JPH04191418A - Carbon dioxide (co2) recovering power generation plant - Google Patents

Abstract

PURPOSE:To reduce power loss of an oxygen (O2) producing device and prevent generation of poisonous gas by supplying pure O2 produced by the oxygen (O2) producing device directly to a combustor by means of a pressing compressor, and thereby improving recovery ratio of carbon dioxide (CO2) gas. CONSTITUTION:A pressing compressor 12 is provided on a rear step of an O2 producing device 11. The thus compressed O2 is supplied directly to a combustor 3. The carbon dioxide (CO2) suctioned into a compressor 1 is compressed, and a part thereof is supplied to a gas turbine 2 through a turbine blade cooling gas extracting line 9, and the remainder is introduced to the combustor 3. Pure oxygen (O2) produced by the producing device 11 is compressed by the pressing compressor 12 and introduced to the combustor 3, mixed with fuel and carbon dioxide (CO2) for combustion, bringing about high temperature gas. The high temperature gas is sent to the gas turbine 2 for expansion, and to be a power source of a generator 4 and the compressor 1. Exhaust gas of the gas turbine 2 is thermally utilized for steam production in a heat-recovery boiler 5, cooled by an exhaust gas condenser 8, and circulated to the compressor 1 as suction gas.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention aims at improving the replenishment position of CO! Regarding recovery power generation plants.

Conventional technology Figures 2 to 4 show CO2 emissions from three different gas turbine combined cycle plants that have been used in the past.
The system of the recovery power generation plant is shown.

First, in Fig. 2, 1 is a compressor, 2 is a gas turbine,
3 is a combustor, 4 is a generator, 5 is an exhaust heat recovery boiler, and 6 is a chimney.

In the above configuration, the air sucked into the compressor 1 is compressed, a part of which is extracted via the extraction line 7 for cooling the blades of the gas turbine 2, and the rest is extracted from the combustor 3.
The combustion process is assisted by the combustion process, which becomes high-temperature gas and is passed through the gas turbine 2.
It expands and becomes the driving power for the generator 4 and compressor 1.

The gas discharged from the gas turbine 2 is used as a heat source for steam generation in the exhaust heat recovery gas boiler 5, and then is discharged into the atmosphere from the chimney 6 without being recovered. in this case,
The released gas components are nitrogen gas (hereinafter referred to as Nt) and C.
The concentration of O and CO is about 5%.

Next, the one shown in Figure 3 is called the oxygen-enriched combustion method, CO! In the recovery power generation system, the same elements as in FIG.
is a C Ot gas separation and recovery device placed after the condenser 8. Further, 10 is a circulation system for injecting Co2+N and gas from the condenser 8 into the compressor 1, and 02 produced by the 02 production apparatus 11 is injected into the compressor 1 through this circulation system 10.

According to the above configuration, the gas discharged from the gas turbine 2 is used to generate steam in the exhaust heat recovery boiler 5, and then is cooled in the exhaust gas condenser 8 to remove moisture, and the gas is used in the circulation system.
It passes through O and is injected into the compressor 1 again.

In this oxygen-enriched combustion method, the gas discharged from the gas turbine 2 consumes 02 when burned in the combustor 3, and then water is removed in the exhaust gas condenser 8, so that
A gas whose main components are O2 and N2 circulates. Since the 02 production device (oxygen enrichment device) 11 is provided at the inlet of the compressor 1, the 0.02. The compressor 1 constantly maintains the suction gas of the compressor 1 in a parallel state by replenishing the dense air to compensate for the 02 consumed by combustion.

This 02 manufacturing apparatus 11 requires relatively low power because the 02 concentration may be low. In addition, if 02 is replenished and combustion continues, the system pressure will rise, so CO will be released as surplus gas.
2 is recovered by a separation and recovery device 9. The concentration of this surplus gas is about 50% when the supply 02 concentration is 70%, and requires relatively large power for separation and recovery.

In addition, due to thermal combination, the N2 component becomes a nitrate compound (hereinafter referred to as NOx
) occurs.

Next, what is shown in Figure 4 is the C
In the O2 recovery power generation system, the equipment arranged in the circulation system is exactly the same as the oxygen-enriched combustion method described above, but in this method, O2 is used as a replenishment method for O2 consumed in combustion.
The difference is that pure 02 from the manufacturing device 11 is supplied to the inlet of the compressor 1.

In this method, the power consumption of the 02 manufacturing device 11 is large, and the working fluid of the gas turbine after combustion is mainly CO2, and the CO2 concentration of the surplus gas 2 is approximately 8.
It is about 3%.

Problems to be Solved by the Invention However, the above conventional example has the following drawbacks.

That is, according to the gas turbine combined system shown in FIG. 2, since the CO2 concentration of the exhaust gas is about 5%, a large amount of power is required to separate and recover CO2.

Furthermore, according to the oxygen-enriched combustion method shown in Fig. 3, the supplementary gas is O! Since the air has a high concentration, the working fluid of the gas turbine 2 after combustion is mainly composed of CO2 and N2, and the CO2 concentration of the surplus gas is as low as about 50%, requiring the CO2 separation and recovery device 9.

Further, since NOx is generated due to thermal combination, measures against NOx are required.

Furthermore, according to the Argonne method shown in Figure 4, pure 0□
Since the replenishment is performed on the suction side of the compressor 1, when extracting the blade cooling gas of the gas turbine 2 from the discharge port of the compressor 1,
0. Not subjected to combustion. Also extracted, this results in a power loss for the O1 production device 11.

Furthermore, since 02 enters the exhaust gas, the CO2 concentration of the surplus gas decreases accordingly.

The present invention was made to solve the problems of the conventional technology, and is designed to increase the recovery rate of CO2 gas, reduce the power loss of the 02 production equipment, and create a CO2 recovery power generation plant that does not generate harmful gases. The purpose is to provide

Means for Solving the Problems In order to solve the above problems, the present invention provides an o
A pushing compressor that compresses 2, and a pushing compressor that compresses 0.
2, a combustor that is supplied with fuel and burns it in pressurized gas; a gas turbine that is supplied with high-temperature gas from the combustor and rotates; and an exhaust heat recovery boiler that is supplied with exhaust gas from the gas turbine. , comprising a condenser that condenses exhaust gas from the exhaust heat recovery boiler, and a compressor to which a portion of the exhaust gas from the condenser is supplied, compresses the exhaust gas, and supplies it to the gas turbine. .

According to the above-mentioned means, the pure O2 produced by the O2 production equipment
is directly supplied to the combustor using a forced compressor.

Therefore, the gas sucked into the compressor is only CO2, and the gas extracted from the discharge port of the compressor and used for cooling the gas turbine blades is also only CO2, and no 02 is mixed into the gas turbine. Then, the rest goes into the combustor and becomes 0.
It is mixed with pure 02 sent from 2 manufacturing cargo and burned. Therefore, all of the pure 02 produced is provided for combustion.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to FIG.

In FIG. 1, the same elements as in FIGS. 2 to 4 are given the same reference numerals and redundant explanations are omitted, but in the present invention, 0! A compression compressor 12 is provided at the rear stage of the manufacturing unit 11, and O! compressed by this compression compressor 12! The combustor 3
We are trying to supply directly to

According to the above configuration, the CO7 sucked into the compressor 1 is compressed and a part of it passes through the turbine blade cooling gas extraction line 9 and enters the gas turbine 2, and the remaining CO2 is transferred to the combustor 3.
to go into. Further, the pure 02 manufactured by the 02 manufacturing apparatus 11 is compressed by the forcing compressor 12 and enters the combustor 3, where it is mixed with fuel and CO3 and combusted to become high-temperature gas (Cow). This high-temperature gas is sent to the gas turbine 2 and expanded to become a power source for the generator 4 and compressor 1.

The exhaust gas of the gas turbine 2 is heat-utilized for steam production in the exhaust heat recovery boiler 5, and then cooled in the exhaust gas condenser 8 to remove moisture and become circulating gas, which is then circulated again as the suction gas of the compressor 1. do. When circulating as circulating gas (Cot), surplus CO due to 0° replenishment! is recovered as surplus gas.

In addition, in the present invention, oil, methanol, natural gas,
Fuels made of compounds of hydrogen and carbon, such as LPG, and CO and H! A wide range of fuels can be used, including gases whose main components are (blast furnace gas, converter gas, by-product gas from petrochemical plants, etc.).

Effects of the Invention As described above, according to the present invention, (1) 02 is not mixed in the exhaust gas of the gas turbine;
Since the concentration of CO2 is high (approximately 94%), when recovering it as surplus gas, there is no need for a CO2 separation and recovery device, and the recovery rate is high: (2) Since 02 is not consumed other than combustion, ．． The power loss of the manufacturing equipment can be reduced; and (3) since the supplementary gas is pure 0□, there is no N2 component and no harmful gases such as NOx are generated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a CO2 recovery power generation plant showing one embodiment of the present invention, and FIGS. 2, 3, and 4 are block diagrams showing three different conventional examples. 1.Compressor, 2.Gas turbine, 3.Combustor, 4
... Generator, 5. Exhaust heat recovery boiler, 7. Extraction line, 8. Condenser, 10. Circulation system, 11. 0□ manufacturing equipment, 12. Compressor for forcing.

Claims (1)

[Claims] A forced compressor that compresses O_2 produced by the O_2 production equipment, a combustor that is supplied with O_2 and fuel from the forced compressor and burns it in pressurized gas, and a high-temperature gas from the combustor. A gas turbine that is supplied and rotates, an exhaust heat recovery boiler that is supplied with exhaust gas from the gas turbine, and a condenser that condenses the exhaust gas from the exhaust heat recovery boiler.
A CO_2 recovery power generation plant characterized by comprising a compressor to which a portion of the exhaust gas from the condenser is supplied, compresses the exhaust gas, and supplies the compressor to the gas turbine.