JPH11294259A - Cogeneration power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the discharge of carbon dioxide with high efficiency and at a low cost by providing a piping system for feeding hot water and the hot carbon dioxide discharged from a material capable of absorbing and discharging carbon dioxide to the outside of a plant. SOLUTION: This cogeneration power plant is provided with a reformer 1 and a power generating device 2 capable of providing electric power and hot water by the oxidation reaction of the reformed fuel. A carbon dioxide separating device 3 recovering and discharging the carbon dioxide generated in the process of oxidation reaction is provided between the reformer 1 and the power generating device 2. A power feed line 4 and a hot water feed pipe 5 are installed from the power generating device 2 toward the outside of the plant, and a carbon dioxide feed pipe 6 is installed from the carbon dioxide separating device 3 toward the outside of the plant. Carbon dioxide is efficiently recovered during the power generation process, the carbon dioxide heated at the time of recovery is discharged, and it is fed to customers together with hot water. The discharge of carbon dioxide can be suppressed with high efficiency and at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a co-joining power generation plant utilizing a fuel containing hydrocarbon as a main component, and more particularly to a co-joining power plant capable of efficiently supplying carbon dioxide together with hot water. Related to power plants.

[0002]

2. Description of the Related Art A co-joining power plant is
A plant that converts fuels containing hydrocarbons as the main component, such as gas turbines and fuel cells, into electricity and hot water through an oxidation reaction, and supplies this to multiple consumers, and has been put into practical use as a regional system with high fuel efficiency. In the future, they are attracting great expectations.

[0003]

However, in the above-mentioned co-junction power generation plant, carbon dioxide accompanying the oxidation reaction of a gas turbine or a fuel cell is regarded as a main cause of global warming and emission control is required. Therefore, it is necessary to not only improve fuel use efficiency, but also to actively collect and use carbon dioxide gas.

According to the present invention, carbon dioxide gas accompanying the oxidation reaction of a gas turbine or a fuel cell is efficiently recovered during a power generation process. To achieve high-efficiency, low-cost control of carbon dioxide emissions,
Another object of the present invention is to provide a cogeneration power plant capable of supplying hot water with a large amount of heat energy to consumers.

[0005]

A cogeneration power plant according to the present invention comprises a first device for generating electric power and hot water by an oxidation reaction of a hydrocarbon-based fuel, and an oxidation reaction of the fuel by the first device. A second device containing a substance capable of physically or chemically absorbing carbon dioxide generated in the process and recovering the heated carbon dioxide gas and releasing the carbon dioxide gas; And a piping system for supplying the hot carbon dioxide gas released from the substance to the outside of the plant along with the hot carbon dioxide gas.

[0006] In the power plant according to the present invention, the substance contained in the second device reacts with carbon dioxide to recover as lithium carbonate, and releases carbon dioxide to form before the reaction of carbon dioxide. It is preferable that the carbon dioxide absorbent has a returning property.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a cogeneration power plant according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a first power generator including a reformer and a power generator including a gas turbine (or a power generator of a phosphoric acid type fuel cell).
It is a cogeneration power plant equipped with the equipment. This power plant includes a reformer 1, a power generator 2 for obtaining electric power and hot water by an oxidation reaction of a reformed fuel,
A second device interposed between the reformer 2 and the power generator 2 for recovering and releasing carbon dioxide gas generated in the course of the oxidation reaction.
The basic configuration is a carbon dioxide separation device 3 which is a device. The power generation device 2 including the gas turbine includes a combined cycle including a combustor, a gas turbine, and a waste heat recovery boiler. A power supply line 4 from the power generator 2,
A hot water supply pipe 5 is laid to the outside of the plant, and a carbon dioxide gas supply pipe 6 from the carbon dioxide separation device 3 is laid to the outside of the plant.

FIG. 2 shows a cogeneration power plant equipped with a first device comprising a reformer and a molten carbonate fuel cell as a power generator. This power plant
Connected to a reformer 1, a power generator 2 composed of a fuel cell that obtains electric power and hot water by reforming hydrogen or carbon monoxide by a fuel oxidation reaction, and an anode gas recovery system of the power generator 2 composed of the fuel cell And a second device for recovering and releasing carbon dioxide gas generated in the course of the oxidation reaction (carbon dioxide gas discharged from the fuel electrode outlet side of the power generator 2 comprising the molten carbonate fuel cell). The separation device 3 is used as a basic configuration. A power supply line 4 from the power generator 2,
A hot water supply pipe 5 is laid to the outside of the plant, and a carbon dioxide gas supply pipe 6 from the carbon dioxide separation device 3 is laid to the outside of the plant. The fuel component (hydrogen, carbon monoxide) after the carbon dioxide gas is collected and separated by the carbon dioxide gas separator 3 can be used as a fuel gas (anode gas) of the molten carbonate fuel cell. .

[0009] The outside of the plant to which the carbon dioxide gas is supplied is, for example, an agricultural producer who cultivates agricultural crops by releasing the carbon dioxide gas into a space having a translucent canopy, a synthesis of styrene and urea using carbon dioxide as a raw material. And carbon dioxide consumers such as entrepreneurs of the chemical industry. All consumers need not only carbon dioxide but also heat to achieve their goals.

The reformer 1 can be any type of reformer that converts a hydrocarbon-based fuel such as methane, petroleum, or coal into a gas containing hydrogen, carbon monoxide and carbon dioxide by catalytically converting the hydrocarbon-based fuel. It may be in a form. Further, depending on the necessity of carbon dioxide gas, a converter for further converting carbon monoxide generated by the catalytic action to hydrogen may be provided.

The carbon dioxide separator 3 contains a substance capable of physically or chemically absorbing carbon dioxide to recover heated carbon dioxide and releasing the carbon dioxide.

As a substance capable of physically absorbing carbon dioxide gas, recovering heated carbon dioxide gas and releasing the carbon dioxide gas, for example, zeolite or the like can be used.

The substance capable of chemically absorbing carbon dioxide to recover heated carbon dioxide and releasing the carbon dioxide is, for example, reacted with carbon dioxide and recovered as lithium carbonate, and A carbon dioxide absorbing material or the like having a property of releasing carbon dioxide and returning to the state before the reaction of carbon dioxide can be used.

In particular, the latter carbon dioxide absorbent is suitable. Examples of the absorbent include a lithium compound mainly composed of an oxide selected from aluminum, titanium, iron, nickel and zirconium. These absorbents absorb and collect carbon dioxide according to the following equations (1) to (5), and release carbon dioxide by the reverse reaction.

2LiAlO ₃ (s) + CO ₂ (g) → Al ₂ O ₃ (s) + Li ₂ CO ₃ (l) (1) Li ₂ TiO ₃ (s) + CO ₂ (g) → TiO ₂ (s) + Li ₂ CO ₃ (l) ... (2) 2LiFeO ₂ (s) + CO ₂ (g) → Fe ₂ O ₃ (s) + Li ₂ CO ₃ (l) ... (3) Li ₂ NiO ₂ s) + CO ₂ (g ) → NiO (s) + Li ₂ CO ₃ (l) (4) Li ₂ ZrO ₃ (s) + CO ₂ (g) → ZrO ₂ (s) + Li ₂ CO ₃ (l) (5) The reaction of the formula (1) tends to occur particularly at a temperature of 350 ° C. or lower.

The reaction of the formula (2) is particularly likely to occur at a temperature of 310 ° C. or lower. The reaction of the formula (3) is particularly likely to occur at a temperature of 400 ° C. or less. The reaction of the formula (4) is particularly likely to occur at a temperature of 450 ° C. or lower.

The reaction of the formula (5) is particularly likely to occur at a temperature of 550 ° C. or less. Each of the carbon dioxide absorbents absorbs and collects carbon dioxide by contacting with a gas containing carbon dioxide at the temperature or lower, and can release carbon dioxide by heating at or above these temperatures. That is, the released carbon dioxide gas is heated to a predetermined temperature.

The power supply line 4, the hot water supply pipe 5, and the carbon dioxide gas supply pipe 6 may have any form as long as they can supply electric power, hot water, and heated carbon dioxide gas to the outside of the plant. However, it is necessary that the carbon dioxide gas supply pipe 6 and the hot water supply pipe 5 be a piping system for supplying the heated carbon dioxide gas and the hot water to the outside of the plant together.

Specifically, as shown in FIG. 3, the hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 are laid to the outside of the plant in direct contact with each other. As shown in FIG. 4, the hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 are brought into direct contact with each other. In these piping systems, the hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 may be located as close to each other as necessary so that heat can be transferred between the two pipes. However, it is preferable to make direct contact as shown in FIGS. 3 and 4 from the viewpoint of thermal efficiency.

Further, as shown in FIG.
And carbon dioxide 10 are supplied, and the pipe 8 is laid toward the outside of the plant in a form covered with a heat insulating material 7.
As shown in FIG. 6, a double pipe structure including an inner pipe 11 and an outer pipe 12 is provided, and hot water and carbon dioxide gas are supplied to one of the inner pipe 11 and the outer pipe 12, and the periphery of the double pipe is insulated. It is laid to the outside of the plant in a form covered with the material 7.

By using the above-described embodiment, particularly, the embodiment shown in FIGS. 4 to 6, it is possible to effectively suppress the cooling of the hot water. The cogeneration power plant according to the present invention described above includes a first device that generates electric power and hot water by an oxidation reaction of a hydrocarbon-based fuel, and a carbon dioxide gas generated in a process of oxidizing the fuel by the first device. Recovers the heated carbon dioxide gas physically or chemically, and stores a second device containing a substance capable of releasing the carbon dioxide gas, and the hot water and the heated carbon dioxide gas. And a piping system for supplying it to the outside of the plant.

According to such a configuration, the cooling of the hot water in the supply process can be suppressed by the heated carbon dioxide gas by laying the piping system for accommodating the hot water and the heated carbon dioxide gas. In addition to carbon dioxide gas, hot water with high thermal energy can be supplied to the outside of the plant. Further, it is possible to efficiently collect the carbon dioxide gas discharged from the first device that generates the electric power and the hot water by the oxidation reaction of the hydrocarbon-based fuel, thereby suppressing the carbon dioxide gas discharge.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. (Example 1) The power plant shown in FIG. 1 described above was assembled by combined cycle power generation using LNG as fuel. In the reformer 1, methane reforming with steam and conversion of carbon monoxide are performed to obtain 79% of H ₂ , 2% of CO, 18% of CO ₂ ,
1% of CH ₄ (volume ratio, dry base) was generated, and these gases were supplied to a carbon dioxide gas separator 3 filled with 4 tons of lithium zirconate having an average particle diameter of 1 μm to separate and collect carbon dioxide gas. The reformed gas from which the carbon dioxide gas was separated was supplied to the power generator 2 of the combined cycle to generate power.

The carbon dioxide gas collected by the carbon dioxide separation device 3 is released to produce hot carbon dioxide gas of 100 ° C., and at the time of power generation in the power generation device 2, hot water of 80 ° C. is generated by utilizing the heat of the steam turbine condenser. The hot water and hot carbon dioxide gas are supplied to the hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 shown in FIG.
Were brought into contact with each other and supplied to the outside of the plant by a piping system in which the periphery thereof was covered with a heat insulating material 7.

(Example 2) The above-described power plant shown in Fig. 1 was assembled using a phosphoric acid fuel cell using LNG as fuel. In the reformer 1, methane reforming with steam and conversion of carbon monoxide are performed to obtain 79% of H ₂ , 0% of CO, and 20% of CO _2.
%, CH ₄ 1% (volume ratio, dry base)
These gases were supplied to a carbon dioxide separator 3 filled with 2 tons of lithium zirconate having an average particle size of 1 μm to separate and collect carbon dioxide. The reformed gas from which the carbon dioxide gas was separated was supplied to the power generator 2 composed of a phosphoric acid type fuel cell to generate power.

The carbon dioxide gas recovered by the carbon dioxide separation device 3 is released to produce hot carbon dioxide gas of 100 ° C., and the waste heat of the battery body in the power generation device 2 is used to produce hot water of 80 ° C. The hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 shown in FIG. 4 described above were brought into contact with each other, and supplied to the customer through a piping system in which the periphery thereof was covered with a heat insulating material 7.

Example 3 The above-described power plant shown in FIG. 2 was assembled using a molten carbonate fuel cell using LNG as fuel. In the reformer 1, methane reforming with steam and conversion of carbon monoxide are performed to obtain 79% of H ₂ , 0% of CO, and CO _2.
20% and 1% of CH ₄ (volume ratio, dry base) were produced and introduced into the fuel electrode (anode) side of the power generator 2 composed of a molten carbonate type fuel cell to generate power. The gas discharged from the fuel electrode outlet side of the power generator 2 comprising the molten carbonate fuel cell is supplied to a carbon dioxide separator 3 filled with 2 tons of lithium zirconate having an average particle diameter of 1 μm to separate carbon dioxide. Collected. The fuel components (hydrogen and carbon monoxide) after the carbon dioxide was separated by the carbon dioxide separator 3 were recycled to the fuel electrode side of the molten carbonate fuel cell.

The carbon dioxide gas collected by the carbon dioxide separation device 3 is released to produce hot carbon dioxide gas of 100 ° C., and the waste heat of the battery body in the power generation device 2 is used to produce hot water of 80 ° C. The hot water supply pipe 5 and the carbon dioxide gas supply pipe 6 shown in FIG. 4 described above were brought into contact with each other, and supplied to the customer through a piping system in which the periphery thereof was covered with a heat insulating material 7.

(Comparative Example 1) A power plant similar to that of Example 1 was assembled except that a carbon dioxide separation device was not provided.
Combined cycle power generation using NG as fuel was performed. However, the carbon dioxide supply pipe was not incorporated in the power plant because the carbon dioxide separator was not provided.

Comparative Example 2 A power plant similar to that of Example 2 was assembled except that no carbon dioxide gas separation device was provided, and power was generated by a phosphoric acid fuel cell. However, the carbon dioxide supply pipe was not incorporated in the power plant because the carbon dioxide separator was not provided.

(Comparative Example 3) Except that the carbon dioxide gas supply pipe and the hot water supply pipe were laid independently toward consumers,
A power plant similar to that of Example 3 was assembled, and power was generated by a phosphoric acid fuel cell using LNG as fuel.

(Comparative Example 4) Except that the carbon dioxide gas supply pipe and the hot water supply pipe were laid independently toward consumers,
A power plant similar to that of Example 2 was assembled, and power was generated by a molten carbonate fuel cell using LNG as fuel.

In Example 1 and Comparative Example 1, 1 MW
The power generation efficiency and carbon dioxide emission when combined cycle power generation was performed to secure the output power were examined. In addition, the hot water supply heat efficiency calculated from the difference between the carbon dioxide gas recovery rate and the hot water supply temperature and the hot water temperature at the customer was examined.
The results are shown in Table 1 below.

Further, in Examples 2 and 3 and Comparative Examples 2 to 4, the power generation efficiency and the amount of carbon dioxide emission when power was generated by the fuel cell so as to secure a power of 500 KW were examined. In addition, the hot water supply heat efficiency calculated from the difference between the carbon dioxide gas recovery rate and the hot water supply temperature and the hot water temperature at the customer was examined. The results are shown in Table 1 below.

[0035]

[Table 1]

As is apparent from Table 1, the cogeneration power plants of Examples 1 to 3 according to the present invention have a lower carbon dioxide emission and a larger heat energy than the power plants of Comparative Examples 1 to 4. It can be seen that the supply of hot water with

[0037]

As described above in detail, according to the present invention, the carbon dioxide gas accompanying the oxidation reaction of a gas turbine or a fuel cell is efficiently recovered during the power generation process, and the heated carbon dioxide gas is released during the recovery. Co-generation power generation that achieves high-efficiency, low-cost reduction of carbon dioxide emissions and supplies hot water with large heat energy to consumers by supplying it to consumers along with hot water We can provide a plant.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cogeneration power plant according to the present invention.

FIG. 2 is a schematic diagram showing another cogeneration power plant according to the present invention.

FIG. 3 is a schematic diagram showing a piping system for supplying heated carbon dioxide gas and hot water to a customer together.

FIG. 4 is a schematic diagram showing a piping system for supplying heated carbon dioxide gas and hot water to a customer.

FIG. 5 is a schematic view showing a piping system for supplying heated carbon dioxide gas and hot water to a customer.

FIG. 6 is a schematic diagram showing a piping system for supplying heated carbon dioxide gas and hot water to a customer together.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reformer, 2 ... Power generation apparatus, 3 ... Carbon dioxide separation apparatus, 4 ... Power supply line, 5 ... Hot water supply pipe 6 ... Hot carbon dioxide gas supply pipe 7 ... Heat insulation material.

Claims (2)

[Claims] 1. A first device that generates electric power and hot water by an oxidation reaction of a hydrocarbon-based fuel, and physically or chemically absorbs a carbon dioxide gas generated in a process of oxidizing the fuel by the first device. A second device containing a substance capable of recovering and heating the heated carbon dioxide and releasing the carbon dioxide; and externally accommodating the hot water and the heated carbon dioxide released from the substance. And a piping system for supplying the power to the co-generation power plant. 2. The substance contained in the second device,
2. A carbon dioxide absorbing material having a property of reacting with carbon dioxide to recover as lithium carbonate, releasing carbon dioxide, and returning to a state before the reaction of carbon dioxide.
Co-generation power plant as described.