The system can provide air conditioning supply function and dry ice production system with carbon dioxide in air as gas source

Abstract

Companies and institutions around the world are researching and developing CCU technology, but in addition to the cost of recovering carbon dioxide gas, there are many problems to be solved, such as what kind of valuable material it is converted into, the conversion cost, the equipment cost, and whether it is commercially viable. The present invention proposes a CCU system with future potential and high added value that can be used for air conditioning supply. A dry ice production system, in a system composed of a wet TSA carbon dioxide gas separation and concentration device, a saturated steam generator, a gas cooling device, a gas compression device, a dehumidification device, a gas liquefaction device and a refrigerator, a gas purification tank, and a dry ice production device, recovers the waste heat generated in each device as a heat source for the separation and concentration device, and uses the non-liquefied gas during purification after liquefaction for purging of the separation and recovery concentration device, and by recovering the non-desublimation gas of the dry ice production device, high energy efficiency, compact structure, and the ability to provide both air conditioning supply function and carbon dioxide in the air as a gas source are achieved.

Description

Technical Field

[0001] This invention relates to an energy-saving carbon dioxide gas separation, recovery, concentration, compression, cooling, dehumidification, liquefaction and dry ice production system, as well as a wet TSA carbon dioxide separation and concentration device. The system can also provide air conditioning function and uses carbon dioxide in the air as raw material. Background Technology

[0002] Global efforts are underway to minimize carbon dioxide emissions from industry, vehicles, and households in response to global warming. Examples include replacing energy-intensive equipment with energy-efficient appliances and replacing fossil fuels with renewable energy sources such as solar and wind power. Furthermore, research and development are underway on carbon dioxide capture and storage (CCS) technology—capturing unavoidable carbon dioxide and storing it underground or in the deep sea; CO2-EOR (enhanced oil recovery) technology; and technologies that absorb and fix carbon dioxide using compounds in concrete or rock. To date, technologies for efficiently recovering and concentrating carbon dioxide, as described in Patent Document 1, have been considered suitable for sources of high-concentration gases, such as power plants and waste incineration facilities, and for sources of heat loss that can be recovered and concentrated. Moreover, to improve the liquefaction efficiency of the recovered and concentrated gas, Patent Document 2 discloses a device that uses the heat of compression from a compressor as a regenerative heat source for a carbon dioxide dehumidification device, thereby improving energy efficiency.

[0003] Carbon capture and utilization (CCU) technology, which utilizes recovered carbon dioxide as a resource, has been put into practical use, for example, by reusing it as a feedstock for urea or polycarbonate resin. However, this accounts for only a small portion of total carbon dioxide emissions. In recent years, various countries and institutions have also been researching and developing renewable fuels that convert recovered carbon dioxide gas into liquid or gaseous fuels.

[0004] Furthermore, particularly overseas, Direct Air Capture (DAC) technology, which directly separates and recovers carbon dioxide from the atmosphere, has been developed and tested in patent documents 3 and 4. The advantages of DAC are: (1) it can target dispersed and mobile emission sources, such as vehicles and aircraft; (2) it can also target carbon dioxide emitted in the past; and (3) the installation location of the recovery device is not limited by the emission source, and the carbon dioxide feedstock can be obtained near the plant where it needs to be reused. Due to these characteristics, large-scale verification tests are underway in Europe and the United States.

[0005] To reduce carbon dioxide emissions, it is also necessary to pay attention to the carbon dioxide emissions generated from the recovery, concentration, and liquefaction of the energy required. To this end, Patent Document 3 discloses all available energy sources, from waste heat from combined heat and power plants and various renewable energy sources to geothermal and nuclear power plant waste heat.

[0006] Patent Document 4 discloses a method that uses a heat pump to inject steam into a carbon dioxide adsorption structure for desorption. An evaporator coil installed downstream of the adsorption structure recovers the heat from the desorbed gas and the condensate, while a condenser coil installed upstream of the adsorption structure serves as the heat source for generating desorption steam. Another method discloses a method where high-humidity carbon dioxide gas desorbed from the adsorption structure is recompressed and heated, then fed into a kettle reboiler to generate desorption steam through heat exchange, and the condensate from the desorbed gas is recovered. Patent Document 6 discloses a heat pump that recovers heat from wastewater to generate steam; this technology has recently been put into practical use.

[0007] Carbon dioxide gas has been in high demand in welding, medical, food storage and other applications, and its feedstock gas is recycled and used as a byproduct in petrochemical plants and ammonia synthesis plants.

[0008] It is estimated that Japan will sell 1.1 million tons of carbon dioxide gas products in 2021, with the largest use being welding (33%) and the second largest use being dry ice (32%).

[0009] Liquefied carbon dioxide gas products have different quality standards depending on the application, and the purification and dehumidification processes to ensure quality also contribute to increased costs. As a quality standard, JIS K1 106 specifies one to three types of quality for liquefied carbon dioxide, including purity and moisture content. JIS Z3253 specifies quality standards for industrial gases such as those used in welding.

[0010] In recent years, petrochemical plants and ammonia synthesis plants in Japan, which have long used carbon dioxide (CO2) recovery as a source, have downsized and relocated overseas, leading to a shortage of CO2 sources. Since 2010, imports from overseas have increased dramatically, causing a sense of crisis within the industry, which is currently researching countermeasures. As a countermeasure, verification trials are being conducted in various regions, attempting to use exhaust gases from steel mills, power plants, and waste incineration facilities as CO2 recovery sources. However, because combustion gases contain many impurities such as NOx, SOx, and dust, pretreatment is crucial. Currently, many problems exist, such as ensuring the purity of the recovered CO2, recovery costs, and transportation costs. Furthermore, the location of CO2 collection points on remote islands and in remote areas also presents the problem of increased CO2 emissions during transportation.

[0011] To date, gas sources such as petrochemical plants have been considered safe due to the recovery and utilization of carbon dioxide. However, concerns about environmental pollution from vehicle electrification and plastic waste are driving resource recycling and a rethinking of fuels, production methods, and materials with less environmental impact, leading to the anticipated scarcity of these gas sources. In the near future, product carbon dioxide recovery sources should also be replaced by renewable resources.

[0012] In Japan, the dry ice market comprises 350,000 tons annually, with approximately 300,000 tons used for transportation and express delivery. In recent years, the global push for vaccination to prevent the novel coronavirus pandemic, coupled with the need for ultra-low temperature storage of vaccines, has increased the demand for dry ice for transportation. The growing demand for dry ice as a refrigerant is also increasing due to the growing need for home delivery of refrigerated and frozen foods. Dry ice demand fluctuates seasonally, with annual summer shortages necessitating the import of 26,000 tons from abroad. While carbon dioxide emissions from domestic petrochemical plants and other facilities are calculated based on the source of recovery, imported dry ice is calculated based on domestic emissions, thus increasing overall carbon dioxide emissions.

[0013] In regions with long periods of high temperatures, such as Okinawa in Japan, the Philippines, Vietnam, India, Mexico, and Brazil, dry ice is needed year-round as a refrigerant. However, many of these regions are far from sources of carbon dioxide, so specialized gas transport vehicles, tank trucks, carbon dioxide cylinders, or dry ice must be used to transport the gas to the areas in need, which increases carbon dioxide emissions.

[0014] Regarding improving dry ice production efficiency, Patent Document 7 discloses a method for increasing the dry ice output of an apparatus for producing dry ice from liquid carbon dioxide in a storage tank. Patent Document 8 discloses an apparatus for recovering and liquefying unsublimated (dry-ice-forming) carbon dioxide gas in an apparatus for producing dry ice using liquefied carbon dioxide.

[0015] Dry ice is a refrigerant that utilizes the latent heat of carbon dioxide. Unlike other liquefied carbon dioxide products, it does not need to be as pure. Because dry ice is used for food storage, transportation, and other refrigeration purposes, if it is made from carbon dioxide gas recovered from the atmosphere, then the gas released into the atmosphere from its use will not have an environmental impact. In other words, establishing a market distribution system for renewable carbon dioxide would be a measure to prevent global warming.

[0016] Existing technical documents

[0017] Patent documents

[0018] Patent Document 1: Japanese Patent Application Publication No. 6-99034

[0019] Patent Document 2: Japanese Patent Application Publication No. 2010-266155

[0020] Patent Document 3: Japanese Patent Application Publication No. 2018-23976

[0021] Patent Document 4: Japanese Patent Publication No. 2017-528318

[0022] Patent Document 5: Japanese Patent No. 6510702

[0023] Patent Document 6: Japanese Patent Application Publication No. 2007-232357

[0024] Patent Document 7: Japanese Patent Application Publication No. 2006-193377

[0025] Patent Document 8: Japanese Patent Application Publication No. 2016-204234

[0026] Patent Document 9: Japanese Patent Application No. 2021-211907 Summary of the Invention

[0027] The problem that the invention aims to solve

[0028] Companies and institutions worldwide are researching and developing CCU technology, but beyond the cost of carbon dioxide recovery, many issues remain to be addressed, such as what valuable commodity to convert it into, conversion costs, equipment costs, and commercial viability. Among the various possible CCU technologies, it is hoped that the CCU system will serve as a pioneer in practical application and be launched and promoted in the market more quickly.

[0029] Therefore, this system does not need to be installed in facilities that emit large amounts of carbon dioxide gas, such as typical power plants or petrochemical plants. Instead, it is designed to be a relatively compact system that can be implemented on a small-scale plant scale in places that utilize recovered carbon dioxide gas. It achieves high energy efficiency through the mutual utilization of waste heat and exhaust gas from various devices throughout the system. It also provides air conditioning ventilation, separation, concentration, liquefaction of carbon dioxide gas in the air, and dry ice production system.

[0030] As prior art, Patent Document 1 discloses a plant example for separating and concentrating liquefied carbon dioxide from a combustion furnace. Carbon dioxide gas separation and concentration methods include the TSA method, PSA method, and PTSA method. A method for improving the recovery rate and purity of liquefied carbon dioxide by refluxing the liquefied unliquefied gas is disclosed, but no method for improving energy efficiency is mentioned.

[0031] Because compression increases the partial pressure of water vapor, easily producing condensate, the recovered carbon dioxide gas needs to be cooled and dehumidified by condensation. Due to quality requirements, it can also be dehumidified to a lower dew point temperature using absorption or adsorption dehumidifiers (such as PSA or TSA methods). Patent Document 2 relates to energy-saving equipment for compressing, cooling, and liquefying recovered carbon dioxide gas, and discloses a method for improving energy efficiency by utilizing the heat of return refrigerant from the carbon dioxide liquefaction refrigeration coil in the pre-liquefaction process for cooling and dehumidification. However, it does not consider the energy efficiency of the preceding carbon dioxide gas separation and concentration unit or the utilization of waste heat generated in the compression liquefaction unit.

[0032] In Patent Document 3, in the DAC technology, in addition to cogeneration waste heat, solar thermal energy, biomass, geothermal energy, and nuclear energy, process heat generated in the recovery and concentration process is also utilized as a heat source for separating and concentrating carbon dioxide gas, but no specific method is disclosed. In any case, implementation is limited to locations and environments where heat source energy is available.

[0033] Patent document 4 relates to DAC technology. It discloses a method for adsorbing carbon dioxide gas in a carbon dioxide gas separation and concentration device. During desorption, the carbon dioxide gas is heated by a heat exchanger element assembled in the adsorption structure, and simultaneously recovered by superheated steam desorption. During adsorption, a cooling fluid flows through the heat exchanger element, cooling while simultaneously adsorbing the carbon dioxide gas. The heat capacity of the heat exchanger element itself hinders the overall system's thermal efficiency and complicates the process when switching between adsorption and desorption. Another example is disclosed where a steam generating heat exchanger and a steam condensing heat exchanger are connected to a heat pump to recover the condensation heat from steam generation. A method is also disclosed to recompress the aforementioned carbon dioxide-containing desorbed gas to increase the temperature and partial pressure of water vapor, feeding it into a kettle reboiler as a heat source. Water vapor for desorption is generated through a heat exchanger, and the condensate is reused. Furthermore, to prevent thermal degradation of the amine adsorption structure and improve the purity of the recovered gas, repeated vacuum evacuation and pressurization operations are required, which consumes energy and complicates the equipment.

[0034] Patent document 5 discloses a wet TSA method for separating and concentrating carbon dioxide gas. In its method for recovering and concentrating carbon dioxide gas, a gas circulation path is constructed connecting the inlet and outlet of the desorption zone. A blower and a steam generator heater are installed in the loop. While circulating the gas in the loop, water is supplied to the heat transfer surface of the steam generator heater to heat it and supply saturated steam using boiling evaporation pressure. This method for recovering and concentrating carbon dioxide gas involves housing and rotating a honeycomb rotor with carbon dioxide adsorption function within a sealed housing having at least an adsorption zone and a desorption zone. The method includes: in the adsorption zone, contacting the honeycomb rotor with a mixed gas containing carbon dioxide gas in a wet state, adsorbing carbon dioxide gas while vaporizing and cooling; and in the desorption zone, introducing saturated steam into the honeycomb cells that have adsorbed carbon dioxide gas to desorb the carbon dioxide gas. While it is expected that reducing the oxygen concentration in the circulating gas will prevent thermal oxidative degradation of the amine adsorbent material, conversely, insufficient desorption due to the partial pressure of carbon dioxide gas leads to a reduced recovery rate.

[0035] Patent 6 discloses a heat pump type steam and hot water generator that can recover heat from waste hot water and use a heat pump to generate and supply steam and hot water. Engineers can easily imagine the possibility of using steam in a carbon dioxide gas separation and concentration device, but how to utilize steam requires creativity.

[0036] Regarding devices for improving dry ice production efficiency, Patent Document 7 already exists. When liquefied carbon dioxide gas is released under atmospheric pressure, its latent heat of vaporization cools and sublimates the carbon dioxide gas, thereby generating dry ice. However, the generated dry ice only accounts for about 40% of the released carbon dioxide gas, with the remainder being vaporized. This patent discloses that by subcooling the liquefied carbon dioxide before release, the yield can be increased to 60-70%. Patent 8 discloses a technique for recovering unsublimated carbon dioxide gas during the dry ice production process and recompressing and liquefying it to prevent gas loss.

[0037] Although Patent Document 9 discloses a method for separating and concentrating carbon dioxide gas from air using DAC technology and wet TSA, it does not disclose the use of recovered carbon dioxide gas or the desorption heat source of the carbon dioxide separation and concentration device. Without solving these two key issues, CCU technology will not be widely promoted.

[0038] Methods for solving problems

[0039] Liquefied carbon dioxide (LCC) products are standardized and can be purified to higher purities than commercially available products, depending on the application. When carbon dioxide gas is used in medical, food, chemical, or welding applications, it can affect the quality of the final product, thus requiring specific quality standards; purity, water content, etc., are regulated in JIS (Joint Standards for Chemicals). However, even dry ice, another CCC product used as a refrigerant, lacks JIS standards, and manufacturers' quality guidelines stipulate it should be white and odorless. While CCC gas must be dehumidified, in dry ice production, moisture is added to solidify it into snow-like ice, thus purity requirements are less stringent. Oxygen, nitrogen, and water content may be considered impurities in CCC gas, but these issues do not exist in dry ice.

[0040] Therefore, the inventors have developed a small, compact, and energy-saving carbon dioxide gas separation and concentration dry ice production system, aiming to realize a high-value-added system that can use the treated air for air conditioning. The system utilizes a rotor with carbon dioxide gas adsorption function to recover carbon dioxide gas from the air, and recovers the compression waste heat, cooling waste heat, dehumidification waste heat, gas liquefaction refrigeration machine waste heat, and air conditioning waste heat generated in the compression and liquefaction process of the recovered carbon dioxide gas, and uses them as a heat source for the desorption carbon dioxide gas separation and concentration device.

[0041] This invention relates to a carbon dioxide gas separation, concentration, cooling, liquefaction, and dry ice production system, comprising a wet TSA carbon dioxide gas separation and concentration unit, a saturated steam generator, a cooling and dehumidification unit, a gas compression unit, an adsorption dehumidification unit, a cooling unit, a gas liquefaction unit, a refrigeration unit, a cooling tower, a liquefied carbon dioxide purification tank, and a dry ice production unit. In the dry ice production system, unsublimated gas produced during dry ice production is recovered to the gas compression unit. The wet TSA carbon dioxide gas separation and concentration unit ensures that the rotor with carbon dioxide gas adsorption capacity has at least... The carbon dioxide gas is loaded into a highly insulated "purge and recovery block" with a treatment zone, a purging zone, and a desorption zone in the order of rotation. The block is then contained and rotated into its respective sealed housing. In the treatment zone, air is introduced while the rotor is wet to vaporize and cool it, while carbon dioxide gas is adsorbed. In the purging zone, unliquefied gas from the liquefied carbon dioxide purification tank is introduced to purge and discharge the air contained in the rotor gaps. In the desorption zone, saturated steam generated by the steam generator is introduced under steam generation pressure, and the condensation heat of the steam is used to desorb and recover the concentrated carbon dioxide gas.

[0042] As a method to further improve energy efficiency, this invention relates to a wet TSA carbon dioxide gas separation and concentration device. In this device, rotors with carbon dioxide adsorption capacity are sequentially assembled in the direction of rotation into highly insulated "purge and recovery blocks" comprising a processing zone, a purging zone, multiple recovery zones (at least one stage), and a desorption zone. These blocks are housed and rotated within their respective sealed housings. In the processing zone, air is introduced to vaporize and cool the rotor while it is wet, simultaneously adsorbing carbon dioxide gas. In the purging zone, unliquefied gas from a liquefied carbon dioxide purification tank is introduced to expel air contained in the rotor gaps. Saturated steam is introduced into the desorption zone, where the condensation heat of the steam desorbs high-concentration carbon dioxide gas. This desorbed gas is then introduced into the recovery zone upstream of the rotational stage and continues to be recovered through multiple recovery zones, including the recovery zone further upstream of the rotational stage and the upstream side of the rotational stage. Replacing the wet carbon dioxide separation and concentration device in the aforementioned dry ice production system with this device can save even more energy.

[0043] By utilizing the treated outlet air with a lower carbon dioxide concentration as air supply for air conditioning, the increased added value of the system's promotion is considered. Air from the treated area of ​​the wet TSA carbon dioxide gas separation and concentration unit is cooled and dehumidified using cooling coils before being used as air supply for air conditioning. The wastewater from the cooling coils is recycled and used as water for the saturated steam generator, thereby achieving energy savings in air conditioning, increasing the added value of the dry ice production system of this invention, and saving water.

[0044] To further improve the energy efficiency of the entire system, the recovery and utilization of waste heat generated inside and near the system were studied. The saturated steam generator is a heat pump steam generator that utilizes waste heat to recover waste heat from the refrigeration unit that cools and liquefies the compressed heat of carbon dioxide gas and the nearby refrigeration and air conditioning unit, and supply it to the steam generating heat pump to produce saturated steam.

[0045] Energy saving through low dew point dehumidification of the recovered gas was also considered. By introducing compressed high-temperature gas from a gas compression device into the regeneration zone of a honeycomb rotor adsorption dehumidifier with a treatment zone and a regeneration zone to desorb the adsorbed water on the rotor, and by cooling and dehumidifying the outlet gas through a cooling coil before introducing it into the treatment zone for adsorption and dehumidification, energy saving through low dew point dehumidification can be achieved.

[0046] The effects of the invention

[0047] The dry ice production system of the present invention, which provides air conditioning ventilation and uses carbon dioxide from the air as a gas source, consists of a wet TSA carbon dioxide gas separation and concentration unit, a saturated steam generator, a cooling and dehumidification unit, a gas compression unit, an adsorption dehumidification unit, a cooling unit, a gas liquefaction unit, a refrigeration unit, a liquid carbon dioxide purification tank, and a dry ice production unit. Any carbon dioxide gas separation, concentration, and liquefaction unit requires compression, cooling, and liquefaction processes, each of which consumes energy and generates corresponding waste heat. In the carbon dioxide gas compression and liquefaction process, a large amount of heat of compression and latent heat of cooling and liquefaction are generated. The heat of compression, as well as the latent heat of cooling and liquefaction, are typically released into the atmosphere through radiators such as cooling towers. By recovering this heat and using it as energy for separating and concentrating carbon dioxide from the air, the system can be installed anywhere far from large carbon dioxide sources and available waste heat sources.

[0048] When liquefied carbon dioxide enters the purification tank, it still contains unliquefied gas. However, because the unliquefied gas contains impurities from the air, it must be discharged to improve purity and reduce resistance to the liquefied gas entering the purification tank. This invention, by using this unliquefied gas as the purification gas in a wet TSA carbon dioxide gas separation and concentration system, effectively increases the concentration of the recovered gas. Furthermore, in a dry ice production system, by returning the unsublimated gas generated during dry ice production to the aforementioned gas compression device for recovery, the overall system's recovery efficiency and energy efficiency can be improved.

[0049] The wet TSA carbon dioxide gas separation and concentration unit has a processing zone, a purging zone, and a desorption zone. In the processing zone, the rotor is brought into contact with air containing carbon dioxide in a wet state, and carbon dioxide is adsorbed while being vaporized and cooled. Meanwhile, unliquefied gas from the LPG purification tank is introduced into the purging zone to purge air contained in the exhaust rotor gaps as it rotates and moves to the desorption zone. This prevents air from migrating to the desorption zone, increases the concentration of recovered carbon dioxide, and prevents thermal oxidation and deterioration of the adsorbent material in the desorption zone. In the desorption zone, saturated steam at approximately 100°C is introduced at boiling pressure to desorb and recover the adsorbed carbon dioxide. Approximately 100°C means that the boiling point of water varies with pressure; therefore, a fluctuation of a few degrees Celsius is expected depending on the resistance to introducing saturated steam into the desorption zone and the gas pressure.

[0050] To further improve the energy efficiency of a wet TSA carbon dioxide gas separation and concentration unit, a structure has been invented that sequentially divides the rotor zone into a processing zone, a purging zone, multiple recovery zones (including a primary recovery zone), and a desorption zone, arranged in the direction of rotation. Unliquefied gas from the liquefied gas purification tank is introduced into the purging zone to expel air contained in the rotor gaps. Saturated steam at approximately 100°C is introduced into the desorption zone to desorb high-concentration carbon dioxide gas using the condensation heat of the steam, similar to the previous method. However, a recovery zone is provided between the purging and desorption zones. The desorbed outlet gas passes through the recovery zone in front of the desorption zone in the direction of rotation to recover the enthalpy of the desorbed outlet gas. This achieves the effect of preheating the rotor before desorption and reducing the cooling and dehumidification load in subsequent processes by precooling the recovered gas. Furthermore, it reduces the risk of air entering the desorption zone.

[0051] Multiple recovery zones, or more than one, can be set up in the recovery zone. The gas exiting the desorption zone is introduced into recovery zone 1 in the front stage of the rotation direction, and then it passes through multiple recovery zones sequentially towards recovery zone 2 in the front stage of the rotation direction and the front stage side of the rotation direction for recovery. The total channel length of the recovery zone can be assumed to be 200-400 mm, but based on the understanding of the heat exchange efficiency of rotary heat exchangers, the correct number of stages depends on the rotor width and the flow velocity. For example, when the number of units is 190 and the rotor width is 50 mm, if the ideal total channel length is 200 mm, four channels can be assumed, but this can be determined through testing and evaluation of economy and effectiveness.

[0052] On the other hand, the carbon dioxide concentration of the air passing through the treatment zone decreases, and due to the evaporative cooling effect, the temperature remains almost unchanged, but the absolute humidity increases. This air is cooled and dehumidified by cooling coils, enabling the use of high-quality air with lower carbon dioxide concentrations for air conditioning supply, which is expected to improve the intellectual productivity of residents. The wastewater from the cooling coils is recycled and sent to a saturated steam generator, further improving the system's introduction efficiency and economy, and reducing initial and operating costs.

[0053] The carbon dioxide gas to be liquefied and recovered needs to be compressed and cooled. If it is compressed to 6.4 MPa through multi-stage compression, the gas temperature reaches about 130°C. Steam can also be generated by heat exchange with this gas. However, if the amount of steam generated is insufficient, the waste heat from the cooler, liquefier, refrigeration unit, and, if necessary, the air conditioner of nearby facilities in the system of this invention can be recovered as the heat source for the steam generating heat pump to provide desorption energy for the carbon dioxide gas separation, recovery, and concentration device.

[0054] Low dew point dehumidification of recovered gas can be used in combination with a rotary adsorption dehumidifier. In the regeneration zone of a honeycomb rotary adsorption dehumidifier, which has a treatment zone and a regeneration zone, compressed high-temperature gas from a gas compression unit is introduced to desorb the adsorbed moisture from the rotor. As the gas passes through and its temperature decreases due to the heat of desorption, and its dew point temperature (absolute humidity) increases, the gas in this zone is cooled and dehumidified by the next cooling coil. Furthermore, the recovered gas, after being dehumidified to a lower dew point temperature in the treatment zone of the rotary adsorption dehumidifier, is introduced into the compressor in the next stage.

[0055] This dehumidification method can lower the dew point temperature of the recovered gas to a negative dew point below the temperature of the cooling coil, thus achieving the same dehumidification effect as traditional PSA, TSA, and PTSA methods, while utilizing residual heat in the system for regeneration. The honeycomb rotor dehumidifier is a known form of TSA dehumidification, but combining it in this way with the system of this invention helps improve the overall energy efficiency of the system.

[0056] As described above, the system of the present invention generates saturated steam from the waste heat produced in the recovery system, which becomes the desorption energy for adsorbing carbon dioxide gas, thus saving energy for the entire system. Of course, the system requires electricity to operate, but in periods and regions with high demand for dry ice and abundant sunshine, this system is well-suited for photovoltaic power generation. In hot regions, the system can also utilize the heat from cooling waste gas, and by supplying air with treated low-carbon dioxide gas, high-quality air conditioning can be achieved without excessive ventilation. If the air conditioning return air or waste gas is used as treated air, the higher concentration of carbon dioxide gas compared to the outside air can be expected to increase the recovery rate. If the return air is used for treatment, energy-saving effects can also be expected by recovering the enthalpy of the return air.

[0057] Furthermore, the system of this invention does not rely on carbon dioxide gas sources or waste heat sources found in conventional technologies, allowing for the establishment of small to medium-sized systems. Therefore, it can be distributed to various dry ice demand areas, reducing carbon dioxide emissions during the transportation of dry ice and carbon dioxide gas, and improving overall operational efficiency. In addition, the heat capacity of the carbon dioxide gas separation and concentration device of this invention is far lower than that of the traditional absorbent method. The entire system can be easily started, stopped, and deactivated according to the needs of dry ice production, resulting in a corresponding reduction in heat loss.

[0058] As mentioned above, combining dry ice production with energy-efficient air conditioning that uses air with low carbon dioxide concentrations can promote its widespread application as a CCU technology and accelerate the reduction of carbon dioxide emissions from plants such as petrochemical plants. Attached Figure Description

[0059] Figure 1This is a basic flow chart of the air-based carbon dioxide gas source dry ice production system capable of air conditioning and air supply according to the first embodiment of the present invention.

[0060] Figure 2 This is a detailed diagram of the carbon dioxide gas separation and concentration apparatus according to the first embodiment of the present invention.

[0061] Figure 3 This is a basic flow chart of the air-based carbon dioxide gas source dry ice production system capable of air conditioning and air supply according to the second embodiment of the present invention.

[0062] Figure 4 This is a detailed diagram of the carbon dioxide gas separation and concentration apparatus according to the second embodiment of the present invention.

[0063] Figure 5 This is a schematic cross-sectional diagram illustrating the processing zone, purging zone, second recovery zone, first recovery zone, and desorption zone of the carbon dioxide gas separation and concentration device according to the second embodiment of the present invention.

[0064] Figure 6 This is a schematic cross-sectional diagram illustrating the principle of the carbon dioxide gas separation and concentration device according to the third embodiment of the present invention.

[0065] Figure 7 This is a schematic diagram illustrating the principle of the honeycomb rotor dehumidification device according to the second embodiment of the present invention.

[0066] Figure 8 This is a flowchart of a small-scale experimental setup for actual prototype testing.

[0067] Figure 9 This is a schematic diagram of the actual application of a medium-sized box.

[0068] Figure 10 This is a schematic diagram of the actual application of the four units of the medium-sized box. Detailed Implementation

[0069] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the figures, components, etc., marked with the same symbols have the same or similar structures, therefore repeated descriptions of them are omitted. Furthermore, in each figure, components, etc., that do not require further explanation are omitted.

[0070] This invention is based on the process of a compact and energy-efficient rotor-type wet TSA (thermal swing) method for separating and concentrating carbon dioxide in air, which has been researched and developed to date. First, the principle and advantages of the wet TSA method are explained. The wet TSA method uses saturated steam instead of superheated steam to desorb carbon dioxide gas and utilizes the condensation heat of the saturated steam to desorb and concentrate the carbon dioxide gas for recovery. Since it does not use heated air or gas for desorption as in the traditional dry TSA method, not only can high concentration recovery be achieved, but water vapor also condenses during desorption, leaving water on the inner surface of the honeycomb structure. Carbon dioxide gas is adsorbed while the adsorption zone evaporates and cools, so the rotor cools rapidly immediately after desorption. Simultaneously, the heat from the adsorbed carbon dioxide gas is dissipated to suppress temperature rise. Therefore, compared with the traditional dry TSA method and the superheated steam TSA method, the carbon dioxide adsorption performance and energy-saving effect are significantly improved.

[0071] Furthermore, by using saturated steam at around 100°C without air for desorption, the thermal oxidation and deterioration of the amine adsorbent material can be effectively prevented. Additionally, when the material is rotated and moved to the treatment zone immediately after desorption at a high temperature and comes into contact with air, the surface of the adsorbent material is covered with condensate, thus avoiding direct contact with oxygen. It also experiences rapid cooling through the vaporization cooling effect generated by the passage of treatment air, thereby preventing thermal oxidation and deterioration.

[0072] The present invention is inventive in further preventing the thermal oxidative degradation of the adsorbent material in the above-mentioned wet TSA method, thereby improving the recovery rate and recovery concentration, and improving energy efficiency.

[0073] [Implementation Method 1]

[0074] Figure 1 This is the entire system of Implementation Method 1. Since the treated gas is air or air conditioning air, no special pretreatment is required; a dust filter similar to those used in ordinary air conditioners is sufficient. Water-soluble impurities and fine dust are removed and discharged along with condensate from the cooling coils in the system. If necessary, an activated carbon deodorizing filter can be installed at the treated air intake.

[0075] first, Figure 2 A carbon dioxide gas separation and concentration device is described in detail. The rotor 1, which adsorbs carbon dioxide gas, is driven and rotated by a rotor drive motor 2 via a belt 3. Larger equipment may also use a chain drive. When processing air is introduced into the processing zone 4 of the rotor via a blower 7, the humid rotor is vaporized and cooled while adsorbing carbon dioxide gas, and the heat of adsorption is also cooled and removed simultaneously.

[0076] When the rotor rotates to purge zone 6, unliquefied gas from the liquefied carbon dioxide purification tank is introduced, and the air contained in the rotor gaps is purged and discharged to the treatment zone side. This purging prevents air from mixing with the recovered gas, thereby increasing the recovery concentration, while simultaneously preventing oxygen from entering the high-temperature desorption zone, thus avoiding thermal oxidation and deterioration of the adsorbent material and improving its durability. Allowing carbon dioxide gas with a higher concentration than air to pass through and be adsorbed before desorption is expected to increase the recovery rate. The purge gas can pass through from either direction to purge the air in the rotor gaps, but if the purge gas is discharged to the treatment zone inlet side and merged with the treatment air, even if an excess of purge gas is discharged, resulting in a relatively high concentration of carbon dioxide gas, it will be re-adsorbed in the treatment zone and thus not wasted.

[0077] When the rotor rotates to desorption zone 5-1, saturated steam is introduced at the steam generation pressure from the saturated steam generator. Carbon dioxide gas is desorbed under the action of condensation heat, and condensate remains in the rotor. The mixture of desorbed carbon dioxide gas and water vapor passes through... Figure 1 The cooling coil 10-1 is used for cooling and dehumidification. Then, the cooled and dehumidified recovered gas is introduced into the compression unit 11-1, where it is pressurized and heated. Since carbon dioxide gas is difficult to liquefy in a single-stage compression, the heated gas is further cooled in the cooling coil 10-2 before entering the second-stage compressor 11-2, where it is pressurized to approximately 4 MPa. Figure 1 Not shown in the figure, but further cooled and pressurized to approximately 6.4 MPa in the third-stage compressor. The finally pressurized gas is then recooled, dehumidified to a low dew point temperature by an adsorption dehumidifier 13, and then liquefied to below the liquefaction temperature in a liquefier 15.

[0078] Higher pressures make carbon dioxide gas easier to liquefy, but this increases compression energy, the amount of impurities dissolved in the liquefied gas increases, and purity decreases. Conversely, lower pressures require cooling to a lower liquefaction temperature, increasing the cooling load and reducing the COP (coefficient of performance) of the refrigeration unit, resulting in a trade-off between increased energy consumption and refrigeration unit performance. The liquefied carbon dioxide is sent to a purification tank where unliquefied gas is extracted and stored to improve its purity. The extracted gas is used to purge the aforementioned separation and concentration unit.

[0079] The amount of unliquefied gas extracted from the purification tank must be sufficient to adequately purge any remaining amount that has migrated within the rotor gaps. Insufficient quantity will result in air contamination of the recovered gas. Even an excess will not be wasteful, as the unliquefied gas passing through the purge zone will merge with the processed air and undergo adsorption again in the processing zone. Since the volume of the purge gas fluctuates due to variations in temperature and humidity, as well as the adsorption of carbon dioxide, it is practical to measure and adjust the concentration of carbon dioxide at the 5-1 gas outlet during purge.

[0080] The recovered gas is heated to above 100°C by compressors 11-1 and 11-2. This heat can be used to generate saturated steam. However, if the heat alone is insufficient to generate desorption energy, the waste heat from cooling and dehumidification, compression, and latent heat of liquefaction used in liquefaction can be recovered into a steam-generating heat pump to produce saturated steam, which is then introduced into the desorption zone of the aforementioned carbon dioxide separation and concentration unit. With this configuration, the separation and concentration of carbon dioxide in the air can be achieved by recovering and utilizing the waste heat generated during the compression, cooling and dehumidification, cooling, and liquefaction processes of the separated and concentrated carbon dioxide gas. This results in a more energy-efficient and compact air-source dry ice production system than conventional technologies.

[0081] [Implementation Method 2]

[0082] Figure 3 This is an overall system diagram of Embodiment 2. In the aforementioned wet TSA method, a novel configuration further prevents thermal oxidative degradation of the adsorbent material, improving recovery rate and concentration, and enhancing energy efficiency. Details of the carbon dioxide gas separation and concentration apparatus will first be provided in... Figure 4 The rotor 1, which can adsorb carbon dioxide gas, is divided into a treatment zone 4, a purging zone 6, a second-stage recovery zone 5-3, a first-stage recovery zone 5-2, and a desorption zone 5-1 in the direction of rotation, and is driven by a rotor drive motor 2 via a belt 3.

[0083] When air is introduced into the rotor's processing zone 4 by the blower 7, the humid rotor simultaneously adsorbs carbon dioxide gas and vaporizes and cools the water, and the resulting adsorption heat is also removed by cooling. In the rotating gas purging zone 6, unliquefied gas from the liquefied carbon dioxide purification tank 16 is introduced to purge the air contained in the rotor gaps, and saturated vapor is introduced into the desorption zone 5-1 to desorb the carbon dioxide gas adsorbed on the rotor, which then passes through the first stage of the recovery zone 5-2 and is further recovered through the recovery zone 5-3 on the rotating front side.

[0084] For details regarding gas flow within the rotor, please refer to [link / reference]. Figure 5The rotor rotates from the treatment zone 4 to the purging zone 6, introducing unliquefied gas. Air contained in the rotor gaps is purged and discharged to the inlet side of the treatment zone 4, where it mixes with the treated air and is reintroduced into the treatment zone. This purging process serves several purposes: preventing air from mixing with the recovered gas, thereby increasing the recovery concentration; avoiding thermal oxidation and deterioration of the adsorbent material in the high-temperature desorption zone 5-1, thereby improving durability; and increasing the recovery rate by contacting and adsorbing carbon dioxide gas at a concentration higher than that of air before desorption. Simultaneously, by extracting unliquefied gas from the gas purification tank 16, the purity of the liquefied gas is also improved.

[0085] In desorption zone 5-1, saturated steam is introduced, and carbon dioxide gas is desorbed under the action of latent heat of condensation, while condensate remains inside the rotor. The mixture of desorbed carbon dioxide gas and water vapor passes through the first stage of recovery zone 5-2 in the direction of rotation, then turns back and passes through the second stage of recovery zone 5-3 for recovery. In this way, the enthalpy (sensible heat and latent heat) of the desorbed outlet gas is recovered into the residual heat of the rotor before desorption. Conversely, the enthalpy of the recovered gas is reduced, thereby reducing the load on the cooling and dehumidification coil 10-1 in the next process.

[0086] After testing confirms the effectiveness is sufficient, the number of stages in the recovery zone can be increased to three or four stages in the direction of rotation. Experiments to date have confirmed the effectiveness of a single stage and established the necessity of adding another stage and the potential for improved energy efficiency. Such complex flow path configurations and insulation treatments are difficult to achieve with conventional technologies, but can be achieved through a "layered purging and recovery block" structure (Patent Document 9). A layered structure composed of fan-shaped plates with or without their own regional spaces is described, wherein a block is formed by laminating and bonding a heat-resistant and wear-resistant sliding plate (the sliding surface in contact with the rotor end face), a foam rubber sheet layer below it, a foam rubber sheet layer or foam board layer with connecting channels between the sheets below it, and a heat-insulating board without regional spaces at the bottom. This "layered structure purging and recovery block" with a high-insulation structure having a steam inlet, a desorbed gas recovery section, and a purging gas inlet / outlet section on its outer periphery or bottom surface can be easily and cost-effectively manufactured.

[0087] [Third Embodiment of a Carbon Dioxide Gas Separation and Concentration Unit]

[0088] Figure 5 An example is shown where, while the desorption zone, the first recovery zone, the second recovery zone, and the gas passage direction are reversed simultaneously, gas is introduced into the rotor in a sequential manner towards the rotor's rotating front stage. However, if... Figure 6As shown, the desorption zone, the first recovery zone, and the second recovery zone all have the same gas flow direction. Gas bypasses each zone to the outer circumference of the rotor and flows helically towards the front stage along the direction of rotation. From the perspectives of processability, assembly adjustment, and thermal insulation, the bypass can be constructed by laminating and bonding multiple sheets of foamed silicone rubber tubing, with or without interrupted gas flow paths. This method is more thermodynamically preferable, but the structure is more complex, and the decision should be based on cost-effectiveness. If the air conditioning equipment is used in a confined, enclosed space (such as a spacecraft), performance can be considered more important than cost.

[0089] Now, let's estimate the recovery volume and scale of the wet TSA carbon dioxide separation and concentration unit when it is actually put into use, based on the results of the actual experiment (Patent Document 9). Figure 8 This is a flowchart of a small-scale experimental setup actually implemented, and is related to the present invention. Figure 4 Similar, but slightly different. For example, the purge gas is not an unliquefied gas. In the circulating purge zones 6-1 and 6-2, which are set before and after the recovery zone and the desorption zone, the gas contained in the rotor gap immediately after rotating to the desorption gas purge zone 6-1 is extracted from the desorption zone 5-1. Then, the processing air purge zone 6-2, which is located after the processing zone, purges the air contained in the rotor gap, thereby preventing air from mixing into the recovered gas.

[0090] The rotor is a honeycomb of amine adsorbent material with approximately 190 units. The experimental data during the optimization process shows that the concentration of recovered carbon dioxide gas is only about 50%, but the concentration can be further increased through adjustments. In addition, by purging the unliquefied gas of this invention, it is expected to achieve a high concentration recovery of nearly 100%.

[0091] Furthermore, the recovery rate of carbon dioxide gas from outside air (removal rate from the air-passing side) is not high, approximately 45%, but this is based on data from a rotor width of 50 mm and a processing airflow velocity of 3.3 m / s. Rotor width affects heat exchange efficiency in the case of a total heat exchanger, dehumidification capacity in the case of a dehumidifier, and removal rate in the case of a VOC concentration rotor. For high performance, a wider rotor, such as 200-600 mm, should be selected. Due to the laminar flow region, the increase in pressure loss is almost proportional to the rotor width and flow velocity, and varies with gas composition and temperature. For example, at an air velocity of 3.3 m / s and a temperature of 30°C, the pressure loss of a 190-unit rotor with a width of 400 mm is 550 Pa, while the pressure loss of a 50 mm wide rotor is approximately 140 Pa.

[0092] As the carbon dioxide separation and concentration device for the air of this invention, a width of 50 mm provides sufficient recovery. This is because, rather than pursuing a higher recovery rate, it is more efficient to utilize the advantages of a narrow rotor and low pressure loss, allowing a simple and inexpensive axial blower (such as a large ventilation fan) to draw in a large volume of processed air and adsorb a large amount of carbon dioxide gas with less power than a centrifugal blower. On the other hand, there are concerns that an excessively narrow width might reduce desorption efficiency. However, in this invention, by having the desorbed outlet gas recovered through one or more stages of recovery zones preceding the rotation direction, not only is sufficient desorption efficiency achieved, but energy savings are also improved through rotor preheating based on enthalpy recovery and the precooling and dehumidification of the desorbed gas.

[0093] The actual machine ratio is estimated based on experimental data. Figure 9 In a medium-sized box containing a separator and concentrator rotor with a diameter of approximately Φ2000mm and a width of 50mm, if the processing air volume is 40000m³... 3 If the carbon dioxide concentration is 400 ppm and the recovery rate is 45%, then the carbon dioxide gas recovery amount is 8 m³ / h. 3 / h≈14.2kg / h / unit. For example... Figure 10 As shown, if four such rotor boxes are combined into a square, only one large processing blower is needed to process approximately 2 pings (6.61157 m²). 2 It can separate and concentrate 56 kg / hour of carbon dioxide from the air within the installation area.

[0094] return Figure 3 System Description. The recovered gas is cooled and dehumidified by cooling coil 10-1, then enters the next stage compression unit 11-1 for pressurization and heating. The heated gas is then introduced into the rotary adsorption dehumidifier 12 (see detailed diagram). Figure 7 In the desorption zone 12-1, the moisture adsorbed on the rotor is desorbed, and the gas temperature is lowered and the absolute humidity is increased by the heat of desorption. Then, the gas is simultaneously cooled and dehumidified in the cooling and dehumidifying coil 10-2, and is introduced into the processing zone 12-2 for adsorption and dehumidification, and then introduced into the compression device 11-2 for further compression. By combining the cooling and dehumidifying coil 10-2 and the rotor dehumidifier 12, the dehumidification temperature can be reduced to a dew point temperature lower than the cooling water temperature, thus eliminating the need for Embodiment 1. Figure 1 The adsorption dehumidifier 13 shown can also save energy.

[0095] Since carbon dioxide gas is difficult to liquefy in the first-stage compressor, the gas exiting the processing zone 12-2 of the rotary dehumidifier 12 is introduced into the second-stage compressor 11-2 and pressurized to approximately 4 MPa. Although Figure 3Not shown, but if necessary, the gas will be further cooled and pressurized to approximately 6.4 MPa in a third-stage compression unit. The pressurized gas is then further cooled and liquefied in liquefaction unit 15.

[0096] At a pressure of 2.2 MPa, the liquefaction temperature needs to be cooled to below -15°C; at 3.9 MPa, it needs to be cooled to below 5°C; and at 6.4 MPa, it needs to be cooled to below 25°C. Higher compression is beneficial for liquefaction, but requires more energy from the compressor. Conversely, at lower pressures, liquefaction requires cooling to lower temperatures, but the dissolution of impurities decreases, and the purity of liquefied carbon dioxide increases. On the other hand, the load on the refrigeration unit increases, the coefficient of performance of the refrigeration unit deteriorates, and therefore energy demand increases. Patent document 7 discloses that, from the perspective of dry ice production, it is best to cool the dry ice to a supercooled state. Various factors should be considered during the design process.

[0097] Since the saturated steam used for desorption in the carbon dioxide gas separation and concentration unit is generated in the steam generation heat pump by recovering waste heat generated in systems such as the cooling unit and liquefaction refrigeration unit, the increase in the compression load and cooling load for dry ice production leads to an increase in the waste heat source for saturated steam generation. This makes the entire system mutually reinforcing and improves energy efficiency. If the waste heat source is insufficient, there is waste heat from cooling during the dry ice demand period, and solar energy is also abundant, so it can be supplemented.

[0098] The treated outlet gas, due to its low carbon dioxide concentration, can be used as air conditioning supply. By cooling and dehumidifying the air in the treatment zone after passing through the carbon dioxide gas separation and concentration rotor with cooling coils before supplying it to the air conditioner, and recovering the water discharged from the cooling coils and sending it to a saturated steam generator, energy saving in air conditioning, increased added value of the system, and water conservation can be achieved. The advantage of this method is that it can be used for air conditioning in enclosed spaces such as space facilities.

[0099] The liquefied gas is placed in a purification tank, but it contains unliquefied gas. This unliquefied gas is usually discharged to improve the purity of the liquefied gas. The unliquefied gas contains impurities, but its main component is carbon dioxide. By introducing this unliquefied gas into the purge zone of the rotor-type separator and concentrator, various problems caused by the transfer of air contained in the rotor gaps to the desorption zone due to rotor rotation can be eliminated. First, air purging increases the concentration of recovered carbon dioxide. Second, high-concentration carbon dioxide gas passing through the recovery zone further increases gas adsorption on the rotor, increasing the amount of carbon dioxide recovered. Third, by not introducing oxygen-containing gas into the desorption zone, it also prevents the thermal oxidation and deterioration of amine-based carbon dioxide adsorbent materials in the desorption zone.

[0100] Liquefied carbon dioxide products require dehumidification to ensure that the moisture content meets specifications. However, carbon dioxide gas used in dry ice applications does not require the same high level of dehumidification as liquefied gases because the production of block dry ice contains water and other solidifying agents to solidify into snow-like dry ice.

[0101] Although this invention is designed as a dry ice production system with consideration for the widespread availability of CCU technology, it is possible to further purify liquefied carbon dioxide into liquefied carbon dioxide products without using dry ice. Furthermore, while the density of liquefied carbon dioxide is approximately 0.77 g / m³, the specific gravity of dry ice is approximately 1.56 g / m³, twice that of carbon dioxide. This means that the volume of dry ice is only half that of liquefied carbon dioxide, and it eliminates the need for heavy high-pressure cylinders. Therefore, it can also be assumed that this invention can be developed for CCUS plants as a method for transporting and collecting dry ice in highly insulated containers with low carbon emissions.

[0102] Industrial availability

[0103] This invention relates to a dry ice production system using carbon dioxide from the air as a gas source, capable of providing air conditioning ventilation. This system is not limited to traditional carbon dioxide emission sources and waste heat sources, and can produce the required quantity of dry ice in the required area when needed, thus eliminating the need for reserves to account for seasonal fluctuations. Furthermore, the system is highly energy-efficient by utilizing the waste heat and exhaust gases generated during separation, concentration, compression, cooling, dehumidification, and liquefaction processes. Moreover, the system is a complete system from carbon dioxide gas separation and concentration to product production, thus providing a dry ice production system using carbon dioxide from the air that can be installed in small-scale dry ice demand areas without increasing carbon dioxide emissions due to transportation, and capable of providing air conditioning ventilation.

[0104] Explanation of reference numerals in the attached figures:

[0105] 1. Carbon dioxide adsorption rotor

[0106] 2-rotor drive motor

[0107] 3 rotor drive belt

[0108] 4 processing areas

[0109] 5-1 Desorption Zone

[0110] 5-2 Recycling Area 1

[0111] 5-3 Recycling Area 2

[0112] 6 Blowing Zone

[0113] 6-1 Desorption Gas Purge Zone

[0114] 6-2 Processing Air Purging Area

[0115] 7. Air handling blower

[0116] 8 Steam generators

[0117] 9 cooling towers

[0118] 10-1 Gas Cooling Coil 1

[0119] 10-2 Gas Cooling Coil 2

[0120] 10-3 Gas Cooling Coil 3

[0121] 11-1 Gas Compressor 1

[0122] 11-2 Gas Compressor 2

[0123] 12-cell honeycomb rotor rotary adsorption dehumidifier

[0124] 12-1 Regeneration Zone.

[0125] 12-2 Processing Area

[0126] 13 Adsorption-type dual-tower dehumidifier

[0127] 14 Refrigeration units

[0128] 15 Carbon dioxide gas liquefaction unit

[0129] 16 Liquefied Carbon Dioxide Purification Tank

[0130] 17 Dry Ice Production Unit

[0131] 18 circulating purge pump

Claims

1. A dry ice production system using carbon dioxide from the air as a gas source, wherein, The dry ice production system includes: a steam-generating heat pump unit that recovers waste heat from devices used for compressing, cooling, and liquefying carbon dioxide gas to generate steam; a carbon dioxide gas separation and concentration unit that separates and concentrates carbon dioxide gas from air, introduces the steam, and recovers it through desorption using the condensation heat of the saturated steam; a device for cooling and dehumidifying a mixture of saturated steam and carbon dioxide gas recovered by the separation and concentration unit; a compression unit of at least one stage that compresses the cooled and dehumidified carbon dioxide gas to liquefy it; an adsorption dehumidification unit for dehumidifying the compressed carbon dioxide gas; a gas liquefaction unit and a refrigeration unit for cooling the dehumidified carbon dioxide gas to its liquefaction temperature; a liquefied carbon dioxide purification tank that introduces and stores the liquefied carbon dioxide gas and extracts unliquefied gas; and a system for discharging the liquefied carbon dioxide from the liquefied carbon dioxide purification tank. A dry ice production apparatus that releases carbon dioxide gas under atmospheric pressure and utilizes its latent heat of vaporization to cool and sublimate the gas to generate dry ice; in a dry ice production system that returns the unsublimated gas generated during dry ice production to a compression unit for recovery, the carbon dioxide gas separation and concentration device is a wet TSA carbon dioxide separation and concentration device, which houses and rotates rotors with carbon dioxide gas adsorption capacity in at least the order of rotation into sealed housings having a processing zone, a purging zone, and a desorption zone. In the processing zone, carbon dioxide gas is adsorbed while the rotor is in a wet state, air is introduced to vaporize and cool it. In the purging zone, unliquefied gas extracted from the liquefied carbon dioxide purification tank is introduced to purge and discharge the air contained in the rotor gaps. In the desorption zone, saturated steam at approximately 100°C generated by a steam generating heat pump is introduced, and the heat of condensation of the steam is used to desorb carbon dioxide gas and concentrate and recover it.

2. The dry ice production system using carbon dioxide from the air as a gas source according to claim 1, wherein, The wet TSA carbon dioxide gas separation and concentration device houses and rotates a rotor with carbon dioxide adsorption capacity into a sealed housing containing a treatment zone, a purge zone, multiple recovery zones (at least one stage), and a desorption zone in sequence according to the direction of rotation. In the treatment zone, air is introduced while the rotor is wet to vaporize and cool it. In the purge zone, unliquefied gas from a liquefied carbon dioxide purification tank is introduced to expel air contained in the rotor gaps. In the desorption zone, saturated steam at approximately 100°C is introduced, and the high concentration of carbon dioxide gas is desorbed using the condensation heat of the steam. In the recovery zone, the desorbed gas is sequentially passed through multiple recovery zones (at least one stage) towards the front of the rotation direction for recovery.

3. The dry ice production system using carbon dioxide from the air as a gas source according to claim 1, wherein, The air from the processing area of ​​the wet TSA carbon dioxide gas separation and concentration unit is cooled and dehumidified by cooling coils and used as air conditioning supply air, and the drainage from the cooling coils is recycled and used as water supply for the saturated steam generator.

4. The dry ice production system using carbon dioxide from the air as a gas source according to claim 1, wherein, The adsorption dehumidification device introduces compressed high-temperature gas from a gas compression device into the regeneration zone of a honeycomb rotor dehumidifier, which has a treatment zone and a regeneration zone, to desorb the adsorbed water on the rotor. The outlet gas is then cooled and dehumidified by passing through a cooling coil before being introduced into the treatment zone for adsorption dehumidification.

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