JP5331587B2 - Carbon dioxide recovery system - Google Patents

Description

  The present invention relates to a carbon dioxide recovery system.

  In a thermal power plant that uses a large amount of fossil fuel, the combustion exhaust gas generated by burning fossil fuel is brought into contact with an amine-based absorbent, and carbon dioxide is separated and recovered from the combustion exhaust gas. Research has been conducted on how to store carbon without releasing it into the atmosphere.

  Specifically, an absorption tower that absorbs carbon dioxide contained in combustion exhaust gas in an amine-based absorption liquid and an absorption liquid (rich liquid) that has absorbed carbon dioxide are supplied from the absorption tower, the rich liquid is heated, and the rich liquid A carbon dioxide recovery system including a regeneration tower for releasing carbon dioxide gas from the water and regenerating an absorbing solution is known (see, for example, Patent Document 1).

  In the carbon dioxide recovery system as described above, the absorbing liquid also takes in moisture in the combustion exhaust gas when absorbing carbon dioxide in the combustion exhaust gas in the absorption tower. For this reason, there has been a problem in that the moisture ratio of the absorbent increases with time, and the carbon dioxide absorption performance of the absorbent decreases.

JP-A-2005-254212

  An object of this invention is to provide the carbon dioxide collection system which can prevent the fall of the carbon dioxide absorption performance of absorption liquid.

  A carbon dioxide recovery system according to an aspect of the present invention is provided with an absorption tower that absorbs carbon dioxide contained in combustion exhaust gas into an absorption liquid, an absorption liquid that absorbs carbon dioxide from the absorption tower, and vapor from the absorption liquid. A regeneration tower that discharges carbon dioxide gas contained therein and regenerates the absorption liquid; and a regenerated absorption liquid that is provided between the absorption tower and the regeneration tower and that is supplied from the regeneration tower to the absorption tower. As described above, a regeneration heat exchanger that heats an absorption liquid that has absorbed carbon dioxide supplied from the absorption tower to the regeneration tower, and an exhaust gas discharged from the regeneration tower are condensed, and the generated condensate is separated. Based on at least one of a condenser, an adjustment valve for adjusting the discharge amount of the condensate to the outside, and a moisture ratio of the absorption liquid and a composition analysis value, the discharge amount is obtained and the adjustment valve is controlled. Control signal A control unit for outputting those with a.

  A carbon dioxide recovery system according to an aspect of the present invention absorbs carbon dioxide contained in combustion exhaust gas in an absorption liquid and absorbs carbon dioxide from the absorption tower that discharges combustion exhaust gas from which carbon dioxide has been removed. The absorption liquid is supplied, the carbon dioxide gas containing the vapor is discharged from the absorption liquid, the regeneration tower that regenerates the absorption liquid, and is provided between the absorption tower and the regeneration tower. Using the regenerated absorption liquid supplied to the absorption tower as a heat source, a regenerative heat exchanger that heats the absorption liquid that has absorbed carbon dioxide supplied from the absorption tower to the regeneration tower, and combustion discharged from the absorption tower At least one of a condenser for condensing exhaust gas and separating the generated condensate, a regulating valve for adjusting the discharge amount of the condensate to the outside, a moisture ratio and composition analysis value of the absorption liquid Based obtains the emissions, in which and a control unit for outputting a control signal for controlling the regulator valve.

  A carbon dioxide recovery system according to an aspect of the present invention is provided with an absorption tower that absorbs carbon dioxide contained in combustion exhaust gas into an absorption liquid, an absorption liquid that absorbs carbon dioxide from the absorption tower, and vapor from the absorption liquid. A regeneration tower that discharges carbon dioxide gas contained therein and regenerates the absorption liquid; and a regenerated absorption liquid that is provided between the absorption tower and the regeneration tower and that is supplied from the regeneration tower to the absorption tower. As described above, a regeneration heat exchanger that heats an absorption liquid that has absorbed carbon dioxide supplied from the absorption tower to the regeneration tower, and an exhaust gas discharged from the regeneration tower are condensed, and the generated condensate is separated. A condenser, a regulating valve for adjusting the amount of the condensate discharged to the outside, a first sensor for measuring the temperature, flow rate, and humidity of the combustion exhaust gas supplied to the absorption tower, and the absorption tower Exhausted combustion A second sensor for measuring the temperature, flow rate and humidity of the gas; a third sensor for measuring the temperature, flow rate and humidity of the gas discharged from the condenser; and the first, second and second sensors. And an arithmetic control unit that calculates the discharge amount based on the measurement result of the sensor 3 and outputs a control signal for controlling the regulating valve.

  A carbon dioxide recovery system according to an aspect of the present invention is provided with an absorption tower that absorbs carbon dioxide contained in combustion exhaust gas into an absorption liquid, an absorption liquid that absorbs carbon dioxide from the absorption tower, and vapor from the absorption liquid. A regeneration tower that discharges carbon dioxide gas contained therein and regenerates the absorption liquid; and a regenerated absorption liquid that is provided between the absorption tower and the regeneration tower and that is supplied from the regeneration tower to the absorption tower. As described above, a regeneration heat exchanger that heats an absorption liquid that has absorbed carbon dioxide supplied from the absorption tower to the regeneration tower, and an exhaust gas discharged from the regeneration tower are condensed, and the generated condensate is separated. A condenser, a regulating valve for adjusting the discharge amount of the condensate to the outside, a first sensor for measuring the temperature of the absorbing liquid, the density, viscosity, surface tension, thermal conductivity of the absorbing liquid, and At least one of the specific heat The discharge amount is calculated based on a second sensor that measures one physical property value, a correspondence relationship between the temperature of the absorbing liquid having a predetermined concentration and the physical property value, and measurement results of the first and second sensors. And an arithmetic control unit that outputs a control signal for controlling the regulating valve.

  According to the present invention, it is possible to prevent a decrease in carbon dioxide absorption performance of the absorbing liquid.

1 is a schematic configuration diagram of a carbon dioxide recovery system according to a first embodiment of the present invention. It is a schematic block diagram of the carbon dioxide collection system by a modification. It is a schematic block diagram of the carbon dioxide collection system which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of the carbon dioxide recovery system which concerns on the 3rd Embodiment of this invention. It is a graph which shows an example of the relationship between the temperature of an absorption liquid, and a density. It is a graph which shows an example of the relationship between the temperature of an absorption liquid, and a viscosity. It is a graph which shows an example of the relationship between the temperature of absorption liquid, and surface tension. It is a graph which shows an example of the relationship between the temperature of absorption liquid, and thermal conductivity. It is a graph which shows an example of the relationship between the temperature of absorption liquid, and a specific heat.

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

  (First Embodiment) FIG. 1 shows a schematic configuration of a carbon dioxide recovery system according to a first embodiment of the present invention. Here, the carbon dioxide recovery system recovers carbon dioxide contained in combustion exhaust gas generated by the combustion of fossil fuel using an absorbing liquid capable of absorbing carbon dioxide.

  As shown in FIG. 1, the carbon dioxide recovery system 1 includes an absorption tower 3 that absorbs carbon dioxide contained in the combustion exhaust gas 2a into an absorption liquid, and an absorption liquid that absorbs carbon dioxide from the absorption tower 3 (hereinafter, rich liquid 4a and A regenerating tower that heats the rich liquid 4a, releases carbon dioxide gas containing vapor from the absorbing liquid, discharges exhaust gas 2c containing carbon dioxide gas and steam, and regenerates the absorbing liquid 5. For example, the combustion exhaust gas 2a generated in a power generation facility such as a thermal power plant is supplied to the lower part of the absorption tower 3, and the combustion exhaust gas 2b from which carbon dioxide has been removed is discharged from the top of the absorption tower 3. .

  The absorption tower 3 has an absorption tower tank 3a for storing the rich liquid 4a generated by the absorption liquid absorbing carbon dioxide. Similarly, the regeneration tower 5 has a regeneration tower tank 5a that stores an absorbing liquid regenerated by releasing the carbon dioxide gas from the rich liquid 4a (hereinafter referred to as a lean liquid 4b).

  Here, as the absorbing solution capable of absorbing carbon dioxide, for example, an amine compound aqueous solution in which an amine compound is dissolved in water is used. The concentration (water ratio) of the amine compound aqueous solution is set to a value suitable for the separation and recovery of carbon dioxide.

  As shown in FIG. 1, a reboiler 6 is provided in the regeneration tower 5. The reboiler 6 generates a steam by heating a part of the lean liquid 4b stored in the regeneration tower tank 5a by using plant steam or the like supplied from the power generation equipment as a heat source to increase the temperature thereof. To supply. When heating the lean solution 4b in the reboiler 6, a small amount of carbon dioxide gas is released from the lean solution 4b and supplied to the regeneration tower 5 together with the vapor. Then, the rich liquid 4a is heated in the regeneration tower 5 by this steam, and carbon dioxide gas is released.

  A condenser 17 that condenses (cools) the exhaust gas 2c containing carbon dioxide gas and steam discharged from the regeneration tower 5 and separates the carbon dioxide gas and the generated condensate (condensed water) is provided in the regeneration tower 5. It is connected to. The carbon dioxide gas 2d discharged from the condenser 17 is stored in a storage facility (not shown).

  A gas cooling line 15 for supplying the exhaust gas 2c discharged from the regeneration tower 5 to the condenser 17 is connected between the regeneration tower 5 and the condenser 17, and a cooling water (cooling medium) is connected to the gas cooling line 15. Is used to cool the exhaust gas 2c. A condensate line 18 for supplying the condensate from the condenser 17 to the upper part of the regenerator 5 is connected between the condenser 17 and the regenerator 5, and the condensate line 18 from the condenser 17 is connected to the condensate line 18. A condensate pump 19 for feeding the condensate to the regeneration tower 5 is provided.

  The condensate line 18 is provided with an adjusting valve 20 that can discharge the condensate to the outside.

  Regeneration heat exchange between the absorption tower 3 and the regeneration tower 5 using the lean liquid 4b supplied from the regeneration tower 5 to the absorption tower 3 as a heat source and heating the rich liquid 4a supplied from the absorption tower 3 to the regeneration tower 5. A vessel 7 is provided and configured to recover the heat of the lean liquid 4b. Here, as described above, when the carbon dioxide gas is released from the rich liquid 4 a in the regeneration tower 5, the rich liquid 4 a is heated using high-temperature steam from the reboiler 6 as a heat source. Accordingly, the temperature of the lean liquid 4b supplied to the regenerative heat exchanger 7 is relatively high, and this lean liquid 4b is used as a heat source.

  A first rich liquid line 8 for supplying the rich liquid 4a from the bottom of the absorption tower tank 3a to the regenerative heat exchanger 7 is connected between the absorption tower 3 and the regenerative heat exchanger 7. A rich liquid pump 9 for sending the rich liquid 4 a from the absorption tower 3 to the regenerative heat exchanger 7 is provided in the first rich liquid line 8.

  Between the regeneration heat exchanger 7 and the regeneration tower 5, a second rich liquid line 10 for supplying the rich liquid 4a from the regeneration heat exchanger 7 to the upper portion of the regeneration tower 5 is connected. The second rich liquid line 10 is provided with a valve 13 for increasing the pressure of the rich liquid. By increasing the pressure of the rich liquid using the valve 13, it is possible to suppress the carbon dioxide from being separated from the rich liquid in the regenerative heat exchanger 7 and the heat exchange rate from being lowered due to the two-phase flow.

  Between the regeneration tower 5 and the regeneration heat exchanger 7, a first lean liquid line 11 for supplying the lean liquid 4b to the regeneration heat exchanger 7 from the bottom of the regeneration tower tank 5a is connected.

  The lean liquid 4 b from the regenerative heat exchanger 7 is sent to the absorbing liquid cooler 14 by the lean liquid pump 12. The absorption liquid cooler 14 uses the cooling water (cooling medium) as a cooling source and cools the lean liquid 4b. The lean liquid 4 c cooled by the absorption liquid cooler 14 is supplied to the upper part of the absorption tower 3.

  The lean liquid 4 c supplied to the upper part of the absorption tower 3 descends from the upper part toward the absorption tower tank 3 a in the absorption tower 3. On the other hand, the combustion exhaust gas 2 a supplied to the absorption tower 3 rises from the lower part toward the top in the absorption tower 3. Therefore, the combustion exhaust gas 2a containing carbon dioxide and the lean liquid come into countercurrent contact (direct contact), and carbon dioxide is removed from the combustion exhaust gas 2a and absorbed by the lean liquid, thereby generating the rich liquid 4a. The combustion exhaust gas 2b from which carbon dioxide has been removed is discharged from the top of the absorption tower 3, and the rich liquid 4a is stored in the absorption tower tank 3a of the absorption tower 3.

  Usually, the combustion exhaust gas 2a is supplied at a temperature lowered to the optimum temperature for carbon dioxide absorption in the absorption tower 3, and the gas is in a state of almost saturated humidity. Moreover, the liquid in the exit gas from the absorption tower 3 is returned in the absorption tower 3 by demister and cooling in order to prevent scattering of the absorption liquid. Although a portion corresponding to the vapor pressure of water is discharged from the top of the absorption tower 3, most of the steam (water) is returned to the absorption tower 3. Therefore, most of the water in the combustion exhaust gas 2a is taken into the absorption liquid, and the moisture ratio of the absorption liquid increases.

In the present embodiment, the condensate (water) is discharged by the regulating valve 20 to keep the moisture ratio of the absorbing liquid constant. The discharge amount of the condensate can be calculated based on the moisture ratio (or composition analysis value) of the absorption liquid. For example, the moisture ratio of the lean liquid 4c is measured by gas chromatography or the like, and the amount of condensate discharged can be determined from the difference from the moisture ratio of the absorbing liquid at the start of operation. For example, by measuring the water ratio when the time ΔT has elapsed, the amount of water increase ΔW in the absorbing liquid at the time ΔT can be known, and the condensate discharge amount V per unit time can be obtained by the following equation.
V = ΔW / ΔT

  The regulating valve 20 is adjusted so that the discharge amount per unit time becomes V. Calculation of this equation and control of the regulating valve 20 may be performed by an arithmetic control unit (not shown).

  In this way, by discharging the condensate to the outside from the condenser 17 at the top of the regeneration tower 5 by the regulating valve 20, the water ratio of the absorption liquid is kept constant, so that the carbon dioxide absorption performance of the absorption liquid is reduced. Can be prevented.

  In this embodiment, the condensate in the condenser 17 at the top of the regeneration tower 5 is discharged to the outside. However, as shown in FIG. 2, the condensate in the condenser 22 provided at the top of the absorption tower 3 is discharged to the outside. You may make it discharge | emit. A line 23 for supplying combustion exhaust gas 2b discharged from the top of the absorption tower 3 to the condenser 22 is connected between the absorption tower 3 and the condenser 22, and a cooling medium such as cooling water is used for the line 23. A gas cooler 24 for cooling the combustion exhaust gas 2b is provided. Further, a condensate line 25 for supplying the condensate from the condenser 22 to the upper part of the absorption tower 3 is connected between the condenser 22 and the absorption tower 3, and the condensate line 25 from the condenser 22 is connected to the condensate line 25. A condensate pump 26 for sending the condensate to the absorption tower 3 is provided. The regulating valve 20 is provided in the condensate line 25 so that the condensate can be discharged to the outside. Even with such a configuration, it is possible to keep the moisture ratio of the absorbing liquid constant and prevent the carbon dioxide absorbing performance of the absorbing liquid from deteriorating.

  (Second Embodiment) FIG. 3 shows a schematic configuration of a carbon dioxide recovery system according to a second embodiment of the present invention. This embodiment is the same as the first embodiment shown in FIG. 1 except that an arithmetic control unit 30, temperature sensors 31 to 33, flow rate sensors 34 to 36, and humidity sensors 37 to 39 are further provided. It has become. In FIG. 3, the same parts as those of the first embodiment shown in FIG.

  The temperature sensor 31, the flow sensor 34, and the humidity sensor 37 measure the temperature, flow rate, and humidity of the combustion exhaust gas 2a, respectively, and notify the calculation control unit 30 of the measurement results.

  The temperature sensor 32, the flow rate sensor 35, and the humidity sensor 38 measure the temperature, flow rate, and humidity of the flue gas 2b discharged from the top of the absorption tower 3, and notify the calculation control unit 30 of the measurement results.

  The temperature sensor 33, the flow sensor 36, and the humidity sensor 39 measure the temperature, flow rate, and humidity of the carbon dioxide gas 2d discharged from the condenser 17 and notify the calculation control unit 30 of the measurement results.

  The arithmetic control unit 30 calculates the amount of condensate to be discharged to the outside using the measurement results notified from the temperature sensors 31 to 33, the flow rate sensors 34 to 36, and the humidity sensors 37 to 39, and adjusts the control valve. A control signal is output to 20.

The amount of the condensate to be discharged to the outside is equal to the amount of water in the combustion exhaust gas taken into the absorption liquid. The arithmetic control unit 30 obtains the amount Wc of water in the combustion exhaust gas taken into the absorbent per unit time using the following formula. The flow rate of the combustion exhaust gas 2a at the inlet of the absorption tower 3 is Qi, the humidity is Ci, the flow rate of the gas 2b at the outlet of the absorption tower 3 is Qo, the humidity is Co, the flow rate of the gas 2d at the outlet of the condenser 17 is Qs, and the humidity is Cs. . Since the combustion exhaust gases 2a, 2b and the carbon dioxide gas 2d have different temperatures, the flow rates Qi, Qo, Qs are temperature-corrected based on the measurement results of the temperature sensors 31-33.
Wc = QiCi-QoCo-QsCs

  The arithmetic control unit 30 outputs a control signal to the adjustment valve 20 so that the condensate discharge amount per unit time becomes Wc.

  Thereby, the moisture ratio of the absorbing solution can be kept constant, and the carbon dioxide absorbing performance of the absorbing solution can be prevented from being lowered.

  By measuring the moisture ratio of the absorbing liquid at a predetermined time by gas chromatography etc. and reflecting the comparison result with the moisture ratio at the beginning of operation in the condensate discharge amount, the moisture ratio of the absorbing liquid can be controlled more accurately. Can do.

  In the present embodiment, the example using the carbon dioxide recovery system shown in FIG. 1 has been described, but the present invention can also be applied to the carbon dioxide recovery system shown in FIG.

  (Third Embodiment) FIG. 4 shows a schematic configuration of a carbon dioxide recovery system according to a third embodiment of the present invention. This embodiment is the same as the first embodiment shown in FIG. 1 except that an arithmetic control unit 40, a temperature sensor 41, and a physical property sensor 42 are further provided. In FIG. 4, the same parts as those of the first embodiment shown in FIG.

  The temperature sensor 41 measures the temperature of the lean liquid 4 c and notifies the calculation control unit 40 of the measurement result.

  The physical property value sensor 42 measures the physical property value of the lean liquid 4 c and notifies the calculation control unit 40 of the measurement result. Here, the physical property value measured by the physical property sensor 42 is any one of density, viscosity, surface tension, thermal conductivity, and specific heat.

  The arithmetic control unit 40 has a storage unit (not shown) that stores the correspondence between the temperature and the physical property value for each concentration of the absorbing liquid (amine compound aqueous solution). A control signal for controlling the condensate discharge amount is generated from the measurement results notified from the sensor 41 and the physical property sensor 42 and is output to the regulating valve 20.

  FIG. 5 shows an example of a correspondence relationship between temperature and density for each concentration of the amine compound aqueous solution. For example, when the amine concentration set value (at the start of operation) of the absorbing liquid is 50 wt% and the measurement results of the sensors 41 and 42 are point A, the condensate discharge amount is adjusted so as to approach 50 wt% indicated by an arrow. Control. If the amine density is greater than the water density, control is performed to reduce condensate discharge. On the contrary, when the density of amine is smaller than the density of water, it controls to increase the condensate discharge amount.

  FIG. 6 shows an example of the correspondence relationship between the temperature and the viscosity for each concentration of the amine compound aqueous solution. FIG. 7 shows an example of the correspondence between the temperature and surface tension for each concentration of the amine compound aqueous solution. FIG. 8 shows an example of the correspondence between the temperature and the thermal conductivity for each concentration of the amine compound aqueous solution. FIG. 9 shows an example of a correspondence relationship between the temperature and specific heat for each concentration of the amine compound aqueous solution.

  By grasping the relationship between the temperature and the physical property value at each amine concentration in advance and controlling the condensate discharge amount so that the measurement results of the sensors 41 and 42 approach the set value (ideal value), The moisture ratio of the absorbing liquid can be maintained.

  As described above, the carbon dioxide recovery system according to the present embodiment can keep the moisture ratio of the absorbing solution constant, prevent the absorbing solution from deteriorating in carbon dioxide absorption performance, and improve the stability of operation.

  In addition, it is preferable that the sensors 41 and 42 perform measurement in the absorption liquid supply line from the regeneration tower 5 to the absorption tower 3 in which almost no carbon dioxide is contained in the absorption liquid.

  In this embodiment, an example of measuring any one of density, viscosity, surface tension, thermal conductivity, and specific heat as a physical property value has been described. However, control of discharge amount by measuring two or more physical property values. You may make it use for.

  In the present embodiment, the example using the carbon dioxide recovery system shown in FIG. 1 has been described, but the present invention can also be applied to the carbon dioxide recovery system shown in FIG.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Carbon dioxide recovery system 3 Absorption tower 5 Regeneration tower 6 Reboiler 7 Regenerative heat exchanger 14 Gas cooler 17 Condenser (gas-liquid separator)
20 Regulating valve

Claims (5)

An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid;
An absorption liquid that has absorbed carbon dioxide from the absorption tower is supplied, a carbon dioxide gas containing steam is discharged from the absorption liquid, and a regeneration tower that regenerates the absorption liquid;
The carbon dioxide supplied from the absorption tower to the regeneration tower is absorbed by the regenerated absorption liquid provided between the absorption tower and the regeneration tower and supplied from the regeneration tower to the absorption tower as a heat source. A regenerative heat exchanger for heating the absorption liquid;
A condenser for condensing the exhaust gas discharged from the regeneration tower and separating the generated condensate;
An adjusting valve for adjusting the amount of the condensate discharged to the outside;
A control unit for obtaining the discharge amount based on at least one of a moisture ratio and a composition analysis value of the absorption liquid and outputting a control signal for controlling the adjustment valve;
A carbon dioxide recovery system. An absorption tower for absorbing the carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the combustion exhaust gas from which the carbon dioxide has been removed;
An absorption liquid that has absorbed carbon dioxide from the absorption tower is supplied, a carbon dioxide gas containing steam is discharged from the absorption liquid, and a regeneration tower that regenerates the absorption liquid;
The carbon dioxide supplied from the absorption tower to the regeneration tower is absorbed by the regenerated absorption liquid provided between the absorption tower and the regeneration tower and supplied from the regeneration tower to the absorption tower as a heat source. A regenerative heat exchanger for heating the absorption liquid;
A condenser for condensing the combustion exhaust gas discharged from the absorption tower and separating the produced condensate;
An adjusting valve for adjusting the amount of the condensate discharged to the outside;
A control unit for obtaining the discharge amount based on at least one of a moisture ratio and a composition analysis value of the absorption liquid and outputting a control signal for controlling the adjustment valve;
A carbon dioxide recovery system.   The carbon dioxide recovery system according to claim 1 or 2, wherein the moisture ratio of the absorption liquid is a moisture ratio of the regenerated absorption liquid supplied from the regeneration tower to the absorption tower. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid;
An absorption liquid that has absorbed carbon dioxide from the absorption tower is supplied, a carbon dioxide gas containing steam is discharged from the absorption liquid, and a regeneration tower that regenerates the absorption liquid;
The carbon dioxide supplied from the absorption tower to the regeneration tower is absorbed by the regenerated absorption liquid provided between the absorption tower and the regeneration tower and supplied from the regeneration tower to the absorption tower as a heat source. A regenerative heat exchanger for heating the absorption liquid;
A condenser for condensing the exhaust gas discharged from the regeneration tower and separating the generated condensate;
An adjusting valve for adjusting the amount of the condensate discharged to the outside;
A first sensor for measuring the temperature, flow rate, and humidity of the flue gas supplied to the absorption tower;
A second sensor for measuring the temperature, flow rate, and humidity of the flue gas discharged from the absorption tower;
A third sensor for measuring the temperature, flow rate and humidity of the gas discharged from the condenser;
An arithmetic control unit that calculates the discharge amount based on the measurement results of the first, second, and third sensors and outputs a control signal that controls the regulating valve;
A carbon dioxide recovery system. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid;
An absorption liquid that has absorbed carbon dioxide from the absorption tower is supplied, a carbon dioxide gas containing steam is discharged from the absorption liquid, and a regeneration tower that regenerates the absorption liquid;
The carbon dioxide supplied from the absorption tower to the regeneration tower is absorbed by the regenerated absorption liquid provided between the absorption tower and the regeneration tower and supplied from the regeneration tower to the absorption tower as a heat source. A regenerative heat exchanger for heating the absorption liquid;
A condenser for condensing the exhaust gas discharged from the regeneration tower and separating the generated condensate;
An adjusting valve for adjusting the amount of the condensate discharged to the outside;
A first sensor for measuring the temperature of the absorbing liquid;
A second sensor that measures at least one physical property value of the density, viscosity, surface tension, thermal conductivity, and specific heat of the absorbing liquid;
The discharge amount is calculated on the basis of the correspondence between the temperature and the physical property value in the absorbing liquid having a predetermined concentration and the measurement results of the first and second sensors, and a control signal for controlling the adjustment valve is output. An arithmetic control unit;
A carbon dioxide recovery system.

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