Carbon dioxide separation and recovery system

Abstract

To provide a carbon dioxide separation and recovery system which can maximize a carbon dioxide separation and recovery amount per unit coolant flow rate.SOLUTION: A carbon dioxide separation and recovery system 1 has a carbon dioxide solidification unit 10 for solidifying carbon dioxide by heat exchange between exhaust gas containing the carbon dioxide and a coolant, a coolant supply path 31 which is connected to the carbon dioxide solidification unit 10 and supplies the coolant to the carbon dioxide solidification unit 10, and a coolant discharge path 32 which is connected to the carbon dioxide solidification unit 10, and discharges the coolant from the carbon dioxide solidification unit 10, wherein the coolant flowing in the coolant supply path 31 is liquid, and all the coolants flowing in the coolant discharge path 32 are gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbon dioxide separation and capture system that separates and captures carbon dioxide from combustion exhaust gas, and more particularly to a carbon dioxide separation and capture system that solidifies, separates, and captures carbon dioxide by heat exchange between the combustion exhaust gas and a refrigerant. [Background technology]

[0002] Generally, most of the carbon dioxide released into the atmosphere is contained in exhaust gas from the combustion of fossil fuels. Because carbon dioxide has an impact on global warming, there are studies being conducted on reducing carbon dioxide emissions or utilizing it. However, the concentration of carbon dioxide contained in exhaust gas is low, ranging from a few percent to a dozen percent, and separation of carbon dioxide from exhaust gas is essential for utilizing it.

[0003] Technologies for separating carbon dioxide from gases that contain carbon dioxide have long been used industrially, and well-known methods include those using hot potassium carbonate or amine-based absorption liquids, those using gas separation membranes, and the pressure swing adsorption (PSA) and temperature swing adsorption (TSA) methods that use adsorbents.

[0004] However, these separation technologies have only been used in cases where removing the carbon dioxide would increase the value of the remaining gas or where there are benefits to using the carbon dioxide, such as in enhanced oil recovery (EOR), and both methods consume large amounts of energy to separate the carbon dioxide. If fossil fuels are used to generate this energy, the effect of reducing carbon dioxide emissions will be small, and the amount of energy obtained from each fossil fuel will also decrease, making this economically unacceptable. Therefore, there is a demand for new energy-saving carbon dioxide separation technology that consumes as little energy as possible when separating carbon dioxide as a measure against global warming.

[0005] In this regard, Patent Document 1 discloses a technique for solidifying carbon dioxide in exhaust gas by heat exchange between the exhaust gas after solidifying and removing moisture and LNG, thereby liquefying dry ice. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-317302 A Summary of the Invention [Problem to be solved by the invention]

[0007] In order to maximize the heat exchange efficiency in a system that uses the cold energy of LNG to solidify CO2, it is desirable to make the solidification temperature of CO2 in the exhaust gas equivalent to the boiling point of LNG, thereby using the large latent heat of vaporization of LNG to provide the large latent heat of solidification of CO2. However, the technology described in Patent Document 1 does not express or suggest such a technical idea, so there is still room for improvement in efficient CO2 solidification.

[0008] The present invention has been made to solve such problems, and has an object to provide a carbon dioxide separation and capture system that can maximize the amount of carbon dioxide separated and captured per unit refrigerant flow rate. [Means for solving the problem]

[0009] (1) The carbon dioxide separation and capture system according to the present invention comprises: a carbon dioxide solidifier that solidifies the carbon dioxide by heat exchange between an exhaust gas containing carbon dioxide and a refrigerant; a refrigerant supply passage connected to the carbon dioxide solidifier and supplying the refrigerant to the carbon dioxide solidifier; a refrigerant discharge passage connected to the carbon dioxide solidifier and discharging the refrigerant from the carbon dioxide solidifier, The coolant flowing through the coolant supply passage is liquid, and the coolant flowing through the coolant discharge passage is entirely gas.

[0010] (2) In addition, in the above (1), a refrigerant composition analyzer for analyzing the composition of the refrigerant; a refrigerant pressure regulator for adjusting the pressure of the refrigerant; A control device for controlling the refrigerant pressure regulator, The control device is characterized in that it controls the refrigerant pressure regulator so as to evaporate the entire amount of the liquid refrigerant inside the carbon dioxide solidification device based on the analysis result of the refrigerant composition analyzer.

[0011] (3) In addition, in the above (2), a refrigerant flow rate regulator that regulates the flow rate of the refrigerant; A control device for controlling the refrigerant flow rate regulator, The control device is characterized in that it controls the refrigerant pressure regulator and the refrigerant flow rate regulator so that the amount of cold energy required for solidifying the carbon dioxide is supplied to the carbon dioxide solidifier based on the analysis result of the refrigerant composition analyzer.

[0012] (4) In addition, in the above (1), an exhaust gas composition analyzer for analyzing the composition of the exhaust gas; an exhaust gas pressure regulator that adjusts the pressure of the exhaust gas; A control device for controlling the exhaust gas pressure regulator, The control device is characterized in that it controls the exhaust gas pressure regulator so as to solidify the carbon dioxide contained in the exhaust gas inside the carbon dioxide solidification device based on the analysis results of the exhaust gas composition analyzer.

[0013] (5) In addition, in the above (4), An exhaust gas flow regulator that adjusts the flow rate of exhaust gas, A control device for controlling the exhaust gas flow regulator, The control device is characterized in that it controls the exhaust gas pressure regulator and the exhaust gas flow rate regulator so that the amount of heat required for evaporation of the refrigerant is supplied to the carbon dioxide solidifier based on the analysis results of the exhaust gas composition analyzer. Effect of the Invention

[0014] In the present invention, the latent heat of solidification of carbon dioxide is met by the latent heat of vaporization of the refrigerant, so that the amount of carbon dioxide separated and recovered per unit flow rate of the refrigerant can be maximized. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a carbon dioxide separation and capture system according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic diagram showing a carbon dioxide separation and capture system according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a schematic diagram showing a carbon dioxide separation and capture system according to a third embodiment of the present invention. [Figure 4] FIG. 11 is a schematic diagram showing a carbon dioxide separation and capture system according to a fourth embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic diagram showing a carbon dioxide separation and capture system according to a fifth embodiment of the present invention. [Figure 6] FIG. 13 is a schematic diagram showing a carbon dioxide separation and capture system according to a sixth embodiment of the present invention. [Figure 7] FIG. 13 is a schematic diagram showing a carbon dioxide separation and capture system according to a seventh embodiment of the present invention. [Figure 8] FIG. 13 is a schematic diagram showing a carbon dioxide separation and capture system according to an eighth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] [Embodiment 1] The structure and function of the carbon dioxide separation and capture system 1 according to this embodiment will be described. As shown in FIG. 1, the carbon dioxide separation and capture system 1 of this embodiment includes a carbon dioxide solidifier 10, a refrigerant inlet pipe 31 that supplies a refrigerant to the carbon dioxide solidifier 10, a refrigerant outlet pipe 32 that discharges the refrigerant from the carbon dioxide solidifier 10, an exhaust gas inlet pipe 33 that supplies exhaust gas to the carbon dioxide solidifier 10, a dry ice outlet pipe 34 that discharges carbon dioxide solidified in the carbon dioxide solidifier 10, an excess gas outlet pipe 35 that discharges excess gases such as nitrogen and oxygen that were not solidified in the carbon dioxide solidifier 10, a refrigerant composition analyzer 41 that analyzes the composition of the refrigerant, a refrigerant pressure detector 42 that detects the pressure of the refrigerant, a refrigerant pressure regulating valve 43 that regulates the pressure of the refrigerant, and a control device 20 that controls the refrigerant pressure regulating valve 43.

[0018] The carbon dioxide solidifier 10 is a scraped surface heat exchanger, and receives LNG as a liquid refrigerant from a connected refrigerant inlet pipe 31. The carbon dioxide solidifier 10 also receives exhaust gas containing carbon dioxide from a connected exhaust gas inlet pipe 33.

[0019] Inside the carbon dioxide solidifier 10, heat exchange takes place between the LNG and the exhaust gas via a heat transfer tube (not shown), whereby carbon dioxide solidifies on the exhaust gas side surface of the heat transfer tube to produce dry ice. The produced dry ice is scraped off by a scraping mechanism (not shown) and falls in the form of powder or lumps inside the carbon dioxide solidifier 10. The fallen dry ice is discharged from the dry ice outlet pipe 34.

[0020] Of the exhaust gas components, those that do not solidify (nitrogen and oxygen) are cooled by heat exchange with the LNG, and are discharged from an excess gas outlet pipe 35 connected to the carbon dioxide solidifier 10 .

[0021] The liquid LNG that has exchanged heat with the exhaust gas inside the carbon dioxide solidifier 10 is entirely evaporated and becomes gaseous natural gas (hereinafter, referred to as NG). Therefore, the large latent heat of vaporization of LNG can be used to solidify CO2.

[0022] The refrigerant composition analyzer 41 is a commonly used sampling facility that diverts a portion of the LNG flowing through the refrigerant inlet pipe 31, evaporates the LNG by heat exchange with an external heat source, and analyzes the components by gas chromatography. The refrigerant composition analyzer 41 transmits the analysis results to the control device 20, which will be described later.

[0023] The refrigerant pressure detector 42 is a commonly used pressure gauge with a transmitter, which detects the pressure of the NG flowing through the refrigerant outlet pipe 32 and transmits a signal corresponding to the pressure to the control device 20, which will be described later.

[0024] The refrigerant pressure regulating valve 43 is a commonly used globe type pressure regulating valve, and regulates the pressure of the NG flowing through the refrigerant outlet pipe 32 by changing the opening degree of the valve.

[0025] The control device 20 is a processing device installed within a distributed control system (DCS) that is generally used in plant control, and controls the refrigerant pressure control valve 43 based on a signal received from a refrigerant composition analyzer 41 and a signal received from a refrigerant pressure detector 42. Further, the control device 20 has not only a function used for plant control but also a simulator function related to fluid properties.

[0026] Next, the operation of the carbon dioxide separation and capture system 1 according to this embodiment will be described. In this embodiment, it is assumed that information regarding the composition of the exhaust gas is known in advance and is constant, the pressure of the exhaust gas is also constant, and moisture has already been removed from the exhaust gas.

[0027] The control device 20 estimates the saturated vapor pressure of LNG based on the analysis results of the refrigerant composition analyzer 41. This provides information on the temperature at which LNG evaporates in relation to the pressure of LNG.

[0028] Here, since the composition and pressure of the exhaust gas are known and constant, the solidification temperature of carbon dioxide is also known and constant.

[0029] The control device 20 controls the refrigerant pressure regulating valve 43 so that the detection result of the refrigerant pressure detector 42 becomes the saturated vapor pressure of LNG at the solidification temperature of carbon dioxide in the exhaust gas.

[0030] As a result, inside the carbon dioxide solidifier 10, the LNG evaporates and removes an amount of heat equivalent to the latent heat of vaporization from the exhaust gas, thereby cooling the exhaust gas. When the temperature of the exhaust gas drops to the solidification temperature of the carbon dioxide in the exhaust gas, a large amount of heat is removed by the evaporation of the LNG, thereby solidifying the carbon dioxide.

[0031] According to the carbon dioxide separation and capture system 1 of this embodiment, the latent heat of vaporization of LNG can be used to solidify carbon dioxide, so that carbon dioxide can be solidified with a smaller LNG flow rate than when the sensible heat of LNG is used. This maximizes the amount of carbon dioxide separated and captured per unit refrigerant flow rate, and maximizes the amount of carbon dioxide solidified even when the LNG flow rate is limited.

[0032] In this embodiment, the carbon dioxide solidifier 10 has been described as a scraping-type heat exchanger, but the type is not limited to a scraping-type heat exchanger, and may be any type that can selectively solidify and separate carbon dioxide by heat exchange with a refrigerant and discharge it, such as a type in which dry ice is dropped using an air blower or knocker, or a type in which carbon dioxide is solidified and then pressurized to liquefy and discharged.

[0033] In addition, although the above description uses LNG as a refrigerant, the refrigerant of the present invention is not limited to this, and any refrigerant that is in a liquid or gaseous state depending on the pressure at a temperature that can solidify the carbon dioxide in the exhaust gas may be used, and single-component fluids such as nitrogen or hydrogen, or multi-component fluids based on fluorocarbons may also be selected as appropriate.

[0034] Further, the refrigerant composition analyzer 41 analyzes the LNG flowing through the refrigerant inlet pipe 31, but it may also analyze the NG flowing through the refrigerant outlet pipe 32. It is sufficient if the composition of the LNG refrigerant can be analyzed regardless of the phase.

[0035] In addition, the control device 20 is not limited to the form of a DCS, and may be a device having a PLC or other control function. In addition to implementing a process simulator inside the control device 20, the saturated vapor pressure may be estimated from the analysis results of the refrigerant composition analyzer 41 by referring to a relational equation or graph, etc. between the composition and the saturated vapor pressure, which are stored in advance.

[0036] [Embodiment 2] A second embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 101 of this embodiment has, in addition to the configuration of the carbon dioxide separation and capture system 1 of embodiment 1 shown in Figure 1, a refrigerant flow rate detector 141 and a refrigerant flow rate control valve 142 in the refrigerant inlet piping 31. Description of the configuration, functions, and actions similar to those of the first embodiment will be omitted.

[0037] The refrigerant flow rate detector 141 is a typical differential pressure type flow meter, and transmits a signal corresponding to the differential pressure to the control device 20, which converts it into a flow rate of the refrigerant. The refrigerant flow rate control valve 142 is a typical globe type flow rate control valve, and adjusts the flow rate of the refrigerant by changing the opening degree.

[0038] Next, the operation of the carbon dioxide separation and capture system 101 according to this embodiment will be described. The control device 20 controls the refrigerant pressure control valve 43 so that the LNG evaporates at the solidification temperature of the carbon dioxide in the exhaust gas, and also controls the refrigerant flow rate control valve 142 so that the refrigerant flow rate is such that the amount of cold energy corresponding to the total flow rate of the exhaust gas can be supplied to the carbon dioxide solidifier 10.

[0039] According to the carbon dioxide separation and capture system 101 of this embodiment, the total amount of latent heat of vaporization of LNG can be adjusted. As a result, even if the flow rate of the exhaust gas changes, the latent heat of vaporization corresponding to the latent heat of solidification of carbon dioxide can be supplied to the carbon dioxide solidifier 10, so that carbon dioxide can be solidified with a smaller LNG flow rate in accordance with demand.

[0040] In this embodiment, the refrigerant pressure control valve 43 is installed in the refrigerant outlet piping 32, but it is also possible to adopt a control method such as PC-FC cascade control, in which the refrigerant flow rate is adjusted so that the pressure in the refrigerant outlet piping 32 becomes a target pressure, without installing the refrigerant pressure control valve 43.

[0041] Incidentally, the provision of a refrigerant flow rate detector 141 and a refrigerant flow rate adjustment valve 142 in the refrigerant inlet pipe 31 and the control device 20 performing the control of this embodiment can also be applied to the fifth to eighth embodiments described later.

[0042] [Embodiment 3] A third embodiment of the present invention will be described with reference to Fig. 3. Descriptions of configurations, functions, and actions similar to those of the first embodiment will be omitted.

[0043] The carbon dioxide separation and capture system 201 according to this embodiment has an exhaust gas composition analyzer 241 , an exhaust gas pressure detector 242 , and an exhaust gas pressure control valve 243 in the exhaust gas inlet pipe 33 . In this embodiment, the pressure and composition of the LNG refrigerant are known and constant.

[0044] The exhaust gas composition analyzer 241 is a commonly used sampling device, which diverts a part of the exhaust gas flowing through the exhaust gas inlet pipe 33 and analyzes the components by gas chromatography. The exhaust gas composition analyzer 241 transmits the analysis results to the control device 20 .

[0045] The exhaust gas pressure detector 242 is a commonly used pressure gauge with a transmitter, which detects the pressure of the exhaust gas flowing through the exhaust gas inlet pipe 33 and transmits a signal corresponding to the pressure to the control device 20 .

[0046] The exhaust gas pressure control valve 243 is a commonly used butterfly type pressure control valve, and adjusts the pressure of the exhaust gas flowing through the exhaust gas inlet pipe 33 by changing the opening degree of the valve.

[0047] Next, the operation of the carbon dioxide separation and capture system 201 according to this embodiment will be described. Based on the analysis results of the exhaust gas composition analyzer 241, the control device 20 obtains information on the temperature at which carbon dioxide solidifies in relation to the pressure of the exhaust gas.

[0048] Here, since the composition and pressure of the LNG refrigerant are known and constant, the evaporation temperature of the LNG is also known and constant.

[0049] The control device 20 controls the exhaust gas pressure regulating valve 243 so that the detection result of the exhaust gas pressure detector 242 becomes the solidification pressure of carbon dioxide in the exhaust gas at the evaporation temperature of LNG.

[0050] As a result, inside the carbon dioxide solidifier 10, the pressure of the exhaust gas is adjusted to the solidification pressure of carbon dioxide at the evaporation temperature of the LNG, so that the large amount of latent heat of vaporization of the LNG provides the large amount of latent heat of solidification required to solidify the carbon dioxide, the entire amount of LNG evaporates, and the carbon dioxide in the exhaust gas solidifies.

[0051] According to the carbon dioxide separation and capture system 201 of this embodiment, by adjusting the pressure to a level at which carbon dioxide solidifies under conditions where the amount of cold received by the carbon dioxide solidifier 10 is maximized, the amount of carbon dioxide solidified can be maximized even with a limited LNG flow rate.

[0052] [Embodiment 4] A fourth embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 301 of this embodiment has the same configuration as the carbon dioxide separation and capture system 201 of embodiment 3 shown in Figure 3, and further includes an exhaust gas flow detector 341 and an exhaust gas flow control valve 342 in the exhaust gas inlet piping 33. Description of the same configuration as in the third embodiment will be omitted.

[0053] The exhaust gas flow detector 341 is a typical differential pressure flow meter, and transmits a signal corresponding to the differential pressure to the control device 20, which converts it into a flow rate of the exhaust gas. The exhaust gas flow rate control valve 342 is a typical butterfly type flow rate control valve, and adjusts the flow rate of the exhaust gas by changing the opening degree.

[0054] Next, the operation of the carbon dioxide separation and capture system 301 according to this embodiment will be described. The control device 20 adjusts the exhaust gas pressure to the carbon dioxide solidification pressure at the evaporation temperature of LNG, and also controls the exhaust gas flow control valve 243 so that the exhaust gas flow rate is such that a heat quantity equivalent to the total flow rate of LNG can be supplied to the carbon dioxide solidifier 10.

[0055] According to the carbon dioxide separation and capture system 301 of this embodiment, even if the flow rate of LNG changes and the amount of heat required to evaporate LNG in the carbon dioxide solidifier 10 changes, the latent heat of solidification of the carbon dioxide can be changed accordingly, so that the carbon dioxide can be solidified according to the LNG demand.

[0056] [Embodiment 5] A fifth embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 401 of this embodiment has the same configuration as the carbon dioxide separation and capture system 1 of embodiment 1 shown in Figure 1, but also has a low-temperature dehumidifier 450 provided downstream of the carbon dioxide solidifier 10 in the refrigerant flow path. Description of the configuration, functions, and actions similar to those of the first embodiment will be omitted.

[0057] The low-temperature dehumidifier 450 is a scraping-type heat exchanger that deposits ice on the exhaust gas side of the heat transfer tube by heat exchange between the exhaust gas upstream of the carbon dioxide solidifier 10 in the exhaust gas flow path and NG, which is the refrigerant evaporated in the carbon dioxide solidifier 10, and scrapes it off using a mechanical mechanism not shown.

[0058] According to the carbon dioxide separation and capture system 401 of this embodiment, the cold energy of the low-temperature NG at the outlet of the carbon dioxide solidifier 10 can be effectively utilized to dehumidify the exhaust gas, thereby reducing external energy.

[0059] In this embodiment, the low-temperature dehumidifier 450 has been described as a scraping-type heat exchanger, but the type is not limited to the scraping-type heat exchanger, and any type that can selectively solidify water by heat exchange with a refrigerant, such as a type in which ice is dropped using an air blower or a knocker, or a type in which water is solidified and then heated to liquefy and discharged, may be used.

[0060] Incidentally, providing the low-temperature dehumidifier 450 on the downstream side of the carbon dioxide solidifier 10 can also be applied to the first to fourth embodiments described above.

[0061] [Embodiment 6] A sixth embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 501 of this embodiment has the same configuration as the carbon dioxide separation and capture system 1 of embodiment 1 shown in FIG. 1, and further includes a gas-liquid mixer 560 as described in Japanese Patent No. 6,090,616 on the downstream side of the carbon dioxide solidifier 10 in the refrigerant flow path. Description of the configuration, functions, and actions similar to those of the first embodiment will be omitted.

[0062] The gas-liquid mixer 560 is a Venturi-type nozzle that causes LNG, which is a refrigerant, to flow through the main pipe, and takes in the NG evaporated by the carbon dioxide solidifier 10, mixes it with the LNG, and condenses it.

[0063] According to the carbon dioxide separation and capture system 501 of this embodiment, since NG can be condensed by the gas-liquid mixer 560, it is possible to reduce the power required for pressurizing NG.

[0064] Incidentally, providing the gas-liquid mixer 560 on the downstream side of the carbon dioxide solidifier 10 can also be applied to the first to fourth embodiments described above.

[0065] [Embodiment 7] A seventh embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 601 of this embodiment has the same configuration as the carbon dioxide separation and capture system 1 of embodiment 1 shown in Figure 1, and further includes a refrigerant condenser 670 provided downstream of the carbon dioxide solidifier 10 in the refrigerant flow path. Description of the configuration, functions, and actions similar to those of the first embodiment will be omitted.

[0066] The refrigerant condenser 670 is a shell-and-tube type heat exchanger, in which LNG as a refrigerant flows through the tube side, and NG evaporated by the carbon dioxide solidifier 10 flows through the shell side, thereby condensing the NG.

[0067] According to the carbon dioxide separation and capture system 601 of this embodiment, since NG can be condensed by the refrigerant condenser 670, the power required for pressurizing NG can be reduced.

[0068] Incidentally, providing the refrigerant condenser 670 on the downstream side of the carbon dioxide solidifier 10 can also be applied to the first to fourth embodiments described above.

[0069] [Embodiment 8] An eighth embodiment of the present invention will be described with reference to FIG. The carbon dioxide separation and capture system 701 of this embodiment has the same configuration as the carbon dioxide separation and capture system 1 of embodiment 1 shown in Figure 1, and further includes a refrigerant compressor 780 provided downstream of the carbon dioxide solidifier 10 in the refrigerant flow path. Description of the configuration, functions, and actions similar to those of the first embodiment will be omitted.

[0070] The refrigerant compressor 780 is a reciprocating compressor, and increases the pressure of the NG evaporated by the carbon dioxide solidifier 10 .

[0071] According to the carbon dioxide separation and capture system 701 of this embodiment, NG whose pressure is adjusted so that it evaporates at the carbon dioxide solidification temperature is compressed, so the compression ratio can be made smaller than when compressing low-pressure evaporated gas from an LNG tank, for example, and the power required to pressurize the NG can be reduced.

[0072] Incidentally, providing the refrigerant compressor 780 on the downstream side of the carbon dioxide solidifier 10 can also be applied to the first to fourth embodiments described above. [Industrial Applicability]

[0073] INDUSTRIAL APPLICABILITY The present invention can be used as a carbon dioxide separation and capture system that solidifies carbon dioxide by heat exchange between a combustion exhaust gas and a refrigerant, and separates and captures the carbon dioxide. [Explanation of symbols]

[0074] 1, 101, 201, 301, 401, 501, 601, 701 Carbon dioxide separation and capture system 10 Carbon dioxide solidifier 20 Control device 31 Refrigerant inlet pipe 32 Refrigerant outlet pipe 33 Exhaust gas inlet pipe 34 Dry ice outlet pipe 35 Excess gas outlet pipe 41 Refrigerant composition analyzer 42 Refrigerant pressure detector 43 Refrigerant pressure control valve 141 Refrigerant flow detector 142 Refrigerant flow control valve 241 Exhaust Gas Composition Analyzer 242 Exhaust gas pressure detector 243 Exhaust gas pressure control valve 341 Exhaust gas flow detector 342 Exhaust gas flow control valve 450 Low temperature dehumidifier 560 Gas-liquid mixer 670 Refrigerant Condenser 780 Refrigerant Compressor

Claims

1. a carbon dioxide solidifier that solidifies the carbon dioxide by heat exchange between an exhaust gas containing carbon dioxide and a refrigerant; a refrigerant supply passage connected to the carbon dioxide solidifier and supplying the refrigerant to the carbon dioxide solidifier; a refrigerant discharge passage connected to the carbon dioxide solidifier and discharging the refrigerant from the carbon dioxide solidifier, A carbon dioxide separation and capture system, characterized in that the refrigerant flowing through the refrigerant supply path is a liquid, and the refrigerant flowing through the refrigerant discharge path is all gas.

2. a refrigerant composition analyzer for analyzing the composition of the refrigerant; a refrigerant pressure regulator for adjusting the pressure of the refrigerant; A control device for controlling the refrigerant pressure regulator, The carbon dioxide separation and capture system according to claim 1, wherein the control device controls the refrigerant pressure regulator so as to evaporate all of the liquid refrigerant inside the carbon dioxide solidification device based on the analysis result of the refrigerant composition analyzer.

3. a refrigerant flow rate regulator that regulates the flow rate of the refrigerant; A control device for controlling the refrigerant flow rate regulator, The carbon dioxide separation and capture system according to claim 2, wherein the control device controls the refrigerant pressure regulator and the refrigerant flow rate regulator so that an amount of cold energy required for solidifying the carbon dioxide is supplied to the carbon dioxide solidifier based on an analysis result of the refrigerant composition analyzer.

4. an exhaust gas composition analyzer for analyzing the composition of the exhaust gas; an exhaust gas pressure regulator that adjusts the pressure of the exhaust gas; A control device for controlling the exhaust gas pressure regulator, The carbon dioxide separation and capture system according to claim 1, wherein the control device controls the exhaust gas pressure regulator so as to solidify the carbon dioxide contained in the exhaust gas inside the carbon dioxide solidification device based on the analysis results of the exhaust gas composition analyzer.

5. An exhaust gas flow regulator that adjusts the flow rate of exhaust gas, A control device for controlling the exhaust gas flow regulator, The carbon dioxide separation and capture system according to claim 4, characterized in that the control device controls the exhaust gas pressure regulator and the exhaust gas flow rate regulator so that the amount of heat required for evaporation of the refrigerant is supplied to the carbon dioxide solidifier based on the analysis results of the exhaust gas composition analyzer.

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