Carbon dioxide recovery device

Abstract

The problem to be solved by the present invention is to provide a carbon dioxide recovery device which is capable of suppressing the energy required for the temperature rise of an adsorbent material in a desorption step and has high energy efficiency. [Solution] A carbon dioxide recovery device (1) is provided with: a plurality of modules (11) having an adsorbent (12) therein, the modules (11) executing an adsorption step for adsorbing carbon dioxide by suctioning a gas containing carbon dioxide into the adsorbent (12), and a desorption step for desorbing the carbon dioxide by suctioning the gas containing carbon dioxide into the adsorbent (12); a desorption step for desorbing carbon dioxide from the adsorption material 12 by heating the periphery of the adsorption material 12 in a reduced pressure state; a heat exchange device (80) for supplying heat for heating the adsorbent (12) to each of the plurality of modules (11) via a heat medium; and a bypass path (31) that connects a first module (11A), which is one of the plurality of modules (11), and a second module (11B), which is different from the first module (11A), and through which a heat medium can flow.

Description

Technical Field

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

[0002] Conventionally, a technique for recovering carbon dioxide from a gas containing carbon dioxide such as the atmosphere has been known. As a document describing such a technique, for example, there is Patent Document 1. In Patent Document 1, the following method is described: gaseous carbon dioxide is separated from a gas mixture by performing cyclic adsorption / desorption using an adsorbent that adsorbs gaseous carbon dioxide.

[0003] [Prior Art Documents]

[0004] (Patent Document)

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

[0006] [Problems to be Solved by the Invention]

[0007] However, in the desorption step of desorbing the carbon dioxide adsorbed by the adsorbent from the adsorbent, it is necessary to make the adsorbent in a high-temperature state. In order to raise the temperature of the adsorbent from room temperature to a temperature at which desorption can be performed, a large amount of external heat energy is required. In the prior art, there is still room for improvement in terms of improving the energy efficiency required for raising the temperature of the adsorbent.

[0008] An object of the present invention is to provide a carbon dioxide recovery device that can suppress the energy required for raising the temperature of the adsorbent in the desorption step and has high energy efficiency.

[0009] [Technical Means for Solving the Problems]

[0010] (1) The present invention is a carbon dioxide recovery device (for example, the following carbon dioxide recovery device 1), comprising: a plurality of modules (for example, the following module 11), which have an adsorbent (for example, the following adsorbent 12) inside and perform an adsorption step and a desorption step, the adsorption step being to attract a gas containing carbon dioxide to the adsorbent to adsorb the carbon dioxide, and the desorption step being to desorb the carbon dioxide from the adsorbent by heating the periphery of the adsorbent under a reduced pressure state; a heat exchange device (for example, the following heat exchange device 80), which supplies heat for heating the adsorbent to each of the plurality of modules via a heat medium; and a bypass path (for example, the following bypass path 31), which connects a first module (for example, the following first module 11A) that is one of the plurality of modules and a second module (for example, the following second module 11B) different from the first module, and through which the heat medium can flow.

[0011] (2) The carbon dioxide recovery device according to (1) above, wherein the heated medium after cooling the first module after the desorption step can also be supplied to the second module to be heated in the desorption step via the bypass path, whereby heat is supplied from the first module to the second module.

[0012] (3) The carbon dioxide recovery device according to (1) or (2) above, wherein the carbon dioxide recovery device may further include a warm water tank (for example, the following warm water tank 83), which is arranged between the heat exchange device and the module and stores warm water as the heated medium.

[0013] (4) The carbon dioxide recovery device according to (3) above, wherein the adsorbent may be heated by two-stage heating. The two-stage heating is to supply heat from the first module to the second module via the bypass path to heat the adsorbent, and then supply heat from the warm water tank to the second module to heat the adsorbent.

[0014] (5) The carbon dioxide recovery device according to (4) above, wherein when the temperature difference between the adsorbent in the first module during the cooling process after the desorption step and the adsorbent in the second module to be heated in the desorption step is equal to or greater than a certain value, heat is supplied from the first module to the second module via the bypass path. If the temperature difference between the adsorbent in the first module during the cooling process and the adsorbent in the second module to be heated is lower than the certain value, the bypass path is closed and heat supply from the warm water tank is started.

[0015] (6) The carbon dioxide recovery device according to (1) or (2) above, wherein the carbon dioxide recovery device may further include: a fan (for example, the following fan 61) for supplying gas to the inside of the module; a heat source (for example, the following heat exchange device 80) for supplying heat for heating the adsorbent in the module; and a vacuum pump (for example, the following vacuum pump 62, carbon dioxide recovery pump 63) for sucking the gas inside the module. And at least one of the fan, the heat source, and the vacuum pump is shared by the plurality of modules. If a natural number is set as N and the ratio obtained by dividing the adsorption time of the adsorbent by the desorption time is set as R, the number M of the modules connected in series by the bypass path is set based on the following mathematical formula (1):

[0016] M = N × (R + 1) Mathematical formula (1).

[0017] (Effects of the invention)

[0018] According to the present invention, a carbon dioxide recovery device can be provided, which can suppress the energy required for heating the adsorbent material in the desorption process and has high energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram showing the configuration related to the flow of liquid in a carbon dioxide recovery device according to an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram showing the configuration related to the flow of gas in a module of the carbon dioxide recovery device according to the present embodiment.

[0021] Figure 3 It is a schematic diagram showing the heat supply path in the first stage of heating the adsorbent material.

[0022] Figure 4 It is a schematic diagram showing the heat supply path in the second stage of heating the adsorbent material.

[0023] Figure 5 It is a schematic diagram showing the heat supply path in the third stage of heating the adsorbent material.

[0024] Figure 6 It is a diagram for explaining the heat transfer between the first module and the second module during the heating process of the adsorbent material.

[0025] Figure 7 It is a diagram for explaining the heat transfer between the first module and the second module during the heating process of the adsorbent material in the prior art without a bypass path.

[0026] Figure 8 It is a flowchart showing an example of the processing flow of the temperature rise control performed by the carbon dioxide recovery device according to the present embodiment.

[0027] Figure 9 It is a schematic diagram showing the relationship between the cycle of repeating the adsorption process and the desorption process and the heat transfer between multiple modules.

[0028] Figure 10 It is a schematic diagram showing the numbers assigned to the modules of the carbon dioxide recovery device according to the present embodiment.

[0029] Figure 11 It is a diagram showing the heat transfer between 16 modules according to the present embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0031] <OVERALL CONFIGURATION>

[0032] Figure 1It is a schematic diagram showing the configuration related to the flow of liquid in the carbon dioxide recovery device 1 according to an embodiment of the present invention. Figure 2 It is a schematic diagram showing the configuration related to the flow of gas in the module 11 of the carbon dioxide recovery device 1 of the present embodiment. In addition, in Figure 1 the illustration of the configuration related to the flow of gas in the carbon dioxide recovery device 1 is omitted.

[0033] The carbon dioxide recovery device 1 of the present embodiment is applied, for example, to the direct air capture technology (DAC: Direct Air Capture) for recovering carbon dioxide in the atmosphere to reduce the concentration of carbon dioxide in the atmosphere. The carbon dioxide recovered by the carbon dioxide recovery device 1 is stored underground or reused as fuel or materials.

[0034] As Figure 1 and Figure 2 shown, the carbon dioxide recovery device 1 of the present embodiment includes a module unit 10, a fan 61, a vacuum pump 62, a carbon dioxide recovery pump 63, and a heat exchange device 80.

[0035] The module unit 10 is composed of a plurality of modules 11 for adsorbing carbon dioxide arranged in parallel. In the present embodiment, a total of 16 modules 11 are arranged by a pair of module units 10 on the left and right.

[0036] As Figure 2 shown, the module 11 is a carbon dioxide recovery module, and includes an adsorbent 12, a first valve 21, a second valve 22, a third valve 23, a fourth valve 24, and a temperature sensor 27.

[0037] The adsorbent 12 is arranged inside the module 11 to adsorb carbon dioxide. The adsorbent 12 is a granular member and has the following properties: it adsorbs carbon dioxide in a low-temperature state (for example, in the range of -30°C to 50°C), and desorbs (releases) carbon dioxide in a high-temperature state (for example, in the range of 50°C to 110°C) and when the concentration of carbon dioxide around is low. As such an adsorbent 12, for example, a solid amine carbon dioxide adsorbent formed by supporting an amine on a porous material such as silica can be cited.

[0038] The first valve 21 is a switching valve arranged at the connection part between the carbon dioxide pipeline 103 for recovering carbon dioxide and the module 11. A carbon dioxide recovery pump 63 is arranged on the carbon dioxide pipeline 103. The second valve 22 is a switching valve arranged at the connection part between the vacuum pipeline 102 provided with the vacuum pump 62 and the module 11. The third valve 23 is a switching valve arranged at the entrance for sucking air or the like into the inside of the module 11. The fourth valve 24 is a switching valve arranged at the connection part between the adsorption pipeline 101 and the module 11. A fan 61 is arranged on the adsorption pipeline 101.

[0039] The opening and closing of the first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are all controlled by the control device 90. The first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 are constituted by, for example, normally open butterfly valves. The temperature sensor 27 measures the temperature of the adsorption material 12. The measurement information of the temperature sensor 27 is sent to the control device 90.

[0040] The adsorption pipeline 101 branches and is respectively connected to each module 11. The fan 61 is disposed at a portion where the branched portions of the adsorption pipeline 101 converge. The fan 61 is driven so that the gas from "suction" to "exhaust" flows relative to the module 11 through the adsorption pipeline 101. Thereby, the atmosphere is supplied into the module 11.

[0041] The vacuum pipeline 102 branches and is respectively connected to each module 11. The vacuum pump 62 is disposed at a portion where the branched portions of the vacuum pipeline 102 converge. The vacuum pump 62 is driven to suck the gas inside the module 11 through the vacuum pipeline 102, making the inside of the module 11 in a vacuum state or near-vacuum state.

[0042] The carbon dioxide pipeline 103 branches and is respectively connected to each module 11. At a portion where the branched portions of the carbon dioxide pipeline 103 converge, a carbon dioxide recovery pump 63 is disposed. The carbon dioxide recovery pump 63 exerts an attraction on the carbon dioxide flowing in the carbon dioxide pipeline 103 to store the recovered carbon dioxide in a not-shown tank for storing carbon dioxide.

[0043] Return Figure 1 The heat exchange device 80 will be described. When each module 11 of the module unit 10 performs the desorption process, the heat exchange device 80 supplies thermal energy for heating the inside of the module 11 to a specific temperature. In addition, the heat exchange device 80 recovers the thermal energy that is not required when each module 11 performs the adsorption process.

[0044] The heat exchange device 80 of the present embodiment includes a heat exchanger 81, a cold water tank 82, a cold water pipeline 111, a warm water tank 83, a warm water pipeline 112, a three-way valve 30, a bypass path 31, and a bypass valve 32.

[0045] The heat exchanger 81 exchanges heat between the heat medium flowing in the cold water pipeline 111 and the heat medium flowing in the warm water pipeline 112. The heat exchanger 81 is, for example, a heat pump. The heat medium is, for example, a liquid such as water. By the heat transfer generated in the heat exchanger 81, the heat medium flowing in the cold water pipeline 111 is cooled, and the heat medium flowing in the warm water pipeline 112 is heated.

[0046] The cold water tank 82 stores the heat medium flowing in the cold water pipeline 111. After the heat medium flowing in the cold water pipeline 111 is stored in the cold water tank 82, it is transported to the heat exchanger 81. In addition, after the heat medium cooled by the heat exchanger 81 returns to the cold water tank 82, it is transported to each module 11 through the cold water pipeline 111. Between the cold water tank 82 and the heat exchanger 81 on the cold water pipeline 111, a heat exchanger circulation water pump 821 is arranged. By driving the heat exchanger circulation water pump 821, the heat medium flowing in the cold water pipeline 111 circulates between the cold water tank 82 and the heat exchanger 81.

[0047] The cold water pipeline 111 branches and is respectively connected to the upstream side and the downstream side of each module 11, thereby connecting the cold water tank 82 with each module 11. In addition, between the cold water tank 82 and each module 11 on the cold water pipeline 111, a first cold water circulation water pump 822 and a second cold water circulation water pump 823 are arranged. In addition, on the cold water pipeline 111, a circulation pipeline 824 that returns from the downstream side of the second cold water circulation water pump 823 to the upstream side is arranged. A circulation valve 825 is arranged on the circulation pipeline 824.

[0048] The warm water tank 83 stores the heat medium flowing in the warm water pipeline 112. After the heat medium flowing in the warm water pipeline 112 is stored in the warm water tank 83, it is transported to the heat exchanger 81. In addition, after the heat medium heated by the heat exchanger 81 returns to the warm water tank 83, it is transported to each module 11 through the warm water pipeline 112. Between the warm water tank 83 and the heat exchanger 81 on the warm water pipeline 112, a heat exchanger circulation water pump 831 is arranged. By driving the heat exchanger circulation water pump 831, the heat medium flowing in the warm water pipeline 112 circulates between the warm water tank 83 and the heat exchanger 81.

[0049] The warm water pipeline 112 branches and is respectively connected to the upstream side and the downstream side of each module 11, thereby connecting the warm water tank 83 with each module 11. In addition, between the warm water tank 83 and each module 11 on the warm water pipeline 112, a first warm water circulation water pump 832 and a second warm water circulation water pump 833 are arranged. In addition, on the warm water pipeline 112, a circulation pipeline 834 that returns from the downstream side of the second warm water circulation water pump 833 to the upstream side is arranged. A circulation valve 835 is arranged on the circulation pipeline 834.

[0050] The three-way valve 30 is connected to the cold water pipeline 111, the warm water pipeline 112 and the module 11. The three-way valve 30 is respectively arranged on the upstream side and the downstream side of the module 11. The three-way valve 30 is configured to be able to switch between a cold water connection state in which the cold water pipeline 111 is connected to the module 11, a warm water connection state in which the warm water pipeline 112 is connected to the module 11, and a blocking state in which the connections of the cold water pipeline 111 and the warm water pipeline 112 to the module 11 are blocked.

[0051] The flow path switching of the three-way valve 30 is controlled by the control device 90. For the module 11, the heat medium is introduced through the three-way valve 30 arranged on the upstream side, and the heat medium returns to the heat exchanger 81 side through the three-way valve 30 arranged on the downstream side.

[0052] The bypass path 31 is a flow path that enables the heat medium to move between the modules 11. The bypass path 31 connects between two modules 11. The modules 11 connected by the bypass path 31 can be adjacent modules or non-adjacent modules 11 separated from each other. The detailed content of the connection structure of the bypass path 31 will be described below.

[0053] The bypass valve 32 is arranged on the bypass path 31. The bypass valves 32 are respectively arranged on a plurality of bypass paths 31. The opening and closing of the bypass valve 32 are controlled by the control device 90.

[0054] Next, the control device 90 will be described. The control device 90 controls the operation of each part of the carbon dioxide recovery device 1. The control device 90 controls operations such as driving or stopping the equipment used for carbon dioxide adsorption or desorption. The control device 90 performs the opening and closing control of the first valve 21, the second valve 22, the third valve 23, and the fourth valve 24 provided in each module 11, and the opening and closing control of each bypass valve 32. In addition, the control device 90 performs the drive control of the fan 61, the vacuum pump 62, the carbon dioxide recovery pump 63, the heat exchanger circulation water pump 821, the first cold water circulation water pump 822, the second cold water circulation water pump 823, the heat exchanger circulation water pump 831, the first warm water circulation water pump 832, the second warm water circulation water pump 833, etc., and the opening and closing control of the circulation valves 825 and 835.

[0055] The control device 90 is, for example, a computer having a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), etc. The control device 90 can be composed of one unit or multiple units.

[0056] <Recovery of Carbon Dioxide>

[0057] Next, the control for carbon dioxide recovery using the control device 90 will be described. The carbon dioxide recovery device 1 removes and recovers carbon dioxide from the air by alternately performing an adsorption process and a desorption process, compressing the desorbed carbon dioxide, and storing it in a tank (not shown). In the adsorption process, carbon dioxide in the sucked gas such as the atmosphere is adsorbed on the adsorbent 12 in the module 11. In the desorption process, the carbon dioxide adsorbed on the adsorbent 12 is desorbed. In the present embodiment, the adsorption process and the desorption process are performed with the time of the adsorption process: the time of the desorption process = 3:1.

[0058] The adsorption process is a process in which carbon dioxide is adsorbed 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 to generate a gas flow from upstream to downstream, and the gas containing carbon dioxide (for example, the atmosphere) is sucked through the third valve 23. The sucked gas passes through the adsorbent 12 in the module 11. At this time, the inside of the module 11 is at room 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, are discharged to the outside of the carbon dioxide recovery device 1 through the fourth valve 24 and the adsorption pipeline 101.

[0059] The desorption process is a process in which the carbon dioxide of the adsorbent 12 in the module 11 is desorbed. In the desorption process, the first valve 21, the third valve 23, and the fourth valve 24 of the module 11 are closed, and the second valve 22 is opened. The vacuum pump 62 operates to suck the inside of the module 11 and reduce the pressure to a vacuum state or a state close to a vacuum state. At the same time, by means of the heat exchange device 80, the heat medium as a heat source flows in the module 11 to supply heat energy, thereby raising the temperature of the adsorbent 12 in the module 11. The temperature increase control using the heat exchange device 80 will be described below.

[0060] By controlling the temperature increase of the adsorbent 12, the adsorbent 12 is also heated to a specific temperature (for example, 80°C) sufficient to perform the desorption process, and the carbon dioxide adsorbed on the adsorbent 12 is desorbed. 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 driven to store the desorbed carbon dioxide in a tank (not shown) through the carbon dioxide pipeline 103. In the present embodiment, the respective processes are controlled such that 12 of the 16 modules 11 perform the adsorption process and the remaining 4 modules perform the desorption process.

[0061] <Temperature increase control of the adsorbent>

[0062] The temperature increase control of the adsorbent 12 will be described. Figure 3 It is a schematic diagram showing the heat supply path in the first stage of the temperature increase of the adsorbent 12,Figure 4 is a schematic diagram showing the heat supply path in the second stage of the temperature rise of the adsorbent 12, Figure 5 is a schematic diagram showing the heat supply path in the third stage of the temperature rise of the adsorbent 12. Figure 6 is a diagram for explaining the heat transfer of the first module 11A and the second module 11B during the temperature rise of the adsorbent 12. In addition, in Figures 3 to 6 the illustration of the remaining modules 11 is omitted.

[0063] In the following description, the first module 11A and the second module 11B connected by the bypass path 31 among the plurality of modules 11 are taken as examples for explanation. In addition, regarding the common configuration that does not distinguish between the first module 11A and the second module 11B, the letter may sometimes be omitted and expressed as the module 11.

[0064] First, the structure for supplying the heat medium to the first module 11A and the second module 11B will be described. As Figures 3 to 5 shown, the first module 11A and the second module 11B each include an inlet-side flow path 33 connected to the inlet where the heat supply medium flows in, and an outlet-side flow path 34 connected to the outlet where the heat supply medium flows out.

[0065] The bypass path 31 is connected to the outlet-side flow path 34 of the first module 11A and is connected to the inlet-side flow path 33 of the second module 11B. In addition, a three-way valve 30 is arranged at the upstream end of the inlet-side flow path 33, and a three-way valve 30 is also arranged at the downstream end of the outlet-side flow path 34.

[0066] The three-way valve 30 arranged at the upstream end of the inlet-side flow path 33 of the first module 11A is designated as the inlet three-way valve 30a, and the three-way valve 30 arranged at the downstream end of the outlet-side flow path 34 is designated as the outlet three-way valve 30b. In addition, the three-way valve 30 arranged at the upstream end of the inlet-side flow path 33 of the second module 11B is designated as the inlet three-way valve 30c, and the three-way valve 30 arranged at the downstream end of the outlet-side flow path 34 is designated as the outlet three-way valve 30d.

[0067] The first stage of the temperature rise control will be described. As Figure 3 shown, in the first module 11A in the first stage, the desorption process is performed. In the first stage, the control device 90 controls the inlet three-way valve 30a to connect the hot water pipeline 112 to the inlet-side flow path 33, and controls the outlet three-way valve 30b to connect the outlet-side flow path 34 to the hot water pipeline 112. In addition, the control device 90 blocks the outlet-side flow path 34 of the first module 11A from the inlet-side flow path 33 of the second module 11B by controlling the bypass valve 32 arranged on the bypass path 31 to the closed state.

[0068] As Figure 6As shown, in the desorption process, the heat medium in the hot water pipeline 112 is introduced into the first module 11A, and the temperature of the adsorbent 12 in the first module 11A reaches 80°C. The flow rate of the heat medium reaching the first module 11A through the hot water pipeline 112 is throttled so that the temperature of the adsorbent 12 is maintained at 80°C. In addition, the temperature of the adsorbent 12 in the second module 11B is normal temperature below 30°C.

[0069] In the second module 11B of the first stage, the control device 90 controls the inlet three-way valve 30c and the outlet three-way valve 30d to block the second module 11B from both the cold water pipeline 111 and the hot water pipeline 112. In this state, the control device 90 controls the first valve 21, the third valve 23, and the fourth valve 24 of the module 11 to be in the closed state, and controls the second valve 22 to be in the open state to drive the vacuum pump 62. Thus, the operation of sucking and purging O2 inside the second module 11B by the vacuum pump 62 is performed.

[0070] An explanation is given for the second stage of the temperature rise control. As Figure 4 shown, in the first module 11A of the second stage, the desorption process ends and precooling starts. In the second stage, the control device 90 controls the inlet three-way valve 30a to connect the cold water pipeline 111 to the inlet side flow path 33, and controls the outlet three-way valve 30b to block the first module 11A from both the cold water pipeline 111 and the hot water pipeline 112. In addition, the control device 90 controls the bypass valve 32 to be in the open state to connect the outlet side flow path 34 of the first module 11A to the inlet side flow path 33 of the second module 11B.

[0071] As Figure 6 shown, the heat medium in the cold water pipeline 111 is introduced into the first module 11A, and the temperature of the adsorbent 12 in the first module 11A gradually cools from 80°C to 50°C. Since the outlet three-way valve 30b is closed, the heat medium flowing out from the first module 11A to the outlet side flow path 34 is introduced into the inlet side flow path 33 of the second module 11B through the bypass path 31. The heat medium passing through the bypass path 31 cools the adsorbent 12 when passing through the first module 11A, so it is heated by heat transfer and thus has a higher temperature than before being introduced into the first module 11A.

[0072] In the second module 11B of the second stage, the control device 90 controls the inlet three-way valve 30c to block the inlet side flow path 33 of the second module 11B from both the cold water pipeline 111 and the hot water pipeline 112, and controls the outlet three-way valve 30d to connect the outlet side flow path 34 of the second module 11B to the cold water pipeline 111.

[0073] As Figure 6As shown, the heated heat medium that has passed through the first module 11A is introduced into the second module 11B through the bypass path 31 and the inlet side flow path 33, and the temperature of the adsorbent 12 in the second module 11B gradually rises from room temperature to 50°C. Thus, in the second stage, heat is transferred from the first module 11A to the second module 11B.

[0074] The third stage of the temperature rise control will be described. As Figure 5 shown, in the first module 11A in the third stage, precooling continues. In the third stage, the control device 90 maintains the connection between the cold water pipeline 111 and the inlet side flow path 33 achieved by the inlet three-way valve 30a, and at the same time controls the outlet three-way valve 30b to connect the outlet side flow path 34 with the cold water pipeline 111. In addition, the control device 90 controls the bypass valve 32 to the closed state to close the outlet side flow path 34 of the first module 11A and the inlet side flow path 33 of the second module 11B.

[0075] As Figure 6 shown, the heat medium from the cold water pipeline 111 continues to be introduced into the first module 11A, and the temperature of the adsorbent 12 in the first module 11A gradually cools from 50°C to 30°C. The heat medium flowing out from the first module 11A to the outlet side flow path 34 returns to the cold water pipeline 111 through the outlet three-way valve 30b.

[0076] In the second module 11B in the third stage, the control device 90 controls the inlet three-way valve 30c to connect the inlet side flow path 33 with the warm water pipeline 112, and controls the outlet three-way valve 30d to connect the outlet side flow path 34 with the warm water pipeline 112.

[0077] As Figure 6 shown, the 80°C heat medium in the warm water pipeline 112 is introduced into the second module 11B, and the temperature of the adsorbent 12 in the second module 11B gradually rises from 50°C to 80°C.

[0078] Here, with reference to Figure 7 the differences between the carbon dioxide recovery device 1 of the present embodiment and the carbon dioxide recovery device of the prior art will be described. Figure 7 is a diagram for explaining the heat transfer in the first module and the second module during the temperature rise of the adsorbent when there is no bypass path 31 in the prior art.

[0079] As Figure 7 shown, when at Figures 3 to 5When the bypass path 31 is omitted from the configuration, heat transfer from the first module 11A to the second module 11B does not occur. Therefore, the temperature increase control is performed independently in the first module 11A and the second module 11B. During cooling, the heat medium that has received heat from the first module 11A returns to the cold water tank 82 via the cold water pipeline 111 and is not utilized in the second module 11B. Therefore, the heat received during cooling is also averaged in the cold water tank 82. Therefore, it is necessary to supply warm water to the adsorbent 12 of the second module from the normal temperature stage. In this regard, according to the configuration of the present embodiment, the adsorbent 12 of the second module 11B is pre-heated in the second stage. Therefore, it is only necessary to increase the temperature from 50°C to 80°C in the third stage, and thus the supply amount of warm water can be made smaller than when there is no bypass path 31.

[0080] Next, Figure 8 the switching timing of the supply path of the heat medium during the temperature increase control will be described. Figure 8 FIG. is a flowchart showing an example of the processing flow of the temperature increase control performed by the carbon dioxide recovery device of the present embodiment.

[0081] In step S1, the control device 90 determines whether the temperature difference ΔT between the adsorbent 12 of the first module 11A and the adsorbent 12 of the second module 11B is equal to or greater than a certain value. In the present embodiment, the control device 90 obtains the measurement information of the temperature sensor 27 of the first module 11A and obtains the measurement information of the temperature sensor 27 of the second module 11B to calculate the temperature difference. The control device 90 determines whether the calculated temperature difference is equal to or greater than a preset temperature difference ΔT.

[0082] When the temperature difference ΔT between the adsorbent 12 of the first module 11A and the adsorbent 12 of the second module 11B is equal to or greater than a certain value, the control device 90 advances the process to step S2 (step S1, yes). When the temperature difference ΔT between the adsorbent 12 of the first module 11A and the adsorbent 12 of the second module 11B is less than a certain value, the control device 90 advances the process to step S5 (step S1, no).

[0083] In addition, the processing from step S2 to step S4 corresponds to Figure 4 the second stage shown in, and the processing from step S5 to step S7 corresponds to Figure 5 the third stage shown in.

[0084] In step S2, the control device 90 controls the inlet three-way valve 30a of the first module 11A to connect the cold water pipeline 111 to the inlet side flow path 33, and controls the outlet three-way valve 30b to block the first module 11A from both the cold water pipeline 111 and the warm water pipeline 112.

[0085] In step S3, the control device 90 controls the inlet three-way valve 30c to block the inlet-side flow path 33 of the second module 11B from both the cold water pipeline 111 and the warm water pipeline 112, and controls the outlet three-way valve 30d to connect the outlet-side flow path 34 of the second module 11B to the cold water pipeline 111.

[0086] In step S4, the control device 90 controls the bypass valve 32 to an open state to connect the outlet-side flow path 34 of the first module 11A to the inlet-side flow path 33 of the second module 11B. After the processing in step S4, the process returns to step S1, and steps S1 and subsequent steps are executed.

[0087] When the temperature difference is less than ΔT, in step S5, the control device 90 controls the bypass valve 32 to a closed state to block the outlet-side flow path 34 of the first module 11A from the inlet-side flow path 33 of the second module 11B.

[0088] In step S6, the control device 90 controls the inlet three-way valve 30a to connect the inlet-side flow path 33 of the first module 11A to the cold water pipeline 111, and controls the outlet three-way valve 30b to connect the outlet-side flow path 34 of the first module 11A to the cold water pipeline 111.

[0089] In step S7, the control device 90 controls the inlet three-way valve 30c to connect the inlet-side flow path 33 of the second module 11B to the warm water pipeline 112, and controls the outlet three-way valve 30d to connect the outlet-side flow path 34 of the second module 11B to the warm water pipeline 112. Thus, the temperature increase control of the second module 11B ends, and the process transfers to the desorption process.

[0090] In addition, for ease of explanation, Figure 8 the flowcharts for steps S2, S3, and S4 are separately described, but steps S2, S3, and S4 can also be performed simultaneously. The same applies to steps S5, S6, and S7. Thus, Figure 8 the flowcharts are for example purposes, and the order and content of the processing can be appropriately changed.

[0091] The heat transfer described above occurs between the modules 11 connected via the bypass path 31. Figure 9 is a schematic diagram showing the relationship between the cycles of the adsorption process and the desorption process and the heat transfer between the multiple modules 11. As Figure 9 shown, in each module 11, a cycle of desorption, precooling, adsorption, O2 purge, and temperature increase is executed.

[0092] The first module 11A and the second module 11B are connected by a bypass path 31. The second module 11B and the third module 11C are also connected by a different bypass path 31. The third module 11C and the fourth module 11D are also connected by a different bypass path 31. Further, the fourth module 11D and the first module 11A are also connected by a different bypass path 31. In the present embodiment, four modules 11, namely the first module 11A, the second module 11B, the third module 11C, and the fourth module 11D, form a group, and a loop for heat transfer is constituted by this group.

[0093] If the first module 11A enters a heating cycle and the second module 11B enters a precooling cycle, heat moves from the second module 11B in the precooling process to the first module 11A in the heating process. If the second module 11B enters a heating cycle and the third module 11C enters a precooling cycle, heat moves from the third module 11C in the precooling process to the second module 11B in the heating process. If the third module 11C enters a heating cycle and the fourth module 11D enters a precooling cycle, heat moves from the fourth module 11D in the precooling process to the third module 11C in the heating process. If the fourth module 11D enters a heating cycle and the first module 11A enters a precooling cycle, heat moves from the first module 11A in the precooling process to the fourth module 11D in the heating process. In the present embodiment, such heat transfer is performed separately in 16 modules 11.

[0094] Figure 10 It is a schematic diagram showing the numbers assigned to the modules 11 of the carbon dioxide recovery device 1 according to the present embodiment. In Figure 10 , the numbers are shown by # and digits to distinguish the modules 11. In Figure 10 the example shown, the modules 11 of #1, the modules 11 of #5, the modules 11 of #9, and the modules 11 of #13 are the first group. The modules 11 of #2, the modules 11 of #6, the modules 11 of #10, and the modules 11 of #14 are the second group. The modules 11 of #3, the modules 11 of #7, the modules 11 of #11, and the modules 11 of #15 are the third group. The modules 11 of #4, the modules 11 of #8, the modules 11 of #12, and the modules 11 of #16 are the fourth group. The first group, the second group, the third group, and the fourth group are all four modules 11 connected in series by bypass paths 31 as Figure 9 shown. Heat transfer between the modules 11 is performed in units of a group.

[0095] In addition, in the present embodiment, the respective processes for performing the adsorption process and the desorption process are staggered among the plurality of modules 11 so as not to be performed in the same time sequence. Thus, it is possible to effectively avoid the situation where the output instantaneously increases due to the simultaneous operation of the equipment (the fan 61, the heat exchange device 80, the vacuum pump 62, and the carbon dioxide recovery pump 63). In addition, the time calculated by dividing the sum of the adsorption time and the desorption time by the number M of the modules 11 is set as the time difference of the operation time sequence between the modules 11. Thus, it is possible to make the operation time or output of each piece of equipment during the operation time more uniform, and it is possible to make the operation for realizing each process of the adsorption process or the desorption process more fixed, thereby improving the energy efficiency. Further, from the viewpoint of equalizing the load, the number of the modules 11 is preferably 10 or more.

[0096] <Method for setting the number of modules and a set>

[0097] In the present embodiment, the number of the modules 11 constituting a set is set in a manner corresponding to the following mathematical formula (1). In the mathematical formula (1), M represents the number of the modules 11 constituting a set, N represents a natural number, and R represents the ratio of the adsorption time to the desorption time (adsorption time / desorption time):

[0098] M = N×(R + 1) Mathematical formula (1).

[0099] Here, the adsorption time: desorption time = 3:1. At this time, the ratio of the adsorption time to the desorption time (adsorption time / desorption time) R is 3. Therefore, the appropriate number of the modules 11 is 4 (N = 1), 8 (N = 2), 12 (N = 3), 16 (N = 4).... The number of the modules constituting the group connecting the bypass path 31 is set according to the appropriate number of the modules 11 based on the mathematical formula (1). When R is 3, the modules 11 are grouped in sets of 4. When the total number of the modules 11 is 8, there are two groups, and when the total number of the modules 11 is 12, there are three groups. When the total number of the modules 11 is 16, there are four groups as in the above-described embodiment.

[0100] In addition, according to the mathematical formula (1), M may be a value with a decimal point, but in practice, the value of N is set in such a way that the set number of the modules is a natural number. For example, when R = 2.5, the natural numbers are even numbers such as 2, 4, 6..., and the appropriate number of the modules 11 is 7 (N = 2), 14 (N = 4), 21 (N = 6). In addition, when R = 3.5, the natural numbers are even numbers such as 2, 4, 6..., and the appropriate number of the modules 11 is 9 (N = 2), 18 (N = 4), 27 (N = 6). That is, N is set in such a way that the number of the modules 11 is a natural number. Thus, there are multiple optimal numbers of the modules 11 selected according to the ratio R of the adsorption / desorption time.

[0101] Figure 11 is a diagram showing heat transfer between 16 modules of the present embodiment. In Figure 11 , heat transfer in the adsorption process and desorption process for the numbering of module 11 is shown. The vertical axis is the ratio of heat transfer. As Figure 11 shown, the number of module 11 is set based on mathematical formula (1), and the number of a set of module 11 is set to an appropriate number of the minimum module 11 based on mathematical formula (1), whereby the minimum amount of thermal energy required for the entire carbon dioxide recovery device 1 can be achieved.

[0102] As described above, the carbon dioxide recovery device 1 of the present embodiment includes: a plurality of modules 11 having an adsorbent 12 therein, the plurality of modules 11 performing an adsorption process and a desorption process, the adsorption process being to attract a gas containing carbon dioxide to the adsorbent 12 to adsorb carbon dioxide, and the desorption process being to desorb carbon dioxide from the adsorbent 12 by heating the periphery of the adsorbent 12 under a reduced pressure state; a heat exchange device 80 that supplies heat for heating the adsorbent 12 to each of the plurality of modules 11 via a heat medium; and a bypass path 31 that connects a first module 11A, which is one of the plurality of modules 11, and a second module 11B different from the first module 11A and through which the heat medium can flow.

[0103] Thereby, waste heat recovery can be performed between the first module 11A and the second module 11B. Efficient heat transfer can be performed between the first module 11A and the second module 11B, thereby reducing the electric energy required to heat a heat medium such as warm water.

[0104] In addition, in the present embodiment, the heat medium after cooling the first module 11A after the desorption process is supplied to the second module 11B to be heated in the desorption process via the bypass path 31, thereby performing heat supply from the first module 11A to the second module 11B. Thereby, the heat received by the heat medium during cooling of the first module 11A can be directly transferred to the second module 11B without passing through the cold water pipeline 111, thereby further improving the energy efficiency.

[0105] In addition, the carbon dioxide recovery device 1 of the present embodiment further includes a warm water tank 83 that is disposed between the heat exchange device 80 and the module 11 and stores warm water as the heat medium. Thereby, by the two heat supplies of heat supply from the first module 11A to the second module 11B through the bypass path 31 and heat supply using the warm water from the warm water tank 83, the adsorbent 12 to be heated can be efficiently and surely heated.

[0106] In addition, in the present embodiment, the adsorbent 12 is heated by two-stage heating. The two-stage heating is to supply heat from the first module 11A to the second module 11B via the bypass path 31 to heat the adsorbent 12, and then supply heat from the warm water tank 83 to the second module 11B to heat the adsorbent 12. Thus, the second module 11B can be preheated using the heat of the first module 11A. Therefore, the amount of warm water required to raise the temperature of the adsorbent 12 in the second module 11B to a specific temperature (e.g., 80°C) can be reduced, and the energy cost can be further reduced.

[0107] In addition, in the present embodiment, when the temperature difference between the adsorbent 12 in the first module 11A and the adsorbent 12 in the second module 11B, which is the object to be heated during the desorption process, during the cooling process after the desorption process is equal to or greater than a certain value, heat is supplied from the first module 11A to the second module 11B via the bypass path 31. If the temperature difference between the adsorbent 12 in the first module 11A and the adsorbent 12 in the second module 11B, which is the object to be heated, during the cooling process is lower than the certain value, the bypass path 31 is closed, and heat supply from the warm water tank 83 is started. However, if the temperature difference between the first module 11A and the second module 11B is eliminated, substantially no heat transfer occurs from the first module 11A to the second module 11B. Therefore, it is preferable to quickly switch the heat supply from the warm water tank 83. In this regard, according to the configuration of the present embodiment, the switching from the heat supply from the first module 11A to the second module 11B to the heat supply from the warm water tank 83 is automatically performed at an appropriate timing. It is possible to avoid a situation where the time required to complete the desorption process becomes longer due to a timing delay in switching to the heat supply from the warm water tank 83, and thus more efficient carbon dioxide recovery can be achieved.

[0108] In addition, in the present embodiment, the carbon dioxide recovery device 1 further includes: a fan 61 that supplies gas to the inside of the module 11; a heat exchange device 80 as a heat source that performs heat supply for heating the adsorbent 12 of the module 11; and a vacuum pump 62 and a carbon dioxide recovery pump 63 that suck the gas inside the module 11. And at least one of the fan 61, the heat exchange device 80, the vacuum pump 62, and the carbon dioxide recovery pump 63 is shared by the plurality of modules 11. If a natural number is set as N and the ratio obtained by dividing the adsorption time of the adsorbent 12 by the desorption time is set as R, the number M of the modules 11 connected in series by the bypass path 31 is set based on the following mathematical formula (1):

[0109] M = N×(R + 1) Mathematical formula (1).

[0110] Accordingly, by setting the number of modules 11 corresponding to the time ratios of adsorption and desorption of the adsorbent 12, respectively, and the operation schedule of each module 11, the operations of the adsorption process and the desorption process in each module 11 are continuous, thereby enabling suppression of energy consumption. Since energy consumption can be suppressed, it is possible to select devices (fan 61, heat exchange device 80, vacuum pump 62, and carbon dioxide recovery pump 63) with smaller output or capacity, thereby enabling reduction of the operation cost and the manufacturing cost.

[0111] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments or modified examples. In addition, the effects described in the above embodiments are merely exemplary effects and are not limited to the content described in the above embodiments.

[0112] Reference Numerals

[0113] 1 Carbon dioxide recovery device

[0114] 11 Module

[0115] 11A First module

[0116] 11B Second module

[0117] 12 Adsorbent

[0118] 30 Three-way valve

[0119] 31 Bypass path

[0120] 32 Bypass valve

[0121] 61 Fan

[0122] 62 Vacuum pump

[0123] 63 Carbon dioxide recovery pump

[0124] 80 Heat exchange device

[0125] 81 Heat exchanger

[0126] 82 Cold water tank

[0127] 83 Warm water tank

Claims

1. A carbon dioxide recovery device, comprising: a plurality of modules, which have an adsorbent material inside and perform an adsorption process and a desorption process. The adsorption process is to attract a gas containing carbon dioxide to the adsorbent material to adsorb the carbon dioxide, and the desorption process is to desorb the carbon dioxide from the adsorbent material by heating the periphery of the adsorbent material under a reduced pressure state; a heat exchange device that supplies heat for heating the adsorbent material to each of the plurality of modules via a heat medium; and a bypass path that connects a first module, which is one of the plurality of modules, and a second module different from the first module and allows the heat medium to flow through.

2. The carbon dioxide recovery device according to claim 1, wherein the heat medium after cooling the first module after the desorption process is supplied to the second module to be heated in the desorption process via the bypass path, thereby performing heat supply from the first module to the second module.

3. The carbon dioxide recovery device according to claim 1 or 2, wherein the carbon dioxide recovery device further includes a warm water tank, which is arranged between the heat exchange device and the module and stores warm water as the heat medium.

4. The carbon dioxide recovery device according to claim 3, wherein the temperature rise of the adsorbent material is performed by two-stage heating. The two-stage heating is to supply heat to the second module from the first module via the bypass path to heat the adsorbent material, and then supply heat to the second module from the warm water tank to heat the adsorbent material.

5. The carbon dioxide recovery device according to claim 4, wherein when the temperature difference between the adsorbent material of the first module during the cooling process after the desorption process and the adsorbent material of the second module to be heated in the desorption process is a certain value or more, heat supply from the first module to the second module is performed via the bypass path, if the temperature difference between the adsorbent material of the first module during the cooling process and the adsorbent material of the second module to be heated is lower than a certain value, the bypass path is closed and heat supply from the warm water tank is started.

6. The carbon dioxide recovery device according to claim 1 or 2, wherein the carbon dioxide recovery device further includes: a fan that supplies gas to the inside of the module; a heat source that performs heat supply for heating the adsorbent material of the module; and a vacuum pump that sucks the gas inside the module; and at least one of the fan, the heat source, and the vacuum pump is shared by the plurality of modules, if a natural number is set as N and the ratio obtained by dividing the adsorption time of the adsorbent material by the desorption time is set as R, the number M of the modules connected in series by the bypass path is set based on the following mathematical formula (1): M = N × (R + 1) Mathematical formula (1).

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