Carbon dioxide separation and recovery system

Abstract

The invention relates to a carbon dioxide separation and recovery system. A carbon dioxide separation and recovery system according to an embodiment of the present invention comprises: an exhaust gas sensible heat recovery unit that recovers sensible heat of exhaust gas and generates electric energy using the recovered sensible heat of the exhaust gas; a moisture removal unit that is connected to the exhaust gas sensible heat recovery unit and removes moisture contained in the sensible heat recovery exhaust gas from which sensible heat has been recovered by means of electric energy generated in the exhaust gas sensible heat recovery unit; and a separation part connected to the moisture removal part, receiving the moisture-removed sensible heat recovery exhaust gas from the moisture removal part, and separating solid carbon dioxide from the moisture-removed sensible heat recovery exhaust gas.

Description

Technical Field

[0001] The present invention relates to a carbon dioxide separation and recovery system. Background Art

[0002] As global warming accelerates, abnormal temperatures and rising sea levels are occurring around the world. The main reason for this intensification of global warming is the increase in greenhouse gas emissions, of which carbon dioxide emissions account for the largest proportion, so the need to reduce carbon dioxide emissions is increasing.

[0003] However, since the current industrial energy utilization efficiency has reached the highest level, excessive reduction of CO2 emissions may lead to a decline in industrial competitiveness. Therefore, while striving to reduce CO2 emissions, it is necessary to directly reduce CO2 through the capture, utilization and storage of CO2 (CCUS, hereinafter referred to as "CO2 capture, storage and utilization technology") as a technical countermeasure.

[0004] Carbon dioxide capture, storage and utilization technologies include technologies such as capturing carbon dioxide generated from industrial facilities, storing the captured carbon dioxide underground, and even technologies such as converting carbon dioxide into high-value-added useful resource materials.

[0005] Among them, carbon dioxide capture technology is generally divided into post-combustion capture technology (Post-combustion technology), pre-combustion capture technology (Pre-combustion technology) and pure oxygen combustion technology (Oxy-fuel combustion technology).

[0006] Specifically, post-combustion capture technology is a method for separating carbon dioxide from exhaust gases emitted when fossil fuels are burned with air. Pre-combustion capture technology is a method for separating carbon dioxide in the process of preparing hydrogen from fossil fuels. It is a method of converting the synthetic gas generated after gasification of fossil fuels into carbon dioxide and hydrogen through the water-gas shift reaction and then separating only carbon dioxide. Pure oxygen combustion technology is a method of burning fossil fuels without using air but by separating oxygen in the air to generate only carbon dioxide after combustion for separation.

[0007] Among them, post-combustion capture technology is divided into wet absorption method using amine series wet absorbent, dry absorption method using solid adsorbent, membrane separation method using diaphragm and phase separation method using phase change.

[0008] However, the wet absorption method has the following problems: the compression work required to liquefy the carbon dioxide separated from the wet absorbent after separation is large, and a high energy is required to regenerate the wet absorbent to its original state. The dry absorption method also has the following problems: the compression work required to liquefy the carbon dioxide separated from the solid adsorbent after separation is large, and a high energy is required to regenerate the solid adsorbent to its original state. In addition, the membrane separation method has the problems of difficulty in increasing capacity and poor durability due to membrane degradation. In addition, the phase separation method has the disadvantage that a pressure above the triple point is required to separate carbon dioxide from the exhaust gas liquid, so the energy efficiency is low.

[0009] In order to improve these problems, a very low temperature carbon capture method has been proposed, which separates and recovers the carbon dioxide contained in the exhaust gas in a solid state by cooling the exhaust gas to a temperature at which the carbon dioxide contained in the exhaust gas freezes. The very low temperature carbon capture method has the advantages of being able to separate and recover high-concentration carbon dioxide and being able to seal it immediately after capture, but there is a problem that the energy required to freeze the carbon dioxide contained in the exhaust gas increases as the concentration of the exhaust gas increases. In addition, there is also a problem that when the moisture contained in the exhaust gas is not completely removed, the moisture causes the purity of the carbon dioxide separated and recovered from the exhaust gas to decrease and the equipment to be damaged.

[0010] Therefore, it is necessary to develop a carbon dioxide separation and recovery system that utilizes the sensible heat of the recovered exhaust gas to effectively remove the moisture contained in the exhaust gas, which can not only improve the purity of the carbon dioxide separated and recovered from the exhaust gas, but also save the energy consumed in separating and recovering carbon dioxide from the exhaust gas, thereby improving energy efficiency. Summary of the invention

[0011]

Technical issues

[0012] The embodiments of the present invention are proposed to solve the above-mentioned existing problems, and the purpose is to provide a carbon dioxide separation and recovery system, which utilizes the sensible heat of the recovered exhaust gas to effectively remove the moisture contained in the exhaust gas, which can not only improve the purity of the carbon dioxide separated and recovered from the exhaust gas, but also save the energy consumed in separating and recovering carbon dioxide from the exhaust gas, thereby having improved energy efficiency.

[0013]

Technical solution

[0014] According to one aspect of the present invention, a carbon dioxide separation and recovery system can be provided, comprising: an exhaust gas sensible heat recovery section, which recovers the sensible heat of the exhaust gas and generates electric energy by using the recovered sensible heat of the exhaust gas; a moisture removal section, which is connected to the exhaust gas sensible heat recovery section, and uses the electric energy generated in the exhaust gas sensible heat recovery section to remove moisture contained in the sensible heat recovered exhaust gas from which the sensible heat has been recovered; and a separation section, which is connected to the moisture removal section, receives the sensible heat recovered exhaust gas from which the moisture has been removed from the moisture removal section, and separates solid carbon dioxide from the sensible heat recovered exhaust gas from which the moisture has been removed.

[0015] Furthermore, it may also include: a first flow channel, which provides a path for the flow of a first refrigerant capable of recovering the sensible heat of the exhaust gas by performing heat exchange with the exhaust gas; and a second flow channel, which provides a path for the flow of a second refrigerant capable of removing the moisture contained in the sensible heat recovery exhaust gas by performing heat exchange with the sensible heat recovery exhaust gas.

[0016] Furthermore, the moisture removal section may include: a moisture removal section side compressor, which is arranged on the second flow channel; a moisture removal section side heat exchanger, which is arranged on the second flow channel and cools the second refrigerant discharged from the moisture removal section side compressor; and a condenser, which is arranged on the second flow channel and allows the second refrigerant cooled in the moisture removal section side heat exchanger to exchange heat with the sensible heat recovery exhaust gas to condense moisture contained in the sensible heat recovery exhaust gas.

[0017] Furthermore, the exhaust gas sensible heat recovery section includes: a sensible heat recovery section side heat exchanger, which is arranged on the first flow channel and transfers the sensible heat of the exhaust gas to the first refrigerant; and a generator, which is arranged on the first flow channel and receives the first refrigerant discharged from the sensible heat recovery section side heat exchanger and recovers the sensible heat of the exhaust gas recovered to the first refrigerant as the electric energy. The electric energy recovered by the generator can be supplied to the moisture removal section side compressor.

[0018] Furthermore, the exhaust gas sensible heat recovery unit may include: a generator, which is arranged on the first flow channel and recovers the sensible heat of the exhaust gas recovered into the first refrigerant as the electrical energy; a recuperator, which is arranged on the first flow channel and cools the first refrigerant that has passed through the generator; and a radiator, which is arranged on the first flow channel and removes heat of the first refrigerant discharged from the recuperator.

[0019] Furthermore, it also includes a refrigerant heat recovery unit that recovers heat from the second refrigerant that has exchanged heat with the sensible heat recovery exhaust gas to the first refrigerant. The refrigerant heat recovery unit includes a refrigerant heat recovery unit side compressor that receives and compresses the first refrigerant that has passed through the radiator. The first refrigerant compressed by the refrigerant heat recovery unit side compressor can be supplied to the moisture removal unit side heat exchanger.

[0020] Furthermore, the exhaust gas sensible heat recovery unit further includes a sensible heat recovery unit-side compressor that receives and compresses the first refrigerant that has passed through the radiator, and the first refrigerant compressed by the sensible heat recovery unit-side compressor may be supplied to the recuperator.

[0021] Furthermore, the sensible heat recovery unit-side heat exchanger may receive at least one of the first refrigerant exhausted from the recuperator and the first refrigerant exhausted from the moisture removal unit-side heat exchanger to perform heat exchange with the exhaust gas.

[0022] In addition, the condenser includes: a main body portion, to which the sensible heat recovery exhaust gas is supplied; a tube portion, which is located inside the main body portion, to which the second refrigerant is supplied to flow; and a surface treatment portion, which is located at least in a portion of the outer surface of the tube portion and is made of a hydrophobic material. The moisture contained in the sensible heat recovery exhaust gas supplied to the main body portion is condensed and removed by the cold and heat of the second refrigerant supplied to the tube portion, and the sensible heat recovery exhaust gas can be cooled so that the density of the sensible heat recovery exhaust gas increases.

[0023] Furthermore, the separation section includes: a separation section side compressor, which is connected to the condenser, receives the sensible heat recovery exhaust gas from which the moisture has been removed and the density has been increased, and compresses it to generate compressed gas; a precooler, which is connected to the separation section side compressor, precools the compressed gas; and a separator, which is connected to the precooler, separates the solid carbon dioxide from the compressed gas precooled in the precooler, and the remaining compressed gas after the solid carbon dioxide is separated can be supplied to the precooler and undergo heat exchange with the compressed gas that has passed through the separation section side compressor.

[0024] Furthermore, it also includes: a supply unit connected to the moisture removal unit side heat exchanger for supplying a cold or heat transfer fluid to the moisture removal unit side heat exchanger; the moisture removal unit side heat exchanger can perform heat exchange between the cold or heat transfer fluid supplied by the supply unit and the second refrigerant discharged from the moisture removal unit side compressor to cool the second refrigerant.

[0025] [Effects of the invention]

[0026] According to an embodiment of the present invention, the purity of carbon dioxide separated and recovered from the exhaust gas can be improved by converting sensible heat recovered from the exhaust gas into electrical energy and using the converted electrical energy to effectively remove moisture contained in the exhaust gas.

[0027] In addition, the density of the exhaust gas increases during the process of removing moisture contained in the exhaust gas using electrical energy converted from sensible heat recovered from the exhaust gas, thereby significantly reducing the compression work required during the process of separating and recovering carbon dioxide from the exhaust gas.

[0028] In addition, heat generated in the process of removing moisture contained in the exhaust gas using electric energy converted from sensible heat recovered from the exhaust gas is used again for electric energy conversion, thereby having an effect of improving energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. 1 is a process diagram showing a carbon dioxide separation and recovery system according to an embodiment of the present invention.

[0030] Figure 2 It is shown Figure 1 Conceptual diagram of the moisture removal section of the carbon dioxide separation and recovery system.

[0031] Figure 3 FIG. 4 is a process diagram showing a carbon dioxide separation and recovery system according to another embodiment of the present invention.

[0032] [Description of Reference Numerals]

[0033] 1. 1': Carbon dioxide separation and recovery system 2: Exhaust gas emission source

[0034] 10: Exhaust gas sensible heat recovery unit 11: Sensible heat recovery unit side heat exchanger

[0035] 12: Generator 13: Reheater

[0036] 14: Radiator 15: Compressor on the sensible heat recovery side

[0037] 20, 20': Moisture removal unit 21: Moisture removal unit side compressor

[0038] 22, 22': Heat exchanger on the moisture removal side 23: Expansion valve

[0039] 24: Condenser 30: Separation unit

[0040] 31: Separation side compressor 32: Precooler

[0041] 33: Separator 40: Refrigerant heat recovery unit

[0042] 41: Refrigerant heat recovery unit side compressor 50: Supply unit

[0043] 111: Pre-condenser 241: Main body

[0044] 242: Tube 243: Surface treatment

[0045] 2411: Supply pipeline 2412: Discharge pipeline

[0046] 2421: Upper tube 2422: Connecting tube

[0047] 2423: Down tube DETAILED DESCRIPTION

[0048] Specific embodiments for implementing the inventive concept will be described in detail below with reference to the accompanying drawings.

[0049] Furthermore, when describing the present invention, if it is considered that a detailed description of related well-known configurations or functions may obscure the gist of the present invention, such detailed description will be omitted.

[0050] Furthermore, when it is described that a certain component is “connected” to another component, it should be understood that it may be directly connected to the other component, but another component may exist in between.

[0051] The terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. Unless the context clearly dictates otherwise, an expression in the singular includes an expression in the plural.

[0052] In addition, it should be stated in advance that the expressions such as one side, the other side, the upper side, and the lower side in this specification are described based on the illustrations. If the direction of the object changes, there may be another description method. For the same reason, some components are enlarged, omitted or briefly shown in the drawings, and the size of each component does not fully reflect the actual size.

[0053] In addition, terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited to these terms. These terms are only used to distinguish one component from other components.

[0054] The word “comprising” used in the specification means to specify specific features, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other specific features, regions, integers, steps, operations, elements and components and / or groups.

[0055] The specific structure of a carbon dioxide separation and recovery system according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0056] See also Figure 1 and Figure 2A carbon dioxide separation and recovery system 1 according to an embodiment of the present invention may include an exhaust gas sensible heat recovery unit 10 , a moisture removal unit 20 , a separation unit 30 , and a refrigerant heat recovery unit 40 .

[0057] The exhaust gas sensible heat recovery unit 10 can receive the exhaust gas from the exhaust gas emission source 2 and recover the sensible heat of the exhaust gas. In addition, the sensible heat of the recovered exhaust gas can be used to generate electric energy. As an example, the exhaust gas discharged from the exhaust gas emission source 2 can be flue gas composed of nitrogen, oxygen, carbon dioxide and water vapor. However, this is only an example provided for the convenience of explanation, and the components of the exhaust gas can be multiple components including at least carbon dioxide.

[0058] To this end, the exhaust gas sensible heat recovery unit 10 may include a sensible heat recovery unit-side heat exchanger 11 , a generator 12 , a recuperator 13 , a radiator 14 , and a sensible heat recovery unit-side compressor 15 .

[0059] In this case, the heat exchanger 11 on the sensible heat recovery part side, the generator 12, the recuperator 13, the radiator 14, and the compressor 15 on the sensible heat recovery part side may be arranged on the first flow channel L1. Here, the first flow channel L1 may provide a path for the first refrigerant to flow, and may form a closed loop in which the first refrigerant may circulate among the heat exchanger 11 on the sensible heat recovery part side, the generator 12, the recuperator 13, the radiator 14, and the compressor 15 on the sensible heat recovery part side. For example, the first refrigerant may be a refrigerant that can perform heat exchange with the exhaust gas to recover the sensible heat of the exhaust gas.

[0060] The sensible heat recovery unit side heat exchanger 11 can transfer the sensible heat of the exhaust gas to the first refrigerant flowing through the first flow channel L1. The sensible heat recovery unit side heat exchanger 11 can receive at least one of the first refrigerant discharged from the recuperator 13 and the first refrigerant discharged from the moisture removal unit side heat exchanger 22 of the moisture removal unit 20 described below to perform heat exchange with the exhaust gas. In other words, the sensible heat recovery unit side heat exchanger 11 can transfer the sensible heat of the exhaust gas to the first refrigerant to reduce the temperature of the exhaust gas.

[0061] In addition, since the exhaust gas discharged from the sensible heat recovery part side heat exchanger 11 is exhaust gas from which sensible heat has been removed, the exhaust gas discharged from the sensible heat recovery part side heat exchanger 11 is referred to as "sensible heat recovery exhaust gas" for convenience of description below.

[0062] In this case, the temperature of the sensible heat recovery exhaust gas discharged from the sensible heat recovery part side heat exchanger 11 may have a temperature close to the atmospheric temperature, and may be supplied to the pre-condenser 111. Therefore, at least a portion of the moisture contained in the sensible heat recovery exhaust gas may be removed by the pre-condenser 111, and the rest of the moisture contained in the sensible heat recovery exhaust gas may be removed by the condenser 24 of the moisture removal part 20 described below.

[0063] The generator 12 receives the first refrigerant discharged from the sensible heat recovery unit side heat exchanger 11 and can recover the sensible heat of the exhaust gas recovered to the first refrigerant as electric energy. The electric energy recovered in this way can be supplied to the moisture removal unit side compressor 21 of the moisture removal unit 20 described below.

[0064] The recuperator 13 can cool the first refrigerant that has passed through the generator 12. The recuperator 13 can perform heat exchange between the first refrigerant compressed by the sensible heat recovery part side compressor 15 and the first refrigerant that has passed through the generator 12. Since the heat of the first refrigerant is removed by the radiator 14 before the first refrigerant is compressed in the sensible heat recovery part side compressor 15, the first refrigerant compressed in the sensible heat recovery part side compressor 15 can cool the first refrigerant that has passed through the generator 12.

[0065] The radiator 14 may remove heat from the first refrigerant discharged from the recuperator 13. The first refrigerant having removed heat in the radiator 14 may be supplied to the sensible heat recovery unit side compressor 1 or the refrigerant heat recovery unit side compressor 41 of the refrigerant heat recovery unit 40 described below. This will be described later.

[0066] The sensible heat recovery part side compressor 15 can receive and compress the first refrigerant that has passed through the radiator 14. The first refrigerant compressed in the sensible heat recovery part side compressor 15 can be supplied to the recuperator 13, and the cold heat of the first refrigerant supplied to the recuperator 13 can be transferred to the first refrigerant that has passed through the generator 12.

[0067] The moisture removal unit 20 can remove moisture contained in the sensible heat recovery exhaust gas using the electric energy generated in the exhaust gas sensible heat recovery unit 10. To this end, the moisture removal unit 20 can include a moisture removal unit side compressor 21, a moisture removal unit side heat exchanger 22, an expansion valve 23, and a condenser 24.

[0068] In this case, the moisture removal unit side compressor 21, the moisture removal unit side heat exchanger 22, the expansion valve 23 and the condenser 24 can be arranged on the second flow channel L2. Here, the second flow channel L2 is a portion that provides a path for the flow of the second refrigerant that can exchange heat with the sensible heat recovery exhaust gas to remove moisture contained in the sensible heat recovery exhaust gas, and can form a closed loop in which the second refrigerant can circulate through the moisture removal unit side compressor 21, the moisture removal unit side heat exchanger 22, the expansion valve 23 and the condenser 24.

[0069] The moisture removal unit-side compressor 21 can be driven by the electric energy generated by the generator 12 , and can compress the second refrigerant discharged from the condenser 24 .

[0070] The moisture removal part side heat exchanger 22 can cool the second refrigerant discharged from the moisture removal part side compressor 21. The moisture removal part side heat exchanger 22 can perform heat exchange between the second refrigerant compressed in the moisture removal part side compressor 21 and the first refrigerant supplied from the exhaust gas sensible heat recovery part 10. Here, the first refrigerant supplied from the exhaust gas sensible heat recovery part 10 to the moisture removal part side heat exchanger 22 can be a refrigerant that is cooled and compressed after being used in the generator 12 to generate electric energy, and the first refrigerant that has undergone heat exchange with the second refrigerant can be recovered to the exhaust gas sensible heat recovery part 10.

[0071] The expansion valve 23 can expand the second refrigerant discharged from the moisture removing unit side heat exchanger 22. The second refrigerant expanded by the expansion valve 23 can be supplied to the condenser 24.

[0072] The condenser 24 can condense the moisture contained in the sensible heat recovery exhaust gas by exchanging heat with the second refrigerant that has passed through the expansion valve 23. Here, the sensible heat recovery exhaust gas supplied to the condenser 24 can be the sensible heat recovery exhaust gas that has passed through the pre-condenser 111 disposed at the front end of the condenser 24. At least a portion of the moisture contained in the sensible heat recovery exhaust gas can be removed when passing through the pre-condenser 111.

[0073] In this case, the condenser 24 may include a main body 241, a tube 242 and a surface treatment portion 243. The sensible heat recovery exhaust gas is supplied to the main body 241. The tube 242 is located inside the main body 241. The second refrigerant supplied to the tube 242 flows in the tube 242. The surface treatment portion 243 is located on at least a portion of the outer surface of the tube 242 and is made of a hydrophobic material.

[0074] The body portion 241 may have an inner space in which the sensible heat removal exhaust gas, from which at least a portion of moisture has been removed in the process of passing through the pre-condenser 111, can flow. Figure 2As shown, the sensible heat removal exhaust gas A supplied to the inside of the main body 241 through the supply pipe 2411 can be heat-exchanged with the second refrigerant B supplied to one end of the pipe part 242, and the sensible heat removal exhaust gas C that has been heat-exchanged with the second refrigerant can be discharged through the discharge pipe 2412. In addition, the second refrigerant D that has been heat-exchanged with the sensible heat removal exhaust gas A supplied to the inside of the main body 241 through the supply pipe 2411 can be discharged through the other end of the pipe part 242.

[0075] The tube portion 242 is a portion connected to the second flow channel L2 and supplied with the second refrigerant, and may be disposed inside the main body portion 241. Such a tube portion 242 may be divided into a lower tube 2421 connected to the second flow channel L2 at the lower portion of the main body portion 241, an upper tube 2423 connected to the second flow channel L2 at the upper portion of the main body portion 241, and a connecting tube 2422 connecting the lower tube 2421 and the upper tube 2423. If the tube portion 242 is divided into the lower tube 2421, the connecting tube 2422, and the upper tube 2423, the heat exchange efficiency between the sensible heat removal exhaust gas and the second refrigerant may be adjusted. For example, the lower tube 2421, the connecting tube 2422, and the upper tube 2423 may be formed as one body, or may be manufactured separately and then connected to each other.

[0076] In addition, since the second refrigerant supplied to the inside of the tube portion 242 is a fluid that can be cooled to above -40°C, the moisture contained in the sensible heat removal exhaust gas can condense on the outer side of the tube portion 242, and the sensible heat removal exhaust gas is cooled, so the density of the sensible heat removal exhaust gas can be increased. In other words, since the outer side of the tube portion 242 is a surface on which the sensible heat removal exhaust gas can condense, if a hydrophobic material is coated on at least a portion of the outer side of the tube portion 242, the moisture will not condense on the outer side of the tube portion 242, and can be peeled off in the form of moisture particles while condensing. The peeled moisture particles can be accumulated in the lower part of the main body 241, and can be discharged to the outside of the main body 241 when necessary.

[0077] In addition, when the sensible heat removal exhaust gas supplied to the main body 241 performs heat exchange with the second refrigerant flowing through the tube portion 242, the temperature of the sensible heat removal exhaust gas decreases and the density of the sensible heat removal exhaust gas can be increased. The sensible heat removal exhaust gas with increased density can be supplied to the separation section side compressor 31 of the separation section 30 described below. In other words, the density of the sensible heat removal exhaust gas supplied to the separation section side compressor 31 of the separation section 30 described below increases, so the power consumption of the separation section side compressor 31 of the separation section 30 described below can be reduced.

[0078] The separation unit 30 may receive the sensible heat recovery exhaust gas from which moisture has been removed from the moisture removal unit 20 and separate solid carbon dioxide from the sensible heat recovery exhaust gas from which moisture has been removed. To this end, the separation unit 30 may include a separation unit side compressor 31 , a precooler 32 , and a separator 33 .

[0079] The separator side compressor 31 can be connected to the condenser 24, and can receive the sensible heat recovery exhaust gas from which moisture has been removed from the condenser 24 and compress it to generate compressed gas. Since the sensible heat removal exhaust gas supplied to the separator side compressor 31 has been dehydrated in the condenser 24, it is possible to prevent damage to the separator side compressor 31 that may be caused by moisture in advance. In addition, the sensible heat removal exhaust gas supplied to the separator side compressor 31 is not only dehydrated in the condenser 24, but also has an increased density, so compared with the prior art, the power consumption of the separator side compressor 31 can be reduced.

[0080] The precooler 32 can be connected to the separation part side compressor 31 to receive the compressed gas supplied from the separation part side compressor 31, and can precool the compressed gas. Since the compressed gas supplied to the precooler 32 does not contain water, the damage to the precooler 32 caused by water condensation during the precooling of the compressed gas can be minimized.

[0081] The separator 33 may be connected to the precooler 32, and may separate solid carbon dioxide from the compressed gas precooled in the precooler 32. In other words, the solid carbon dioxide and gaseous nitrogen / oxygen may be separated by the separator 33. Here, the gaseous nitrogen / oxygen refers to the gas remaining after the solid carbon dioxide contained in the compressed gas is separated, and therefore, the separated gaseous nitrogen / oxygen is referred to as "remaining compressed gas" hereinafter for the convenience of description.

[0082] In this case, since the precooled compressed gas supplied to the separator 33 does not contain moisture, the purity of the solid carbon dioxide separated by the separator 33 can be higher than before. In addition, since the carbon dioxide is separated and recovered in a solid state by the separator 33, the storage density of the carbon dioxide can be increased, and since it can be separated and stored at the same time as being captured, the process can be simplified. Therefore, when applied to mobility, carbon dioxide can be captured and stored with the smallest space.

[0083] In addition, the remaining compressed gas may be supplied to the precooler 32 to exchange heat with the compressed gas that has passed through the separator-side compressor 31. The remaining compressed gas that has precooled the compressed gas may be discharged to the outside.

[0084] The refrigerant heat recovery unit 40 may recover heat of the second refrigerant having exchanged heat with the sensible heat recovery exhaust gas to the first refrigerant. To this end, the refrigerant heat recovery unit 40 may include a refrigerant heat recovery unit-side compressor 41 that receives and compresses the first refrigerant having passed through the radiator 14 .

[0085] The refrigerant heat recovery unit side compressor 41 may receive the first refrigerant through the third flow path L3 , and the first refrigerant compressed in the refrigerant heat recovery unit side compressor 41 may be supplied to the moisture removal unit side heat exchanger 22 .

[0086] In addition, the cold heat of the first refrigerant supplied to the moisture removal unit side heat exchanger 22 can be used to cool the second refrigerant that has passed through the moisture removal unit side compressor 21. The first refrigerant that has cooled the second refrigerant can be returned to the first flow channel L1 through the fourth flow channel L44, and can be used again to generate electric energy using the sensible heat of the exhaust gas. Therefore, the overall system efficiency can be improved.

[0087] The carbon dioxide separation and recovery system 1 having the above-described structure converts the sensible heat recovered from the exhaust gas into electrical energy, and utilizes the converted electrical energy to effectively remove moisture contained in the exhaust gas, thereby having the effect of improving the purity of carbon dioxide separated and recovered from the exhaust gas.

[0088] Furthermore, the density of the exhaust gas increases in the process of removing moisture contained in the exhaust gas using electrical energy converted from the sensible heat recovered from the exhaust gas, thereby significantly reducing the compression work required in the process of separating and recovering carbon dioxide from the exhaust gas.

[0089] Furthermore, heat generated in the process of removing moisture contained in the exhaust gas using electric energy converted from sensible heat recovered from the exhaust gas is reused for electric energy conversion, thereby improving energy efficiency.

[0090] See below Figure 3 A carbon dioxide separation and recovery system 1 ′ according to another embodiment of the present invention is described.

[0091] See also Figure 3 According to another embodiment of the present invention, a carbon dioxide separation and recovery system 1' may include an exhaust gas sensible heat recovery unit 10, a moisture removal unit 20', a separation unit 30 and a supply unit 50. However, due to Figure 3 The carbon dioxide separation and recovery system 1' shown in the figure is substantially the same as that of the one shown in the figure except for the water removal unit 20' and the supply unit 50. Figure 1 and Figure 2 The carbon dioxide separation and recovery systems 1 described are the same, and therefore the moisture removal unit 20 ′ and the supply unit 50 that are different will be described below.

[0092] The moisture removal unit 20' may include a moisture removal unit side compressor 21, a moisture removal unit side heat exchanger 22', an expansion valve 23, and a condenser 24. However, since the moisture removal unit side compressor 21, the expansion valve 23, and the condenser 24 are substantially the same as those in the embodiment of the present invention, Figure 1 and Figure 2 The moisture removal part side compressor 21, the expansion valve 23, and the condenser 24 described above are the same, and therefore the moisture removal part side heat exchanger 22' which is different will be described below.

[0093] The moisture removal part side heat exchanger 22' may receive the cold heat transfer fluid through the supply part 50. To this end, the moisture removal part side heat exchanger 22' may be connected to the supply part 50 through the fifth flow passage L5.

[0094] In this case, the moisture removal unit side heat exchanger 22' can cool the second refrigerant by heat exchange between the cold and heat transfer fluid supplied from the supply unit 50 and the second refrigerant discharged from the moisture removal unit side compressor 21. The cold and heat transfer fluid that has exchanged heat with the second refrigerant can be discharged to the outside, or recovered to the supply unit 50 as needed. For example, the cold and heat transfer fluid can be a liquid fuel such as liquefied natural gas (LNG).

[0095] Although the embodiments of the present invention are described above as specific implementation methods, this is only an example, and the present invention is not limited thereto, and should be interpreted as having the broadest scope that follows the basic ideas disclosed in this specification. A person of ordinary skill in the art can implement patterns of unspecified shapes by combining / replacing the disclosed implementation methods, but this does not depart from the scope of the present invention. In addition, a person of ordinary skill in the art can easily change or deform the disclosed implementation methods according to this specification, and it is obvious that these changes or deformations also belong to the scope of rights of the present invention.

Claims

1. A carbon dioxide separation and recovery system, comprising: an exhaust gas sensible heat recovery unit, which recovers the sensible heat of the exhaust gas and generates electric energy using the recovered sensible heat of the exhaust gas; a moisture removal unit connected to the exhaust gas sensible heat recovery unit, and removing moisture contained in the sensible heat recovered exhaust gas from which the sensible heat has been recovered, using the electric energy generated in the exhaust gas sensible heat recovery unit; as well as The separation unit is connected to the moisture removal unit, receives the sensible heat recovery exhaust gas from which the moisture has been removed from the moisture removal unit, and separates solid carbon dioxide from the sensible heat recovery exhaust gas from which the moisture has been removed.

2. The carbon dioxide separation and recovery system according to claim 1, further comprising: a first flow passage providing a path for a first refrigerant to flow that can recover the sensible heat of the exhaust gas by exchanging heat with the exhaust gas; as well as The second flow passage provides a path for a second refrigerant to flow, capable of removing the moisture contained in the sensible heat recovery exhaust gas by exchanging heat with the sensible heat recovery exhaust gas.

3. The carbon dioxide separation and recovery system according to claim 2, wherein the moisture removal unit comprises: a moisture removal unit-side compressor, which is disposed on the second flow path; a moisture removal unit-side heat exchanger disposed on the second flow path and cooling the second refrigerant discharged from the moisture removal unit-side compressor; as well as The condenser is disposed on the second flow path and exchanges heat between the second refrigerant cooled in the moisture removal unit-side heat exchanger and the sensible heat recovery exhaust gas to condense moisture contained in the sensible heat recovery exhaust gas.

4. The carbon dioxide separation and recovery system according to claim 3, wherein the exhaust gas sensible heat recovery unit comprises: a sensible heat recovery unit-side heat exchanger, disposed on the first flow channel, and transferring the sensible heat of the exhaust gas to the first refrigerant; as well as a generator disposed on the first flow channel, receiving the first refrigerant discharged from the sensible heat recovery unit side heat exchanger, and recovering the sensible heat of the exhaust gas recovered into the first refrigerant as the electric energy, The electric energy recovered by the generator is supplied to the moisture removal unit-side compressor.

5. The carbon dioxide separation and recovery system according to claim 3, wherein the exhaust gas sensible heat recovery unit comprises: a generator disposed on the first flow channel and configured to recover the sensible heat of the exhaust gas recovered into the first refrigerant as the electrical energy; a reheater, disposed on the first flow channel, for cooling the first refrigerant that has passed through the generator; as well as A radiator is disposed on the first flow channel and removes heat from the first refrigerant discharged from the recuperator.

6. The carbon dioxide separation and recovery system according to claim 5, further comprising: a refrigerant heat recovery unit that recovers heat of the second refrigerant that has exchanged heat with the sensible heat recovery exhaust gas to the first refrigerant, The refrigerant heat recovery unit comprises: a compressor on the refrigerant heat recovery part side, which receives and compresses the first refrigerant having passed through the radiator, The first refrigerant compressed by the refrigerant heat recovery unit-side compressor is supplied to the moisture removal unit-side heat exchanger.

7. The carbon dioxide separation and recovery system according to claim 6, wherein the exhaust gas sensible heat recovery unit further comprises: a compressor on the sensible heat recovery part side, which receives and compresses the first refrigerant that has passed through the radiator; The first refrigerant compressed by the sensible heat recovery unit-side compressor is supplied to the recuperator.

8. The carbon dioxide separation and recovery system according to claim 7, wherein the sensible heat recovery unit side heat exchanger receives at least one of the first refrigerant discharged from the recuperator and the first refrigerant discharged from the moisture removal unit side heat exchanger to perform heat exchange with the exhaust gas.

9. The carbon dioxide separation and recovery system according to claim 3, wherein the condenser comprises: a main body portion to which the sensible heat recovery exhaust gas is supplied; a pipe portion located inside the main body portion, and the second refrigerant is supplied to flow through the pipe portion; as well as The surface treatment portion is located at least in a portion of the outer side surface of the tube portion and is made of a hydrophobic material. The moisture contained in the sensible heat recovery exhaust gas supplied to the main body is condensed and removed by the cold heat of the second refrigerant supplied to the tube portion, and the sensible heat recovery exhaust gas is cooled so that the density of the sensible heat recovery exhaust gas increases.

10. The carbon dioxide separation and recovery system according to claim 9, wherein the separation unit comprises: a separation unit side compressor connected to the condenser, receiving the sensible heat recovery exhaust gas from which the moisture has been removed and the density has been increased, and compressing the exhaust gas to generate compressed gas; a precooler connected to the separator-side compressor to precool the compressed gas; and a separator connected to the precooler, separating the solid carbon dioxide from the compressed gas precooled in the precooler, The remaining compressed gas after the solid carbon dioxide is separated is supplied to the precooler, and is heat-exchanged with the compressed gas that has passed through the separator-side compressor.

11. The carbon dioxide separation and recovery system according to claim 3, further comprising: a supply unit connected to the moisture removal unit side heat exchanger and supplying a cold and heat transfer fluid to the moisture removal unit side heat exchanger; The moisture removal unit-side heat exchanger exchanges heat between the cold heat transfer fluid supplied from the supply unit and the second refrigerant discharged from the moisture removal unit-side compressor to cool the second refrigerant.

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