JPH054043A - Treating device for carbon dioxide - Google Patents

Abstract

PURPOSE:To decrease the carbon dioxide to be discharged into the atm. by providing a cooling pipe enclosing a transporting pipe for forming a carbon dioxide clathrate hydrate by bringing the sea water and the carbon dioxide into reaction. CONSTITUTION:Exhaust gases contg. the carbon dioxide discharged from a combustion furnace 1 are separated and concentrated to the liquefied carbon dioxide by a carbon dioxide separator 2. This carbon dioxide is transported to a liquefied carbon dioxide storage tank 5 on a prescribed off-shore base 4 by a transporting ship 3. The liquefied carbon dioxide from the liquefied carbon dioxide storage tank 5 and the taken-in sea water are pressurized and mixed in the transporting pipe 7 by force feed pump 6 to progress the reaction to form the carbon dioxide clathrate hydrate. Further, the reaction heat generated on progression of the reaction to form the carbon dioxide clathrate hydrate is heat-exchanged and removed by the deep layer sea water sucked up by a sea water intake pump 9 into the cooling pipe 8 enclosing the transporting pipe 7. The formed carbon dioxide clathrate hydrate 10 is released and dispersed into the deep sea of the range of carbon dioxide clathrate hydrate forming conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for treating carbon dioxide gas, and more particularly to an apparatus for treating carbon dioxide gas in combustion exhaust gas to reduce carbon dioxide gas discharged to the atmosphere.

[0002]

2. Description of the Related Art Carbon dioxide in exhaust gas generated by combustion of fossil fuels such as power generation boilers and industrial boilers has been conventionally released into the atmosphere without any treatment, and carbon dioxide gas is separated from combustion exhaust gas. At present, almost no industrial means for reducing the amount (concentration) of carbon dioxide gas emitted from the plant is taken.

[0003]

The concentration of carbon dioxide in the atmosphere was 1315: 315 ppm, 1970: 325 ppm,
1980: Gradually increased to 335 ppm and now about 350
It is said to be ppm. The cause of the increase in carbon dioxide concentration is considered to be the total result of various factors including timber logging, desertification of forests, destruction of coral reefs and artificial increase. It is inferred that carbon dioxide emission from fossil fuel combustion is a major factor in the increase in atmospheric concentration because the tendency of the gas concentration to increase over time is similar.

An increase in carbon dioxide in the atmosphere causes an increase in the temperature of the atmosphere, which causes a warming of the climate or a greenhouse effect of the earth. As a result, the Antarctic iceberg melts, the seawater temperature rises, the seawater level rises, forest desertification, food shortages occur. And so on, which will endanger future human life. If we continue to burn fossil fuels under the current conditions and release the carbon dioxide gas in the exhaust gas, we can predict that the carbon dioxide concentration in the atmosphere will surely increase in the future.

In order to reduce the increase in carbon dioxide in the atmosphere, all or part of the carbon dioxide contained in the combustion exhaust gas of fossil fuels is separated and recovered, and the carbon dioxide is pumped to the deep sea, where seawater and liquefied carbon dioxide are stored. The method of depositing and forming the crystalline compound (referred to as carbon dioxide gas clathrate hydrate) has been proposed. This carbon dioxide gas clathrate hydrate is stable without separation under deep sea environmental conditions, and since it has a larger specific gravity than seawater, it does not float.

However, it has been confirmed that reaction heat (about 100 kcal / kg) is generated in this precipitation formation reaction, and in the treatment of a large amount of carbon dioxide gas, the ecological environment is destroyed due to the rise in seawater temperature accompanying the reaction, and further the ambient temperature. There is a possibility of decomposition of carbon dioxide clathrate hydrate due to the rise.

[0007]

The present invention extends to the deep sea,
And a transport pipe for reacting seawater and carbon dioxide to produce carbon dioxide gas clathrate hydrate, and a cooling pipe for bending the transport pipe and sucking deep-sea low-temperature seawater. It is a carbon dioxide processing device.

That is, according to the present invention, in the transport pipe to the deep sea, seawater and carbon dioxide are reacted to precipitate and generate carbon dioxide gas clathrate hydrate. Is a device for stably dispersing carbon dioxide gas clathrate hydrate in the deep sea.

The present invention is an apparatus for treating high-concentration carbon dioxide gas or liquefied carbon dioxide gas, and the produced carbon dioxide gas clathrate hydrate is stable without being decomposed under deep-sea environmental conditions and has a specific gravity larger than that of seawater. Therefore, it will not surface. In addition, since there is no local generation of heat of reaction in the deep sea, there is no possibility of destruction of the ecological environment due to the rise in seawater temperature due to the heat of reaction and decomposition of carbon dioxide clathrate hydrate due to rise in ambient temperature in the deep sea. ..

[0010]

The principle of producing carbon dioxide gas clathrate hydrate by mixing carbon dioxide gas and seawater will be described with reference to FIG. Figure 2
CO ₂ (vertical axis logarithmic scale pressure, and the horizontal axis the temperature) into and H ₂
The phase equilibrium state of O is shown, which represents the state (gas, liquid, solid) in which CO ₂ and H ₂ O exist depending on the temperature and pressure conditions. (12.4 atm or more at 0 ° C, 44 at 10 ° C)
At at least atm), CO ₂ and H ₂ O are under the condition that a clathrate hydrate is produced by the following reaction. CO ₂ +53/4 H ₂ O = CO ₂・ 5 ・ 3 / 4H ₂ O (equilibrium reaction)

This hydrate has a crystal structure in which CO ₂ molecules enter into a crystal of water (skeleton of a three-dimensional structure of dodecahedron or tetradecahedron) and is a solidified substance which is hardly soluble in water. This hydrate has a specific gravity of 1.11 and has deep sea water (1.
Although it is larger than the specific gravity of 05 to 1.07), if it deviates from the temperature and pressure range shown above (for example, in water having a temperature of 10 ° C. or higher), CO ₂ gas is re-separated.

FIG. 3 shows a typical ocean depth, seawater temperature, and salt concentration. When the depth becomes deeper than about 600 m, 10
Since the water temperature is below ℃, the conditions for carbon dioxide gas clathrate hydrate formation can be satisfied in the deep sea with this water depth.
On the other hand, since a pressure of 1 atm is applied every 10 m of water depth, there is a pressure of 50 atm in the deep sea with a water depth of 500 m, which satisfies the clathrate generation condition.

Therefore, seawater and carbon dioxide are pumped to the deep sea by a transport pipe to cause precipitation and formation of carbon dioxide clathrate hydrate in the pipe, as well as destruction of the ecological environment due to temperature rise accompanying the production reaction and ambient temperature in the deep sea. In order to eliminate the possibility of carbon dioxide clathrate hydrate decomposition due to rising, the heat of reaction formation is removed by low-temperature deep seawater during transport to the deep sea, and carbon dioxide clathrate hydrate is stably dispersed in the deep sea. Make it possible.

As can be seen from FIG. 3, deep seawater is a rich source of low-temperature water. Therefore, the deep seawater as a low-temperature source is used to remove the heat of formation of carbon dioxide gas clathrate hydrate. Is.

[0015]

EXAMPLE An example of an apparatus for treating carbon dioxide gas in a combustion furnace exhaust gas according to the present invention will be described with reference to FIG. In FIG. 1, the exhaust gas containing carbon dioxide gas discharged from the combustion furnace 1 is separated and concentrated by a carbon dioxide gas separation device 2 into liquefied carbon dioxide gas, which is transported by a transport ship 3 to a liquefied carbon dioxide storage tank 5 at a predetermined offshore base 4. Transport to.

The liquefied carbon dioxide gas from the liquefied carbon dioxide gas storage tank 5 and the seawater taken in are pressurized and mixed in the transport pipe 7 by the pressure pump 6 to promote the carbon dioxide gas clathrate hydrate formation reaction and also to generate the carbon dioxide gas class. The reaction heat generated with the progress of the rate hydrate formation reaction is removed by heat exchange with the deep seawater sucked up by the seawater intake pump 9 in the cooling pipe 8 surrounding the transportation pipe 7, and the generated carbon dioxide gas class The rate hydrate 10 is released / dispersed in the deep sea within the range of carbon dioxide clathrate hydrate production conditions.

The temperature inside the cooling pipe 8 and the pressure inside the pressure pump 6 are adjusted by a cooling water thermometer 11 attached to each part of the cooling pipe 8, a transport pipe internal thermometer 12 attached to each part of the transport pipe 7, and a transport pipe. The data of the pressure gauge 13 is processed by the computer 14, and the load of the seawater intake pump 9 that takes in the cooling seawater in the cooling pipe 8 through the temperature controller 15 and the inside of the transport pipe 7 through the pressure controller 16 Pressure pump 6 for setting pressure
It is preferable to set the load amount of.

In this way, the apparatus for treating carbon dioxide gas of the present invention, which utilizes the low-temperature seawater in the deep layer for the progress of the reaction and the removal of the heat of reaction, directly feeds the carbon dioxide gas into the deep sea to obtain the carbon dioxide gas clathrate hydrate. Carbon dioxide clathrate hydrate release associated with the generation and dispersal of carbon dioxide. Ecological environmental damage caused by temperature rise due to reaction heat and carbon dioxide due to ambient temperature rise in the sea area where carbon dioxide clathrate hydrate is dispersed and released. The decomposition of gas clathrate hydrate is eliminated, stable carbon dioxide gas clathrate hydrate dispersion is possible, and carbon dioxide can be fixed semipermanently in the deep sea.

The above has described an embodiment in which carbon dioxide gas is liquefied and liquefied carbon dioxide gas is sent to deep water together with seawater through a transport pipe. However, when there is land where low temperature seawater is directly taken from the deep sea, carbon dioxide gas needs to be liquefied. Instead, it is also possible to supply high-concentration carbon dioxide gas directly to the transport pipe.

[0020]

According to the present invention, the progress of the reaction and the removal of the heat of reaction are carried out in the transport pipe by using the deep sea water of low temperature, so that the carbon dioxide gas is directly pumped into the deep sea, and the carbon dioxide gas clathrate hydrate is hydrated. Carbon dioxide clathrate hydrate release associated with the generation and dispersal of chemicals Deterioration of ecological environment caused by temperature rise due to reaction heat and increase in ambient temperature of carbon dioxide clathrate hydrate dispersed release sea area The decomposition of carbon dioxide gas clathrate hydrate is eliminated, stable carbon dioxide gas clathrate hydrate can be dispersed, and carbon dioxide gas can be fixed semipermanently in the deep sea.

Further, energy can be saved by utilizing a deep source of low temperature seawater, which is abundant low temperature source of nature.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a carbon dioxide gas processing apparatus of the present invention.

FIG. 2 is an explanatory view of the principle of carbon dioxide gas clathrate hydrate formation of the present invention.

FIG. 3 is a chart showing the relationship between seawater depth and temperature of a typical ocean.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshio Inoue 20 Kitakanzan, Otakamachi, Midori-ku, Nagoya-shi 1 Chubu Electric Power Co., Inc. Electric Power Technology Research Laboratory (72) Inventor Sakai Matsunari Nagoya-shi Chubu Electric Power Co., Inc. 20-20 Kitakanyama, Otakamachi, Midori-ku Chubu Electric Power Co., Inc. (72) Inventor Akira Saji 1-20 Chubu Electric Power Co., Ltd. (72) Inventor, Tadaaki Tanai, 1-1, Niihama, Niihama, Arai-cho, Takasago-shi, Hyogo Prefecture (72) In-house, Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Masaaki Negoro, 2-chome, Niihama, Arai-cho, Takasago, Hyogo Prefecture No. 1 Mitsubishi Heavy Industries, Ltd. Takasago Research Institute (72) Inventor Yu Kawada 2-1-1 Nihama, Arai-cho, Takasago, Hyogo Prefecture Mitsubishi Heavy Industries Stock Association Takasago Research Institute (72) Inventor Mitsuru Kitamura 1-1-1, Wadazaki, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Toshio Haneda 1-1, Wadazaki, Hyogo-ku, Kobe-shi, Hyogo No. 1 Mitsubishi Heavy Industries, Ltd. Inside Kobe Shipyard

Claims (1)

Claim: What is claimed is: 1. A transport pipe that extends to the deep sea and that reacts seawater and carbon dioxide to generate carbon dioxide gas clathrate hydrate; An apparatus for treating carbon dioxide, comprising a cooling pipe for sucking up carbon dioxide.