KR20230061104A - Exhaust gas treatment device - Google Patents

Abstract

An exhaust gas treatment device is provided according to an embodiment of the present invention.
An exhaust gas treatment device according to an embodiment of the present invention includes an exhaust pipe for discharging exhaust gas generated from a combustion engine, and a carbon dioxide collecting device installed on the exhaust pipe to remove carbon dioxide included in the exhaust gas, and The device includes an absorption tower that injects an absorbent for absorbing carbon dioxide into exhaust gas, a regeneration tower that separates carbon dioxide from the absorbent by heating the absorbent absorbed with carbon dioxide supplied from the absorption tower, and a connection between the absorption tower and the regeneration tower. , Installed on a first flow pipe for supplying the absorbent from which carbon dioxide has been absorbed to the regeneration tower, a second flow pipe connecting the regeneration tower and the absorption tower to circulate the absorbent from which carbon dioxide is separated to the absorption tower, and the second flow pipe, , a by-product separation unit for separating by-products generated by the decomposition of the absorbent heated in the regeneration tower from the absorbent.

Description

Exhaust gas treatment device {Exhaust gas treatment device}

The present invention relates to an exhaust gas treatment device, and more particularly, to an exhaust gas treatment capable of preventing a decrease in carbon dioxide capture efficiency by separating by-products generated by the decomposition of an absorbent that absorbs carbon dioxide contained in exhaust gas from the absorbent. It's about the device.

In general, various engines installed in ships generate power by burning fuel, and exhaust gas generated in the process of burning fuel includes nitrogen oxides (NOx), sulfur oxides (SOx), carbon dioxide, and the like. As air pollution increases, regulations on various harmful substances included in exhaust gas are becoming stricter, and not only nitrogen oxides and sulfur oxides but also carbon dioxide are subject to emission regulations from the International Maritime Organization (IMO), an oxidation agency of the United Nations. are receiving

Methods for capturing carbon dioxide contained in exhaust gas include a wet capturing method using an absorbent and a dry capturing method using a membrane. Among them, the wet capture method passes the exhaust gas through an absorption tower in which an absorbent is present, absorbs carbon dioxide contained in the exhaust gas into the absorbent, and passes the absorbent that has absorbed the carbon dioxide through a regeneration tower to separate the carbon dioxide and the absorbent. As such, it is usually used on ships.

Meanwhile, the regeneration tower separates the carbon dioxide and the absorbent by heating the absorbent in which the carbon dioxide is absorbed. At this time, as a part of the absorbent is decomposed, by-products including nitrogen may be formed. By-products produced by the decomposition of the absorbent not only reduce the purity of the absorbent and reduce carbon dioxide capture efficiency, but also cause air pollution by being discharged to the top of the absorption tower together with the exhaust gas.

Accordingly, there is a need for an exhaust gas treatment device including a carbon dioxide collecting device having a structure capable of separating by-products generated by the decomposition of the absorbent from the absorbent.

Republic of Korea Patent Publication No. 10-2010-0124547 (2010. 11. 29.)

A technical problem to be achieved by the present invention is to provide an exhaust gas treatment device capable of preventing carbon dioxide capture efficiency from deteriorating by separating by-products generated by the decomposition of an absorbent for absorbing carbon dioxide contained in exhaust gas from the absorbent.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

An exhaust gas treatment device according to an embodiment of the present invention for achieving the above technical problem is an exhaust pipe for discharging exhaust gas generated from a combustion engine, and carbon dioxide installed on the exhaust pipe to remove carbon dioxide contained in the exhaust gas. Including a capture device, wherein the carbon dioxide capture device includes an absorption tower for injecting an absorbent for absorbing carbon dioxide into the exhaust gas, and separating carbon dioxide from the absorbent by heating the absorbent in which carbon dioxide supplied from the absorption tower is absorbed. A regeneration tower, a first flow pipe connected between the absorption tower and the regeneration tower to supply the absorbent in which carbon dioxide has been absorbed to the regeneration tower, and a first flow pipe connected between the regeneration tower and the absorption tower so that carbon dioxide is separated A second flow pipe circulating the absorbent to the absorption tower, and a by-product separation unit installed on the second flow pipe and separating by-products generated by decomposition of the absorbent heated in the regeneration tower from the absorbent.

The by-product separation unit may include an ion exchange resin for chemically adsorbing the by-product, and a chamber accommodating the ion exchange resin.

The by-product separation unit includes a plurality of anion exchange resins for adsorbing nitrite ions (NO ₂ ^- ) and nitrate ions (NO ₃ ^- ), which are anions among the by-products, and a first chamber accommodating the anion exchange resins. _A front end of the first ^separation unit or It may include a second separation unit disposed at the rear end.

The exhaust gas treatment device may further include an ion water supply pipe supplying ion water to the by-product separation unit to desorb the by-product adsorbed on the ion exchange resin.

As the anion contained in the ionized water is adsorbed to the anion exchange resin, the nitrite ion and the nitrate ion are desorbed from the anion exchange resin, and the cation contained in the ionized water is adsorbed to the cation exchange resin, and the ammonium ion is absorbed into the cation exchange resin. It can be separated from the exchange resin.

A plurality of the by-product separation units may be installed in parallel and driven selectively.

The exhaust gas treatment device is installed in the second flow pipe at the rear of the by-product separation unit to measure the nitrogen ion concentration of the absorbent circulated to the absorption tower, or is installed in the exhaust pipe at the rear of the absorption tower to obtain Further comprising a sensor unit for measuring the nitrogen ion concentration of the discharged exhaust gas, wherein the by-product separation unit operates when the nitrogen ion concentration of the absorbent or the nitrogen ion concentration of the exhaust gas measured by the sensor unit is greater than or equal to a reference value. The by-product can be adsorbed.

According to the present invention, by-products generated by the decomposition of the absorbent are separated from the absorbent by using the chemical adsorption properties of the ion exchange resin, so that the purity of the absorbent can be maintained. Therefore, it is possible to prevent the carbon dioxide capture efficiency of the carbon dioxide capture device from deteriorating, and also to prevent by-products from being discharged together with the exhaust gas to the top of the absorption tower to cause air pollution.

In addition, since by-products are desorbed when ion water is supplied to the ion exchange resin adsorbed with by-products, it is possible to use them semi-permanently, thereby reducing equipment operating costs.

1 is a diagram showing an exhaust gas treatment device according to an embodiment of the present invention.
2 is an enlarged view of a by-product separation unit.
3 is a view for explaining a process in which by-products are adsorbed and desorbed in the by-product separation unit.
4 and 5 are operation diagrams for explaining the operation of the exhaust gas treatment device.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Hereinafter, with reference to FIGS. 1 to 5, an exhaust gas treatment device according to an embodiment of the present invention will be described in detail.

An exhaust gas treatment device according to an embodiment of the present invention is a device for removing carbon dioxide included in exhaust gas generated from a combustion engine, and may be applied to ships.

Exhaust gas treatment device By-products generated by the decomposition of the absorbent are separated from the absorbent by using the chemical adsorption properties of the ion exchange resin, so that the purity of the absorbent can be maintained. Therefore, it is possible to prevent the carbon dioxide capture efficiency of the carbon dioxide capture device from deteriorating, and also to prevent by-products from being discharged together with the exhaust gas to the top of the absorption tower to cause air pollution. In addition, since the by-products are desorbed when ionized water is supplied to the ion exchange resin adsorbed with the by-products, it is possible to use them semi-permanently, thereby reducing the operating cost of the device.

Hereinafter, with reference to FIGS. 1 to 3, the exhaust gas treatment device 1 will be described in detail.

1 is a diagram showing an exhaust gas treatment device according to an embodiment of the present invention, FIG. 2 is an enlarged view of a by-product separation unit, and FIG. 3 describes a process in which by-products are adsorbed and desorbed in the by-product separation unit. It is a drawing for

An exhaust gas treatment device 1 according to the present invention includes an exhaust pipe 10 and a carbon dioxide capture device 20, and the carbon dioxide capture device 20 includes an absorption tower 21, a regeneration tower 22, a first flow pipe ( 23), a second flow pipe 24, and by-product separation units 25 and 25'.

The exhaust pipe 10 is a pipe for discharging the exhaust gas generated from the combustion engine 100, and on the exhaust pipe 10, a wet scrubber (not shown) for removing sulfur oxides and a selective catalytic reduction reactor (shown) for removing nitrogen oxides not), at least one of the economizers 12 that recover heat may be installed. Hereinafter, the structure in which the economizer 12 is installed on the exhaust pipe 10 will be more intensively described. A branch pipe 11a is branched on the exhaust pipe 10 at the rear end of the economizer 12, and the branch pipe 11a may be connected to the carbon dioxide capture device 20 that removes carbon dioxide included in the exhaust gas. At this time, the flow of the exhaust gas discharged to the atmosphere through the exhaust pipe 10 and the flow of the exhaust gas supplied to the carbon dioxide capture device 20 through the branch pipe 11a are controlled at the branching point of the branch pipe 11a. A control valve 11 in the form of a three-phase valve for controlling may be installed. However, it is not limited to that the control valve 11 in the form of a three-phase valve is installed at the branching point of the branch pipe 11a, and the flow of exhaust gas is controlled in the exhaust pipe 10 and the branch pipe 11a, respectively, as necessary. A control valve for controlling may be installed. The exhaust gas diverged to the branch pipe 11a is cooled to an appropriate temperature through heat exchange with the cooling water in the cooling tower 13, and the cooling water whose temperature has increased by heat exchange with the exhaust gas is discharged from the cooling tower 13 and then undergoes a series of cooling processes. After passing through, it can be circulated back to the cooling tower (13). The exhaust gas cooled in the cooling tower 13 is supplied to the absorption tower 21 after moisture is removed.

The absorption tower 21 atomizes or atomizes an absorbent for absorbing carbon dioxide into the exhaust gas supplied from the cooling tower 13 and sprays it. It may be a solution with properties, for example, an amine compound such as mono ethanol amine. The exhaust gas is supplied to the lower part of the absorption tower 21 and comes into contact with the absorbent sprayed from the upper part of the absorption tower 21, whereby carbon dioxide contained in the exhaust gas is absorbed by the absorbent and can be removed from the exhaust gas. The exhaust gas from which carbon dioxide has been removed may be exhausted to the outside through the branch pipe 11a connected to the top of the absorption tower 21 or rejoined to the exhaust pipe 10. Since an exothermic reaction occurs when carbon dioxide is absorbed by the absorbent in the absorption tower 21, the exhaust gas from which carbon dioxide is removed is exhausted to the outside through a branch pipe 11a after undergoing a separate cooling process at the top of the absorption tower 21. or can be joined to the exhaust pipe (10). For example, the exhaust gas from which carbon dioxide has been removed may be discharged after being cooled in contact with a cooling medium such as fresh water sprayed from the top of the absorption tower 21, and the cooling medium in contact with the exhaust gas may be discharged outside the absorption tower 21. After being discharged to, it may be circulated back to the absorption tower 21 through a separate pressurization and cooling process. The absorbent that has absorbed carbon dioxide in the absorption tower 21 is supplied to the regeneration tower 22.

The regeneration tower 22 separates carbon dioxide from the absorbent by heating the absorbent in which the carbon dioxide supplied from the absorber 21 is absorbed. More specifically, the carbon dioxide absorbed absorbent is supplied to the top of the regeneration tower 22, and carbon dioxide can be separated by thermal energy while flowing from the top to the bottom of the regeneration tower 22. At this time, some of the absorbent inside the regeneration tower 22 flows into the reboiler 31 through the circulation line 30 and is heated, and carbon dioxide and steam generated from the absorbent by the heating of the reboiler 31 are removed from the circulation line. It is circulated to the regeneration tower 22 through (30) to provide additional thermal energy while increasing the efficiency of carbon dioxide separation. The high-concentration carbon dioxide separated from the absorbent is discharged to the upper part of the regeneration tower 22, passes through the condenser 221 and the reflux drum 222 in turn, removes moisture, and can be supplied to the required place through a separate compression process. Water separated from carbon dioxide in the reflux drum 222 may be pressurized and circulated back to the regeneration tower 22 . The regeneration tower 22 may receive the absorbent from which carbon dioxide is absorbed through the first flow pipe 23 and circulate the absorbent from which carbon dioxide is separated to the absorption tower 21 through the second flow pipe 24 to be described later.

The first flow pipe 23 connects the absorption tower 21 and the regeneration tower 22 to supply the absorbent in which carbon dioxide is absorbed to the regeneration tower 22 . More specifically, the first flow pipe 23 has one end connected to the lower part of the absorption tower 21 and the other end connected to the upper part of the regeneration tower 22, so that the absorbent that has absorbed the carbon dioxide discharged from the absorption tower 21 is transferred to the regeneration tower. (22) It can be fed from the top. At least one pump 23a for pressurizing the absorbent that has absorbed carbon dioxide and a heat exchanger 241 may be installed on the first flow pipe 23 .

The heat exchanger 241 heats the absorbent in which carbon dioxide supplied to the regeneration tower 22 is absorbed by exchanging heat between the first flow pipe 23 and the second flow pipe 24 . That is, the heat exchanger 241 includes the absorbent at about 40 to 50° C. supplied from the absorption tower 21 to the regeneration tower 22 through the first flow pipe 23, and the regeneration tower ( In 22), the absorbent at about 80 to 150° C. circulated to the absorption tower 21 is heat-exchanged to raise the temperature of the absorbent supplied to the regeneration tower 22 and lower the temperature of the absorbent circulated to the absorption tower 21. As the temperature of the absorbent supplied to the regeneration tower 22 increases, carbon dioxide can be separated more effectively in the regeneration tower 22, and as the temperature of the absorbent circulated to the absorption tower 21 decreases, the absorption tower 21 ), carbon dioxide can be more easily absorbed by the absorbent.

The second flow pipe 24 connects the regeneration tower 22 and the absorption tower 21 to circulate the absorbent from which carbon dioxide is separated to the absorption tower 21. More specifically, the second flow pipe 24 has one end connected to the lower part of the regeneration tower 22 and the other end connected to the upper part of the absorption tower 21, so that the carbon dioxide discharged from the regeneration tower 22 is separated and the absorbent is transferred to the absorption tower. (21) It can be fed from the top. Since the above-mentioned heat exchanger 241, pump 242, and cooler 243 are installed on the second flow pipe 24, about 80 to 150 ° C. discharged from the regeneration tower 22 to the second flow pipe 24 The absorbent from which carbon dioxide is separated may be cooled in multiple stages and supplied to the absorption tower 21 in a state of about 30 to 50 ° C.

As described above, the carbon dioxide absorbed absorbent supplied to the regeneration tower 22 is in a heated state in the heat exchanger 241, and the carbon dioxide and steam generated from the absorbent heated in the reboiler 31 provide additional thermal energy. Therefore, some of the absorbent may be thermally decomposed to form by-products. The by-product may be an ionized nitrogen compound, and more specifically, may include at least one of ammonium ion (NH ₃ ⁺ ), nitrite ion (NO ₂ ^- ), and nitrate ion (NO ₃ ^- ). These by-products decrease the purity of the absorbent, reduce the carbon dioxide capture efficiency of the absorber 21, and are discharged together with the exhaust gas through the branch pipe 11a to cause air pollution, so they need to be separated from the absorbent. By-products included in the absorbent may be separated in the by-product separation units 25 and 25'.

The by-product separation units 25 and 25' separate the by-products generated by the decomposition of the absorbent heated in the regeneration tower 22 from the absorbent, and the second flow pipe 24, more specifically, the second flow pipe 24, more specifically, the rear end of the cooler 243 2 can be installed on the flow pipe (24). The by-product separation units 25 and 25' may include ion exchange resins 251a and 251b for chemically adsorbing and separating by-products included in the absorbent and chambers 252a and 252b for accommodating the ion exchange resin. there is. That is, the by-product separation units 25 and 25' may have a plurality of plastic ball-shaped ion exchange resins 251a and 251b accommodated in the chambers 252a and 252b. By-product separation units 25 and 25' separate by-products from the absorbent using the chemical adsorption properties of the ion exchange resins 251a and 251b, so that the purity of the absorbent is maintained and the carbon dioxide capture efficiency of the absorption tower 21 is maintained. Air pollution can also be prevented.

Referring to FIG. 2 , the by-product separation units 25 and 25' include a first separation unit 25a and a second separation unit 25b disposed before or after the first separation unit 25a. Hereinafter, a structure in which the second separation unit 25b is disposed at the rear end of the first separation unit 25a will be more intensively described. The first separation unit 25a includes a plurality of anion exchange resins 251a for adsorbing nitrite ions (NO ₂ ^- ) and nitrate ions (NO ₃ ^- ), which are by-product anions, and a first separator for accommodating the anion exchange resins 251a. It may include one chamber (252a). The second separation unit 25b accommodates a plurality of cation exchange resins 251b for adsorbing ammonium ions (NH ₃ ⁺ ), which are cations among by-products, and the cation exchange resins 251b, and passes through the second flow pipe 24a. A second chamber 252b connected to the first chamber 252a may be included.

Referring to FIGS. 2 and 3 (a), the by-products (ammonium ion (NH ₃ ⁺ ), nitrite ion (NO ₂ ^- ), nitrate ion (NO ₃ ^- ) through the second flow pipe (24a) )) is supplied to the first chamber 252a of the first separation unit 25a, the anion exchange resin 251a in which nitrite ions (NO ₂ ^- ) and nitrate ions (NO ₃ ^- ) have the same polarity It is adsorbed and separated, and the chlorine ion (Cl ^- ) bonded to the surface of the anion exchange resin 251a may be desorbed. The desorbed chlorine ions (Cl ⁻ ) may move to the second separation unit 25b through the second flow pipe 24a together with the absorbent and ammonium ions (NH ₃ ⁺ ). When an absorbent containing chloride ions (Cl ^- ) and ammonium ions (NH ₃ ⁺ ) is supplied to the second chamber 252b, ammonium ions (NH ₃ ⁺ ) are adsorbed to and separated from the cation exchange resin 251b having the same polarity. and sodium ions (Na ⁺ ) bonded to the surface of the cation exchange resin 251b may be released. The desorbed sodium ions (Na ⁺ ) combine with chlorine ions (Cl ^- ) to produce sodium chloride (NaCl), and the generated sodium chloride (NaCl) is discharged through the discharge pipe 253b coupled to the bottom of the second chamber 252b. and may be separately stored or subjected to a separate processing process. The absorbent separated by adsorption of by-products on the ion exchange resins 251a and 251b may be circulated to the absorption tower 21 through the second flow pipe 24 and undergo the above-described series of processes.

A plurality of these by-product separation units 25 and 25' are installed in parallel and selectively driven, respectively, and the second flow pipes 24a and 24b are branched and connected to each of the by-product separation units 25 and 25'. If the by-product separation units 25 and 25' are used for a long time, the by-products are excessively adsorbed on the surfaces of the ion exchange resins 251a and 251b, and the adsorption capacity may decrease. Since a plurality of by-product separation units (25, 25') are connected in parallel and selectively driven, the adsorption process can be performed on some (25) and the regeneration process can be performed on the remaining part (25'), so that by-products can be continuously separated. can

The by-product separation unit 25 in which the adsorption capacity of the ion exchange resins 251a and 251b is reduced may receive ionized water from the ionized water supply pipe 26 . The ion water supply pipe 26 supplies ion water, for example, seawater, respectively to the plurality of by-product separation units 25 and 25' installed in parallel to desorb by-products adsorbed on the ion exchange resins 251a and 251b. 2 and 3 (b), when ionized water, that is, seawater, is supplied to the first chamber 252a of the first separation unit 25a through the ionized water supply pipe 26, the ionized water The included anion, that is, the chloride ion (Cl ^- ) of seawater (NaCl) is adsorbed to the anion exchange resin 251a, and thereby, the nitrite ion (NO ₂ ^- ) and nitric acid bound to the anion exchange resin 251a Ions (NO ₃ ^- ) may be desorbed from the anion exchange resin 251a. The desorbed nitrite ions (NO ₂ ^- ) and nitrate ions (NO ₃ ^- ) may move together with sodium ions (Na ⁺ ) to the second separation unit 25b through the second flow pipe 24a. When nitrite ions (NO ₂ ^- ), nitrate ions (NO ₃ ^- ), and sodium ions (Na ⁺ ) are supplied to the second chamber 252b, cations included in the ionized water, that is, sodium ions (Na ⁺ ) are cations Adsorbed on the exchange resin 251b, and as a result, ammonium ions (NH ₃ ⁺ ) bonded to the cation exchange resin 251b may be desorbed from the cation exchange resin 251b. Nitrite ions (NO ₂ ^- ), nitrate ions (NO ₃ ^- ), and ammonium ions (NH ₃ ⁺ ) desorbed through this series of processes are discharged through the discharge pipe 253b and stored separately or undergo a separate treatment process. can

These by-product separation units 25 and 25' may operate in conjunction with the sensor unit 27. The sensor unit 27 is installed in the second flow pipe 24 at the rear end of the by-product separation units 25 and 25' to measure the nitrogen ion concentration of the absorbent circulated to the absorption tower 21, or to measure the nitrogen ion concentration at the rear end of the absorption tower 21 It is installed in the exhaust pipe 10, that is, the branch pipe 11a connected to the upper end of the absorption tower 21, and the nitrogen ion concentration of the exhaust gas discharged from the absorption tower 21 can be measured. The sensor unit 27 may measure the nitrogen ion concentration of the absorbent or the nitrogen ion concentration of the exhaust gas using, for example, ion chromatography. Ion chromatography is a separation method in which the movement speed of ions is changed according to the difference in affinity of ions, so that each ion is separated. Since it is a known technique, a detailed description thereof will be omitted. When the nitrogen ion concentration of the absorbent or the nitrogen ion concentration of the exhaust gas measured by the sensor unit 27 is greater than or equal to the reference value, the by-product separation units 25 and 25' operate to adsorb by-products included in the absorbent. If necessary, a bypass pipe (not shown) bypassing the by-product separation units 25 and 25' may be connected to the second flow pipe 24, and the bypass pipe may contain nitrogen ions of the absorbent measured by the sensor unit 27. It can be opened when the concentration or nitrogen ion concentration of the exhaust gas is less than the standard value.

Hereinafter, with reference to FIGS. 4 and 5, the operation of the exhaust gas treatment device 1 will be described in more detail.

4 and 5 are operation diagrams for explaining the operation of the exhaust gas treatment device.

The exhaust gas treatment device 1 according to the present invention uses the chemical adsorption properties of the ion exchange resins 251a and 251b to separate by-products generated by the decomposition of the absorbent from the absorbent, thereby maintaining the purity of the absorbent. Therefore, it is possible to prevent the carbon dioxide capture efficiency of the carbon dioxide capture device 20 from deteriorating, and also to prevent by-products from being discharged together with the exhaust gas to the top of the absorption tower 21 to cause air pollution. In addition, since by-products are desorbed when ionized water is supplied to the ion exchange resins 251a and 251b adsorbed with by-products, it is possible to use them semi-permanently, thereby reducing operating costs of the device.

4 and 5 are views illustrating a process in which a plurality of by-product separation units are selectively driven and the by-products included in the absorbent are separated.

First, referring to FIG. 4 , the exhaust gas generated in the combustion engine 100 moves to the economizer 12 along the exhaust pipe 10, and waste heat is recovered, and the exhaust pipe 10 and the branch pipe are connected at the rear end of the economizer 12. (11a). The control valve 11 controls the amount of exhaust gas flowing through the exhaust pipe 10 and the amount of exhaust gas branched to the branch pipe 11a, and the exhaust gas flowing through the exhaust pipe 10 is discharged into the atmosphere, Exhaust gas diverted to the engine 11a is supplied to the cooling tower 13. The cooling tower 13 cools the exhaust gas by injecting cooling water into the exhaust gas, and the cooling water whose temperature has increased by exchanging heat with the exhaust gas is discharged from the cooling tower 13 and then circulated back to the cooling tower 13 through a series of cooling processes. . The exhaust gas cooled by heat exchange with the cooling water is supplied to the absorption tower 21 along the branch pipe 11a.

The exhaust gas supplied to the absorption tower 21 comes into gas-liquid contact with the absorbent, whereby carbon dioxide contained in the exhaust gas is absorbed by the absorbent and can be removed from the exhaust gas. The exhaust gas from which carbon dioxide is removed may be discharged through a branch pipe 11a after undergoing a separate cooling process at the top of the absorption tower 21.

Meanwhile, the absorbent that has absorbed carbon dioxide is discharged through the first flow pipe 23 and pressurized by the pump 23a, and the absorption tower 21 passes through the second flow pipe 24 in the heat exchanger 241 located at the rear end of the pump 23a. ), heated by heat exchange with the absorbent circulated, and then supplied to the regeneration tower 22. As the absorbent supplied to the regeneration tower 22 flows from the top to the bottom of the regeneration tower 22, carbon dioxide is separated by thermal energy, and some of the absorbent from which the carbon dioxide is separated is sent to the reboiler 31 through the circulation line 30. After being introduced and heated, it is circulated back to the regeneration tower (22). At this time, in the regeneration tower 22, some of the absorbent may be thermally decomposed to form by-products. The carbon dioxide separated from the absorbent is discharged to the upper part of the regeneration tower 22 and passes through the condenser 221 and the reflux drum 222 in turn to remove moisture, and the carbon dioxide from which the moisture has been removed is supplied to the required place through a separate compression process. do. The remaining part of the absorbent from which carbon dioxide is separated passes through the heat exchanger 241, the pump 242, and the cooler 243 sequentially through the second flow pipe 24 in a state containing by-products, and is cooled by the absorption tower 21. supplied with The sensor unit 27 measures the nitrogen ion concentration of the absorbent supplied to the absorption tower 21, and when the nitrogen ion concentration of the absorbent measured by the sensor unit 27 is greater than a reference value, the by-product separation units 25 and 25' this works More specifically, the absorbent containing by-products passing through the cooler 243 is supplied to one of a plurality of by-product separation units 25 and 25' installed in parallel on the second flow pipe 24, and the by-products to which the absorbent is supplied The separation unit 25 separates by-products included in the absorbent by using the chemical adsorption properties of the ion exchange resins 251a and 251b. As the absorbent sequentially passes through the first separation unit 25a and the second separation unit 25b, the ionized nitrogen compound is separated, and thus, the by-product is removed through the second flow pipe 24 through the absorption tower ( 21) can be supplied. Salts generated as the by-products are adsorbed to the ion exchange resins 251a and 251b are discharged through the discharge pipe 253b and may be separately stored or subjected to a separate treatment process.

5, when the by-product separation unit 25 is used for a long time, the anion exchange resin 251a of the first separation unit 25a and the cation exchange resin 251b of the second separation unit 25b Adsorption capacity may decrease due to excessive adsorption of by-products on the surface. The by-product separation unit 25, in which the adsorption capacity of the ion exchange resins 251a and 251b is reduced, receives ionized water from the ionized water supply pipe 26 without receiving an absorbent and desorbs the by-products adsorbed on the ion exchange resins 251a and 251b. can make it The regeneration water containing the by-products separated from the ion exchange resins 251a and 251b is discharged through the discharge pipe 253b and may be separately stored or subjected to a separate treatment process.

Meanwhile, while the regeneration process is in progress in the by-product separation unit 25, the remaining by-product separation unit 25' receives an absorbent and separates the by-products. The absorbent from which by-products are separated in the by-product separation unit 25' may be supplied to the absorption tower 21 through the second flow pipe 24.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

1: Exhaust gas treatment device
10: exhaust pipe 11: control valve
11a: branch pipe 12: economizer
13: cooling tower 20: carbon dioxide capture device
21: absorption tower 22: regeneration tower
23: first flow pipe 24, 24a, 24b: second flow pipe
241: heat exchanger 25, 25 ': by-product separation unit
25a: first separation unit 25b: second separation unit
251a: anion exchange resin 251b: cation exchange resin
252a: first chamber 252b: second chamber
253b: discharge pipe 26: ionized water supply pipe
27: sensor unit 30: circulation line
31: reboiler
100: combustion engine

Claims (7)

An exhaust pipe for discharging exhaust gas generated from a combustion engine, and
A carbon dioxide collecting device installed on the exhaust pipe to remove carbon dioxide contained in the exhaust gas,
The carbon dioxide capture device,
an absorption tower injecting an absorbent for absorbing carbon dioxide into the exhaust gas;
a regeneration tower which separates carbon dioxide from the absorbent by heating the absorbent in which the carbon dioxide supplied from the absorption tower is absorbed;
A first flow pipe connecting the absorption tower and the regeneration tower to supply the absorbent in which carbon dioxide is absorbed to the regeneration tower;
A second flow pipe connecting the regeneration tower and the absorption tower to circulate the absorbent from which carbon dioxide is separated to the absorption tower; and
and a by-product separation unit installed on the second flow pipe and separating by-products generated by decomposition of the absorbent heated in the regeneration tower from the absorbent. The method of claim 1, wherein the by-product separation unit,
An exhaust gas treatment device comprising an ion exchange resin for chemically adsorbing the by-product and a chamber accommodating the ion exchange resin. The method of claim 2, wherein the by-product separation unit,
A first separation unit including a plurality of anion exchange resins adsorbing nitrite ions (NO ₂ ^- ) and nitrate ions (NO ₃ ^- ), which are anions among the by-products, and a first chamber accommodating the anion exchange resins;
A second separation unit including a plurality of cation exchange resins adsorbing ammonium ions (NH ₃ ⁺ ), which are cations, among the by-products, and a second chamber accommodating the cation exchange resins, disposed at the front or rear of the first separation unit. An exhaust gas treatment device comprising a separation unit. According to claim 3,
and an ion water supply pipe supplying ion water to the by-product separation unit to desorb the by-product adsorbed on the ion exchange resin. According to claim 4,
As the anions contained in the ionized water are adsorbed to the anion exchange resin, the nitrite ions and nitrate ions are desorbed from the anion exchange resin;
An exhaust gas treatment device in which the ammonium ions are desorbed from the cation exchange resin while the cations included in the ionized water are adsorbed to the cation exchange resin. According to claim 3,
A plurality of the by-product separation units are installed in parallel and are selectively driven. According to claim 2,
It is installed in the second flow pipe at the rear of the by-product separation unit to measure the nitrogen ion concentration of the absorbent circulated to the absorption tower, or installed in the exhaust pipe at the rear of the absorption tower to measure the nitrogen of the exhaust gas discharged from the absorption tower. Further comprising a sensor unit for measuring the ion concentration,
When the nitrogen ion concentration of the absorbent or the nitrogen ion concentration of the exhaust gas measured by the sensor unit is greater than or equal to a reference value, the by-product separation unit operates to adsorb the by-product.

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