JP2007309315A - Method for concentrating carbon dioxide present in exhaust gas discharged from a power plant - Google Patents

Abstract

The present invention comprises a number of gas turbines including an inlet gas turbine (10 ₁ ) and at least one additional gas turbine (10 ₂ , 10 ₃ ), said turbine burning a mixture of oxidant and fuel. A method for concentrating carbon dioxide (CO ₂ ) present in exhaust gas discharged from a power plant to be compressed, comprising compressing an oxidant in the form of air with an inlet gas turbine (10 ₁ ), and the inlet gas turbine And the step of burning the air and fuel and the step of removing the exhaust gas generated by the combustion from the gas turbine.
According to the present invention, this method supplies at least one additional gas turbine (10 ₂ , 10 ₃ ) with an oxidant such as exhaust gas generated by the inlet gas turbine, and the additional gas turbine. A step of obtaining an exhaust gas having a low oxygen content and a high CO ₂ concentration at the outlet of
[Selection] Figure 1

Description

The present invention relates to a method for concentrating carbon dioxide (CO ₂ ) present in exhaust gas discharged from a power plant equipped with a large number of gas turbines.

The present invention relates more particularly to the field of capturing carbon dioxide (CO ₂ ) emitted from these gas turbines.

  It is known to use plants with multiple gas turbines for power generation. These gas turbines typically include an oxidizer compressor, a combustion chamber, and an expander. These turbines can simultaneously generate hot exhaust gas for generating steam by passing through a steam generator and mechanical work for driving any device, especially a generator. The steam produced by each generator is combined to create a steam stream that is then sent to a high capacity steam turbine, which then drives a high power generator by mechanical action. The electricity generated by each generator is used as a single unit or independently.

  Generally, ambient air is supplied to the compressor of each gas turbine. Thereafter, this air is sent to the combustion chamber in a compressed state. The combustion chamber also accepts fuel in the form of natural gas and forms a fuel mixture. The fuel mixture is then burned.

  In this configuration, the ambient air supplied to the compressor must be introduced in large quantities not only for combustion in the combustion chamber, but also for cooling various compressor elements such as vanes. Therefore, although the exhaust gas exiting the combustion chamber contains a large amount of oxygen, this oxygen is discharged into the atmosphere without being used.

Natural gas is the most commonly used fuel to supply the combustion chambers of these gas turbines. This is because it is generally accepted that the ratio of CO ₂ generated by the combustion of this gas is lower than that generated by other fuel energy sources called “fossil fuels” such as coal or liquid hydrocarbons. is there. Moreover, such gaseous fuels can be liquefied and easily mass transported to any development site and used there as needed.

  High-temperature exhaust gas is generated by the combustion of the fuel mixture. This high-temperature exhaust gas is sent to the expander, and this is driven and rotated to start the generator connected thereto. Next, the exhaust gas at the outlet of the expander is sent to a heat exchanger in the steam generator, and the liquid circulating there is converted into steam. After the heat exchange, the exhaust gas is optionally cooled in advance and discharged, for example, from the chimney into the atmosphere. The steam generated by the steam generator is sent to a steam turbine connected to a generator.

  Such a cycle, known as GTCC (Gas Turbine Combined Cycle), can also be referred to as a cogeneration turbine and provides the advantage of an electrical efficiency of approximately 60%.

However, the main drawback of this known plant is that for each turbine, exhaust gases with a low carbon dioxide (CO ₂ ) concentration are discharged into the atmosphere. This CO ₂ is harmful to the environment. This is because CO ₂ has been proven to be responsible for the greenhouse effect and global warming observed for decades.

In order to overcome these drawbacks, it is important to use tools (methods and apparatus) that can capture CO ₂ before it is discharged into the atmosphere. This can reduce the greenhouse effect slightly for years to come.

In the field of gas turbines, one known solution is to capture the CO ₂ present in the flue gas.

  The capture methods and equipment used are generally based on cryogenic engineering, absorption by chemical or physical means such as adsorption means on molecular sieves, or the use of membranes, more particularly gas separation membranes.

As an example, CO ₂ absorption methods using physical or chemical solvents can be used, as described in more detail in patent applications, EP 0,744,987 and WO 00 / 57,990. The absorbent solutions described include, for example, primary amines such as MEA, DGA and DIPA, secondary amines such as DEA, and tertiary amines such as MDEA.

However, this method is difficult to achieve in view of the large amount of exhaust gas that must be treated and the low CO ₂ partial pressure in the exhaust gas. Furthermore, when the exhaust gas is exhausted, there is a large amount of residual oxygen in the exhaust gas, and the presence of such oxygen significantly hinders the capture of CO ₂ , especially when using reactive chemical solvents such as amines. Furthermore, it is necessary to provide a CO ₂ capture device in each gas turbine, which not only makes the plant more complex but also significantly increases its cost.

The present invention intends to enrich the CO ₂ for the purpose of capturing the CO ₂ emitted by these gas turbines and reducing the emission of CO ₂ into the atmosphere as much as possible.

Accordingly, the present invention comprises a number of gas turbines including an inlet gas turbine and at least one additional gas turbine, the turbine being present in exhaust gas discharged from a power plant that burns a mixture of oxidant and fuel. A method of concentrating carbon dioxide (CO ₂ ), wherein the following steps are performed:
Compressing the oxidant in the form of air in the inlet gas turbine,
The stage of combustion of this air and fuel in this inlet gas turbine,
The stage of removing the exhaust gas generated by this combustion from this gas turbine,
Supplying at least one additional gas turbine with an oxidizing agent such as exhaust gas generated by the inlet gas turbine, and obtaining an exhaust gas having a low oxygen content and a high CO ₂ concentration at the outlet of the additional gas turbine; To a method characterized by

  If at least two additional gas turbines are provided, the method includes supplying one of the additional gas turbines with an oxidant, such as exhaust gas generated by the inlet gas turbine, and said one of the additional turbines. Supplying an oxidant such as exhaust gas generated by the group to the other one of the additional gas turbines may be included.

  The method can include cooling the exhaust gas before supplying the exhaust gas to the additional gas turbine.

  The method can include passing the exhaust gas exiting the gas turbine through a steam generator.

  The method can include performing catalytic combustion of exhaust gas and fuel in a steam generator such that steam overgeneration occurs.

  The method can include mixing the exhaust gas exiting the generator and the exhaust gas supplied to at least one of the gas turbines.

  The method can include mixing the exhaust gas exiting the generator and the air supplied to the inlet gas turbine.

The method can include capturing CO ₂ at the heat generator outlet.

The method may include capturing CO ₂ at the outlet of the compressor of at least one additional gas turbine.

In configurations where at least one of the gas turbines includes a two-stage compressor, the method may include capturing CO ₂ at the compressor first stage outlet.

The present invention comprises a number of gas turbines including an inlet gas turbine and at least one additional gas turbine, wherein the turbine burns a mixture of oxidant and fuel,
The inlet gas turbine comprises means for taking in air as an oxidant;
It also relates to a power plant characterized in that the at least one additional gas turbine comprises means for taking in the exhaust gas leaving the inlet gas turbine as oxidant.

  This plant can be equipped with exhaust gas cooling means.

  Other features and advantages of the present invention will become apparent from the following description, given by way of non-limiting example, with reference to the accompanying drawings.

  FIG. 1 schematically shows a gas turbine plant used as a generator.

The plant is equipped with at least two gas turbines or combustion turbines. Here, three turbines 10 ₁ to 10 ₃ are arranged in sequence. Each turbine, as is known per se, includes a compressor 12 ₁ to 12 ₃ having at least one compression stage, a combustion chamber 14 ₁ to 14 ₃ , and said compressor and generator 18 ₁ to 18 ₃ etc. Expanders 16 ₁ to 16 ₃ for supplying energy necessary for driving the electricity generating means are provided. In the following description of the present specification, when viewed in right 1 from the left, the first turbine 10 ₁ is referred to as the inlet gas turbines, referred to as additional gas turbine turbine of the other two groups. The third turbine ₁₀₃ is referred to as a terminal additional gas turbine, all arranged another gas turbine 10 ₂ between the inlet gas turbine and terminal additional gas turbine, an intermediate additional gas turbine.

From the steam generator 20 ₁ 20 ₃ or the evaporator is associated with each gas turbine. For the described embodiment, the evaporator 20 _3, as long as it contains heating means such as a catalytic combustion chamber to which the fuel is supplied (not shown), an evaporator 20 ₃ accompanying the gas turbine 10 ₃ excess steam It is a generator (steam surgenator). This fuel may be the same as the fuel supplied to the combustion chamber of the turbine. This has the effect of substantially increasing the amount of steam that the evaporator produces. Of course, all or part of the evaporator may be an excess steam generator without departing from the scope of the present invention. In addition, an exhaust gas cooling exchanger or cooler is associated with all or part of the evaporator to cool the exhaust gas leaving the evaporator. In the illustrated example, only the inlet turbine and the intermediate turbine are provided with the cooling exchangers 22 ₁ and 22 _2, but the end turbine can also be provided with a cooling exchanger. In addition, a water condenser / recuperator (not shown) may be provided between the cooler and the inlets of the expanders 12 ₂ and 12 ₃ . Thereby, before supplying exhaust gas to a turbine, the water in it can be made not to exist.

  The plant also includes an expander 24 through which the vapor from the evaporator flows. This expander is called a steam turbine and drives the generator 26 to rotate. The steam turbine 24 is advantageously a condensing type. This allows the vapor flowing therethrough to be converted to a liquid and then returned to the evaporator, where it can be converted to vapor.

In operation, an oxidizer, typically air at ambient pressure, is supplied to the inlet of the compressor 12 ₁ of the gas turbine 10 ₁ and compressed. Then, this compressed air is sent to the combustion chamber 14 ₁ via the pipe line 28 ₁ . In the combustion chamber, the compressed air is mixed with a liquid or gaseous fuel supplied via a conduit 30. In this example, the fuel used is a gaseous fuel, in this case natural gas. The mixture thus formed burns in the combustion chamber and generates high-temperature exhaust gas. This is sent to the inlet of the expander 16 ₁ via the pipe line 32 ₁ . This exhaust gas rotates the turbine, which in turn rotates the compressor 12 ₁ and the generator 18 ₁ . Then the expanded high-temperature exhaust gas of substantially atmospheric pressure, is discharged to the inlet of the evaporator 20 ₁ via the line 34 from the turbine. In this evaporator, heat exchange is performed between a liquid such as water supplied through a pipe line 36 connected to the condensing turbine 24 and exhaust gas flowing therethrough. The vapor thus generated flows out of this evaporator via line 38. The exhaust gas flows out at a temperature lower than the inlet temperature through the pipe line 40 provided with the cooler 22 ₁ . The exhaust gas is cooled to a temperature near the ambient temperature by passing through a cooler in which an arbitrary cooling fluid such as ambient air represented by an arrow 42 in the figure scavenges. The cooled flue gas contains oxygen and CO ₂ significant proportion. This exhaust gas is sent to the inlet of the compressor 12 ₂ of the intermediate gas turbine 10 ₂ where it is compressed. The compressed exhaust gas is supplied to the combustion chamber 14 ₂ as an oxidant via the pipe line 28 ₂ . The exhaust gas is then mixed with the natural gas supplied via the conduit 30 and results in the combustion of the fuel mixture thus obtained. This combustion can consume most of the oxygen present in the exhaust gas supplied to this combustion chamber, and the hot exhaust gas obtained from this combustion has a higher ratio than the gas supplied to this combustion chamber. Contains CO ₂ .

As described above with respect to the inlet gas turbine 10 ₁ , the hot exhaust gas from the combustion chamber is carried by the line 32 ₂ and flows through it while driving and rotating the expander 16 ₂ , thus in turn the generator. 18 ₂ is driven and rotated. The expanded exhaust gas reaches the evaporator 20 ₂ to which the liquid is supplied via the pipe 44 and generates steam. The vapor exits the evaporator via line 46. The cooled exhaust gas exits the evaporator 20 ₂ , flows through the cooler 22 ₂ , reaches the inlet of the compressor 12 ₃ of the end gas turbine 10 ₃ through the pipe line 48 at a temperature near ambient temperature. To do. As described with respect to the inlet gas turbine 10 ₁ and the intermediate gas turbine 10 ₂ , in this respect, the compression cycle of the compressor 12 ₃ , the combustion cycle of the combustion chamber 14 ₃ , and the expansion cycle of the turbine 16 ₃ , and the generator 18 ₃ The power generation cycle is repeated. Thereby, in the pipe lines 50 at the outlets of the expanders 10 ₁ and 10 ₂ , exhaust gas having a low oxygen ratio and a high CO ₂ content is generated. This high-temperature and ambient-pressure exhaust gas is sent to the evaporator 20 ₃ , and the liquid circulating in the pipe line 36 also flows through this evaporator. As a result, steam can be generated, and this steam is discharged via the pipe 52.

The cooled exhaust gas leaving the evaporator via line 54 contains a high proportion of CO _{2 at a} pressure close to atmospheric pressure, but has a low oxygen content. This exhaust gas is then sent to any CO ₂ capture means as described above. This can improve and simplify this CO ₂ capture. The capture of CO ₂ can be done at ambient temperature. Moreover, the proportion of oxygen present in the exhaust gas is not so high as to prevent this capture, especially when reactive chemical solvents are used.

Of course, if it is desired to further reduce the proportion of oxygen in the exhaust gas at the outlet 54, the exhaust gas can be post-combusted in the evaporator 20 ₃ before being sent to the CO ₂ capture means. Therefore, natural gas is sent to the evaporator 20 ₃ via the gas line 30, and combustion, preferably catalytic combustion, is performed using oxygen contained in the exhaust gas flowing through the evaporator. Thereby, it is possible to advantageously realize the excessive generation of steam in the pipe line 52.

  Steam circulating in lines 38, 46 and 52 is sent to the inlet of steam expander 24 and flows through it while driving and rotating about its axis of rotation. This rotation also drives the generator 26 to which the turbine is connected.

Thus, the method described above provides the advantage of being simple, robust, efficient and inexpensive since it does not require special or expensive equipment to perform the CO ₂ enrichment step prior to capture.

  Based on the plant described above, the Applicant performed a simulation. The results are described below.

  In this simulation, three General Electric type 7 gas turbines (GE frame 7) were used. Each turbine was connected to other turbines according to the layout of FIG.

At a temperature of 30 ° C. and a relative humidity of 50%, atmospheric pressure air is supplied to the compressor 12 ₁ of the inlet gas turbine 10 ₁ at a flow rate of 924 t / h (tons / hour) and an oxygen concentration of 21% by volume. Next, this compressed air is supplied to the combustion chamber 14 ₁ . In this combustion chamber, the compressed air is mixed with gaseous fuel, here methane gas, which is injected into this combustion chamber via a conduit 30 at a flow rate of 15 t / h. After burning the fuel mixture, the exhaust gas, while driving the expander 16 _one rotation, it flows through it. At the outlet of the expander, the exhaust gas has a temperature of about 530 ° C. and a pressure of 1.2 absolute bar. This high-temperature exhaust gas has a flow rate of 939 t / h and contains about 14.5% by volume of oxygen and 3% by volume of CO ₂ . The generator 18 ₁ driven by the expander 16 ₁ can obtain electric power of approximately 76 MW (megawatts).

The exhaust gas is sent to the evaporator 20 _1, in this evaporator, a liquid such as water circulated therethrough to convert the conduit 38 to 260 ° C. and 20 bar steam 160t / h. At the outlet of the evaporator, the exhaust gas has a temperature of about 100 ° C. This exhaust gas is sent to a cooler 22 ₁ and exits at a temperature of 30 ° C. and an oxygen concentration of about 15% by volume. After removing water contained in the exhaust gas (condensed water: about 19 t / h), the exhaust gas is supplied to the compressor 12 ₂ of the turbine 10 ₂ . In the combustion chamber 14 ₂ , methane gas 15 t / h is mixed with the compressed exhaust gas. The hot exhaust gas resulting from the combustion flows through the expander 16 _2, leaving there a flow rate 935t / h and a temperature of about 530 ° C.. The exhaust gas at a pressure of 1.2 absolute bar then contains 8.7% oxygen and 6.1% CO _{2 by} volume.

Similarly, the exhaust gas is sent to the evaporator 20 _2, to produce steam 160t / h of 260 ° C. and 20 bar in line 46. In this heat exchange, the exhaust gas can be cooled to a temperature of about 100 ° C. The exhaust gas is then sent to the cooler 22 ₂ where it reaches a temperature of 30 ° C. After removing the water contained in the exhaust gas (condensed water of about 26 t / h), the exhaust gas is sent to the compressor 12 ₃ of the gas turbine 10 ₃ . At the inlet of the compressor 12 _3, the flow rate of the exhaust gas is 909t / h, the oxygen concentration is about 9% by volume. As before, methane gas (flow rate 15 t / h) is mixed with this gas in the combustion chamber 14 ₃ to generate high-temperature exhaust gas. The hot exhaust gas then flows through the expander 16 ₃ while driving and rotating it. Under the rotational thrust of the expander 16 ₃ , the generator 18 ₃ generates about 75 MW of power.

At the outlet of the expander 16 _{3 and} the inlet of the evaporator 20 ₃ , the flow rate of the exhaust gas treated in the line 50 is 924 t / h at about 530 ° C. and a pressure of 1.2 absolute bar. The CO ₂ contained in this exhaust gas is approximately 9.3% by volume, while the oxygen concentration is approximately 2.7% by volume.

In order to further reduce the presence of oxygen in the exhaust gas as much as possible and to increase the CO ₂ concentration in the exhaust gas that is finally treated, it is advantageous to post-combust this exhaust gas.

More specifically, this after-combustion is performed in the evaporator 20 ₃ by catalytic combustion supplying methane 5 t / h via the line 30. This post-combustion can produce steam 320 t / h at 260 ° C. and a pressure of 20 bar containing 1000 ppm oxygen and 10.5% CO _{2 at} the evaporator outlet. This 320 t / h of steam can be added to 160 t / h from line 38 and 160 t / h from line 46 to deliver 640 t / h of steam to the inlet of the steam expander 24. Thus, the steam can generate about 140 MW of electric power through the rotation of the turbine and the rotation of the generator 26 connected thereto.

  Therefore, the total power generated by this plant is approximately 365 MW (75 MW × 3 + 140 MW). On the other hand, since about 50 t / h of methane corresponding to 645 MW of energy is consumed, the efficiency is about 56%.

According to the present invention, the amount of generated exhaust gas is reduced to approximately 929 t / h. On the other hand, in the prior art plant, about 2822 t / h of exhaust gas is generated. Furthermore, the exhaust gas from the prior art plant containing about 13.5% oxygen and only 4% CO ₂ has a low oxygen concentration while the CO ₂ concentration is high.

  The table below summarizes the results obtained for the plant configuration described above.

  FIG. 2 shows one variation of the plant of FIG. Accordingly, elements common to the two figures have the same reference numerals.

This modification differs from FIG. 1 in that a pre-CO ₂ capture stage is provided at the level of the end gas turbine 10 ₃ before capturing CO ₂ at the outlet 54 of the evaporator 20 ₃ .

That is, a known CO ₂ capture device 56 is provided between the outlet of the compressor 12 ₃ of this gas turbine and the inlet of the combustion chamber 14 ₃ . As a non-limiting example, the device can be one of those described above.

Operation of such variations plants, to the stage of compressed gas exits the compressor 12 ₃ are the same as those of the above-described operation. This compressed exhaust gas then flows through the capture device 56 where the CO ₂ is separated from the exhaust gas. After most of the CO ₂ is discharged and removed via the flow path S to any storage and / or processing means, the exhaust gas is supplied to the combustion chamber 14 ₃ and introduced via the conduit 30. Combustion is performed using the natural gas. The exhaust gas generated from this combustion is sent to the expander 16 ₃ . Exhaust gas is sent to the evaporator 20 ₃ out of here. After this configuration, proceed with the steps described for FIG. The generated steam is conveyed to the steam turbine 24 via the pipe line 52, and in this case, the exhaust gas containing a lower ratio of CO ₂ than that in FIG. 1 is discharged via the pipe line 54. Next, the exhaust gas having a low CO ₂ content is either processed by another CO ₂ capture device or discharged into the atmosphere from a chimney (not shown).

The variant of FIG. 3 is characterized in that a capture device 56 in the gas turbine 10 ₃ is arranged between the two compression stages 12 _3A and 12 _3B of this turbine.

During operation of the plant, the exhaust gas flowing through line 48, (in the range between about 2 bar and about 10 bar) by the first compression stage 12 _3A after being compressed to a first pressure, the capture device 56 Flowing through. The exhaust gas is recompressed to a pressure generally in the range between about 10 bar and about 40 bar in the second compression stage 12 _3B after removing most of its CO ₂ and exhausting it through the flow path S. The This recompressed exhaust gas is then sent to the combustion chamber 14 ₃ to allow combustion using natural gas introduced via line 30. As already described with respect to FIG. 2, after this point, the process generates steam in line 52 and directs the low CO ₂ ratio exhaust gas to another CO ₂ capture device via line 54. Or proceed to exhaust from the chimney to the atmosphere.

In the variant of FIG. 4, the gas turbine 10 ₃ is provided with a CO ₂ capture device 56 arranged between the outlet of the compressor 12 ₃ and the combustion chamber 14 ₃ as already described for FIG.

In this variant, the exhaust gas circulating in the outlet line 54 at the outlet of the evaporator 20 ₃ is reinjected in whole or in part into at least the compressor inlet of the end gas turbine 10 ₃ via the recirculation line 58. . This recirculated exhaust gas is advantageously cooled by passing through a heat exchanger 60 so that it can be cooled to a temperature close to that of the exhaust gas entering the compressor via line 48.

Therefore, the recirculated exhaust gas is mixed in the compressor with the exhaust gas carried by the pipe 48 and then sent to the CO ₂ capturing device 56. The compressed exhaust gas from which most of CO ₂ has been removed is supplied to the combustion chamber 14 ₃ from the outlet of the apparatus, and the gas supplied through the pipe line 30 is combusted. Similarly, operation of the subsequent plant from this point proceeds as already described for the other figures.

It is also possible to recirculate the exhaust gas from the line 54 in whole or in part to the intermediate turbine 10 ₂ and / or the compressor inlet of the inlet turbine 10 ₁ .

  The present invention is not limited to the described embodiments, but includes any variations or equivalents.

It is the schematic which shows the plant provided with the gas turbine by this invention. It is a figure which shows the 1st modification of the plant by invention of FIG. It is the schematic which shows the 2nd modification of this invention. It is a figure which shows the 3rd deformation | transformation.

Claims (12)

A number of gas turbines including an inlet gas turbine (10 ₁ ) and at least one additional gas turbine (10 ₂ , 10 ₃ ), said turbine being discharged from a power plant that burns a mixture of oxidant and fuel; A method for concentrating carbon dioxide (CO ₂ ) present in exhaust gas, wherein the following steps are performed:
Compressing the oxidant in the form of air in the inlet gas turbine (10 ₁ ),
Combusting the air and the fuel in the inlet gas turbine;
Removing the exhaust gas generated by the combustion from the gas turbine;
An oxidant such as the exhaust gas generated by the inlet gas turbine is supplied to at least one of the additional gas turbines (10 ₂ , 10 ₃ ), and the oxygen content is low and the CO ₂ concentration is low at the outlet of the additional gas turbine. A method for concentrating carbon dioxide present in exhaust gas, characterized by comprising a step of obtaining exhaust gas having a high value. At least two additional gas turbines are provided;
Supplying one of the additional gas turbines (10 ₂ ) with an oxidant such as the exhaust gas produced by the inlet turbine (10 ₁ );
Characterized in that it comprises a step of supplying an oxidizing agent such as the exhaust gas wherein the 1 group of additional turbine (10 ₂₎ is generated in addition to the 1 group (10 ₃₎ of the additional gas turbine, in claim 1 The method described. The method according to claim 1, characterized in that it comprises the step of cooling the exhaust gas before supplying it to an additional gas turbine (10 ₂ , 10 ₃ ). The method according to claim 1, comprising passing the exhaust gas leaving the turbine through a steam generator (20 ₁ , 20 ₂ , 20 ₃ ). The method according to claim 4, characterized in that it comprises the catalytic combustion of the exhaust gas and fuel in a steam generator (20 ₃ ) so that an excess of steam is generated. 6. The method according to claim 4, further comprising the step of mixing the exhaust gas leaving the generator (20 ₃ ) with the exhaust gas supplied to at least one of the gas turbines (10 ₂ , 10 ₃ ). The method described. 6. The method according to claim 4, comprising mixing the exhaust gas leaving the generator (20 ₃ ) with the air supplied to the inlet gas turbine (10 ₁ ). the method of. Characterized in that it comprises a step of capturing CO ₂ in the heat generator outlet, the method according to any one of claims 4 7. From the step of capturing CO ₂ at the outlet of at least one compressor (12 ₃ , 12 _3A , 12 _3B ) of the gas turbine (10 ₁ , 10 ₂ , 10 ₃ ) 9. The method according to any one of items 8. At least one of the gas turbines includes a two-stage compressor (12 _3A , 12 _3B ),
Characterized in that it comprises a step of capturing CO ₂ at the outlet of the first stage of the compressor (12 _3A), The method of claim 9. A power plant comprising a number of gas turbines including an inlet gas turbine (10 ₁ ) and at least one additional gas turbine (10 ₂ , 10 ₃ ), wherein the turbine burns a mixture of oxidant and fuel. ,
The inlet gas turbine (10 ₁ ) comprises means for taking in air as oxidant;
A power plant characterized in that at least one of the additional gas turbines comprises means (34, 40, 44, 48) for taking in the exhaust gas leaving the inlet gas turbine (10 ₁ ) as an oxidant. 12. The power plant according to claim 11, further comprising means (22 ₁ , 22 ₂ , 58) for cooling the exhaust gas before the exhaust gas is supplied to the gas turbine.

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