsorption / desorption unit 210 is desorbed will be described.

[0048] In this case, waste heat of the exhaust gas recovered by the heat exchanger 221a of the first cooling section 221 is supplied to the adsorption / desorption section 210A via the refrigerant, and the adsorption / desorption section 210A is heated to a temperature higher than the first temperature T1. The adsorption / desorption section 210A is heated to a predetermined second temperature T2 (for example, about 150 degrees) at which carbon dioxide can be desorbed. At this time, the adsorption / desorption section 210 can also be heated using the heating device 250. This causes carbon dioxide to be desorbed from the adsorption / desorption section 210A. The carbon dioxide released from the adsorption / desorption section 210A is stored in the storage section 240 via a path L14.

[0049] Next, the case where the nitrogen oxides adsorbed in the adsorption / desorption unit 210 are reduced will be described.

[0050] In this case, the adsorption / desorption unit 210B is heated to a temperature higher than the second temperature T2 when carbon dioxide is desorbed. The adsorption / desorption unit 210 is heated to a predetermined third temperature T3 (for example, about 400 degrees) at which the adsorption / desorption unit 210 can function as an SCR catalyst. For this heating, first, waste heat of the exhaust gas recovered by the heat exchanger 221a of the first cooling unit 221 is used. The adsorption / desorption unit 210A and the adsorption / desorption unit 210C can be heated by this waste heat. If this waste heat is not sufficient, the heating device 250 is operated to heat the adsorption / desorption unit 210 to the target temperature. The heated adsorption / desorption unit 210A and the adsorption / desorption unit 210C are switched to the adsorption / desorption unit 210B.

[0051] A reducing agent is sprayed onto the exhaust gas supplied to the adsorption / desorption section 210B via the path L11. The exhaust gas passes through the adsorption / desorption section 210B, whereby the nitrogen oxides adsorbed in the adsorption / desorption section 210B are reduced. The exhaust gas that has passed through the adsorption / desorption section 210B is discharged to the outside via the path L12 and the path L13.

[0052] The temperature of the adsorption / desorption section 210 and the flow paths of the fluids in each section can be switched by the control section 260. By switching the temperature of the adsorption / desorption section 210 to any one of the first temperature T1, the second temperature T2, and the third temperature T3 by the control section 260 and appropriately injecting a reducing agent from the injection device 211, it is possible to perform adsorption of carbon dioxide and nitrogen oxides, desorption of carbon dioxide, and reduction of nitrogen oxides using the common adsorption / desorption section 210. This eliminates the need to separately provide a purification device for purifying carbon dioxide and a purification device for purifying nitrogen oxides, and therefore simplifies the configuration of the exhaust gas purification system 4.

[0053] In this embodiment, the exhaust gas and the adsorption / desorption unit 210 are cooled by the cooling unit 220 that mainly uses a liquid-phase refrigerant. This makes it possible to reduce the use of equipment that consumes a large amount of power (such as a compressor). In addition, when the cooling capacity is insufficient, the auxiliary cooling unit 230 can be used to temporarily improve the cooling capacity.

[0054] As described above, the exhaust gas purification system 4 according to one embodiment of the present disclosure has the following features: an adsorption / desorption unit 210 (adsorption unit) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a cooling section 220 that cools at least one of the exhaust gas guided to the adsorption / desorption section 210 and the adsorption section using a first liquid refrigerant; It is equipped with the following. With this configuration, it is possible to reduce power consumption. That is, since cooling is performed without using a cooling system (such as a refrigeration cycle) that involves a phase change of the refrigerant, the equipment used in the refrigeration cycle (such as a compressor) is not necessary, and power consumption can be reduced. In particular, by using a liquid-phase refrigerant with a relatively large heat capacity, it is possible to achieve stable cooling performance while reducing power consumption.

[0055] In addition, the cooling unit 220 is The radiator 221b is provided to radiate the heat of the first refrigerant. With this configuration, the first refrigerant can be cooled while relatively reducing power consumption.

[0056] In addition, the cooling unit 220 is The first cooling section 221 cools the exhaust gas guided to the adsorption / desorption section 210 . With this configuration, carbon dioxide and nitrogen oxides can be adsorbed efficiently.

[0057] In addition, the cooling unit 220 is The cooling device includes a secondary cooling section 222 for cooling the adsorption / desorption section 210 . With this configuration, carbon dioxide and nitrogen oxides can be adsorbed efficiently.

[0058] In addition, the cooling unit 220 is The third cooling section 223 cools the carbon dioxide desorbed from the adsorption / desorption section 210 . With this configuration, the cooling section 220 for cooling the exhaust gas and the adsorption / desorption section 210 can also be used to cool the captured carbon dioxide, simplifying the system configuration. Also, by cooling the captured carbon dioxide, the volume of the carbon dioxide can be reduced, allowing for efficient capture.

[0059] In addition, the exhaust gas purification system 4 is The cooling unit 220 includes an auxiliary cooling unit 230 capable of cooling the first refrigerant used in the cooling unit 220 by using a second refrigerant that undergoes a phase change. By configuring in this manner, when the cooling capacity of the cooling section 220 is insufficient (for example, when it is desired to cool the exhaust gas to a temperature lower than the outside air temperature), the auxiliary cooling section 230 can be operated to improve the cooling capacity.

[0060] In addition, the exhaust gas purification system 4 is The fuel cell includes an injection device 211 (reduction section) capable of reducing nitrogen oxides in the adsorption / desorption section 210 by using urea or a hydrocarbon as a reducing agent. With this configuration, the nitrogen oxides adsorbed in the adsorption / desorption section 210 can be reduced (purified), and the decrease in the adsorption capacity of the adsorption / desorption section 210 can be suppressed.

[0061] In addition, the exhaust gas purification system 4 according to one embodiment of the present disclosure includes: an adsorption / desorption unit 210 (adsorption unit) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; A cooling section 220 that cools at least one of the exhaust gas guided to the adsorption / desorption section 210, the adsorption section, or the carbon dioxide desorbed from the adsorption section using a liquid-phase first refrigerant; It is equipped with the following. With this configuration, it is possible to reduce power consumption.

[0062] As described above, the exhaust gas purification system 4 according to one embodiment of the present disclosure has the following features: A plurality of adsorption / desorption units 210 (adsorption units) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a guide section (path L12) capable of guiding exhaust gas that has passed through one adsorption / desorption section 210 (adsorption / desorption section 210B) of the plurality of adsorption / desorption sections 210 to another adsorption / desorption section 210 (adsorption / desorption section 210D), thereby adjusting the temperature of the other adsorption / desorption section 210D; It is equipped with the following. Such a configuration can reduce power consumption. That is, the exhaust gas that has passed through the adsorption / desorption section 210B can be used to adjust the temperature of the other adsorption / desorption section 210D (cooling in the embodiment of the present disclosure), so that the power consumption of the second cooling section 222 for cooling the adsorption / desorption section 210D can be reduced.

[0063] In addition, the plurality of adsorption / desorption units 210 are It is switchable between a first state (adsorption / desorption section 210B) in which carbon dioxide and nitrogen oxides are adsorbed, and a second state (adsorption / desorption section 210D) in which the first state is pre-cooled, The guide section (path L12) is The exhaust gas that has passed through the adsorption / desorption section 210B in the first state is guided to the adsorption / desorption section 210D in the second state. Such a configuration can reduce power consumption. That is, since the adsorption / desorption unit 210D can be pre-cooled using the cold energy of the exhaust gas that has passed through the adsorption / desorption unit 210B, the power consumption of the secondary cooling unit 222 for cooling the adsorption / desorption unit 210D can be reduced.

[0064] In addition, the exhaust gas purification system 4 is The cooling unit 222 includes a second cooling unit 222 (cooling unit) that cools at least one of the adsorption / desorption unit 210B in the first state or the adsorption / desorption unit 210D in the second state by using a first refrigerant in a liquid phase. This configuration makes it possible to reduce power consumption. In other words, since cooling is performed without using a cooling system (such as a refrigeration cycle) that involves a phase change of the refrigerant, equipment used in a refrigeration cycle (such as a compressor) is not required, and power consumption can be reduced.

[0065] In addition, the exhaust gas purification system 4 is The fuel cell includes an injection device 211 (reduction section) capable of reducing nitrogen oxides in the adsorption / desorption section 210 by using urea or a hydrocarbon as a reducing agent. With this configuration, the nitrogen oxides adsorbed in the adsorption / desorption section 210 can be reduced (purified), and the decrease in the adsorption capacity of the adsorption / desorption section 210 can be suppressed.

[0066] The adsorption / desorption unit 210 according to this embodiment is one embodiment of the adsorption unit according to the present invention. Moreover, the injection device 211 according to this embodiment is one embodiment of the reduction section according to the present invention. Moreover, the path L12 according to this embodiment is one embodiment of a guide section according to the present invention.

[0067] Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0068] For example, the exhaust gas purification system 4 according to the above embodiment can be mounted on vehicles such as trucks and tractors. The exhaust gas purification system 4 can also be mounted on other work vehicles, agricultural vehicles, industrial vehicles, transport equipment, and the like.

[0069] In addition, the exhaust gas purification system 4 and the like according to the above embodiment have been described as purifying the exhaust gas discharged from the engine E, but the present invention is not limited to this and can be used for any purpose. For example, it is possible to purify exhaust gas discharged from boilers and gas turbines of thermal power plants and the like, and exhaust gas generated in steelworks and the like.

[0070] As described above, it is also possible to provide a plurality of adsorption / desorption sections 210, and configure the system so that some of the adsorption / desorption sections 210 adsorb carbon dioxide and the like, and in parallel with this, the other adsorption / desorption sections 210 desorb carbon dioxide. With this configuration, exhaust gas can be purified efficiently.

[0071] In addition, in the above embodiment, an example in which four adsorption / desorption units 210 are used has been shown, but the present invention is not limited to this, and the number of adsorption / desorption units 210 can be changed as desired. For example, it is also possible to configure the exhaust gas purification system 4 using a single adsorption / desorption unit 210.

[0072] Furthermore, the first temperature T1, the second temperature T2, and the third temperature T3 described in the above embodiment are not particularly limited, and can be changed appropriately depending on the processing contents.

[0073] In the above embodiment, an example has been shown in which the cooling section 220 includes the first cooling section 221, the second cooling section 222, and the third cooling section 223, but the present invention is not limited to this, and the cooling section 220 may include at least one of the first cooling section 221, the second cooling section 222, and the third cooling section 223. For example, when cooling carbon dioxide to be recovered to the storage section 240, a relatively small cooling capacity does not pose a problem, so that the cooling section 220 may be configured to include only the third cooling section 223, thereby making it possible to reduce power consumption.

[0074] In the above embodiment, the first cooling section 221, the second cooling section 222, and the third cooling section 223 share some of their paths, and thus share the radiator 221b, the pump 221c, the refrigerant, and the like, but the present invention is not limited to this. For example, the first cooling section 221, the second cooling section 222, and the third cooling section 223 may each be configured independently.

[0075] In the above embodiment, the exhaust gas that has passed through the adsorption / desorption section 210B is used to cool (pre-cool) the adsorption / desorption section 210D, but the present invention is not limited to this, and it is sufficient that the exhaust gas that has passed through one adsorption / desorption section 210 is used to adjust the temperature of the other adsorption / desorption section 210. For example, it is also possible to use the exhaust gas to heat the other adsorption / desorption section 210 instead of cooling it.

[0076] In the above embodiment, the two adsorption / desorption units 210 (the adsorption / desorption unit 210A and the adsorption / desorption unit 210C) to be heated are connected in series by the circulation path L21, but the present invention is not limited to this. That is, the adsorption / desorption unit 210A and the adsorption / desorption unit 210C can also be connected in parallel using a branched path.

[0077] In the above embodiment, the two adsorption / desorption units 210 (the adsorption / desorption unit 210B and the adsorption / desorption unit 210D) to be cooled are connected in parallel by a branched circulation path L21, but the present invention is not limited to this. That is, as shown in Fig. 2, the adsorption / desorption unit 210B and the adsorption / desorption unit 210D can also be connected in series using a path that does not branch.

[0078] In this way, the multiple adsorption / desorption units 210 can be connected in series or in parallel. Also, a configuration in which it is possible to arbitrarily switch between series and parallel using a switching mechanism (switching valve, etc.) capable of switching the flow path of the refrigerant may be used. The switching between series and parallel can be performed, for example, according to the required cooling capacity. Also, for example, when multiple adsorption / desorption units 210 are connected in series, the pump capacity required to send the same volume of refrigerant to the adsorption / desorption units 210 can be made smaller than when multiple adsorption / desorption units 210 are connected in parallel, so that power consumption can be reduced. Also, accordingly, the pump and paths (piping, etc.) can be made smaller and simpler, and space can be saved. [Explanation of symbols]

[0079] 4. Exhaust Gas Purification System 210 Adsorption / desorption part 220 Cooling section 221 First cooling section 221b Radiator 222 Second cooling section 223 Third cooling section L12 Pathway

Claims

1. A plurality of adsorption sections capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a guide section capable of guiding exhaust gas that has passed through one of the plurality of adsorption sections to another adsorption section, thereby adjusting a temperature of the other adsorption section; An exhaust gas purification system comprising:

2. The plurality of suction portions include The adsorbent is switchable between a first state in which carbon dioxide and nitrogen oxides are adsorbed and a second state in which the adsorbent is pre-cooled before entering the first state; The guide portion is The exhaust gas that has passed through the adsorption section in the first state is guided to the adsorption section in the second state. The exhaust gas purification system according to claim 1 .

3. A cooling unit is provided that cools at least one of the adsorption unit in the first state or the adsorption unit in the second state using a first refrigerant in a liquid phase. The exhaust gas purification system according to claim 2 .

4. The present invention further comprises a reduction unit capable of reducing nitrogen oxides in the adsorption unit by using urea or a hydrocarbon as a reducing agent. The exhaust gas purification system according to claim 1 .

Images