KR20190079235A - Carbon dioxide recovery and power generation system - Google Patents

Abstract

According to the present invention, a carbon dioxide recovery and power generation system comprises: an absorption tower provided with an inlet into which exhaust gas flows, and accommodating an absorption agent therein to adsorb carbon dioxide in the exhaust gas; a regeneration tower provided with the absorption agent to adsorb the carbon dioxide from the absorption tower, and heating the absorption agent to separate the carbon dioxide from the absorption tower to generate regeneration gas containing carbon dioxide and water; and a power generation unit provided with the regeneration gas to recover heat from the regeneration gas, and driving a turbine based on the recovered heat to generate power.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a carbon dioxide recovery and power generation system,

The present invention relates to a carbon dioxide recovery and power generation system.

Recently, as the importance of the environment has increased, regulations on carbon dioxide in the atmosphere have become very severe. In particular, with the entry into force of the Kyoto Protocol, global atmospheric residence time and contribution to greenhouse effect, and the reduction of carbon dioxide emissions, which are the largest in total domestic emissions, and the occurrence of carbon dioxide, Is required.

Reduction of carbon dioxide, which is a representative greenhouse gas, is an urgent need to reduce carbon dioxide in power plants. Currently, research is underway on technologies for separating and recovering carbon dioxide. Operation of facilities for separating and recovering carbon dioxide consumes very high energy and it is necessary to utilize it to improve energy utilization efficiency of collection facilities.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a carbon dioxide recovery and power generation system capable of recovering a heat source and separated carbon dioxide consumed for separating and recovering carbon dioxide .

A carbon dioxide recovery and power generation system according to the present invention includes an absorption tower in which an absorbent for absorbing carbon dioxide in exhaust gas is contained, an absorbent for absorbing carbon dioxide from an absorption tower, A regeneration tower for generating regeneration gas containing carbon dioxide and moisture by heating the absorbent to separate carbon dioxide from the absorbent, a regeneration tower for recovering heat from the regeneration gas by supplying the regeneration gas, driving the turbine based on the recovered heat, Unit.

Accordingly, the heat source and the separated carbon dioxide consumed for separating and recovering carbon dioxide can be recovered to produce electric power, and the efficiency of energy use can be increased.

1 is a schematic view showing a carbon dioxide recovery and power generation system according to a first embodiment of the present invention.
2 is a schematic view showing a carbon dioxide recovery and power generation system according to a second embodiment of the present invention.
3 is a schematic view showing a carbon dioxide recovery and power generation system according to a third embodiment of the present invention.
4 is a schematic view showing a carbon dioxide recovery and power generation system according to a fourth embodiment of the present invention.
Figure 5 is a simplified view of the first separator of Figures 2 and 4;
Figure 6 is a simplified view of the second separator of Figures 2 and 4;

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

Example  One

1 is a schematic view showing a carbon dioxide recovery and power generation system according to a first embodiment of the present invention.

As shown in FIG. 1, the carbon dioxide recovery and power generation system includes an absorption tower 100, a regeneration tower 200, and a power generation unit 300.

The absorption tower 100 is provided with an inlet 101 through which exhaust gas is introduced and an absorbent (not shown) for adsorbing carbon dioxide in the exhaust gas is accommodated in the absorption tower 100. The regeneration tower 200 is connected to the absorption tower 100 And an absorbent that absorbs carbon dioxide is provided. The regeneration tower 200 heats the absorbent to separate the carbon dioxide from the absorbent to produce a regeneration gas containing carbon dioxide and moisture.

The power generation unit 300 receives the regeneration gas, recovers heat from the regeneration gas, and drives the turbine 320 based on the recovered heat to generate electricity.

The absorber 100 is described as containing an absorbent for absorbing carbon dioxide in the exhaust gas. However, the present invention is not limited thereto, and it is also possible that the absorbent for absorbing carbon dioxide in the exhaust gas is accommodated therein.

The power generation unit 300 may include a heat exchanger 310. The heat exchanger 310 may be provided in the circulation line 303 where the working fluid circulates. The heat exchanger 310 can exchange heat between the working fluid and the supplied regeneration gas.

 The turbine 320 may be configured to receive the working fluid heated by the regeneration gas in the heat exchanger 310 and to generate electricity by driving the turbine 320.

The power generation unit 300 may be an organic Rankine cycle device. The power generation unit 300 may further include a condenser 340 for condensing the working fluid and a compressor 350 for compressing the working fluid.

The heat exchanger 310, the turbine 320, the condenser 340, and the compressor 350 may be sequentially positioned along the circulation direction of the working fluid on the circulation line 303. For example, the working fluid may be toluene or pentane.

The working fluid may be supplied with heat from the regeneration gas discharged from the regeneration tower 200 by the heat exchanger 310 and then the turbine 320 may be generated to generate electric power through the generator 330.

The working fluid that has passed through the turbine 320 is condensed through the condenser 340 and then flows along the circulation line 303 and may be supplied to the compressor 350. The compressor 350 can compress the working fluid.

The regeneration gas is utilized by the heat exchanger 310 as the power generation unit 300, so that the power generation unit 300 can be configured to produce power.

The carbon dioxide recovery and power generation system according to the present embodiment may further include a first separator 500.

The first separator 500 receives the absorbent absorbed by carbon dioxide and the residual gas which is a gas from which carbon dioxide has been removed from the exhaust gas by the absorbent from the absorption tower 100 to separate the absorbent and the residual gas, (200), and is configured to discharge the residual gas.

For example, the first separator 500 may be a cyclone. The present invention is not limited to a cyclone, and can be applied to any structure that separates an absorbent and a residual gas.

The regeneration tower 200 may be equipped with a thermal supply unit 290 to heat the absorbent. The thermal supply 290 supplies the heat necessary to separate the carbon dioxide from the sorbent. The heat supply unit 290 may be a reboiler, steam, heater, hot water, etc. for supplying heat energy. The heat radiating portion 290 is satisfactory if it is configured to heat the absorbent absorbing carbon dioxide to the regeneration temperature for separating. By the heat supply portion 290, the absorbent can be regenerated and can be moved to the absorption tower 100.

The regeneration tower 200 may further include a fluidizing gas supply (not shown) to smooth the flow of the absorbent. The fluidized gas supply (not shown) may provide a flowing gas to the fluidized gas inlet 210 provided in the regenerator 200. The regeneration tower 200 may be provided with a flow gas outlet 220 for discharging the flowing gas. For example, the flowing gas may be air, carbon dioxide.

The carbon dioxide recovery and power generation system according to the present embodiment may further include a second separator 600. The second separator 600 may be configured to separate carbon dioxide from the absorbent contained in the regeneration tower 200.

The second separator 600 may be provided with a regeneration gas containing absorbent, carbon dioxide, and moisture from the regeneration tower 200.

For example, the second separator 600 may be a cyclone. When the regenerant gas and the absorbent are introduced into the second separator 600, the absorbent can be dropped and re-supplied to the regeneration tower 200, and the regeneration gas can be supplied to the heat exchanger 310.

Through the heat exchanger 310, the regeneration gas is utilized in the power generation unit 300, so that energy can be used more efficiently.

The carbon dioxide recovery and power generation system according to the present embodiment may further include a gas-liquid separator 400. The gas-liquid separator 400 may be configured to receive the regeneration gas cooled by heat exchange in the heat exchanger 310 and to separate carbon dioxide and moisture from the cooled regeneration gas. The regeneration gas which has been heat-exchanged with the working fluid can be condensed and supplied to the gas-liquid separator 400, and the carbon dioxide from which moisture has been removed can be supplied to the regeneration tower 200 through the gas-liquid separator 400. The regeneration tower 200 can be supplied with the carbon dioxide from which moisture has been removed.

For example, a portion of the carbon dioxide from which moisture has been removed in the gas-liquid separator 400 may be supplied to the regeneration tower 200 along the bypass line 420 and the remainder may be supplied to the post-treatment unit 900 to purify, The carbon dioxide can be recovered by compression.

For example, the flowing gas inflow line 211 into which the flowing gas flows from the fluidizing gas supply (not shown) of the regenerator 200 can be communicated with the bypass line 420. A valve (not shown) may be provided at a connection point between the inflow line 211 and the bypass line 420.

By the adjustment of the valve (not shown), the carbon dioxide from which moisture has been removed through the bypass line 420 can be selectively supplied to the flow gas inlet 210.

For example, when the absorbent is in contact with excessive moisture, the active agent is removed by adsorption of the absorbent, active ingredient leaching of the absorbent, micropore blocking due to excessive moisture adsorption, deactivation, Etc. may be generated.

The carbon dioxide from which moisture has been removed through the bypass line 420 is selectively supplied to the flow gas inlet 210 so that the carbon dioxide from which moisture has been removed is supplied to the regeneration tower 200 to cause adhesion of the absorbent by moisture, The absorbent introduced into the regeneration tower 200 from the absorption tower 100 is decomposed by the heat supply part 290 into carbon dioxide and water, In this case, in order to remove moisture in the regeneration tower 200, water removed carbon dioxide is utilized in the regeneration tower 200, so that the regeneration tower 200 does not need an additional device for removing moisture .

The regeneration gas can be recycled to the regeneration tower 200 after being utilized in the power generation unit 300, and energy can be used more efficiently.

For example, when the carbon dioxide recovery and power generation system according to the first embodiment is driven and pentane is used as the working fluid, the temperature of the regeneration gas in the regeneration tower is 250 ° C. to 350 ° C. and the entropy efficiency of the turbine 320 is 92 %. The total pressure (atmospheric pressure operation) of the carbon dioxide recovery and power generation system is 1 bar, the absorption capacity of reactivity of the absorbent used in the absorption tower 100 is 2.5 wt%, and the absorption temperature, which is the temperature of the absorption tower 100, , The regeneration temperature of the gas stream temperature after the second separator 600 is 250 to 350 ° C after the second separator 600 and the total energy consumption required for the collection facility (except the power generation unit) is 4446.3 to 6219.5 MJ / t, and power production = 0.46 ~ 0.49MW.

For example, only the absorption tower 100, the regeneration tower 200, the first separator 500, the second separator 600, and the water separator 400 are disposed without the power generation unit 300, The regeneration gas in the regeneration tower 200 passes through the water separator 400 without passing through the heat exchanger and the water is removed from the water separator 400. [ The carbon dioxide removal rate was 80% or more, the regenerator 200 temperature was 250 ° C, the carbon dioxide purity was 90% or more, the pressure was 1 bar, the absorption capacity was 2.5 wt%, and the absorbed carbon dioxide Temperature = 70 占 폚, regeneration temperature = 250 占 폚, energy consumption = 4446.3 MJ / t.

Example  2

FIG. 2 is a schematic view showing a carbon dioxide recovery and power generation system according to a second embodiment of the present invention, and FIGS. 5 to 6 are schematic views showing first and second separators. Will be described with reference to Fig. 2 and Figs. 5 to 6. Fig.

The carbon dioxide recovery and power generation system according to the second embodiment has some differences in the carbon dioxide recovery and power generation system according to the first embodiment and the first and second separators 500 and 600 and the cooler 700 according to the first embodiment. In the following, the same reference numerals are used for the same constituent elements, and redundant explanations are omitted.

As shown in FIGS. 2 and 5, the first separator 500 includes a first inlet 510 provided with an absorbent absorbing carbon dioxide from the absorption tower 100 and a residual gas, A first lower discharge port 530 disposed below the first discharge port 530 for dropping a predetermined weight or more and a first upper discharge port 520 disposed above the first inlet 510 and discharging the residual gas, have.

The first inlet port 510 and the first upper outlet port 520 and the first lower outlet port 530 may form a first internal flow path communicating with each other. On the outer side of the first internal flow path, a heat insulating member 540 .

The absorption tower 100 and the first inlet 510 may be connected to each other through the first flow path 110. The absorbent and the residual gas adsorbing the carbon dioxide from the absorption tower 100 may be guided to the first inlet 510 have. The first bottom outlet 530 and the regenerator 200 may be connected to each other through the second flow path 120. The first bottom outlet 530 may be connected to the absorbent Can be guided to the regeneration tower 200. For example, the first separator 500 may be a cyclone. The present invention is not limited to a cyclone, and can be applied to any structure that separates an absorbent and a residual gas.

The first separator 500 receives the absorbent absorbed by carbon dioxide and the residual gas which is a gas from which carbon dioxide has been removed from the exhaust gas by the absorbent from the absorption tower 100 to separate the absorbent and the residual gas, (200), and the residual gas can be discharged through the first upper outlet (520).

 The first separator 500 can receive a heat source from the regeneration gas. The first separator 500 may be supplied with heat from the regeneration gas to promote the separation of the absorbent and the residual gas. The heat exchanger 310 may be supplied with the regeneration gas through the first separator 500.

The second separator 600 may be configured to separate the absorbent introduced into the regeneration tower 200 from the regeneration gas (carbon dioxide and water vapor) generated during the regeneration process. 6, the second separator 600 includes a second inlet 610 that receives a regeneration gas containing absorbent, carbon dioxide, and moisture from the regeneration tower 200, and a second inlet 610 that is relatively And a second upper discharge port 620 for discharging the regeneration gas except for the absorbent, which is disposed on the upper portion of the second inlet 610, .

 For example, when the regeneration gas and the absorbent are introduced into the second inlet 610, the absorbent may be dropped through the second lower outlet 630 and re-supplied to the regenerator 200, and the second upper outlet 620 Can be flowed to the first separator 500 provided with the heat retaining member 540.

The absorbent can be regenerated and re-supplied to the regeneration tower 200 by the heat supply unit 290 and the regeneration gas can flow to the heat exchanger 310 through the heat retaining member 540. [

The regeneration gas may be supplied to the heat exchanger 310 after providing heat (to promote separation of the absorbent and residual gas) through the warming member 540.

This is because the heat source of the regeneration gas can be utilized in the first separator 500 and then supplied to the heat exchanger 310.

The flowing gas and the regeneration gas supplied to the regeneration tower 200 may be supplied to the gas-liquid separator 400 after being supplied to the heat exchanger 310 via the second separator 600, the warming member 540, and the like.

The carbon dioxide recovery and power generation system according to the present embodiment may further include a cooler 700. The cooler 700 may be provided with the absorbent regenerated in the regeneration tower 200 and may be cooled and then supplied to the absorption tower 100.

For example, the bypass line 420 may be connected to the inflow line 211 after passing through the cooler 700. The cooler 700 may be equipped with an internal heat exchanger (not shown), and the carbon dioxide separated from the gas-liquid separator may be supplied to the internal heat exchanger through the bypass line 420 and then flow into the inflow line 211 .

The carbon dioxide separated from the gas-liquid separator 400 may be supplied to the internal heat exchanger (not shown) of the cooler 700 through the bypass line 420 to cool the absorbent.

For example, the bypass line 420 may also be connected to the cooler 700 after passing through the absorption tower 100. When the temperature of the absorption tower 100 is 120 ° C, the carbon dioxide separated from the gas-liquid separator 400 is separated into the absorption tower 100 Cooled, and then supplied to an internal heat exchanger (not shown) of the cooler 700. This is because the carbon dioxide separated in the gas-liquid separator 400 is utilized in the absorption tower 100, so that the absorption tower 100 does not need to use an additional cooling fluid.

The regeneration gas is utilized in the power generation unit 300 and then used for cooling the absorbent through the cooler 700 and then supplied to the regeneration tower 200 so that energy can be used more efficiently and the absorbent is cooled , The reproduction efficiency can be increased.

This can improve the purity of carbon dioxide by preventing the adsorption of the absorbent by moisture, the lowering of the physical properties of the absorbent and the generation of side reactions by supplying the carbon dioxide from which moisture has been removed to the regenerator 200.

Example  3

3 is a schematic view showing a carbon dioxide recovery and power generation system according to a third embodiment of the present invention. The carbon dioxide recovery and power generation system according to the third embodiment is different in some respects from the carbon dioxide recovery and power generation system according to the first embodiment and the power generation unit. In the following, the same reference numerals are used for the same constituent elements, and redundant explanations are omitted.

As shown in Fig. 3, the power generation unit 301 may be a supercritical carbon dioxide power generation apparatus. The working fluid may be supercritical carbon dioxide.

The power generation unit 301 may further include a compressor 380 and a heat recovery unit 360. The compressor 380 may be configured to compress supercritical carbon dioxide, which is the hydraulic fluid, and the heat recovery unit 360 is configured to heat-exchange the working fluid discharged from the compressor 380 and the working fluid discharged from the turbine 320 .

The working fluid compressed from the compressor 380 can be preheated by the working fluid discharged after driving the turbine 320 by the heat exchanger 360. [

On the circulation line 303, the heat exchanger 310, the turbine 320, and the compressor 380 can be sequentially positioned along the circulation direction of the working fluid. The working fluid flowing along the circulation line 303 can be supplied with heat from the regeneration gas by the heat exchanger 310 and then driven by the turbine 320 to produce electric power through the generator 330.

The working fluid that has passed through the turbine 320 can be supplied to the condenser 370 via the heat exchanger 360 and the working fluid is condensed and cooled through the condenser 370 and then supplied to the compressor 380 . Flows along the circulation line 303 and can be supplied to the compressor 380. [

For example, when the carbon dioxide recovery and power generation system according to the third embodiment is operated and supercritical carbon dioxide is used as the working fluid, the temperature of the regeneration gas in the regeneration tower is 250 ° C. to 350 ° C. and the entropy efficiency And the power consumption was 0.14 to 0.29 MW. The measured values were as follows: pressure = 1 bar, absorption capacity = 2.5 wt%, absorption temperature = 70 ° C., regeneration temperature = 250 to 350 ° C., energy consumption = 4446.3 to 6219.5 MJ / .

Example  4

4 is a schematic view showing a carbon dioxide recovery and power generation system according to a fourth embodiment of the present invention. The carbon dioxide recovery and power generation system according to the fourth embodiment is different in some respects from the carbon dioxide recovery and power generation system according to the second embodiment and the power generation unit. In the following, the same reference numerals are used for the same constituent elements, and redundant explanations are omitted.

As shown in Fig. 4, the power generation unit 301 may be a supercritical carbon dioxide generator, and the working fluid may be supercritical carbon dioxide. The power generation unit 301 of FIG. 4 may be the same as the power generation unit 301 of FIG.

The supercritical carbon dioxide flowing along the circulation line 303 can be supplied with heat from the regeneration gas by the heat exchanger 310 and then can drive the turbine 320 to generate electric power through the generator 330.

The working fluid that has passed through the turbine 320 can be supplied to the condenser 370 via the heat exchanger 360 and the working fluid is condensed and cooled through the condenser 370 and then supplied to the compressor 380 .

The present invention is not limited to the structure of the power generating units 300 and 301 shown in Figs. 1 to 4, and can be applied to any structure capable of generating electric power.

This is because the heat source consumed for separating and recovering carbon dioxide can generate electric power through the power generation units 300 and 301, thereby improving the efficiency of energy use.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: absorption tower 200: regeneration tower
300, 301: power generation unit 310: heat exchanger
500: first separator 600: second separator
700: Cooling section 900: Postprocessing section

Claims (8)

An absorption tower having an inlet through which exhaust gas is introduced and in which an absorbent for adsorbing carbon dioxide in the exhaust gas is accommodated;
A regeneration tower that receives the absorbent absorbing the carbon dioxide from the absorption tower and heats the absorbent to separate the carbon dioxide from the absorbent to generate a regeneration gas containing the carbon dioxide and moisture;
A power generation unit that receives the regeneration gas, recovers heat from the regeneration gas, and generates power by driving the turbine based on the recovered heat;
Wherein the carbon dioxide recovery and power generation system comprises: The method according to claim 1,
Wherein the power generation unit is provided in a circulation line through which a working fluid circulates and includes a heat exchanger for exchanging heat between the working fluid and the supplied regeneration gas,
Wherein the turbine is operated by receiving a working fluid heated by the regeneration gas in the heat exchanger. The method of claim 2,
Wherein the power generation unit further comprises a condenser for condensing the working fluid and a compressor for compressing the working fluid,
Wherein the heat exchanger, the turbine, the condenser, and the compressor are sequentially positioned along the circulation direction of the working fluid on the circulation line. The method of claim 2,
The power generation unit includes:
A compressor for compressing supercritical carbon dioxide as the hydraulic oil; And
Further comprising a recuperator for exchanging heat between a working fluid discharged from the compressor and a working fluid discharged from the turbine, the supercritical carbon dioxide generating device comprising:
Wherein the heat exchanger, the turbine, and the compressor are sequentially positioned along the circulation direction of the working fluid on the circulation line. The method of claim 2,
The absorbent absorbing the carbon dioxide and the residual gas being the gas from which the carbon dioxide has been removed from the exhaust gas by the absorbent is supplied from the absorption tower to separate the absorbent and the residual gas, Further comprising a first separator for delivering the first liquid,
Wherein the first separator is supplied with heat for promoting the separation of the absorbent and the residual gas from the regeneration gas,
Wherein the heat exchanger is provided with a regeneration gas passing through the first separator.
The method of claim 2,
Further comprising a gas-liquid separator for receiving the regeneration gas cooled by heat exchange in the heat exchanger and separating the carbon dioxide and the water from the cooled regeneration gas,
The regeneration tower is provided with carbon dioxide separated from the gas-liquid separator. The method of claim 6,
Further comprising a cooler for receiving and regenerating the absorbent recovered in the regeneration tower and providing it to the absorption tower,
The cooler may be provided with carbon dioxide separated from the gas-liquid separator and used for cooling the absorbent,
Wherein the regeneration tower is provided with carbon dioxide through the cooler. The method according to claim 1,
Wherein the regeneration tower is provided with a heat supply unit for heating the absorbent.

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