Patent Publication Number: US-2023149852-A1

Title: Carbon dioxide recovery device

Description:
TECHNICAL FIELD 
     The present invention relates to a carbon dioxide recovery device provided with a separation device for separating carbon dioxide from to-be-separated gas including the carbon dioxide. 
     BACKGROUND ART 
     In recent years, climate change issues have become an imminent problem, and thus there has been demanded to develop a technique of separating and recovering carbon dioxide from gas such as combustion exhaust gas including carbon dioxide so that emission of carbon dioxide into the atmosphere is avoided. Further, a demand for carbon dioxide such as carbon dioxide gas used for welding and dry ice for distribution has been increasing. Under a circumstance of delay in supply in response to this increasing demand, there is a tendency of yearly increase in an import amount of carbon dioxide in our country. However, when carbon dioxide is to be imported in a form of dry ice, a part of it could melt during transportation, resulting in huge loss in the amount. In this situation, there has been a demand for a device that can recover or capture carbon dioxide with high purity by utilizing carbon dioxide included in combustion exhaust gas and the like emitted in a power plant. 
     As a device for recovering carbon dioxide with high purity from the exhaust gas and the like, there has been known a carbon dioxide recovery device including an absorption tower to absorb carbon dioxide in an absorption liquid and a regeneration tower to diffuse carbon dioxide with vapor from the absorption liquid that has absorbed carbon dioxide as disclosed in the Patent Document 1. 
     In the regeneration tower, the absorption liquid that has absorbed carbon dioxide is heated to a boiling temperature to perform diffusion of carbon dioxide and vapor. In order to suppress an amount of energy consumption for this heating, in the Patent Document 1, the regeneration tower is depressurized to lower the boiling temperature of the absorption liquid having absorbed the carbon dioxide for energy saving. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1; JP2005-270814A 
       
    
     SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
     However, the above conventional technique has the following problem. 
     The carbon dioxide recovery device disclosed in the Patent Document 1 uses a vacuum pump for depressurizing the regeneration tower. Operation of this vacuum pump requires a large amount of electric power, and thus there is a concern about increase in electric power cost and generation of further carbon dioxide for power generation. To address this, there has been a demand for a carbon dioxide recovery device which can achieve further energy saving in order to suppress increase in the electric power cost and generation of further carbon dioxide for power generation. 
     The present invention has been made to provide a carbon dioxide recovery device that can recover carbon dioxide while achieving further energy saving. 
     Means of Solving the Problems 
     To achieve the above purpose, a carbon dioxide recovery device according to one aspect of the present invention has the following configuration. 
     The carbon dioxide recovery device has the feature that the device comprising a separation device to separate carbon dioxide from to-be-separated gas including the carbon dioxide, wherein the separation device and a carbon dioxide sublimator to sublimate (solidify) the carbon dioxide having been separated by the separation device are connected in series in order from an upstream side of supplying the to-be-separated gas, the carbon dioxide sublimator is connected with a refrigerant circuit in which a fluid having cold heat is utilized as a refrigerant, and the carbon dioxide is sublimated (solidified) by the refrigerant, and when the carbon dioxide is sublimated (solidified), the carbon dioxide sublimator is depressurized to be under negative pressure so that the carbon dioxide having been separated by the separation device is sucked. 
     According to the above-mentioned carbon dioxide recovery device, the separation device of separating the carbon dioxide from the to-be-separated gas and emitting the separated carbon dioxide and the carbon dioxide sublimator of sublimating (solidifying) the carbon dioxide are connected in series. The carbon dioxide separated by the separation device is emitted from the separation device and then flows to the carbon dioxide sublimator. The carbon dioxide having reached the carbon dioxide sublimator is cooled down by the refrigerant, which utilizes the fluid having the cold heat, and is then sublimated (solidified). Dry ice generated by this sublimation (solidification) of the carbon dioxide is recovered by sublimation (gasification) again, and thus the carbon dioxide can be utilized as carbon dioxide gas or the like. 
     When the carbon dioxide is to be sublimated (solidified), the carbon dioxide sublimator is depressurized to be under the negative pressure. The carbon dioxide emitted from the separation device is sucked by this negative pressure. This suction causes flow of the carbon dioxide from the separation device to the carbon dioxide sublimator, so that sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimator is promoted. Suction of the carbon dioxide is performed by utilizing the fluid having the cold heat, and thus a pump or the like for suction is not necessary and energy conservation can be achieved. This energy conservation further achieves suppression in the increase in electric power cost and achieves suppression in the generation of further carbon dioxide for power generation. 
     As the fluid having the cold heat, there are provided for example, liquefied fuel and liquefied gas. The liquefied fuel is, for example, liquefied natural gas (LNG), liquid hydrogen, liquefied methane, and others. Natural gas as main material for city gas is imported in a form of LNG and then re-gasified in an LNG terminal and shipped by a gas pipeline. In regasification of the LNG, a large amount of cold heat energy is released, and this cold heat energy has attracted attention as unused energy. Accordingly, as mentioned above, utilizing the cold heat of the liquefied fuel for suction of the carbon dioxide results in good use of unused energy, so that a carbon dioxide recovery device can be made ecological. Herein, as the liquefied fuel, liquid hydrogen can be given other than the LNG. Further, the liquefied gas is, for example, exemplified as liquid nitrogen and liquid oxygen. Furthermore, the fluid having the cold heat is not necessarily in a form of liquid but may be gas, slurry, and gas-liquid multiphase flow. 
     Effects of the Invention 
     The carbon dioxide recovery device according to the present invention has the above-mentioned configuration, and thus can achieve recovery of carbon dioxide while saving energy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view showing a configuration of a carbon dioxide recovery device according to a first embodiment; 
         FIG.  2    is a schematic view showing a configuration of the carbon dioxide recovery device according to a second embodiment; 
         FIG.  3    is a schematic view showing a configuration of the carbon dioxide recovery device according to a third embodiment; 
         FIG.  4    is a schematic view showing a configuration of the carbon dioxide recovery device according to a modified example of the third embodiment; 
         FIG.  5    is a schematic view showing a configuration of the carbon dioxide recovery device according to a fourth embodiment; 
         FIG.  6    is a schematic view showing a configuration of the carbon dioxide recovery device according to a modified example of the fourth embodiment; 
         FIG.  7    is a graph showing a state of carbon dioxide; 
         FIG.  8    is a chart showing a mass ratio of recoverable liquefied carbon dioxide and a mass ratio of gasified carbon dioxide relative to a mass of dry ice for each of predetermined volume ratio; 
         FIG.  9    is a schematic view showing a configuration of the carbon dioxide recovery device according to a fifth embodiment; 
         FIG.  10    is a schematic view showing a configuration of the carbon dioxide recovery device according to a sixth embodiment: 
         FIG.  11    is a graph showing solubility of the carbon dioxide in amine solution according to the present embodiments; 
         FIG.  12    is a graph showing the solubility of the carbon dioxide in a conventional solution; 
         FIG.  13    is a view showing a configuration of a carbon dioxide sublimator, 
         FIG.  14    is another view showing the configuration of the carbon dioxide sublimator, and 
         FIG.  15    is a graph showing a range of partial pressure values of the carbon dioxide for each type of to-be-separated gas. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     First Embodiment 
     Firstly, a first embodiment of a carbon dioxide recovery device of the present invention is explained in detail with reference to the accompanying drawings. 
       FIG.  1    is a schematic view showing a configuration of a carbon dioxide recovery device  1 A according to the first embodiment. The carbon dioxide recovery device  1 A is provided with, as shown in  FIG.  1   , a separation device  60 , water vapor condensers  4 A,  4 B, and carbon dioxide sublimators  5 A,  5 B. 
     The separation device  60  is configured with an absorption tower  2  and a regeneration tower  3 . The absorption tower  2  is, for example, a countercurrent gas-liquid contact device and is filled inside with a filler  21  such as Raschig ring. 
     Further, the absorption tower  2  is provided with a gas introduction port  22  below the filler  21 , and to the gas introduction port  22 , a gas supply passage L 11  is connected. Combustion exhaust gas (one example of to-be-separated gas), which is for example generated in a power plant, an iron manufacturing plant, and a cement plant, is supplied from the gas supply passage L 11  to the absorption tower  2 . As the to-be-separated gas, the gas is not limited to the combustion exhaust gas but may be in the atmosphere. Other than that, biogas may be used, and off-gas including carbon dioxide generated from a heat treatment furnace such as a carburizing furnace and a chemical reaction device may be used. 
     The combustion exhaust gas includes carbon dioxide in its about 10 to 20% and also includes nitrogen, oxygen, and others. The combustion exhaust gas is considered to include sulfur oxide, and thus a desulfurization unit may be provided on the gas supply passage L 11  so that the combustion exhaust gas that has been removed with the sulfur oxide is supplied to the absorption tower  2 . 
     The absorption tower  2  is further provided with an absorption liquid introduction port  23  above the filler  21  to introduce the absorption liquid (lean liquid). As the absorption liquid, amino-based solvents and physical absorption liquid may be adapted. There are raised examples of amine as Monoethanolamine (MEA), Diethanolamine (DEA), Triethanolamine (TEA), Diethylethanolamine (DEEA), Diisopropylamine (DIPA), Aminoethoxyethanol (AEE), and Methyl diethanolamine (MDEA). There are raised examples of the physical absorption liquid as a derivative of chemical compound and Cycloetramethylene Sulfone (Sulfolane), aliphatic acid amide, NMP (N-Methyl-2-pyrrolidone), N-Alkylated 2-Pyrrolidone and corresponding Piperidone, and dialkyl-ether-group mixture of methanol and polyethylene glycol. 
     However, the most preferable one of the absorption liquid is amine solvent in which 2-(Ethylamino) ethanol and Diethylene Glycol Monoethyl Ether are mixed to have amine concentration of about 30% (hereinafter, referred as amine solvent according to the present embodiment). Application of the amine solvent according to the present embodiment achieves further efficient regeneration of the absorbed carbon dioxide as compared with conventionally known amine solvent (MEA solvent mixed to have about 30% of the amine concentration, which is hereinafter referred as a conventional solvent). 
       FIG.  11    is a graph showing a solubility of carbon dioxide in the amine solvent according to the present embodiment, and  FIG.  12    is a graph showing the solubility of the carbon dioxide according to the conventional liquid. Both graphs of  FIGS.  11  and  12    illustrate the solubility under the atmosphere of 40 degrees centigrade. 
     For example, when a pressure at the time of absorbing the carbon dioxide is set as 10 kPa and the pressure at the time of regenerating the absorbed carbon dioxide is set as 1 kPa, as shown in  FIG.  11    and  FIG.  12   , the amine solvent according to the present embodiment has a solubility gap D 11  of carbon dioxide between the time of absorbing and the time of regenerating as about 0.25 (mol-CO 2 /mol-amine), and the conventional solvent has a solubility gap D 12  between absorbing and regenerating as about 0.08 (mol-CO 2 /mol-amine). The bigger this solubility gap becomes, the more a regeneration amount of carbon dioxide becomes. The amine solvent according to the present embodiment has the solubility gap D 11  about three times as large as the solubility gap D 12  of the conventional solvent, and thus the amine solvent according to the present embodiment can perform regeneration of the absorbed carbon dioxide more efficiently than the conventional solvent. 
     The combustion exhaust gas supplied from the gas introduction port  22  to the absorption tower  2  ascends inside the absorption tower  2 , and absorption liquid (lean liquid) introduced from the absorption liquid introduction port  23  to the absorption tower  2  falls down toward the filler  21 . Further, the combustion exhaust gas supplied to the absorption tower  2  also goes up toward the filler  21 . Thus, the absorption liquid (the lean liquid) is brought into a gas-liquid contact with the combustion exhaust gas while the liquid is falling down along a surface of the filler  21 , so that the liquid selectively absorbs carbon dioxide in the combustion exhaust gas. The combustion exhaust gas (nitrogen and oxygen) that has been removed with carbon dioxide is discharged through a discharge passage L 12  which is connected to a top portion of the absorption tower  2 , and the absorption liquid (the lean liquid) which has absorbed the carbon dioxide is discharged from a discharge port  24  on a bottom part of the absorption tower  2 . 
     The discharge port  24  of the absorption tower  2  is connected with one end of a take-out pipe L 13 , and the other end of the take-out pipe L 13  is connected to the regeneration tower  3 . The absorption liquid (the lean liquid) discharged to the take-out pipe L 13  from the absorption tower  2  passes through a heat exchanger  6  and then is transferred to the regeneration tower  3 . 
     The regeneration tower  3  is for example a countercurrent gas-liquid contact device and is filled inside with a filler  31  such as Raschig ring. 
     The regeneration tower  3  is provided with an absorption liquid introduction port  32  connected with the take-out pipe L 13  above the filler  31 , and the absorption liquid (rich liquid) transferred from the absorption liquid introduction port  32  through the take-out pipe L 13  is supplied. The absorption liquid (the rich liquid) supplied from the absorption liquid introduction port  32  falls down to the filler  31 . 
     The absorption liquid (the rich liquid) is heated to reach a boiling temperature while the liquid is falling down in the regeneration tower, so that the liquid diffuses carbon dioxide with water vapor. Heating of the absorption liquid (the rich liquid) is, for example, performed by a heat pump  7  utilizing waste heat and ambient heat or a heat pump  8  utilizing heat generated when the absorption liquid (the lean liquid) absorbs carbon dioxide in the absorption tower  2 . Inside the regeneration tower  3  is depressurized to about 4 kPa (which will be explained in detail later), for example, and thus the boiling temperature is lowered (the boiling temperature of water is about 29 degrees under a circumstance of about 4 kPa). Accordingly, energy consumption for heating the absorption liquid (the rich liquid) can be suppressed. 
     The absorption liquid (the lean liquid) that has diffused the carbon dioxide is discharged from a discharge port  33  on a bottom part of the regeneration tower  3 . The absorption liquid (the lean liquid) that has been discharged to a take-out pipe L 14  from the regeneration tower  3  passes through the heat exchanger  6  and is then returned to the absorption tower  2 . The take-out pipe L 14  is connected with the absorption liquid introduction port  23  of the absorption tower  2 , and thus the absorption liquid (the lean liquid) that has been returned to the absorption tower  2  falls down to the filler  21  to be reused for absorbing the carbon dioxide. 
     Further, the carbon dioxide and the water vapor which have been diffused are discharged to a first transfer pipe L 15  from a top portion of the regeneration tower  3 . This discharge operation is performed by sucking the carbon dioxide and the water vapor by use of negative pressure generated in the carbon dioxide sublimators  5 A,  5 B (the negative pressure generated in the carbon dioxide sublimators  5 A,  5 B will be explained later). 
     The first transfer pipe L 15  is branched into a branch transfer pipe L 151 A and a branch transfer pipe L 151 B by a switching valve  11 . Through this branching, a carbon dioxide recovery line  10 A configured with a water vapor condenser  4 A and the carbon dioxide sublimator  5 A which are connected in series and a carbon dioxide recovery line  10 B configured with a water vapor condenser  4 B and the carbon dioxide sublimator  5 B which are connected in series are connected in parallel to the regeneration tower  3 . Then, operation of the switching valve  11  allows selection of flow of the carbon dioxide and the water vapor which are discharged from the regeneration tower  3  to either one of the carbon dioxide recovery lines  10 A and  10 B. 
     A configuration of the carbon dioxide recovery line  10 A ( 10 B) is explained in detail. The regeneration tower  3  is connected to the water vapor condenser  4 A ( 4 B) via the first transfer pipe L 15  and the branch transfer pipe L 151 A (L 151 B). Herein, the branch transfer pipe L 151 A (L 151 B) is provided with an open-close valve  13 A ( 13 B) between the switching valve  11  and the water vapor condenser  4 A ( 4 B). 
     The water vapor condenser  4 A ( 4 B) is provided inside with a heat exchanger  41 A ( 41 B). The heat exchanger  41 A is used for cooling the water vapor and the carbon dioxide inside the condenser by a refrigerant flowing through a refrigerant circuit  12 A ( 12 B) which will be explained later. The water vapor condenser  4 A ( 4 B) is further connected with a heat pump  42 A ( 42 B) utilizing waste heat and ambient heat and a drain  43 A ( 43 B). The drain  43 A ( 43 B) is provided with an open-close valve  15 A ( 15 B). 
     Further, the water vapor condenser  4 A ( 4 B) is connected to the carbon dioxide sublimator  5 A ( 5 B) via a second transfer pipe L 16 A (L 16 B). Herein, the second transfer pipe L 16 A (L 16 B) is provided with an open-close valve  14 A ( 14 B) between the water vapor condenser  4 A ( 4 B) and the carbon dioxide sublimator  5 A ( 5 B). 
     The carbon dioxide sublimator  5 A ( 5 B) is provided with a heat exchanger  51 A ( 51 B) inside. The heat exchanger  51 A ( 51 B) is used for cooling the carbon dioxide in the sublimator by the refrigerant flowing through the refrigerant circuit  12 A ( 12 B) which will be explained later. The carbon dioxide sublimator  5 A ( 5 B) is further connected with a heat pump  52 A ( 52 B) utilizing the waste heat and the ambient heat, a drain  53 A ( 53 B), and a take-out pipe  54 A ( 54 B). The drain  53 A ( 53 B) is provided with an open-close valve  16 A ( 16 B), and the take-out pipe  54 A includes an open-close valve  17 A ( 17 B). 
     Further, the carbon dioxide recovery lines  10 A,  10 B are configured with the refrigerant circuits  12 A,  12 B, respectively so that the refrigerant flows in an order of the carbon dioxide sublimators  5 A,  5 B, and the water vapor condensers  4 A,  4 B. Moreover, the refrigerant circuits  12 A,  12 B are integrated after passing the water vapor condensers  4 A,  4 B so that the refrigerant having flown through the water vapor condensers  4 A,  4 B further flows into the absorption tower  2 . As the refrigerant, cold heat after regasification of liquefied fuel (one example of a fluid) is used. The liquefied fuel is, for example, liquefied natural gas, liquid hydrogen, liquefied methane, and others. For example, the cold heat after regasification of the liquefied gas may be used as the refrigerant. The liquefied gas is, for example, exemplified as liquid nitrogen, liquid oxygen, and others. 
     The function of the refrigerant, the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) in the above-configured carbon dioxide recovery device  1  is explained below. 
     The refrigerant passes through the refrigerant circuit  12 A ( 12 B) to firstly be cooled inside the carbon dioxide sublimator  5 A ( 5 B) by the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B). When liquefied natural gas is used as the liquefied fuel, the cold heat is minus 162 degrees centigrade, and when liquid hydrogen is used, the cold heat is minus 253 degrees centigrade. The temperature inside the carbon dioxide sublimator  5 A ( 5 B) is however cooled to a temperature appropriate for sublimation (solidification) of the carbon dioxide by controlling a temperature gap by the heat exchanger  51 A ( 51 B) or by utilizing a separate operation medium or a refrigerant. For example, when combustion exhaust gas from an iron manufacturing plant or a cement plant is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 85 degrees centigrade or below. Further, when the combustion exhaust gas from a power plant is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 96 degrees centigrade or below. Furthermore, when the atmosphere is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 140 degrees centigrade or below. 
     The temperature appropriate for sublimation (solidification) of the carbon dioxide inside the carbon dioxide sublimator  5 A ( 5 B) varies depending on a type of the to-be-separated gas because a partial pressure of the carbon dioxide in the to-be-separated gas is different according to the type of the to-be-separated gas. Herein,  FIG.  15    is a graph showing a range of partial pressure values of carbon dioxide in the combustion exhaust gas (represented as a first combustion exhaust gas in  FIG.  15   ) from the iron manufacturing plant or the cement plant, the combustion exhaust gas (represented as a second combustion exhaust gas in  FIG.  15   ) from the power plant, and in the atmosphere. 
     For example, the maximum partial pressure P 11  of the carbon dioxide in the combustion exhaust gas from the iron manufacturing plant or the cement plant is about 60 kPa. Then, the temperature corresponding to this partial pressure P 11  at which the carbon dioxide is in a gas-solid balanced state is about minus 85 degrees centigrade. Therefore, when the combustion exhaust gas from the iron manufacturing plant or the cement plant is used as the to-be-separated gas, in order to sublimate (solidify) the carbon dioxide, it is preferable to cool it inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature of about minus 85 degrees centigrade or below. 
     Further for example, the maximum partial pressure P 12  of the carbon dioxide in the combustion exhaust gas from the power plant is about 21 kPa. Then, the temperature corresponding to this partial pressure P 12  at which the carbon dioxide is in the gas-solid balanced state is about minus 96 degrees centigrade. Accordingly, when the combustion exhaust gas from the power plant is used as the to-be-separated gas, in order to sublimate (solidify) the carbon dioxide, it is preferable to cool it inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature of about minus 96 degrees centigrade or below. 
     Further for example, the maximum partial pressure P 13  of the carbon dioxide in the atmosphere is about 0.045 kPa. Then, the temperature corresponding to this partial pressure P 13  at which the carbon dioxide is in the gas-solid balanced state is about minus 140 degrees centigrade. Accordingly, when the atmosphere is used as the to-be-separated gas, in order to sublimate (solidify) the carbon dioxide, it is preferable to cool it inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature of about minus 140 degrees centigrade or below. 
     Cooling down the temperature inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature appropriate for sublimation (solidification) of the carbon dioxide causes sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) to form dry ice. The MEA solvent that has remained in sublimation (solidification) is discharged from the drain  53 A ( 53 B) by opening the open-close valve  16 A ( 16 B). Further, when the carbon dioxide that has turned dry ice is to be recovered, the open-close valve  17 A ( 17 B) is opened to bring the carbon dioxide sublimator  5 A ( 5 B) back to the normal temperature so that the dry ice is sublimated (gasified) and recovered from the take-out pipe  54 A ( 54 B). At this time, the open-close valves  14 A ( 14 B),  16 A ( 16 B) are in a valve-closed state so that the sublimated (gasified) carbon dioxide would not flow in any parts other than the take-out pipe  54 A ( 54 B). Then, the thus recovered carbon dioxide is utilized as carbon dioxide gas or the like. 
     When the carbon dioxide is to be recovered, sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B needs to be interrupted. However, as mentioned above, it is selectable to make frow the carbon dioxide and the water vapor that are discharged from the regeneration tower  3  into either one of the carbon dioxide recovery lines  10 A,  10 B. Accordingly, while the carbon dioxide is recovered from the carbon dioxide sublimator  5 A of the one carbon dioxide recovery line  10 A, the carbon dioxide sublimator  5 B of the other carbon dioxide recovery line  10 B can continuously sublimate (solidify) the carbon dioxide. Thus, the carbon dioxide can be further efficiently recovered. 
     When sublimation (solidification) of the carbon dioxide is performed in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to be under negative pressure. Thereby, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump to perform suction of the water vapor and the carbon dioxide that have been diffused in the regeneration tower  3 . This suction creates flow of the water vapor and the carbon dioxide toward the carbon dioxide recovery line  10 A ( 10 B). 
     Further, in accordance with depressurizing of the carbon dioxide sublimator  5 A ( 5 B), the regeneration tower  3  connected in series is also depressurized, so that a boiling temperature of the absorption liquid in the regeneration tower  3  is lowered. Accordingly, consumption energy for heating the absorption liquid can be suppressed. In the present embodiment, the regeneration tower  3  is depressurized to about 4 kPa as mentioned above. The pressure of the regeneration tower  3  is adjusted by a decompression valve  9  provided on the first transfer pipe L 15 . 
     After cooling inside the carbon dioxide sublimator  5 A ( 5 B), the refrigerant subsequently is cooled inside the water vapor condenser  4 A ( 4 B) by the heat exchanger  41 A ( 41 B) provided in the water vapor condenser  4 A ( 4 B). The refrigerant has been raised its temperature by heat exchanging in the heat exchanger  51 A ( 51 B), so that the refrigerant is cooled to about 1 degree centigrade. 
     Since the water vapor condenser  4 A ( 4 B) is about 1 degree centigrade, the carbon dioxide and the water vapor which are sucked by the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B) and thus discharged from the regeneration tower  3  are made to flow into the water vapor condenser  4 A ( 4 B) to be cooled down to about 20 degrees centigrade. Thereby, the water vapor is condensed to become water. The water is stored on a bottom part of the water vapor condenser  4 A ( 4 B), and the thus stored water is discharged through the drain  43 A ( 43 B) by opening the open-close valve  15 A ( 15 B). Herein, the drain  43 A ( 43 B) may be connected to the regeneration tower  3  to reuse the water in the regeneration tower  3 . 
     The carbon dioxide that has flown with the water vapor in the water vapor condenser  4 A ( 4 B) remains as gaseous body in a temperature of about 20 degrees centigrade, and accordingly, the carbon dioxide is sucked by the carbon dioxide sublimator  5 A ( 5 B) so that the carbon dioxide passes through the second transfer pipe L 16 A (L 16 B) and flows in the carbon dioxide sublimator  5 A ( 5 B). Then, the carbon dioxide having flown into the carbon dioxide sublimator  5 A (B) is sublimated (solidified) to become dry ice as mentioned above. 
     Subsequently, the refrigerant is used for cooling the absorption tower  2  after cooling inside the water vapor condenser  4 A ( 4 B). An object of cooling the absorption tower  2  is to restrain temperature increase in the absorption tower  2  due to heat generation that is caused when the absorption liquid absorbs the carbon dioxide. 
     As mentioned above, the carbon dioxide recovery device  1 A according to the first embodiment comprises the separation device  60  to separate carbon dioxide from the to-be-separated gas including the carbon dioxide, wherein the separation device  60  and the carbon dioxide sublimators  5 A,  5 B to sublimate (solidify) the carbon dioxide, which has been separated by the separation device, are connected in series in order from an upstream side of supplying the to-be-separated gas. The carbon dioxide sublimators  5 A,  5 B are connected with the refrigerant circuits  12 A,  12 B in which a fluid having the cold heat is utilized as the refrigerant, and the carbon dioxide is sublimated (solidified) by the refrigerant, and when the carbon dioxide is sublimated (solidified), the carbon dioxide sublimators  5 A,  5 B are depressurized to be under negative pressure so that the carbon dioxide that has been separated by the separation device  60  is sucked. 
     According to the above-mentioned carbon dioxide recovery device  1 A, the separation device  60  for separating the carbon dioxide from the to-be-separated gas and emitting the separated carbon dioxide and the carbon dioxide sublimators  5 A,  5 B for sublimating (solidifying) the carbon dioxide are connected in series. The carbon dioxide separated by the separation device  60  is emitted from the separation device  60  and then flows to the carbon dioxide sublimators  5 A,  5 B. The carbon dioxide having reached the carbon dioxide sublimators  5 A,  5 B is cooled down by the refrigerant, which utilizes the fluid having the cold heat, and then sublimated (solidified). Dry ice generated by this sublimation (solidification) of the carbon dioxide is recovered by sublimating (solidification) again, and thus the carbon dioxide can be utilized as carbon dioxide gas or the like. 
     When the carbon dioxide is to be sublimated (solidified), the carbon dioxide sublimators  5 A,  5 B are depressurized to be under the negative pressure. The carbon dioxide emitted from the separation device  60  is sucked by this negative pressure. This suction causes flow of the carbon dioxide from the separation device  60  to the carbon dioxide sublimators  5 A,  5 B, so that sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B are promoted. Suction of the carbon dioxide is performed by utilizing the fluid having the cold heat, and thus a pump or the like for suction is not necessary and energy conservation can be achieved. This energy conservation further achieves suppression in increase in electric power cost and suppression in generation of further carbon dioxide for power generation. 
     As the fluid having the cold heat, there are provided for example, liquefied fuel and liquefied gas. The liquefied fuel is, for example, liquefied natural gas (LNG), liquid hydrogen, liquefied methane, and others. Natural gas as main material for city gas is imported in a form of LNG and then re-gasified in an LNG terminal and shipped by a gas pipeline. In regasification of the LNG, a large amount of cold heat energy is released, and thus the cold heat energy has attracted attention as unused energy. Accordingly, as mentioned above, utilizing the cold heat of the liquefied fuel for suction of the carbon dioxide results in good use of unused energy, so that a carbon dioxide recovery device can be made ecological. Herein, as the liquefied fuel, liquid hydrogen can be given other than the LNG. Further, the liquefied gas is, for example, liquid nitrogen and liquid oxygen. Furthermore, the fluid having the cold heat is not necessarily in a form of liquid but may be gas, slurry, and gas-liquid multiphase flow. 
     Further, the carbon dioxide recovery device  1 A according to the first embodiment is configured such that the separation device  60  is provided with the absorption tower  2  to bring to-be-separated gas including carbon dioxide and the absorbing liquid for absorbing the carbon dioxide into gas-liquid contact to absorb the carbon dioxide by the absorbing liquid and the regeneration tower  3  configured to emit the carbon dioxide with the water vapor from the absorbing liquid that has absorbed the carbon dioxide. The regeneration tower  3 , the water vapor condensers  4 A,  4 B to condense the water vapor that has been emitted in the regeneration tower  3 , the carbon dioxide sublimators  5 A,  5 B to sublimate (solidify) the carbon dioxide that has been emitted in the regeneration tower are successively connected in series. The water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B are connected to the refrigerant circuits  12 A,  12 B using the fluid having the cold heat as the refrigerant, and the water vapor is condensed and the carbon dioxide is sublimated (solidified) by the refrigerant. The water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B are depressurized to be under negative pressure when the water vapor is condensed and the carbon dioxide is sublimated (solidified), so that the water vapor and the carbon dioxide both having been emitted in the regeneration tower  3  are sucked. 
     According to the above-mentioned carbon dioxide recovery device  1 A, the regeneration tower  3 , the water vapor condensers  4 A,  4 B, and the carbon dioxide sublimators  5 A,  5 B are successively connected in series, and therefore, the carbon dioxide and the water vapor having been emitted in the regeneration tower  3  firstly flow in the water vapor condensers  4 A,  4 B and only the water vapor is cooled by the refrigerant utilizing the fluid having the cold heat and condensed in the water vapor condensers  4 A,  4 B. Then, only the carbon dioxide flows into the subsequent carbon dioxide sublimators  5 A,  5 B. The carbon dioxide having reached the carbon dioxide sublimators  5 A,  5 B is cooled by the refrigerant utilizing the fluid having the cold heat and sublimated (solidified). The dry ice generated by sublimating (solidifying) this carbon dioxide is recovered by sublimating (gasifying) again so as to be made good use of as the carbon dioxide gas or the like. 
     When the carbon dioxide is sublimated (solidified), the water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B are depressurized to be under the negative pressure. By this negative pressure, the water vapor and the carbon dioxide having been emitted in the regeneration tower  3  are sucked, so that the water vapor is made to flow from the regeneration tower  3  to the water vapor condensers  4 A,  4 B and the carbon dioxide is made to flow from the regeneration tower  3  through the water vapor condensers  4 A,  4 B to the carbon dioxide sublimators  5 A,  5 B. 
     In accordance with depressurizing of the water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B, the regeneration tower  3  connected in series is also depressurized, so that the boiling temperature of the absorbing liquid (amine-based solvents) in the regeneration tower  3  is lowered. Therefore, it is possible to suppress the energy consumption for heating the absorbing liquid (amine-based solvents). 
     Further, depressurizing of the regeneration tower  3  is made by utilizing the fluid having the cold heat, and thus electric power for depressurizing the regeneration tower  3  is unnecessary, thereby achieving energy conservation. The achievement in the energy conservation further achieves suppression of further generation of carbon dioxide for power generation. 
     Further, the carbon dioxide recovery device  1 A according to the first embodiment is configured such that the refrigerant circuits  12 A,  12 B are connected as being communicated with the carbon dioxide sublimators  5 A,  5 B, the water vapor condensers  4 A,  4 B, and the absorption tower  2 . The refrigerant flows through the carbon dioxide sublimators  5 A,  5 B, the water vapor condensers  4 A,  4 B, and the absorption tower  2  in this order. 
     According to the above-mentioned carbon dioxide recovery device  1 A, the refrigerant of the fluid having the cold heat that has been utilized for sublimation (solidification) of the carbon dioxide can be further used for condensation of the water vapor and used for cooling the absorption tower  2  thereafter. The absorption tower  2  is cooled down for the purpose of suppressing the temperature increase in the absorption tower  2  which is heated by the heat generated when the absorbing liquid (amino-based solvents) absorbs the carbon dioxide. 
     Further, the carbon dioxide recovery device  1 A according to the first embodiment is configured such that the regeneration tower  3  is connected in parallel with at least the two carbon dioxide recovery lines  10 A,  10 B configured with the water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B which are connected in series. Accordingly, it is possible to further efficiently recover the carbon dioxide. 
     In the carbon dioxide sublimators  5 A,  5 B, dry ice, which is the sublimated (solidified) carbon dioxide, needs to be recovered by regasification or the like, and thus in recovery, sublimation (solidification) of the carbon dioxide needs to be interrupted. To address this, the regeneration tower  3  is connected in parallel with at least the two carbon dioxide recovery lines  10 A,  10 B configured with the water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B which are connected in series, and accordingly, while one of the carbon dioxide recovery lines  10 A,  10 B is recovering the dry ice by sublimating (gasifying) the dry ice again through the carbon dioxide sublimator, the other one of the carbon dioxide recovery lines  10 A,  10 B can be kept operating. This achieves further efficient recovery of the carbon dioxide. 
     Further, the carbon dioxide recovery device  1 A according to the first embodiment is configured with the decompression valve  9  between the regeneration tower  3  and the water vapor condensers  4 A,  4 B. The more the pressure is lowered by cooling the carbon dioxide sublimators  5 A,  5 B, the more quickly the carbon dioxide can turn to the dry ice, and the force for sucking the emitted carbon dioxide and the water vapor can be increased. However, decrease in the pressure of the carbon dioxide sublimators  5 A,  5 B leads to decrease in the pressure of the regeneration tower  3 , so that the excessive decrease in the pressure inside the regeneration tower  3  could cause coexistence state of liquid and solid of the absorbing liquid (amino-based solvents) in the regeneration tower  3 , which could rather degrade the efficiency in emission of the carbon dioxide. To address this, it is preferable to provide the decompression valve between the regeneration tower  3  and the water vapor condensers  4 A,  4 B to enable adjustment of the pressure of the regeneration tower  3  by the decompression valve  9 . 
     Further, the carbon dioxide recovery device  1 A according to the first embodiment is configured such that when the to-be-separated gas is the combustion exhaust gas from an iron manufacturing plant or a cement plant, for example, the carbon dioxide sublimators  5 A,  5 B are cooled down by the refrigerant to about minus 85 degrees centigrade or below, when the to-be-separated gas is the combustion exhaust gas from a power plant, the carbon dioxide sublimators  5 A,  5 B are cooled down by the refrigerant to about minus 96 degrees centigrade or below, and when the to-be-separated gas is the atmosphere, the carbon dioxide sublimators  5 A,  5 B are cooled down by the refrigerant to about minus 140 degrees centigrade or below. 
     The temperature at which the carbon dioxide is in the gas-solid balanced state differs depending on the partial pressure of the carbon dioxide in the to-be-separated gas. Accordingly, by making the temperature inside the carbon dioxide sublimator to the temperature at which the gas-solid balanced state corresponding to the partial pressure value is kept, sublimation (solidification) of the carbon dioxide is started, and thus the carbon dioxide sublimators  5 A,  5 B can be kept under the negative pressure. Thereby, the water vapor and the carbon dioxide which have been emitted in the regeneration tower  3  can be sucked. 
     Second Embodiment 
     Next, a second embodiment of a carbon dioxide recovery device according to the present invention is explained with focus on different points from the carbon dioxide recovery device  1 A according to the first embodiment with reference to the accompanying drawings. 
       FIG.  2    is a schematic view showing a configuration of a carbon dioxide recovery device  1 B according to the second embodiment. The configuration of the absorption tower  2  and the regeneration tower  3  is the same as the carbon dioxide recovery device  1 A according to the first embodiment. The regeneration tower  3  is connected with one water vapor condenser  4  in series via a first transfer pipe L 15 . Then, the water vapor condenser  4  is connected with a second transfer pipe L 16  to discharge carbon dioxide to the carbon dioxide sublimators  5 A,  5 B. 
     The second transfer pipe L 16  is branched off to a branch transfer pipe L 161 A and a branch transfer pipe L 161 B by a switching valve  18 . By this branching, the water vapor condenser  4  is connected in parallel with the carbon dioxide sublimator  5 A and the carbon dioxide sublimator  5 B. Operation of the switching valve  18  enables selection of either one of the carbon dioxide sublimators  5 A,  5 B through which carbon dioxide, which has been discharged from the regeneration tower  3  and has passed through the water vapor condenser  4 , flows. Further, open-close valves  14 A,  14 B are provided on the branch transfer pipes L 161 A, L 161 B, respectively. 
     The carbon dioxide sublimators  5 A,  5 B are communicated with the refrigerant circuits  12 A,  12 B which utilize the cold heat in regasification of liquefied fuel as the refrigerant, respectively. The refrigerant circuits  12 A,  12 B each having passed through the carbon dioxide sublimators  5 A,  5 B are merged so that the refrigerant having flown through the carbon dioxide sublimators  5 A,  5 B further flows through the water vapor condenser  4  and the absorption tower  2  in this order. 
     According to the above-mentioned carbon dioxide recovery device  1 B, too, when carbon dioxide is sublimated (solidified) in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to become under negative pressure. Thus, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump, and thereby the water vapor and the carbon dioxide that have been emitted in the regeneration tower  3  are sucked. This suction causes flow of the water vapor from the regeneration tower  3  to the water vapor condenser  4  and causes flow of the carbon dioxide from the regeneration tower  3  through the water vapor condenser  4  to the carbon dioxide sublimator  5 A ( 5 B). 
     Further, in accordance with decompression of the carbon dioxide sublimator  5 A ( 5 B), the regeneration tower  3  connected in series is also decompressed, so that the boiling temperature of the absorbing liquid in the regeneration tower  3  is lowered. Therefore, the consumption energy for heating the absorbing liquid can be suppressed. 
     Further, when the carbon dioxide having turned into dry ice is to be recovered from the carbon dioxide sublimator  5 A ( 5 B), sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) needs to be stopped. However, the switching valve  18  makes it possible to select either one of the carbon dioxide sublimators  5 A,  5 B through which the carbon dioxide, which has been discharged from the regeneration tower  3  and has passed through the water vapor sublimator  4 , flows. Accordingly, when the carbon dioxide is to be recovered from the one carbon dioxide sublimator  5 A, the other carbon dioxide sublimator  5 B can keep performing sublimation (solidification) of the carbon dioxide. Therefore, the carbon dioxide can be recovered more efficiently. 
     As mentioned above, the carbon dioxide recovery device  1 B according to the second embodiment is configured such that the regeneration tower  3  is connected with the one water vapor condenser  4 , and the water vapor condenser  4  is connected in parallel with at least the two carbon dioxide sublimators  5 A,  5 B. 
     According to the above-mentioned carbon dioxide recovery device  1 B, the regeneration tower  3  is connected with the one water vapor condenser  4 , and the water vapor condenser  4  is connected in parallel with at least the two carbon dioxide sublimators  5 A,  5 B. Accordingly, when the dry ice is to be recovered by one of the carbon dioxide sublimators  5 A,  5 B by regasification and others, the other one of the carbon dioxide sublimators  5 A,  5 B may be kept operating, achieving further efficient recovery of the carbon dioxide. 
     Third Embodiment 
     Next, a third embodiment of a carbon dioxide recovery device according to the present invention is explained in detail with reference to the accompanying drawings.  FIG.  3    is a schematic view of a configuration of a carbon dioxide recovery device  50 A according to the third embodiment. 
     The carbon dioxide recovery device  50 A is provided with separation devices  70 A,  70 B and the carbon dioxide sublimators  5 A,  5 B as shown in  FIG.  3   . The separation device  70 A is connected in series with the carbon dioxide sublimator  5 A, and the separation device  70 B is connected in series with the carbon dioxide sublimator  5 B. Herein, the separation device  70 A and the separation device  70 B are the same devices, and the carbon dioxide sublimator  5 A and the carbon dioxide sublimator  5 B are the same devices. 
     The separation devices  70 A,  70 B are stored inside with adsorbents  701 A,  701 B to adsorb carbon dioxide. As the adsorbent, for example, there are used zeolite (for example, a molecular sieve 13X of UNION SHOWA K.K., and NSA-700 of Tosoh Corporation), amino-impregnated solid sorbent (porous substance carried with amine compound), gate-type sorbent (ELM-11 [Cu (bpy) 2 (BF 4 ) 2 ], and others. The separation devices  70 A,  70 B are provided with gas introduction ports  702 A,  702 B below the sorbents  701 A,  701 B, respectively, and the gas introduction ports  702 A,  702 B are connected with a gas supply passage L 11  to supply the combustion exhaust gas (one example of the to-be-separated gas) to the separation devices  70 A,  70 B. To be more specific, the gas supply passage L 11  is branched off by a switching valve  19  to a branch gas supply passage L 111  and a branch gas supply passage L 112 , and the branch gas supply passage L 111  is connected to the gas introduction port  702 A of the separation device  70 A and the branch gas supply passage L 112  is connected to the gas introduction port  702 B. 
     The branch gas supply passage L 111  is provided with an open-close valve  20 A and the branch gas supply passage L 112  is provided with an open-close valve  20 B, and the combustion exhaust gas is supplied to the separation devices  70 A,  70 B by bringing the open-close valves  20 A,  20 B in a valve-open state. This combustion exhaust gas is the one utilizing the combustion exhaust gas generated in power generation and natural gas purification and the combustion exhaust gas generated from a combustor, a blast furnace, and others. The combustion exhaust gas includes about 10 to 20% of carbon dioxide and further includes nitrogen, oxygen, and others. 
     Further, the gas supply passage L 11  is branched off by the switching valve  19  so that the gas supply passage L 11  is connected in parallel with a carbon dioxide recovery line  500 A and a carbon dioxide recovery line  500 B. The carbon dioxide recovery line  500 A is configured such that the separation device  70 A and the carbon dioxide sublimator  5 A are connected in series in this order from an upstream side of supplying the combustion exhaust gas. The carbon dioxide recovery line  500 B is configured such that the separation device  70 B and the carbon dioxide sublimator  5 B are connected in series in this order from the upstream side of supplying the combustion exhaust gas. Operation of the switching valve  19  makes it possible to select either one of the carbon dioxide recovery line  500 A and the carbon dioxide recovery line  500 B through which the combustion exhaust gas supplied from the gas supply passage L 11  is made flow. 
     The combustion exhaust gas supplied from the gas introduction port  702 A ( 702 B) ascends in the separation device  70 A ( 70 B) and comes to contact with the adsorbent  701 A ( 701 B) stored in the separation device  70 A ( 70 B). Then, the adsorbent  701 A ( 701 B) selectively adsorbs the carbon dioxide included in the combustion exhaust gas. By this adsorption, the carbon dioxide is separated from the combustion exhaust gas. Herein, the adsorbent  701 A ( 701 B) such as zeolite has a concern about degradation in the adsorption performance when the adsorbent takes in moisture, and thus it is conceivable to provide a water vapor removal device (not shown) on the gas supply passage L 11  and supply the combustion exhaust gas, which has been removed with the water vapor by the water vapor removal device, to the separation device  70 A ( 70 B). Further, the combustion exhaust gas is conceived to include sulfur oxide, and thus a desulfurization unit (not shown) may be provided on the gas supply passage L 11  so that the combustion exhaust gas which has been removed with the sulfur oxide is supplied to the separation device  70 A ( 70 B). 
     Then, the combustion exhaust gas (nitrogen and oxygen) which has been separated from the carbon dioxide is discharged from a discharge port  704 A ( 704 B) provided on a top portion of the separation device  70 A ( 70 B) to a discharge passage L 12 A (L 12 B). 
     The adsorbent  701 A ( 701 B) has its determined capacity of adsorbable amount of carbon dioxide by its volume or the like, and thus the adsorbent  701 A ( 701 B) which has absorbed a certain amount of the carbon dioxide cannot further adsorb the carbon dioxide. Accordingly, in order to adsorb further carbon dioxide, the adsorbent  701 A ( 701 B) needs to be desorbed. The desorption needs to be performed by placing the adsorbent  701 A ( 701 B) under the decompressed state, and accordingly, inside of the separation device  70 A ( 70 B) is decompressed. The carbon dioxide desorbed from the adsorbent  701 A ( 701 B) is diffused from a diffusion port  703 A ( 703 B) provided on atop portion of the separation device  70 A ( 70 B). Then, the adsorbent  701 A ( 701 B) that has been desorbed from the carbon dioxide is brought into contact with the combustion exhaust gas supplied from the gas introduction port  702 A ( 702 B) so that the adsorbent  701 A ( 701 B) can adsorb further carbon dioxide. 
     The diffusion port  703 A ( 703 B) is connected with the transfer pipe L 15 A (L 15 B), and the carbon dioxide diffused from the diffusion port  703 A ( 703 B) is discharged to the transfer pipe L 15 A. This discharge is performed by sucking the carbon dioxide by the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B) (the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B) will be explained below). 
     The carbon dioxide sublimator  5 A ( 5 B) is connected with the separation device  70 A ( 70 B) via the transfer pipe L 15 A (L 15 B) so that the carbon dioxide diffused from the separation device  70 A ( 70 B) can flow to the carbon dioxide sublimator  5 A ( 5 B). The transfer pipe L 15 A is provided with a decompression valve  9 A and an open-close valve  14 A in this order from an upstream side between the separation device  70 A and the carbon dioxide sublimator  5 A, and the transfer pipe L 15 B is provided with a decompression valve  9 B and an open-close valve  14 B between the separation device  70 B and the carbon dioxide sublimator  5 B. Herein, the decompression valve  9 A and the decompression valve  9 B are identical devices, and the open-close valve  14 A and the open-close valve  14 B are identical devices. 
     The carbon dioxide sublimator  5 A ( 5 B) is provided inside with a heat exchanger  51 A ( 51 B). The heat exchanger  51 A ( 51 B) is used for cooling the carbon dioxide therein by use of the refrigerant flowing through the refrigerant circuit  12 A ( 12 B). The carbon dioxide sublimator  5 A ( 5 B) is further connected with a heat pump  52 A ( 52 B) utilizing waste heat and ambient heat, a drain  53 A ( 53 B), and a take-out pipe  54 A ( 54 B). The drain  53 A ( 53 B) is provided with an open-close valve  16 A ( 16 B), and the take-out pipe  54 A ( 54 B) is provided with an open-close valve  17 A ( 17 B). 
     The refrigerant circuit  12 A ( 12 B) is configured to make the refrigerant flow inside the carbon dioxide sublimator  5 A ( 5 B). As the refrigerant, the cold heat after regasification of liquefied fuel (one example of fluid) is used. The liquefied fuel is, for example, exemplified by liquefied natural gas, liquid hydrogen, and liquefied methane. Further, as the refrigerant, the cold heat after regasification of the liquefied gas may be used. The liquefied gas is, for example, exemplified by liquefied nitrogen and liquefied oxygen. 
     Function of the refrigerant and the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery device  50 A having the above-mentioned configuration is explained below. 
     The refrigerant passes through the refrigerant circuit  12 A ( 12 B) to cool the inside of the carbon dioxide sublimator  5 A ( 5 B) by the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B). When liquefied natural gas is used as the liquefied fuel, the cold heat is minus 162 degrees centigrade, and when liquid hydrogen is used, the cold heat is minus 253 degrees centigrade. The temperature inside the carbon dioxide sublimator  5 A ( 5 B) is however cooled to a temperature appropriate for sublimation (solidification) of the carbon dioxide by controlling a temperature gap by the heat exchanger  51 A ( 51 B) or by utilizing a separate operation medium or a refrigerant. For example, when combustion exhaust gas from an iron manufacturing plant or a cement plant is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 85 degrees centigrade or below. Further, when combustion exhaust gas from a power plant is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 96 degrees centigrade or below. Furthermore, when the atmosphere is used as the to-be-separated gas, the temperature inside the carbon dioxide sublimator  5 A ( 5 B) is preferably cooled to about minus 140 degrees centigrade or below. 
     By cooling down the temperature inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature appropriate for sublimation (solidification) of the carbon dioxide, the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (solidified) to become dry ice. In sublimation (solidification), there is a case that a minute amount of moisture remains in the carbon dioxide sublimator  5 A ( 5 B), but the thus remaining moisture is discharged from the drain  53 A ( 53 B) by opening the open-close valve  16 A ( 16 B). Further, when the carbon dioxide that has become dry ice is to be recovered, the open-close valve  17 A ( 17 B) is opened to bring the carbon dioxide sublimator  5 A ( 5 B) back to the normal temperature so that the dry ice is sublimated (gasified) and recovered from the take-out pipe  54 A ( 54 B). At this time, the open-close valves  14 A ( 14 B),  16 A ( 16 B) are in a valve-closed state so that the sublimated (gasified) carbon dioxide would not flow in any parts other than the take-out pipe  54 A ( 54 B). Then, the thus recovered carbon dioxide is utilized as carbon dioxide gas or the like. 
     Further, when the carbon dioxide is to be recovered, sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B needs to be interrupted. However, as mentioned above, it is selectable to make flow the combustion exhaust gas supplied from the gas supply passage L 11  into either one of the carbon dioxide recovery lines  500 A,  500 B by the switching valve  19 . Accordingly, while the carbon dioxide is being recovered from the carbon dioxide sublimator  5 A of the one carbon dioxide recovery line  500 A, the carbon dioxide sublimator  5 B of the other one carbon dioxide recovery line  500 B can continuously sublimate (solidify) the carbon dioxide, and vice versa. Therefore, the carbon dioxide can be further efficiently recovered. 
     When sublimation (solidification) of the carbon dioxide is performed in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to be under negative pressure. Thereby, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump to perform suction of the carbon dioxide that have been diffused from the separation device  70 A ( 70 B). This suction creates flow of the carbon dioxide from the separation device  70 A ( 70 B) to the carbon dioxide sublimator  5 A ( 5 B), so that sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is promoted. 
     While desorption of the adsorbent  701 A ( 701 B) is performed under the decompressed state, in accordance with decompression of the carbon dioxide sublimator  5 A ( 5 B), the separation device  70 A ( 70 B) connected in series with the carbon dioxide sublimator  5 A ( 5 B) is also depressurized to about 4 kPa. Accordingly, there is no need to provide a pump or the like to depressurize the separation device  70 A ( 70 B). In other words, no electric power for operating a pump or the like is required, thereby achieving energy conservation. Then, conservation in energy can achieve suppression of increase in the electric power cost and suppression of generation of further carbon dioxide for power generation. Herein, the pressure of the separation device  70 A ( 70 B) is adjusted by the decompression valve  9 A ( 9 B) provided on the transfer pipe L 15 A (L 15 B). 
     Modified Example of Third Embodiment 
     Next, a carbon dioxide recovery device  50 B according to a modified example of the third embodiment is explained with reference to  FIG.  4   .  FIG.  4    is a schematic view of a configuration of the carbon dioxide recovery device  50 B according to the modified example of the third embodiment. 
     The carbon dioxide recovery line  500 A ( 500 B) of the carbon dioxide recovery device  50 A according to the above-mentioned third embodiment is configured with the separation device  70 A ( 70 B) and the carbon dioxide sublimator  5 A ( 5 B) which are connected in series. On the other hand, a carbon dioxide recovery line  500 C ( 500 D) in the carbon dioxide recovery device  50 B is configured with the separation device  70 A ( 70 B), the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) connected in series in this order from an upstream side of supplying the combustion exhaust gas. 
     There is a concern about the adsorbent  701 A ( 701 B) such as zeolite, about decline in adsorption performance when it adsorbs moisture, and thus the carbon dioxide recovery device  50 A is configured such that the combustion exhaust gas that has been removed with water vapor in advance is supplied to the separation device  70 A ( 70 B). However, in recent years, an adsorbent, which hardly lowers its adsorption performance even after the adsorbent adsorbs moisture, has been studied and developed. When such an adsorbent (for example, amine-impregnated solid sorbent) is used for the separation device  70 A ( 70 B), it is conceivable to supply the combustion exhaust gas including water vapor to the separation device  70 A ( 70 B). 
     When the combustion exhaust gas including the water vapor is to be supplied to the separation device  70 A ( 70 B), in diffusing the carbon dioxide from the separation device  70 A ( 70 B), it is assumed that the water vapor is diffused with the carbon dioxide. If the water vapor is solidified with the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B), recovery of the carbon dioxide becomes difficult. To address this, the separation device  70 A ( 70 B), the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) are connected in series as the carbon dioxide recovery device  50 B so that the carbon dioxide and the water vapor diffused from the separation device  70 A ( 70 B) firstly flow in the water vapor condenser  4 A ( 4 B) and only the water vapor is cooled by the refrigerant and condensed in the water vapor condenser  4 A ( 4 B). The water vapor is firstly condensed, and accordingly only the carbon dioxide flows to the subsequent carbon dioxide sublimator  5 A ( 5 B) and is cooled by the refrigerant and sublimated (solidified) in the carbon dioxide sublimator  5 A ( 5 B). Thus, recovery of the carbon dioxide is made easily. 
     The separation device  70 A ( 70 B) stores the adsorbent  701 A ( 701 B) therein. The adsorbent is the one hardly lowering its adsorption performance of adsorbing the carbon dioxide even if the moisture (for example, amine-impregnated solid sorbent) is included. Other configuration of the separation device  70 A ( 70 B) is identical with the separation device  70 A ( 70 B) of the carbon dioxide recovery device  50 A, and thus its explanation is omitted. 
     The separation device  70 A ( 70 B) is connected with the water vapor condenser  4 A ( 4 B) via the first transfer pipe L 15 A (L 15 B) so that the carbon dioxide and the water vapor which are diffused from the separation device  70 A ( 70 B) are allowed to flow in the water vapor condenser  4 A ( 4 B). Herein, the first transfer pipe L 15 A is provided with the decompression valve  9 A and the open-close valve  13 A in this order from the upstream side between the separation device  70 A and the water vapor condenser  4 A. The first transfer pipe L 15 B is provided with the decompression valve  9 B and the open-close valve  13 B in this order from the upstream side between the separation device  70 B and the water vapor condenser  4 B. 
     The water vapor condenser  4 A ( 4 B) is provided with the heat exchanger  41 A ( 41 B) inside. The heat exchanger  41 A is used for cooling the water vapor and the carbon dioxide that have reached the water vapor condenser  4 A ( 4 B) from the separation device  70 A ( 70 B) by the refrigerant flowing in the refrigerant circuit  12 A ( 12 B). The water vapor condenser  4 A ( 4 B) is further connected with the heat pump  42 A ( 42 B) utilizing the waste heat and the ambient heat and the drain  43 A ( 43 B). The drain  43 A ( 43 B) includes the open-close valve  15 A ( 15 B). 
     Further, the water vapor condenser  4 A ( 4 B) is connected with the carbon dioxide sublimator  5 A ( 5 B) via the second transfer pipe L 16 A (L 16 B). Further, the second transfer pipe L 16 A (L 16 B) is provided with the open-close valve  14 A ( 14 B) between the water vapor condenser  4 A ( 4 B) and the carbon dioxide sublimator  5 A ( 5 B). 
     The carbon dioxide sublimator  5 A ( 5 B) is a device identical with the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery device  50 A to sublimate (solidify) the carbon dioxide by the refrigerant flowing in the refrigerant circuit  12 A ( 12 B) by use of the heat exchanger  51 A ( 51 B) provided therein. 
     The refrigerant circuit  12 A ( 12 B) is configured to make flow the refrigerant in the order of the carbon dioxide sublimator  5 A ( 5 B) and the water vapor condenser  4 A ( 4 B). The one used for the refrigerant is the cold heat after regasification of the liquefied fuel (one example of fluid) as similar to the carbon dioxide recovery device  50 A. 
     Function of the refrigerant, the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery device  50 B having the above-mentioned configuration is explained below. 
     The refrigerant passes through the refrigerant circuit  12 A ( 12 B) to firstly cool the inside of the carbon dioxide sublimator  5 A ( 5 B) to the temperature appropriate for sublimation (solidification) of the carbon dioxide by the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B) so that the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (solidified). This is similar to the carbon dioxide recovery device  50 A. Herein, the temperature appropriate for sublimation (solidification) of the carbon dioxide is about minus 85 degrees centigrade or below when the combustion exhaust gas from an iron manufacturing plant or a cement plate is used as the to-be-separated gas, about minus 96 degrees centigrade or below when the combustion exhaust gas from a power plant is used as the to-be-separated gas, and about minus 140 degrees centigrade or below when the atmosphere is used as the to-be-separated gas. 
     When sublimation (solidification) of the carbon dioxide is performed in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to be under negative pressure. Thereby, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump to perform suction of the water vapor and the carbon dioxide that have been diffused from the separation device  70 A ( 70 B). This suction creates flow of the water vapor and the carbon dioxide toward the water vapor condenser  4 A ( 4 B) and the carbon dioxide sublimator  5 A ( 5 B). 
     Further, in association with decompression of the carbon dioxide sublimator  5 A ( 5 B), the separation device  70 A ( 70 B) connected in series with the carbon dioxide sublimator  5 A ( 5 B) is depressurized to about 4 kPa, which is similar to the carbon dioxide recovery device  50 A. 
     After cooling inside the carbon dioxide sublimator  5 A ( 5 B), the refrigerant flows to the water vapor condenser  4 A ( 4 B) to cool the inside of the water vapor condenser  4 A ( 4 B) by the heat exchanger  41 A ( 41 B) of the water vapor condenser  4 A ( 4 B). The temperature of the refrigerant has increased by heat exchanging in the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B), and thus inside the water vapor condenser  4 A ( 4 B) is cooled down to about 1 degree centigrade. 
     Since the water vapor condenser  4 A ( 4 B) is about 1 degree centigrade, the carbon dioxide and the water vapor which are sucked by the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B) and discharged from the separation device  70 A ( 70 B) are made to flow into the water vapor condenser  4 A ( 4 B) to be cooled down to about 20 degrees centigrade. Thereby, the water vapor is condensed to become water. The water is stored on a bottom part of the water vapor condenser  4 A ( 4 B), and the thus stored water is discharged through the drain  43 A ( 43 B) by opening the open-close valve  15 A ( 15 B). 
     The carbon dioxide that has flown with the water vapor in the water vapor condenser  4 A ( 4 B) remains as gaseous body in a temperature about 20 degrees centigrade, and accordingly, the carbon dioxide is sucked by the carbon dioxide sublimator  5 A ( 5 B), so that the carbon dioxide passes through the second transfer pipe L 16 A (L 16 B) and flows in the carbon dioxide sublimator  5 A ( 5 B). Then, the carbon dioxide having flown in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (gasified) as mentioned above. 
     As mentioned above, the carbon dioxide recovery device  50 A according to the third embodiment or the carbon dioxide recovery device  50 B according to the modified example is configured such that the separation devices  70 A,  70 B store the adsorbents  701 A,  701 B adsorbing carbon dioxide and is configured to separate the carbon dioxide from the to-be-separated gas by adsorbing the carbon dioxide included in the to-be-separated gas (for example, the combustion exhaust gas) that has been supplied to the separation devices  70 A,  70 B. 
     According to the above-mentioned carbon dioxide recovery devices  50 A,  50 B, the separation devices  70 A,  70 B store the adsorbent (such as zeolite, amine-impregnated solid sorbent, and gate-type sorbent)  701 A,  701 B that can adsorb the carbon dioxide, respectively, and accordingly, the carbon dioxide can be separated from the to-be-separated gas by adsorbing the carbon dioxide included in the to-be-separated gas. Then, the carbon dioxide adsorbed by the adsorbents  701 A,  701 B can be recovered by desorbing from the adsorbents  701 A,  701 B. This desorption is generally performed under the depressurized state, but the separation devices  70 A,  70 B connected in series with the carbon dioxide sublimators  5 A,  5 B are also decompressed in accordance with decompression of the carbon dioxide sublimators  5 A,  5 B by the refrigerant, and accordingly, there is no need to provide a pump or the like to decompress the separation devices  70 A,  70 B. In other words, electric power for operating the pump or the like is not necessary, thereby achieving energy conservation. The energy conservation further achieves suppression of increase in the electric power cost and suppression of generation of further carbon dioxide for power generation. 
     Further, the carbon dioxide recovery device  50 A according to the third embodiment and the carbon dioxide recovery device  50 B according to the modified example are configured such that the separation devices  70 A,  70 B are configured to emit water vapor with the carbon dioxide. The carbon dioxide recovery devices  50 A,  50 B include the water vapor condensers  4 A,  4 B to condense the water vapor. The separation devices  70 A,  70 B, the water vapor condensers  4 A,  4 B, and the carbon dioxide sublimators  5 A,  5 B are connected in series in order from an upstream side of supplying the to-be-separated gas (for example, the combustion exhaust gas). The refrigerant circuits  12 A,  12 B are connected to the water vapor condensers  4 A,  4 B and the carbon dioxide sublimators  5 A,  5 B, respectively, and the water vapor is condensed and the carbon dioxide is sublimated (solidified) by the refrigerant. 
     When the water vapor is emitted with the carbon dioxide from the separation devices  70 A,  70 B, recovery of the carbon dioxide becomes difficult if the water vapor is solidified with the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B. To address this, as the carbon dioxide recovery devise  50 B, the separation devices  70 A,  70 B, the water vapor condensers  4 A,  4 B, and the carbon dioxide sublimators  5 A,  5 B are connected in series, respectively, so that the carbon dioxide and the water vapor emitted from the separation devices  70 A,  70 B first flow to the water vapor condensers  4 A,  4 B, and only the water vapor is cooled by the refrigerant and condensed in the water vapor condenser. The water vapor is first condensed, and thus only the carbon dioxide flows to the subsequent carbon dioxide sublimators  5 A,  5 B to be cooled by the refrigerant and sublimated (solidified) in the carbon dioxide sublimators  5 A,  5 B. Thereby, recovery of the carbon dioxide is made easily. 
     Page 31: 
     Fourth Embodiment 
     Next, a carbon dioxide recovery device  100 A according to a fourth embodiment is explained with reference to  FIG.  5    as for different features from the carbon dioxide recovery devices  50 A,  50 B according to the third embodiment.  FIG.  5    is a schematic view of a configuration of the carbon dioxide recovery device  100 A according to the fourth embodiment. 
     The carbon dioxide recovery device  100 A is provided with a separation device  80  and the carbon dioxide sublimators  5 A,  5 B. The two carbon dioxide sublimators  5 A,  5 B are the identical devices. 
     The separation device  80  retains a permeable membrane  803  therein to selectively transmit carbon dioxide. As the permeable membrane  803 , for example, an inorganic membrane such as a zeolite membrane (such as a high silica CHA zeolite membrane and DDR zeolite membrane) and an organic membrane such as a molecular gate membrane are used. This permeable membrane  803  divides inside of the separation device  80  into a non-transmission side  801  and a transmission side  802 . The non-transmission side  801  is provided with a gas introduction port  804 , and the gas introduction port  804  is connected with the gas supply passage L 11 . Thus, the combustion exhaust gas can be supplied to the separation device  80  (the non-transmission side  801 ). Herein, the combustion exhaust gas to be supplied to this separation device  80  (the non-transmission side  801 ) is the one that has been removed with water vapor and sulfur oxide by a not-shown water vapor removal device and a not-shown desulfurization device which are provided on the gas supply passage L 11 . 
     The transmission side  802  is used to selectively transmit the carbon dioxide. Namely, among components included in the combustion exhaust gas to be supplied to the separation device  80  (the non-transmission side  801 ), only carbon dioxide can move to the transmission side  802 , and nitrogen and oxygen other than the carbon dioxide are not allowed to transmit the permeable membrane  803  and reside in the non-transmission side  801 . 
     Further, the non-transmission side  801  is provided with a discharge port  806 , and the discharge port  806  is connected with a discharge passage L 12  to discharge nitrogen, oxygen, and others remaining in the non-transmission side  801 . Furthermore, the discharge passage L 12  includes an open-close valve  81 . 
     The transmission side  802  is provided with a diffusion port  805  to diffuse the carbon dioxide that has passed through the permeable membrane  803 . The diffusion port  805  is connected with a transfer pipe L 15  so that the carbon dioxide diffused from the discharge port  805  is discharged to the transfer pipe L 15 . This discharge is performed by suction of the carbon dioxide sucked by the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B). 
     The transfer pipe L 15  is branched off by the switching valve  11  to the branch transfer pipe L 151 A and the branch transfer pipe L 151 B. By this branching, the separation device  80  (the transmission side  802 ) is connected with the carbon dioxide sublimator  5 A via the transfer pipe L 15  and the branch transfer pipe L 151 A and connected with the carbon dioxide sublimator  5 B via the transfer pipe L 15  and the branch transfer pipe L 151 B. Then, operation of the switching valve  11  makes it possible to select either one of the carbon dioxide sublimators  5 A,  5 B through which the carbon dioxide discharged from the separation device  80  flows. Herein, the branch transfer pipe L 151 A (L 151 B) is provided with an open-close valve  14 A ( 14 B) between the switching valve  11  and the carbon dioxide sublimator  5 A ( 5 B). 
     The carbon dioxide sublimator  5 A ( 5 B) is identical with the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery devices  50 A,  50 B and is configured to sublimate (solidify) the carbon dioxide by the refrigerant flowing in the refrigerant circuit  12 A ( 12 B) by use of the heat exchanger  51 A ( 51 B) inside the device. The refrigerant circuit  12 A ( 12 B) is also identical with the refrigerant circuit  12 A ( 12 B) in the carbon dioxide recovery device  50 A, and thus explanation thereof is omitted. 
     Function of the refrigerant and the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery device  100 A having the above-mentioned configuration is explained below. 
     The refrigerant passes through the refrigerant circuit  12 A ( 12 B) to cool the inside of the carbon dioxide sublimator  5 A ( 5 B) to the temperature appropriate for sublimation (solidification) of the carbon dioxide by the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B) so that the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (solidified). This is similar to the carbon dioxide recovery device  50 A. Herein, the temperature appropriate for sublimation (solidification) of the carbon dioxide is about minus 85 degrees centigrade or below when the combustion exhaust gas from an iron manufacturing plant or a cement plant is used as the to-be-separated gas, about minus 96 degrees centigrade or below when the combustion exhaust gas from a power plant is used as the to-be-separated gas, and about minus 140 degrees centigrade or below when the atmosphere is used as the to-be-separated gas. 
     When the carbon dioxide is to be recovered, sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B needs to be interrupted. However, as mentioned above, it is selectable to make flow the combustion exhaust gas discharged from the separation device  80  into either one of the carbon dioxide sublimators  5 A,  5 B by the switching valve  11 . Accordingly, while the carbon dioxide is being recovered from the one carbon dioxide sublimator  5 A, the other carbon dioxide sublimator  5 B can continuously sublimate (solidify) the carbon dioxide, and vice versa. Therefore, the carbon dioxide can be further efficiently recovered. 
     When sublimation (solidification) of the carbon dioxide is performed in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to be under negative pressure. Thereby, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump to perform suction of the carbon dioxide that have been diffused from the separation device  80 . This suction creates flow of the carbon dioxide from the separation device  80  to the carbon dioxide sublimator  5 A ( 5 B), so that sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is promoted. 
     While the carbon dioxide sublimator  5 A ( 5 B) is decompressed, the separation device  80  (the transmission side  802 ) connected in series with the carbon dioxide sublimator  5 A ( 5 B) is also depressurized to about 4 kPa. Accordingly, even if a pump or the like to depressurize the separation device  80  (the transmission side  802 ) is not provided, the carbon dioxide included in the combustion exhaust gas supplied to the non-transmission side  801  of the separation device  80  is sucked by the transmission side  802 , so that separation of the carbon dioxide is promoted. In other words, no electric power for operating the pump or the like is required, thereby achieving energy conservation. Then, conservation in energy can achieve suppression of increase in the electric power cost and achieve suppression of generation of further carbon dioxide for power generation. The pressure of the separation device  80  is adjusted by the decompression valve  9  provided on the transfer pipe L 15 . Herein, when this separation of carbon dioxide is to be performed, the open-close valve  18  is closed to prevent backflow from the discharge passage L 12  to the separation device  80 . Then, in a case when the non-transmission side  801  is filled with nitrogen, oxygen, and others other than the carbon dioxide and no any further combustion exhaust gas is allowed to be supplied to the non-transmission side  801 , the open-close valve  81  is opened to discharge the nitrogen, oxygen, and others. 
     Modified Example of Fourth Embodiment 
     Next, a carbon dioxide recovery device  100 B according to a modified example of the fourth embodiment is explained in detail with reference to  FIG.  6   .  FIG.  6    is a schematic view of a configuration of the carbon dioxide recovery device  100 B according to the modified example of the fourth embodiment. 
     The carbon dioxide recovery device  100 B is configured with the separation device  80 , the carbon dioxide recovery line  10 A in which the water vapor condenser  4 A and the carbon dioxide sublimator  5 A are connected in series, and the carbon dioxide recovery line  10 B in which the water vapor condenser  4 B and the carbon dioxide sublimator  5 B are connected in series. 
     When combustion exhaust gas including water vapor is supplied to the separation device  80 , in performing diffusion of the carbon dioxide from the separation device  80 , it is assumed that the water vapor could be diffused with the carbon dioxide. If the water vapor is solidified with the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B), recovery of the carbon dioxide becomes difficult. To address this, as the carbon dioxide recovery device  100 B, the separation device  80 , the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) are connected in series so that the carbon dioxide and the water vapor diffused from the separation device  80  firstly flow in the water vapor condenser  4 A ( 4 B), and only the water vapor is cooled down by the refrigerant and condensed in the water vapor condenser  4 A ( 4 B). The water vapor is firstly condensed, and thus only the carbon dioxide flows to the subsequent carbon dioxide sublimator  5 A ( 5 B) and only this carbon dioxide is cooled by the refrigerant and sublimated (solidified) in the carbon dioxide sublimator  5 A ( 5 B). Thereby, recovery of the carbon dioxide is made easy. 
     The separation device  80  is the one identical with the separation device  80  in the above-mentioned carbon dioxide recovery device  100 A. The carbon dioxide and the water vapor diffused from the separation device  80  are discharged to the first transfer pipe L 15 . This discharge is made by sucking the carbon dioxide and the water vapor by the negative pressure generated in sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B. 
     The first transfer pipe L 15  is branched off by the switching valve  11  to the branch transfer pipe L 151 A and the branch transfer pipe L 151 B. By this branching of the pipe, the separation device  80  (the transmission side  802 ) is connected with the carbon dioxide recovery line  10 A formed of the water vapor condenser  4 A and the carbon dioxide sublimator  5 A via the first transfer pipe L 15  and the branch transfer pipe L 51 A and connected with the carbon dioxide recovery line  10 B formed of the water vapor condenser  4 B and the carbon dioxide sublimator  5 B via the first transfer pipe L 15  and the branch transfer pipe L 151 B. Then, operation of the switching valve  11  allows selection of flow of the carbon dioxide and the water vapor which are diffused from the separation device  80  (the transmission side  802 ) to either one of the carbon dioxide recovery lines  10 A and  10 B. Herein, the branch transfer pipe L 151 A (L 151 B) is provided with the open-close valve  13 A ( 13 B) between the switching valve  11  and the water vapor condenser  4 A ( 4 B). 
     The water vapor condenser  4 A ( 4 B) is the one identical with the water vapor condenser  4 A ( 4 B) in the carbon dioxide recovery device  50 B to condense the water vapor by the refrigerant flowing in the refrigerant circuit  12 A ( 12 B) by use of the heat exchanger  41 A ( 41 B) provided therein. The water vapor condenser  4 A ( 4 B) is connected to the carbon dioxide sublimator  5 A ( 5 B) via the second transfer pipe L 16 A (L 16 B). Herein, the second transfer pipe L 16 A (L 16 B) is provided with the open-close valve  14 A ( 14 B) between the water vapor condenser  4 A ( 4 B) and the carbon dioxide sublimator  5 A ( 5 B). 
     The carbon dioxide sublimator  5 A ( 5 B) is the one identical with the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery devices  50 A,  50 B, and  100 A to sublimate (solidify) the carbon dioxide by the refrigerant flowing in the refrigerant circuit  12 A ( 12 B) by use of the heat exchanger  51 A ( 51 B) provided therein. 
     Further, the refrigerant circuit  12 A ( 12 B) is configured such that the refrigerant flows in an order of the carbon dioxide sublimator  5 A ( 5 B) and the water vapor condenser  4 A ( 4 B) as similar to the carbon dioxide recovery device  50 B. As the refrigerant, the cold heat formed by regasification of liquefied fuel (one example of fluid) is used as similar to the carbon dioxide recovery devices  50 A,  50 B, and  100 A. 
     Function of the refrigerant, the water vapor condenser  4 A ( 4 B), and the carbon dioxide sublimator  5 A ( 5 B) in the carbon dioxide recovery device  100 B having the above-mentioned configuration is explained below. 
     The refrigerant passes through the refrigerant circuit  12 A ( 12 B) to firstly cool inside the carbon dioxide sublimator  5 A ( 5 B) to the temperature appropriate for sublimation (solidification) of the carbon dioxide by the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B) so that the carbon dioxide in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (solidified). This is similar to the carbon dioxide recovery devices  50 A,  50 B, and  100 A. Herein, the temperature appropriate for sublimation (solidification) of the carbon dioxide is about minus 85 degrees centigrade or below when the combustion exhaust gas from an iron manufacturing plant or a cement plant is used as the to-be-separated gas, about minus 96 degrees centigrade or below when the combustion exhaust gas from a power plant is used as the to-be-separated gas, and about minus 140 degrees centigrade or below when the atmosphere is used as the to-be-separated gas as mentioned above. 
     When sublimation (solidification) of the carbon dioxide is performed in the carbon dioxide sublimator  5 A ( 5 B), the carbon dioxide sublimator  5 A ( 5 B) is depressurized to be under negative pressure. Thereby, the carbon dioxide sublimator  5 A ( 5 B) functions as a pump to perform suction of the water vapor and the carbon dioxide that have been diffused from the separation device  80 . This suction generates flow of the water vapor and the carbon dioxide toward the water vapor condenser  4 A ( 4 B) and the carbon dioxide sublimator  5 A ( 5 B). 
     Further, in association with decompression of the carbon dioxide sublimator  5 A ( 5 B), the separation device  80  connected in series is depressurized to about 4 kPa, which is similar to the carbon dioxide recovery device  100 A. 
     After cooling inside the carbon dioxide sublimator  5 A ( 5 B), the refrigerant flows to the water vapor condenser  4 A ( 4 B) to cool inside the water vapor condenser  4 A ( 4 B) by the heat exchanger  41 A ( 41 B) of the water vapor sublimator  4 A ( 4 B). The temperature of the refrigerant increases by heat exchanging in the heat exchanger  51 A ( 51 B) of the carbon dioxide sublimator  5 A ( 5 B), and thus the inside of the water vapor condenser  4 A ( 4 B) is cooled down to about 1 degree centigrade. 
     Since the water vapor condenser  4 A ( 4 B) is about 1 degree centigrade, the carbon dioxide and the water vapor which are sucked by the negative pressure generated in the carbon dioxide sublimator  5 A ( 5 B) and discharged from the separation device  80  (the transmission side  802 ) are made to flow into the water vapor condenser  4 A ( 4 B) to be cooled down to about 20 degrees centigrade. Thereby, the water vapor is condensed to become water. The water is stored on a bottom part of the water vapor condenser  4 A ( 4 B), and the thus stored water is discharged through the drain  43 A ( 43 B) by opening the open-close valve  15 A ( 15 B). 
     The carbon dioxide that has flown with the water vapor in the water vapor condenser  4 A ( 4 B) remains as gaseous body in a temperature about 20 degrees centigrade, and accordingly, the carbon dioxide is sucked by the carbon dioxide sublimator  5 A ( 5 B) so that the carbon dioxide passes through the second transfer pipe L 16 A (L 16 B) and flows in the carbon dioxide sublimator  5 A ( 5 B). Then, the carbon dioxide having flown in the carbon dioxide sublimator  5 A ( 5 B) is sublimated (solidified) as mentioned above. 
     As explained above, the carbon dioxide recovery device  100 A according to the fourth embodiment and the carbon dioxide recovery device  100 B according to its modified example are configured such that the separation device  80  is provided with the permeable membrane  803  to selectively transmit carbon dioxide, and the permeable membrane  803  transmits the carbon dioxide included in the to-be-separated gas (such as combustion exhaust gas) that has been supplied to the separation device  80  to separate the carbon dioxide from the to-be-separated gas (such as the combustion exhaust gas). The carbon dioxide sublimators  5 A,  5 B are connected to the transmission side  802  of the permeable membrane  803  of the separation device  80 . 
     According to the above-mentioned carbon dioxide recovery devices  100 A,  100 B, the separation device  80  is provided with the permeable membrane (for example, an inorganic membrane such as a zeolite membrane and an organic membrane such as a molecular gate membrane)  803  to selectively transmit the carbon dioxide, and thus the carbon dioxide included in the to-be-separated gas (such as the combustion exhaust gas) that has been supplied to the separation device  80  is separated to the transmission side  802  of the permeable membrane  803 . Then, the carbon dioxide sublimators  5 A,  5 B are connected to the transmission side  802  of the permeable membrane  803  of the separation device  80 , and accordingly, the carbon dioxide separated from the to-be-separated gas is cooled by the refrigerant and sublimated (solidified) in the carbon dioxide sublimators  5 A,  5 B. The carbon dioxide sublimators  5 A,  5 B are depressurized by this sublimation (solidification) to depressurize the transmission side  802  of the separation device  80  connected with the carbon dioxide sublimators  5 A,  5 B, so that separation of the carbon dioxide by the permeable membrane  803  is promoted. A pump or the like for decompression is not required, and thus no electric power is necessary, achieving energy conservation. Further, this energy conservation can achieve suppression of increase in electric power cost and achieve suppression of generation of further carbon dioxide for power generation. 
     In the carbon dioxide recovery devices  1 A,  1 B,  50 A,  50 B,  100 A, and  100 B explained above, after the carbon dioxide is sublimated (solidified) to obtain dry ice, an inside temperature of the carbon dioxide sublimator  5 A ( 5 B) is returned to a normal temperature to sublimate (gasify) the dry ice and the device recovers the dry ice from the take-out pipe  54 A ( 54 B). As above, in recovering the carbon dioxide as gaseous body, for example, if a chemical plant is located adjacent to the carbon dioxide recovery devices  1 A,  1 B,  50 A,  50 B,  100 A, and  100 B, the carbon dioxide recovered as the gaseous body can be supplied to the chemical plant through a pipe, so that the carbon dioxide can be efficiently used. 
     Alternatively, in the carbon dioxide recovery devices  1 A,  1 B,  50 A,  50 B,  100 A, and  100 B, the carbon dioxide may be recovered as liquid body instead of gaseous body. In considering transportation after recovery of the carbon dioxide, it is better to recover as the liquid body since transportation by lorries or trucks is made more easily. Further, in the carbon dioxide sublimator  5 A ( 5 B), liquefication of the dry ice rather than gasification can achieve a reduction in an increase range of a temperature inside the carbon dioxide sublimator  5 A ( 5 B). Therefore, in order to sublimate (solidify) the carbon dioxide again after taking out the carbon dioxide from the carbon dioxide sublimator  5 A ( 5 B), the cold heat used as the refrigerant for cooling the carbon dioxide sublimators  5 A,  5 B can be saved. 
       FIG.  7    is a graph showing a state of the carbon dioxide. According to this graph, a region surrounded by a melting line ML and a vaporization line VL is a region obtained by a liquid phase of the carbon dioxide (hereinafter, referred as liquefied carbon dioxide). Accordingly, in order to recover the liquefied carbon dioxide from the carbon dioxide sublimator  5 A ( 5 B), the temperature of the dry ice needs to be increased at least to a triple point TP where the melting line ML, the vaporization line VL, and a sublimation line SL are crossed. However, before the temperature reaches the triple point TP, a certain amount of carbon dioxide gets gasified, and the thus gasified carbon dioxide cannot be liquefied depending on changes in the temperature under an isochoric state, resulting in loss of the carbon dioxide. To address this, the carbon dioxide sublimator  5 A ( 5 B) is preferably controlled as mentioned below in order to make this loss as less as possible. 
     After performing sublimation (solidification) of the carbon dioxide in the carbon dioxide sublimators  5 A,  5 B, heat pumps  52 A,  52 B (one example of a heating medium) of the carbon dioxide sublimators  5 A,  5 B are set at a temperature of the triple point or higher of the carbon dioxide. Thereby, inside the carbon dioxide sublimators  5 A,  5 B that have been cooled for sublimating (solidifying) the carbon dioxide is heated to liquefy the carbon dioxide which is in a form of the dry ice. 
     Then, heating by the heat pumps  52 A,  52 B are halted at the time when the temperature of the obtained liquefied carbon dioxide is in a range of minus 56.6 degrees centigrade to minus 50 degrees centigrade inclusive so that the liquefied carbon dioxide is collected with less loss. 
     The applicant has confirmed from experiments that the liquefied carbon dioxide can be recovered with less loss when the temperature of the liquefied carbon dioxide is in the range of about minus 50 degrees centigrade to 10 degrees centigrade. However, once the temperature of the carbon dioxide has reached the triple point, there is a possibility that the temperature suddenly goes higher from the triple point, resulting in an increase in the loss In response to this, heating is stopped at the time when the temperature is in the range of minus 56.6 degrees centigrade to minus 50 degrees centigrade inclusive so that the temperature of the liquefied carbon dioxide can be in the above-mentioned range of about minus 50 degrees centigrade to 10 degrees centigrade. 
     The timing of stopping heating by the heat pumps  52 A.  52 B may be the time when a pressure inside the carbon dioxide sublimators  5 A,  5 B becomes 518 kPa or more and 800 kPa or less. This pressure range corresponds to a range in the graph of  FIG.  7    on the vaporization line VL in a range of minus 56.6 degrees centigrade to minus 50 degrees centigrade inclusive. 
     Further, it is preferable to start heating by the heat pumps  52 A,  52 B for recovering the liquefied carbon dioxide from the carbon dioxide sublimators  5 A,  5 B after the carbon dioxide is sublimated (solidified) until a ratio of a volume of the dry ice to a volume of the carbon dioxide sublimators  5 A,  5 B (hereinafter, referred simply as a volume ratio) is in a range of 0.1 to 0.3 inclusive. Thus, the liquefied carbon dioxide can be recovered with less loss. 
       FIG.  8    is a chart indicating a mass ratio of recoverable liquefied carbon dioxide and a mass ratio of gasified carbon dioxide (namely, a mass ratio of carbon dioxide that cannot be recovered and results in loss) with respect to a mass of the dry ice for each predetermined volume ratio in a case that the liquefied carbon dioxide is recovered under a condition (hereinafter, referred as a recovery condition) that the temperature of the liquefied carbon dioxide is minus 50 degrees centigrade and a pressure inside the carbon dioxide sublimators  5 A,  5 B is about 530 kPa. 
     For example, when the liquefied carbon dioxide is recovered under the above-mentioned recovery condition with a volume ratio of 0.12, the mass ratio of the recoverable liquefied carbon dioxide is 0.938 and the mass ratio of the gasified carbon dioxide is 0.062. Increase in the volume ratio from 0.12 causes increase in the mass ratio of the recoverable liquefied carbon dioxide, and accordingly, the loss is reduced. Then, when the liquefied carbon dioxide is recovered under the above recovery condition with the volume ratio of 0.3, the mass ratio of the recoverable liquefied carbon dioxide is 0.979 and the mass ratio of the gasified carbon dioxide is 0.021. In other words, after the carbon dioxide is sublimated (solidified) until the volume ratio is in the range of 0.1 to 0.3 inclusive, 90% or more than the mass of the dry ice can be recovered as the liquefied carbon dioxide as mentioned above. 
     Herein, the applicant has confirmed from experiments that the volume ratio less than 0.1 results in the mass ratio of the recoverable liquefied carbon dioxide as less than 0.9. The mass ratio less than 0.9 causes an increase in the loss by that amount, which is not preferable. Further, the applicant has confirmed from experiments that the volume ratio more than 0.3 results in a saturated state of the mass ratio of the recoverable liquefied carbon dioxide. If the carbon dioxide is to be sublimated (solidified) until the volume ratio becomes 0.3 or more, only the time required for sublimation (solidification) is increased while the mass ratio of the recoverable liquefied carbon dioxide is not increased, resulting in degradation in a recovery efficiency in the carbon dioxide, which is not preferable. 
     As mentioned above, in order to recover the liquefied carbon dioxide obtained in the carbon dioxide sublimators  5 A,  5 B, the open-close valves  17 A ( 17 B) of the take-out pipe  54 A ( 54 B) may be opened. Heating inside the carbon dioxide sublimators  5 A,  5 B causes increase in the pressure inside the carbon dioxide sublimators  5 A,  5 B, so that valve-opening of the open-close valves  17 A,  17 B leads to discharge of the liquefied carbon dioxide from the take-out pipe  54 A ( 54 B) by push-out of the pressure inside the carbon dioxide sublimators  5 A,  5 B. 
     Fifth Embodiment 
     Further, when the liquefied carbon dioxide is to be recovered from the carbon dioxide sublimators  5 A,  5 B, like a carbon dioxide recovery device  1 C according to a fifth embodiment shown in  FIG.  9   , for example, the carbon dioxide sublimators  5 A,  5 B may be connected with gas-liquid separators  91 A,  91 B, respectively. These gas-liquid separators  91 A,  91 B are, for example, devices configured to separate liquid and gas by use of a centrifugal force or surface tension and the like. The carbon dioxide recovery device  1 C shown in  FIG.  9    has the same configuration as the carbon dioxide recovery device  1 A in  FIG.  1    except the configuration that the gas-liquid separators  91 A,  91 B are connected to the carbon dioxide sublimators  5 A,  5 B. However, the configuration in  FIG.  9    is only an example, and the gas-liquid separators  91 A,  91 B may be connected to the carbon dioxide sublimators  5 A,  5 B of any one of the carbon dioxide recovery devices  1 B,  50 A,  50 B,  100 A, and  100 B. 
     When a gaseous body such as nitrogen that remains in a gas state at minus 162 degrees centigrade (the temperature of the above-mentioned cold heat) flows into the carbon dioxide sublimators  5 A,  5 B (hereinafter, explanation is made with nitrogen as one example), nitrogen remains in the gas state even under the temperature and pressure condition for receiving the liquefied carbon dioxide from the carbon dioxide sublimators  5 A  5 B, so that the nitrogen could be discharged with the liquefied carbon dioxide when the liquefied carbon dioxide is to be output through the take-out pipe  54 A ( 54 B) of the carbon dioxide sublimators  5 A,  5 B. To address this, the gas-liquid separators  91 A,  91 B are connected to the carbon dioxide sublimators  5 A,  5 B so that the liquefied carbon dioxide and the nitrogen flow into the gas-liquid separators  91 A,  91 B from the take-out pipe  54 A ( 54 B), and thus the liquefied carbon dioxide and the nitrogen can be separated in the gas-liquid separators  91 A,  91 B. 
     To the gas-liquid separators  91 A,  91 B, gas discharge pipes  94 A,  94 B provided with open-close valves  92 A,  92 B are connected, and by opening the open-close valves  92 A,  92 B, the separated nitrogen can be discharged from the gas discharge pipes  94 A,  94 B. Further, to the gas-liquid separators  91 A,  91 B, liquefied-carbon-dioxide discharge pipes  95 A,  95 B provided with open-close valves  93 A,  93 B are connected, and by opening the open-close valves  93 A,  93 B, the liquefied carbon dioxide that has been separated from the nitrogen can be taken out from the liquefied-carbon-dioxide discharge pipes  95 A,  95 B. 
     Sixth Embodiment 
     Furthermore, when carbon dioxide is to be recovered in a form of liquid, the carbon dioxide sublimators  5 A,  5 B may be connected with solid-liquid separators  96 A,  96 B as a carbon dioxide recovery device  1 D according to a sixth embodiment shown in  FIG.  10   . These solid-liquid separators  96 A, % B are, for example, devices configured to separate liquid and solid by use of a sedimentation method, a centrifugation method, a compression method, a filtration method, and others. Herein, the carbon dioxide recovery device  1 D shown in  FIG.  10    has the same configuration as the carbon dioxide recovery device  1 A shown in  FIG.  1    except the configuration that the carbon dioxide sublimators  5 A,  5 B are connected with the solid-liquid separators  96 A,  96 B, respectively. However, the configuration shown in  FIG.  10    is only one illustration, and the solid-liquid separators  96 A,  96 B may be connected to the carbon dioxide sublimators  5 A,  5 B of the respective carbon dioxide recovery devices  1 B,  50 A,  50 B,  100 A, and  100 B. 
     When moisture is mixed in the carbon dioxide sublimators  5 A,  5 B in a process of obtaining liquefied carbon dioxide from dry ice, the moisture is solidified to turn ice depending on a temperature condition in recovering the liquefied carbon dioxide from the carbon dioxide sublimators  5 A,  5 B. This ice could be discharged with the liquefied carbon dioxide when the liquefied carbon dioxide is to be output from the take-out pipe  54 A ( 54 B) of the carbon dioxide sublimators  5 A,  5 B. To address this, the solid-liquid separators  96 A,  96 B are connected to the carbon dioxide sublimators  5 A,  5 B, respectively, such that the liquefied carbon dioxide and the ice flow into the solid-liquid separators  96 A,  96 B from the take-out pipe  54 A ( 54 B), and thereby the liquefied carbon dioxide and the ice can be separated in the solid-liquid separators  96 A, % B. 
     The solid-liquid separators % A,  96 B are connected with liquefied-carbon-dioxide discharge pipes  98 A,  98 B provided with open-close valves  97 A,  97 B, respectively, and the liquefied carbon dioxide that has been separated from the ice can be taken out from the liquefied-carbon-dioxide discharge pipes  98 A,  98 B by opening the open-close valves  97 A,  97 B. 
     Further, the above explanation has been made with a situation where the carbon dioxide sublimators  5 A,  5 B are connected with either the gas-liquid separators  91 A,  91 B or the solid-liquid separators  96 A,  96 B, but the carbon dioxide sublimators  5 A,  5 B may be connected with the gas-liquid separators  91 A,  91 B and the solid-liquid separators  96 A,  96 B in this order in series. 
     Configuration of Carbon Dioxide Sublimator 
     The carbon dioxide sublimators  5 A,  5 B used for the above-mentioned carbon dioxide recovery devices  1 A,  1 B,  1 C,  1 D,  50 A,  50 B,  100 A, and  100 B may have a configuration as shown in  FIG.  13    and  FIG.  14   . In  FIG.  13   ,  FIG.  14   , and the following explanation, indication of the carbon dioxide sublimator is simply made as the carbon dioxide sublimator  5 . 
     The carbon dioxide sublimator  5  is configured by coupling a sublimation chamber  55  for sublimating (solidifying) carbon dioxide and a recovery chamber  56  for recovering a dry ice  90  as the sublimated (solidified) carbon dioxide. 
     The sublimation chamber  55  is connected with a transfer pipe L 21  to introduce the carbon dioxide to inside the sublimation chamber  55  from the transfer pipe L 21 . Herein, this transfer pipe L 21  corresponds to any one of the second transfer pipes L 16 A, L 16 B in the carbon dioxide recovery device  1 A (see  FIG.  1   ), the branch transfer pipes L 161 A, L 161 B in the carbon dioxide recovery device  1 B (see  FIG.  2   ), the transfer pipes L 15 A, L 15 B in the carbon dioxide recovery device  50 A (see  FIG.  3   ), the second transfer pipes L 16 A, L 16 B in the carbon dioxide recovery device  50 B (see  FIG.  4   ), the branch transfer pipes L 151 A, L 151 B in the carbon dioxide recovery device  100 A (see  FIG.  5   ), the second transfer pipes L 16 A, L 16 B in the carbon dioxide recovery device  100 B (see  FIG.  6   ), the second transfer pipes L 16 A, L 16 B in the carbon dioxide recovery device  1 C (see  FIG.  9   ), and the second transfer pipes L 16 A, L 16 B in the carbon dioxide recovery device  1 D (see  FIG.  10   ). 
     The sublimation chamber  55  is arranged inside with a heat exchanger  51  connected to a refrigerant circuit  12 . Thus, inside the sublimation chamber  55  can be cooled down to a temperature appropriate for sublimation (solidification) of the carbon dioxide. Herein, the temperature appropriate for sublimation (solidification) of the carbon dioxide is, as mentioned above, about minus 85 degrees centigrade or below when the combustion exhaust gas from an iron manufacturing plant or a cement plant is used as the to-be-separated gas, about minus 96 degrees centigrade or below when the combustion exhaust gas from the power plant is used as the to-be-separated gas, and about minus 140 degrees centigrade or below when the atmosphere is used as the to-be-separated gas. Further, an outer circumferential surface of the heat exchanger  51  is an attachment surface  57  (one example of an attachment portion) to which the dry ice  90  sublimated (solidified) in the sublimation chamber  55  is to be attached. 
     Further, the attachment surface  57  is connected with a heater  58 . This heater  58  is for example, a cartridge heater. Operation of the heater  58  allows local heating of the attachment surface  57  of the heat exchanger  51 . By heating the attachment surface  57 , a surface contacted with the attachment surface  57  of the dry ice  90  which is attached to the attachment surface  57  can be sublimated (gasified). Thus, the dry ice  90  can be fallen off from the attachment surface  57 . 
     The sublimation chamber  55  is provided with a first opening port  552  on an end portion on a side of the recovery chamber  56 . Further, the sublimation chamber  55  is provided with a slant portion  551  constituting a downward slope toward the first opening port  552  between the heat exchanger  51  and the first opening port  552 . 
     The recovery chamber  56  is provided with a second opening port  561  on an end portion on a side of the sublimation chamber  55 . Then, the first opening port  552  of the sublimation chamber  55  and the second opening port  561  of the recovery chamber  56  are connected via a shut-off member  59 . When the shut-off member  59  is brought in a closed state, inside the sublimation chamber  55  and inside the recovery chamber  56  are blocked ( FIG.  13   ), and when the shut-off member  59  is brought in an open state, inside the sublimation chamber  55  and inside the recovery chamber  56  are in a communicated state ( FIG.  14   ). The recovery chamber  56  is located below the attachment surface  57 , so that once inside the sublimation chamber  55  and inside the recovery chamber  56  are communicated, the recovery chamber  56  can receive the dry ice  90  which is falling off the attachment surface  57 . Further, the recovery chamber  56  is connected with a take-out pipe  54 . This take-out pipe  54  is identical with the above-mentioned take-out pipe  54 A ( 54 B). 
     When the carbon dioxide sublimator  5  having the above-mentioned configuration is used, recovery of the carbon dioxide is performed as below. 
     Firstly, inside the sublimation chamber  55  is cooled by the heat exchanger  51  (the refrigerant flowing in the refrigerant circuit  12 ) to a temperature appropriate for sublimation (solidification) of the carbon dioxide. At this time, the shut-off member  59  is made to be in the closed state. While inside the sublimation chamber  55  is being cooled down, the carbon dioxide is introduced in the sublimation chamber  55  from the transfer pipe L 21 . The carbon dioxide introduced in the sublimation chamber  55  is sublimated (solidified) to be attached to the attachment surface  57  as shown in  FIG.  13   . 
     The heater  58  is operated while the dry ice  90  remains attached to the attachment surface  57 , and thus the attachment surface  57  is heated to sublimate (gasify) the surface of the dry ice  90  to which the attachment surface  57  is attached. By this sublimation (gasification), the dry ice  90  attached to the attachment surface  57  is fallen off toward the slant portion  551  as indicated with an arrow A 11  in  FIG.  14    by the gravity. Then, the dry ice  90  having fallen to the slant portion  551  slides on the slant portion  551  toward the first opening port  552  as indicated with an arrow A 12  by gravity. At this time, the shut-off member  59  is in the open state so that the dry ice  90  passes through the second opening port  561  from the first opening port  552  and then accommodated in the recovery chamber  56 . The dry ice  90  accommodated in the recovery chamber  56  is sublimated (gasified) or liquefied and recovered from the take-out pipe  54 . Herein, a casing of the recovery chamber  56  may be provided with a door or the like which is accessible to inside the recovery chamber  56  so that the carbon dioxide is recovered through that door in a form of solid. 
     Sublimation (gasification) of a contact surface of the dry ice  90  with the attachment surface  57  is enough for making the dry ice  90  fall from the attachment surface  57 , and thus heating of the heater  58  may be made in a short time. Accordingly, the temperature of the sublimation chamber  55  that has been cooled to the temperature appropriate for sublimation (solidification) of the carbon dioxide does not have to be increased until the dry ice  90  is gasified or liquefied. In other words, a temperature changing range of the sublimation chamber  55  in recovering the dry ice  90  can be made small, and thus it is possible to suppress thermal impact applying to the sublimation chamber  55 . Further, the thus small temperature changing range achieves suppression in loss of the cold heat and time which are required for cooling the sublimation chamber  55  in performing sublimation (solidification) of the carbon dioxide again in the sublimation chamber  55  after recovering the dry ice  90 . 
     Herein, in each of the above-mentioned carbon dioxide recovery devices  1 A,  1 B,  1 C,  1 D,  50 A,  50 B,  100 A, and  100 B, the two carbon dioxide sublimators  5 A,  5 B are used (see  FIG.  1   .  FIG.  2   ,  FIG.  3   ,  FIG.  4   ,  FIG.  5   ,  FIG.  6   ,  FIG.  9   , and  FIG.  10   ). This is because while the one carbon dioxide sublimator  5 A or  5 B recovers the carbon dioxide that has been completed with sublimation (solidification), the other carbon dioxide sublimator  5 A or  5 B is made to perform sublimation (solidification) of the carbon dioxide, and thereby, recovery efficiency of the carbon dioxide can be improved. 
     However, if the carbon dioxide sublimator  5  shown in  FIG.  13    and  FIG.  14    is to be used, two sublimators do not necessarily have to be provided. As mentioned above, the carbon dioxide sublimator  5  can reduce the temperature changing range of the sublimation chamber  55  in recovering the dry ice  90 , so that the subsequent sublimation (solidification) can be performed in a short time after the dry ice  90  is made to fall off the attachment surface  57 , and thus the carbon dioxide can be efficiently recovered without using two sublimators. 
     The above-mentioned carbon dioxide recovery devices  1 A,  1 B,  1 C,  1 D,  50 A,  50 B,  100 A, and  100 B are only illustrations and have no any limitation to the present invention. Accordingly, the present invention can naturally be made with any improvements or modifications without departing from scope of the invention. For example, the features that the temperature of the water vapor condenser  4 A ( 4 B) is set to 1 degree centigrade, the carbon dioxide sublimator  5 A ( 5 B) is set at a temperature appropriate for sublimation (solidification) of the carbon dioxide, and the pressure of the separation device  70 A ( 70 B) is decompressed to about 4 kPa are only illustrations and the invention is not limited to those. For example, the temperature of the carbon dioxide sublimator  5 A ( 5 B) may be lower so that the carbon dioxide is made to turn dry ice more rapidly. However, if the temperature is lowered too much, there is contrarily a possibility of degradation in the recovery efficiency of the carbon dioxide since it is considered that when the carbon dioxide is to be recovered from the carbon dioxide sublimator  5 A ( 5 B), sublimation (gasification) of the dry ice takes time and the pressure of the regeneration tower  3  becomes too low, so that the adsorbent is in a coexistence state of liquid and solid, resulting in degradation in efficiency of diffusing the carbon dioxide. Accordingly, the temperature of the carbon dioxide sublimator  5 A ( 5 B) is appropriately adjusted in accordance with the recovery efficiency of the carbon dioxide. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1 A Carbon dioxide recovery device 
               60  Separation device 
               5 A Carbon dioxide sublimator 
               5 B Carbon dioxide sublimator 
               12 A Refrigerant circuit 
               12 B Refrigerant circuit