JP5242207B2 - Method for separating and recovering carbon dioxide from blast furnace gas in blast furnace gas utilization process - Google Patents

Description

  The present invention relates to a method for separating and recovering carbon dioxide from blast furnace gas in a process for using blast furnace gas, and relates to a method for separating and recovering carbon dioxide from blast furnace gas while using the blast furnace gas for an iron making process and power generation.

Conventionally, the blast furnace gas discharged from the blast furnace has a pressure of 0.2 to 0.3 MPa even after the dust is removed by the dust collector. Therefore, it is used for power generation using TRT (Top pressure Recovery Turbine). ing. After that, it is used as a fuel gas for heating and power generation in the iron making process.
In recent years, Patent Document 1 discloses an example of a method for generating power by burning blast furnace gas with a gas turbine power generator in order to improve power generation efficiency.

The outline of the prior art will be described with reference to FIG. FIG. 3 is a system diagram of a gas turbine power generator using blast furnace gas as a fuel, that is, a diagram illustrating a method of using the blast furnace gas.
As shown in FIG. 3, the blast furnace gas of about 0.2 to 0.3 MPa, which has been cleaned by removing dust, is stored in the gas holder 8 after being reduced in pressure while generating power in the TRT 5. When the TRT 5 is not operated, the blast furnace gas is depressurized by the pressure reducing valve 6, silenced by the silencer 7, and then stored in the gas holder 8.

  The blast furnace gas stored in the gas holder 8 is branched to the gas turbine power generator 9 side and the heating side in a steelmaking process such as a hot blast furnace and a coke oven (not shown), and the blast furnace gas introduced to the gas turbine power generator 9 side is After being mixed with coke oven gas (COG) (not shown) and the like to increase the amount of heat necessary for gas turbine combustion, the fuel gas compressor 9-1 boosts the pressure from atmospheric pressure, and then the air compressor 9-5 After being mixed with the pressurized air and combusted in the combustor 9-2 and driven by the gas turbine 9-3, heat is supplied to the steam boiler 9-4 to generate superheated steam. -4 is driven to generate electricity.

On the other hand, the blast furnace gas introduced to the heating side in the iron making process is used as a fuel for heating in a hot blast furnace, a coke oven or the like together with a coke oven gas.
As described above, in the conventional blast furnace gas utilization process shown in FIG. 3, the purified blast furnace gas is subjected to power generation by lowering the pressure of the gas at the TRT 5, and then stored in the gas holder 8. The stored blast furnace gas is burned at a reduced pressure and used as a heating fuel in a steelmaking process such as a hot stove or coke oven, while the remaining stored blast furnace gas The gas was boosted and burned by the gas turbine power generator 9 to generate power.

  In recent years, in order to prevent global warming, reduction of carbon dioxide emissions has become an important issue, and various proposals have been made regarding methods for separating and recovering carbon dioxide. As an example, Patent Document 2 discloses a method of separating and recovering carbon dioxide from a by-product gas generated at an ironworks by a chemical absorption method, and after absorbing carbon dioxide from the gas with a chemical absorption liquid, Utilizing or utilizing low-grade exhaust heat generated at steelworks in the process of heating the liquid and separating carbon dioxide, carbon dioxide emitted from large-scale carbon dioxide sources can be efficiently and inexpensively provided by compact equipment. Describes how to separate and recover carbon dioxide to be separated and recovered

JP-A-9-79046 JP 2004-292298 A

However, Patent Document 1 does not disclose any absorption / separation of carbon dioxide in the gas. Therefore, carbon dioxide contained in the blast furnace gas introduced into the heating side in the iron making process through the gas holder 8 and the exhaust gas from the gas turbine after blast furnace gas combustion cannot be treated.
In addition, after the pressure of the blast furnace gas is once reduced to atmospheric pressure, in order to burn the gas turbine 9-3, it is necessary to increase the pressure by providing the fuel gas compressor 9-1. In addition, there is a problem that energy loss occurs when the pressure is increased, and the energy efficiency of the entire facility is lowered.

  Furthermore, since the amount of blast furnace gas discharged from the blast furnace is extremely large, the amount of treatment becomes large. Therefore, in order to heat and regenerate the absorbing solution that has absorbed a large amount of carbon dioxide, the method using low-grade exhaust heat generated in the ironworks disclosed in Patent Document 2 has absolutely no heating energy. It is extremely short. Therefore, in order to process the large amount of blast furnace gas, it is necessary to arrange a new heating means for heating and regenerating the absorbing liquid, and it is difficult to realize it as a practical technique.

  The main object of the present invention is to solve the above-described problems of the prior art and improve the power generation efficiency in a method of generating power by burning a purified blast furnace gas in a gas turbine power generator. New heating to heat and regenerate the absorption liquid together with the large amount of carbon dioxide contained in the blast furnace gas and the exhaust gas from the gas turbine after blast furnace gas combustion without reducing the energy efficiency of the entire facility An object of the present invention is to provide a method for separating and collecting without arranging means.

  The method for separating and recovering carbon dioxide from blast furnace gas in the process of using the blast furnace gas of the present invention introduces blast furnace gas taken out from the blast furnace into an absorption tower, and in the absorption tower, the absorption liquid contains carbon dioxide in the blast furnace gas. A part of the blast furnace gas from which carbon has been absorbed and carbon dioxide has been removed is introduced into an expansion turbine, depressurized, and then stored in a gas holder to be used as a heating fuel in the iron making process, and the carbon dioxide is removed. In addition, the other part of the blast furnace gas is introduced into a blast furnace gas compressor driven by the expansion turbine, boosted, and then introduced into a gas turbine power generator and used as fuel for generating power by high-pressure combustion, The absorption liquid that has absorbed the carbon dioxide in the absorption tower is heated with the heat of the exhaust gas of the gas turbine, the heated absorption liquid is introduced into the regeneration tower, and the absorption liquid is introduced into the regeneration tower from the absorption liquid. Serial dioxide is removed, and wherein the circulating and the absorption liquid removed the carbon dioxide to the absorption column.

In the present invention, the blast furnace gas from the blast furnace is used as a heat source for the iron making process after carbon dioxide is removed in the absorption tower, and also used for power generation as a fuel for the gas turbine power generator.
At this time, the gas consumed by the fuel gas compressor 9-1 is reduced in the gas turbine power generation device 9 by boosting the blast furnace gas sent to the gas turbine power generation device in advance by the blast furnace gas compressor 13, and the power generation amount is reduced. Can be increased. For driving the blast furnace gas compressor 13, energy is used when the blast furnace gas used for the heating fuel in the iron making process is stepped down by the expansion turbine 14. Since the amount of increase in the power generation amount in the gas turbine power generation apparatus is larger than the power generation amount in TRT in the conventional gas utilization method, the energy efficiency can be improved as a whole.

At this time, by installing the absorption tower before the blast furnace gas branches to the expansion turbine and the blast furnace gas compressor, the absorption tower can bring the blast furnace gas to a high pressure before depressurization. While the carbon absorption performance can be maintained high, the absorption tower can be concentrated in one place. Further, since carbon dioxide, which is an incombustible component in the blast furnace gas, is removed, the amount of heat as fuel gas is increased, and the amount of addition of a fuel increasing material such as COG can be reduced.
Further, the exhaust gas from the gas turbine is used to regenerate the absorption liquid used for removing carbon dioxide in the previous absorption tower. Therefore, carbon dioxide can be separated and recovered efficiently.

In the method for separating and recovering carbon dioxide from blast furnace gas in the blast furnace gas utilization process of the present invention, the exhaust gas of the gas turbine power generation device is introduced into a sub-absorption tower, and the absorption liquid in the exhaust gas is introduced into the absorption liquid in the sub-absorption tower. It is desirable to absorb carbon dioxide.
In the present invention, carbon dioxide contained in the blast furnace gas from the blast furnace is absorbed by the absorption tower described above, and carbon dioxide generated by the subsequent combustion of the blast furnace gas in the gas turbine power generator is sub-absorbed. It can be absorbed by the tower and can be efficiently operated by circulating the absorption liquid while increasing the amount of carbon dioxide separated and recovered.

In the method for separating and recovering carbon dioxide from blast furnace gas in the process of using blast furnace gas according to the present invention, the exhaust gas of the iron making process is introduced into the auxiliary absorption tower and merged with the exhaust gas of the gas turbine power generator, and the auxiliary absorption tower It is desirable that the carbon dioxide in the exhaust gas is absorbed by the absorption liquid.
In the present invention, carbon dioxide generated in the iron making process can also be absorbed by the sub-absorption tower, and efficient operation by circulating the absorption liquid can be performed while increasing the separation and recovery amount of carbon dioxide. it can. Further, by mixing the exhaust gas from the gas turbine and the exhaust gas from the iron making process, the gas temperature in the heat exchanger for heating the carbon dioxide absorption liquid can be lowered, and the carbon dioxide absorption liquid is overheated and deteriorated. Can be prevented.

In the method for separating and recovering carbon dioxide from blast furnace gas in the process of using blast furnace gas according to the present invention, when the amount of heat required for heating the absorption liquid is significantly smaller than the amount of heat of the exhaust gas of the gas turbine, the gas As a turbine power generator, a steam boiler that generates high-pressure steam using the heat of the exhaust gas from the gas turbine, a steam turbine that uses high-pressure steam from the steam boiler as power for the gas turbine power generator, and the steam turbine It is desirable to use a device having a condenser for condensing the used steam, and use the heat of the gas turbine exhaust gas and the condensate heat in the condenser for heating the absorption liquid. .
In the present invention, since the condensate heat that has been discarded by the gas turbine power generation device is used for heating the absorption liquid, the efficiency of use of heat generated by the combustion of the blast furnace gas in the gas turbine power generation device is improved. To do.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1A shows a first embodiment of the present invention.
In FIG. 1A, 6 is a pressure reducing valve, 7 is a silencer, 13 is a blast furnace gas compressor, 14 is an expansion turbine 14, and the blast furnace gas pressure reducing means is configured as described above. Reference numeral 10 denotes an absorption tower, 9-4A denotes a heat exchanger for heating a carbon dioxide absorption liquid, and 12 regeneration towers.
In the figure, the arrow B is the high-pressure clean blast furnace gas cleaned by the various dust collectors (not shown) described in the section of the prior art, part of which is branched to the line C and the other part is It is discharged to an arrow G via lines E and F. On the other hand, the flow indicated by arrows L and M indicates the circulation flow of the carbon dioxide absorption liquid. Arrow K is the separated carbon dioxide.
In the following embodiments, the same symbols are used for the same elements to avoid duplication of explanation.

  In the present invention, a blast furnace gas of about 0.2 to 0.3 MPa, which has been cleaned by removing dust, is branched into a line for burning in the gas turbine power generation device 9 and a line C for burning as heating fuel in the iron making process. The blast furnace gas to be combusted as a heating fuel in the iron making process is passed through the expansion turbine 14 to reduce the pressure, and then stored in the gas holder 8 to be used as a heating fuel in a steel making process such as a hot blast furnace or a coke oven (not shown). While being used, the blast furnace gas to be combusted by the gas turbine power generation device 9 is passed through the blast furnace gas compressor 13 driven by the rotation of the expansion turbine 14 to increase the pressure and supplied to the gas turbine power generation device 9. −1, after the pressure is further increased, the gas turbine 9-3 is driven by the combustor 9-2 to generate power. The carbon dioxide absorption liquid heating heat exchanger 9-4A by supplying heat to heat the carbon dioxide absorbing liquid L adsorbed carbon dioxide (or configuration A).

  Further, a blast furnace gas taken out from a blast furnace (not shown) is introduced into the absorption tower 10, the carbon dioxide in the blast furnace gas is absorbed by the absorption liquid in the absorption tower 10, and the dioxide dioxide is absorbed in the absorption tower 10. The absorption liquid that has absorbed carbon is heated by the heat of the exhaust gas of the gas turbine 9-3, the heated absorption liquid is introduced into the regeneration tower 12, and the carbon dioxide is removed from the absorption liquid in the regeneration tower 12. Then, the absorption liquid from which the carbon dioxide has been removed is circulated to the absorption tower (Configuration B).

FIG. 5 is a diagram illustrating the operation and effect of the above-described configuration A. In the present embodiment, the above-described configuration A occurs when the expansion turbine 14 is used to lower the heating fuel in the iron making process. The blast furnace gas used for the fuel of the gas turbine power generation device 9 can be boosted using the expansion energy to be supplied and supplied as the fuel for the gas turbine power generation device 9.
As a result, the power generation amount I in the TRT 5 of FIG. 3 used as a conventional method of using the blast furnace gas is eliminated, but since the blast furnace gas is supplied at a high pressure, the drive required by the fuel gas compressor 9-1 is achieved. Power can be reduced from IV to IV '. The driving force III required for the air compressor 9-5 does not change.

Further, since the total output VI of the gas turbine power generator 9 is constant, the amount of power generated by the gas turbine generator 9-6 increases from II to II ′. This increase is equal to the energy V recovered by the blast furnace gas compressor 13. Since this is larger than the TRT power generation amount I in the conventional method, the power generation amount increases as a whole, and the energy utilization efficiency of the blast furnace gas is improved.
Furthermore, although it is necessary to install the blast furnace gas compressor 13 and the expansion turbine 14 instead of the TRT 5, the fuel gas compressor 9-1 of the gas turbine power generation device 9 can be downsized and stored in the gas holder 8. Since the amount of gas is reduced, the capacity of the gas holder 8 can be reduced, and the equipment cost can be reduced as a whole.

Note that the pressure and flow rate of the cleaned blast furnace gas varies depending on the operation state of the blast furnace, but it is necessary to keep the pressure and flow rate of the blast furnace gas used for gas turbine power generation constant. preferable.
Therefore, the flow rate of the blast furnace gas passing through the blast furnace gas compressor 13 and the expansion turbine 14 is made constant, and the remaining blast furnace gas is passed through the pressure reducing valve 6 to be reduced to atmospheric pressure, and then stored in the gas holder 8. The pressure and flow rate of blast furnace gas used for gas turbine power generation can be kept constant.

  In the present invention, the method of controlling the flow rate of the blast furnace gas passing through the pressure reducing valve 6 is not limited, but the flow rate of the blast furnace gas introduced into the blast furnace gas compressor 13 and the expansion turbine 14 is measured by the flow meter 16. The flow rate introduced into the blast furnace gas compressor 13 and the expansion turbine 14 can be adjusted by adjusting the opening degree of the flow rate adjustment valve 15 so that the flow rate becomes constant.

Returning to FIG. 1A, as the carbon dioxide separation and absorption method applied to the present invention, for example, a chemical absorption method is used, and a chemical absorption solution such as amines is used.
The high-pressure clean blast furnace gas B taken out from the blast furnace and purified is introduced into the absorption tower 10 installed in the previous stage of the pressure reducing means for the blast furnace gas. In the absorption tower 10, the blast furnace gas is brought into contact with a chemical absorption liquid that is a carbon dioxide absorption medium at around 50 ° C., and carbon dioxide in the blast furnace gas is absorbed by the chemical absorption liquid.

Thereafter, a part of the blast furnace gas from which the carbon dioxide has been removed passes through the gas holder 8 and is conveyed to, for example, a coke oven, a heating furnace (not shown) and burned in various iron making processes to be used as a heat source. .
On the other hand, the other part of the blast furnace gas from which the carbon dioxide has been removed is combusted in the gas turbine power generation device 9, and the exhaust gas passes through the heat exchanger 9-4A for heating the carbon dioxide absorption liquid from the chimney to the atmosphere. To be released.
At this time, the absorption liquid that has absorbed the carbon dioxide in the absorption tower 10 is heated to about 120 ° C. in the heat exchanger 9-4A for heating the carbon dioxide absorption liquid by the heat of the exhaust gas of the gas turbine 9-3. Thereafter, carbon dioxide is separated and recovered from the absorption liquid in the regeneration tower 12, and the regenerated absorption liquid is returned to the absorption tower 10 through a return pipe, so that the absorption liquid circulates between the absorption tower 10 and the regeneration tower 12. Can be recycled.
As described above, the exhaust gas from the gas turbine power generation device 9 is used to regenerate the absorption liquid whose heat was used to remove carbon dioxide in the previous absorption tower. Accordingly, carbon dioxide can be separated and recovered efficiently and a large amount of blast furnace gas can be processed without providing new heating means.

The total amount of exhaust gas heat from the gas turbine 9-3 is used for heating the carbon dioxide absorption liquid in the carbon oxide absorption liquid heating heat exchanger 9-4A. It is not necessary to install the turbine 9-7, and it is possible to effectively use energy while simplifying the equipment. In addition, carbon dioxide, which is an incombustible component in the blast furnace gas, is removed before the blast furnace gas is used as fuel, so the amount of heat as the fuel gas is increased and the amount of addition of a fuel increasing agent such as COG (coke gas) is reduced. be able to.
Further, as described above, the carbon dioxide separated and recovered is, for example, compressed and injected into the ground in a supercritical state, so that carbon dioxide discharged into the atmosphere can be greatly reduced.
Further, since the position of the absorption tower 10 is arranged after the various dust collectors for the blast furnace gas, the blast furnace gas is purified and the absorbing solution does not deteriorate.

[Second Embodiment]
FIG. 1B shows a second embodiment of the present invention.
In FIG. 1B, the structural difference of the present embodiment from the first embodiment is that a sub-absorption tower 11 is newly provided after the heat exchanger 9-4A for heating the carbon dioxide absorbent. . The other configuration is the same as that shown in FIG.
The exhaust gas from the gas turbine power generation device 9 comes into contact with the absorption liquid in the sub-absorption tower 11, and after carbon dioxide is removed from the exhaust gas, it is discharged out of the system.
On the other hand, the absorption liquid that has absorbed carbon dioxide is merged with the absorption liquid that has absorbed carbon dioxide in the absorption tower 10, and then the heat of the exhaust gas of the gas turbine is used to heat the carbon dioxide absorption liquid heat exchanger 9-. 4A is heated to around 120 ° C., and carbon dioxide is separated and recovered from the chemical absorption liquid in the regeneration tower 12.

[Third Embodiment]
FIG. 4 shows a third embodiment of the present invention.
In FIG. 4, in addition to the configuration described in FIG. 1B, the exhaust gas N of the iron making process is introduced into the heat exchanger 9-4A for heating the carbon dioxide absorption liquid, and the exhaust gas of the gas turbine power generator 9 is added. It is the point that was merged with. Since the other points are the same as those in FIG. 1B, a duplicate description is omitted.
The exhaust gas L of the iron making process is brought into contact with the absorbing liquid in the sub-absorption tower 11 together with the exhaust gas of the gas turbine power generation device 9, and after carbon dioxide is removed from the exhaust gas, it is discharged into the body. Moreover, by mixing the exhaust gas from the gas turbine and the exhaust gas from the iron making process, the gas temperature in the heat exchanger for heating the carbon dioxide absorption liquid decreases, and the carbon dioxide absorption liquid is overheated and deteriorated. Can be prevented.

[Fourth Embodiment]
FIG. 2A shows a fourth embodiment of the present invention.
In FIG. 2A, 9-4 steam boiler, 9-7 is a steam turbine, 9-8 shows the condenser which condenses the used steam from the said steam turbine 9-7. Two heat exchange pipelines are provided in the steam boiler 9-4. The heat of the exhaust gas from the gas turbine 9-3 generates one of the high-pressure steam I, drives the steam turbine 9-7 to generate electric power, and the other is the absorption tower 10, which is the CO2 in the blast furnace gas. It is a heat exchange pipe for heating the carbon dioxide absorption liquid L which adsorbed carbon dioxide in order to isolate | separate carbon dioxide from the absorption liquid which absorbed carbon.
The method of applying the method for separating and recovering carbon dioxide from blast furnace gas having such a configuration is preferably performed when the amount of heat necessary for heating the absorption liquid is significantly less than the amount of heat of the exhaust gas of the gas turbine 9-7. .

  That is, as the gas turbine power generation device 9, a steam boiler 9-4 that generates a high-pressure steam I using a part of the heat of the exhaust gas of the gas turbine 9-3, and the high-pressure steam from the steam boiler are used as the gas A device having a steam turbine 9-7 used as power for the turbine power generator 9 and a condenser 9-8 for condensing used steam from the steam turbine 9-7 is used to heat the absorption liquid. Uses a part of the heat of the exhaust gas of the gas turbine 9-3 and the condensate heat in the condenser 9-8.

  In the present invention, since the condensate heat previously discarded in the condenser 9-8 constituting the gas turbine power generation device 9 is used for heating the absorption liquid, the gas turbine power generation device 9 uses the blast furnace gas. The utilization efficiency of the heat generated by the combustion is improved.

[Fifth Embodiment]
FIG. 2B shows a fifth embodiment of the present invention.
In FIG. 2B, in addition to the configuration described in FIG. 2A, the sub-absorption tower 11 is provided at the rear stage of the heat exchanger 9-4A for heating the carbon dioxide absorption liquid.
The other configuration is the same as that shown in FIG.
The exhaust gas from the gas turbine power generation device 9 comes into contact with the absorption liquid in the sub-absorption tower 11, and after carbon dioxide is removed from the exhaust gas, it is discharged out of the system.
On the other hand, the absorption liquid that has absorbed carbon dioxide is merged with the absorption liquid that has absorbed carbon dioxide in the absorption tower 10, and then heat exchange for heating the carbon dioxide absorption liquid with the heat of the exhaust gas of the gas turbine 9-3. It is heated to around 120 ° C. in the vessel 9-4A, and carbon dioxide is separated and recovered from the absorbent in the regeneration tower 12.

[Modification]
In addition, this invention is not limited to the structure of the said embodiment, The deformation | transformation etc. in the range which intends to achieve the objective of this invention are included in this invention.
In the embodiment shown in FIGS. 1B and 2B, the absorption liquid in which the carbon dioxide is adsorbed in the sub-absorption tower 11 and the absorption liquid in which the carbon dioxide is adsorbed in the absorption tower 10 are once merged, and then the carbon dioxide absorption liquid is heated. However, the present invention is not limited to this, and from each of the absorption towers, the carbon dioxide absorption liquid heating heat exchanger 9-4A is individually conveyed. Produces the same effect.

  The method for separating and recovering carbon dioxide from blast furnace gas according to the present invention includes a step of generating power by burning purified blast furnace gas in a gas turbine power generator, exhaust gas from blast furnace gas and / or gas turbine after blast furnace gas combustion. It can be used as a process for heating and regenerating an absorbing solution that has absorbed a large amount of carbon dioxide contained therein.

1 is a block diagram showing a first embodiment of the present invention. It is a block diagram which shows 2nd Embodiment of this invention. It is a block diagram which shows 4th Embodiment of this invention. It is a block diagram which shows 5th Embodiment of this invention. It is a block diagram which shows a prior art example. It is a block diagram which shows 3rd Embodiment of this invention. It is a figure which shows the effect | action and effect of the structure A in the said 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dust catcher 2 ... 1st venturi scrubber 3 ... 2nd venturi scrubber 4 ... Dry type dust collector 5 ... TRT (furnace top pressure recovery turbine)
DESCRIPTION OF SYMBOLS 6 ... Pressure reducing valve 7 ... Silencer 8 ... Gas holder 9 ... Gas turbine power generation device 9-1 ... Fuel gas compressor 9-2 ... Combustor 9-3 ... Gas turbine 9-4 ... Steam boiler 9-4A ... Carbon dioxide absorption liquid Heat exchanger for heating 9-5 ... Air compressor 9-6 ... Generator 9-7 ... Steam turbine 9-8 ... Condenser 10 ... Absorption tower 11 ... Sub-absorption tower 12 ... Regeneration tower 13 ... Blast furnace gas compressor DESCRIPTION OF SYMBOLS 14 ... Expansion turbine 15 Flow control valve 16 Flowmeter A ... Blast furnace gas B ... High pressure clean blast furnace gas C ... Fuel gas for heating of iron-making process D ... Coke oven gas E ... Fuel gas for gas turbine power generator F ... Air G ... Exhaust gas H ... Cooling water I ... Steam J ... Off-gas K ... Carbon dioxide L ... Carbon dioxide absorbent that adsorbed carbon dioxide M ... Carbon dioxide absorbent before adsorbing carbon dioxide N ... Exhaust gas from the iron making process

Claims (3)

Blast furnace gas taken out from the blast furnace is introduced into the absorption tower, the carbon dioxide in the blast furnace gas is absorbed into the absorption liquid in the absorption tower,
A part of the blast furnace gas from which the carbon dioxide has been removed is introduced into an expansion turbine, decompressed, stored in a gas holder, and used as a heating fuel for an iron making process,
The other part of the blast furnace gas from which the carbon dioxide has been removed is introduced into a blast furnace gas compressor driven by the expansion turbine, boosted, and then introduced into a gas turbine power generator for high-pressure combustion to generate power. Used as fuel,
The absorption liquid having absorbed the carbon dioxide in the absorption tower is heated with the heat of the exhaust gas of the gas turbine, the heated absorption liquid is introduced into the regeneration tower, and the carbon dioxide is absorbed from the absorption liquid in the regeneration tower. A method for separating and recovering carbon dioxide from blast furnace gas in a blast furnace gas utilization process, wherein the absorbing liquid from which the carbon dioxide has been removed is circulated to the absorption tower. In the method for separating and recovering carbon dioxide from blast furnace gas in the blast furnace gas utilization process according to claim 1,
The exhaust gas from the gas turbine power generator is introduced into a sub-absorption tower, and the carbon dioxide in the exhaust gas is absorbed into the absorption liquid in the sub-absorption tower. Carbon separation and recovery method. In the method for separating and recovering carbon dioxide from blast furnace gas in the blast furnace gas utilization process according to claim 1 or 2,
As the gas turbine power generator, a steam boiler that generates high-pressure steam using the heat of exhaust gas from the gas turbine, a steam turbine that uses high-pressure steam from the steam boiler as power for the gas turbine power generator, and the steam Using a device having a condenser for condensing used steam from a turbine, and utilizing a part of the heat of the exhaust gas of the gas turbine and the heat of the condenser for heating the absorption liquid, A method for separating and recovering carbon dioxide from blast furnace gas in the process of using blast furnace gas.

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