JPH0598910A - Power generating device with carbon dioxide gas recovery device and power generating method - Google Patents

Abstract

PURPOSE:To improve efficiency of power generation without reducing power generating output even when demand of electric power is increased in the daytime by storing into a storing facility, carbon dioxide gas absorbing liquid which absorbed produced carbon dioxide gas by means of an absorbing device and regenerating carbon dioxide gas absorbing liquid stored in the storing facility, and then storing it into a storing facility for absorbing carbon dioxide gas. CONSTITUTION:Steam generated in a boiler 1 is led into a turbine power generator 2 by a line 3 so as to generate power. A tank 15 is provided as a storing facility for carbon dioxide gas absorbing liquid in which carbon dioxide gas is absorbed. A tank 16 is provided as a storing facility for regenerated carbon dioxide gas absorbing liquid. An absorbing column 7 is operated by day and by night during power generation so as to absorb carbon dioxide gas, and on the other hand, carbon dioxide gas absorbing liquid is not regenerated at the time of shortage of electric current. Carbon dioxide gas absorbing liquid including carbon dioxide gas generated in the absorbing column 7 is stored into the tank 15 in daytime, and a regenerating column 10 is operated in night so as to regenerate carbon dioxide gas absorbing liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon dioxide gas recovery device equipped with a carbon dioxide gas recovery device for recovering carbon dioxide gas contained in a combustion exhaust gas of a boiler in a thermal power generation, and a power generation method thereof.

[0002]

2. Description of the Related Art In recent years, the greenhouse effect of carbon dioxide has been pointed out as one of the causes of the global warming phenomenon, and countermeasures against it have become urgent internationally in order to protect the global environment. Sources of carbon dioxide gas cover all human activity fields that burn fossil fuels, and their emission regulations are likely to be tightened in the future. As one of the measures, targeting power generation facilities of thermal power plants that use large amounts of fossil fuels, a method of recovering carbon dioxide in the combustion exhaust gas of a boiler and storing the recovered carbon dioxide without releasing it to the atmosphere The method of doing is being actively researched.

[0003]

By the way, as a method of absorbing and recovering carbon dioxide gas contained in combustion exhaust gas, an apparatus illustrated in FIG. 2 has been conventionally proposed. In FIG. 2, only the main equipment is shown and the auxiliary equipment is omitted.

In FIG. 2, steam generated in the boiler 1 is guided to a turbine generator 2 through a line 3 to generate electric power. On the other hand, the combustion exhaust gas generated in the boiler 1 is guided to a cooling tower 5 through a line 4 and brought into contact with cooling water to be cooled, and then guided to an absorption tower 7 through a line 6. Line 8 is above the absorption tower 7.
As a result, a carbon dioxide absorbing solution, for example, an aqueous monoethanolamine solution having a concentration of about 20 to 30% by weight is supplied. The monoethanolamine aqueous solution is brought into countercurrent contact with the combustion gas, and is sent from the lower part of the tower 7 through a line 9 to a regeneration tower 10 of a regenerated liquid of the monoethanolamine aqueous solution as a monoethanolamine aqueous solution having absorbed carbon dioxide gas. Absorption tower 7
From the upper part of the above, the remaining combustion gas in which carbon dioxide gas is absorbed is released to the atmosphere through the line 11.

Regeneration tower 10 for monoethanolamine aqueous solution
In the reboiler 13, the monoethanolamine aqueous solution absorbing carbon dioxide gas is heated to regenerate the monoethanolamine aqueous solution, and is returned to the absorption tower 7 through the line 8. The carbon dioxide gas is guided to the recovery process by the line 14. If necessary, a heat exchanger may be installed in the lines 8 and 9 to perform heat exchange with each other. As a heat source of the reboiler 13, steam generated in the boiler 1 or steam on the low pressure side of the turbine generator 2 is extracted and introduced through a line 12.

In the apparatus for absorbing and recovering carbon dioxide in exhaust gas while performing thermal power generation as described above, the steam used in the reboiler 13 accounts for about 20% of the steam generated in the boiler 1. On the other hand, the power demand greatly varies depending on the time of day, and particularly during the daytime from about 10 am to about 5 pm, it is particularly large. Therefore, the issue is how to increase the amount of power generation during this period.
As described above, it takes about 2 to regenerate the monoethanolamine aqueous solution.
There was no choice but to use a relatively small amount of steam, and at that time the problem was that the amount of power generation decreased, and there was a need for improvement in this respect.

[0007]

[Means for Solving the Problems] The inventors of the present invention have made diligent studies in view of the above-mentioned circumstances when generating power while absorbing and recovering carbon dioxide contained in combustion exhaust gas discharged from a boiler. A carbon dioxide absorbing liquid that has absorbed gas, such as a storage facility for monoethanolamine aqueous solution and a storage facility for regenerated monoethanolamine aqueous solution, is installed, and the regenerator is operated during a time period when power demand is small to store in the storage facility. It was found that the above problems can be solved by regenerating an ethanolamine aqueous solution, and the present invention has been completed.

That is, the first aspect of the present invention is that a steam source boiler, a steam turbine generator, an absorption device for absorbing carbon dioxide gas in a combustion exhaust gas generated from the boiler with a carbon dioxide gas absorbing solution, and an extraction air from the boiler or turbine generator. A carbon dioxide absorbing device equipped with a carbon dioxide absorbing liquid regenerator that uses steam as a heat source is equipped with a carbon dioxide absorbing liquid storage facility and a regenerated carbon dioxide absorbing liquid storage facility. It is a power generation device equipped with a carbon dioxide recovery device.

In the second aspect of the present invention, while generating electricity by a turbine generator using a boiler as a steam source, carbon dioxide gas in combustion exhaust gas generated from the boiler is absorbed by a carbon dioxide gas absorption liquid by using an absorption device, and the next step It is a power generation method that regenerates the carbon dioxide absorption liquid by a regenerator that uses steam extracted from a boiler or a turbine generator as a heat source, and the regenerator is stopped during a time when the power demand is high and generated by the absorber during that time. The CO2 absorption liquid that has absorbed CO2 gas is stored in the storage facility, and the regeneration device is operated during times of low electricity demand to regenerate the CO2 absorption liquid stored in the storage facility and become the CO2 absorption storage facility. It is a method of generating electricity while recovering carbon dioxide, which is characterized by storing. Hereinafter, the present invention will be described in detail with reference to the drawings.

An example of the carbon dioxide recovery device-equipped power generator of the present invention is shown in FIG. In FIG. 1, only the main equipment is shown and the auxiliary equipment is omitted. If necessary, pulps, pumps, heat exchangers, etc. are provided. Note that devices having the same reference numerals as those in FIG. 2 indicate the same devices.

In FIG. 1, a tank 15 is provided as a storage facility for carbon dioxide absorption liquid that has absorbed carbon dioxide, and a tank 16 is provided as a storage facility for regenerated carbon dioxide absorption liquid. As a result, the absorption tower 7 is operated in the day and night as long as power is being generated to absorb carbon dioxide gas, but the carbon dioxide absorbent is not regenerated during a time period when power is insufficient, for example, in the daytime. Therefore, during the daytime, steam extraction by the line 12 is not performed, and the power generation amount can be increased accordingly. During that time, the carbon dioxide absorbing liquid containing carbon dioxide generated in the absorption tower 7 is stored in the tank 15, and the regeneration tower 10 is operated to perform regeneration when the electric power demand decreases, for example, at night. Since the regeneration tower 10 is operated intermittently in this manner, it is necessary to provide the tank 16 for storing the regenerated carbon dioxide absorbing liquid.

Although the capacity of each tank varies depending on the difference in power demand between daytime and nighttime, it is preferable that each tank has a capacity equal to or more than 1/3 to 1/2 day of the treatment of the absorption tower 7 and the regeneration tower 10.

As the carbon dioxide absorbing solution, a hindered amine compound, an alkaline aqueous solution of potassium carbonate, an alkanolamine aqueous solution of monoethanolamine, diethanolamine, triethanolamine, methyldiethanolamine, diisopropanolamine, diglycolamine, or the like. Although a mixed aqueous solution can be mentioned, a monoethanolamine aqueous solution is preferably used.

In the present invention, unlike the prior art illustrated in FIG. 2, it is necessary to newly install the tanks 15 and 16. However, it should be especially noted that the economic merit of increasing power generation during the daytime when electricity demand is high is far greater than the cost associated with the construction of new tanks. According to the calculation by the present inventors at the present time, for example, 60
In a 0 MW power plant, it is said that the power generation equipment cost is about 100,000 yen per kW, and about 30% of the low-pressure steam is used for regeneration of the carbon dioxide absorption liquid. If the power generation amount of about 10% can be increased by adopting, the facility cost of about 6 billion yen can be saved. On the other hand, if two tanks of about 40,000 m ³ for a carbon dioxide absorbing liquid, for example, an aqueous solution of monoethanolamine, are added, the equipment cost is about 1 billion yen, which enables a significant cost reduction.

[0015]

As described in detail above, according to the present invention, when the carbon dioxide absorbing device is operated to generate electricity while removing carbon dioxide, the power generation output is lowered even when the daytime power demand increases. It became possible to deal efficiently without doing this.

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of a carbon dioxide recovery device-equipped power generation device of the present invention.

FIG. 2 is an explanatory diagram of an example of a conventional carbon dioxide gas recovery device-attached power generation device.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Zenji Hotta 3-3-22 Nakanoshima, Kita-ku, Osaka City Kansai Electric Power Co., Inc. (72) Kenji Kobayashi 3-22-3 Nakanoshima, Kita-ku, Osaka Kansai Denryoku Co., Ltd. (72) Inventor Kunihiko Yoshida 3-11-20 Wakaoji, Amagasaki City Kansai Electric Power Co., Inc. Research Institute (72) Inventor Shigeru Shimojo 3-11-20 Wakaoji, Amagasaki Kansai (72) Inventor Mutsunori Karazaki 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd. (72) Inventor Masaki Iijima 2-5-1, Marunouchi, Chiyoda-ku, Tokyo No. Sanryo Heavy Industries Co., Ltd. (72) Inventor Toru Seto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries Ltd. Hiroshima Research Institute (72) Inventor Hikari KaoruAkira Hiroshima Nishi-ku Kan'onshin-cho, chome No. 6 No. 22 Mitsubishi Heavy Industries, Ltd. Hiroshima within the Institute

Claims (2)

[Claims] 1. A steam source boiler, a turbine generator using steam, an absorption device for absorbing carbon dioxide gas in combustion exhaust gas generated from the boiler with a carbon dioxide gas absorption liquid, and steam extracted from the boiler or turbine generator as a heat source. In a power generation device equipped with a carbon dioxide gas absorption device comprising a regeneration device for carbon dioxide gas absorption liquid, a storage facility for carbon dioxide gas absorption liquid that absorbs carbon dioxide gas and a storage facility for regenerated carbon dioxide gas absorption liquid are provided. Power generator with carbon dioxide recovery device. 2. The carbon dioxide gas in the combustion exhaust gas generated from the boiler is absorbed by the carbon dioxide absorption liquid by using an absorption device while generating power by the turbine generator using the boiler as a steam source, and the boiler or turbine power generation is performed in the next step. This is a power generation method in which the carbon dioxide absorbing liquid is regenerated by a regenerator that uses steam extracted from the machine as a heat source, and the regenerator is stopped during times of high power demand, during which the carbon dioxide gas generated by the absorber is absorbed. The carbon dioxide absorbing liquid is stored in a storage facility, and the regeneration device is operated during a time when the power demand is small, and the carbon dioxide absorbing liquid stored in the storage facility is regenerated and stored in the carbon dioxide absorbing storage facility. A method of generating electricity while collecting carbon dioxide gas.