Carbon dioxide recovery device

Abstract

The problem to be solved by the present invention is to provide a carbon dioxide recovery device capable of accurately raising and cooling the temperature in a desorption step and an adsorption step with a heat medium at an appropriate flow rate, and capable of saving energy. In order to solve the problem, this carbon dioxide recovery device (1) is provided with: a bypass line (31) capable of introducing a heat medium that has passed through a first module (11a) into a second module (11b) that is different from the first module (11a); an upstream-side four-way valve (30a) and a downstream-side four-way valve (30b), which are disposed in each of the modules (11), can switch the path of the heat medium supplied to the modules (11) from the hot water line (112), the cold water line (111), or the bypass line (31), and can adjust the flow rate of the heat medium passing through the modules (11); and a control device (90) that, by controlling the upstream four-way valve (30a) and the downstream four-way valve (30b), changes switching control for switching the path of the heat medium and flow rate control for adjusting the flow rate of the heat medium in accordance with the condition of the adsorber (12).

Description

Technical Field

[0001] The invention relates to a carbon dioxide recovery device. Background Art

[0002] Conventionally, technologies for recovering carbon dioxide from gases containing carbon dioxide, such as the atmosphere, are known. Patent Document 1, for example, describes such technologies. Patent Document 1 describes a method for separating gaseous carbon dioxide from a gas mixture through cyclic adsorption / desorption using an adsorbent that adsorbs gaseous carbon dioxide.

[0003] [Prior Art Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application No. 2017-528318 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] For example, in a CO2 recovery system that uses multiple modules with adsorbents and performs desorption and adsorption processes in parallel, the adsorbents in the first module are sometimes cooled by a cooling heat medium, while the adsorbents in the second module are heated by a heating heat medium. To improve energy efficiency, it is possible to recover exhaust heat from the first module and use this recovered heat to heat the adsorbents in the second module.

[0008] There is also a situation where the exhaust heat recovery from the first module alone is not sufficient to raise the temperature of the adsorbent of the second module to a desorbable temperature. It is also possible to consider switching the heat medium to be used according to the temperature increase stage, but the necessary and sufficient flow rate of the heat medium flowing into the module varies depending on the temperature potential of the heat medium to be used, the desorption process, and the various stages of the adsorption process. Therefore, if the heat medium is circulated at a fixed flow rate without considering the temperature potential of the heat medium supplied to the module and the condition of the adsorbent, there is a possibility that the adsorbent will be overheated or cooled. In addition, since the flow rate is directly related to the work done by the pump, the flow rate of the heat medium is preferably set to the minimum necessary limit. It is desirable to achieve energy saving in the carbon dioxide recovery device, but the existing technology still has problems in terms of suppressing the power consumption of the pump used to circulate the heat medium.

[0009] An object of the present invention is to provide a carbon dioxide recovery apparatus that can accurately perform temperature increase and cooling in a desorption process and an adsorption process using a heat medium at an appropriate flow rate, thereby achieving energy saving.

[0010] [Technical means to solve the problem]

[0011] (1) The present invention is a carbon dioxide recovery device (for example, the carbon dioxide recovery device 1 described later), comprising: a plurality of modules (for example, the module 11 described later), each having an adsorbent (for example, the adsorbent 12 described later) inside, and performing an adsorption process and a desorption process, wherein the adsorption process is to draw a gas containing carbon dioxide into the adsorbent so that the adsorbent adsorbs the carbon dioxide, and the desorption process is to desorb the carbon dioxide from the adsorbent by heating the periphery of the adsorbent under a reduced pressure state; a heating heat medium pipeline (for example, the warm water pipeline 112 described later), for supplying a relatively high-temperature heat medium (for example, the warm water described later) to each of the plurality of modules so as to heat the adsorbent performing the desorption process; a cooling heat medium pipeline (for example, the cold water pipeline 111 described later), for supplying a relatively low-temperature heat medium (for example, the cold water described later) so as to cool the adsorbent performing the adsorption process; a heat source (for example, the hot water pipeline 112 described later); The heat source 81 is configured to heat the heat medium flowing through the heating heat medium line and cool the heat medium flowing through the cooling heat medium line. A bypass line (e.g., the bypass line 31 described below) is configured to guide the heat medium that has passed through one of the plurality of modules, namely, a first module, to a second module different from the first module. A flow control device (e.g., the upstream four-way valve 30a and the downstream four-way valve 30b described below) is disposed in each of the modules and is configured to switch the path of the heat medium supplied to the module from the heating heat medium line, the cooling heat medium line, or the bypass line, and to adjust the flow rate of the heat medium passing through the module. A control device (e.g., the control device 90 described below) controls the flow control device to change the switching control for switching the path of the heat medium and the flow rate control for adjusting the flow rate of the heat medium according to the condition of the adsorbent.

[0012] (2) In the carbon dioxide recovery device described in (1) above, it is optional that the aforementioned flow adjustment device is composed of the following valves: an upstream four-way valve (for example, the upstream four-way valve 30a described later), which is connected to the upstream side of the aforementioned module and is connected to the aforementioned heat medium pipeline for heating, the aforementioned heat medium pipeline for cooling and the aforementioned bypass pipeline; and a downstream four-way valve (for example, the downstream four-way valve 30b described later), which is connected to the downstream side of the aforementioned module and is connected to the aforementioned heat medium pipeline for heating, the aforementioned heat medium pipeline for cooling and the aforementioned bypass pipeline; the aforementioned control device switches the path of the aforementioned heat medium supplied to the aforementioned module by switching the internal flow paths of the aforementioned upstream four-way valve and the aforementioned downstream four-way valve.

[0013] (3) In the carbon dioxide recovery device described in (1) or (2) above, it is optional that the control device performs the flow control in a manner such that the flow rate in the holding stage is less than the flow rate in the heating stage, the heating stage is a stage in which the adsorbent is heated to the specified temperature of the desorption process by the heat medium supplied from the heating heat medium pipeline, and the holding stage is a stage in which the temperature of the adsorbent, which has reached the specified temperature by the heating, is maintained at the specified temperature.

[0014] (4) In the carbon dioxide recovery device described in (1) or (2) above, it is optional that the control device performs bypass control after the desorption process, and the bypass control is to cool the adsorption element of the first module by the heat medium supplied from the cooling heat medium pipeline, and to supply the heat medium that has cooled the first module to the second module by means of the bypass pipeline, thereby heating the second module.

[0015] (5) In the carbon dioxide recovery device described in (4) above, the control device may optionally perform the following control after the bypass control, that is, the flow rate of the heat medium supplied from the cooling heat medium pipeline to the first module is increased compared with the bypass control.

[0016] (6) In the carbon dioxide recovery device described in (4) above, it is optional that the control device blocks the path from the bypass pipeline to the second module after the bypass control, and supplies the heat medium from the heating heat medium pipeline at a flow rate greater than the flow rate of the heat medium supplied to the second module during the bypass control.

[0017] (Effects of the Invention)

[0018] According to the present invention, a carbon dioxide recovery apparatus can be provided that can accurately perform temperature increase and cooling in the desorption process and the adsorption process using a heat medium at an appropriate flow rate, thereby achieving energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram illustrating a structure related to gas flow in a carbon dioxide recovery device according to one embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram illustrating the structure of the module of the carbon dioxide recovery device according to this embodiment, related to the flow of gas.

[0021] Figure 3 It is a schematic diagram showing the structure of the heat exchange device of the carbon dioxide recovery device according to this embodiment.

[0022] Figure 4 This is a graph showing the relationship between the temperature of the adsorption element of the first module and the supply amount of the heat medium.

[0023] Figure 5 This is a graph showing the relationship between the temperature of the adsorption member of the second module and the supply amount of the heat medium.

[0024] Figure 6 It is a schematic diagram explaining the connection state of the flow paths of the first module and the second module in the first stage.

[0025] Figure 7 It is a schematic diagram explaining the connection state of the flow paths of the first module and the second module in the second stage.

[0026] Figure 8 It is a schematic diagram explaining the connection state of the flow paths of the first module and the second module in the third stage. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0028] <Structures related to gas flow>

[0029] First, refer to Figure 1 and Figure 2 , explaining the structure of recovering carbon dioxide from the atmosphere. Figure 1 It is a schematic diagram showing the structure related to the flow of gas of a carbon dioxide recovery device 1 according to one embodiment of the present invention. Figure 2 It is a schematic diagram showing the structure of the module 11 of the carbon dioxide recovery device 1 according to the present embodiment, which is related to the flow of gas.

[0030] The carbon dioxide recovery device 1 of this embodiment is used, for example, in direct air capture (DAC) technology to recover atmospheric carbon dioxide to reduce atmospheric carbon dioxide concentration. The carbon dioxide recovered by the carbon dioxide recovery device 1 is stored underground or reused as fuel or material.

[0031] like Figure 1 As shown, the carbon dioxide recovery device 1 of this embodiment includes a module unit 10, a fan 61, a vacuum pump 62, a carbon dioxide recovery pump 63, an intercooler 64, a separator 65, a carbon dioxide tank 66, and an inert gas tank 69. In addition, the carbon dioxide recovery device 1 includes an adsorption line 101, a vacuum line 102, a carbon dioxide line 103, a circulation line 104, and an inert gas supply line 107 as gas flow paths. In addition, a heat exchange device 70 for supplying heat to each module 11 and recovering exhaust heat is provided. Figure 1 and Figure 2Illustration omitted.

[0032] The module unit 10 is formed by arranging a plurality of modules 11 for adsorbing carbon dioxide in parallel. In this embodiment, a total of 16 modules 11 are arranged by a pair of left and right module units 10.

[0033] like Figure 2 As shown, module 11 is a carbon dioxide recovery module, which includes an adsorbent 12 , a first valve 21 , a second valve 22 , a third valve 23 , a fourth valve 24 , a pressure sensor 25 , a carbon dioxide sensor 26 and a temperature sensor 27 .

[0034] The adsorbent 12 is disposed within the module 11 to adsorb carbon dioxide. The adsorbent 12 is a particulate component that adsorbs carbon dioxide at low temperatures (e.g., -30°C to 50°C) and desorbs (releases) carbon dioxide at high temperatures (e.g., 50°C to 110°C) when the ambient carbon dioxide concentration is low. Examples of such adsorbents 12 include solid amine carbon dioxide adsorbents composed of amines supported on a porous material such as silica.

[0035] The first valve 21 is an on-off valve located at the connection between the carbon dioxide line 103, which recovers carbon dioxide, and the module 11. A carbon dioxide recovery pump 63 is located on the carbon dioxide line 103. The second valve 22 is an on-off valve located at the connection between the vacuum line 102, which is equipped with the vacuum pump 62, and the module 11. The third valve 23 is an on-off valve located at the inlet for drawing air and other gases into the module 11. The fourth valve 24 is an on-off valve located at the connection between the adsorption line 101 and the module 11.

[0036] The first valve 21, the second valve 22, the third valve 23 and the fourth valve 24 are all opened and closed by the control device 90. The first valve 21, the second valve 22, the third valve 23 and the fourth valve 24 are, for example, normally open butterfly valves.

[0037] The pressure sensor 25 measures the internal pressure of the module 11. The carbon dioxide sensor 26 measures the carbon dioxide concentration inside the module 11. The temperature sensor 27 measures the temperature of the adsorbent 12. The measurement information of the pressure sensor 25, carbon dioxide sensor 26, and temperature sensor 27 is transmitted to the control device 90.

[0038] Back to Figure 1Next, the adsorption line 101 and fan 61 will be described. The adsorption line 101 branches and connects to each module 11. The fan 61 is located at the junction of the branched sections of the adsorption line 101. When the fan 61 is driven, it creates a flow of gas from "intake" to "exhaust" into the module 11 via the adsorption line 101. This allows atmospheric air to be supplied to the module 11. A carbon dioxide concentration sensor 611, a humidity sensor 612, and a temperature sensor 613 are located in the exhaust section of the adsorption line 101 to measure the carbon dioxide, humidity, and temperature discharged from the adsorption line 101. The measurement information from the carbon dioxide concentration sensor 611, humidity sensor 612, and temperature sensor 613 is transmitted to the control device 90.

[0039] The vacuum line 102 branches and connects to each module 11. The vacuum pump 62 is located at the junction of the branched portions of the vacuum line 102. When the vacuum pump 62 is driven, it draws air from the interior of the module 11 through the vacuum line 102, creating a vacuum state or a near-vacuum state within the module 11.

[0040] The carbon dioxide line 103 branches and is connected to each module 11. A carbon dioxide recovery pump 63, an intercooler 64, a separator 65, and a carbon dioxide tank 66 are arranged at a portion where the branched portions of the carbon dioxide line 103 converge.

[0041] The carbon dioxide recovery pump 63 acts as a suction force to transport the carbon dioxide flowing through the carbon dioxide line 103 to the carbon dioxide tank 66. A check valve 631 is disposed upstream of the carbon dioxide recovery pump 63 in the carbon dioxide line 103. This prevents gas from flowing back from the intercooler 64 to the module 11.

[0042] The intercooler 64 is an intermediate cooler that cools the high-temperature gas containing carbon dioxide recovered from the module 11 to separate the gas from the liquid.

[0043] The water separated from the gas and liquid in the intercooler 64 is recovered by the separator 65. The separator 65 is provided with a first valve 651 and a second valve 652. The first valve 651 opens and closes the path communicating with the gas phase of the separator 65. The second valve 652 opens and closes the path communicating with the liquid phase of the separator 65.

[0044] The carbon dioxide tank 66 stores carbon dioxide recovered via the carbon dioxide line 103. A tank valve 661 is disposed upstream of the carbon dioxide tank 66 in the carbon dioxide line 103. The opening and closing of the tank valve 661 is controlled by the control device 90. Furthermore, various sensors, such as a pressure sensor 662, a flow rate sensor 663, a humidity sensor 664, a temperature sensor 665, and a carbon dioxide concentration sensor 666, are disposed between the tank valve 661 and the carbon dioxide tank 66 in the carbon dioxide line 103.

[0045] In addition to the carbon dioxide line 103, the carbon dioxide tank 66 is connected to a circulation line 104 that returns ballast to the carbon dioxide recovery pump 63. A flow rate sensor 667 is provided on the circulation line 104. Furthermore, the carbon dioxide tank 66 is provided with a pressure relief valve 668 that releases pressure when the pressure exceeds a predetermined value.

[0046] Next, the inert gas tank 69 will be described. The inert gas tank 69 stores N2, an inert gas, supplied from an N2 cylinder 691 at a predetermined pressure (e.g., 980 kPa). A cylinder valve 692 is located between the inert gas tank 69 and the N2 cylinder 691. Furthermore, the inert gas tank 69 is equipped with a pressure relief valve 693 that releases pressure when the pressure exceeds a predetermined level. A pressure sensor 694 is located within the inert gas tank 69. Pressure information measured by the pressure sensor 694 is transmitted to the control device 90.

[0047] The inert gas tank 69 is connected to the carbon dioxide line 103 via the inert gas supply line 107. An inert gas valve 695 is provided on the inert gas supply line 107. The inert gas valve 695 is controlled by the control device 90 to be opened and closed.

[0048] <Structure of Heat Exchanger>

[0049] Next, refer to Figure 3 The structure of the heat exchange device 70 will be described. Figure 3 Schematic diagram showing the structure of the heat exchange device 70 of the carbon dioxide recovery device 1 of this embodiment. Figure 3 , among the plurality of modules 11, a first module 11a and a second module 11b are shown, to which heat is supplied and exhaust heat is recovered by the heat exchange device 70. In the following description, common structures that do not distinguish between the first module 11a and the second module 11b may be referred to as modules 11 by omitting the alphabetical letters.

[0050] The heat exchange device 70 supplies heat energy for heating the inside of the module 11 to a predetermined temperature when each module 11 of the module unit 10 performs a desorption process. The heat exchange device 70 also recovers heat energy unnecessary when each module 11 performs an adsorption process.

[0051] The heat exchange device 70 of this embodiment includes a cold water pipeline 111, a cold water circulation water pump 821, a hot water pipeline 112, a hot water circulation water pump 831, a heat source 81, a cold water tank 82, a hot water tank 83, an upstream four-way valve 30a, a downstream four-way valve 30b and a bypass pipeline 31.

[0052] The chilled water line 111 is a pipe that circulates low-temperature chilled water, serving as a cooling medium. The chilled water line 111 branches to connect to the upstream and downstream sides of each module 11, connecting the chilled water tank 82 to each module 11. The line connected to the upstream side of each module 11 is designated as the outbound chilled water line 111a, while the line connected to the downstream side of each module 11 is designated as the return chilled water line 111b.

[0053] The outbound chilled water pipeline 111a is connected in parallel to multiple modules 11, allowing the supply of chilled water to be paralleled per module 11. The chilled water flowing from the outbound chilled water pipeline 111a into the modules 11 is a relatively high-pressure heat medium because it passes before the modules 11. The return chilled water pipeline 111b is also connected in parallel to multiple modules 11, allowing the recovery of the chilled water after cooling to be paralleled per module 11. The chilled water flowing from the modules 11 into the return chilled water pipeline 111b is a relatively low-pressure heat medium because it passes after the modules 11.

[0054] The cold water circulation pump 821 is disposed in the cold water pipeline 111. The cold water circulation pump 821 is, for example, a cascade pump. The cold water circulates in the cold water pipeline 111 through the cold water circulation pump 821.

[0055] The hot water line 112 is a pipe that circulates high-temperature hot water, serving as a heat medium for heating. The hot water line 112 branches to connect to the upstream and downstream sides of each module 11, connecting the hot water tank 83 to each module 11. The line connected to the upstream side of each module 11 within the hot water line 112 is designated as the outbound hot water line 112a, while the line connected to the downstream side of each module 11 is designated as the return hot water line 112b.

[0056] The outbound hot water pipeline 112a is connected in parallel to multiple modules 11, and the supply of hot water can also be carried out in parallel according to the modules 11. The hot water flowing from the outbound hot water pipeline 112a to the modules 11 is a relatively high-temperature, high-pressure heat medium because it passes through the modules 11 before. The return hot water pipeline 112b is also connected in parallel to multiple modules 11, and the recovery of the heated hot water can also be carried out in parallel according to the modules 11. The hot water flowing from the modules 11 to the return hot water pipeline 112b is a relatively low-pressure heat medium because it passes through the modules 11 after.

[0057] The hot water circulation pump 831 is disposed in the hot water line 112. The hot water circulation pump 831 is, for example, a cascade pump. The hot water circulation pump 831 circulates hot water in the hot water line 112.

[0058] The heat source 81 cools the heat medium introduced from the cold water tank 82 and heats the medium introduced from the warm water tank 83. The heat source 81 is formed of a heat pump that transfers heat by utilizing the compression and expansion of gas.

[0059] The cold water tank 82 stores the cold water flowing through the cold water line 111. The cold water flowing through the cold water line 111 is stored in the cold water tank 82 and then transported to the heat source 81. Furthermore, the cold water cooled by the heat source 81 returns to the cold water tank 82 and is then transported to each module 11 via the cold water line 111.

[0060] The warm water tank 83 stores the warm water flowing through the warm water line 112. After being stored in the warm water tank 83, the warm water flowing through the warm water line 112 is transported to the heat source 81. Furthermore, the heat medium heated by the heat source 81 returns to the warm water tank 83 and is then transported to each module 11 via the warm water line 112.

[0061] The upstream four-way valve 30a is a flow switching device located upstream of each module 11. It has a flow control function, regulating the flow rate of the fluid passing through it. The cold water outflow line 111a, the hot water outflow line 112a, and the bypass line 31 are connected to the upstream four-way valve 30a.

[0062] The upstream four-way valve 30a of this embodiment has an internal flow path that can switch between a cold water connection state, a warm water connection state and a bypass connection state. The cold water connection state is to connect the cold water outgoing pipeline 111a to the module 11, the warm water connection state is to connect the warm water outgoing pipeline 112a to the module 11, and the bypass connection state is to connect the bypass pipeline 31 to the module 11.

[0063] The downstream four-way valve 30b is a flow switching device located downstream of each module 11. It has a flow control function, regulating the flow rate of the fluid passing through it. The cold water return line 111b, the hot water return line 112b, and the bypass line 31 are connected to the downstream four-way valve 30b.

[0064] The downstream four-way valve 30b of this embodiment has an internal flow path that can switch between the cold water connection state, the warm water connection state and the bypass connection state. The cold water connection state is to connect the cold water return pipeline 111b to the module 11, the warm water connection state is to connect the warm water return pipeline 112b to the module 11, and the bypass connection state is to connect the bypass pipeline 31 to the module 11.

[0065] The bypass line 31 is a flow path that allows the heat medium to flow between modules 11. The bypass line 31 connects two modules 11. The modules 11 connected by the bypass line 31 can be adjacent modules or modules 11 that are not adjacent but are located at a distance. Figure 3 In the example, one end of the bypass line 31 is connected to the downstream four-way valve 30b of the first module 11a, and the other end is connected to the upstream four-way valve 30a of the second module 11b.

[0066] Furthermore, it is assumed that the bypass line 31 connected to the upstream four-way valve 30a of the first module 11a is connected to the downstream four-way valve 30b of the module 11 (not shown) located on the left side of the drawing. Furthermore, it is assumed that the bypass line 31 connected to the downstream four-way valve 30b of the second module 11b is connected to the upstream four-way valve 30a of the module 11 (not shown) located on the right side of the drawing.

[0067] The flow path switching of the upstream four-way valve 30a and the downstream four-way valve 30b is controlled by the control device 90. When warm water flows through the module 11, the upstream four-way valve 30a connects the warm water outflow line 112a to the upstream side of the module 11, and the downstream four-way valve 30b connects the warm water return line 112b to the downstream side of the module 11. When cold water flows through the module 11, the upstream four-way valve 30a connects the cold water outflow line 111a to the upstream side of the module 11, and the downstream four-way valve 30b connects the cold water return line 111b to the downstream side of the module 11.

[0068] Furthermore, in the bypass connection state, the downstream side of the first module 11a and the upstream side of the second module 11b are connected via a bypass line 31 via a four-way valve 30b on the downstream side of the first module 11a and a four-way valve 30a on the upstream side of the second module 11b. This allows the heat medium (warm water or cold water) that has passed through the first module 11a to flow to the second module 11b via the bypass line 31.

[0069] Next, the control device 90 will be described. The control device 90 controls the operation of various components of the carbon dioxide recovery apparatus 1. The control device 90 controls the driving and stopping of devices used for carbon dioxide adsorption and desorption. To enable multiple modules 11 to repeatedly perform adsorption and desorption in a timed sequence, the control device 90 selectively controls the timing of supplying heat medium to each module 11 for heating and cooling.

[0070] The control device 90 controls the opening and closing of the first valve 21, the second valve 22, the third valve 23, and the fourth valve 24, as well as the opening and closing of the upstream four-way valve 30a and the downstream four-way valve 30b, included in each module 11. The control device 90 also controls the driving of the fan 61, the vacuum pump 62, the carbon dioxide recovery pump 63, the cold water circulation pump 821, the warm water circulation pump 831, and the like.

[0071] The control device 90 is a computer having, for example, a central processing unit (CPU), read-only memory (ROM), and random access memory (RAM). The control device 90 may be composed of a single unit or multiple units. Furthermore, the control device 90 may be constructed using circuits such as relays.

[0072] <Carbon dioxide recovery>

[0073] Next, the control performed by the controller 90 for recovering carbon dioxide will be described. The carbon dioxide recovery device 1 alternates between an adsorption process, in which carbon dioxide from the inhaled atmosphere, etc., is adsorbed onto the adsorbent 12 within the module 11, and a desorption process, in which the carbon dioxide adsorbed by the adsorbent 12 is desorbed. The desorbed carbon dioxide is compressed and stored in a tank (not shown), thereby removing and recovering carbon dioxide from the air. In this embodiment, the adsorption and desorption processes are performed with a ratio of adsorption time to desorption time of 3:1.

[0074] The adsorption process is a process of adsorbing carbon dioxide on the adsorbent 12 in the module 11. In the adsorption process, the third valve 23 and the fourth valve 24 of the module 11 are opened, and the first valve 21 and the second valve 22 are closed. The fan 61 is driven, and the gas flows from upstream to downstream, and the gas containing carbon dioxide (such as the atmosphere) is sucked in through the third valve 23. The sucked gas passes through the adsorbent 12 in the module 11. At this time, the temperature inside the module 11 is normal temperature (25°C), and the carbon dioxide in the gas is adsorbed on the adsorbent 12. Gases other than carbon dioxide, such as nitrogen or oxygen, pass through the fourth valve 24 and the adsorption pipeline 101 and are discharged to the outside of the carbon dioxide recovery device 1.

[0075] The desorption process desorbs carbon dioxide from the adsorbent 12 within the module 11. During the desorption process, the first valve 21, third valve 23, and fourth valve 24 of the module 11 are closed, and the second valve 22 is opened. The vacuum pump 62 operates, sucking air into the interior of the module 11, thereby reducing the pressure and bringing it to a vacuum state or a near-vacuum state. Simultaneously, a heat medium, acting as a heat source, flows through the module 11 via the heat exchange device 80, supplying heat energy and raising the temperature of the adsorbent 12 within the module 11. The temperature control performed by the heat exchange device 80 will be described below.

[0076] By controlling the temperature rise of the adsorbent 12, the adsorbent 12 is also heated to a predetermined temperature (e.g., 80°C) sufficient for the desorption process, thereby desorbing the carbon dioxide adsorbed on the adsorbent 12. Next, the second valve 22, the third valve 23, and the fourth valve 24 are closed, the first valve 21 is opened, and the carbon dioxide recovery pump 63 is activated. The desorbed carbon dioxide is stored in a tank (not shown) via the carbon dioxide pipeline 103. In this embodiment, the various processes are controlled so that 12 of the 16 modules 11 perform the adsorption process, while the remaining 4 perform the desorption process.

[0077] Switching control and flow control

[0078] Next, the flow path switching control and flow rate control performed by the control device 90 according to each stage (condition) of the adsorption or desorption process will be described. In the flow rate control performed by the control device 90, the openings of the upstream four-way valve 30a and the downstream four-way valve 30b are feedback-controlled in a manner appropriate to the time-varying curve of the temperature of the target adsorption member 12.

[0079] In addition, the control device 90 can judge the various stages of the adsorption part 12 based on the temperature of the adsorption part 12 obtained from the temperature sensor 27, or based on the detection values ​​of various sensors such as the pressure sensor 25, or use the elapsed time in a timer, etc. to judge the various stages of the adsorption part 12.

[0080] Figure 4 Graph showing the relationship between the temperature of the adsorption member 12 of the first module 11 a and the supply amount of the heat medium. Figure 5 is a graph showing the relationship between the temperature of the adsorption member 12 of the second module 11b and the supply amount of the heat medium. Figure 4 The stages shown are Figure 5 The first module 11a and the second module 11b execute the processes in parallel. In addition, the first stage, the second stage, and the third stage are the order in the diagram. For example, Figure 4 The first stage in the carbon dioxide recovery device 1 does not represent the initial state of the adsorbent 12, but rather represents the state of the adsorbent 12 after the adsorption of carbon dioxide in the time series. Figure 4 The temperature rise control performed before the graph reaches the state of the desorption process.

[0081] First, for Figure 4 The control of the first stage on the first module 11a side will be described. In the first stage on the first module 11a side, a desorption process is performed. In this desorption process, the adsorbent 12 reaches 80°C by the temperature increase control performed in advance.

[0082] Figure 6 Schematic diagram illustrating the connection state of the flow paths of the first module 11a and the second module 11b in the first stage. Figure 6 As shown, in the first stage, the upstream four-way valve 30a and the downstream four-way valve 30b are controlled to the warm water connection state. As a result, the warm water outflow line 112a is connected to the upstream side of the first module 11a, and the downstream side of the first module 11a is connected to the warm water return line 112b.

[0083] exist Figure 4 In the first stage shown in the graph, since the temperature of the adsorption member 12 has reached 80°C, the supply amount of hot water only needs to be enough to maintain the temperature of the adsorption member 12. Therefore, the control device 90 of the first stage controls the opening of the upstream four-way valve 30a and the downstream four-way valve 30b of the first module 11a to reduce the opening of the upstream four-way valve 30a and the downstream four-way valve 30b so that the opening of the first module 11a becomes smaller than that of the first module 11a. Figure 4 The flow rate (eg, 10 l / min) in the previous temperature increase stage shown in the graph is a relatively small flow rate (eg, 5 l / min).

[0084] On the other hand, Figure 5In the first stage shown on the second module 11b side, the vacuum pump 62 is used to purge the O2 inside the second module. The temperature of the adsorbent 12 of the second module 11b is maintained at room temperature, for example, below 30°C. During the O2 purge, the control device 90 controls the upstream four-way valve 30a and the downstream four-way valve 30b to control the second module 11b to the following state: all paths of the cold water line 111, the hot water line 112, and the bypass line 31 are blocked, preventing the flow of heat medium.

[0085] Next, the second stage will be described. Figure 4 As shown, in the first module 11a of the second stage, the desorption process is completed and pre-cooling (series) begins. The series mentioned here means that the cold water passes through the first module 11a and then passes through the second module 11b.

[0086] Figure 7 Schematic diagram illustrating the connection state of the flow paths of the first module 11a and the second module 11b in the second stage. Figure 7 As shown, the control device 90 controls the upstream four-way valve 30a to the cold water connection state and the downstream four-way valve 30b to the bypass connection state. As a result, the cold water outbound pipeline 111a is connected to the upstream side of the first module 11a, and the downstream side of the first module 11a is connected to the bypass line 31.

[0087] like Figure 5 As shown, in the second module 11b of the second stage, the O2 purge is completed and the first temperature increase control is started. The first temperature increase control is performed to increase the temperature of the adsorbent 12 from room temperature to about 50°C.

[0088] like Figure 7 As shown, the second-stage control device 90 controls the upstream four-way valve 30a to the bypass connection state and the downstream four-way valve 30b to the cold water connection state. As a result, the bypass line 31 is connected to the upstream side of the second module 11b, and the downstream side of the second module 11b is connected to the cold water return line 111b.

[0089] In the first module 11a of the second stage, cold water from the outbound cold water line 111a is introduced to the upstream side of the first module 11a, gradually cooling the temperature of the adsorbent 12 of the first module 11a from 80°C to 50°C. The cold water flowing out of the downstream side of the first module 11a receives heat from the adsorbent 12 while passing through the first module 11a, reaching a higher temperature than before introduction into the first module 11a.

[0090] Meanwhile, in the second module 11b during the second stage, water (bypass water) that has passed through the first module 11a is introduced upstream of the second module 11b via the bypass line 31. The bypass water gradually raises the temperature of the adsorbents 12 in the second module 11b from room temperature to approximately 50°C. In this manner, heat is transferred from the first module 11a to the second module 11b during the second stage.

[0091] The second stage of precooling the first module 11a and heating the second module 11b is an intermediate stage toward the final target temperature, requiring a relatively low flow rate. Therefore, during the second stage, the control device 90 controls the flow rate by narrowing the openings of the upstream four-way valve 30a and downstream four-way valve 30b of the first module 11a, and the upstream four-way valve 30a and downstream four-way valve 30b of the second module 11b, respectively, to a relatively low flow rate (e.g., 5 l / min).

[0092] Next, the third stage will be described. Figure 4 As shown, pre-cooling (parallel) is performed in the first module 11a in the third stage. Parallel here means that heat medium (cold water and warm water) is supplied in parallel to each of the first module 11a and the second module 11b.

[0093] Figure 8 Schematic diagram illustrating the connection state of the flow paths of the first module 11a and the second module 11b in the third stage. Figure 8 As shown, the third-stage control device 90 controls the upstream four-way valve 30a and downstream four-way valve 30b of the first module 11a to the cold water connection state. This results in the following state: the outbound cold water line 111a is connected to the upstream side of the first module 11a, and the downstream side of the first module 11a is connected to the return cold water line 111b. Low-temperature cold water in the outbound cold water line 111a is introduced into the first module 11a, cooling the adsorbent 12 of the first module 11a from 50°C to approximately 30°C.

[0094] The pre-cooling (parallel) of the first module 11a in the third stage is a process of cooling the temperature of the adsorption member 12 of the first module 11a from 50°C to the target temperature (30°C). The control device 90 controls the opening of the upstream four-way valve 30a and the downstream four-way valve 30b of the first module 11a so as to achieve a flow rate greater than that of the pre-cooling (serial) in the second stage (for example, 10 l / min).

[0095] like Figure 5 As shown, in the second module 11b of the third stage, the first temperature increase control ends and the second temperature increase control begins. The second temperature increase control is performed to increase the temperature of the adsorbent 12 from about 50°C to 80°C, which is the target temperature for the desorption process.

[0096] like Figure 8 As shown, in the third stage, the control device 90 controls the upstream and downstream four-way valves 30a and 30b of the second module 11b to the warm water connection state. This results in the following state: the outbound warm water line 112a is connected to the upstream side of the second module 11b, and the downstream side of the second module 11b is connected to the return warm water line 112b. The high-temperature warm water in the outbound warm water line 112a is introduced into the second module 11b, gradually raising the temperature of the adsorbent 12 in the second module 11b from 50°C to 80°C.

[0097] The second temperature rise control of the second module 11b in the third stage is a process of heating the temperature of the adsorption member 12 of the second module 11b from 50°C to the target temperature (80°C). The control device 90 controls the opening of the upstream four-way valve 30a and the downstream four-way valve 30b of the second module 11b so as to make the flow rate greater than that of the first temperature rise control of the second stage (for example, 10 l / min).

[0098] As described above, the carbon dioxide recovery device 1 of this embodiment comprises: a plurality of modules 11, each having an adsorbent 12 inside, and performing an adsorption process and a desorption process, wherein the adsorption process is to attract a gas containing carbon dioxide to the adsorbent 12 so that the adsorbent 12 adsorbs carbon dioxide, and the desorption process is to desorb carbon dioxide from the adsorbent 12 by heating the area around the adsorbent 12 under a reduced pressure state; a warm water pipeline (heat medium pipeline for heating) 112, for supplying relatively high-temperature warm water (heat medium) to each of the plurality of modules 11 so as to heat the adsorbent 12 performing the desorption process; a cold water pipeline (heat medium pipeline for cooling) 111, for supplying relatively low-temperature heat medium (cold water) so as to cool the adsorbent 12 performing the adsorption process; a heat source 81, which can cool the adsorbent 12 performing the adsorption process by heating the area around the adsorbent 12 under a reduced pressure state; The hot water of the hot water line 112 is heated, and the cold water flowing through the cold water line 111 is cooled; the bypass line 31 can introduce the heat medium that has passed through one of the multiple modules 11, that is, the first module 11a, to the second module 11b different from the first module 11a; the upstream four-way valve 30a and the downstream four-way valve 30b (flow adjustment device) are arranged in each of the modules 11, and can switch the path of the heat medium supplied to the module 11 from the hot water line 112, the cold water line 111 or the bypass line 31, and adjust the flow rate of the heat medium passing through the module 11; and the control device 90 changes the switching control for switching the path of the heat medium and the flow control for adjusting the flow rate of the heat medium according to the condition of the adsorption member 12 by controlling the upstream four-way valve 30a and the downstream four-way valve 30b.

[0099] This allows exhaust heat recovery between the first module 11a and the second module 11b. Highly efficient heat transfer between the first and second modules 11a and 11b reduces the electrical energy required to heat a heat medium such as warm water. Furthermore, the flow rate can be varied at each stage of the adsorption and desorption processes. By selecting the appropriate flow rate based on the state of the adsorbent 12, the required amount of water can be supplied appropriately. Furthermore, pressure loss (required head) is proportional to the square of the flow rate, and the work performed by the cold water circulating pump 821 and the hot water circulating pump 831 is proportional to the product of the head and the flow rate. Without adjusting the opening, the hot and cold water heat media always flow at their maximum flow rate. However, in this embodiment, the flow rate can be reduced according to the stage, significantly reducing pump work and improving the energy efficiency of the carbon dioxide recovery device 1.

[0100] In addition, in this embodiment, the flow adjustment device is composed of the following valves: an upstream four-way valve 30a, which is connected to the upstream side of the module 11 and is connected to the hot water pipeline 112, the cold water pipeline 111 and the bypass pipeline 31; and a downstream four-way valve 30b, which is connected to the downstream side of the module 11 and is connected to the hot water pipeline 112, the cold water pipeline 111 and the bypass pipeline 31; the control device 90 switches the path of the heat medium supplied to the module 11 by switching the internal flow paths of the upstream four-way valve 30a and the downstream four-way valve 30b.

[0101] Thus, the upstream four-way valve 30a and the downstream four-way valve 30b can be used to control the switching of the heat medium supplied via the hot water line 112, the cold water line 111, and the bypass line 31. It is also unnecessary to provide flow rate adjustment functions in the hot water line 112, the cold water line 111, and the bypass line 31, respectively. Therefore, a structure for changing the flow rate of the heat medium supplied to the adsorption element 12 according to the temperature potential can be realized with a simple structure.

[0102] In addition, in this embodiment, the control device 90 controls the flow rate in a manner such that the flow rate in the maintaining stage is less than the flow rate in the heating stage. The heating stage is a stage in which the adsorbent 12 is heated to a specified temperature of the desorption process by means of warm water supplied from the warm water pipeline 112, and the maintaining stage is a stage in which the temperature of the adsorbent 12 that has reached the specified temperature by heating is maintained at the specified temperature.

[0103] Therefore, in order to maintain the temperature, the flow rate of the heat medium supplied to the module 11 can be reduced in the desorption process where the required flow rate is small compared to the temperature increase stage, thereby reducing the work of the warm water circulation pump 831.

[0104] In addition, in this embodiment, the control device 90 performs bypass control after the desorption process, and the bypass control cools the adsorption component 12 of the first module 11a by supplying cold water from the cold water pipeline 111, and supplies the cold water that has cooled the first module 11a to the second module 11b by means of the bypass pipeline 31, thereby heating the second module 11b.

[0105] Thus, the adsorbent 12 of the second module 11b can be heated by the cold water, which has received heat from cooling the adsorbent 12 of the first module 11a. Since the temperature can be raised by recovering exhaust heat, without the need for external heat supply, energy efficiency can be further improved.

[0106] In the present embodiment, after the bypass control, the control device 90 performs control such that the flow rate of the chilled water supplied from the chilled water line 111 to the first module 11 a is increased compared to the bypass control.

[0107] Thus, during bypass control, bypass water can be supplied from the first module 11a to the second module 11b at the flow rate required by the second module 11b while suppressing the work of the chilled water circulating pump 821. Furthermore, after bypass control, the chilled water flow rate increases, allowing the adsorption element 12 of the first module 11a to be quickly heated to the desired temperature.

[0108] Furthermore, in this embodiment, after bypass control, the control device 90 blocks the path from the bypass line 31 to the second module 11b and supplies heat medium from the hot water line 112 at a flow rate greater than the flow rate of heat medium supplied to the second module 11b during bypass control. Furthermore, after bypass control, high-temperature, high-flow hot water is supplied to the second module 11b, allowing the adsorbent 12 of the second module 11b to be quickly cooled to room temperature.

[0109] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. In addition, the effects described in the above embodiments are only preferred effects and are not limited to the effects described in the above embodiments.

[0110] Reference numerals

[0111] 1 Carbon dioxide recovery device

[0112] 11 modules

[0113] 11a Module 1

[0114] 11b Module 2

[0115] 12 Adsorption parts

[0116] 30a Upstream four-way valve

[0117] 30b Downstream four-way valve

[0118] 31 Bypass line

[0119] 81 Heat Source

[0120] 90 Control Device

[0121] 111 Cold water pipeline

[0122] 111a Cold water outbound pipeline

[0123] 111b Cold water return line

[0124] 112 warm water pipeline

[0125] 112a Warm water outbound pipeline

[0126] 112b Warm water return line

Claims

1. A carbon dioxide recovery device comprising: The modules each have an adsorbent therein and perform an adsorption process and a desorption process. The adsorption process involves drawing a gas containing carbon dioxide into the adsorbent so that the adsorbent adsorbs the carbon dioxide. The desorption process involves heating the area surrounding the adsorbent under reduced pressure to desorb the carbon dioxide from the adsorbent. a heating heat medium pipeline for supplying a relatively high-temperature heat medium to each of the plurality of modules so as to heat the adsorption element performing the desorption process; a cooling heat medium pipeline for supplying a relatively low-temperature heat medium to cool the adsorption element during the adsorption process; a heat source capable of heating the heat medium flowing through the heating heat medium pipeline and cooling the heat medium flowing through the cooling heat medium pipeline; a bypass line capable of directing the heat medium having passed through one of the plurality of modules, namely the first module, to a second module different from the first module; a flow control device, disposed in each of the modules, capable of switching the path of the heat medium supplied to the module from the heating heat medium line, the cooling heat medium line, or the bypass line, and adjusting the flow rate of the heat medium passing through the module; and The control device controls the flow rate adjustment device to change the switching control for switching the path of the heat medium and the flow rate control for adjusting the flow rate of the heat medium according to the condition of the adsorption member.

2. The carbon dioxide recovery device according to claim 1, wherein: The aforementioned flow control device is composed of the following valves: an upstream four-way valve connected to the upstream side of the module and connected to the heating heat medium pipeline, the cooling heat medium pipeline and the bypass pipeline; and A downstream four-way valve connected to the downstream side of the module and connected to the heating heat medium pipeline, the cooling heat medium pipeline and the bypass pipeline; The control device switches the path of the heat medium supplied to the module by switching internal flow paths of the upstream four-way valve and the downstream four-way valve.

3. The carbon dioxide recovery device according to claim 1 or 2, wherein: The control device performs the flow control in such a manner that the flow rate in the holding phase is less than the flow rate in the heating phase. The heating phase is a phase in which the adsorbent is heated to a predetermined temperature of the desorption process by the heat medium supplied from the heating heat medium pipeline. The holding phase is a phase in which the temperature of the adsorbent, which has reached the predetermined temperature by the heating, is maintained at the predetermined temperature.

4. The carbon dioxide recovery device according to claim 1 or 2, wherein: The control device performs bypass control after the desorption process, wherein the bypass control cools the adsorption element of the first module by means of the heat medium supplied from the cooling heat medium pipeline, and supplies the heat medium that has cooled the first module to the second module by means of the bypass pipeline, thereby raising the temperature of the second module.

5. The carbon dioxide recovery device according to claim 4, wherein: The control device performs control after the bypass control so as to increase the flow rate of the heat medium supplied from the cooling heat medium line to the first module compared to the bypass control.

6. The carbon dioxide recovery device according to claim 4, wherein: The control device blocks the path from the bypass line to the second module after the bypass control, and supplies the heat medium from the heating heat medium line at a flow rate greater than the flow rate of the heat medium supplied to the second module during the bypass control.

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