KR101138188B1 - Apparatus of recovering carbon dioxide from flue gas and the method thereof - Google Patents

Abstract

CO2 using ammonia water can minimize wastewater discharge from the condensate tower while minimizing the amount of washing water used, preventing the pipes from being closed by ammonia salts, and reducing operating and wastewater treatment costs. A recovery apparatus and a method of recovering carbon dioxide using the same are introduced.

The carbon dioxide recovery apparatus using ammonia water separates ammonia from the absorption tower 100 having the washing unit 110 integrally, the regeneration tower 200 for regenerating the absorption liquid, and the washing water used in the absorption tower 100. And a concentration tower 300 separating and discharging the ammonia separated through the provided condenser 310 and the drum 320 into a high concentration of ammonia water and a high concentration of ammonia gas, respectively, and the high concentration ammonia water of the absorption tower 100. Ammonia water transfer pipe 10 connecting the condenser 310 and the lower part of the absorption tower 100 is installed to be reused as a replenishing absorbent liquid, and the high concentration ammonia gas may be recovered from the regeneration tower 200. The ammonia gas transfer pipe 11 connecting the drum 320 and the lower part of the regeneration tower 200 is installed.

Absorption Tower, Regeneration Tower, Concentration Tower, Wastewater, Washing Water

Description

Apparatus for recovering carbon dioxide using ammonia water and method for recovering carbon dioxide using the same {APPARATUS OF RECOVERING CARBON DIOXIDE FROM FLUE GAS AND THE METHOD THEREOF}

The present invention relates to a carbon dioxide recovery apparatus using ammonia water and a method for recovering carbon dioxide using the same, and more particularly, to minimize the amount of waste water discharged from the concentration tower and to minimize the amount of washing water used, and to close the pipe by the ammonia salt. The present invention relates to a carbon dioxide recovery apparatus using ammonia water and a method of recovering carbon dioxide using the same, which can prevent a phenomenon from occurring and reduce operating costs and wastewater treatment costs.

In general, adsorption, absorption, membrane separation, and the like are used as a method for separating and removing carbon dioxide contained in exhaust gas.

Here, in the absorption method, a carbon dioxide absorption liquid is used to separate and remove carbon dioxide contained in the exhaust gas. Thus, the absorption liquid which consists of an amine compound is commonly used for the carbon dioxide absorption liquid used at the time of the separation of the carbon dioxide contained in exhaust gas using the absorption method.

However, when the amine compound is used as the absorbent liquid used to separate carbon dioxide from the flue gas, the overall cost increases because the amine compound is expensive, and the mechanism for absorbing and separating carbon dioxide from the flue gas by the amine compound is corroded. There was a problem that maintenance was required.

On the other hand, ammonia water has recently attracted attention for absorbing and removing carbon dioxide from flue gas, which is relatively inexpensive and reduces the problem of corrosion of machinery for absorbing and separating carbon dioxide from flue gas compared to amine compounds. This is because not only the reduction but also the consumption of renewable energy is low as the regeneration temperature is lower than that of the amine compound.

Meanwhile, Bai and Yeh published a research paper (Ind.Eng.Chem.Res.1997, 36, 2490) on how to absorb and remove carbon dioxide using ammonia water, and Resnik et al. Also called Aquar Ammonia Process. Announced the absorption process (Int. J. of Env. Technology & Management, Vol. 4, No. 1).

In addition, the Republic of Korea Patent No. 10-0703999 No. 5-15wt% ammonia water solution is supplied to the upper portion of the first absorption tower at 20 ~ 40 ℃, and mixed by introducing a mixed gas containing carbon dioxide to the lower portion of the first absorption tower The carbon dioxide contained in the gas is absorbed into ammonia water, and carbon dioxide-containing ammonia water absorbed by the carbon dioxide is sent to a stripping column and heated to 70 to 88 ° C. to remove carbon dioxide. The process of absorbing carbon dioxide by sending the removed carbon dioxide to the third absorption tower while recirculating to remove the trace amount of ammonia contained in the carbon dioxide with water is proposed.

However, this process of absorbing carbon dioxide using ammonia water is similar to the process presented in the previously published paper (Int. J. of Thermodynamics, vol. 7, pp. 173-181). In order to remove ammonia from the regeneration tower, a separate washing tower is installed to solve the problem of ammonia simply being discharged to the gas phase.However, if ammonia reacts with carbon dioxide and the temperature is low, the pipe is closed by the ammonia salt. Due to the high vapor pressure of ammonia, when ammonia water and exhaust gas contacted in the absorption tower, a considerable amount of ammonia contained in the ammonia water was volatilized. In order to capture the volatilized ammonia, a large amount of washing water must be consumed. And the gas discharged from the regeneration tower To capture the ammonia contained in the ammonia is problem that can not be sufficiently trapped occurred when used again.

In addition, when the whole amount of washing water is supplied from the outside, a large amount of washing water is required to increase the operating cost, and the amount of washing water must be discharged to the waste water, thereby increasing the cost for waste water treatment.

In addition, the washing water used to capture the ammonia in the gas discharged from the absorption tower and the regeneration tower is sent to the concentration tower by heating the washing water used to contain a large amount of ammonia to separate the water and ammonia In this case, when the concentrated ammonia is injected into the bottom of the regeneration tower, it is difficult to maintain the ammonia concentration uniformly in the regeneration tower, and the washing water in which the ammonia is collected is introduced into the top of the regeneration tower. When reboiling at, there was a problem that a lot of energy must be supplied.

The present invention has been proposed to solve the problems described above, by reusing or recapturing a high concentration of ammonia water and a high concentration of ammonia gas discharged from the condenser of the concentration tower to recover and recycle as much as possible ammonia from the concentration tower Some or all of the discharged wastewater can be reused as the washing water in the absorption tower to minimize the wastewater discharge and minimize the amount of washing water used. The washing water supplied to the washing section of the regeneration tower is supplied from the outside and discharged. By reusing the effluent water into the water of the absorption tower, the efficiency of cleaning of the absorption tower can be increased, thereby minimizing the emission of ammonia into the air, and reducing the operating cost and wastewater treatment cost. An object of the present invention is to provide a carbon dioxide recovery method.

A carbon dioxide recovery apparatus using ammonia water according to the present invention for achieving the above object is a carbon dioxide recovery apparatus for recovering carbon dioxide from the exhaust gas containing carbon dioxide by using an absorption liquid consisting of ammonia water, the absorption liquid is in contact with the exhaust gas to exhaust gas An absorption tower including an integrated washing unit for removing carbon dioxide in the absorbent solution and collecting volatilized ammonia from the absorbent liquid, a regeneration tower for regenerating the absorbent liquid by removing carbon dioxide contained in the absorbent liquid, and the absorption unit Separation ammonia from the washing water used in the tower, and a concentrated tower for separating and discharging the ammonia separated through the condenser and the drum to a high concentration of ammonia water and a high concentration of ammonia gas, the high concentration ammonia water in the absorption tower Supplemental absorption An ammonia water transport pipe is installed to connect the condenser and the lower part of the absorption tower so as to be reused, and an ammonia gas transport pipe is connected between the drum and the lower part of the regeneration tower so that the high concentration ammonia gas can be recovered from the regeneration tower. It is characterized in that it is installed.

The wastewater return pipe connecting the wastewater pipe and the cleaning water supply pipe for the absorption tower is installed so that some or all of the wastewater discharged along the wastewater pipe installed at the bottom of the concentration tower is reused as the washing water in the absorption tower. desirable.

The regeneration tower is preferably provided with a washing unit integrally collecting the ammonia discharged during the regeneration of the absorbent liquid using the washing water.

The washing unit of the regeneration tower is provided with a washing water supply pipe for supplying from the outside, and collects ammonia discharged during regeneration of the absorbent liquid, and then discharges the effluent discharged from the washing unit to be reused as the washing water in the absorption tower. It is preferable that an outflow water return pipe connecting the lower part of the part and the cleaning water supply pipe for cleaning the absorption tower is installed.

In addition, the carbon dioxide recovery method using ammonia water according to the present invention for achieving the above object, by removing the carbon dioxide in the exhaust gas by contacting the absorbent liquid consisting of ammonia water with the exhaust gas containing carbon dioxide, the volatilized from the absorbent liquid using the washing water An absorption tower including a washing unit for collecting ammonia and a washing unit for removing the carbon dioxide contained in the absorbent liquid to regenerate the absorbent liquid and collecting the ammonia discharged during the regeneration of the absorbent liquid using washing water are integrally provided. Ammonia water including a regeneration tower, and a concentration tower for separating ammonia from the washing water used in the absorption tower and separating and discharging the ammonia separated through the condenser and the drum into high concentration ammonia water and high concentration ammonia gas, respectively. CO2 recovery system A method of recovering carbon dioxide by using the method, the high concentration ammonia water is transferred to the lower portion of the absorption tower so that the high concentration ammonia water can be reused as a replenishment absorbent liquid, and the high concentration ammonia gas is transferred to the lower portion of the regeneration tower so that the high concentration ammonia gas is It is characterized in that the re-collection.

Part or all of the wastewater discharged from the concentration tower is preferably transferred to the washing unit of the absorption tower so that the wastewater is reused as the washing water.

The washing unit of the regeneration tower may be supplied with washing water for cleaning from the outside, and the effluent water discharged from the washing unit may be transferred to the washing unit of the absorption tower so that the effluent is reused as the washing water in the absorption tower.

According to the carbon dioxide recovery apparatus using the ammonia water and the carbon dioxide recovery method using the same, the high concentration of ammonia water and the high concentration of ammonia gas discharged from the condenser of the concentration tower can be reused or recaptured to recover and recycle the ammonia as much as possible, Some or all of the wastewater discharged from the concentration tower can be reused as the washing water of the absorption tower to minimize wastewater discharge, minimize the amount of washing water used, and cleanse the water supplied to the washing section of the regeneration tower. By increasing the cleaning efficiency of the absorption tower scrubber by reusing the effluent supplied from and discharged from the scrubber to the absorption tower scrubber, the emission of ammonia into the air can be minimized and the operating cost and wastewater treatment cost can be reduced. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only, and various modifications may be made without departing from the technical gist of the present invention.

1 is a schematic view showing a carbon dioxide recovery apparatus using ammonia water according to the present invention.

As shown, the carbon dioxide recovery apparatus using ammonia water according to an embodiment of the present invention has a configuration including an absorption tower 100, the regeneration tower 200 and the concentration tower (300). Here, the concentration tower 300 is provided with a condenser 310 and a drum 320 connected to the upper portion of the condenser 310, the absorption tower 100, the regeneration tower 200, the concentration tower 300 A plurality of interconnecting pipes are installed.

The absorption tower 100 is to remove carbon dioxide in the exhaust gas by contacting the exhaust gas introduced into the absorption tower 100 through the exhaust gas inlet pipe 1 with an absorption liquid made of ammonia water, and the absorption tower 100 is cleaned. A washing unit 110 for collecting ammonia volatilized from the absorbent liquid by using water is provided integrally. When the cleaning unit 110 is integrally provided as described above, it is not necessary to install a separate device to collect the ammonia volatilized from the absorbent liquid, so that the ammonia contained in the exhaust gas can be more easily removed.

A washing water supply pipe 15 for supplying washing water for cleaning from the outside to the washing unit 110 is installed at an upper portion of the washing unit 110, and ammonia is collected at the lower portion of the washing unit 110. A washing water transport pipe 8 for transferring the washing water to the concentration tower 300 is installed, and the washing water transport pipe 8 is connected to the concentration tower 300. Meanwhile, an exhaust gas discharge pipe 2 for discharging exhaust gas from which carbon dioxide is removed is installed at an upper portion of the absorption tower 100, and an absorption liquid absorbing carbon dioxide in exhaust gas is disposed at the lower portion of the absorption tower 100. An absorbent liquid conveying tube 3 for transferring to 200 is installed, and the absorbent liquid conveying tube 3 is connected to an upper portion of the regeneration tower 200.

On the other hand, the absorbent liquid transfer pipe 3 is provided with an absorbent liquid heat exchanger 50 for cooling the absorbent liquid at a constant temperature.

The regeneration tower 200 is for regenerating the absorption liquid by removing carbon dioxide contained in the absorption liquid used in the absorption tower 100, and the regeneration tower 200 uses the washing water to regenerate the absorption liquid. The washing unit 210 for collecting the discharged ammonia is provided as an integral. As such, when the washing unit 210 is integrally provided, it is not necessary to install a separate device to collect the ammonia separated from the regeneration absorbing liquid, so that the ammonia contained in the carbon dioxide can be more easily removed.

The upper part of the washing unit 210 is provided with a washing water supply pipe 6 for supplying the washing water for washing to the washing unit 210 from the outside, the lower portion of the washing unit 210 to collect ammonia The outflow water return pipe 7 is installed to allow the outflow water (which is used washing water for cleaning) to be reused as the wash water in the absorption tower 100 after being discharged from the washing unit 210, and the outflow water return pipe 7 is provided. Is connected to the washing water supply pipe (15).

Meanwhile, a carbon dioxide discharge pipe 4 for discharging carbon dioxide separated from the absorbent liquid during the regeneration of the absorbent liquid is installed at the upper portion of the regeneration tower 200, and the regenerated absorbent liquid is disposed at the lower portion of the regeneration tower 200. A regeneration absorbent liquid conveying tube 5 for transferring to the absorption tower 100 is installed, and the regenerated absorbent liquid conveying tube 5 is connected to the upper portion of the absorbing tower 100 via the absorbent liquid heat exchanger 50.

In addition, a regeneration tower reboiler 20 is installed below the regeneration tower 200 to circulate the regenerated absorbent liquid so that all of the carbon dioxide contained in the regenerated absorbent liquid may be recovered.

The concentrating tower 300 separates ammonia from the washing water used in the absorption tower 100 and converts the ammonia separated through the condenser 310 and the drum 320 into a high concentration of ammonia water and a high concentration of ammonia gas. In order to separate and discharge the ammonia, an ammonia transport pipe 9 for transporting the ammonia separated from the washing water to the condenser 310 is installed at an upper portion of the concentration tower 300. Is connected to the condenser 310.

On the other hand, the condenser 310 is provided with an ammonia water transfer pipe 10 for reusing the high concentration ammonia water discharged from the condenser 310 as a replenishment absorbent in the absorption tower 100, the ammonia water transfer pipe 10 is It is connected to the lower portion of the absorption tower (100).

On the other hand, the drum 320 is provided with an ammonia gas conveying pipe 11 for allowing the high concentration ammonia gas discharged from the drum 320 to be recovered from the regeneration tower, and the ammonia gas conveying pipe 11 is It is connected to the bottom of the regeneration tower 200.

On the other hand, a wastewater pipe 12 for discharging wastewater from which ammonia is separated from the washing water used in the absorption tower 100 is installed below the concentration tower 300, and the wastewater pipe 12 is provided with wastewater. The cooler 40 for cooling to a predetermined temperature is installed.

On the other hand, the wastewater pipe 12 is provided with a wastewater return pipe 14 for allowing some or all of the wastewater discharged to be reused as the washing water in the absorption tower 100, the wastewater return pipe 14 is It is connected to the washing water supply pipe 15 for washing.

On the other hand, the waste water pipe 12 is provided with a drain pipe 13 for discharging waste water that is not reused as the washing water.

Meanwhile, a concentrated tower reboiler 30 is installed at the lower portion of the concentrated tower 300 to circulate the discharged wastewater so that all ammonia contained in the wastewater can be recovered.

Hereinafter, a method for recovering carbon dioxide using ammonia water according to an embodiment of the present invention will be described with reference to FIG. 1, which includes overall absorption of carbon dioxide in exhaust gas in an absorption tower, washing water regeneration in a regeneration tower, and ammonia concentration in a concentration tower. Explain in detail with the process.

When the exhaust gas is introduced into the absorption tower 100 through the exhaust gas inlet pipe 1, the absorbing liquid made of ammonia water and the exhaust gas are contacted, so that the carbon dioxide in the exhaust gas is absorbed into the absorbing liquid and carbon dioxide is removed from the exhaust gas. Here, the temperature of the absorption liquid is preferably 20 ~ 50 ℃, the exhaust gas from which carbon dioxide is removed is transferred to the upper portion of the absorption tower 100 is discharged through the exhaust gas discharge pipe (2).

At this time, a large amount of ammonia is removed from the absorbent liquid due to high volatility, and the ammonia removed is collected by the washing water introduced into the washing unit 110 through the washing water supply pipe 15, and the ammonia is collected. The washing water for washing is transferred to the concentration tower 300 through the washing water transfer pipe 8.

On the other hand, the absorbent liquid absorbing carbon dioxide from the exhaust gas is transferred to the upper part of the regeneration tower 200 through the absorbent liquid transfer pipe 3 installed in the lower part of the absorption tower 100 to be regenerated, and the absorbent liquid heat exchanger 50 in the process of being transferred. By cooling to a constant temperature. Carbon dioxide is separated from the absorbent liquid in the regeneration process by heating in the regeneration tower 200, and the separated carbon dioxide is transferred to the upper portion of the regeneration tower 200 and discharged through the carbon dioxide discharge pipe 4.

At this time, a large amount of ammonia is removed from the regenerated absorbent liquid, and the ammonia removed is collected by the washing water introduced into the washing unit 210 through the washing water supply pipe 6 for washing, and the ammonia is collected for washing. The effluent water, which is the washing water, is transferred to the washing water supply pipe 15 through the effluent return pipe 7 to be reused as the washing water for washing in the absorption tower 100, and the regenerated absorbent liquid is transferred to the regeneration absorbent liquid transport pipe 5. Transfer to the upper portion of the absorption tower 100 through, the carbon dioxide contained in the regeneration absorbent liquid is recovered as the regenerated absorbent liquid circulates the regeneration tower reboiler 20.

On the other hand, when the whole amount of washing water and washing water are supplied from the outside, a large amount of washing water is required, which increases the operating cost and also discharges the amount of washing water into the waste water. Will increase. In addition, since the amount of ammonia stripped from the absorbent liquid in the regeneration tower 200 corresponds to about 1/8 compared with the amount of ammonia stripped from the absorption tower 100, the washing unit 210 through the washing water supply pipe 6 for cleaning. A small amount of the washing water to be introduced into) is sufficient. Therefore, as described above, fresh washing water from the outside may be used as the washing water, and a large amount of washing water may be saved by reusing the washing water, that is, the effluent, collected with ammonia as the washing water. Operating costs and wastewater treatment costs can also be reduced.

Meanwhile, the washing water for collecting ammonia transferred from the washing unit 110 of the absorption tower 100 to the upper portion of the concentration tower 300 is heated in the concentration tower 300, and the ammonia from the heated washing water is heated. Is evaporated and separated, and the separated ammonia is condensed into a high concentration of ammonia water in the condenser 310 provided at the top of the concentration tower 300, and the uncondensed ammonia is disposed at the top of the condenser 310. Is trapped in a high concentration of ammonia gas.

The high concentration of ammonia water is transferred to the lower portion of the absorption tower 100 through the ammonia water transfer pipe 10 and reused as a supplemental absorption liquid, and the high concentration ammonia gas of the regeneration tower 200 is transferred through the ammonia gas transfer pipe 11. It is transported to the bottom and recovered. The recovery in the regeneration tower 200 for the high concentration of ammonia gas is to recover and recycle ammonia as much as possible, and by the recovery of such a high concentration of ammonia gas, the emission of ammonia into the atmosphere can be minimized, and the running cost is high. Can be saved.

Meanwhile, wastewater from which ammonia is separated from the washing water used in the absorption tower 100 is transferred to the lower portion of the concentration tower 300, discharged through the wastewater pipe 12, and cooled to a predetermined temperature by the cooler 40. do. At this time, some or all of the cooled waste water is transferred to the washing water supply pipe 15 through the waste water return pipe 14 and reused as the washing water for washing in the absorption tower 100, and reused as the washing water for washing. Waste water is not discharged through the drain pipe 13, and the ammonia contained in the waste water is recovered as the waste water circulates through the enrichment tower reboiler (30).

Since the ammonia concentration of the waste water is 10 ppm or less, it can be sufficiently reused as washing water for washing, and new washing water for washing is supplied through the washing water supply pipe 15 by an amount discharged through the drain pipe 13. . At this time, the total amount of washing water supplied to the washing unit 110 of the absorption tower 100 is determined according to the process operating conditions and the concentration of ammonia discharged, and the washing unit 110 and the regeneration tower of the absorption tower 100 ( It is preferable to operate the concentration of ammonia in the gas discharged from the washing unit 210 of 200) to 10 ppm or less.

On the other hand, the heating temperature for separating the ammonia in the concentration tower 300 is different depending on the ammonia concentration of the washing water transferred to the concentration tower 300 is preferably 80 ~ 90 ℃, concentration tower reboiler 30 The temperature is preferably maintained at 100 to 115 ° C. This is because moisture must be partially evaporated in order to condense a high concentration of ammonia water in the condenser 310.

Hereinafter, an Example is given and this invention is demonstrated in detail. The embodiments described below are intended to specifically illustrate the present invention, which will be apparent that the scope of the present invention is not limited.

Example 1

A flue gas containing carbon dioxide (CO ₂ ) having a volume of 25% relative to the total weight is supplied at a flow rate of 50 Nm ³ / hr through a flue gas inlet pipe 1 installed at one lower portion of the absorption tower 100 at a concentration of 5% As a result of supplying ammonia water to the absorption tower 100 at a flow rate of 650 kg / hr to absorb and remove carbon dioxide in the exhaust gas, the cleaning unit 110 and the cleaning unit 210 of the absorption tower 100 and the regeneration tower 200 were not operated. The ammonia concentration in the flue gas discharged from the absorption tower 100 and the ammonia concentration in the carbon dioxide discharged from the regeneration tower 200 when it was absent were 0.6 to 1.6%, and the concentration was high.

On the other hand, as a result of supplying the washing water for washing to the washing unit 210 of the regeneration tower 200 at a flow rate of 10 kg / hr, the ammonia concentration in the carbon dioxide discharged from the regeneration tower 200 was 1 ~ 5ppm, As a result of supplying the washing water for cleaning at a flow rate of 90 kg / hr through the washing water supply pipe 15 and the outflow water return pipe 7, the washing unit 110 of the absorption tower 100 was discharged from the absorption tower 100. The ammonia concentration in the exhaust gas was about 25 ppm, the carbon dioxide removal efficiency in the absorption tower 100 was 90%, and the carbon dioxide concentration in the carbon dioxide discharge pipe 4 of the regeneration tower 200 was 96%.

At this time, the regeneration temperature of the regeneration tower 200 was 85 ℃, the operating temperature of the concentration tower 300 was 110 ℃, the ammonia concentration in the wastewater generated was about 5ppm, about 30% of the wastewater drain pipe (13) The remaining 70% was transferred to the washing water supply pipe 15 for cleaning through the waste water return pipe 14 and used as the washing water for washing.

Example 2

A flue gas containing carbon dioxide (CO ₂ ) having a volume of 25% relative to the total weight is supplied at a flow rate of 50 Nm ³ / hr through a flue gas inlet pipe 1 installed at one lower portion of the absorption tower 100 and a 7% concentration of As the ammonia water was supplied to the absorption tower 100 at a flow rate of 500 kg / hr to absorb and remove carbon dioxide in the exhaust gas, the cleaning unit 110 and the cleaning unit 210 of the absorption tower 100 and the regeneration tower 200 were not operated. The ammonia concentration in the flue gas discharged from the absorption tower 100 and the ammonia concentration in the carbon dioxide discharged from the regeneration tower 200 when not in use were 0.5 to 2%, and the concentration was high.

On the other hand, as a result of supplying the washing water for washing to the washing unit 210 of the regeneration tower 200 at a flow rate of 10 kg / hr, the ammonia concentration in the carbon dioxide discharged from the regeneration tower 200 was 1 ~ 5ppm, As a result of supplying the washing water for washing at a flow rate of 100 kg / hr through the washing water supply pipe 15 and the outflow water return pipe 7, the washing unit 110 of the absorption tower 100 was discharged from the absorption tower 100. The ammonia concentration in the exhaust gas was about 25 ppm, the carbon dioxide removal efficiency in the absorption tower 100 was 90%, and the carbon dioxide concentration in the carbon dioxide discharge pipe 4 of the regeneration tower 200 was 96%.

At this time, the regeneration temperature of the regeneration tower 200 was 85 ℃, the operating temperature of the concentration tower 300 was 110 ℃, the ammonia concentration in the generated wastewater was about 5ppm, about 50% of the wastewater drain pipe (13) The remaining 50% was transferred to the washing water supply pipe 15 for cleaning through the waste water return pipe 14 and used as the washing water for washing.

According to the first and second embodiments described above, it can be seen that the ammonia concentration in the exhaust gas discharged from the absorption tower 100 and the ammonia concentration in the carbon dioxide discharged from the regeneration tower 200 are significantly reduced, which is the maximum recovery of ammonia. By reducing the ammonia concentration, the production of ammonia salts is suppressed and the pipe closing phenomenon does not occur, and by using the wastewater of the concentrating tower 300, the additional amount of water used as the washing water is reduced, thereby reducing the operating cost and Wastewater treatment costs can be reduced.

While specific embodiments of the present invention have been illustrated and described, those of ordinary skill in the art may vary the present invention without departing from the spirit of the invention as set forth in the following claims. It is to be understood that modifications and variations are possible.

1 is a schematic view showing a carbon dioxide recovery apparatus using ammonia water according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: exhaust gas inlet pipe 2: exhaust gas discharge pipe

3: absorbent liquid transfer pipe 4: carbon dioxide discharge pipe

5: regeneration absorbent liquid transfer pipe 6: washing water supply pipe for washing

7: Outflow water return pipe 8: Washing water transport pipe

9: ammonia transfer tube 10: ammonia water transfer tube

11: ammonia gas transfer pipe 12: waste water pipe

13: drain pipe 14: wastewater return pipe

15: washing water supply pipe for cleaning 20: re-boiling regeneration tower

30: reheating tower 40: cooler

50: absorption liquid heat exchanger 100: absorption tower

110: cleaning unit 200: regeneration tower

210: washing unit 300: concentration tower

310: condenser 320: drum

Claims (7)

A carbon dioxide recovery apparatus for recovering carbon dioxide from exhaust gas containing carbon dioxide by using an absorption liquid made of ammonia water, An absorption tower 100 in which the absorption liquid is contacted with the exhaust gas to remove carbon dioxide in the exhaust gas, and a washing unit 110 integrally collecting the ammonia volatilized from the absorption liquid using the washing water; A regeneration tower 200 which regenerates the absorbent liquid by removing carbon dioxide contained in the absorbent liquid; And A concentration tower for separating ammonia from the washing water used in the absorption tower 100, and separated and discharged ammonia separated through the condenser 310 and the drum 320 to a high concentration of ammonia water and a high concentration of ammonia gas ( 300), An ammonia water transfer pipe 10 connecting the condenser 310 and the lower part of the absorption tower 100 is installed so that the high concentration ammonia water is reused as a supplemental absorption liquid in the absorption tower 100, and the high concentration ammonia gas is Carbon dioxide recovery apparatus using ammonia water, characterized in that the ammonia gas transfer pipe (11) connecting the drum 320 and the lower part of the regeneration tower 200 is installed to be recovered from the regeneration tower (200). The method according to claim 1, Some or all of the wastewater discharged along the wastewater pipe 12 installed at the bottom of the concentration tower 300 is reused as the washing water in the absorption tower 100 of the wastewater pipe 12 and the absorption tower 100. A carbon dioxide recovery apparatus using ammonia water, characterized in that the waste water return pipe (14) connecting the washing water supply pipe (15) for cleaning. The method according to claim 1 or 2, The regeneration tower 200 is a carbon dioxide recovery apparatus using ammonia water, characterized in that the washing unit 210 is integrally provided with a collection unit for collecting ammonia discharged when the absorption liquid is regenerated using the washing water. The method of claim 3, The washing unit 210 of the regeneration tower 200 is provided with a washing water supply pipe 6 supplied from the outside, and collects ammonia discharged during regeneration of the absorbent liquid, and then discharges the effluent discharged from the washing unit 210. That the outflow water return pipe 7 connecting the lower portion of the washing unit 210 and the washing water supply pipe 15 for the absorption tower 100 to be reused as the washing water in the absorption tower 100 is installed. Carbon dioxide recovery apparatus using ammonia water characterized in that. Absorption tower 100 having an ammonia water in contact with the exhaust gas containing carbon dioxide to remove the carbon dioxide in the exhaust gas, the washing unit 110 to collect ammonia volatilized from the absorption liquid using the washing water as an integral unit And a regeneration tower 200 in which an absorption unit is regenerated by removing carbon dioxide contained in the absorbent liquid, and a washing unit 210 which collects ammonia discharged during regeneration of the absorbent liquid using washing water is integrally provided. A concentrated tower 300 for separating ammonia from the washing water used in the absorption tower 100, and separating and discharging the ammonia separated through the condenser 310 and the drum 320 provided to a high concentration of ammonia water and a high concentration of ammonia gas, respectively (300). As a method of recovering carbon dioxide by using a carbon dioxide recovery apparatus using ammonia water, including, The high concentration ammonia water is transferred to the lower portion of the absorption tower 100 to reuse the high concentration ammonia water as a supplemental absorption liquid, and the high concentration ammonia gas is transferred to the lower portion of the regeneration tower 200 so that the high concentration ammonia gas is recovered. Carbon dioxide recovery method using ammonia water, characterized in that. The method according to claim 5, Carbon dioxide recovery method using ammonia water, characterized in that for transferring some or all of the waste water discharged from the concentration tower 300 to the washing unit 110 of the absorption tower 100 to be reused as the washing water. The method according to claim 5 or 6, The washing unit 210 of the regeneration tower 200 is supplied with the washing water for cleaning from the outside, and the effluent water discharged from the washing unit 210 is transferred to the washing unit 110 of the absorption tower 100 to the effluent water. Carbon dioxide recovery method using ammonia water, characterized in that to be reused as the washing water in the absorption tower (100).

Images