Carbon dioxide recovery system and operation method of the same

Abstract

To provide a carbon dioxide recovery system which achieves space saving and an operation method of the same.SOLUTION: A carbon dioxide recovery system includes: a carbon dioxide recovery device having a carbon dioxide recovery device body including an absorption tower for absorbing carbon dioxide in a process fluid, a generation tower for heating the process fluid and separating the carbon dioxide from the process fluid, and thereby regenerating the process fluid, and a circulation line for circulating the process fluid between the absorption tower and the regeneration tower, and a tank connected to the carbon dioxide recovery device body; a steam generator for heating which generates steam for heating; a process fluid heater for heat exchanging the steam for heating with the process fluid of the regeneration tower; and a tank storage line for supplying steam condensed water from the process fluid heater, to the tank of the carbon dioxide recovery device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a carbon dioxide capture system and a method for operating the same. [Background technology]

[0002] Carbon dioxide capture systems that capture carbon dioxide contained in gases such as exhaust gases are known. Some of these carbon dioxide capture systems include a regeneration tower that heats an absorption liquid that has absorbed carbon dioxide to separate the carbon dioxide and regenerate the absorption liquid. In some cases, a reboiler is connected to the regeneration tower to heat the absorption liquid. As a heat source for the reboiler, a portion of the heating steam generated in another adjacent facility may be used. The steam that has been heat exchanged by the reboiler is cooled and turned into steam condensate, which is returned to the other adjacent facility. However, in the reboiler, if the absorption liquid leaks, it may be mixed into the steam condensate. If the absorption liquid is mixed into the steam condensate, it may affect the facility that supplies the heating steam. For this reason, in the carbon dioxide capture system as described above, the presence or absence of the absorption liquid being mixed into the steam condensate is detected.

[0003] Patent Document 1 describes a technology for detecting leakage of an absorbing liquid component into steam condensate discharged from a reboiler in a carbon dioxide recovery system that recovers carbon dioxide from exhaust gas. The carbon dioxide recovery system in Patent Document 1 includes an upstream line that supplies heated steam to the reboiler and a downstream line that discharges steam condensate from the reboiler, and accurately monitors and detects leakage of the absorbing liquid component by measuring the physical quantity of the absorbing liquid component in the steam condensate obtained by cooling and condensing the heated steam in the upstream line, and by measuring the physical quantity of the absorbing liquid component in the steam condensate discharged from the reboiler. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6913604 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in a carbon dioxide capture system such as that of Patent Document 1, when carbon dioxide capture is started, a precise water quality test of the steam condensate may be requested by the equipment side that supplies the heating steam. Such a water quality test needs to be performed at a separate location by extracting the steam condensate discharged from the reboiler. It takes a certain amount of time to complete this water quality test, and the water quality of the steam condensate discharged from the reboiler during that time is not guaranteed. Therefore, the steam condensate discharged from the reboiler cannot be returned to the equipment side that supplies the heating steam, and the steam condensate needs to be stored in a tank or the like at least until the water quality test is completed. However, due to the constraints of site space, etc., it may be difficult to install a tank for storing such steam condensate.

[0006] The present disclosure has been made in consideration of the above circumstances, and provides a carbon dioxide capture system and an operating method thereof that are capable of saving space. [Means for solving the problem]

[0007] In order to solve the above problems, the following configuration is adopted. A carbon dioxide capture system according to one aspect of the present disclosure comprises a carbon dioxide capture apparatus having a carbon dioxide capture apparatus main body including an absorption tower that absorbs carbon dioxide contained in a carbon dioxide-containing gas into a process fluid, a regeneration tower that heats the process fluid to separate carbon dioxide from the process fluid to regenerate the process fluid, and a circulation line that circulates the process fluid between the absorption tower and the regeneration tower, a carbon dioxide capture apparatus having a tank connected to the carbon dioxide capture apparatus main body, a heating steam generator that generates heating steam, a process fluid heater having a reboiler that exchanges heat between the heating steam and the process fluid in the regeneration tower, and a tank storage line that supplies steam condensate from the reboiler to the tank of the carbon dioxide capture apparatus.

[0008] A method for operating a carbon dioxide capture system according to one aspect of the present disclosure includes a carbon dioxide capture apparatus including: an absorption tower for absorbing carbon dioxide contained in a carbon dioxide-containing gas into a process fluid; a regeneration tower for heating the process fluid to separate carbon dioxide from the process fluid to regenerate the process fluid; and a circulation line for circulating the process fluid between the absorption tower and the regeneration tower; and a tank connected to the carbon dioxide capture apparatus main body; a heating steam generator for generating heating steam; and a reboiler for exchanging heat between the heating steam and the process fluid in the regeneration tower. and a process fluid heater having a reboiler, the method including: a tank supplying step of supplying steam condensate discharged from the reboiler to the tank of the carbon dioxide capture apparatus when the carbon dioxide capture apparatus main body is started; an inspection step of inspecting, in parallel with the tank supplying step, whether the process fluid has been mixed into the steam condensate discharged from the reboiler; and a switching step of switching the supply destination of the steam condensate discharged from the reboiler from the tank of the carbon dioxide capture apparatus to the heating steam generator when it is determined by the inspection step that there is no mixing of the process fluid. Effect of the Invention

[0009] According to the present disclosure, space can be saved. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a carbon dioxide capture system in a first embodiment of the present disclosure. [Diagram 2] 3 is a flowchart showing an operation method of the carbon dioxide capture system in the first embodiment of the present disclosure. [Diagram 3] FIG. 11 is a diagram showing a schematic configuration of a carbon dioxide capture system in a second embodiment of the present disclosure. [Figure 4] 10 is a flowchart showing an operation method of the carbon dioxide capture system in the second embodiment of the present disclosure. [Diagram 5] FIG. 1 is a diagram showing a schematic configuration of a carbon dioxide capture system according to a first modified example of an embodiment of the present disclosure. [Figure 6] FIG. 13 is a diagram showing a schematic configuration of a carbon dioxide capture system according to a second modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, a carbon dioxide capture system and an operating method thereof according to an embodiment of the present disclosure will be described with reference to the drawings. First embodiment The carbon dioxide capture system in this embodiment captures carbon dioxide from a carbon dioxide-containing gas that contains carbon dioxide. Examples of the carbon dioxide-containing gas include exhaust gas from a device that combusts fuel, such as a gas turbine, an internal combustion engine, and a boiler.

[0012] FIG. 1 is a diagram showing a schematic configuration of a carbon dioxide capture system in the first embodiment of the present disclosure. As shown in FIG. 1, a carbon dioxide capture system 100 in the first embodiment includes a carbon dioxide capture device 110, a heating steam generator 120, a process fluid heater 130, a tank storage line 140, and a control device 150.

[0013] (Carbon dioxide capture equipment) The carbon dioxide capture device 110 includes a carbon dioxide capture device main body 111 and a tank 112 .

[0014] (Carbon dioxide capture device body) The carbon dioxide capture device main body 111 includes at least an absorption tower 11, a regeneration tower 12, and a circulation line 13. The carbon dioxide capture device main body 111 illustrated in this embodiment includes a cooling tower 14 and a carbon dioxide-containing gas supply line 15 in addition to the absorption tower 11, the regeneration tower 12, and the circulation line 13. The cooling tower 14 lowers the temperature of the carbon dioxide-containing gas G by contacting the carbon dioxide-containing gas G with cooling water. The cooling tower 14 also uses an alkaline chemical such as an aqueous solution of caustic soda to remove sulfur oxides contained in the carbon dioxide-containing gas G. The carbon dioxide-containing gas supply line 15 supplies the carbon dioxide-containing gas G, which has been cooled by the cooling tower 14 and from which sulfur oxides have been removed, to the absorption tower 11.

[0015] The absorption tower 11 generates a rich liquid R by contacting the carbon dioxide-containing gas G containing carbon dioxide with an absorbing liquid (process fluid). The absorbing liquid is capable of absorbing carbon dioxide by contacting with the carbon dioxide-containing gas G, and the rich liquid R is an absorbing liquid in a state in which carbon dioxide has been absorbed from the carbon dioxide-containing gas G. The carbon dioxide-containing gas G is introduced into the absorption tower 11 using a blower (not shown) or the like. An example of the absorbing liquid is an amine-based absorbing liquid that absorbs carbon dioxide by a chemical absorption method. An example of the amine-based absorbing liquid is MEA (monoethanolamine).

[0016] The carbon dioxide-containing gas G introduced into the absorption tower 11 comes into contact with the absorbing liquid (lean liquid Le) sprayed from the top of the absorption tower 11 by a nozzle or the like. As a result, the carbon dioxide in the carbon dioxide-containing gas G is absorbed by the absorbing liquid (lean liquid Le), and the absorbing liquid becomes a rich liquid R. The remaining treated gas Gp from which the carbon dioxide has been absorbed by the absorbing liquid is discharged from the top of the absorption tower 11. In the absorption tower 11 of this embodiment, before discharging the treated gas Gp to the outside, an acidic chemical such as sulfuric acid is used to remove the absorbing liquid contained in the treated gas Gp. The treated gas Gp discharged from the absorption tower 11 may be washed with washing water to remove the absorbing liquid and the like.

[0017] The regenerator 12 generates a lean liquid Le, which is an absorbing liquid capable of absorbing carbon dioxide. Specifically, the regenerator 12 generates the lean liquid Le by heating the rich liquid R to release carbon dioxide from the rich liquid R. A process fluid heater 130 for heating the rich liquid R is connected to the regenerator 12 of this embodiment. Carbon dioxide gas (CO2) released from the rich liquid R is discharged from the upper part of the regenerator 12.

[0018] The circulation line 13 circulates the absorption liquid between the absorption tower 11 and the regeneration tower 12. The circulation line 13 includes a rich liquid line 16 and a lean liquid line 17. The rich liquid line 16 guides the rich liquid R from the absorption tower 11 to the regeneration tower 12. The lean liquid line 17 guides the lean liquid Le from the regeneration tower 12 to the absorption tower 11.

[0019] (tank) The tank 112 is connected to the carbon dioxide capture apparatus main body 111. In this embodiment, the tank 112 includes one process fluid tank 112A and two chemical tanks 112B and 112C.

[0020] The process fluid tank 112A is capable of storing the absorbing liquid used in the carbon dioxide capture device main body 111. The process fluid tank 112A in this embodiment is connected to both the absorption tower 11 and the regeneration tower 12 via a process fluid evacuation line 19. The process fluid tank 112A is capable of evacuating the absorbing liquid stored in the absorption tower 11 and the regeneration tower 12 during maintenance of the absorption tower 11 and the regeneration tower 12, for example, and storing wastewater containing an absorbing liquid component generated during cleaning of the absorption tower 11 and the regeneration tower 12. The use of the process fluid tank 112A is not limited to the above use, and may be used, for example, as a reservoir tank for the absorbing liquid used in the absorption tower 11 and the regeneration tower 12.

[0021] The chemical tanks 112B and 112C store chemicals used in the carbon dioxide capture apparatus main body 111. The chemical tank 112B is connected to the cooling tower 14 via a first chemical supply line 20. The chemical tank 112B stores an alkaline chemical, such as an aqueous solution of caustic soda, used in the cooling tower 14. The alkaline chemical stored in the chemical tank 112B is supplied to the cooling tower 14 via the first chemical supply line 20. The chemical tank 112C is connected to the absorption tower 11 via a second chemical supply line 21. The chemical tank 112C stores an acidic chemical, such as sulfuric acid, used in the absorption tower 11. The acidic chemical stored in the chemical tank 112C is supplied to the absorption tower 11 via the second chemical supply line 21.

[0022] (Steam generator for heating) The heating steam generator 120 generates heating steam. An example of the heating steam generator 120 is a device that generates steam using exhaust heat from a facility that discharges a carbon dioxide-containing gas G. A part or all of the heating steam generated by the heating steam generator 120 is supplied to the process fluid heater 130.

[0023] (Process Fluid Heater) The process fluid heater 130 heats the rich liquid R by exchanging heat between the rich liquid R, which is a process fluid, and the heating steam, which is a heat medium. The process fluid heater 130 of this embodiment includes a heating steam line 23, a reboiler 24, and a steam condensate line 25. The heating steam line 23 supplies the heating steam generated by the heating steam generator 120 to the reboiler 24. The reboiler 24 exchanges heat between the heating steam supplied by the heating steam line 23 and the rich liquid R as a process fluid. The steam condensate line 25 returns the steam condensate condensed by heat exchange with the rich liquid R to the heating steam generator 120. The heating steam line 23 includes a first control valve 28 that opens and closes a flow path through which the heating steam flows. The steam condensate line 25 includes a second control valve 29 that opens and closes a flow path through which the steam condensate flows. The first control valve 28 and the second control valve 29 can be opened and closed by a control signal output from a control device 150 (described later).

[0024] (Tank storage line) The tank storage line 140 supplies the steam condensate from the process fluid heater 130 to the tank 112 of the carbon dioxide capture device 110. The tank storage line 140 illustrated in this embodiment is capable of supplying the steam condensate from the process fluid heater 130 to the process fluid tank 112A. The tank storage line 140 in this embodiment is branched and connected to the steam condensate line 25. More specifically, the tank storage line 140 in this embodiment connects the steam condensate line 25 closer to the process fluid heater 130 than the second control valve 29 to the process fluid tank 112A. The tank storage line 140 includes a third control valve 31 that opens and closes a flow path through which the steam condensate flows. The third control valve 31 can be opened and closed by a control signal output from a control device 150 (described later).

[0025] (Control device) The control device 150 controls the operation of the first control valve 28, the second control valve 29, and the third control valve 31. More specifically, the control device 150 switches between a state in which the steam condensate from the process fluid heater 130 is returned to the heating steam generator 120 via the steam condensate line 25 and a state in which the steam condensate from the process fluid heater 130 is introduced into the process fluid tank 112A via the tank storage line 140, based on an operation input by an operator or the like. The first control valve 28 in this embodiment is closed when it is necessary to stop the supply of the heating steam, and is open otherwise. The control device 150 can be exemplified by a so-called computer device including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage, and a signal transmission / reception module. The control device 150 realizes a functional configuration in which the supply destination of the steam condensate is switched between the heating steam generator 120 and the tank 112 by executing a program stored in advance in a storage device such as a ROM or a storage by the CPU.

[0026] (How to drive) Next, a method of operating the carbon dioxide capture system 100 having the above-mentioned configuration will be described with reference to the drawings. FIG. 2 is a flowchart showing a method for operating the carbon dioxide capture system in the first embodiment of the present disclosure. As shown in FIG. 2, the method of operating the carbon dioxide capture system 100 in the first embodiment includes a tank supply step S10, an inspection step S20, and a switching step S30.

[0027] In the tank supply step S10, when the carbon dioxide capture apparatus main body 111 is started, the steam condensed water coming out of the process fluid heater 130 is supplied to the tank 112 of the carbon dioxide capture apparatus 110. In the tank supply step S10 of this embodiment, the steam condensed water coming out of the process fluid heater 130 is supplied to the process fluid tank 112A of the carbon dioxide capture apparatus 110. At this time, the first control valve 28 is controlled to be in an open state, the second control valve 29 is controlled to be in a closed state, and the third control valve 31 is controlled to be in an open state. Note that before the carbon dioxide capture apparatus main body 111 is started, the first control valve 28 is controlled to be in a closed state so that heating steam is not supplied to the process fluid heater 130.

[0028] In this tank supply step S10, the absorbing liquid stored in the process fluid tank 112A is diluted by the steam condensate water of which the water quality is not guaranteed, which comes out of the process fluid heater 130. When the absorbing liquid is an absorbing liquid containing water such as an amine solution, the carbon dioxide capture device main body 111 is capable of adjusting the concentration by evaporating the water contained in the absorbing liquid. Therefore, the absorbing liquid diluted with the steam condensate water in the process fluid tank 112A can be returned to the carbon dioxide capture device main body 111 and used as the absorbing liquid. Also, even if the absorbing liquid is not stored in the process fluid tank 112A, the steam condensate water of which the water quality is not guaranteed, which comes out of the process fluid heater 130, may be temporarily stored in an empty process fluid tank 112A, and returned to the carbon dioxide capture device main body 111 for evaporation after the switching step S30 described later.

[0029] In the inspection process S20, in parallel with the tank supply process S10, the steam condensate discharged from the process fluid heater 130 is inspected for contamination with the absorbing liquid. The steam condensate for inspection can be collected, for example, via a sampling pipe (not shown). The inspection in this embodiment is a precise water quality inspection, and is carried out by bringing the water to an inspection location (for example, a lab, etc.) separate from the carbon dioxide capture system 100.

[0030] In the switching process S30, when it is determined by the inspection process S20 that the steam condensate is not mixed with the process fluid, the supply destination of the steam condensate discharged from the process fluid heater 130 is switched from the tank 112 (process fluid tank 112A) of the carbon dioxide capture device 110 to the heating steam generator 120. For this, the first control valve 28 is opened, the second control valve 29 is opened, and the third control valve 31 is closed. As a result, the carbon dioxide capture system 100 transitions from an operating state at start-up to an operating state during normal operation. Note that when the carbon dioxide capture system 100 is stopped, for example, the first control valve 28 may be closed, the second control valve 29 may be closed, and the third control valve 31 may be open.

[0031] (Action and effect) According to the above-described first embodiment, when starting up the carbon dioxide capture apparatus main body 111, the steam condensed water coming out of the process fluid heater 130 can be supplied to the process fluid tank 112A by the tank storage line 140 without being returned to the heating steam generator 120. Furthermore, since the steam condensed water is supplied to the process fluid tank 112A used by the carbon dioxide capture apparatus 110 until it is confirmed that there is no problem with the steam condensed water when starting up the carbon dioxide capture apparatus main body 111, it is possible to prevent the steam condensed water from being returned to the heating steam generator 120 without providing a dedicated tank for temporarily storing the steam condensed water. Therefore, it is possible to suppress an increase in the number of tanks and achieve space saving.

[0032] In the first embodiment, the system further includes a third control valve 31 provided in the tank storage line 140, a second control valve 29 provided in the steam condensate line 25 closer to the heating steam generator 120 than the tank storage line 140, and a control device 150 that controls the second control valve 29 and the third control valve 31. This makes it possible to automatically switch the supply destination of the steam condensate, thereby reducing the burden on the operator. In addition, even if the second control valve 29 and the third control valve 31 are disposed far away from each other, they can be quickly opened and closed.

[0033] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to the drawings. In this second embodiment, a water quality monitoring device is provided in the steam condensate line in addition to the first embodiment described above. Therefore, the same parts as those in the first embodiment described above are denoted by the same reference numerals and will not be described again.

[0034] FIG. 3 is a diagram showing a schematic configuration of a carbon dioxide capture system in the second embodiment of the present disclosure. As shown in FIG. 3, the carbon dioxide capture system 200 in the second embodiment includes a carbon dioxide capture device 110, a heating steam generator 120, a process fluid heater 230, a tank storage line 140, and a control device 250. The process fluid heater 230 includes a heating steam line 23 , a reboiler 24 , a steam condensate line 25 , and a water quality monitor 40 .

[0035] (Water quality monitoring device) The water quality monitoring device 40 measures the water quality of the steam condensate discharged from the reboiler 24. An example of the water quality monitoring device 40 is a device that can measure the electrical conductivity, pH, TOC (total organic carbon), etc. of the steam condensate discharged from the reboiler 24. If the electrical conductivity, pH, or TOC of the steam condensate discharged from the reboiler 24 is outside a predetermined range, it can be determined that the water quality is abnormal. Note that the measurement of water quality by the water quality monitoring device 40 measures the water quality of flowing steam condensate, and therefore is less accurate than the inspection in the inspection step S20 of the first embodiment described above.

[0036] (How to drive) FIG. 4 is a flowchart showing a method for operating a carbon dioxide capture system in the second embodiment of the present disclosure. As shown in FIG. 4, the method of operating the carbon dioxide capture system 200 includes a tank supply step S10, an inspection step S20, a switching step S30, a monitoring step S40, and an evacuation step S50.

[0037] In the operation method of the carbon dioxide capture system 200 in the second embodiment, first, similarly to the first embodiment, a tank supply step S10, an inspection step S20, and a switching step S30 are performed at the start of the carbon dioxide capture device main body 111. Then, at the timing of transition to normal operation, a monitoring step S40 is started.

[0038] In the monitoring step S40, after the switching step S30, it is monitored whether or not the heating steam generator 120 is in a state where it can accept the steam condensate coming out of the reboiler 24. Examples of a state where the heating steam generator 120 cannot accept the steam condensate coming out of the reboiler 24 include a case where the water quality of the steam condensate coming out of the reboiler 24 measured by the water quality monitoring device 40 is abnormal, and a case where some kind of problem has occurred on the heating steam generator 120 side.

[0039] The monitoring in the monitoring step S40 may be automatically performed by, for example, the control device 250. In this case, the control device 250 receives information on the measurement result of the water quality monitoring device 40, and when the measurement result by the water quality monitoring device 40 is not within a predetermined range, it may notify an operator or the like of the water quality abnormality by an alarm device (not shown) or the like. In addition, the control device 250 may be capable of receiving an alarm signal output from the heating steam generator 120 when some problem occurs. Note that the water quality measurement by the water quality monitoring device 40 is not limited to being performed after the switching step S30, and may be performed, for example, from the start of the carbon dioxide capture device 110. Note that the control device 250 has the same configuration as the control device 150 of the first embodiment, except for the configuration related to the water quality monitoring device 40.

[0040] In the evacuation process S50, when it is determined in the monitoring process S40 that the heating steam generator 120 cannot accept the steam condensed water from the reboiler 24, the supply destination of the steam condensed water from the reboiler 24 is switched from the heating steam generator 120 to the tank 112 of the carbon dioxide capture device 110. In this second embodiment, as in the first embodiment, a case is illustrated in which the supply destination of the steam condensed water from the reboiler 24 is the process fluid tank 112A out of the process fluid tanks 112A and the chemical tanks 112B, 112C.

[0041] (Action and effect) According to the second embodiment, in addition to the effects of the first embodiment, after the carbon dioxide capture system 200 transitions to normal operation, if an abnormality in the water quality of the steam condensate coming out of the reboiler 24 occurs or some problem occurs in the heating steam generator 120, and the heating steam generator 120 cannot accept the steam condensate coming out of the reboiler 24, the supply destination of the steam condensate coming out of the reboiler 24 can be switched from the heating steam generator 120 to the tank 112 of the carbon dioxide capture device 110. Therefore, the capture of carbon dioxide by the carbon dioxide capture device 110 can be continued until the tank 112 is filled. Therefore, in the case of a false detection of a water quality abnormality or a temporary problem in the heating steam generator 120, the capture of carbon dioxide by the carbon dioxide capture device 110 can be prevented from being stopped.

[0042] (Other embodiments) The present disclosure is not limited to the configurations of the above-described embodiments, and design changes are possible without departing from the spirit of the present disclosure. Fig. 5 is a diagram showing a schematic configuration of a carbon dioxide capture system according to a first modified example of the embodiment of the present disclosure, and Fig. 6 is a diagram showing a schematic configuration of a carbon dioxide capture system according to a second modified example of the embodiment of the present disclosure. In the above first and second embodiments, the tank storage line 140 is connected only to the process fluid tank 112A. However, the tank 112 to which the tank storage line 140 is connected is not limited to the process fluid tank 112A. For example, as in the first modified example shown in FIG. 5, the tank storage line 140 may be connected to the chemical tank 112B or the chemical tank 112C. In this case, the steam condensed water can be used to dilute the chemical stored in the chemical tank 112B or the chemical stored in the chemical tank 112C. The reason why the steam condensed water can be used to dilute the chemical in this way is that even if the steam condensed water contains a process fluid or the like, the diluted chemical is treated in the carbon dioxide absorption system 200 in which the process fluid or the like is used. Note that FIG. 5 shows a case where the first modified example is applied to the first embodiment, but the same applies to a case where the first modified example is applied to the second embodiment.

[0043] In the above-described first and second embodiments, the case where one tank storage line 140 is connected to one tank 112 has been described, but the present invention is not limited to this configuration. For example, as in a second modified example shown in FIG. 6, a plurality of tank storage lines 140 may be provided so that the steam condensed water discharged from the reboiler 24 can be supplied to a plurality of tanks 112. In this manner, the amount of steam condensed water that can be stored can be increased compared to the case where the steam condensed water is stored in one tank 112. Note that, although FIG. 6 illustrates a case where the steam condensed water is supplied to three tanks 112, the number of tanks 112 that can store the steam condensed water is not limited to three. Also, FIG. 6 illustrates a case where the second modified example is applied to the first embodiment as in FIG. 5, but the same applies to the case where the second modified example is applied to the second embodiment.

[0044] In the above first and second embodiments, the case where one process fluid tank 112A is provided has been exemplified, but a plurality of process fluid tanks 112A may be provided. Similarly, a plurality of chemical tanks 112B may be provided, or a plurality of chemical tanks 112C may be provided. In this case, the tank storage line 140 may be connected only to the same type of tank 112, i.e., the plurality of process fluid tanks 112A, or the tank storage line 140 may be connected only to the plurality of chemical tanks 112B and 112C.

[0045] In the above embodiment, the process fluid tank 112A and the chemical tanks 112B and 112C are exemplified as the tank 112 used by the carbon dioxide capture apparatus main body 111. However, the tank 112 of the carbon dioxide capture apparatus 110 is not limited to the process fluid tank 112A and the chemical tanks 112B and 112C.

[0046] In the first embodiment, the second control valve 29 and the third control valve 31 may be replaced with a three-way valve.

[0047] In each of the above embodiments, the configuration in which the first control valve 28 to the third control valve 31 are automatically opened and closed by the control device 150, 250 has been exemplified, but the present invention is not limited to this configuration. For example, the control device 150, 250 may be omitted, and an operator may perform the valve opening and closing operations.

[0048] <Additional Notes> The carbon dioxide capture system and the operating method thereof described in the embodiment can be understood, for example, as follows.

[0049] (1) According to a first aspect, the carbon dioxide capture system 100, 200 comprises: an absorption tower 11 for absorbing carbon dioxide contained in a carbon dioxide-containing gas G into a process fluid; a regeneration tower 12 for heating the process fluid to separate carbon dioxide from the process fluid to regenerate the process fluid; a carbon dioxide capture apparatus main body 111 including a circulation line 13 for circulating the process fluid between the absorption tower 11 and the regeneration tower 12; a carbon dioxide capture apparatus 110 including tanks 112, 112A, 112B, 112C connected to the carbon dioxide capture apparatus main body 111; a heating steam generator 120 for generating heating steam; a process fluid heater 130, 230 including a reboiler 24 for heat exchange between the heating steam and the process fluid of the regeneration tower 12; and a tank storage line 140 for supplying steam condensate discharged from the reboiler 24 to the tanks 112, 112A, 112B, 112C of the carbon dioxide capture apparatus 110. Examples of the process fluid include an absorption liquid and an amine solution. Examples of the tank include a process fluid tank and a chemical tank. Examples of the carbon dioxide-containing gas include exhaust gas. Examples of the heating steam generator include a power generation facility and a boiler.

[0050] This makes it possible to avoid providing a dedicated tank for temporarily storing the steam condensed water and to prevent the steam condensed water from being returned to the heating steam generator 120. This makes it possible to suppress an increase in the number of tanks and to achieve space saving.

[0051] (2) According to a second aspect, the carbon dioxide capture system is the carbon dioxide capture system 100, 200 of (1), and is provided with a plurality of the tanks 112, 112A, 112B, 112C, and a plurality of tank storage lines 140 that supply steam condensate from the reboiler 24 to the plurality of the tanks 112, 112A, 112B, 112C. This allows the amount of steam condensed water that can be stored to be increased compared to the case where the steam condensed water is stored in one tank 112.

[0052] (3) According to a third aspect, the carbon dioxide capture system is the carbon dioxide capture system 100, 200 of (1) or (2), and includes, as the tank 112, at least one of a process fluid tank 112A that stores the process fluid used in the carbon dioxide capture device main body 111, and a chemical tank 112B, 112C that stores a chemical used in the carbon dioxide capture device main body 111, and the tank storage line 140 supplies the steam condensate discharged from the reboiler 24 to at least one of the process fluid tank 112A and the chemical tank 112B, 112C. Examples of chemicals include caustic soda and sulfuric acid. This allows the process fluid tank 112A to be used as tank 112 for storing steam condensate, and the steam condensate to be used to dilute the process fluid stored in process fluid tank 112 A. Also, the chemical tanks 112B and 112C can be used as tanks 112 for storing steam condensate, and the steam condensate to be used to dilute the chemicals stored in chemical tanks 112B and 112C.

[0053] (4) According to a fourth aspect, the carbon dioxide recovery system is any one of the carbon dioxide recovery systems 200 of (1) to (3), wherein the process fluid heater 230 further includes a water quality monitoring device 40 for measuring the water quality of the steam condensate discharged from the reboiler 24. This makes it possible to detect that the water quality of the steam condensate discharged from the reboiler 24 has become abnormal. Therefore, the steam condensate with abnormal water quality can be stored in the tank 112, and the steam condensate with abnormal water quality can be prevented from returning to the heating steam generator 120.

[0054] (5) According to a fifth aspect, the carbon dioxide recovery system is any one of the carbon dioxide recovery systems (1) to (4), and includes a control valve 29, 31 capable of switching between a state in which the steam condensate discharged from the reboiler 24 flows into the tanks 112, 112A, 112B, 112C via the tank storage line 140 and a state in which the steam condensate discharged from the reboiler 24 flows into the heating steam generator 120, and a control device 150, 250 that controls the operation of the control valve 29, 31. Examples of the control valve include a second control valve and a third control valve. This makes it possible to automatically switch the supply destination of the steam condensate, thereby reducing the burden on workers.

[0055] (6) According to a sixth aspect, a method for operating a carbon dioxide capture system includes a carbon dioxide capture apparatus main body 111 including an absorption tower 11 for absorbing carbon dioxide contained in a carbon dioxide-containing gas G into a process fluid, a regeneration tower 12 for heating the process fluid to separate carbon dioxide from the process fluid to regenerate the process fluid, and a circulation line 13 for circulating the process fluid between the absorption tower 11 and the regeneration tower 12, a carbon dioxide capture apparatus 110 including tanks 112, 112A, 112B, and 112C connected to the carbon dioxide capture apparatus main body 111, a heating steam generator 120 for generating heating steam, and a process fluid heater 130 including a reboiler 24 for exchanging heat between the heating steam and the process fluid in the regeneration tower 12, , 230, the method for operating the carbon dioxide capture system 100, 200 including the carbon dioxide capture apparatus 110 and the reboiler 24, the method including a tank supply process S10 for supplying the steam condensate discharged from the reboiler 24 to the tanks 112, 112A, 112B, 112C of the carbon dioxide capture apparatus 110 when the carbon dioxide capture apparatus main body 111 is started, an inspection process S20 for inspecting, in parallel with the tank supply process S10, whether the process fluid has been mixed into the steam condensate discharged from the reboiler 24, and a switching process S30 for switching the supply destination of the steam condensate discharged from the reboiler 24 from the tanks 112, 112A, 112B, 112C of the carbon dioxide capture apparatus 110 to the heating steam generator 120 when it is determined by the inspection process S20 that there is no mixing of the process fluid. Examples of the process fluid include an absorption liquid and an amine solution. Examples of the tank include a process fluid tank and a chemical tank. Examples of the carbon dioxide-containing gas include exhaust gas. Examples of the heating steam generator include a power generation facility and a boiler.

[0056] This eliminates the need to provide a dedicated tank for temporarily storing steam condensate during the inspection process S20, making it possible to suppress an increase in the number of tanks and save space.

[0057] (7) According to a seventh aspect, the operating method of the carbon dioxide capture system is the operating method of the carbon dioxide capture system of (6), and includes, after the switching step S30, a monitoring step S40 of monitoring whether the steam condensate output from the reboiler 24 is in a state where it can be accepted by the heating steam generator 120, and an evacuation step S50 of switching the supply destination of the steam condensate output from the reboiler 24 from the heating steam generator 120 to the tanks 112, 112A, 112B, 112C of the carbon dioxide capture system 110 when it is determined by the monitoring step S40 that it is not possible for the steam condensate to be accepted by the heating steam generator 120. As a result, even if the heating steam generator 120 temporarily becomes unable to accept the steam condensate after the switching step S30, the carbon dioxide capture device main body 111 can continue to capture the carbon dioxide.

[0058] (8) According to an eighth aspect, the method of operating a carbon dioxide recovery system is the method of operating a carbon dioxide recovery system of (6) or (7), and in the tank supply step S10, the process fluid is diluted using steam condensate from the reboiler 24. This allows the steam condensate, whose quality is not guaranteed, to be effectively used as water for diluting the process fluid.

[0059] (9) According to a ninth aspect, the method of operating a carbon dioxide recovery system is the method of operating a carbon dioxide recovery system of (6) or (7), and in the tank supply step S10, the steam condensate discharged from the reboiler 24 is used to dilute a chemical used in the carbon dioxide recovery device main body 111. This allows steam condensate, the quality of which is not guaranteed, to be used to dilute chemicals. [Explanation of symbols]

[0060] 11...absorption tower 12...regeneration tower 13...circulation line 14...cooling tower 15...carbon dioxide-containing gas supply line 16...rich liquid line 17...lean liquid line 19...process fluid evacuation line 20...first chemical supply line 21...second chemical supply line 23...heating steam line 24...reboiler 25...steam condensate line 28...first control valve 29...second control valve 31...third control valve 40...water quality monitoring device 100,200,300,400...carbon dioxide capture system 110...carbon dioxide capture device 111...carbon dioxide capture device main body 112...tank 112A...process fluid tank 112B,112C...chemical tank 120...heating steam generator 130,230...process fluid heater 140...tank storage line 150,250...control device G...carbon dioxide-containing gas S10...tank supply process S20: Inspection process S30: Switching process S40: Monitoring process S50: Evacuation process

Claims

1. an absorption tower that absorbs carbon dioxide contained in the carbon dioxide-containing gas into a process fluid; a regeneration tower that regenerates the process fluid by heating the process fluid and separating carbon dioxide from the process fluid; a circulation line for circulating the process fluid between the absorption tower and the regeneration tower; a carbon dioxide capture device body comprising: a carbon dioxide capture device having a tank connected to the carbon dioxide capture device main body; a heating steam generator that generates heating steam; a process fluid heater having a reboiler for heat exchange between the heating steam and the process fluid in the regeneration tower; a tank storage line that supplies steam condensate from the reboiler to the tank of the carbon dioxide capture device; Equipped with The carbon dioxide capture system, wherein the tank is at least one of a process fluid tank that stores the process fluid used in the carbon dioxide capture device main body, and a chemical tank that stores chemicals used in the carbon dioxide capture device main body.

2. A plurality of the tanks is provided, A plurality of tank storage lines are provided to supply the steam condensate discharged from the reboiler to the plurality of tanks. The carbon dioxide capture system of claim 1 .

3. The tank storage line supplies the steam condensate from the reboiler to at least one of the process fluid tank and the chemical tank.

3. The carbon dioxide recovery system according to claim 1 or 2.

4. The process fluid heater further includes a water quality monitor that measures the quality of steam condensate discharged from the reboiler.

3. The carbon dioxide recovery system according to claim 1 or 2.

5. a control valve capable of switching between a state in which the steam condensate discharged from the reboiler flows into the tank via the tank storage line and a state in which the steam condensate discharged from the reboiler flows into the heating steam generating device; a control device for controlling the operation of the control valve; 3. The carbon dioxide recovery system according to claim 1 or 2.

6. an absorption tower that absorbs carbon dioxide contained in the carbon dioxide-containing gas into a process fluid; a regeneration tower that regenerates the process fluid by heating the process fluid and separating carbon dioxide from the process fluid; a circulation line for circulating the process fluid between the absorption tower and the regeneration tower; a carbon dioxide capture device body comprising: a carbon dioxide capture device having a tank connected to the carbon dioxide capture device main body; a heating steam generator that generates heating steam; a process fluid heater having a reboiler that exchanges heat between the heating steam and the process fluid in the regeneration tower, a tank supply step of supplying the steam condensate discharged from the reboiler to the tank of the carbon dioxide recovery device when the carbon dioxide recovery device main body is started; a step of inspecting, in parallel with the tank supply step, whether the process fluid is mixed into the steam condensate discharged from the reboiler; and a switching step of switching a supply destination of the steam condensate discharged from the reboiler from the tank of the carbon dioxide recovery device to the heating steam generator when it is determined by the inspection step that there is no mixing of the process fluid. How to operate a carbon dioxide capture system.

7. a monitoring step of monitoring whether the heating steam generating device is in a state where it can accept the steam condensate discharged from the reboiler after the switching step; and an evacuation step of switching a supply destination of the steam condensate discharged from the reboiler from the heating steam generator to the tank of the carbon dioxide capture device when it is determined by the monitoring step that the steam condensate cannot be received by the heating steam generator. A method for operating a carbon dioxide capture system according to claim 6.

8. In the tank supply step, the process fluid is diluted with steam condensate from the reboiler. A method for operating a carbon dioxide recovery system according to claim 6 or 7.

9. In the tank supply step, the chemicals used in the carbon dioxide recovery device main body are diluted with the steam condensate from the reboiler. A method for operating a carbon dioxide recovery system according to claim 6 or 7.

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