JP2007069059A - Gas treatment method and system and carbon dioxide recovery method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas treatment method capable of efficiently removing a harmful gas component from a gas containing nitrogen oxide or sulfur oxide or both of the oxides and efficiently recovering carbon dioxide, and a gas treatment system. <P>SOLUTION: Nitrogen oxide or sulfur oxide is liquefied or solidified to remove it from the gas by cooling the gas containing the harmful gas component to a temperature not solidifying carbon dioxide but liquefying or solidifying nitrogen oxide or sulfur oxide. Carbon dioxide contained in the gas is solidified by cooling the gas from which nitrogen oxide or sulfur oxide is removed to a temperature for solidifying carbon dioxide and is deposited on an inner surface of a vessel fed with the gas. The vessel is air-tightly closed and the inside of the vessel is pressurized to a pressure or higher than a pressure at which the carbon dioxide can be liquefied. The liquid carbon dioxide is introduced to the vessel to dissolve the solidified carbon dioxide existing in the vessel in the liquid carbon dioxide. The dissolved carbon dioxide is discharged to the outside of the vessel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas processing method and system. The present invention also relates to a carbon dioxide recovery method and system.

  Hazardous gas components such as sulfur oxides and nitrogen oxides contained in exhaust gas discharged from coal-fired boilers at power plants and chemical plants, blast furnaces, coke ovens, converters, etc. at steelworks, for example, wet desulfurization treatment It is separated and removed by using a denitration treatment apparatus using a denitration apparatus or a denitration catalyst. Also, a so-called physical adsorption method using activated carbon is known as a more efficient method for separating and removing harmful gas components.

  On the other hand, the amount of carbon dioxide in the atmosphere has increased recently, and the relationship with the rise in atmospheric temperature, called the greenhouse effect, has become a problem. The cause of the increase in the amount of carbon dioxide generation is mostly caused by the combustion of fossil fuels. For this reason, power plants, chemical plants, and the like are required to prevent carbon dioxide contained in exhaust gas from being discharged into the atmosphere as much as possible.

  In such circumstances, for example, regarding the treatment of exhaust gas discharged from coal-fired boilers, blast furnaces, coke ovens, converters, etc. in steelworks, while removing harmful gas components such as nitrogen oxides and sulfur oxides efficiently Further, it is necessary to efficiently collect carbon dioxide, and there is a need for an exhaust gas treatment system that can efficiently and continuously perform removal of harmful gas components and carbon dioxide recovery as a series of treatments.

  For example, regarding the treatment of exhaust gas discharged from an LNG-fired boiler, it is necessary to efficiently remove harmful gas components such as nitrogen oxides and efficiently recover carbon dioxide. A mechanism for efficiently and continuously performing carbon recovery as a series of processes is required.

  Regarding the treatment of these exhaust gases, it is necessary to efficiently remove harmful gas components such as nitrogen oxides and sulfur oxides, and also to efficiently collect carbon dioxide. Removal of harmful gas components and carbon dioxide recovery There is a need for an exhaust gas treatment system that can efficiently and continuously be performed as a series of treatments.

  Here, in the technology for recovering carbon dioxide contained in the exhaust gas, the technology for separating carbon dioxide from the exhaust gas is important as an elemental technology for that purpose. As such a technique, a technique is disclosed in which carbon dioxide in exhaust gas is solidified and separated as dry ice, and further heated and pressurized to form liquid carbon dioxide (see, for example, Patent Document 1). The method disclosed in this document can be implemented by, for example, the method shown in FIG. In the method shown in the figure, first, a gas 1103 for separating carbon dioxide is circulated inside a heat exchanger tube 1102 of a heat exchanger in which a refrigerant 1100 is circulated on the outer side, whereby carbon dioxide contained in the gas. Is dried ice (solidified) and collected in a collection container 1104. Then, the dry ice 1105 collected in the collection container 1104 is transferred from the collection container 1104 to the dry ice liquefier 1106 and recovered as liquid carbon dioxide 1107. The collected dry ice 1105 is liquefied for convenience of storage and transportation.

In the method shown in FIG. 1, dry ice is deposited inside the heat transfer tube 1102. For this reason, the pipe line of the heat exchanger tube 1102 is blocked by the deposited dry ice, and there is a problem that continuous operation or automatic operation of the apparatus is difficult. In addition, since the collection container 1104 that is a solidification unit and the dry ice liquefaction device 1106 that is a liquefaction unit are configured as separate devices, a mechanism for conveying carbon dioxide from the collection container 1104 to the dry ice liquefaction device 1106. Is also necessary. In other words, in the method shown in FIG. 1, the process of separating carbon dioxide from the gas cannot be operated continuously and efficiently, especially when it is intended to be applied to a large amount of exhaust gas generation sources such as thermal power plants and steelworks. However, it is not necessarily sufficient in terms of performance.
JP 2000-317302 A

  The present invention has been made in view of the background as described above, and efficiently removes harmful gas components from a gas containing nitrogen oxide and / or sulfur oxide, and efficiently removes carbon dioxide. It is an object of the present invention to provide a gas processing method and system that can be recovered.

  In the gas treatment method according to the present invention, the gas containing carbon dioxide is cooled at a temperature at which carbon dioxide is solidified, so that the carbon dioxide contained in the gas is solidified, and the inside of the container into which the gas is introduced. Adhering to the surface, sealing the container, pressurizing the interior of the container above the pressure at which carbon dioxide can take a liquid state, introducing liquid carbon dioxide into the container, and solidifying the solid present in the container A part or all of carbon dioxide is dissolved in the liquid carbon dioxide, part or all of the dissolved carbon dioxide is discharged out of the container, and the discharged dissolved carbon dioxide is recovered. To do.

  In the gas treatment method according to the present invention, the gas further containing one of nitrogen oxides and sulfur oxides does not solidify carbon dioxide, but liquefies or solidifies the nitrogen oxides or sulfur oxides. A first step of liquefying or solidifying nitrogen oxides or sulfur oxides contained in the gas by cooling to a temperature and removing them from the gas; and the gas from which the nitrogen oxides or sulfur oxides have been removed is carbon dioxide. By cooling to the second temperature for solidifying the carbon dioxide contained in the gas from which the nitrogen oxides or sulfur oxides have been removed, the gas from which the nitrogen oxides or sulfur oxides have been removed is supplied. The inner surface of the container is sealed, the container is sealed, the inside of the container is pressurized to a pressure higher than the pressure at which carbon dioxide can take a liquid state, and the liquid carbon dioxide is introduced into the container. Including a second step of dissolving a part or all of the solidified carbon dioxide present in the container in the liquid carbon dioxide and discharging a part or all of the dissolved carbon dioxide to the outside of the container. Features.

  In the gas treatment method, in the first step, the gas is circulated through a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxide or sulfur oxide is liquefied or solidified, thereby oxidizing the nitrogen contained in the gas. An object or sulfur oxide is removed from the gas.

  In the gas treatment method, the cooling medium containing the nitrogen oxide or sulfur oxide separated from the gas in the first step is vaporized, but the nitrogen oxide or sulfur oxide is vaporized. Includes a third step of separating the nitrogen oxide or sulfur oxide and the cooling medium by raising the temperature to a temperature at which vaporization is not caused.

  Furthermore, the gas treatment method includes a fourth step of reusing the cooling medium separated from the nitrogen oxide or sulfur oxide as the cooling medium for circulating the gas.

  In the gas treatment method according to the present invention, the gas further containing nitrogen oxides and sulfur oxides is cooled to a first temperature that does not solidify carbon dioxide but liquefies or solidifies the nitrogen oxides and sulfur oxides. A first step of liquefying or solidifying nitrogen oxides and sulfur oxides contained in the gas and removing them from the gas; and a step of solidifying carbon dioxide from the gases from which the nitrogen oxides and sulfur oxides have been removed. By cooling to a temperature of 2, the carbon dioxide contained in the gas from which the nitrogen oxides and sulfur oxides have been removed is solidified, and the inside of the container to which the gas from which the nitrogen oxides and sulfur oxides have been removed has been supplied The container is sealed, the inside of the container is pressurized to a pressure higher than the pressure at which carbon dioxide can take a liquid state, liquid carbon dioxide is introduced into the container, A second step of dissolving a part or all of the solidified carbon dioxide existing in the liquid carbon dioxide and discharging a part or all of the dissolved carbon dioxide out of the container. .

  In the gas treatment method, in the first step, the gas is circulated through a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxides and sulfur oxides are liquefied or solidified, thereby oxidizing nitrogen contained in the gas. The product and sulfur oxide are removed from the gas.

  In the gas treatment method, the cooling medium containing the nitrogen oxides and sulfur oxides separated from the gas in the first step is vaporized, but the nitrogen oxides and sulfur oxides are vaporized. Includes a third step of separating the nitrogen oxide and sulfur oxide and the cooling medium by raising the temperature to a temperature at which vaporization is not caused.

  Furthermore, the gas treatment method includes a fourth step of reusing the cooling medium separated from the nitrogen oxide and sulfur oxide as the cooling medium through which the gas is circulated.

  Further, in the gas treatment method, the nitrogen oxides and sulfur oxides separated from the gas in the first step are heated to a temperature at which sulfur oxides are vaporized but nitrogen oxides are not vaporized. And a fifth step of separating sulfur oxide and nitrogen oxide.

  In this gas treatment method, the cooling medium includes, for example, any of dimethyl ether, methanol, ethanol, toluene, and ethylbenzene.

  Further, in this gas treatment method, the container has a refrigerant circulation device that circulates a refrigerant having a temperature equal to or lower than a temperature at which carbon dioxide is solidified, and the gas is brought into contact with the outside of the refrigerant circulation device. It is characterized by cooling.

  Here, it is preferable that the said refrigerant | coolant distribution | circulation apparatus is tubular, for example, and is provided meandering inside the said container.

  In the gas treatment method, the first step includes a step of separating moisture contained in the gas from the gas.

  Furthermore, in this gas processing method, the gas may be an exhaust gas discharged from an LNG-fired boiler, for example.

  In this gas processing method, the liquid carbon dioxide is supplied from a carbon dioxide storage tank to the container, and the discharged dissolved carbon dioxide is recovered into the carbon dioxide storage tank.

  Moreover, in this gas processing method, the pressure in the said carbon dioxide storage tank is the same as the pressure in the said container, It is characterized by the above-mentioned.

  Furthermore, in the present gas treatment method, the pressure is 5.11 atm or more.

  The gas processing apparatus according to the present invention cools a gas containing carbon dioxide at a temperature at which carbon dioxide is solidified, so that carbon dioxide contained in the gas is solidified, and the gas inside the container into which the gas is introduced is contained. Adhering to the surface, sealing the container, pressurizing the interior of the container above the pressure at which carbon dioxide can take a liquid state, introducing liquid carbon dioxide into the container, and solidifying the solid present in the container A part or all of carbon dioxide is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is discharged out of the container.

  Moreover, the gas processing apparatus concerning this invention is a gas processing apparatus for removing the said carbon dioxide from the gas containing carbon dioxide, Comprising: The 1st inlet_port | entrance for supplying the said gas containing carbon dioxide, , A first outlet for discharging gas after removing part or all of the carbon dioxide, a second inlet for supplying liquid carbon dioxide, and solidified dioxide dissolved by the liquid carbon dioxide A container having a second outlet for discharging carbon; and a cooling device for solidifying the carbon dioxide, wherein the container controls the amount of the gas supplied from the first inlet. Means for controlling, means for controlling the amount of gas discharged from the first outlet, supply means for supplying the liquid carbon dioxide from the second inlet, and the second outlet More dissolved A discharge means for discharging the solidified carbon dioxide; a recovery means for recovering the dissolved carbon dioxide discharged from the second outlet; and a pressure applying means for applying pressure to the container. It is characterized by.

  In the present gas treatment device, the cooling device is a refrigerant circulation device for circulating a refrigerant having a temperature equal to or lower than a temperature at which carbon dioxide is solidified.

  Here, it is preferable that the said refrigerant | coolant distribution | circulation apparatus is a tubular shape, for example, and is provided meandering inside the said container.

  In the gas treatment system according to the present invention, a gas containing carbon dioxide and one of nitrogen oxides and sulfur oxides does not solidify carbon dioxide, but liquefies or solidifies the nitrogen oxides or sulfur oxides. A first apparatus for liquefying or solidifying nitrogen oxides or sulfur oxides contained in the gas and removing them from the gas by cooling to a temperature; and a gas from which the nitrogen oxides or sulfur oxides have been removed Is cooled at a second temperature at which carbon dioxide is solidified to solidify carbon dioxide contained in the gas from which the nitrogen oxides or sulfur oxides have been removed, thereby removing the nitrogen oxides or sulfur oxides. Is attached to the inner surface of the container, and the container is sealed, and the inside of the container is pressurized to a pressure higher than the pressure at which carbon dioxide can take a liquid state. A part of the solidified carbon dioxide present in the container is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is discharged out of the container. It is characterized by comprising two devices.

  The gas treatment system according to the present invention is a gas treatment system for removing carbon dioxide and nitrogen oxides or sulfur oxides from a gas containing carbon dioxide and nitrogen oxides or sulfur oxides. The gas processing system includes a first device and a second device, the first device for supplying the gas containing carbon dioxide and nitrogen oxide or sulfur oxide. A third inlet, a third outlet for discharging the gas after removing part or all of the nitrogen oxides or sulfur oxides, and a third outlet for discharging the nitrogen oxides or sulfur oxides A first container having four outlets and a first cooling device for liquefying or solidifying the nitrogen oxide or sulfur oxide, and the second device is discharged from the third outlet. Containing carbon dioxide A first inlet for supplying gas, a first outlet for discharging gas after removing part or all of the carbon dioxide, and a second inlet for supplying liquid carbon dioxide , A second outlet for discharging solid carbon dioxide dissolved by the liquid carbon dioxide, a second container having a pressure applying means for applying pressure, and a second container for solidifying the carbon dioxide. And the first container controls the amount of the gas supplied from the third inlet and the amount of the gas discharged from the third outlet. Means for controlling the amount of gas containing carbon dioxide supplied from the first inlet, and the second container is configured to control the amount of gas discharged from the first outlet. Means for controlling the amount and said second inlet A supply means for supplying the liquid carbon dioxide Ri, characterized in that it comprises a discharging means for discharging the carbon dioxide the solidified dissolved from the second outlet.

  In the gas treatment system, the first cooling device contains the carbon dioxide and the nitrogen oxide or sulfur oxide in a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxide or sulfur oxide is liquefied or solidified. In this case, nitrogen gas or sulfur oxide contained in the gas is removed from the gas by circulating the gas.

  In addition, the present gas treatment system vaporizes the cooling medium containing nitrogen oxide or sulfur oxide separated from the gas by the first device, but the nitrogen oxide and sulfur oxide. The apparatus includes a device for separating the nitrogen oxide or sulfur oxide and the cooling medium by raising the temperature to a temperature at which vaporization is not caused.

  In the gas treatment system according to the present invention, the gas containing carbon dioxide, nitrogen oxide, and sulfur oxide is brought to a first temperature that does not solidify carbon dioxide but liquefies or solidifies the nitrogen oxide and sulfur oxide. A first apparatus for liquefying or solidifying nitrogen oxides and sulfur oxides contained in the gas and removing them from the gas by cooling, and a gas from which the nitrogen oxides and sulfur oxides have been removed, By cooling at a second temperature for solidifying carbon dioxide, carbon dioxide contained in the gas from which the nitrogen oxides and sulfur oxides have been removed is solidified, and the gas from which the nitrogen oxides and sulfur oxides have been removed is introduced. The container is attached to the inner surface of the container, the container is sealed, the inside of the container is pressurized to a pressure higher than the pressure at which carbon dioxide can take a liquid state, and the liquid carbon dioxide is introduced into the container. And a second apparatus for dissolving part or all of the solidified carbon dioxide present in the container in the liquid carbon dioxide and discharging part or all of the dissolved carbon dioxide to the outside of the container. It is characterized by providing.

  A gas treatment system according to the present invention is a gas treatment system for removing the carbon dioxide, nitrogen oxide, and sulfur oxide from a gas containing carbon dioxide, nitrogen oxide, and sulfur oxide. The gas treatment system includes a first device and a second device, wherein the first device supplies a third gas for supplying the gas containing the carbon dioxide, nitrogen oxide, and sulfur oxide. , A third outlet for exhausting the gas after removing part or all of the nitrogen oxides and sulfur oxides, and a fourth outlet for exhausting the nitrogen oxides and sulfur oxides A first container having an outlet; and a first cooling device for liquefying or solidifying the nitrogen oxides and sulfur oxides, wherein the second device is discharged from the third outlet. Supply gas containing carbon dioxide A first inlet for discharging the gas after removing part or all of the carbon dioxide, a second inlet for supplying liquid carbon dioxide, and the liquid dioxide A second outlet for discharging solid carbon dioxide dissolved by carbon, a second container having pressure applying means for applying pressure, and a second cooling device for solidifying the carbon dioxide The first container includes means for controlling the amount of the gas supplied from the third inlet and means for controlling the amount of the gas discharged from the third outlet. And the second container controls means for controlling the amount of gas containing carbon dioxide supplied from the first inlet and the amount of gas discharged from the first outlet. And means for the liquid from the second inlet A supply means for supplying carbon dioxide, characterized in that it comprises a discharging means for discharging the carbon dioxide the solidified dissolved from the second outlet.

  In the gas treatment system, the first cooling device contains the carbon dioxide, nitrogen oxide, and sulfur oxide in a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxide and sulfur oxide are liquefied or solidified. In this case, nitrogen gas and sulfur oxide contained in the gas are removed from the gas by circulating the gas.

  In addition, the present gas treatment system vaporizes the cooling medium containing nitrogen oxides and sulfur oxides separated from the gas by the first device, but the nitrogen oxides and sulfur oxides are vaporized. The apparatus includes a device for separating the nitrogen oxide and sulfur oxide from the cooling medium by raising the temperature to a temperature at which vaporization is not caused.

  Furthermore, the present gas treatment system is configured such that the gas contains nitrogen oxides and sulfur oxides, and the nitrogen oxides and sulfur oxides separated from the gas by the first device vaporize the sulfur oxides. The oxide includes a device for separating the sulfur oxide and the nitrogen oxide by raising the temperature to a temperature at which the oxide is not vaporized.

  In addition, the gas processing system includes a device that reuses the cooling medium separated from the gas as the cooling medium for circulating the gas.

  Further, in the gas processing system, the cooling medium includes, for example, any of dimethyl ether, methanol, ethanol, toluene, and ethylbenzene.

  In the present gas treatment system, the second cooling device is a refrigerant circulation device for circulating a refrigerant having a temperature equal to or lower than a temperature at which carbon dioxide is solidified.

  Here, it is preferable that the said refrigerant | coolant distribution | circulation apparatus is a tubular shape, for example, and is provided meandering inside the said 2nd container.

  Further, the gas processing system supplies the liquid carbon dioxide and collects the dissolved and solidified carbon dioxide discharged from the second outlet, and stores the dissolved carbon dioxide. The carbon dioxide storage tank is provided.

  In addition, the gas processing system includes an adjusting unit that adjusts the pressure of the carbon dioxide storage tank and the pressure in the dry ice recovery container to be the same.

  Furthermore, in the present gas treatment system, the pressure is, for example, 5.11 atm or more.

  The present invention provides a gas processing method and system capable of efficiently removing harmful gas components and efficiently recovering carbon dioxide from a gas containing nitrogen oxides and / or sulfur oxides. Will be able to.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a gas processing system (hereinafter referred to as a gas processing system) according to the present invention will be described in detail with reference to the accompanying drawings. This processing system includes a harmful gas recovery system for removing harmful gas from the gas to be processed, and a carbon dioxide recovery system for recovering carbon dioxide from the gas processed by the harmful gas recovery device. Since these systems can be designed independently, the configuration of each system will be described separately below.

<Toxic gas recovery system and recovery method>
= First embodiment =
FIG. 2 shows a schematic configuration of a gas processing system described as the first embodiment of the present invention. According to this gas treatment system, nitrogen oxides and sulfur oxides emitted from exhaust gas generation sources 10 such as coal-fired boilers / heavy oil fired boilers in power plants and chemical plants, blast furnaces, coke ovens, converters, etc. in steelworks. For exhaust gas containing harmful gas components such as substances, not only can moisture and harmful gas components contained in the exhaust gas be efficiently and reliably removed, but also carbon dioxide (CO ₂ ) contained in the exhaust gas can be efficiently and reliably recovered. In particular, it can be suitably applied when the toxic gas contains sulfur oxides.

  In the exhaust gas treatment system of the present embodiment, first, as a pre-process, exhaust gas (gas) containing harmful gas components such as nitrogen oxides and sulfur oxides discharged from the exhaust gas generation source 10 is converted into a heat exchanger 11 and a condenser. (Condenser) Cooled to room temperature by introducing it into industrial water contained in 13.

  Next, in the first step, the exhaust gas cooled to about room temperature is not liquefied or solidified in the dehydration tower 17, but the moisture, nitrogen oxides, and sulfur oxides contained in the exhaust gas are liquefied or solidified. By cooling to a first temperature that solidifies (for example, −90 ° C.), only moisture, nitrogen oxides, and sulfur oxides are liquefied or solidified and separated from the exhaust gas. Further, as a second step, the exhaust gas from which moisture, nitrogen oxides, and sulfur oxides have been removed is introduced into the carbon dioxide recovery device 30, where the carbon dioxide contained in the exhaust gas is cooled and solidified, and then liquid Carbon dioxide is introduced into the carbon dioxide recovery device 30, part or all of the solidified carbon dioxide present in the carbon dioxide recovery device 30 is dissolved in liquid carbon dioxide, and part or all of the dissolved carbon dioxide is recovered with carbon dioxide It is discharged out of the device 30.

  In the first step, for example, the exhaust gas is cooled by flowing it through a cooling medium, and moisture, nitrogen oxides, and sulfur oxides contained in the exhaust gas are liquefied or solidified in the cooling medium and separated together with the medium. be able to. In this case, the separated harmful gas component contains a cooling medium, but in this system, the cooling medium is separated from the harmful gas component by an evaporation method using a vaporization temperature difference between the cooling medium and the harmful gas component. Then, the cooling medium is recovered, and the recovered cooling medium is reused again as a cooling medium, thereby effectively using the cooling medium.

  In this evaporation method, heating energy is required, but heating energy can be reduced by adopting a cooling medium having a low boiling point. In order to separate the cooling medium from the liquefied or solidified harmful gas component, the cooling medium needs to have a temperature range that does not solidify even at a temperature at which the harmful gas component is liquefied or solidified. Further, the cooling medium needs to have a property of easily absorbing the harmful gas component so that the harmful gas component can be efficiently separated. Furthermore, the cooling medium needs to have a property that carbon dioxide is hardly dissolved so that carbon dioxide contained in the exhaust gas can be efficiently removed in the second step.

  Examples of substances that satisfy these requirements include dimethyl ether (hereinafter referred to as DME), inorganic salts (sodium chloride, potassium chloride, etc.), bromine compounds (lithium bromide, bromide bromide, etc.), ethers (dimethyl ether, methyl ether). Etc.), alcohols (methanol, ethanol, etc.), silicon oils, paraffinic hydrocarbons (propane, normal butane, etc.), olefinic hydrocarbons, toluene, ethylbenzene, and the like. In order to separate the liquefied or solidified harmful gas component from the cooling medium, it is advantageous that the difference in boiling point between the cooling medium and the harmful gas component is large. From such a point of view, ethers and alcohols are suitable as the cooling medium. For example, when dimethyl ether is used, dimethyl ether is vaporized by heating to (−24.9 ° C. or higher), and harmful gas. Ingredients remain liquid or solid.

  In this first step, the exhaust gas temperature may be controlled by bringing the exhaust gas into contact with a refrigerant pipe or the like through the cooling medium instead of circulating the exhaust gas through the cooling medium as shown here.

  A specific treatment process of this exhaust gas treatment system using the above system will be described in order. First, as pretreatment, exhaust gas containing harmful gas components such as nitrogen oxides and sulfur oxides discharged from exhaust gas generation sources 10 such as coal fired boilers, heavy oil fired boilers, blast furnaces, coke ovens, converters, etc. in steelworks. And introduced into the heat exchanger 11. Seawater (for example, 25 ° C.) supplied by the seawater pump 12 and refrigerant such as ethylene glycol circulated and supplied from the refrigerator 40 are guided to the heat exchanger 11. Exhaust gas (for example, 55 ° C.) guided from the exhaust gas generation source 10 is cooled to about room temperature by the seawater and the refrigerant by passing through the heat exchanger 11.

The exhaust gas cooled to about room temperature in the heat exchanger is then led to a condenser (condenser) 13. In the condenser 13, the exhaust gas is introduced into industrial water accommodated in the condenser 13. As a result, moisture, water-soluble harmful gas components (for example, part of SO ₂ , NO ₂ ), dust, and the like contained in the exhaust gas are removed. The liquefied water containing moisture, harmful gas components, dust, etc. removed from the exhaust gas is once stored in the drainage tank 14 and then guided to the wastewater treatment device 50 by the drainage pump 15.

  On the other hand, the exhaust gas that has passed through the condenser 13 is guided to the dehydration tower 17 by the exhaust gas fan 16. The dehydration tower 17 includes a cooling device (corresponding to the first cooling device), a fourth inlet, a fourth outlet, and a fifth outlet. In the dehydration tower 17, the exhaust gas is further dehydrated (dehumidified) and harmful gas components (such as nitrogen oxides and sulfur oxides) are removed. Here, by dehydrating the moisture in the exhaust gas, carbon dioxide can be efficiently recovered in a subsequent carbon dioxide recovery step in the exhaust gas.

  In the dehydration tower 17, the exhaust gas is introduced from the lower side (fourth inlet) of the dehydration tower 17. The exhaust gas introduced into the dehydration tower 17 is distributed to the DME filled in the dehydration tower 17 by a bubbling method. The exhaust gas is cooled by exchanging heat with DME. The cooling temperature at this time is a temperature at which harmful gas components such as moisture, nitrogen oxides, and sulfur oxides in exhaust gas are liquefied or solidified, but carbon dioxide is not solidified, and is, for example, −90 ° C. . By cooling the exhaust gas to such a temperature, harmful gas components are liquefied or solidified and separated from the exhaust gas, but carbon dioxide remains in the exhaust gas as a gas.

Here, in order to confirm the function of removing harmful gas components from the exhaust gas in the dehydration tower 17, the amount of sulfur dioxide (SO ₂ ) and nitrogen monoxide (NO) dissolved in the cooling medium was measured. FIG. 3A shows the configuration of the apparatus used for this measurement. The apparatus 210 includes a mixer 211 that generates simulated exhaust gas, a cooling container 212 (in this case, a glass container is used) for cooling the simulated exhaust gas that is regarded as the dehydration tower 17, and a gas that introduces the simulated exhaust gas into the cooling container 212. A gas discharge pipe 214 for discharging the gas accumulated above the introduction pipe 213 and the cooling container 212 to the outside of the cooling container 212 is connected as shown in FIG.

Toluene (5 ° C., liquid amount 100 cc) was used as a cooling medium in the cooling vessel 212. The opening of the gas introduction pipe is set so as to be located below the toluene liquid level. As the simulated gas carbon dioxide _(CO 2), sulfur dioxide _(SO 2), nitrogen monoxide (NO), was a mixture by a mixer nitrogen _{(N 2).} FIG. 3B shows the composition of the simulated exhaust gas. The concentration of sulfur dioxide (SO ₂ ) and nitrogen monoxide (NO) in the gas discharged from the gas discharge pipe 214 was measured by circulating simulated exhaust gas through toluene at a constant rate (1 l / h).

In FIG. 3C, the measurement results are shown together with a graph showing the relationship between the temperature of the cooling medium (toluene) and the dissolved amount (ppm) (saturated dissolved amount) of sulfur dioxide (SO ₂ ) and nitric oxide (NO). . The two curves in the figure show the amount of sulfur dioxide (SO ₂ ) dissolved (ppm) and the amount of nitric oxide (NO) dissolved (ppm) calculated by the SRK (Soave-Redlich-Kwong) method, respectively. The calculated theoretical values were plotted. The conditions were normal pressure, temperature -90 ° C to 30 ° C, and the target substance toluene.

In addition, the mark “◯” plotted in the graph is an actual measurement value obtained by the above measurement, the dissolution amount with respect to sulfur dioxide (SO ₂ ) is 48 (ppm), and the dissolution amount with respect to nitric oxide (NO). The amount was 0.1 (ppm). The theoretical value of the dissolved amount of sulfur dioxide (SO ₂ ) at 5 ° C. was 36 (ppm), and the actually measured value of the dissolved amount of nitric oxide (NO) was 0.07 (ppm), which was measured using this apparatus. In this case, it was confirmed that the saturated dissolution amount of sulfur dioxide (SO2) and nitric oxide (NO) coincided with the values theoretically obtained by the SRK method. Therefore, it was shown that the function of removing harmful gas components from the exhaust gas in the dehydration tower 17 is operating normally. Further, it was verified that the dehydration tower 17 can efficiently separate harmful gas components from the exhaust gas.

  The DME in which the exhaust gas is circulated in the dehydration tower 17 is discharged from the fifth outlet and is guided to the DME separation tower 20. The DME guided to the DME separation tower 20 contains liquefied or solidified moisture and harmful gas components. Here, DME raises temperature by indirectly exchanging heat with seawater (for example, −20 ° C.). At this temperature, the moisture and harmful gas components are liquid or solid, and DME becomes a gas (corresponding to the third step). For this reason, DME floats above the DME separation tower 20 and is separated from other components. The floated DME is recovered from above the DME separation tower 20 and guided to the DME cooling tower 18. Refrigerant (liquid nitrogen) cooled by the refrigerator 40 is circulated to the DME cooling tower 18 by a circulation pump 19, and the DME supplied from the DME separation tower 20 is cooled in the DME cooling tower 18. Liquefy DME. The regenerated DME is guided again to the dehydration tower 17 (corresponding to the fourth step). The DME is circulated and reused in this way, so that the cooling medium is efficiently utilized as a whole system.

  Next, moisture (liquid or solid) and harmful gas components remaining in the DME separation tower 20 are guided to the component separation tower 22 by the transport pump 21. Here, the moisture and harmful gas components are indirectly heat-exchanged with seawater to increase the temperature (for example, 5 ° C.). At this temperature, moisture and nitrogen dioxide are liquids, and sulfur dioxide is a gas (corresponding to the fifth step). The sulfur dioxide that has been heated to become gas is discharged from above the component separation tower 22 and then led to the heat exchanger 11 to cool the exhaust gas (for example, 55 ° C.) guided from the exhaust gas generation source 10. It is used as a refrigerant. By using sulfur dioxide as a refrigerant in this way, the energy consumption of the entire system can be suppressed.

  This sulfur dioxide is heated to 45 ° C., for example, as a refrigerant in the heat exchanger 11, and thereafter led to the chimney 51 and discharged out of the system. In addition, harmful gas components such as liquefied water and nitrogen dioxide other than sulfur dioxide remaining in the component separation tower 22 are guided to the waste water treatment device 50.

  The exhaust gas containing carbon dioxide that floats above the dehydration tower 17 is discharged from the fourth outlet and guided to the reversible heat exchanger 23. The exhaust gas led from the dehydration tower 17 to the reversible heat exchanger 23 is cooled here and then led to the carbon dioxide recovery device 30.

  The carbon dioxide recovery device 30 is a device that solidifies carbon dioxide contained in the exhaust gas using a cooling device. The exhaust gas led to the carbon dioxide recovery device 30 is cooled by indirectly exchanging heat with a refrigerant (for example, liquid nitrogen) circulated through the refrigerator 40 in the carbon dioxide recovery device 30. Thereafter, liquid carbon dioxide stored in the carbon dioxide storage tank 121 is introduced into the carbon dioxide recovery device 30, and the solidified carbon dioxide existing in the carbon dioxide recovery device 30 is dissolved in the liquid carbon dioxide. The detailed configuration and function of the carbon dioxide recovery device 30 will be described later.

  The liquefied carbon dioxide is sent to the carbon dioxide storage tank 121 and stored. On the other hand, the exhaust gas from which carbon dioxide has been removed in the carbon dioxide recovery device 30 is introduced into the reversible heat exchanger 23 and used as a refrigerant, and is then guided to the heat exchanger 11. The exhaust gas is used again as a refrigerant in the heat exchanger 11 and then released from the chimney 51 to the outside of the system. Here, carbon dioxide has already been removed from the exhaust gas released into the atmosphere, and the concentration of carbon dioxide contained in the gas is very low.

  By the way, the refrigerator 40 described above includes a turbine-type compressor 41 (nitrogen booster), a circulating nitrogen compressor 42, a condenser 43 that expands a refrigerant to obtain a low temperature, liquid nitrogen that is a refrigerant, ethylene glycol, and another system. A heat exchanger 44 that exchanges heat with the liquid nitrogen circulated in is provided, and nitrogen gas as a refrigerant is cooled. The refrigerator 40 cools the nitrogen gas by repeatedly compressing and expanding with energy such as electric energy. The liquid nitrogen produced by cooling is a liquid circulated in a separate system from the cooling of ethylene glycol circulated to the heat exchanger 11, the liquid nitrogen circulated to the DME cooling tower 18, the carbon dioxide recovery device 30, and the like. Used for cooling refrigerants such as nitrogen.

  As described above, in the exhaust gas treatment system of the present embodiment, coal-fired boilers, heavy oil-fired boilers, nitrogen oxides and sulfur oxides discharged from blast furnaces, coke ovens, converters, etc. in steelworks As for the exhaust gas containing noxious gas components, moisture and noxious gas components contained in the exhaust gas can be efficiently removed. Moreover, carbon dioxide contained in the exhaust gas can be efficiently recovered while efficiently removing moisture and harmful gas components.

In the above description, examples of harmful gases to be removed from exhaust gas include other nitrogen oxides (NO _X ) such as carbon monoxide and nitrogen monoxide, and other sulfur oxides such as sulfur monoxide. (SO _x ), halogen compounds such as hydrogen fluoride, etc., by appropriately setting the solidification temperature of carbon dioxide and the liquefaction or solidification temperature of harmful gas components, and selecting an appropriate cooling medium as described above, These harmful gas components can be efficiently removed. That is, the exhaust gas containing other types of harmful gases is circulated through the cooling medium and cooled to the first temperature, whereby the harmful gases contained in the exhaust gas are liquefied or solidified to be separated from the exhaust gas, and the exhaust gas is separated from the exhaust gas. By cooling to a second temperature lower than the temperature of 1, an exhaust gas treatment system having a configuration in which carbon dioxide contained in the exhaust gas is solidified and separated from the exhaust gas can be realized.

= Second Embodiment =
In the exhaust gas treatment system according to the present invention, a solid-liquid separation device 28 may be provided after the dehydration tower 17. The DME that has contained the liquefied or solidified moisture and harmful gas components due to the circulation of the exhaust gas in the dehydration tower 17 is in a sherbet state (slurry). , The solidified product contained in the DME is separated. The DME after being separated by the solid-liquid separation device 28 is led to the DME separation tower 20 for reuse. This solid-liquid separation device 28 can be suitably used when solidified substances (for example, moisture, NO ₂ ) are included in the exhaust gas to be treated, such as exhaust gas generated from an LNG-fired boiler or the like.

  In addition, regarding exhaust gas that does not contain sulfur oxides, such as exhaust gas generated from an LNG-fired boiler, it is not necessary to provide the component separation tower 22 after the DME separation tower 20 separates DME.

  Therefore, as a typical example having these partial changes, a schematic configuration of an exhaust gas treatment system for exhaust gas generated from an LNG-fired boiler or the like is shown in FIG. 4 as a second embodiment of the present invention.

  In the present embodiment, the refrigeration / heat exchanger 44 uses the heat of LNG vaporization to circulate ethylene glycol circulated to the heat exchanger 11, liquid circulated to the DME cooling tower 18, the carbon dioxide recovery device 30, etc. A refrigerant such as nitrogen can be cooled. For example, in a power plant using LNG as gas fuel, LNG is transported in a liquid state of, for example, −150 ° C. to −165 ° C. and stored in the LNG tank 61 or the like. Here, when LNG is used as a gas fuel, the heat of vaporization is obtained from the atmosphere or seawater and the temperature is raised to vaporize. The refrigeration / heat exchanger 44 uses the heat of vaporization at this time to generate ethylene glycol or A refrigerant such as liquid nitrogen may be cooled. That is, the exhaust gas or the cooling medium is cooled by using the heat of vaporization generated when LNG is used as the gas fuel. A technique for solidifying and separating carbon dioxide contained in the exhaust gas by using the heat of vaporization of LNG is described in, for example, Japanese Patent Application Laid-Open No. 8-12314.

<CO2 recovery system>
= First embodiment =
FIG. 5 is a schematic configuration diagram of a carbon dioxide recovery system 70 described as an embodiment of the present invention.

  The carbon dioxide recovery system 70 of this embodiment includes a carbon dioxide recovery device 30 and a carbon dioxide storage tank 121. Here, the carbon dioxide recovery device 30 includes a container 103 and a cooling device 109, and includes a first inlet 106, a first outlet 107, a second inlet 111, a second outlet 112, and a second inlet. A control valve 125 for supplying more liquid carbon dioxide and a control valve 126 for discharging the solidified carbon dioxide dissolved from the second outlet are provided.

  The container 103 has two first cylindrical tubes 104 arranged vertically, and is disposed horizontally below the first cylindrical tubes 104 (that is, perpendicular to the first cylindrical tube 104). A second cylindrical tube 105 is provided that communicates with the interior of each of the first cylindrical tubes 104. Here, examples of the material of the cylindrical tube include SUS304. A first inlet 106 for supplying a gas containing carbon dioxide is provided at a predetermined position on the upper surface of one of the first cylindrical tubes 104. In addition, a first outlet 107 is provided at a predetermined position on the upper surface of the other first cylindrical tube 104 to discharge the gas after removing part or all of carbon dioxide to the outside of the container 103. Note that a differential pressure gauge 124 may be provided in order to check whether an appropriate amount of gas existing in the container 103 is discharged from the first outlet.

  In the present embodiment, two first cylindrical tubes 104 are used, but this number is not particularly limited, and three or more may be used.

  In the present embodiment, the container 103 has a shape including two cylindrical tubes, but may have a rectangular parallelepiped shape. When a rectangular parallelepiped container is used, the position where the first outlet 107 is separated from the first inlet 106 by a predetermined distance so that the gas supplied from the first inlet 106 stays in the container 103 for a predetermined time or longer. It is preferable to provide in.

  The piping connected to the first inlet 106 is provided with a control valve 113 as an example of means for controlling the gas supply amount. The pipe connected to the first outlet 107 is provided with a control valve 114 as an example of means for controlling the gas discharge amount. The pipe connected to the second inlet 111 is provided with a control valve 125 as an example of means for adjusting the supply of liquid carbon dioxide stored in the carbon dioxide storage tank 121, and connected to the second outlet 112. The piping to be provided is provided with a control valve 126 as an example of means for adjusting the discharge of carbon dioxide dissolved by the supplied liquid carbon dioxide.

  When the control valve 125 is opened, liquid carbon dioxide is supplied to the container 103, and the dry ice present in the container 103 is dissolved. The dissolved carbon dioxide is discharged out of the container 103 when the control valve 126 is opened, and stored in the carbon dioxide storage tank 121.

  By closing all the control valves 113, 114, 125, and 126, the inside of the container 103 is completely sealed.

  The carbon dioxide storage tank 121 communicates with the inside of the second cylindrical tube 105. In order to heat the carbon dioxide in the carbon dioxide storage tank 121, a heat transfer tube (heat transfer device) 122 may be embedded in the wall surface of the carbon dioxide storage tank 121, or an electric heater (for example, a silicon rubber heater, A fluororesin heater may be provided. When the heat transfer tube (heat transfer device) 122 is used, it is preferable to provide a control valve as an example of means for controlling the flow rate of the heat medium flowing through the heat transfer tube 122 upstream of the heat transfer tube 122. The heat medium is preferably a dry gas, for example, and the heat medium is transported from the heat source 123 to the heat transfer tube 122. The heat transfer tube 122 may be provided inside the carbon dioxide storage tank 121 instead of being embedded in the wall surface of the carbon dioxide storage tank 121.

  In order to cool the container 103, a cooling device 109 is provided in the container 103. In this embodiment, the cooling device 109 is provided outside the container 103. Specifically, as shown in FIG. 5, a cooling device configured to cover the entire container 103 may be used, or a cooling device configured to cool the container 103 from the outside by winding a refrigerant circulation pipe or the like around the container 103. The form of the cooling device 109 is not particularly limited. The refrigerant that can be used in the cooling device is preferably a refrigerant that can be cooled to a temperature equal to or lower than the temperature at which carbon dioxide is solidified, and examples thereof include liquid nitrogen. In addition, when using liquid nitrogen as a refrigerant | coolant, the liquid nitrogen used as a refrigerant | coolant is supplied from the refrigerator 40. FIG.

  In order to increase the contact area of the dry ice to the inner surface of the container 103 in order to deposit more carbon dioxide on the inner surface of the container 103 when the carbon dioxide solidifies in the container 103, screw-like fins are provided on the inner surface of the container 103. It may be formed.

  If dry ice is attached to the inner surface of the container 103, the area on which the carbon dioxide can adhere to the inner surface of the cooled container 103 is reduced, so that the amount of dry ice recovered is reduced and the amount of gas in the container 103 is reduced. Since the passage is blocked, the amount of gas passing is reduced. In order to solve this problem, liquid carbon dioxide stored in the carbon dioxide storage tank 121 is introduced into the container 103, and part or all of the dry ice present in the container 103 is dissolved in liquid carbon dioxide, and the dissolved dry carbon Ice is discharged out of the container 103. In order to efficiently solidify carbon dioxide in the container 103, a sensor for measuring the temperature of the gas in the container 103, a sensor for measuring the temperature of the surface of the cooling device 109, and a sensor for measuring the pressure in the container 103. Various sensors such as these may be provided in the container 103. The output value of each sensor may be controlled by a measuring device or a computer. Further, a small window may be provided at a predetermined position of the container 103, and it may be confirmed visually whether dry ice is produced.

= Second Embodiment =
In the present embodiment, a cooling device 109 for cooling the container 103 is provided inside the container 103. For example, as shown in FIG. 6, the refrigerant flow pipe 217 is inserted into the first cylindrical pipe 104. Specifically, for example, the length may be 900 mm × 20, the outer surface area of the pipe 7.1 m ² , and the material: a copper pipe (with fins). The refrigerant circulation pipe to be inserted may be branched into two inside the container 103 in order to ensure a sufficient contact area with the gas circulated inside the container 103. In addition, the meandering area inside the first cylindrical tube 104 may be sufficient to ensure a sufficient contact area with the gas. Liquid nitrogen serving as a refrigerant is supplied from an inlet 218 provided at a predetermined position on the upper surface of the first cylindrical tube 104 and discharged from an outlet 219. A control valve 220 is provided upstream of the refrigerant flow pipe 217 as an example of means for controlling the flow rate of the refrigerant.

  Since the gas supplied into the container 103 is cooled by the above method to a temperature at which carbon dioxide is solidified, the carbon dioxide contained in the gas is solidified in the container 103 and is a refrigerant circulation pipe inside the container 103. It adheres to the outer surface of 217. In order to peel this dry ice from the adhering surface, the container 103 may be provided with a vibration device.

<CO2 recovery method>
Hereinafter, a method for recovering dissolved dry ice using any one of the carbon dioxide recovery systems will be described. In the initial state, it is assumed that the control valves 113, 114, 125, and 126 are all closed.

  First, the cooling device 109 is activated to start cooling the inside of the container 103. At this time, the temperature of the inner surface of the container 103 is lowered to a temperature at which carbon dioxide is solidified. That is, as shown in FIG. 7, since the sublimation point of carbon dioxide is −78.5 ° C. at 1 atm, when the pressure in the container 103 is 1 atm, the temperature of the inner surface of the container 103 is at least −78.5 ° C. or lower.

  After the temperature of the inner surface of the container 103 reaches the above temperature, the control valve 113 and the control valve 114 are opened, a gas containing carbon dioxide is supplied from the control valve 113, and supply of the gas to the container 103 is started. Here, the gas flowing through the container 103 is cooled by the cooling device 109 in the container 103, and carbon dioxide contained in the gas is deposited as dry ice on the inner surface of the container 103. The gas from which carbon dioxide has been removed moves through the container 103 and is discharged from the control valve 114 to the outside of the container 103.

  Next, a heat medium is circulated through the heat transfer tube 122, the temperature and pressure in the carbon dioxide storage tank 121 are increased, and the carbon dioxide existing in the carbon dioxide storage tank 121 is liquefied.

  Next, the control valves 113 and 114 are closed to seal the container 103, and the carbon dioxide can be in a liquid state by using a pressure applying means for increasing the pressure inside the container 103, such as a pressure pump. The inside of the container 103 is pressurized beyond the pressure. At this time, as shown in FIG. 7, since the triple point of carbon dioxide is 5.11 atm / -56.6 ° C., the pressure in the container 103 rises to 5.11 atm or more in order to liquefy the dry ice in the container 103. It must be allowed. Further, since the dry ice in the container 103 is liquefied using liquid carbon dioxide stored in the carbon dioxide storage tank 121, the pressure in the container 103 is preferably the same as the pressure in the carbon dioxide storage tank 121. . Thus, since the pressure in the container 103 must be increased, the material of the container 103 is preferably pressure resistant.

  Next, the liquid carbon dioxide in the carbon dioxide storage tank 121 is supplied to the container 103 from the second inlet 111 of the container 103, and the dry ice in the container 103 is liquefied.

  Finally, the liquid carbon dioxide existing in the container 103 is discharged from the second outlet 112 of the container 103, supplied to the carbon dioxide storage tank 121, and the liquid carbon dioxide is stored in the carbon dioxide storage tank 121. This liquid carbon dioxide may be supplied again to the second inlet 111 of the container 103 in order to liquefy the dry ice in the container 103.

  Here, as a condition for supplying liquid carbon dioxide to the second inlet 111 of the container 103, for example, a differential pressure gauge 124 is provided at the inlet 106 and the outlet 107 of the container 103, and the pressure between the inlet 106 and the outlet 107 of the container 103 is set. This is the case when the difference between the values exceeds a certain level.

  In addition, for example, the control valves 113, 114, 125, and 126 are electromagnetic valves, and a control line for controlling each electromagnetic valve is connected to a computer so that the computer hardware and control software that operates on the hardware are connected. The electromagnetic valve may be remotely controlled by wear. Moreover, you may make it perform all or one part of the process mentioned above automatically based on the output value of the said various sensors.

  As described above, according to the carbon dioxide recovery system 70 of the present embodiment, the dry ice attached to the inner surface of the container 103 can be efficiently recovered by dissolving it in liquid carbon dioxide. Furthermore, since the carbon dioxide recovery system 70 of this embodiment makes liquid carbon dioxide contact the dry ice which exists in the container 103 directly, it can peel off the attached dry ice efficiently.

  As mentioned above, although several embodiment was described, description of these embodiment is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

It is a figure explaining one of the techniques which isolate | separate a carbon dioxide. In one Embodiment of this invention, it is a figure which shows schematic structure of an waste gas processing system. In one Embodiment of this invention, it is a figure which shows the structure of the apparatus used for the measurement of the melt | dissolution amount to the cooling medium about sulfur dioxide, nitric oxide, etc. FIG. In one Embodiment of this invention, it is a figure which shows the composition of simulation exhaust gas. In one Embodiment of this invention, it is a figure which shows the measurement result of the melt | dissolution amount to the cooling medium about sulfur dioxide and nitric oxide. In one Embodiment of this invention, it is a figure which shows schematic structure of an waste gas processing system. In one Embodiment of this invention, it is a figure which shows schematic structure of a gas processing system. In one Embodiment of this invention, it is a figure which shows schematic structure of a gas processing system. In one Embodiment of this invention, it is a figure which shows the TP (temperature-pressure) diagram of a carbon dioxide.

Explanation of symbols

10 Exhaust gas generation source / 11 Heat exchanger / 12 Seawater pump / 13 Condenser (condenser) / 14 Drainage tank / 15 Drainage pump / 16 Exhaust gas fan / 17 Dehydration tower / 18 DME cooling tower / 19 Circulation pump / 20 DME separation tower / 21 Transport pump / 22 Component separation tower / 23 Reversible heat exchanger / 28 Solid-liquid separation device / 30 Carbon dioxide recovery device 40 Refrigerator / 41 Nitrogen booster / 42 Circulating nitrogen compressor / 43 Condenser / 44 Heat exchanger / 50 Wastewater treatment device / 51 Chimney / 61 LNG tank / 70 Carbon dioxide recovery system / 103 Container / 104 First cylindrical tube / 105 Second cylindrical tube / 106 First inlet / 107 First outlet / 109 Cooling Device / 111 Second inlet / 112 Second outlet / 113 Control valve / 114 Control valve / 121 Carbon dioxide storage tank / 122 Transmission Pipe / 123 Heat source / 124 Differential pressure gauge / 125 Control valve / 126 Control valve / 210 Device / 211 Mixer / 212 Cooling vessel / 213 Gas introduction pipe / 214 Gas discharge pipe / 217 Refrigerant flow pipe / 218 Liquid nitrogen inlet / 219 Liquid Nitrogen outlet / 220 Control valve / 1100 Refrigerant / 1101 Container / 1102 Heat transfer tube / 1103 Gas / 1104 Collection container / 1105 Dry ice / 1106 Dry ice liquefier / 1107 Liquid carbon dioxide

Claims (38)

By cooling the gas containing carbon dioxide at a temperature at which the carbon dioxide is solidified, the carbon dioxide contained in the gas is solidified and adhered to the inner surface of the container into which the gas is introduced,
Sealing the container,
Pressurizing the inside of the container above the pressure at which carbon dioxide can take a liquid state,
Introducing liquid carbon dioxide into the container;
Dissolving part or all of the solidified carbon dioxide present in the container in the liquid carbon dioxide;
Discharging part or all of the dissolved carbon dioxide out of the container;
Recovering the dissolved dissolved carbon dioxide,
A gas treatment method characterized by the above. The gas further containing one of nitrogen oxide or sulfur oxide is contained in the gas by cooling to a first temperature that does not solidify carbon dioxide but liquefy or solidify the nitrogen oxide or sulfur oxide. A first step of liquefying or solidifying nitrogen oxide or sulfur oxide from the gas;
By cooling the gas from which the nitrogen oxides or sulfur oxides have been removed to a second temperature at which carbon dioxide is solidified, the carbon dioxide contained in the gases from which the nitrogen oxides or sulfur oxides have been removed is solidified, It is attached to the inner surface of the container to which the gas from which the nitrogen oxide or sulfur oxide has been removed is supplied, and the container is sealed, and the interior of the container is added above the pressure at which carbon dioxide can take a liquid state. Pressure, liquid carbon dioxide is introduced into the container, part or all of the solidified carbon dioxide present in the container is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is dissolved in the container. A second step of discharging outside,
The gas processing method according to claim 1, comprising:   In the first step, the nitrogen oxide or sulfur oxide contained in the gas is circulated by passing the gas through a cooling medium having a temperature equal to or lower than the temperature at which the nitrogen oxide or sulfur oxide is liquefied or solidified. The gas processing method according to claim 2, wherein the gas is removed from the gas.   The cooling medium containing the nitrogen oxide or sulfur oxide separated from the gas in the first step is heated to a temperature at which the cooling medium is vaporized but the nitrogen oxide or sulfur oxide is not vaporized. The gas processing method according to claim 3, further comprising a third step of separating the nitrogen oxide or sulfur oxide and the cooling medium. Including a fourth step of reusing the cooling medium separated from the nitrogen oxides or sulfur oxides as the cooling medium for circulating the gas;
The gas processing method according to claim 4, wherein: Nitrogen oxidation contained in the gas by cooling the gas further containing nitrogen oxide and sulfur oxide to a first temperature that does not solidify carbon dioxide but liquefy or solidify the nitrogen oxide and sulfur oxide. A first step of liquefying or solidifying the product and sulfur oxide from the gas;
By cooling the gas from which the nitrogen oxides and sulfur oxides have been removed to a second temperature at which carbon dioxide is solidified, the carbon dioxide contained in the gases from which the nitrogen oxides and sulfur oxides have been removed is solidified, It is attached to the inner surface of the container supplied with the gas from which the nitrogen oxide and sulfur oxide have been removed, and the container is sealed, and the interior of the container is added to a pressure higher than that at which carbon dioxide can take a liquid state. Pressure, liquid carbon dioxide is introduced into the container, part or all of the solidified carbon dioxide present in the container is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is dissolved in the container. A second step of discharging outside,
The gas processing method according to claim 1, comprising:   In the first step, by passing the gas through a cooling medium having a temperature equal to or lower than the temperature at which the nitrogen oxide and sulfur oxide are liquefied or solidified, the nitrogen oxide and sulfur oxide contained in the gas are reduced. It removes from the said gas, The gas processing method of Claim 6 characterized by the above-mentioned.   The cooling medium containing the nitrogen oxides and sulfur oxides separated from the gas in the first step is heated to a temperature at which the cooling medium is vaporized but the nitrogen oxides and sulfur oxides are not vaporized. The gas processing method according to claim 6, further comprising a third step of separating the nitrogen oxide and sulfur oxide from the cooling medium. Including a fourth step of reusing the cooling medium separated from the nitrogen oxides and sulfur oxides as the cooling medium for circulating the gas;
The gas processing method according to claim 8, wherein:   The nitrogen oxides and sulfur oxides separated from the gas in the first step are heated to a temperature at which sulfur oxides are vaporized but nitrogen oxides are not vaporized. The gas processing method according to claim 6, further comprising a fifth step of separating the first and second steps.   The gas treatment method according to claim 3, wherein the cooling medium includes any one of dimethyl ether, methanol, ethanol, toluene, and ethylbenzene. The container has a refrigerant circulation device that circulates a refrigerant having a temperature equal to or lower than a temperature at which carbon dioxide is solidified;
Cooling the gas by bringing the gas into contact with the outside of the refrigerant distribution device;
The gas processing method according to claim 1, wherein:   The gas processing method according to claim 12, wherein the refrigerant distribution device is tubular and is provided meandering in the container.   The gas processing method according to claim 1, wherein the first step includes a step of separating moisture contained in the gas from the gas.   The gas processing method according to claim 1, wherein the gas is exhaust gas discharged from an LNG-fired boiler. The liquid carbon dioxide is supplied from the carbon dioxide storage tank to the container,
The discharged dissolved carbon dioxide is collected into the carbon dioxide storage tank;
The gas processing method according to claim 1, wherein:   The gas processing method according to claim 16, wherein the pressure in the carbon dioxide storage tank is the same as the pressure in the container.   The gas processing method according to claim 1, wherein the pressure is 5.11 atm or more. The gas containing carbon dioxide is cooled at a temperature at which carbon dioxide is solidified, so that the carbon dioxide contained in the gas is solidified and adhered to the inner surface of the container into which the gas has been introduced. Sealing, pressurizing the inside of the container to a pressure higher than the pressure at which carbon dioxide can take a liquid state, introducing liquid carbon dioxide into the container, and part or all of the solidified carbon dioxide present in the container Dissolving in liquid carbon dioxide and discharging part or all of the dissolved carbon dioxide out of the container;
A gas processing apparatus characterized by the above. A gas treatment device for removing carbon dioxide from a gas containing carbon dioxide,
A first inlet for supplying the gas containing carbon dioxide; a first outlet for discharging the gas after removing part or all of the carbon dioxide; and for supplying liquid carbon dioxide. A container having a second inlet and a second outlet for discharging solid carbon dioxide dissolved by the liquid carbon dioxide;
A cooling device for solidifying the carbon dioxide;
With
The container is
Means for controlling the amount of the gas supplied from the first inlet;
Means for controlling the amount of gas discharged from the first outlet;
Supply means for supplying the liquid carbon dioxide from the second inlet;
Discharging means for discharging the solidified carbon dioxide dissolved from the second outlet;
A recovery means for recovering the dissolved carbon dioxide discharged from the second outlet;
Pressure applying means for applying pressure in the container;
A gas treatment device comprising:   21. The gas processing device according to claim 20, wherein the cooling device is a refrigerant distribution device for distributing a refrigerant having a temperature equal to or lower than a temperature at which carbon dioxide is solidified.   The gas processing apparatus according to claim 21, wherein the refrigerant circulation device is tubular and is provided in a meandering manner inside the container. By cooling the gas containing carbon dioxide and one of nitrogen oxides or sulfur oxides to a first temperature that does not solidify carbon dioxide but liquifies or solidifies the nitrogen oxides or sulfur oxides, the gas A first apparatus for liquefying or solidifying nitrogen oxides or sulfur oxides contained in the gas and removing them from the gas;
The gas from which the nitrogen oxides or sulfur oxides have been removed is cooled at a second temperature at which carbon dioxide is solidified to solidify the carbon dioxide contained in the gas from which the nitrogen oxides or sulfur oxides have been removed, It is attached to the inner surface of the container into which the gas from which the nitrogen oxides or sulfur oxides have been removed is introduced, and the container is sealed, and the interior of the container is added to a pressure higher than that at which carbon dioxide can take a liquid state. Pressure, liquid carbon dioxide is introduced into the container, part or all of the solidified carbon dioxide present in the container is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is dissolved in the container. A second device for discharging outside;
A gas processing system comprising: A gas treatment system for removing carbon dioxide and nitrogen oxides or sulfur oxides from a gas containing carbon dioxide and nitrogen oxides or sulfur oxides,
The gas processing system includes a first device and a second device,
The first device includes:
A third inlet for supplying the carbon dioxide and the gas containing nitrogen oxide or sulfur oxide, and exhausting the gas after removing part or all of the nitrogen oxide or sulfur oxide A first container with a third outlet for discharging and a fourth outlet for discharging the nitrogen oxides or sulfur oxides;
A first cooling device for liquefying or solidifying the nitrogen oxide or sulfur oxide;
With
The second device includes:
A first inlet for supplying the gas containing carbon dioxide discharged from the third outlet, and a first outlet for discharging the gas after removing part or all of the carbon dioxide A second inlet for supplying liquid carbon dioxide, a second outlet for discharging solid carbon dioxide dissolved by the liquid carbon dioxide, and a pressure applying means for applying pressure. A second container,
A second cooling device for solidifying the carbon dioxide;
With
The first container comprises:
Means for controlling the amount of the gas supplied from the third inlet;
Means for controlling the amount of gas discharged from the third outlet;
With
The second container is
Means for controlling the amount of the gas containing carbon dioxide supplied from the first inlet;
Means for controlling the amount of gas discharged from the first outlet;
Supply means for supplying the liquid carbon dioxide from the second inlet;
And a discharge means for discharging the solidified carbon dioxide dissolved from the second outlet.   The first cooling device causes the carbon dioxide and a gas containing nitrogen oxide or sulfur oxide to flow through a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxide or sulfur oxide is liquefied or solidified. The gas treatment system according to claim 24, wherein nitrogen oxides or sulfur oxides contained in the gas are removed from the gas.   The cooling medium containing nitrogen oxides or sulfur oxides separated from the gas by the first device is heated to a temperature at which the cooling medium is vaporized but the nitrogen oxides and sulfur oxides are not vaporized. The gas processing system according to claim 25, further comprising an apparatus that separates the nitrogen oxide or sulfur oxide from the cooling medium. A gas containing carbon dioxide, nitrogen oxides, and sulfur oxides is included in the gas by cooling to a first temperature that does not solidify carbon dioxide but liquefies or solidifies the nitrogen oxides and sulfur oxides. A first apparatus for liquefying or solidifying nitrogen oxides and sulfur oxides to be removed from the gas;
The gas from which the nitrogen oxides and sulfur oxides have been removed is cooled at a second temperature at which carbon dioxide is solidified to solidify the carbon dioxide contained in the gases from which the nitrogen oxides and sulfur oxides have been removed, The gas from which the nitrogen oxides and sulfur oxides have been removed is attached to the inner surface of the container to seal the container, and the interior of the container is added to a pressure higher than that at which carbon dioxide can take a liquid state. Pressure, liquid carbon dioxide is introduced into the container, part or all of the solidified carbon dioxide present in the container is dissolved in the liquid carbon dioxide, and part or all of the dissolved carbon dioxide is dissolved in the container. A second device for discharging outside;
A gas processing system comprising: A gas processing system for removing the carbon dioxide, nitrogen oxide, and sulfur oxide from a gas containing carbon dioxide, nitrogen oxide, and sulfur oxide,
The gas processing system includes a first device and a second device,
The first device includes:
A third inlet for supplying the gas containing carbon dioxide, nitrogen oxide, and sulfur oxide, and exhausting the gas after removing part or all of the nitrogen oxide and sulfur oxide A first container with a third outlet for discharging and a fourth outlet for discharging the nitrogen oxides and sulfur oxides;
A first cooling device for liquefying or solidifying the nitrogen oxides and sulfur oxides;
With
The second device includes:
A first inlet for supplying the gas containing carbon dioxide discharged from the third outlet, and a first outlet for discharging the gas after removing part or all of the carbon dioxide A second inlet for supplying liquid carbon dioxide, a second outlet for discharging solid carbon dioxide dissolved by the liquid carbon dioxide, and a pressure applying means for applying pressure. A second container,
A second cooling device for solidifying the carbon dioxide;
With
The first container comprises:
Means for controlling the amount of the gas supplied from the third inlet;
Means for controlling the amount of gas discharged from the third outlet;
With
The second container is
Means for controlling the amount of the gas containing carbon dioxide supplied from the first inlet;
Means for controlling the amount of gas discharged from the first outlet;
Supply means for supplying the liquid carbon dioxide from the second inlet;
Discharging means for discharging the solidified carbon dioxide dissolved from the second outlet;
A gas processing system comprising:   The first cooling device causes the gas containing carbon dioxide, nitrogen oxide, and sulfur oxide to flow through a cooling medium having a temperature equal to or lower than a temperature at which the nitrogen oxide and sulfur oxide are liquefied or solidified. The gas treatment system according to claim 28, wherein nitrogen oxides and sulfur oxides contained in the gas are removed from the gas.   The cooling medium containing nitrogen oxides and sulfur oxides separated from the gas by the first device is heated to a temperature at which the cooling medium is vaporized but the nitrogen oxides and sulfur oxides are not vaporized. 30. The gas processing system according to claim 29, further comprising an apparatus for separating the nitrogen oxide and sulfur oxide from the cooling medium. The gas contains nitrogen oxides and sulfur oxides;
The sulfur oxide and the nitrogen oxide are heated by raising the temperature to a temperature at which the sulfur oxide vaporizes the nitrogen oxide and sulfur oxide separated from the gas by the first device but does not vaporize the nitrogen oxide. 31. A gas treatment system according to any one of claims 27 to 30, characterized in that it comprises a separating device.   The gas processing system according to claim 26 or 30, further comprising a device that reuses the cooling medium separated from the gas as the cooling medium through which the gas flows.   The gas processing system according to any one of claims 25, 26, 29, 30 and 32, wherein the cooling medium includes any one of dimethyl ether, methanol, ethanol, toluene, and ethylbenzene.   The said 2nd cooling device is a refrigerant | coolant distribution | circulation apparatus for distribute | circulating the refrigerant | coolant of the temperature below the temperature which carbon dioxide solidifies, Any of Claims 24-26, 28-30, 32, or 33 characterized by the above-mentioned. A gas treatment system according to claim 1.   35. The gas processing system according to claim 34, wherein the refrigerant circulation device is tubular and is provided meandering in the second container. A recovery means for recovering the dissolved and solidified carbon dioxide discharged from the second outlet;
Providing the liquid carbon dioxide and comprising a carbon dioxide storage tank for storing the dissolved carbon dioxide;
The gas treatment system according to any one of claims 24 to 26, 28 to 30, or 32 to 35.   37. The gas processing system according to claim 36, further comprising adjusting means for adjusting the pressure of the carbon dioxide storage tank and the pressure in the dry ice recovery container to be the same. 38. The gas processing system according to claim 23, wherein the pressure is 5.11 atm or more.