Co2 recovery system for on-vehicle engine

Abstract

To improve storage efficiency of CO2.SOLUTION: A CO2 recovery system S includes: a first adsorption device 27A disposed downstream of an exhaust catalyst 23; a second adsorption device 27B connected in parallel with the first adsorption device 27A; a gas storage tank 51 disposed downstream of the first and second adsorption devices 27A, 27B; and a flow passage switching device 5 that switches each of the first and second adsorption devices 27A, 27B between an adsorption state and a desorption state. The gas storage tank 51 includes a release port 51b for releasing CO2 containing gas flowing into the gas storage tank 51 to outside.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a CO2 capture system for an on-board engine. [Background technology]

[0002] For example, Patent Document 1 discloses a CO2 separation device for an internal combustion engine. This separation device includes first and second CO2 adsorbers, a gas storage tank disposed downstream of the first and second CO2 adsorbers, an upstream switching valve, and a downstream switching valve.

[0003] Here, the CO2 adsorber is provided with a predetermined adsorbent material that can adsorb and desorb CO2 depending on the temperature. The upstream switching valve and downstream switching valve switch the flow path structure connecting the first and second CO2 adsorber to the gas storage tank. By controlling the upstream switching valve and downstream switching valve, it is possible to alternately switch between the first and second CO2 adsorber, one of which adsorbs CO2 from the exhaust gas, and the other, which is connected to the gas storage tank and stores the desorbed CO2.

[0004] Patent Document 2 discloses an example of a carbon dioxide capture device. This device includes an adsorption tank containing a first adsorbent. Here, the first adsorbent is configured to adsorb carbon dioxide contained in exhaust gas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-118528 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-131921 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when the flow path structure is configured to be switched as described in Patent Document 1, the CO2 adsorbent alternates between one that allows exhaust gas to flow and adsorbs CO2 from the exhaust gas, and another that is separated from the exhaust gas flow and sends the desorbed CO2 to a gas storage tank.

[0007] In this case, exhaust gas was previously flowing through the CO2 absorber that sends the desorbed CO2 in. In this case, exhaust gas components other than CO2, such as nitrogen, remain in the part of the exhaust pipe that leads from the CO2 absorber to the gas storage tank.

[0008] Therefore, in addition to the CO2 desorbed from the CO2 absorber, nitrogen and other substances remaining in part of the exhaust pipe are also sent to the gas storage tank. The gas storage tank becomes pressurized by the amount of nitrogen and other substances sent. Because there is a limit to the maximum pressure of the gas storage tank, in order to keep it within that limit, it is necessary to sacrifice the amount of CO2 stored in the gas storage tank. This is inconvenient in terms of ensuring CO2 storage efficiency.

[0009] To address these problems, it is conceivable to incorporate an adsorbent capable of adsorbing nitrogen gas into the gas storage tank instead of the first adsorbent as described in Patent Document 2. However, such a solution is inconvenient in terms of the manufacturing cost of the gas storage tank, the layout of the adsorbent, etc.

[0010] The present disclosure has been made in view of the above points, and its purpose is to improve the storage efficiency of CO2. [Means for solving the problem]

[0011] A first aspect of the present disclosure relates to a CO2 capture system for an automotive engine, which is disposed between a cylinder of the automotive engine and the downstream end of an exhaust pipe, and which circulates exhaust gas discharged from the cylinder and captures CO2 in the exhaust gas.

[0012] According to the first aspect, the CO2 recovery system comprises: a first adsorption device arranged downstream of an exhaust catalyst and comprising a CO2 adsorbent that adsorbs CO2 in the exhaust gas at at least one of high pressure and low temperature and desorbs the adsorbed CO2 at at least one of low pressure and high temperature; a second adsorption device connected in parallel to the first adsorption device in the flow direction of the exhaust gas and comprising the CO2 adsorbent; a gas storage tank arranged downstream of the first and second adsorption devices, into which a CO2-containing gas containing CO2 desorbed from one of the first and second adsorption devices flows and which has the CO2 adsorbent built in; and a flow path switching device that switches the first and second adsorption devices between an adsorption state in which they are connected between the exhaust catalyst and the downstream end, and a desorption state in which they are disconnected from the exhaust catalyst and connected to the gas storage tank, and the gas storage tank has an outlet that releases the CO2-containing gas that has flowed into the gas storage tank to the outside of the gas storage tank.

[0013] According to the first aspect, the CO2-containing gas is appropriately released from the gas storage tank. As a result, the CO2 in the CO2-containing gas is adsorbed by a CO2 adsorbent built into the gas storage tank, while the other components in the CO2-containing gas are released from the gas storage tank. Since the CO2 is adsorbed by the CO2 adsorbent, the pressure inside the tank can be kept low. On the other hand, by releasing the other components, the pressure inside the tank can be suppressed as much as possible.

[0014] Thus, by combining the adsorption of CO2 onto the CO2 adsorbent and the suppression of pressure inside the tank as much as possible, it is possible to improve the CO2 storage efficiency.

[0015] Furthermore, according to a second aspect of the present disclosure, the CO2 capture system may include a first flow pipe connected to the outlet and through which the CO2-containing gas flowing out of the gas storage tank flows, a gas amount adjustment unit disposed in the first flow pipe and adjusting the amount of CO2-containing gas flowing out through the first flow pipe, and a controller for controlling the gas amount adjustment unit, wherein the controller may control the gas amount adjustment unit to cause a predetermined amount of the CO2-containing gas that has flowed into the gas storage tank from one of the first and second adsorption devices that has been set in the desorption state to flow out of the gas storage tank.

[0016] According to the second aspect, the CO2-containing gas is actively discharged to the outside of the tank via the gas amount regulator, thereby suppressing the pressure inside the tank as much as possible, thereby improving the CO2 storage efficiency.

[0017] Furthermore, according to a third aspect of the present disclosure, when desorbing CO2 from one of the first and second adsorption devices, the controller may calculate a sum of a volume of the exhaust pipe that is common to the adsorption state and the desorption state and a volume of one of the first and second adsorption devices that is in the desorption state, and control the gas amount adjustment unit so that the predetermined amount becomes the sum.

[0018] According to the third aspect, it is believed that components such as nitrogen, which originate from the exhaust gas that passed through during the adsorption state, remain in the exhaust pipe that is common to both the adsorption state and the desorption state and in the adsorption device that is connected to the exhaust pipe. Therefore, by controlling the gas amount regulator as in the third aspect, it is possible to accurately remove such remaining components.

[0019] Furthermore, according to a fourth aspect of the present disclosure, the first circulation pipe may connect the gas storage tank to the exhaust pipe upstream of the first and second adsorption devices, and the controller may control the gas amount adjustment unit to circulate the gas that has flowed out of the gas storage tank upstream of the first and second adsorption devices via the first circulation pipe.

[0020] According to the fourth aspect, instead of releasing the CO2-containing gas into the atmosphere, the CO2-containing gas is repeatedly circulated within the CO2 capture system, thereby ensuring the greatest possible amount of CO2 capture compared to a configuration in which CO2 is released into the atmosphere.

[0021] Furthermore, according to a fifth aspect of the present disclosure, when desorbing CO2 from one of the first and second adsorption devices, the controller may desorb CO2 from the one adsorption device for a predetermined desorption period, release CO2-containing gas through the first flow pipe for a period equal to the desorption period, and control the gas amount adjustment unit so that the flow rate of the CO2-containing gas during the release is constant.

[0022] According to the fifth aspect, by synchronizing the CO2 desorption period and the CO2-containing gas release period, a sudden increase in exhaust pressure can be suppressed. This, combined with the suppression of a sudden change in exhaust pressure by keeping the flow rate of the CO2-containing gas constant, makes it possible to suppress a sudden increase in exhaust pressure as much as possible. As a result, the impact on the operation of the vehicle engine (especially work loss) can be suppressed as much as possible.

[0023] Furthermore, according to a sixth aspect of the present disclosure, when CO2 is desorbed from one of the first and second adsorption devices, the controller may control the gas amount adjustment unit so that the pressure of the exhaust gas in the exhaust pipe is equal to or lower than a predetermined pressure during the period of CO2 desorption from the one adsorption device, and the controller may determine the predetermined pressure based on the operating state of the vehicle engine.

[0024] Generally, the lower the rotation speed of the vehicle engine, the greater the room for increasing the exhaust pressure, and the lower the load on the vehicle engine, the greater the room for increasing the exhaust pressure. By controlling the amount or flow rate of CO2 to be desorbed according to the room for increasing the exhaust pressure, the exhaust pressure can be kept within a range appropriate for the operating state of the vehicle engine. [Effects of the Invention]

[0025] As described above, according to the present disclosure, it is possible to improve the CO2 storage efficiency. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram illustrating the overall configuration of a CO2 recovery system for an in-vehicle engine. [Figure 2] FIG. 2 is a system diagram illustrating the configuration of the collection system. [Figure 3] FIG. 3 is a diagram illustrating the configuration of a gas storage tank. [Figure 4] FIG. 4 is a block diagram illustrating the configuration of the controller. [Figure 5A] FIG. 5A is a diagram illustrating the functions performed by the flow path switching device. [Figure 5B] FIG. 5B is a diagram illustrating the functions performed by the flow path switching device. [Figure 6] FIG. 6 is a flowchart showing a specific example of adsorption control. [Figure 7] FIG. 7 is a flowchart showing a specific example of desorption control. [Figure 8] FIG. 8 is a flowchart showing a specific example of release control. [Figure 9] FIG. 9 is a view corresponding to FIG. 2 showing a second embodiment of the recovery system. [Figure 10] FIG. 10 is a flowchart showing another example of release control. [Figure 11] FIG. 11 is a diagram illustrating the pressure and temperature dependence of the CO2 adsorption amount in the CO2 adsorbent. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following description is for illustrative purposes only.

[0028] <1. Overall structure> 1 is a schematic diagram illustrating the overall configuration of a CO2 capture system S for an on-vehicle engine 1. Hereinafter, the "CO2 capture system S" may also be simply referred to as the "capture system S." This capture system S is connected between a cylinder 11 of the on-vehicle engine 1 and the downstream end of the exhaust pipe 2 (tail pipe 20).

[0029] The vehicle engine 1 is an internal combustion engine mounted on an automobile. The vehicle engine 1 has a cylinder 11 that forms a combustion chamber 12. The cylinder 11 is connected to an intake pipe 13 that supplies air from the outside to the combustion chamber 12, and an exhaust pipe 2 that discharges exhaust gas from the combustion chamber 12.

[0030] A tail pipe 20 is disposed at the downstream end of the exhaust pipe 2. The recovery system S according to this embodiment is disposed in the exhaust pipe 2 midway from the cylinder 11 to the tail pipe 20.

[0031] <2. Collection system> FIG. 2 is a system diagram illustrating the configuration of the recovery system S. In FIG. 2, the passage through which the exhaust gas flows, i.e., the exhaust pipe 2, is indicated by a thick solid line. In the same figure, a passage dedicated to the gas (gas that may contain CO2, hereinafter referred to as "CO2-containing gas") desorbed from the first and second adsorption devices 27A, 27B is indicated by a thin solid line. The exhaust pipe 2 also serves as a passage for the CO2-containing gas. In addition, in FIG. 2, the passage through which the heat exchange medium for cooling the exhaust gas flows is indicated by a dotted line. As shown in FIG. 2, the exhaust pipe 2 connects the cylinder 11 and the tailpipe 20.

[0032] A branching section 2a and a merging section 2b are arranged midway along the exhaust pipe 2. At the branching section 2a, the single exhaust pipe 2 branches into two exhaust pipes 2, each consisting of a first branching pipe 21 and a second branching pipe 22. At the merging section 2b, the first branching pipe 21 and the second branching pipe 22 merge again into a single pipe. A tail pipe 20 is connected to the combined exhaust pipe 2.

[0033] Hereinafter, "upstream" refers to "upstream" based on the flow direction of the exhaust gas or CO2-containing gas in the exhaust pipe 2. Similarly, "downstream" refers to "downstream" based on the flow direction of the exhaust gas or CO2-containing gas in the exhaust pipe 2. For example, the branching section 2a described above is disposed upstream of the junction section 2b, as shown in FIG. 2.

[0034] In the exhaust pipe 2, in a section from the cylinder 11 to the branching portion 2a, an exhaust catalyst 23, a first heat exchanger 24, and a first steam-water separator 25 are arranged in this order from the upstream side.

[0035] The exhaust catalyst 23 purifies the exhaust gas. The exhaust catalyst 23 purifies harmful components contained in the exhaust gas and emits harmless gas. The harmful components include NOx, CO, and HC. The harmless gas is a gas composed of nitrogen (N2), CO2, H2O, etc. The exhaust catalyst 23 is, for example, a three-way catalyst.

[0036] The first heat exchanger 24 is disposed downstream of the exhaust catalyst 23. The first heat exchanger 24 exchanges heat between the exhaust gas and a heat exchange medium so as to receive heat from the exhaust gas after passing through the exhaust catalyst 23. The heat exchange medium is, for example, a cooling liquid. The heat exchange medium is, for example, water. The first heat exchanger 24 is configured to pass the exhaust gas and to receive heat from the exhaust gas that has passed through it. The heat exchange medium circulates through a flow path system (heat exchange system 4) that is independent of the exhaust pipe 2.

[0037] The heat exchange system 4 is a system for circulating a heat exchange medium. The heat exchange medium circulating through the heat exchange system 4 receives heat in the first heat exchanger 24, passes through a second heat exchanger 38 (described later), and receives further heat in the second heat exchanger 38. The heat exchange medium that received heat in the second heat exchanger 38 is cooled by a third heat exchanger 41, and then passes through the first heat exchanger 24 again.

[0038] In this way, the heat exchange medium circulates through the heat exchange system 4 in the order of the first heat exchanger 24, the second heat exchanger 38, and the third heat exchanger 41. The third heat exchanger 41 is an electrically driven cooling device that is configured to cool the heat exchange medium passing through the third heat exchanger 41 and then send the cooled heat exchange medium to the first heat exchanger 24. The third heat exchanger 41 may be configured as a "chiller" that uses electric power to drive a pump and cools the heat exchange medium (cooled medium) with a circulating liquid circulated by the drive of the pump.

[0039] The first water-steam separator 25 is disposed downstream of the first heat exchanger 24. The first water-steam separator 25 separates condensed water generated in the exhaust gas from the exhaust gas. That is, the temperature of the exhaust gas that has passed through the first heat exchanger 24 drops by the amount of heat removed by the first heat exchanger 24. Due to this temperature drop, the water contained in the exhaust gas liquefies and becomes condensed water. The first water-steam separator 25 is configured to allow the exhaust gas to pass through and to collect condensed water from the exhaust gas that has passed through it.

[0040] In addition, in the exhaust pipe 2, in the section from the branching section 2a through the first branching pipe 21 to the confluence section 2b, there are arranged, in order from the upstream side, a first upstream control valve 26A, a first adsorption device 27A, and a first downstream control valve 28A.

[0041] The first upstream control valve 26A opens and closes the first branch pipe 21 upstream of the first adsorption device 27A. The first upstream control valve 26A is electrically connected to a controller 100 (described later), and opens and closes in response to a control signal received from the controller 100.

[0042] The first adsorption device 27A is disposed downstream of the exhaust catalyst 23, the first heat exchanger 24, the first steam-water separator 25, the branching section 2a, and the first upstream control valve 26A. The first adsorption device 27A is configured to include a CO2 adsorbent 271. The CO2 adsorbent 271 adsorbs CO2 in the exhaust gas at high pressure and / or low temperature, and desorbs the adsorbed CO2 at low pressure and / or high temperature.

[0043] Specifically, the CO2 adsorbent 271 according to this embodiment adsorbs more CO2 as the pressure decreases under the same temperature condition (equal temperature condition), and adsorbs more CO2 as the pressure approaches atmospheric pressure under the same pressure condition (equal pressure condition), as shown in Fig. 11. At a given temperature, the CO2 adsorbent 271 maximizes the amount of CO2 adsorbed near atmospheric pressure.

[0044] More specifically, the CO2 adsorbent 271 adsorbs CO2 in the exhaust gas when exhaust pressure (exhaust pressure) equal to or higher than atmospheric pressure is applied, that is, when the CO2 adsorption amount is at its maximum. Furthermore, the CO2 adsorbent 271 desorbs the adsorbed CO2 when negative pressure (lower than atmospheric pressure) is applied (specifically, when the vacuum pump 36, described later, is operating). The CO2 adsorbent 271 is, for example, an adsorbent made of zeolite.

[0045] These properties of the first adsorption device 27A are also common to the CO2 adsorbent 271 of the second adsorption device 27B. In this embodiment, these properties of the first adsorption device 27A are also common to the CO2 adsorbent 272 of the gas storage tank 51, but this commonality is not essential.

[0046] The CO2 adsorbent 271 of this embodiment is configured to desorb CO2 mainly by the pressure swing method using the vacuum pump 36. The first heat exchanger 24 of this embodiment is configured to separate condensed water from the exhaust gas and to promote adsorption of CO2 by the CO2 adsorbent 271. That is, in this embodiment, while the pressure swing method is mainly used, the temperature dependency of the amount of CO2 adsorption in the CO2 adsorbent 271 is also partially used in combination.

[0047] The first downstream control valve 28A opens and closes the first branch pipe 21 downstream of the first adsorption device 27A. The first downstream control valve 28A is electrically connected to a controller 100 (described later), and opens and closes in response to a control signal received from the controller 100.

[0048] In addition, in the exhaust pipe 2, in the section from the branching section 2a through the second branching pipe 22 to the confluence section 2b, there are arranged, in order from the upstream side, a second upstream control valve 26B, a second adsorption device 27B, and a second downstream control valve 28B.

[0049] The second upstream control valve 26B opens and closes the second branch pipe 22 upstream of the second adsorption device 27B. The second upstream control valve 26B is electrically connected to a controller 100 (described later) and opens and closes in response to a control signal from the controller 100.

[0050] The second adsorption device 27B is disposed downstream of the exhaust catalyst 23, the first heat exchanger 24, the first steam-water separator 25, the branching section 2a, and the second upstream control valve 26B. The second adsorption device 27B is configured to include a CO2 adsorbent 271. The CO2 adsorbent 271 adsorbs CO2 in the exhaust gas at high pressure and / or low temperature, and desorbs the adsorbed CO2 at low pressure and / or high temperature.

[0051] Specifically, the CO2 adsorbent 271 according to this embodiment adsorbs more CO2 as the pressure decreases under the same temperature condition (equal temperature condition), and adsorbs more CO2 as the pressure approaches atmospheric pressure under the same pressure condition (equal pressure condition), as shown in Fig. 11. At a given temperature, the CO2 adsorbent 271 maximizes the amount of CO2 adsorbed near atmospheric pressure.

[0052] More specifically, the CO2 adsorbent 271 adsorbs CO2 in the exhaust gas when exhaust pressure (exhaust pressure) equal to or higher than atmospheric pressure is applied, that is, when the CO2 adsorption amount is at its maximum. Furthermore, the CO2 adsorbent 271 desorbs the adsorbed CO2 when negative pressure (lower than atmospheric pressure) is applied (specifically, when the vacuum pump 36, described later, is operating). The CO2 adsorbent 271 is, for example, an adsorbent made of zeolite.

[0053] As shown in FIG. 2, the second adsorption device 27B can be considered to be connected in parallel with the first adsorption device 27A in the flow direction of the exhaust gas.

[0054] The second downstream control valve 28B opens and closes the second branch pipe 22 downstream of the second adsorption device 27B. The second downstream control valve 28B is electrically connected to a controller 100 (described later), and opens and closes in response to a control signal received from the controller 100.

[0055] A desorbed gas circulation system 3 that circulates the CO2-containing gas desorbed from the first and second adsorption devices 27A and 27B is connected to the first and second branch pipes 21 and 22. The desorbed gas circulation system 3 according to this embodiment is configured as one element of the recovery system S.

[0056] Specifically, a first desorption branch 2c is provided in a portion of the first branch pipe 21 between the first upstream control valve 26A and the first adsorption device 27A. A third branch pipe 31, through which the CO2-containing gas desorbed from the first adsorption device 27A flows, is connected to the first desorption branch 2c.

[0057] Similarly, a second desorption branch 2d is provided in a portion of the second branch pipe 22 between the second upstream control valve 26B and the second adsorption device 27B. A fourth branch pipe 32, through which the CO2-containing gas desorbed from the second adsorption device 27B flows, is connected to the second desorption branch 2d.

[0058] A first desorption control valve 33 is disposed in the third branch pipe 31 to open and close the third branch pipe 31. A second desorption control valve 34 is disposed in the fourth branch pipe 32 to open and close the fourth branch pipe 32. The first and second desorption control valves 33 and 34 are each electrically connected to the controller 100, and open and close in response to a control signal from the controller 100.

[0059] The third branch pipe 31 and the fourth branch pipe 32 join at a desorbed gas junction 2e to form an integrated desorbed gas pipe 35. In the desorbed gas pipe 35, a vacuum pump 36, a compressor 37, a second heat exchanger 38, a second steam-water separator 39, and a gas storage tank 51 are arranged in this order from the upstream side in the flow direction of the desorbed gas (CO2-containing gas).

[0060] The vacuum pump 36 generates an air pressure (negative pressure) that is lower than atmospheric pressure. The vacuum pump 36 is electrically connected to the controller 100 and operates in response to a control signal from the controller 100. The negative pressure generated by the vacuum pump 36 can promote desorption of CO2 from the first and second adsorption devices 27A, 27B. Heaters that heat the first and second adsorption devices 27A, 27B, respectively, may be used instead of the vacuum pump 36.

[0061] The compressor 37 compresses the CO2-containing gas that is sucked into the vacuum pump 36 and passes through the vacuum pump 36. The compressor 37 is electrically connected to the controller 100, and operates upon receiving a control signal from the controller 100.

[0062] The second heat exchanger 38 is disposed downstream of the compressor 37. More generally, the second heat exchanger 38 according to this embodiment is disposed midway from the CO2 adsorbents 271 of the first and second adsorption devices 27A and 27B to the gas storage tank 51. The second heat exchanger 38 exchanges heat between the exhaust gas and a heat exchange medium so as to receive heat from the CO2-containing gas after passing through the compressor 37.

[0063] The second steam-water separator 39 is disposed downstream of the second heat exchanger 38 and upstream of the gas storage tank 51, and separates condensed water generated in the CO2-containing gas from the CO2-containing gas. That is, the temperature of the CO2-containing gas that has passed through the second heat exchanger 38 drops by the amount of heat removed by the second heat exchanger 38. Due to this temperature drop, the water contained in the CO2-containing gas liquefies to become condensed water. The second steam-water separator 39 is configured to allow the CO2-containing gas to pass through and to collect condensed water from the CO2-containing gas that has passed through it.

[0064] 3 is a diagram illustrating the configuration of the gas storage tank 51. The gas storage tank 51 is disposed downstream of the second steam-water separator 39. More generally, the gas storage tank 51 according to this embodiment is disposed downstream of the first and second adsorption devices 27A and 27B and the CO2 adsorbents 271 provided therein. The gas storage tank 51 receives the CO2-containing gas from one of the first and second adsorption devices 27A and 27B.

[0065] 3, the gas storage tank 51 contains a CO2 adsorbent 272. The CO2 adsorbent 272 contained in the gas storage tank 51 may be the same as the zeolite CO2 adsorbent 271 contained in the first and second adsorption devices, or may be a different material.

[0066] The gas storage tank 51 has an inlet 51a and an outlet 51b. The outlet 51b is open so that the gas that has flowed into the gas storage tank 51 can flow out of the gas storage tank 51.

[0067] A first flow pipe 52 is connected to the discharge port 51b. The first flow pipe 52 forms a pipeline through which gas flows out of the gas storage tank 51. In this embodiment, the first flow pipe 52 connects the gas storage tank 51 to the exhaust pipe 2 upstream of the first and second adsorption devices 27A and 27B.

[0068] Specifically, the upstream end of the first circulation pipe 52 is connected to the discharge port 51b of the gas storage tank 51. The downstream end of the first circulation pipe 52 is connected to the exhaust pipe 2 between the first steam-water separator 25 and the branching portion 2a. As will be described in a second embodiment later, the downstream end of the first circulation pipe 52 may be open to the atmosphere.

[0069] In the first flow pipe 52, a gas amount adjustment unit 53 and a check valve 54 are arranged in this order from the upstream side. The gas amount adjustment unit 53 adjusts the amount (particularly the flow rate) of the CO2-containing gas flowing out through the first flow pipe 52. In this embodiment, the gas amount adjustment unit 53 is configured by a control valve whose opening can be adjusted between a fully open state and a fully closed state. The gas amount adjustment unit 53 is electrically connected to the controller 100, and changes its opening upon receiving a control signal from the controller 100.

[0070] <3. Controller> 4 is a block diagram illustrating the configuration of the controller 100. The controller 100 includes hardware such as a processor 100a, a memory 100b, and an input / output bus 100c, as well as software such as a database and a control program. The controller 100 is configured by a so-called ECU (Engine Control Unit).

[0071] Various sensors are connected to the controller 100. Specifically, an accelerator pedal sensor Sw1, an engine rotation speed sensor Sw2, an exhaust temperature sensor Sw3, an exhaust pressure sensor Sw4, an adsorption layer temperature sensor Sw5, and a tank pressure sensor Sw6 are connected to the controller 100 so as to be able to receive electrical signals from them. The controller 100 receives the electrical signals generated by these sensors.

[0072] The accelerator pedal sensor Sw1 detects the depression of the vehicle's accelerator pedal and generates an electrical signal indicating the detected depression. The engine speed sensor Sw2 detects the rotation speed of the vehicle engine 1 and generates an electrical signal indicating the detected rotation speed. The exhaust temperature sensor Sw3 detects the temperature of the exhaust gas flowing through the exhaust pipe 2 and generates an electrical signal indicating the detected temperature. The exhaust pressure sensor Sw4 detects the pressure of the exhaust gas flowing through the exhaust pipe 2 and generates an electrical signal indicating the detected pressure. The adsorption bed temperature sensor Sw5 detects the temperature of the CO2 adsorbent 271 in each of the first adsorption device 27A and the second adsorption device 27B and generates an electrical signal indicating each detected temperature. The tank pressure sensor Sw6 detects the pressure of the air in the gas storage tank 51 and generates an electrical signal indicating the detected pressure.

[0073] Various actuators are connected to the controller 100. Specifically, the first upstream control valve 26A, the first downstream control valve 28A, the second upstream control valve 26B, the second downstream control valve 28B, the first and second desorption control valves 33, 34, the vacuum pump 36, the compressor 37, and the gas amount adjuster 53 are connected to the controller 100 so as to be able to transmit electrical signals.

[0074] Hereinafter, among these actuators, the first upstream control valve 26A, the first downstream control valve 28A, the second upstream control valve 26B, the second downstream control valve 28B, and the first and second desorption control valves 33, 34 will be collectively referred to as the flow path switching device 5. The function performed by the flow path switching device 5 will be described later.

[0075] The controller 100 generates control signals based on the electrical signals input from the sensors described above, and inputs the signals to various actuators electrically connected to the controller 100 .

[0076] For example, the controller 100 can calculate a target load for the vehicle engine 1 based on the opening degree detected by the accelerator pedal sensor Sw1. This target load can be used for operating the vehicle engine, such as adjusting the fuel injection amount, or for controlling the gas amount adjusting unit 53, which will be described later.

[0077] 5A and 5B are diagrams for explaining the functions performed by the flow path switching device 5. In these figures, the heat exchange system 4 is shown with most of it omitted for clarity of the drawings.

[0078] Among the circuit symbols showing control valves in Figures 5A and 5B, the open circuit symbols indicate that the valve is in an open state. Similarly, among the circuit symbols showing control valves in Figures 5A and 5B, the filled circuit symbols indicate that the valve is in a closed state. The meanings of solid lines, dashed lines, etc. in Figures 5A and 5B are as shown in the legends of each figure.

[0079] The flow path switching device 5 according to this embodiment can alternately switch the first and second adsorption devices 27A, 27B between a state in which they are connected between the exhaust catalyst 23 and the tail pipe 20 and a state in which they are disconnected from the exhaust catalyst 23 and connected to the gas storage tank 51. This switching can be performed based on an electrical signal input from the controller 100 to the flow path switching device 5.

[0080] The former state (adsorption state) contributes to the adsorption of CO2 from the exhaust gas and the discharge of the exhaust gas with adsorbed CO2. The latter state (desorption state) contributes to the desorption of CO2 adsorbed in the adsorption device and the supply of CO2-containing gas to the gas storage tank 51. Hereinafter, for each of the first and second adsorption devices 27A and 27B, the process for setting the flow path structure to the adsorption state will be referred to as "adsorption control." Similarly, for each of the first and second adsorption devices 27A and 27B, the process for operating the vacuum pump 36 after setting the flow path structure to the desorption state will be referred to as "desorption control."

[0081] 5A, the first upstream control valve 26A and the first downstream control valve 28A are opened, and the second upstream control valve 26B and the second downstream control valve 28B are closed. At the same time, the first desorption control valve 33 is closed, and the second desorption control valve 34 is opened. In this case, the first adsorption device 27A is in an adsorption state, and the second adsorption device 27B is in a desorption state.

[0082] 5B, the first upstream control valve 26A and the first downstream control valve 28A are closed, and the second upstream control valve 26B and the second downstream control valve 28B are opened. At the same time, the first desorption control valve 33 is opened, and the second desorption control valve 34 is closed. In this case, the first adsorption device 27A is in a desorption state, and the second adsorption device 27B is in an adsorption state.

[0083] The controller 100 alternately switches the first and second adsorption devices 27A, 27B between an "adsorption state" and a "desorption state." This allows the two adsorption devices to perform well-balanced adsorption and desorption of CO2. When one of the first and second adsorption devices 27A, 27B is in the "adsorption state," the other is in the "desorption state." When the first adsorption device 27A transitions in the order of the "adsorption state," "desorption state," and "adsorption state," the second adsorption device 27B transitions in the order of the "desorption state," "adsorption state," and "desorption state."

[0084] In addition to the adsorption control and desorption control described above, the controller 100 is configured to execute a process (release control) for appropriately releasing the gas stored in the gas storage tank 51 so as to prevent excessive pressure from building up in the tank 51. Specific examples of processes including the release control will be described below with reference to flowcharts.

[0085] <4. Specific examples of processing by the controller> (4-1. Adsorption control) 6 is a flowchart showing a specific example of suction control. Here, suction control for the first suction device 27A will be described, but suction control for the second suction device 27B is also performed in the same manner.

[0086] First, in step S101 of Fig. 6, the controller 100 reads the detection signals from the sensors exemplified in Fig. 4. The subsequent processing is performed when the first suction device 27A is in the suction state.

[0087] In the following step S102, the controller 100 estimates the CO2 adsorption amount at that time for the CO2 adsorbent 271 in the first adsorption device 27A based on the target load of the engine 1 calculated based on the accelerator pedal sensor Sw1, the engine speed, the detected temperature of the exhaust, and the detected temperature of the CO2 adsorbent 271.

[0088] In the following step S103, the controller 100 determines whether the estimated value of the CO2 adsorption amount (estimated adsorption amount) obtained in step S102 has reached or exceeded a value (predetermined value) near the adsorption limit of the CO2 adsorbent 271 in the first adsorption device 27A. If this determination is NO, the controller 100 skips the following step S104 and returns. In this case, the first adsorption device 27A is maintained in an adsorption state, and the second adsorption device 27B is maintained in a desorption state. Note that the predetermined value here is the maximum value that can be adsorbed at atmospheric pressure or exhaust pressure during idling. It is advantageous for the CO2 adsorbent 271 in the present disclosure to have a characteristic (see FIG. 11) that maximizes its CO2 adsorption amount at atmospheric pressure or during idling.

[0089] On the other hand, if the determination in step S103 is YES, the controller 100 advances the control process to step S104. In step S103, the controller 100 controls the flow path switching device 5 to change the first adsorption device 27A from the adsorption state to the desorption state and change the second adsorption device 27B from the desorption state to the adsorption state. When the first adsorption device 27A is changed to the desorption state, the controller 100 executes desorption control, which will be described later, on the first adsorption device 27A instead of adsorption control.

[0090] (4-2. Desorption control) 7 is a flowchart showing a specific example of desorption control. Here, desorption control for the first adsorption device 27A will be described, but desorption control for the second adsorption device 27B is also performed in the same manner.

[0091] First, in step S201 of Fig. 6, the controller 100 reads the detection signals from the sensors exemplified in Fig. 4. The subsequent processing is performed when the first suction and absorption device 27A is in the detaching state.

[0092] In the following step S202, the controller 100 predicts the period (desorption period) required for CO2 to be desorbed from the CO2 adsorbent 271 in the first adsorption device 27A based on the target load of the engine 1 calculated based on the accelerator pedal sensor Sw1, the engine speed, the detected temperature of the exhaust, and the detected temperature of the CO2 adsorbent 271.

[0093] In the next step S203, the controller 100 determines the flow rate (introduction flow rate) of the CO2-containing gas flowing out from the first adsorption device 27A per unit time according to the desorption period predicted in step S202. The longer the desorption period, the smaller the flow rate of the CO2-containing gas. The estimated adsorption amount calculated in the adsorption control may be used to determine the desorption period or the introduction flow rate.

[0094] In the following step S204, the controller 100 controls the vacuum pump 36 based on the introduction flow rate determined in step S203 and the detected pressure in the gas storage tank 51.

[0095] In the following step S205, the controller 100 estimates the amount of CO2 desorption at that time from the CO2 adsorbent 271 of the first adsorption device 27A based on the introduction flow rate determined in step S203 and the elapsed time since the first adsorption device 27A was placed in a desorption state.

[0096] In the following step S206, the controller 100 determines whether the estimated value of the CO2 desorption amount (estimated desorption amount) obtained in step S205 has reached or exceeded a value (predetermined value) near the desorption limit of the CO2 adsorbent 271 in the first adsorption device 27A. If the determination is NO, the controller 100 returns to step S204. In this case, the first adsorption device 27A is maintained in a desorption state, and the second adsorption device 27B is maintained in an adsorption state.

[0097] On the other hand, if the determination in step S206 is YES, the controller 100 advances the control process to step S207. In step S207, the controller 100 controls the flow path switching device 5 to change the first adsorption device 27A from the desorption state to the adsorption state, and change the second adsorption device 27B from the adsorption state to the desorption state. When the first adsorption device 27A is changed to the adsorption state, the controller 100 executes the above-described adsorption control instead of the desorption control for the first adsorption device 27A.

[0098] As described above, the first and second adsorption devices 27A, 27B are alternately switched between an "adsorption state" and a "desorption state." That is, when one of the first and second adsorption devices 27A, 27B is in the "adsorption state," the other of the first and second adsorption devices 27A, 27B is in the "desorption state." The adsorption control illustrated in FIG. 6 is executed for one of the devices in the adsorption state, and the desorption control illustrated in FIG. 7 is executed for the other device in the desorption state.

[0099] In this case, adsorption control of one of the first and second adsorption devices 27A, 27B in the "adsorption state" and desorption control of the other in the "desorption state" are simultaneously executed. If the determination in step S103 in the adsorption control or the determination in step S206 in the desorption control is YES first, the controller 100 forcibly switches between the "adsorption state" and the "desorption state" without waiting for the other determination to be YES.

[0100] Specifically, when the determination in step S103 in the adsorption control or the determination in step S206 in the desorption control becomes YES first, the controller 100 executes the process of step S104 without waiting for the determination in step S206 to become YES. One of the first and second adsorption devices 27A, 27B that has been executing the adsorption control transitions from the "adsorption state" to the "desorption state" and then starts the desorption control of Fig. 7. The other of the first and second adsorption devices 27A, 27B that has been executing the desorption control forcibly stops the desorption control, transitions forcibly from the "desorption state" to the "adsorption state", and then starts the adsorption control of Fig. 6.

[0101] Similarly, if the determination in step S103 in the adsorption control or the determination in step S206 in the desorption control becomes YES first, the controller 100 executes the process of step S207 without waiting for the determination in the former to become YES. One of the first and second adsorption devices 27A, 27B that was executing the desorption control transitions from the "desorption state" to the "adsorption state" and then starts the adsorption control of Fig. 6. The other of the first and second adsorption devices 27A, 27B that was executing the adsorption control forcibly stops the adsorption control, transitions from the "adsorption state" to the "desorption state", and then starts the desorption control of Fig. 7.

[0102] (4-3. Release control) Fig. 8 is a flowchart showing a specific example of release control. The release control is performed in parallel with the adsorption control and desorption control described above. First, in step S301 of Fig. 8, the controller 100 predicts the desorption period in the same manner as in step S202 of the desorption control, and sets the release period of the CO2-containing gas from the gas storage tank 51 so that it is the same period as the desorption period.

[0103] In the following step S302, the controller 100 determines the flow rate (release flow rate) of the CO2-containing gas released from the gas storage tank 51 per unit time based on the desorption period (release period) predicted in step S301. The longer the release period, the smaller the release flow rate.

[0104] When desorbing CO2 from one of the first and second adsorption devices 27A, 27B, the controller 100 calculates the sum of the volume of the exhaust pipe 2 that is common to both the adsorption state and the desorption state (see the dashed line in FIGS. 5A and 5B) and the volume of one of the first and second adsorption devices 27A, 27B that is in the desorption state. A predetermined amount of CO2 corresponding to this sum is desorbed by desorption control. The aforementioned release flow rate is determined to be a flow rate corresponding to this predetermined amount.

[0105] In the following step S303, the controller 100 controls the gas amount adjustment unit 53 so as to maintain a constant flow rate based on the release flow rate determined in step S302, the detected pressure inside the gas storage tank 51, and the detected pressure of the exhaust gas. This starts the release of the CO2-containing gas from the gas storage tank 51. The controller 100 controls the gas amount adjustment unit 53, causing the CO2-containing gas to flow out of the gas storage tank 51. The CO2-containing gas that has flowed out of the gas storage tank 51 circulates via the first flow pipe 52 to the upstream of the first and second adsorption devices 27A and 27B.

[0106] In the following step S304, the controller 100 determines whether the elapsed time since the release of the CO2-containing gas from the gas storage tank 51 was started in step S303 has reached the release period set in step S301. If the determination is NO, the controller 100 returns to the determination in step S304. If the determination is YES, the controller 100 ends the determination in step S304 and ends the flow illustrated in FIG. 7.

[0107] In this way, the controller 100 controls the gas amount adjustment unit 53 to allow a predetermined amount of the CO2-containing gas that has flowed into the gas storage tank 51 from the adsorption device 27A, 27B, which is in a desorption state, of the first and second adsorption devices, to flow out of the gas storage tank 51.

[0108] In particular, in the first specific example, when desorbing CO2 from the adsorption device 27 in a desorption state, the controller 100 causes the adsorption device 27 to desorb CO2 for a predetermined release period (desorption period). The controller 100 causes the CO2-containing gas to be released through the first flow pipe 52 for the same period as the release period, and controls the gas amount adjustment unit 53 so that the flow rate of the CO2-containing gas (release flow rate) during the release becomes a constant predetermined amount.

[0109] <5. Significance of this embodiment> As described above, according to the embodiment, as illustrated in Fig. 2, the CO2-containing gas is appropriately released from the gas storage tank 51. As a result, the CO2 in the CO2-containing gas is adsorbed by the CO2 adsorbent 272 built into the gas storage tank 51, while the other components in the CO2-containing gas are released from the gas storage tank 51. Since the CO2 is adsorbed by the CO2 adsorbent 272, the pressure inside the gas storage tank 51 can be kept low. On the other hand, by releasing the other components, the pressure inside the gas storage tank 51 can be suppressed as much as possible.

[0110] Thus, by combining the fact that CO2 is adsorbed by the CO2 adsorbent 272 and the fact that the pressure inside the gas storage tank 51 is suppressed as much as possible, it is possible to improve the storage efficiency of CO2.

[0111] 2 and 8, the CO2-containing gas is actively discharged to the outside of the gas storage tank 51 via the gas amount regulator 53, thereby suppressing the pressure inside the gas storage tank 51 as much as possible, thereby improving the CO2 storage efficiency.

[0112] 5A and 5B, components such as nitrogen originating from the exhaust gas that passed through during the adsorption state are thought to remain in the exhaust pipe 2, which is common to both the adsorption state and the desorption state, and in the adsorption devices 27A and 27B that communicate with the exhaust pipe 2. Therefore, by controlling the gas amount adjustment unit 53 so that an amount of gas commensurate with the volume of that portion is discharged, it is possible to accurately remove such remaining components.

[0113] 2, instead of releasing the CO2-containing gas into the atmosphere, the gas is repeatedly circulated within the CO2 capture system S. This makes it possible to capture as much CO2 as possible, compared to a configuration in which CO2 is released into the atmosphere.

[0114] Furthermore, as explained with reference to FIG. 8 etc., by synchronizing the CO2 desorption period and the CO2-containing gas release period (setting them to coincide), a sudden increase in exhaust pressure can be suppressed. This, combined with the suppression of a sudden change in exhaust pressure by keeping the flow rate of the CO2-containing gas constant, makes it possible to suppress a sudden increase in exhaust pressure as much as possible. As a result, the impact on the operation of the vehicle engine 1 (particularly, work loss) can be suppressed as much as possible.

[0115] <Other embodiments> In the above embodiment, it has been disclosed that the gas amount adjuster 53 is controlled so that the amount of gas discharged corresponds to the volume of the exhaust pipe 2, but the present disclosure is not limited to such a configuration. Control may also be performed according to the operating state of the vehicle engine 1.

[0116] Specifically, in another example of release control, when CO2 is desorbed from one of the first and second adsorption devices 27A, 27B, the controller 100 controls the gas amount adjustment unit 53 so that the pressure of the exhaust gas in the exhaust pipe 2 is equal to or lower than a predetermined pressure during the period when CO2 is desorbed from one of the adsorption devices. When executing such another example, the controller 100 determines the predetermined pressure based on the operating state of the vehicle engine 1.

[0117] Generally, the lower the rotation speed of the vehicle engine 1, the greater the room for increasing the exhaust pressure. By controlling the amount or flow rate of CO2 to be desorbed according to the room for increasing the exhaust pressure, the exhaust pressure can be kept within a range appropriate for the operating state of the vehicle engine 1.

[0118] More specifically, as illustrated in Fig. 101, the controller 100 reads the sensor detection value, similar to step S201 of Fig. 7, and then determines whether the current exhaust pressure is equal to or lower than a predetermined pressure (steps S401 and S402). If the determination is YES, the controller 100 sets a flow rate such that the CO2-containing gas reaches near the predetermined pressure during circulation (step S403). The controller 100 starts control of the vacuum pump 36 to achieve the flow rate (step S404). Then, on the condition that the elapsed time since the start of the release control reaches a predetermined adsorption period (step S405), the controller 100 ends control of the vacuum pump 36 (step S406), thereby terminating the release control.

[0119] In the above embodiment, the compressor 37 is disposed downstream of the vacuum pump 36, but the compressor 37 is not essential. Also, instead of or in addition to the vacuum pump 36, heaters capable of individually heating the first and second adsorption devices 27A, 27B may be used.

[0120] In this case, in this embodiment, the adsorption and desorption of CO2 is dominated by the pressure swing method using exhaust pressure and the vacuum pump 36, but if both the vacuum pump 36 and a heater are used, the pressure swing method using the exhaust pressure and the vacuum pump 36 and the temperature swing method using the heat exchanger and heater are used together during both adsorption and desorption. Furthermore, if a heater is used instead of the vacuum pump 36 without using the vacuum pump 36, the temperature swing method using the heat exchanger and heater becomes dominant. Furthermore, if the compressor 37 is eliminated, the gas amount adjustment unit 53 may be configured using a pump instead of a control valve.

[0121] Furthermore, a configuration for recirculating CO2-containing gas is not essential to the present disclosure. For example, as in the CO2 capture system S' shown in Figure 9, the first circulation pipe 52 may be open to the atmosphere. In the configuration example of Figure 9, the compressor 37 may be omitted as described above. In that case, the gas amount adjustment unit 53, which is composed of a control valve or the like, may be omitted.

[0122] 6 and 7. For example, a CO2 concentration sensor may be disposed in the tail pipe 20, and when the detected CO2 concentration is equal to or greater than a predetermined value, the connection structure of the first or second adsorption device 27A, 27B may be switched to start desorption of CO2. Alternatively, a pressure sensor may be disposed in the gas piping upstream of the vacuum pump 36, and when the detected pressure is less than a predetermined value, the connection structure of the first or second adsorption device 27A, 27B may be switched to start adsorption of CO2. [Explanation of symbols]

[0123] S CO2 capture system 1. Vehicle engine 11 cylinders 2 exhaust pipes 20 Tail pipe (downstream end) 23 Exhaust catalyst 24 1st heat exchanger 25 1st steam separator 27A 1st adsorption device 27B Second adsorption device 271 CO2 absorbent 5 Flow path switching device 26A First upstream control valve (flow path switching device) 26B First downstream control valve (flow path switching device) 28A First downstream control valve (flow path switching device) 28B Second downstream control valve (flow path switching device) 33 First desorption control valve (flow path switching device) 34 Second desorption control valve (flow path switching device) 36 Vacuum pump 38 Second heat exchanger 39 Second steam / water separator 51 Gas storage tank 51b Outlet 52 1st flow pipe 53 Gas volume adjustment unit 100 Controllers

Claims

1. The exhaust gas purifier is disposed between a cylinder of an on-vehicle engine and the downstream end of an exhaust pipe, and allows the exhaust gas discharged from the cylinder to flow through the exhaust gas purifier. ２ CO2 from vehicle engines ２ 1. A recovery system comprising: The exhaust catalyst is disposed downstream of the exhaust catalyst, and the CO in the exhaust gas is removed during at least one of high pressure and low temperature. ２ and adsorbs the adsorbed CO at least at one of low pressure and high temperature. ２ CO desorbed ２ a first adsorption device configured to include an adsorbent; the CO ２ a second adsorption device configured to include an adsorbent; a CO 2 adsorbed from one of the first and second adsorption devices, disposed downstream of the first and second adsorption devices; ２ containing CO ２ The CO ２ a gas storage tank having an adsorbent built therein; a flow path switching device that switches each of the first and second adsorption devices between an adsorption state in which the first and second adsorption devices are connected between the exhaust catalyst and the downstream end and a desorption state in which the first and second adsorption devices are disconnected from the exhaust catalyst and connected to the gas storage tank, The gas storage tank is configured to ２ The gas storage tank has a discharge port for discharging the contained gas to the outside. CO2 of an on-vehicle engine ２ 1. A recovery system comprising:

2. The CO2 of the vehicle engine according to claim 1. ２ In the collection system, CO 2 flowing out from the gas storage tank connected to the outlet ２ a first flow pipe through which the contained gas flows; The CO 2 is disposed in the first flow pipe and flows out through the first flow pipe. ２ a gas amount adjusting unit that adjusts the amount of contained gas; a controller for controlling the gas amount adjusting unit, The controller controls the gas amount adjusting unit to adjust the amount of CO 2 that has flowed into the gas storage tank from the adsorption device that is in the desorption state, of the first and second adsorption devices. ２ A predetermined amount of the contained gas is discharged to the outside of the gas storage tank. CO2 of an on-vehicle engine ２ Collection system.

3. The CO2 of the vehicle engine according to claim 2. ２ In the collection system, The controller is configured to detect CO 2 from one of the first and second adsorption devices. ２ Upon the departure of calculating a sum of a volume of the exhaust pipe that is common to both the adsorption state and the desorption state and a volume of one of the first and second adsorption devices that is in the desorption state; The gas amount adjusting unit is controlled so that the predetermined amount becomes the total value. CO2 of an on-vehicle engine ２ Collection system.

4. The CO2 of the vehicle engine according to claim 2. ２ In the collection system, the first flow pipe connects the gas storage tank to the exhaust pipe upstream of the first and second adsorption devices; The controller controls the gas amount adjusting unit to circulate the gas discharged to the outside of the gas storage tank to the upstream of the first and second adsorption devices via the first circulation pipe. CO2 of an on-vehicle engine ２ Collection system.

5. The CO2 of the vehicle engine according to claim 4. ２ In the collection system, The controller is configured to detect CO 2 from one of the first and second adsorption devices. ２ Upon the departure of CO 2 is desorbed from the one adsorption device over a predetermined desorption period. ２ Desorbing CO is introduced through the first flow pipe for the same period as the desorption period. ２ The contained gas is released, and at the time of the release, CO ２ The gas amount adjusting unit is controlled so that the flow rate of the contained gas is constant. CO2 of an on-vehicle engine ２ Collection system.

6. The CO2 of the vehicle engine according to claim 4. ２ In the collection system, The controller is configured to detect CO 2 from one of the first and second adsorption devices. ２ Upon the departure of CO from one of the adsorption units ２ During the desorption period, the gas amount adjusting unit is controlled so that the pressure of the exhaust gas in the exhaust pipe is equal to or lower than a predetermined pressure, The controller determines the predetermined pressure based on an operating state of the vehicle engine. CO2 of an on-vehicle engine ２ Collection system.

Images