JPH11350972A - Gas turbine combined cycle power generation system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To produce syngas from fuel gas in order to achieve both the energy efficiency improvement of gas turbine combined cycle power generation and the improvement of power load following ability to enable power load leveling during the day and night. To provide a system that integrates chemical energy storage of electric power by liquid fuel production via the system and its hydrogen conversion combustion and power generation. SOLUTION: A synthesis gas is passed by passing a fuel gas containing methane through an oxygen ion / electron mixed conductive solid electrolyte membrane reactor and efficiently performing partial oxidation by utilizing the oxygen selective permeation performance of the solid electrolyte membrane. By manufacturing it and converting it into a liquid fuel with excellent storage properties and easy hydrogen release as a raw material, it stores chemical energy of electric power, improves the ability to follow the power load, and further reforms this liquid fuel by steam reforming. Integrated from synthesis gas production to methanol production and storage to hydrogen production by steam reforming to hydrogen fuel gas turbine combined cycle power generation designed to improve energy efficiency by introducing hydrogen-based gas into the power generation system Oxygen and liquid fuel co-production hydrogen conversion combustion gas turbine combined cycle power generation system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combined cycle power generation system which has been actively adopted as a technique for achieving high-efficiency power generation while suppressing the emission of carbon dioxide, which is regarded as a main working gas for global warming. In particular, the present invention relates to a high-efficiency power generation and energy saving technology characterized by reducing exergy loss during combustion by reforming fuel. On the other hand, the current power generation equipment has a capacity design that responds to the peak demand for electric power. Converting and storing the generated thermal energy into chemical energy, and at the peak of daytime demand, converting this chemical energy into electric power via thermal energy to equalize the power load during the day and night. It is also a power peak cut technology.

[0002]

2. Description of the Related Art While global environmental issues are becoming increasingly important, global warming due to carbon dioxide has been widely adopted, and controlling carbon dioxide emissions has been renewed as an urgent issue. In addition to the development of renewable energies such as solar cells and wind power generation, active development of energy-saving measures for existing industrial plants, development of technologies to improve the efficiency of power generation equipment, etc., to reduce carbon dioxide within and across industries Technology development is progressing. Among them, natural gas is attracting attention as a clean energy for electric power with a low carbon content, and a gas turbine combined cycle power generation system (GTCC) that uses natural gas as fuel to improve power generation efficiency by connecting to gas turbines and steam turbines Is being developed and commercialized. Further, technical developments aimed at improving the power generation efficiency have been carried out, but most of them are mostly controlled by a steam turbine power generation system (for example, JP-A-6-159091) and a steam-turbine cooling mechanism design (for example, JP-A-9-1991). -170407
JP-A-10-61457), gas turbine blades using superalloys, nozzle designs (for example, JP-A-6-10082 and JP-A-7-70679), low-boiling medium cycle power generation, It is limited to coupling with active gas medium cycle power generation (for example, JP-A-7-166815 and JP-A-9-14560), and there is no technology relating to power generation system design that takes fuel quality into consideration.

[0003] On the other hand, the general situation of power supply and demand in Japan can be summarized as the progress of information communication and the softening of the economy
The power disparity between day and night has widened, and at present the power supply operation rate in Japan has fallen to a low level of 55%, and further reduction is expected in the future. The power required for cooling in the daytime, especially in summer, is the main factor of the peak, and various technological developments are being carried out to level the power load by peak cut and establish a sound power supply and demand structure. Typical technology development items are flywheel power storage technology, high-performance battery power storage technology, ice heat storage technology, and gas cooling technology for nighttime power storage using rotational energy. Have been.

[0004] In the gas turbine combined cycle power generation, there have been sporadic developments of technologies for improving load following capability.
Switching between the combined power generation mode and the steam turbine single power generation mode (for example, JP-A-6-173615), deviation detection control between a target load and an actual load (for example, JP-A-5-5-2)
No. 72361, Japanese Unexamined Patent Publication No. 8-128304), and there is no technology relating to a load variation tracking function that can cope with a large load variation between day and night.

[0005] The development of technologies for improving the power generation efficiency and leveling the power load is a highly independent subject in the development of technologies of different quality, and it is quite difficult to achieve both. For example, the development of GTCC is intended to improve energy efficiency by collecting combustion energy in cascade using clean gas as a raw material. Even now, power generation efficiency has been improved by the development of high-efficiency gas turbines. However, from the viewpoint of power load leveling, a mechanism for leveling is not particularly built in.
There is a main focus of technology development on suppressing a decrease in load following performance due to an increase in thermal inertia.

[0006] On the other hand, a composite system with another plant has been proposed for the purpose of effective use of GTCC heat energy, although it is not intended for power load leveling. (For example, US Pat. No. 5,516,359), combination with a fuel cell (for example, JP-A-9-129255), and combination with LNG vaporization (for example, JP-A-9-14).
587), a combination of a cryogenic air separation plant and compressed air storage power generation (for example, Japanese Patent Application Laid-Open No. 9-13918), and the like.
It is difficult to provide the GTCC with power load following capability. For example, considering the technology combined with air separation, large-capacity oxygen and nitrogen production is performed by installing a cryogenic separation plant close to the location of a major user of these gases. Considering that air separation technology is power-consuming, it has already been incorporated as part of the effective use of inexpensive night-time power. Is considered to be ineffective.

[0007] The power load leveling technology is positioned as a technology applicable to substations, distribution stations, and the terminal receiving side after the power plant, and is being developed independently of the power generation equipment. At present, there is no direct relationship with the efficiency of the project.

[0008]

According to the present invention, the improvement of the power efficiency of the power generation equipment is reviewed from the viewpoint of fuel quality, a hydrogen source of the fuel is extracted as hydrogen gas, and the fuel is converted to a hydrogen-based fuel composition. An object is to construct a power generation system with less exergy loss generated in the irreversible process of combustion. Furthermore, for power load leveling, thermal energy is not converted into electric power at night but converted into chemical energy (chemical substance) with high storability, and this chemical substance is converted into hydrogen with less exergy loss at daytime. An object of the present invention is to provide a high-efficiency gas turbine combined cycle power generation system that follows a power load and performs high-efficiency power generation by using it as fuel. Hydrogen is a medium that combines high-efficiency power generation and power load leveling, and the core technology is to produce liquid fuel that easily generates hydrogen and has excellent storage properties.

[0009]

According to the present invention, methane, which is a main component of natural gas, is not only a clean energy source, but also a convenient hydrogen source that can be easily converted into synthesis gas. The focus was on the fact that it can be easily converted to liquid fuel, especially methanol. In addition, methanol is considered to be a liquid fuel for mobile vehicles in place of LNG (liquefied natural gas) and gasoline, and a polymer electrolyte fuel cell (PEFC), which has attracted attention as a power source for vehicles, uses methanol as a raw material. The high overall fuel efficiency of 60% (less than 30% for an internal combustion engine using methanol as fuel) using hydrogen obtained by the steam reforming as fuel is Be.
NZ, Toyota, etc. At present, a high power generation efficiency of nearly 50% is obtained even in a GTCC using natural gas as a fuel, and a further improvement in efficiency can be achieved by converting to a hydrogen-based fuel configuration. This is because the exergy loss in the irreversible process of combustion inherent to hydrogen is small. In other words, as compared with other fuels, the combustion reaction process in a combustion engine that can be realized at present progresses with a low bias from the reaction equilibrium, so that the energy loss in the irreversible process of combustion can be reduced. It becomes possible.

Furthermore, a process for producing hydrogen from natural gas represented by steam reforming of natural gas is based on an endothermic chemical reaction that proceeds at a lower temperature than the combustion reaction, and converts natural gas into hydrogen. Combustion is considered to be a type of heat pump that pumps heat at low temperatures (endothermic reaction during reforming) and releases heat at high temperatures (exothermic reaction during combustion). It is economically advantageous.

Although the production of hydrogen by steam reforming of natural gas and its use as a fuel are originally the most efficient systems, hydrogen has difficulties in storage, and although the development of hydrogen storage alloys is in progress, the industrialization Is considered to take time. Furthermore, 700 ° C. is required for hydrogen production by steam reforming.
The above temperature is required, and the temperature of the steam extracted from the steam turbine is insufficient, and a large amount of steam is required to supply more heat or shift the equilibrium of the reaction to the hydrogen generation system. Inevitably, the size of the methane becomes large and unreformed methane remains. On the other hand, methanol as a hydrogen source is liquid and has excellent storage properties, and is easily steam reformed at a low temperature of 300 ° C or lower to release hydrogen, so that GTCC exhaust steam can be used and energy can be cascaded. This is also advantageous from the viewpoint of doing so. Taking these factors into account, the intensive study on various hydrogen conversion and storage systems based on GTCC resulted in the conversion of methanol, which is a good hydrogen generation medium (steam reforming at low temperature and easily generates hydrogen) into methanol. The inventors have found that the system used as an energy storage source is optimal, and have completed the present invention.

There are various methods for synthesizing a liquid fuel using natural gas as a raw material, and an indirect method via synthesis gas is mainly used. At the basic research level, under a mixture of methane and oxygen,
There is also a method of synthesizing methanol from methane in a single step by plasma excitation at room temperature and pressure, but this is not at a level where industrialization can be foreseen. When based on the indirect method, the current mainstream of synthesis gas production is the steam reforming method, but the ratio of generated hydrogen to carbon monoxide is hydrogen / carbon monoxide = 3/1, and liquid fuel is synthesized. In the case of FT (Fischer-Tropsch) synthesis, which is a typical liquid fuel production process, a widely distributed hydrocarbon is produced while simultaneously producing water, which is not efficient. On the other hand, the synthesis gas composition ratio, hydrogen / carbon monoxide = 2/1, which is said to be suitable for liquid fuel synthesis, can be easily obtained by partial oxidation of methane, but requires a cryogenic separation method oxygen plant for oxygen supply. Which is disadvantageous in terms of energy. When methanol is considered as the liquid fuel, the synthesis gas composition ratio, hydrogen / carbon monoxide = 2/1, is stoichiometrically equal to the methanol composition, and the partial oxidation method is an ideal synthesis gas production method.

Among the technologies related to the natural gas partial oxidation method, attention is paid to a membrane reactor using a mixed conductive solid electrolyte of oxygen ions and electrons, and the incorporation into a system as a compact and highly efficient reaction process is studied. did. In addition, it is suggested that the technology can significantly reduce the cost of syngas production (for example, “Ceramic membrane reactor fo
r converting methane to syngas ", Catalysis Today,
36, 265-272 (1997)).

FIG. 1 is a schematic diagram of a membrane type methane partial oxidation apparatus using an oxygen transporting solid electrolyte. In this reactor, a catalyst for partial oxidation of methane is applied to the permeation side of the solid electrolyte membrane to take advantage of the high activity of oxygen permeating in an ionic state at a high temperature (800 to 1000 ° C.) to achieve a high reaction yield. Can be realized.

According to the present invention, under these general views, the power generation efficiency is improved, and at the same time, it has the ability to follow the power load fluctuation.
As a high-efficiency combined power generation system that reduces carbon dioxide emissions, using methane-containing gas as fuel, in parallel with power generation, syngas production by partial oxidation, synthesis of methanol from synthesis gas, and hydrogen production by steam reforming of methanol ,
It proposes an integrated system combined with a series of chemical reaction processes of using hydrogen as fuel. Methanol is
Not only for use as fuel for power generation, but also promising as fuel for future fuel cell vehicles, the system of the present invention,
It is assumed that it greatly contributes to the reduction of carbon dioxide emission from the dispersed carbon dioxide gas generation source.

The gist of the present invention is as follows. (1) In a gas turbine combined cycle power generation system including a high-pressure combustor, a gas turbine system using the combustion gas as a working fluid, and a steam turbine system using the exhaust heat of the gas turbine as a heat source, the raw material gas is partially oxidized. Of a hydrogen-based gas obtained via a membrane reactor for converting to a synthesis gas, a reactor for producing a liquid fuel from the synthesis gas, and a reforming reactor for reforming the liquid fuel with steam Or a gas turbine combined cycle power generation system, wherein the entire amount is supplied to the high-pressure combustor. (2) The membrane reactor according to (1), wherein the membrane reactor for partially oxidizing the raw material gas and converting it into synthesis gas is a membrane reactor having an oxygen ion / electron mixed conductive solid electrolyte membrane and a methane partial oxidation catalyst layer. Gas turbine combined cycle power generation system. (3) The gas turbine combined cycle power generation system according to (2), wherein the membrane reactor is also used as an oxygen enrichment device. (4) The raw material gas is natural gas, coal pyrolysis gas, and / or
Or the gas turbine combined cycle power generation system according to any one of (1) to (3), which is coke oven gas (COG). (5) The gas turbine combined cycle power generation system according to any one of (1) to (4), wherein the liquid fuel is methanol. (6) In the gas turbine combined cycle power generation system according to any one of (1) to (5), the raw material gas is partially oxidized and converted into synthesis gas in the membrane reactor during the night when the power load is low. A method for operating a gas turbine combined cycle power generation system, wherein the reactor is used as an oxygen enrichment device during the daytime when the power load is high.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. FIG. 2 is an example of a gas turbine combined cycle power generation system using natural gas as fuel. This system incorporates a mixed-conducting solid electrolyte membrane reactor with both oxygen ion and electron permeability, which separates and supplies oxygen from the air during the day when electricity prices are high, and during the night, In addition to separating oxygen from air, natural gas is fed to the low pressure side of the membrane and used as a synthesis gas production device by partial oxidation. In consideration of this difference in the purpose of use during the day and night, by applying a methane partial oxidation catalyst (a mesh-like porous Rh catalyst, etc.) on the low-pressure side of the mixed conductive solid electrolyte membrane, the power load at night or the like can be reduced. In order to utilize as a synthesis gas production device, natural gas is flowed to the low pressure side (stream 8), and high yield is obtained by synergistic effect with the reaction activity of the catalyst layer formed on the permeation side in addition to the permeation of oxygen in the ion state. Partial oxidation of natural gas proceeds. On the other hand, during the daytime when the power load and price are high, an oxygen suction blower is connected to the permeate side of the membrane to recover the permeated oxygen in order to utilize it as an oxygen production device (there is no stream 8; Connected to the system). Since this solid electrolyte membrane reactor operates effectively at a high temperature of 800 ° C. or higher, fuel gas and air are burned by a high-pressure (about 16 atm) combustion burner, and a part of the generated combustion exhaust gas is separated from another series. The supplied air is mixed, adjusted to a predetermined temperature, and introduced into the solid electrolyte membrane reactor (stream 2).

When producing oxygen, the natural gas combustion gas introduced into the solid electrolyte membrane reactor passes through the membrane to the low pressure side through the membrane, and is recovered and used as high-purity oxygen by a suction blower. On the other hand, the nitrogen-rich exhaust gas through which oxygen has permeated (stream 3) is introduced into a combustion burner and mixed with the combustion exhaust gas from a viewpoint of utilizing sensible heat, and is mixed with a high temperature (about 1400 ° C.) and high pressure (about 16 atm). ) It becomes a gas turbine drive source as exhaust gas (stream 4). The heat energy is converted into electric energy through the gas turbine, and the exhaust gas (stream 5) having a reduced energy level is introduced into a steam recovery device, and the heat energy is used for generating steam and then exhausted. In the steam turbine, the heat energy of the generated steam is converted into electric energy, and the steam having the reduced energy level is exhausted as medium / low temperature steam (stream 7), and after condensate, is circulated in the system as a steam generation source. Is done.

The above system is a co-produced gas turbine combined cycle power generation system.
It can be operated by adjusting the membrane area or the flow rate of the heated air according to the oxygen demand. This co-producing oxygen type GTCC is considered to be an efficient system for supplying high-purity oxygen while recovering power. A cryogenic oxygen production plant that creates a low-temperature liquefied state by power consumption of a refrigerator and obtains high-purity oxygen by distillation. On the contrary, it is characterized in that electric power is recovered using high-temperature exhaust heat while extracting high-purity oxygen using a selective transport medium for oxygen in a high-temperature state. The high-purity oxygen obtained has a high temperature, and the sensible heat can be used to improve the efficiency of the oxygen utilization reaction. Examples of the case used for combustion include oxygen injection for a refuse melting furnace, oxygen-enriched air for pulverized coal injection (PCI) into an ironmaking blast furnace, and oxygen injection for coal gasification. In the future, it is assumed that it can be used as an oxygen source for direct reduction steelmaking. In addition, this sensible heat can be used to apply to chemical reaction processes involving oxygen other than combustion. As a typical example, partial oxidation of methane, which is a main component of natural gas that is also a fuel gas for power generation, is possible. We focused on the reaction.

The operation mode at night will be described with reference to FIG.
In the nighttime, the demand for electricity decreases and the rates become cheaper, so that the operating rate of the co-produced GTCC is inevitably reduced, and even if the operation is switched to the operation based on oxygen production, the electricity as a by-product will be cheaper. Therefore, the economic effect is poor. In the present invention, the solid electrolyte membrane is utilized as a natural gas partial oxidation reactor at night. Natural gas is caused to flow to the low pressure side of the solid electrolyte membrane reactor (stream 8), and synthesis gas is generated by the following reaction between methane, which is a main component in natural gas, and permeated oxygen. CH ₄ + 1 / 2O ₂ = CO + 2H ₂ This synthesis gas generation reaction proceeds with a selectivity and a yield close to 100% by the Rh-based catalyst. The generated synthesis gas is pressurized to 80 atm after heat exchange and introduced into a methanol reaction tower (stream 9). In the methanol reaction tower, methanol is synthesized by the following reaction formula. CO + 2H ₂ ＣＨCH ₃ OH

At this time, the CO and H ₂ ratio in the synthesis gas is as follows:
It is the same as the stoichiometric ratio of methanol, and can be directly introduced into a methanol reactor without the need for adjusting the ratio. The methanol synthesis technique is not particularly limited, but is a general-purpose technique, and usually employs a medium-low pressure method (pressure: about 80 kg / cm ² , temperature: 200 to 300 ° C.). The synthesized methanol is subjected to post-treatment such as purification, and then sent to a storage tank and stored (stream 10). Further, this methanol is mixed with steam turbine exhaust steam (streams 11 and 12), introduced into a steam reformer, and converted into hydrogen by the following reaction. CH ₃ OH + H ₂ O = 3H ₂ + CO ₂

This hydrogen-rich gas, after removing water vapor,
The fuel is introduced into the burner as a fuel (stream 13), and the combustion gas is used for raising the sensible heat of the air supplied to the solid electrolyte membrane reactor and driving the gas turbine.
In addition, excess methanol is stored, converted to hydrogen via steam reforming during the daytime when the power load is high, and the system is operated using this as fuel, so that all-hydrogen fuel can be used. In this way, at night, heat energy is stored as chemical energy as a process operation mainly composed of methanol, and it has the ability to follow power load fluctuations.At the same time, the fuel system is switched to a hydrogen fuel system with high exergy efficiency throughout the day and night. It is the intention of the present invention to provide a permanent measure against global warming by converting and improving combustion efficiency.

The methanol produced and stored at night can be sold as a chemical, a hydrogen source, or a fuel depending on the application. The combined process of the present invention is a system that combines electric power and chemistry through methanol. You might also say that.
Further, the gas used in the present invention is not limited to natural gas, but can be applied to all gases including methane, and is a hydrogen-rich coke oven gas containing about 30% methane (CO gas).
G) It is applicable to a coal pyrolysis gas containing about 12% of methane. In the present invention, these gases containing methane can be used alone or in a suitable mixture.

[0024]

The present invention will be described below with reference to examples. (Example) Preparation method of oxygen ion / electron mixed conductive solid electrolyte membrane (1) Preparation of porous ceramics Prepared using yttria-stabilized zirconia (YSZ).
YSZ powder (manufactured by Nissan Chemical Industries, NZP-C8Y) is pulverized by a ball mill, pressurized, pre-sintered at 1100 ° C., and then 1300 ° C.
Sintered. Scanning electron microscopy observation confirmed that 250 nm diameter holes were monodispersed. The measured porosity using a mercury porosimeter was 28%.

(2) Surface treatment of porous ceramic Sr _{2 on} both front and back surfaces of the YSZ porous membrane prepared in (1)
First, a mixed solution of YSZ powder sol and YSZ polymer sol was prepared as a wet surface treatment agent in order to form a Fe ₃ O _6.25- based thin film by treating the surface layer of the porous film to be nanoporous. . As a YSZ powder sol, yttrium nitrate hexahydrate is added to a 0.05 mol / l aqueous zirconia powder sol, and (Y ₂ O ₃ )
_0.08 (ZrO ₂ ) _0.92 . Also, Y
The SZ polymer sol is prepared by mixing tetra-n-butoxyzirconium as a precursor, triethanolamine as a chelating agent and water in a molar ratio of 1: 2: 2, and hydrolyzing and condensing with isopropanol as a diluent. The reaction was allowed to proceed completely to give a stock solution. At this time, the zirconium concentration is
It was prepared to be 0.05 mol / l. Furthermore, in this stock solution,
Similarly to the preparation of the YSZ powder sol, yttrium nitrate hexahydrate was added so that the composition at the time of firing was (Y ₂ O ₃ ) _0.08 (ZrO ₂ ) _0.92 to prepare a YSZ polymer sol preparation. The above prepared YSZ powder sol preparation liquid and YSZ polymer sol preparation liquid are mixed so as to have a volume ratio of 1: 1.
A thin film was formed on the surface layer of the YSZ porous film prepared in (1) by dip coating. At this time, 80 ° C, 3
After drying for 0 minutes, a dried film was obtained under a heat treatment condition of 600 ° C. for 1 hour, and coating and heat treatment were repeated so that the dried film thickness became 1 μm. In scanning electron microscope observation,
It was confirmed that pores having a diameter of 20 nm were monodispersed.
This surface treatment step is indispensable for the next thin film manufacturing step.
Unless the pore diameter is adjusted to 50 nm or less, stable formation of the solid electrolyte thin film was difficult.

(3) Preparation of oxygen / electron mixed conductive solid electrolyte thin film A Sr ₂ Fe ₃ O _6.25 thin film is formed on one surface of the surface nanoporous ceramic prepared in (2) by MOCVD (organic metal chemical vapor deposition). did. As a raw material, di (di-pivaloymethane) strontium (Sr ((CH ₃ ) ₃ CCOC)
HCOC (CH ₃ ) ₃ ) ₂ ) and tri (di-pivaloymethane) iron (Fe ((CH ₃ ) ₃ CCOCHCOC)
Using (CH ₃ ) ₃ ) ₃ ), a vapor deposition treatment is performed for 30 minutes at a substrate temperature of about 750 ° C. and a pressure of about 0.01 atm under adjoining oxygen-containing argon gas. A thin film was formed.

(4) Preparation of Catalyst A Rh thin film catalyst layer was formed on the back surface of the porous ceramics prepared in the above (3) by MOCVD (organic metal chemical vapor deposition). As a raw material, tri (acetylacetonate) rhodium (Rh (CH ₃ COCHCOCH ₃ ) ₃ )
Then, a vapor deposition treatment was performed for 10 minutes under the condition of a substrate temperature of about 750 ° C. and a pressure of about 0.01 atm under an oxygen-containing argon gas, thereby forming a thin film having a thickness of about 0.5 μm.
Furthermore, the temperature was raised to about 800 ° C., and a partial oxidation treatment was performed in an air atmosphere for 5 hours to improve the catalytic activity.

(5) Oxygen Permeability Coefficient Measurement, Natural Gas Partial Oxidation Reaction Measurement
The oxygen-containing combustion exhaust gas was supplied to the electrolyte membrane prepared in the above (1) to (4) under the conditions of 850 ° C. and 16 atm, and an oxygen permeation experiment was performed. Was obtained on the permeation side adjusted to atmospheric pressure, and a value of 0.6 cm ³ (STP) / sec · cm ² was obtained as the oxygen permeation coefficient. The oxygen recovery was 15%. Next, a natural gas was introduced into the permeation side of the membrane, and a synthetic gas production experiment was performed by a partial oxidation reaction between the permeated oxygen and the natural gas. A reaction rate of 99% or more with respect to the permeated oxygen and a value of 98% were obtained as the selectivity of the partial oxidation reaction. From the above results, it is clear that the oxygen / electron mixed conductive solid electrolyte membrane has high oxygen permeability, and that the oxygen / electron mixed conductive solid electrolyte membrane coated with the catalyst has high natural gas partial oxidation ability. It became.

Table 1 shows the process parameters of the night operation when the process shown in FIG. 2 was constructed based on the above basic data. The gas component concentration shown in the table in% by volume, the flow rate is indicated by 1000 Nm ³ / Hr units (KNm ³ / Hr).

[0030]

[Table 1]

This embodiment is based on the system operation under the following conditions. Burner: Air-fuel ratio 1.2 Gas turbine + steam turbine: Power conversion rate 48% (methane fuel), 53% (hydrogen fuel) Gas turbine inlet temperature 1350 ° C Gas turbine outlet temperature 660 ° C Gas turbine inlet pressure 16 atm Gas turbine outlet pressure 1 atm Steam turbine inlet temperature 400 ° C Steam turbine outlet temperature 280 ° C Steam turbine inlet pressure 50 atm Steam turbine outlet pressure 1 atm Solid electrolyte membrane reactor: Gas inlet pressure 16 atm Transmission side Pressure 1 atm Oxygen production capacity 10,000 Nm ³ / Hr Oxygen purity> 99.9% Membrane area 500 m ² Partial oxidation reaction: Natural gas supply 20,000 Nm ³ / Hr Natural gas supply pressure 1 atm Natural gas conversion 99% Oxidation reaction selectivity 98% Reaction temperature 850 ° C Methanol synthesis reaction: Overall reaction yield 95% Reaction temperature 300 ° C Reaction pressure Power 80 atm Methanol steam reforming reaction: Methanol conversion 95% Steam / methanol ratio 2.0 Reaction temperature 250 ° C

This system has a solid electrolyte membrane with an oxygen production capacity of 10,000 Nm ³ / Hr, a synthesis gas production by partial oxidation of natural gas, a methanol synthesis, a hydrogen production by methanol steam reforming, and a gas turbine using hydrogen as fuel. The combined cycle power generation (a part of the high-temperature combustion gas is introduced into the solid electrolyte membrane, and after recovering oxygen, the remaining gas is introduced into the gas turbine) is integrated. At night when power demand falls, excess power is stored as methanol, and when daytime power demand increases, this methanol is converted to hydrogen by steam reforming and converted to power by burning it as fuel. .

The oxygen production capacity of the solid electrolyte membrane is 10,
On the basis of 000 Nm ³ / Hr, the partial oxidation ability of natural gas is twice as large as 20,000 Nm ³ / H from the stoichiometric ratio.
Hr. Methanol is produced using synthesis gas from partial oxidation as a raw material, and its production capacity is 18,434 Nm.
³ / Hr, 26.3 tons / Hr (more than 630 tons / day) in weight conversion. Since the maximum production capacity of the current methanol plant is 1000 tons / day / unit, and the system is based on the assumption that methanol is produced at night, the scale of one plant is appropriate. This methanol is mixed with the exhaust steam of 280 ° C. from the steam turbine, and then mixed with 250 ° C.
To produce 52,537 Nm ³ / Hr of hydrogen, which is used as a fuel for power generation. Since methanol is not produced during the daytime when the power load is high, and methanol accumulated at night is steam reformed and used as a power generation gas, no raw material gas is supplied to the low pressure side of the membrane reactor (FIG. 2). No stream 8 in the inside), functioning as a device for separating oxygen from air.

[0034]

The power generation scale of the system of the present invention is about 10
It will be 10,000 kW, and the power generation efficiency will be about 50%. That is,
Compared to the case where natural gas is used as fuel, it is possible to reduce fuel consumption by about 4% and reduce carbon dioxide emissions. This is because the fuel conversion from natural gas to hydrogen reduces energy loss during combustion and improves power generation efficiency.

Further, from the viewpoint of the ability to follow the power load, the system of the present invention makes use of the power demand / price difference between day and night, and performs high-efficiency power generation by converting hydrogen produced at night during the hydrogen conversion combustion of methanol. While producing oxygen and supplying it as inexpensive oxygen to the required places, at night, methanol is produced via synthesis gas by using the solid electrolyte membrane for partial oxidation of methane, and furthermore, methanol conversion and combustion In this way, the remaining methanol is stored and supplied as fuel during the day, and the power load can be leveled during the day and night, while generating high-efficiency power and supplying the remaining methanol as fuel during the day. Furthermore, the surplus portion of the oxygen produced during the daytime and the methanol produced at nighttime that is not used for internal power generation can be recorded as revenue for external sales, contributing to the improvement of plant economics. As described above, the system of the present invention can freely operate the capacity of the component plant in consideration of the supply and demand balance of the electric power, oxygen, and methanol, and also enables the optimal system design according to the location conditions.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a system including oxygen permeation in an oxygen ion / electron mixed conductive solid electrolyte membrane, synthesis gas production by partial oxidation of natural gas using the same, and liquid fuel production.

Fig. 2 A simple combined cycle system from natural gas to synthetic gas production incorporating an oxygen ion / electron mixed conductive solid electrolyte membrane reactor, methanol synthesis, and hydrogen conversion and combustion power generation by methanol steam reforming. It is a figure showing a flow. It should be noted that the circled numbers on the arrows indicating the flows in the figure correspond to the stream numbers and are referred to in the text and Table 1 (however, the circles are omitted in the text).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Kubo 3-35-1, Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Nippon Steel Corporation Technology Development Division (72) Inventor Hideki Kurimura 1 Hatagaya, Shibuya-ku, Tokyo Teikoku Oil Co., Ltd. (72) Inventor Shoichi Kaganoi 1-31-10 Hatagaya, Shibuya-ku, Tokyo Inside Teikoku Oil Co., Ltd.

Claims (6)

[Claims] 1. A gas turbine combined cycle power generation system comprising a high-pressure combustor, a gas turbine system using the combustion gas as a working fluid, and a steam turbine system using a waste heat of the gas turbine as a heat source, wherein a raw material gas is partially used. Hydrogen-based gas obtained through a membrane reactor that oxidizes and converts it to synthesis gas, a reactor that produces liquid fuel from synthesis gas, and a reforming reactor that reforms this liquid fuel with steam A gas turbine combined cycle power generation system, wherein part or all of the gas is supplied to the high-pressure combustor. 2. A membrane reactor for partially oxidizing a raw material gas to convert it into a synthesis gas is a membrane reactor having an oxygen ion / electron mixed conductive solid electrolyte membrane and a methane partial oxidation catalyst layer. A gas turbine combined cycle power generation system according to claim 1. 3. The gas turbine combined cycle power generation system according to claim 2, wherein the membrane reactor is also used as an oxygen enrichment device. 4. The gas turbine combined cycle power generation system according to claim 1, wherein the raw material gas is natural gas, coal pyrolysis gas, and / or coke oven gas (COG). 5. The liquid fuel according to claim 1, wherein the liquid fuel is methanol.
5. The gas turbine combined cycle power generation system according to any one of 4. 6. The gas turbine combined cycle power generation system according to claim 1, wherein the raw material gas is partially oxidized and converted into synthesis gas in the membrane reactor at night when the power load is low. A method for operating a gas turbine combined cycle power generation system, wherein the reactor is used as an oxygen enrichment device during the daytime when the power load is high.