Carbon dioxide rectifying and drying system and carbon dioxide purifying and liquefying system
By using the distillation method and the recovery separator in the carbon dioxide rectification and drying system, the shortcomings of the existing adsorption drying technology in terms of energy consumption, investment, maintenance, etc. are solved, and more efficient dehydration and near-zero emissions are achieved.
Patent Information
- Application Number
- CN202421532022.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-28
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-06-28
AI Technical Summary
The existing carbon dioxide adsorption and drying technology has shortcomings in energy consumption, investment, maintenance, etc., especially the directional deviation of adsorption heat and heating regeneration and low-temperature distillation.
The carbon dioxide distillation and drying system is adopted, which includes a compression purification subsystem, a distillation and dehydration subsystem and a refrigeration subsystem. The dehydration is carried out through the distillation method, and the carbon dioxide in the dehydrated distillation tower bottom liquid is recovered by a recycling separator to achieve near-zero emissions.
A better dehydration effect is achieved, avoiding the problems of high equipment investment and high maintenance costs in adsorption and drying technology, and reducing the energy consumption of subsequent stages through distillation, significantly improving the practicality of distillation and drying technology.
Smart Images
Figure CN222738829U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of gas drying, in particular to a carbon dioxide distillation drying system and a carbon dioxide purification liquefaction system. Background Art
[0002] Carbon dioxide is an important resource, which has important application value in industrial application fields such as oil extraction, chemical raw materials, welding, and food-grade application fields. Carbon dioxide for resource utilization usually comes from various industrial exhaust gases. Among various industrial exhaust gases, the main component is carbon dioxide, which usually contains a small amount of water. In the drying process, in order to avoid freezing and blocking that may occur during low-temperature distillation, it is usually necessary to remove the water to less than 10ppm. The existing technology usually uses adsorption drying technology for dehydration. The adsorption tower is generally 2 or 3, and the adsorbent usually uses 3A molecular sieve (alkali metal aluminosilicate). Although the adsorption drying technology can achieve the effect of drying and dehydration, the adsorption heat generated during the adsorption process needs to be cooled and removed, and heating regeneration requires heat consumption. The actual service life of the molecular sieve is generally 2 to 3 years, and the service life is short. There are many programmable valves, the price is expensive, and frequent start and stop are easy to damage. Some adsorption drying models also require a certain proportion of gas source as backflush gas, resulting in gas source waste. In general, the existing carbon dioxide adsorption drying technology still has shortcomings in energy consumption, investment, maintenance, etc. Utility Model Content
[0003] In order to solve the defects of the existing carbon dioxide adsorption drying technology in terms of energy consumption, investment, maintenance, etc., especially the directional deviation between adsorption heat, heating regeneration, etc. and the cooling required for low-temperature distillation, the utility model is proposed to provide a carbon dioxide distillation and drying system and a carbon dioxide purification and liquefaction system that overcome the above problems or at least partially solve the above problems.
[0004] In a first aspect, an embodiment of the utility model provides a carbon dioxide distillation and drying system, which may include: a compression and purification subsystem, a distillation and dehydration subsystem, and a refrigeration subsystem;
[0005] The distillation and dehydration subsystem may include: a precooler, a gas-liquid separator, a recovery separator, a dehydration distillation tower, a reboiler and a tower top condenser;
[0006] One end of the compression and purification subsystem is externally connected to the raw gas pipeline, and the other end is connected to the precooler; the precooler, the gas-liquid separator, the recovery separator and the dehydration distillation tower are connected in sequence; the top of the dehydration distillation tower is connected to the top condenser, the bottom of the dehydration distillation tower is connected to the reboiler, and the recovery separator is connected to the bottom of the dehydration distillation tower; the refrigeration subsystem is connected to the cold sides of the precooler and the top condenser through pipelines to form a cooling circuit.
[0007] In one embodiment, the refrigeration subsystem may include: a refrigeration compressor, a condenser and a throttle valve; the refrigeration compressor, the condenser, the throttle valve, the cold side of the tower top condenser and the cold side of the precooler are connected in sequence through pipelines to form a cooling circuit.
[0008] In another embodiment, the refrigeration compressor, the condenser, the throttling valve, the hot side of the reboiler, the cold side of the top condenser and the cold side of the precooler are connected in sequence through pipelines to form a closed loop.
[0009] In another embodiment, the compression and purification subsystem may include: a raw gas compressor; one end of the raw gas compressor is externally connected to a raw gas pipeline, and the other end is connected to the precooler.
[0010] In another embodiment, the compression and purification subsystem may further include: a purification device located between the raw gas compressor and the precooler, wherein the purification device is used to remove sulfur-containing impurities and / or hydrocarbon impurities in the raw gas.
[0011] In another embodiment, the raw gas compressor is a three-stage compressor or a four-stage compressor, and the raw gas compressor is provided with an interstage cooler and an aftercooler.
[0012] In another embodiment, the recovery separator includes a middle air inlet, a top outlet, an upper liquid inlet and a bottom outlet;
[0013] The upper gas outlet of the gas-liquid separator is connected to the middle gas inlet of the recovery separator through a pipeline; the top outlet of the recovery separator is connected to the middle feed inlet of the dehydration distillation tower through a pipeline; the upper liquid inlet of the recovery separator is connected to the bottom outlet of the dehydration distillation tower through a pipeline; the bottom outlet of the recovery separator is used to discharge the separated liquid.
[0014] In another embodiment, the dehydration distillation tower is a packed tower or a plate tower.
[0015] In a second aspect, an embodiment of the utility model provides a carbon dioxide purification and liquefaction system, which may include: a carbon dioxide gas source supply system, a carbon dioxide distillation and purification system or a carbon dioxide liquefaction system, and a carbon dioxide distillation and drying system as described in the first aspect;
[0016] The carbon dioxide gas source supply system is connected to the compression and purification subsystem through a pipeline; the carbon dioxide distillation and purification system or the carbon dioxide liquefaction system is connected to the top gas outlet of the dehydration distillation tower through a pipeline.
[0017] The beneficial effects of the above technical solution provided by the embodiment of the utility model at least include:
[0018] The embodiment of the utility model provides a carbon dioxide distillation drying system and a carbon dioxide purification liquefaction system. The drying system, on the one hand, realizes the distillation drying of carbon dioxide. Compared with the existing adsorption drying technology, it can obtain better dehydration effect, and well avoids the disadvantages of high equipment investment and high maintenance cost caused by the adsorption drying technology that needs to use adsorbents, programmable valves, etc.; on the second hand, through distillation dehydration, the exhaust temperature at the top of the dehydration distillation tower is reduced, which is beneficial to the distillation purification or liquefaction of subsequent sections, and the gas temperature increases after adsorption drying. In comparison, the system is more energy-efficient; on the third hand, by introducing a recovery separator, most of the carbon dioxide in the bottom liquid of the dehydration distillation tower is recovered, thereby achieving near-zero emission of carbon dioxide during the drying process, greatly improving the practicality of the distillation drying technology.
[0019] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by implementing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structures particularly pointed out in the written description and the drawings.
[0020] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0022] Figure 1 This is one of the structural diagrams of the carbon dioxide distillation and drying system in the embodiment of the utility model;
[0023] Figure 2 This is the second structural diagram of the carbon dioxide distillation and drying system in the embodiment of the utility model;
[0024] Figure 3 This is one of the structural schematic diagrams of the carbon dioxide purification and liquefaction system in the embodiment of the utility model;
[0025] Figure 4 This is the second structural diagram of the carbon dioxide purification and liquefaction system in the embodiment of the utility model;
[0026] Among them, 1-carbon dioxide distillation and drying system; 2-carbon dioxide gas source supply system; 3-carbon dioxide distillation and purification system; 4-carbon dioxide liquefaction system;
[0027] 11- compression and purification subsystem; 12- distillation and dehydration subsystem; 13- refrigeration subsystem;
[0028] 111-raw gas compressor; 112-purification equipment; 121-precooler; 122-gas-liquid separator; 123-recovery separator; 124-dehydration distillation tower; 125-reboiler; 126-tower top condenser; 131-refrigeration compressor; 132-condenser; 133-throttle valve. DETAILED DESCRIPTION
[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.
[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "far", "near", "front", "rear" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0032] The utility model provides a carbon dioxide distillation drying system, referring to Figure 1As shown, the carbon dioxide distillation and drying system 1 may include: a compression and purification subsystem 11, a distillation and dehydration subsystem 12 and a refrigeration subsystem 13; the distillation and dehydration subsystem 12 may include: a precooler 121, a gas-liquid separator 122, a recovery separator 123, a dehydration distillation tower 124, a reboiler 125 and a tower top condenser 126; one end of the compression and purification subsystem 11 is externally connected to the raw gas pipeline, and the other end is connected to the precooler 121; the precooler 121, the gas-liquid separator 122, the recovery separator 123 and the dehydration distillation tower 124 are connected in sequence; the top of the dehydration distillation tower 124 is connected to the tower top condenser 126, the bottom of the dehydration distillation tower 124 is connected to the reboiler 125, and the recovery separator 123 is connected to the bottom of the dehydration distillation tower 124; the refrigeration subsystem 13 is connected to the cold side fluid pipelines of the precooler 121 and the tower top condenser 126 through pipelines to form a cooling circuit.
[0033] The compression and purification subsystem in this embodiment is used to pressurize the raw gas, thereby increasing the pressure of the raw gas; at the same time, the raw gas can be purified to protect subsequent equipment. The distillation and dehydration subsystem is used to dry the raw gas, wherein the precooler and the gas-liquid separator are used to cool the saturated gas at the outlet of the raw gas compressor and separate the liquid water to reduce the load of the distillation and dehydration tower; the raw gas at the gas phase outlet of the gas-liquid separator enters the recovery separator; the recovery separator is used to recover the liquid collected at the bottom of the dehydration distillation tower, and under the evaporation of the high-temperature raw gas, most of the carbon dioxide in the liquid enters the raw gas, and more than 99% of the remaining liquid is water, achieving near-zero consumption of raw gas. The above-mentioned raw gas enters from the lower part of the dehydration distillation tower and merges with the rising steam from the bottom of the tower. The gas and liquid are subjected to heat and mass exchange on the tower plates of the dehydration distillation tower to achieve distillation separation of carbon dioxide and water, and dry qualified gas with a water content of less than 10 ppm is obtained at the top of the dehydration distillation tower; the above-mentioned reboiler is used to heat the liquid at the bottom of the dehydration distillation tower and provide rising steam to reduce the carbon dioxide content in the liquid at the bottom of the dehydration distillation tower; the tower top condenser is used to cool the exhaust gas at the top of the dehydration distillation tower to obtain reflux liquid.
[0034] In specific implementation, refer to Figure 1 and Figure 2 As shown, the recovery separator is provided with a liquid introduction pipe (a) and a gas evaporation pipe (b). The liquid introduction pipe is used to introduce the liquid at the bottom of the dehydration distillation tower to the bottom of the recovery separator. The gas evaporation pipe is used to pass the raw gas and increase the heat exchange area. The structure is a serpentine tube or a finned tube.
[0035] The recovery separator and dehydration distillation tower in this embodiment mainly utilize the principle that the boiling point difference between carbon dioxide and water is large and easy to separate; the boiling point of carbon dioxide is -78.45°C, and the boiling point of water is 100°C. In the mixed gas of the two, carbon dioxide is more easily volatilized and is a light component, while water is more difficult to volatilize and is a heavy component; the temperature of the raw gas introduced into the recovery separator is 10-35°C, so that the carbon dioxide evaporates quickly, while the water remains as a liquid; in the dehydration distillation tower, gas-liquid heat and mass exchange is carried out on the tower plate, the light component carbon dioxide evaporates into the rising gas, and the water content of the heavy component is condensed into the reflux liquid, eventually forming a tower component distribution with the highest carbon dioxide concentration in the top gas phase and the highest water content in the bottom liquid phase, thereby realizing the distillation separation of the two components.
[0036] The above-mentioned carbon dioxide distillation and drying system provided in this embodiment, on the one hand, realizes the distillation drying of carbon dioxide. Compared with the existing adsorption drying technology, it can obtain better dehydration effect, and well avoids the shortcomings of high equipment investment and high maintenance cost brought about by the adsorption drying technology that requires the use of adsorbents, programmable valves, etc.; on the second hand, through distillation dehydration, the exhaust temperature at the top of the dehydration distillation tower is reduced, which is beneficial to the distillation purification or liquefaction of subsequent stages, and the gas temperature increases after adsorption drying. In comparison, the system is more energy-efficient; on the third hand, by introducing a recovery separator, most of the carbon dioxide in the bottom liquid of the dehydration distillation tower is recovered, thereby achieving near-zero emissions of carbon dioxide during the drying process, greatly improving the practicality of the distillation drying technology.
[0037] In an alternative embodiment, referring to Figure 1 As shown, the refrigeration subsystem 13 may include: a refrigeration compressor 131, a condenser 132 and a throttle valve 133; the refrigeration compressor 131, the condenser 132, the throttle valve 133, the cold side of the tower top condenser 126 and the cold side of the precooler 121 are connected in sequence through pipelines to form a cooling circuit. The refrigeration subsystem includes main components such as a refrigeration compressor, a condenser, and a throttle valve, and is mainly used to provide the cooling capacity required by the tower top condenser and the precooler.
[0038] In another optional embodiment, further, the refrigeration subsystem is also used to provide the heat required by the reboiler, referring to Figure 2 As shown, the refrigeration compressor 131, the condenser 132, the throttle valve 133, the hot side of the reboiler 125, the cold side of the top condenser 126 and the cold side of the precooler 121 are connected in sequence through pipelines to form a closed loop.
[0039] The compressed refrigerant vapor discharged from the refrigeration compressor is condensed into liquid in the condenser and supercooled in the reboiler. Supercooling is conducive to reducing the throttling gasification rate and improving the refrigeration efficiency. The supercooled liquid refrigerant is throttled and cooled by the throttling valve, and passes through the top condenser and the precooler in turn. After providing cooling capacity, it is vaporized and enters the suction port of the refrigeration compressor to complete the refrigeration cycle. In this embodiment, liquid refrigerant is used to provide the heat required by the reboiler. The liquid refrigerant is supercooled, which reduces the gasification rate after throttling, improves the refrigeration efficiency, and thus reduces energy consumption.
[0040] In another alternative embodiment, referring to Figure 1 and Figure 2 As shown, the compression and purification subsystem 11 may include: a raw gas compressor 111; one end of the raw gas compressor 111 is connected to an external raw gas pipeline, and the other end is connected to a precooler 121.
[0041] In another alternative embodiment, referring to Figure 1 and Figure 2 As shown, the compression and purification subsystem 11 may further include: a purification device 112 located between the raw gas compressor 111 and the precooler 121, and the purification device 112 is used to remove sulfur-containing impurities and / or hydrocarbon impurities in the raw gas.
[0042] In another alternative embodiment, referring to Figure 1 and Figure 2 As shown, the raw gas compressor 111 is a three-stage compressor or a four-stage compressor, and the raw gas compressor 111 is provided with an interstage cooler and an aftercooler.
[0043] In another alternative embodiment, referring to Figure 1 and Figure 2 As shown, the recovery separator 123 includes a middle air inlet, a top outlet, an upper liquid inlet and a bottom outlet; the upper air outlet of the gas-liquid separator 122 is connected to the middle air inlet of the recovery separator 123 through a pipeline; the top outlet of the recovery separator 123 is connected to the middle feed inlet of the dehydration distillation tower 124 through a pipeline; the upper liquid inlet of the recovery separator 123 is connected to the bottom outlet of the dehydration distillation tower 124 through a pipeline; the bottom outlet of the recovery separator 123 is used to discharge the separated liquid.
[0044] In another alternative embodiment, referring to Figure 1 and Figure 2 As shown, the dehydration distillation tower 124 is a packed tower or a plate tower; the reboiler and the top condenser can be inside the dehydration distillation tower or outside the dehydration distillation tower.
[0045] The working process of the carbon dioxide distillation and drying system in this embodiment is as follows:
[0046] Step 1: Compression and purification of raw gas: The raw gas is compressed and purified through compression, desulfurization, dehydrogenation and other processing stages;
[0047] Step 2, precooling and separation: The compressed and purified raw gas is precooled by the refrigerant in the precooler to precipitate some water, and the liquid water is separated and removed in the gas-liquid separator;
[0048] Step 3, recovering carbon dioxide: the raw gas at the gas phase outlet of the gas-liquid separator enters the recovery separator, and uses its own heat to evaporate the carbon dioxide in the liquid of the recovery separator and enter the raw gas;
[0049] Step 4, distillation and dehydration: The raw gas is distilled and separated in a distillation and dehydration tower, and dry gas with a water content of less than 10 ppm is obtained at the top of the dehydration distillation tower. The water-rich distillation tower bottom liquid enters the recovery separator to recover the carbon dioxide therein;
[0050] Step 5, refrigeration: The compressed refrigerant vapor discharged from the refrigeration compressor is condensed into liquid in the condenser and supercooled in the reboiler. The supercooled liquid refrigerant is throttled and cooled by the throttle valve, passes through the top condenser and the precooler in turn, and after providing cooling, it vaporizes and enters the suction port of the refrigeration compressor to complete the refrigeration cycle.
[0051] In a specific example, the raw gas flow rate is 22400 Nm 3 / h, pressure 7kPa (G), temperature 30°C, composition (volume content): CO2-93.58%, N2-2.62%, H2O-3.8%;
[0052] Step 1, compression and purification of raw gas: the raw gas is compressed and purified through compression, desulfurization, dehydrogenation and other processing stages. In this example, the raw gas is compressed to above 4 MPa (G) by the raw gas compressor 01. The raw gas compressor is a 3-stage or 4-stage compressor, and is provided with an interstage cooler and an aftercooler, and is cooled by circulating cooling water;
[0053] Step 2, precooling and separation: The compressed raw gas is precooled to about 10°C by the refrigerant in the precooler, most of the water (about 68%) is precipitated, and the liquid water is separated and removed in the gas-liquid separator;
[0054] Step 3, recovering carbon dioxide: the raw gas at the gas phase outlet of the gas-liquid separator enters the recovery separator, and the heat of the raw gas itself is used to evaporate the carbon dioxide in the liquid of the recovery separator and enter the raw gas. The water content of the remaining liquid reaches 99.97%, and the carbon dioxide content is less than 0.03%. The remaining liquid is discharged as waste liquid;
[0055] Step 4, distillation and dehydration: the raw gas is introduced into a distillation and dehydration tower to achieve distillation separation. In this example, the temperature distribution of the entire dehydration distillation tower decreases from bottom to top, and the lowest temperature is above 3°C. There is no risk of freezing and blocking. The water content of the exhaust gas at the top of the dehydration distillation tower is as low as below 0.1ppm, and the exhaust liquid at the bottom of the dehydration distillation tower contains more than 88% carbon dioxide and only less than 12% water. If this bottom liquid is directly discharged, it will cause a waste of carbon dioxide. This problem can be effectively solved by recovering carbon dioxide in step 3;
[0056] Step 5, refrigeration: The refrigerant vapor discharged from the refrigeration compressor is condensed into liquid by circulating cooling water in the condenser and supercooled in the reboiler. The supercooled liquid refrigerant is throttled and cooled by the throttle valve, passes through the top condenser and precooler in turn, provides cooling capacity, and then vaporizes and enters the suction port of the refrigeration compressor to complete the refrigeration cycle.
[0057] According to the system provided in this embodiment, by inputting the example gas source, a dry gas with a water content of less than 0.1ppm, a carbon dioxide content of about 97.3%, a nitrogen content of about 2.7%, and a temperature of about 3.4°C can be obtained; the energy consumption of the drying and cooling parts excluding the raw gas compressor is about: 112kW of electricity and 130t / h of circulating cooling water (5°C temperature difference, the same below). If the zero-gas compression heat adsorption drying technology is adopted, the drying to a water content of 1ppm, the energy consumption of the drying part is about: 94kW of electricity and 15t / h of circulating cooling water; the dried gas is then cooled to about 3.4°C (the same as the exhaust temperature at the top of the dehydration distillation tower in the example), and the energy consumption of the cooling part is: 90kW of electricity and 105t / h of circulating cooling water; the two together, that is, the energy consumption of the drying and cooling parts using the adsorption drying technology is about: 184kW and 120t / h of circulating cooling water. Compared with the existing adsorption drying technology, the carbon dioxide distillation drying system provided in this embodiment has a significant energy-saving effect while achieving a better drying effect. Calculated in terms of drying and cooling, the energy saving rate of this patented technology is about 38%, and the energy saving rate of the drying part converted to the same conditions is as high as more than 70%.
[0058] Based on the same inventive concept, the present utility model also provides a carbon dioxide purification and liquefaction system, referring to Figure 3 , Figure 4 As shown, the system may include: a carbon dioxide gas source supply system 2, a carbon dioxide distillation and purification system 3 or a carbon dioxide liquefaction system 4 and the above-mentioned carbon dioxide distillation and drying system 1; the carbon dioxide gas source supply system 2 is connected to the compression and purification subsystem 11 through a pipeline; the carbon dioxide distillation and purification system 3 or the carbon dioxide liquefaction system 4 is connected to the top gas outlet of the dehydration distillation tower 124 through a pipeline.
[0059] The description and beneficial effects of the dry carbon dioxide purification and liquefaction system provided in this embodiment can refer to the above-mentioned carbon dioxide distillation and drying system, and the embodiments of the present utility model will not be repeated here.
[0060] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A carbon dioxide distillation drying system, characterized in that: include: Compression and purification subsystem, distillation and dehydration subsystem and refrigeration subsystem; The distillation and dehydration subsystem includes: a precooler, a gas-liquid separator, a recovery separator, a dehydration distillation tower, a reboiler and a tower top condenser; One end of the compression and purification subsystem is externally connected to the raw gas pipeline, and the other end is connected to the precooler; the precooler, the gas-liquid separator, the recovery separator and the dehydration distillation tower are connected in sequence; the top of the dehydration distillation tower is connected to the top condenser, the bottom of the dehydration distillation tower is connected to the reboiler, and the recovery separator is connected to the bottom of the dehydration distillation tower; the refrigeration subsystem is connected to the cold sides of the precooler and the top condenser through pipelines to form a cooling circuit.
2. The system according to claim 1, characterized in that The refrigeration subsystem includes: a refrigeration compressor, a condenser and a throttle valve; the refrigeration compressor, the condenser, the throttle valve, the cold side of the tower top condenser and the cold side of the precooler are connected in sequence through pipelines to form a cooling circuit.
3. The system according to claim 2, characterized in that The refrigeration compressor, the condenser, the throttle valve, the hot side of the reboiler, the cold side of the top condenser and the cold side of the precooler are connected in sequence through pipelines to form a closed loop.
4. The system according to claim 1, characterized in that The compression and purification subsystem comprises: a raw gas compressor; one end of the raw gas compressor is externally connected to a raw gas pipeline, and the other end is connected to the precooler.
5. The system according to claim 4, characterized in that The compression and purification subsystem further includes: a purification device located between the raw gas compressor and the precooler, and the purification device is used to remove sulfur-containing impurities and / or hydrocarbon impurities in the raw gas.
6. The system according to claim 4 or 5, characterized in that: The raw gas compressor is a three-stage compressor or a four-stage compressor, and the raw gas compressor is provided with an interstage cooler and an aftercooler.
7. The system according to claim 1, characterized in that The recovery separator comprises a middle air inlet, a top outlet, an upper liquid inlet and a bottom outlet; The upper gas outlet of the gas-liquid separator is connected to the middle gas inlet of the recovery separator through a pipeline; the top outlet of the recovery separator is connected to the middle feed inlet of the dehydration distillation tower through a pipeline; the upper liquid inlet of the recovery separator is connected to the bottom outlet of the dehydration distillation tower through a pipeline; the bottom outlet of the recovery separator is used to discharge the separated liquid.
8. The system according to any one of claims 1 to 5 and 7, characterized in that: The dehydration distillation tower is a packed tower or a plate tower.
9. The system according to claim 6, characterized in that The dehydration distillation tower is a packed tower or a plate tower.
10. A carbon dioxide purification and liquefaction system, characterized in that: include: A carbon dioxide gas source supply system, a carbon dioxide distillation and purification system or a carbon dioxide liquefaction system and a carbon dioxide distillation and drying system as claimed in any one of claims 1 to 9; The carbon dioxide gas source supply system is connected to the compression and purification subsystem through a pipeline; the carbon dioxide distillation and purification system or the carbon dioxide liquefaction system is connected to the top gas outlet of the dehydration distillation tower through a pipeline.