JP5606469B2 - Carbon dioxide recovery apparatus and method - Google Patents

Description

  Embodiments described herein relate generally to a carbon dioxide recovery apparatus and method.

  In recent years, as one of the causes of global warming, the greenhouse effect of carbon dioxide contained in combustion exhaust gas generated when burning fossil fuel has been pointed out. To address this issue, countries are working to reduce greenhouse gas emissions in accordance with the Kyoto Protocol to the United Nations Framework Convention on Climate Change.

  Under such circumstances, in a thermal power plant that uses a large amount of fossil fuel, the combustion exhaust gas produced by burning fossil fuel is brought into contact with the amine-based absorbent, and carbon dioxide is separated and recovered from the combustion exhaust gas. However, a method for storing the recovered carbon dioxide without releasing it into the atmosphere has been studied.

  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. A reboiler for supplying a heat source is connected to the regeneration tower. The absorption liquid (lean liquid) regenerated in the regeneration tower is supplied to the absorption tower, and the absorption liquid circulates in this system. In order to completely release carbon dioxide from the absorption liquid in the regeneration tower, a great deal of heat energy is required, so that carbon dioxide remains to some extent in the lean liquid.

  NOx and SOx that have not been removed in the denitration and desulfurization processes are present in the combustion exhaust gas, and are accumulated as inorganic acids (inorganic acid ions) in the absorption liquid. Moreover, an organic acid (organic acid ion) is produced | generated when the amine in an absorption liquid decomposes | disassembles, and accumulate | stores in an absorption liquid. In order to remove these organic and inorganic acids, a carbon dioxide recovery system provided with an ion exchange tower filled with an ion exchange resin is known.

  In such an ion exchange column, it is known that carbon dioxide is also removed as carbonate ions together with organic acids and inorganic acids, and the adsorption performance is such that inorganic acid ions> carbonate ions ≧ organic acid ions. That is, since inorganic acid ions such as sulfate ions and nitrate ions have higher selectivity than carbonate ions, even if carbonate ions are present in a large amount in the absorbent, they can be efficiently removed in the ion exchange column. On the other hand, the selectivity of organic acid ions such as formic acid and acetic acid is about the same as or lower than that of carbonate ions. Therefore, when a large amount of carbonate ions are present in the absorbing solution, The amount of adsorbed was reduced and could not be removed efficiently.

  Therefore, in order to efficiently remove both inorganic acid ions and organic acid ions in the conventional carbon dioxide recovery system, the size of the ion exchange column is increased to increase the adsorption capacity, or the regeneration of the ion exchange resin is frequently performed. Or the carbon dioxide in the absorbent must be removed sufficiently. However, when the size of the ion exchange tower is increased, there is a problem that the cost increases. Further, when the ion exchange resin is regenerated frequently, there is a problem that the amount of waste liquid increases. Further, as described above, there is a problem that a great deal of heat energy is required to sufficiently remove carbon dioxide in the absorbing solution.

JP 2008-238113 A

  The problem to be solved by the present invention is to suppress the increase in the size of the ion exchange tower, the regeneration frequency of the ion exchange resin, and the increase in the thermal energy supplied to the regeneration tower, while improving the efficiency of the inorganic and organic acids in the absorption liquid. An object of the present invention is to provide a carbon dioxide recovery apparatus and method that can be removed well.

  According to this embodiment, the carbon dioxide recovery device absorbs carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharges the absorption liquid containing carbon dioxide, and the absorption liquid discharged from the absorption tower. The carbon dioxide gas containing the vapor is removed from the absorption liquid, the regeneration tower that regenerates and discharges the absorption liquid, and at least part of the absorption liquid discharged from the regeneration tower is decompressed to absorb the absorption A pressure regulator for releasing carbon dioxide gas from the liquid, and an absorption liquid from which carbon dioxide gas is released by the pressure regulator are supplied, and inorganic acid ions and organic acid ions are removed from the absorption liquid to the absorption tower. An ion exchange unit to be supplied.

1 is a schematic configuration diagram of a carbon dioxide recovery device according to a first embodiment of the present invention. It is a schematic block diagram of the carbon dioxide recovery apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of the carbon dioxide recovery apparatus which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram of the carbon dioxide collection device by a modification.

  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 apparatus according to a first embodiment of the present invention. The carbon dioxide recovery apparatus 100 is supplied with an absorption tower 103 that absorbs carbon dioxide contained in the combustion exhaust gas 102a into an absorption liquid, and an absorption liquid that absorbs carbon dioxide from the absorption tower 103 (hereinafter referred to as a rich liquid 104a). The rich liquid 104a is heated to release carbon dioxide gas containing vapor from the absorbing liquid, and an exhaust gas 102c containing carbon dioxide gas and steam is discharged, and a regeneration tower 105 that regenerates the absorbing liquid is provided.

  For example, the combustion exhaust gas 102a generated in a power generation facility such as a thermal power plant is supplied to the lower part of the absorption tower 103, and the combustion exhaust gas 102b from which carbon dioxide has been removed is discharged from the top of the absorption tower 103. . For example, an amine compound aqueous solution is used as the absorbing solution capable of absorbing carbon dioxide.

  The reboiler 106 heats a part of the lean liquid 104 b stored in the regeneration tower tank 105 to increase its temperature to generate steam, and supplies the steam to the regeneration tower 105. When heating the lean solution 104b in the reboiler 106, a small amount of carbon dioxide gas is released from the lean solution 104b and supplied to the regeneration tower 105 together with the vapor. Then, the rich liquid 104a is heated in the regeneration tower 105 by this steam, and carbon dioxide gas is released.

  The lean liquid 104b discharged from the regeneration tower 105 is supplied to the pressure regulator 120. A pressure reducing pump 124 is connected to the pressure regulator 120 via a valve 123 so that the pressure in the pressure regulator 120 can be reduced. The amount of carbon dioxide that can be dissolved in the lean liquid 104b varies according to the pressure (partial pressure) according to Henry's law. When the pressure regulator 120 is decompressed by the decompression pump 124, the carbon dioxide gas 102d is released from the lean liquid 104b. Therefore, when the pressure regulator 120 is decompressed by the decompression pump 124, the amount of carbon dioxide in the lean liquid 104c discharged from the pressure regulator 120 is the amount of carbon dioxide in the lean liquid 104b discharged from the regeneration tower 105. Less.

  The valve 121 adjusts the flow rate of the lean liquid 104 b supplied to the pressure regulator 120. Further, the valve 122 adjusts the flow rate of the lean liquid 104 c discharged from the pressure regulator 120.

  The carbon dioxide gas 102d released from the lean liquid 104b in the pressure regulator 120 is cooled by the gas cooler 116 together with the exhaust gas 102c containing the carbon dioxide gas and steam discharged from the regeneration tower 105, and in the condenser 117, Separated into carbon dioxide gas and condensate. The carbon dioxide gas 102e discharged from the condenser 117 is stored in a storage facility (not shown). The condensate from the condenser 117 is supplied to the upper part of the regeneration tower 105.

  Between the absorption tower 103 and the regeneration tower 105, the lean liquid (lean liquid 104c discharged from the pressure regulator 120) supplied from the regeneration tower 105 to the absorption tower 103 is used as a heat source to transfer the absorption tower 103 to the regeneration tower 105. A regenerative heat exchanger 107 that heats the supplied rich liquid 104a is provided, and is configured to recover the heat of the lean liquid 104c.

  The lean liquid 104c from the regenerative heat exchanger 107 is cooled by the absorption liquid cooler 114. A part of the lean liquid 104 c cooled by the absorbing liquid cooler 114 is supplied to the ion exchange unit 130 via the valve 131.

  The ion exchange unit 130 is filled with an ion exchange resin so that the inorganic acid (inorganic acid ion) and the organic acid (organic acid ion) in the lean liquid 104c are removed. The inorganic acid is, for example, sulfuric acid or nitric acid, and the organic acid is, for example, formic acid or acetic acid. The lean liquid 104 d discharged from the ion exchange unit 130 merges with the lean liquid 104 c that has not been supplied to the ion exchange unit 130, and is supplied to the absorption tower 103. The lean liquid 104d may be directly supplied to the absorption tower 103.

  The lean liquid supplied to the absorption tower 103 descends toward the absorption tower tank 103a in the absorption tower 103. On the other hand, the flue gas 102 a supplied to the absorption tower 103 rises from the lower part toward the top in the absorption tower 103. Therefore, the combustion exhaust gas 102a containing carbon dioxide and the lean liquid are in countercurrent contact (direct contact) in the packed bed, carbon dioxide is removed from the combustion exhaust gas 102a and absorbed by the lean liquid, and the rich liquid 104a is generated. The combustion exhaust gas 102b from which carbon dioxide has been removed is discharged from the top of the absorption tower 103, and the rich liquid 104a is stored in the absorption tower tank 103a of the absorption tower 103.

  In addition, a measurement unit (not shown) that measures the accumulated amount (content) of the organic acid in the absorption liquid circulating through the carbon dioxide recovery device 100 is provided. For example, the measurement unit measures the accumulated amount (content) of the organic acid in the lean liquid 104d discharged from the ion exchange unit 130.

  In order to completely expel carbon dioxide from the absorption liquid in the regeneration tower 105, a large amount of heat energy supplied from the reboiler 106 is required, and the required energy per recovered carbon dioxide amount increases, so carbon dioxide is contained in the lean liquid 104b. Is operated with some remaining. The amount of carbon dioxide in the lean liquid 104b varies depending on the composition of the combustion exhaust gas 102a supplied to the absorption tower 102a and the amount of heat supplied to the reboiler 106.

  In the ion exchange unit 103, carbon dioxide is also removed as carbonate ions together with inorganic acid and organic acid. However, since the ion selectivity in the ion exchange unit 103 is inorganic acid ion> carbonate ion ≧ organic acid ion, carbon dioxide is When a large amount exists, carbon dioxide is preferentially adsorbed on the ion exchange resin over the organic acid, and the organic acid leaks without being treated. Due to the leakage of the organic acid, the accumulation amount (content) of the organic acid in the absorption liquid circulating through the carbon dioxide recovery device 100 changes.

  The carbon dioxide recovery device 100 includes a control unit that controls the opening degree of the valves 121 to 123 and 131 and the operation control of the decompression pump 124 based on the accumulated amount of the organic acid in the absorption liquid measured by the measurement unit. It may be.

  Next, the operation method of the pressure regulator 120 and the ion exchange part 130 is demonstrated. The operation method of the pressure regulator 120 and the ion exchange unit 130 differs depending on whether or not the accumulated amount of organic acid in the absorbent is equal to or greater than a predetermined value.

  When the accumulated amount of the organic acid in the absorption liquid is less than the predetermined value, the pressure regulator 120 is not depressurized, and a part of the lean liquid 104c is supplied to the ion exchange unit 130 to remove the organic acid and the inorganic acid. .

  On the other hand, when the accumulated amount of the organic acid in the absorption liquid is equal to or greater than the predetermined value, the amount of carbon dioxide in the lean liquid 104b increases, and the carbon dioxide is preferentially adsorbed on the ion exchange resin over the organic acid in the ion exchange unit 130. However, it is thought that the organic acid leaks without being treated. Therefore, when the accumulation amount of the organic acid in the absorption liquid becomes a predetermined value or more, the valve 131 is closed and the supply of the lean liquid 104 to the ion exchange unit 130 is stopped. Then, an alkaline solution is supplied to the ion exchange unit 130 to regenerate the ion exchange resin. Thereafter, the valve 131 is opened, and the pressure of the pressure regulator 120 is reduced by the decompression pump 124 to release the carbon dioxide gas 102d from the lean liquid 104b, and the carbon dioxide amount of the lean liquid 104c is made larger than the carbon dioxide amount of the lean liquid 104b. Reduce. Since the lean liquid 104c in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120 is supplied to the ion exchange unit 130, the organic acid can be efficiently removed.

  Thereafter, when the accumulated amount of the organic acid in the absorbing liquid becomes less than a predetermined value, the pressure reducing operation in the pressure regulator 120 may be stopped.

  Thus, since the amount of carbon dioxide in the lean liquid can be reduced by reducing the pressure of the pressure regulator 120, an increase in thermal energy supplied from the reboiler 106 can be suppressed. In addition, by supplying the lean liquid 104c, in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120, to the ion exchange unit 130, the ion exchange unit 130 is not enlarged and the ion exchange resin is not frequently regenerated. The organic acid can be efficiently removed by the ion exchange unit 130.

  Therefore, according to the carbon dioxide recovery apparatus 100 according to the present embodiment, while suppressing an increase in the size of the ion exchange tower, the regeneration frequency of the ion exchange resin, and the thermal energy supplied to the regeneration tower, the inorganic in the absorption liquid Acids and organic acids can be removed efficiently.

  In the above embodiment, a part of the lean liquid 104 c cooled by the absorption liquid cooler 114 is supplied to the ion exchange unit 130, but the ion exchange unit 130 is a rich liquid discharged from the absorption tower 103. The structure may be such that inorganic acid ions and organic acid ions are removed from 104a.

  In addition, a supply unit that supplies an alkaline solution for regenerating the ion exchange resin filled in the ion exchange unit 130, a washing water supply unit, a waste liquid extraction unit, and the like are connected to the ion exchange unit 130. Good.

  (Second Embodiment) FIG. 2 shows a schematic configuration of a carbon dioxide recovery apparatus according to a second embodiment of the present invention. This embodiment differs in the installation location of the pressure regulator 120 compared with 1st Embodiment shown in FIG. In FIG. 2, the same parts as those of the first embodiment shown in FIG.

  As shown in FIG. 2, a part of the lean liquid 104 b cooled by the absorbing liquid cooler 114 is supplied to the pressure regulator 120 via the valve 121. The lean liquid 104 c discharged from the pressure regulator 120 is supplied to the ion exchange unit 130 via the valve 122. The lean liquid 104 d discharged from the ion exchange unit 130 merges with the lean liquid 104 b that has not been supplied to the pressure regulator 120, and is supplied to the absorption tower 103.

  Next, the operation method of the pressure regulator 120 and the ion exchange part 130 is demonstrated. The operation method of the pressure regulator 120 and the ion exchange unit 130 differs depending on whether or not the accumulated amount of organic acid in the absorbent is equal to or greater than a predetermined value.

  When the accumulation amount of the organic acid in the absorption liquid is less than the predetermined value, the pressure regulator 120 is not depressurized and the lean liquid 104c is supplied to the ion exchange unit 130 to remove the organic acid and the inorganic acid.

  On the other hand, when the accumulated amount of the organic acid in the absorption liquid is equal to or greater than the predetermined value, the amount of carbon dioxide in the lean liquid 104b increases, and the carbon dioxide is preferentially adsorbed on the ion exchange resin over the organic acid in the ion exchange unit 130. It is considered that the organic acid leaks without being treated. Therefore, when the accumulation amount of the organic acid in the absorption liquid becomes a predetermined value or more, the valve 122 is closed and the supply of the lean liquid 104c to the ion exchange unit 130 is stopped. Then, an alkaline solution is supplied to the ion exchange unit 130 to regenerate the ion exchange resin. Thereafter, the valve 122 is opened, and the pressure of the pressure regulator 120 is reduced by the decompression pump 124 to release the carbon dioxide gas 102d from the lean liquid 104b. The carbon dioxide amount of the lean liquid 104c is set to be greater than the carbon dioxide amount of the lean liquid 104b. Reduce. Since the lean liquid 104c in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120 is supplied to the ion exchange unit 130, the organic acid can be efficiently removed.

  Thereafter, when the accumulated amount of the organic acid in the absorbing liquid becomes less than a predetermined value, the pressure reducing operation in the pressure regulator 120 may be stopped.

  Thus, since the amount of carbon dioxide in the lean liquid can be reduced by reducing the pressure of the pressure regulator 120, an increase in thermal energy supplied from the reboiler 106 can be suppressed. In addition, by supplying the lean liquid 104c, in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120, to the ion exchange unit 130, the ion exchange unit 130 is not enlarged and the ion exchange resin is not frequently regenerated. The organic acid can be efficiently removed by the ion exchange unit 130.

  Therefore, according to the carbon dioxide recovery apparatus 100 according to the present embodiment, while suppressing an increase in the size of the ion exchange tower, the regeneration frequency of the ion exchange resin, and the thermal energy supplied to the regeneration tower, the inorganic in the absorption liquid Acids and organic acids can be removed efficiently.

  In the first embodiment, since all the lean liquid 104b passes through the pressure regulator 120, when the pressure regulator 120 performs a decompression operation, the temperature of the lean liquid 104c is lower than the temperature of the lean liquid 104b due to the decompression. The amount of heat that can be recovered in the regenerative heat exchanger 107 by the rich liquid 104a has decreased. However, in this embodiment, since the pressure regulator 120 is provided on the downstream side of the regeneration heat exchanger 107, even when the pressure regulator 120 performs a pressure reduction operation, the recovery of the rich liquid 104a in the regeneration heat exchanger 107 is performed. A decrease in the amount of heat can be prevented.

  (Third Embodiment) FIG. 3 shows a schematic configuration of a carbon dioxide recovery apparatus according to a third embodiment of the present invention. In the present embodiment, as compared with the first embodiment shown in FIG. 1, the lean liquid 104 b discharged from the regeneration tower 105 is divided, one is supplied to the pressure regulator 120, and the other is the regeneration heat exchanger. The difference is that it is supplied to 107. Another difference is that the lean liquid 104c discharged from the pressure regulator 120 is cooled by the absorption liquid cooler 140 and directly supplied to the ion exchange unit 130. In FIG. 3, the same parts as those of the first embodiment shown in FIG.

  As shown in FIG. 3, the lean liquid 104 b discharged from the regeneration tower 105 is diverted, and one is supplied to the pressure regulator 120 via the valve 121, and the other is supplied to the regeneration heat exchanger 107. The lean liquid 104c discharged from the pressure regulator 120 is supplied to the ion exchange unit 130 via the valve 122 and the absorption liquid cooler 140.

  The lean liquid 104b from the regenerative heat exchanger 107 is cooled by the absorption liquid cooler 114. A part of the lean liquid 104b cooled by the absorbing liquid cooler 114 is supplied to the ion exchange unit 130 via the valve 131.

  The lean solution 104 d discharged from the ion exchange unit 130 merges with the lean solution 104 b that has not been supplied to the ion exchange unit 130, and is supplied to the absorption tower 103.

  Next, the operation method of the pressure regulator 120 and the ion exchange part 130 is demonstrated. The operation method of the pressure regulator 120 and the ion exchange unit 130 differs depending on whether or not the accumulated amount of organic acid in the absorbent is equal to or greater than a predetermined value.

  When the accumulated amount of organic acid in the absorbing liquid is less than a predetermined value, the valve 121 is closed and the pressure regulator 120 is not depressurized, and all the lean liquid 104b is supplied to the regenerative heat exchanger 107. The ion exchange unit 130 is supplied with a part of the lean liquid 104b and removes organic acids and inorganic acids.

  On the other hand, when the accumulated amount of the organic acid in the absorption liquid is equal to or greater than the predetermined value, the amount of carbon dioxide in the lean liquid 104b increases, and the carbon dioxide is preferentially adsorbed on the ion exchange resin over the organic acid in the ion exchange unit 130. It is considered that the organic acid leaks without being treated. Therefore, when the accumulation amount of the organic acid in the absorption liquid becomes a predetermined value or more, the valve 131 is closed and the supply of the lean liquid 104b to the ion exchange unit 130 is stopped. Then, an alkaline solution is supplied to the ion exchange unit 130 to regenerate the ion exchange resin. Thereafter, the valve 121 is opened, a part of the lean liquid 104 b is diverted and supplied to the pressure regulator 120, and the pressure of the pressure regulator 120 is reduced by the decompression pump 124. As a result, the carbon dioxide gas 102d is released from the lean liquid 104b, and the amount of carbon dioxide in the lean liquid 104c is smaller than the amount of carbon dioxide in the lean liquid 104b. Since the lean liquid 104c in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120 is supplied to the ion exchange unit 130, the organic acid can be efficiently removed.

  Thereafter, when the accumulated amount of the organic acid in the absorbing liquid becomes less than a predetermined value, the pressure reducing operation in the pressure regulator 120 may be stopped.

  Thus, since the amount of carbon dioxide in the lean liquid can be reduced by reducing the pressure of the pressure regulator 120, an increase in thermal energy from the reboiler 106 can be suppressed. In addition, by supplying the lean liquid 104c, in which the amount of carbon dioxide is reduced by the pressure reduction of the pressure regulator 120, to the ion exchange unit 130, the ion exchange unit 130 is not enlarged and the ion exchange resin is not frequently regenerated. The organic acid can be efficiently removed by the ion exchange unit 130.

  Therefore, according to the carbon dioxide recovery apparatus 100 according to the present embodiment, while suppressing an increase in the size of the ion exchange tower, the regeneration frequency of the ion exchange resin, and the thermal energy supplied to the regeneration tower, the inorganic in the absorption liquid Acids and organic acids can be removed efficiently.

  In the first embodiment, since all the lean liquid 104b passes through the pressure regulator 120, when the pressure regulator 120 performs a decompression operation, the temperature of the lean liquid 104c is lower than the temperature of the lean liquid 104b due to the decompression. The amount of heat that can be recovered in the regenerative heat exchanger 107 by the rich liquid 104a has decreased. However, in this embodiment, the lean liquid 104b is divided and supplied to each of the regenerative heat exchanger 107 and the pressure regulator 120. Therefore, even when the pressure regulator 120 performs a decompression operation, the regenerative heat exchanger It is possible to prevent the temperature of the lean liquid supplied to 107 from being lowered.

  In addition, the configuration of the present embodiment can be realized by additionally installing the pressure regulator 120 and the ion exchange unit 130 in the existing carbon dioxide recovery device.

  As shown in FIG. 4, a regenerative heat exchanger 108 for heating the rich liquid 104a discharged from the absorption tower 103 is provided using the lean liquid 104c discharged from the pressure regulator 120 as a heat source, and the heat of the lean liquid 104c is recovered. You may make it do. Since the lean liquid 104c has a lower temperature than the lean liquid 104b, the regenerative heat exchanger 108 is provided on the upstream side of the rich liquid 104a flow path with respect to the regenerative heat exchanger 107.

  In the first to third embodiments, a line may be provided in which the lean liquid 104d discharged from the ion exchange unit 130 is supplied to the ion exchange unit 130 again. As a result, the lean liquid passes through the ion exchange unit 130 a plurality of times, and the organic acid can be more effectively removed.

  According to the carbon dioxide recovery apparatus and method of at least one embodiment described above, absorption is suppressed while suppressing an increase in the size of the ion exchange tower, the frequency of regeneration of the ion exchange resin, and the thermal energy supplied to the regeneration tower. The inorganic acid and organic acid in the liquid can be efficiently removed.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 Carbon dioxide recovery device 103 Absorption tower 105 Regeneration tower 106 Reboiler 107 Regeneration heat exchanger 117 Condenser 120 Pressure regulator 130 Ion exchange part

Claims (10)

An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the absorption liquid containing carbon dioxide;
An absorption liquid discharged from the absorption tower is supplied, a carbon dioxide gas containing steam is removed from the absorption liquid, and a regeneration tower that regenerates and discharges the absorption liquid;
A pressure regulator for depressurizing at least part of the absorbent discharged from the regeneration tower and releasing carbon dioxide gas from the absorbent;
An ion exchange unit that is supplied with an absorption liquid from which carbon dioxide gas is released by the pressure regulator, removes inorganic acid ions and organic acid ions from the absorption liquid, and supplies the absorption tower to the absorption tower;
Absorbing liquid provided between the absorption tower and the regeneration tower, discharged from the regeneration tower and supplied to the absorption tower as a heat source, and discharged from the absorption tower and supplied to the regeneration tower A regenerative heat exchanger that heats ,
With
The absorption liquid discharged from the regeneration tower is supplied to the pressure regulator, the absorption liquid discharged from the pressure regulator is supplied to the regeneration heat exchanger, and the absorption liquid after passing through the regeneration heat exchanger partially Ru is supplied to the ion-exchange unit carbon dioxide recovery apparatus. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the absorption liquid containing carbon dioxide;
An absorption liquid discharged from the absorption tower is supplied, a carbon dioxide gas containing steam is removed from the absorption liquid, and a regeneration tower that regenerates and discharges the absorption liquid;
A pressure regulator for depressurizing at least part of the absorbent discharged from the regeneration tower and releasing carbon dioxide gas from the absorbent;
An ion exchange unit that is supplied with an absorption liquid from which carbon dioxide gas is released by the pressure regulator, removes inorganic acid ions and organic acid ions from the absorption liquid, and supplies the absorption tower to the absorption tower;
Absorbing liquid provided between the absorption tower and the regeneration tower, discharged from the regeneration tower and supplied to the absorption tower as a heat source, and discharged from the absorption tower and supplied to the regeneration tower A regenerative heat exchanger that heats ,
With
Absorption liquid discharged from the regeneration tower is supplied to the regeneration heat exchanger, and a part of the absorption liquid after passing through the regeneration heat exchanger is supplied to the pressure regulator and discharged from the pressure regulator. absorbing liquid Ru is supplied to the ion-exchange unit carbon dioxide recovery apparatus. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the absorption liquid containing carbon dioxide;
An absorption liquid discharged from the absorption tower is supplied, a carbon dioxide gas containing steam is removed from the absorption liquid, and a regeneration tower that regenerates and discharges the absorption liquid;
A pressure regulator for depressurizing at least part of the absorbent discharged from the regeneration tower and releasing carbon dioxide gas from the absorbent;
An ion exchange unit that is supplied with an absorption liquid from which carbon dioxide gas is released by the pressure regulator, removes inorganic acid ions and organic acid ions from the absorption liquid, and supplies the absorption tower to the absorption tower;
Absorbing liquid provided between the absorption tower and the regeneration tower, discharged from the regeneration tower and supplied to the absorption tower as a heat source, and discharged from the absorption tower and supplied to the regeneration tower A regenerative heat exchanger that heats ,
With
Absorbing liquid discharged from the regeneration tower is divided, one is supplied to the pressure regulator, the other is supplied to the regeneration heat exchanger, and the absorbing liquid discharged from the pressure regulator and the regeneration heat exchanger passage after absorption liquid part of which Ru carbon dioxide recovery apparatus is supplied to the ion exchange unit. The regenerative heat exchanger is provided between the absorption tower and the regenerative heat exchanger, and is discharged from the absorption tower using the absorption liquid discharged from the pressure regulator and supplied to the ion exchange section as a heat source. The carbon dioxide recovery apparatus according to claim 3 , further comprising a second regenerative heat exchanger that heats the absorption liquid supplied to the tank. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the absorption liquid containing carbon dioxide;
An absorption liquid discharged from the absorption tower is supplied, a carbon dioxide gas containing steam is removed from the absorption liquid, and a regeneration tower that regenerates and discharges the absorption liquid;
A pressure regulator for depressurizing at least part of the absorbent discharged from the regeneration tower and releasing carbon dioxide gas from the absorbent;
An ion exchange unit that is supplied with an absorption liquid from which carbon dioxide gas is released by the pressure regulator, removes inorganic acid ions and organic acid ions from the absorption liquid, and supplies the absorption tower to the absorption tower;
With
The carbon dioxide gas released from the pressure regulator, the regeneration-absorbing liquid carbon dioxide removed from the to that carbon dioxide recovery device merge at. An absorption tower for absorbing carbon dioxide contained in the combustion exhaust gas into the absorption liquid and discharging the absorption liquid containing carbon dioxide;
An absorption liquid discharged from the absorption tower is supplied, a carbon dioxide gas containing steam is removed from the absorption liquid, and a regeneration tower that regenerates and discharges the absorption liquid;
A pressure regulator for depressurizing at least part of the absorbent discharged from the regeneration tower and releasing carbon dioxide gas from the absorbent;
An ion exchange unit that is supplied with an absorption liquid from which carbon dioxide gas is released by the pressure regulator, removes inorganic acid ions and organic acid ions from the absorption liquid, and supplies the absorption tower to the absorption tower;
A measuring unit for measuring the content of the organic acid in the circulating absorption liquid;
When the content measured by the measurement unit is a predetermined value or more, a control unit that depressurizes the pressure regulator and releases carbon dioxide gas from the absorption liquid;
Ru with a carbon dioxide recovery apparatus. In the absorption tower, the step of causing the absorption liquid to absorb carbon dioxide contained in the combustion exhaust gas and discharging the absorption liquid containing carbon dioxide;
In the regeneration tower, removing carbon dioxide gas containing steam from the absorption liquid discharged from the absorption tower, regenerating and discharging the absorption liquid;
A step of removing inorganic acid ions and organic acid ions from a part of the absorption liquid discharged from the regeneration tower and supplied to the absorption tower by an ion exchange section;
Measuring the organic acid content in the circulating absorbent,
When the content is equal to or greater than a predetermined value, the pressure regulator depressurizes at least part of the absorbing liquid discharged from the regeneration tower to release carbon dioxide gas from the absorbing liquid;
Supplying the absorption liquid discharged from the pressure regulator to the ion exchange unit, and removing inorganic acid ions and organic acid ions;
A carbon dioxide recovery method comprising: In the absorption tower, the step of causing the absorption liquid to absorb carbon dioxide contained in the combustion exhaust gas and discharging the absorption liquid containing carbon dioxide;
In the regeneration tower, removing carbon dioxide gas containing steam from the absorption liquid discharged from the absorption tower, regenerating and discharging the absorption liquid;
A step of depressurizing at least part of the absorption liquid discharged from the regeneration tower by a pressure regulator to release carbon dioxide gas from the absorption liquid;
A step of removing inorganic acid ions and organic acid ions from the absorbing liquid from which carbon dioxide gas has been released by the pressure regulator by an ion exchange unit;
The step of heating the absorption liquid discharged from the absorption tower and supplied to the regeneration tower by using the absorption liquid discharged from the regeneration tower and supplied to the absorption tower as a heat source by the regeneration heat exchanger;
With
The absorption liquid discharged from the regeneration tower is supplied to the pressure regulator, the absorption liquid discharged from the pressure regulator is supplied to the regeneration heat exchanger, and the absorption liquid after passing through the regeneration heat exchanger A carbon dioxide recovery method in which a part is supplied to the ion exchange section. In the absorption tower, the step of causing the absorption liquid to absorb carbon dioxide contained in the combustion exhaust gas and discharging the absorption liquid containing carbon dioxide;
In the regeneration tower, removing carbon dioxide gas containing steam from the absorption liquid discharged from the absorption tower, regenerating and discharging the absorption liquid;
A step of depressurizing at least part of the absorption liquid discharged from the regeneration tower by a pressure regulator to release carbon dioxide gas from the absorption liquid;
A step of removing inorganic acid ions and organic acid ions from the absorbing liquid from which carbon dioxide gas has been released by the pressure regulator by an ion exchange unit;
The step of heating the absorption liquid discharged from the absorption tower and supplied to the regeneration tower by using the absorption liquid discharged from the regeneration tower and supplied to the absorption tower as a heat source by the regeneration heat exchanger;
With
Absorption liquid discharged from the regeneration tower is supplied to the regeneration heat exchanger, and a part of the absorption liquid after passing through the regeneration heat exchanger is supplied to the pressure regulator and discharged from the pressure regulator. A carbon dioxide recovery method in which an absorbing solution is supplied to the ion exchange unit. In the absorption tower, the step of causing the absorption liquid to absorb carbon dioxide contained in the combustion exhaust gas and discharging the absorption liquid containing carbon dioxide;
In the regeneration tower, removing carbon dioxide gas containing steam from the absorption liquid discharged from the absorption tower, regenerating and discharging the absorption liquid;
A step of depressurizing at least part of the absorption liquid discharged from the regeneration tower by a pressure regulator to release carbon dioxide gas from the absorption liquid;
A step of removing inorganic acid ions and organic acid ions from the absorbing liquid from which carbon dioxide gas has been released by the pressure regulator by an ion exchange unit;
The step of heating the absorption liquid discharged from the absorption tower and supplied to the regeneration tower by using the absorption liquid discharged from the regeneration tower and supplied to the absorption tower as a heat source by the regeneration heat exchanger;
With
Absorbing liquid discharged from the regeneration tower is divided, one is supplied to the pressure regulator, the other is supplied to the regeneration heat exchanger, and the absorbing liquid discharged from the pressure regulator and the regeneration heat exchanger A carbon dioxide recovery method in which a part of the absorption liquid after passing through is supplied to the ion exchange section.

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