Carbon dioxide purification system based on multistage cryogenic coupling

Abstract

The invention discloses a carbon dioxide purification system based on multi-stage cryogenic coupling, and relates to the technical field of carbon dioxide purification, the carbon dioxide purification system comprises a pretreatment module, a multi-stage compression cooling module, a cryogenic coupling separation module, an adsorption separation module and an intelligent regulation and control module which are sequentially connected through pipelines; through the synergistic effect of the three-stage centrifugal compressor and vortex tube refrigeration, the carbon dioxide liquefaction efficiency is remarkably improved, meanwhile, the system utilizes the pressure balance valve to dynamically couple gradient temperature control of the cryogenic adsorption tower and the membrane separation assembly, the gas-liquid entrainment problem in the phase change process is effectively solved, and the carbon dioxide liquefaction efficiency is improved. Through cooperation of high-temperature cascade refrigeration and low-temperature vortex refrigeration, gradient temperature control layered adsorption of a cryogenic adsorption tower and dynamic separation of a membrane separation assembly are integrated, the recovery efficiency can be greatly improved, in addition, the system is provided with a multi-physics field sensor array, and operation parameters are dynamically regulated and controlled in combination with an intelligent optimization algorithm of a distributed edge calculation unit, so that the recovery efficiency is improved. And the energy efficiency ratio and the operation stability of the system can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide purification, and in particular to a carbon dioxide purification system based on multi-stage cryogenic coupling. Background Art

[0002] Carbon dioxide (chemical formula: CO2) is a compound composed of one carbon atom and two oxygen atoms. It is one of the important components of the Earth's atmosphere. It is a colorless and odorless gas at room temperature and pressure. Its density is greater than that of air. It can be dissolved in water to form carbonic acid. It is non-flammable and does not support combustion, but it can react with strong reducing agents (such as magnesium) to produce carbon. In industry, it can be used as welding shielding gas and supercritical fluid extraction. Food-grade CO2 can be used for beverage carbonation. In agriculture, it can be used as a greenhouse gas for fertilization. In energy, it can be used in geothermal systems and carbon dioxide flooding.

[0003] Carbon dioxide purification refers to the process of separating, concentrating and increasing the purity of carbon dioxide from mixed gases through physical or chemical methods. The existing carbon dioxide purification technologies mainly include chemical absorption, physical adsorption, membrane separation, cryogenic distillation and biological fixation. Carbon dioxide purification is a key link in the carbon neutrality strategy, and its technological progress directly affects the carbon trading cost.

[0004] Multi-stage deep-cold coupling technology couples the high-temperature and low-temperature refrigeration cycles with each other, using the high-temperature evaporator as the low-temperature condenser to achieve heat transfer and efficient energy utilization. This method can break through the temperature limit of the single-stage refrigeration system, achieve lower refrigeration temperatures, and meet the needs of the ultra-low temperature field.

[0005] Traditional carbon dioxide purification technology is limited by refrigeration limits, making it difficult to liquefy carbon dioxide efficiently. The liquefaction efficiency is insufficient, and conventional adsorption or membrane separation methods sacrifice recovery rate when improving purity, resulting in a contradiction between purity and recovery rate. In addition, gas-liquid entrainment in traditional cryogenic processes causes purity fluctuations, which can lead to unstable phase change processes. At the same time, existing carbon dioxide purification technology relies more on fixed operating parameters, and the system operation flexibility needs to be improved. Therefore, the present invention proposes a carbon dioxide purification system based on multi-stage cryogenic coupling to solve the problems existing in the prior art. Summary of the Invention

[0006] In response to the above problems, the purpose of the present invention is to propose a carbon dioxide purification system based on multi-stage cryogenic coupling to solve the problems of insufficient liquefaction efficiency, contradiction between purity and recovery rate, unstable phase change process and low system operation flexibility existing in traditional carbon dioxide purification technology.

[0007] In order to achieve the purpose of the present invention, the present invention is implemented through the following technical solutions: a carbon dioxide purification system based on multi-stage cryogenic coupling, comprising a pretreatment module, a multi-stage compression and cooling module, a cryogenic coupling separation module, an adsorption separation module and an intelligent control module connected in sequence by pipelines, the pretreatment module is connected to the supply port of the carbon dioxide raw gas to be purified through a pipeline, the multi-stage compression and cooling module comprises a cyclone dust collector for filtering dust, an ozone oxidation reactor for removing organic impurities and a temperature-swing adsorption tower for adsorbing moisture, the pretreatment module comprises a three-stage centrifugal compressor for heating and pressurizing the carbon dioxide raw gas and a plate-fin heat exchanger for heat exchange of the heated and pressurized carbon dioxide raw gas, the cryogenic coupling separation module integrates a high-temperature cascade refrigerator for condensing carbon dioxide gas and a low-temperature vortex tube refrigerator for further cooling the carbon dioxide gas, the adsorption separation module comprises a cryogenic adsorption tower and a membrane separation component dynamically coupled by a pressure balancing valve, the intelligent control module is configured with a multi-physical field sensor array and a distributed edge computing unit and dynamically adjusts the operating parameters of each module.

[0008] Further improvements are: the cyclone dust collector realizes gas-solid separation of carbon dioxide raw gas by centrifugal force, and the ozone oxidation reactor includes a honeycomb TiO2 catalyst carrier layer for oxidizing and removing organic impurities and an ultraviolet excitation module for activating the catalyst.

[0009] A further improvement is that the temperature swing adsorption tower includes an upper molecular sieve layer for adsorbing moisture and a lower activated carbon-loaded CuO catalyst layer for catalytically oxidizing H2S to elemental sulfur.

[0010] A further improvement is that the three-stage centrifugal compressor consists of a first-stage impeller, a second-stage impeller and a third-stage impeller, and the plate-fin heat exchanger is connected in series with the three-stage centrifugal compressor and realizes efficient heat exchange between cold and hot fluids through several layers of alternating metal plates and fins.

[0011] Further improvements are as follows: the high-temperature cascade refrigerator consists of a spirally wound heat exchanger for achieving heat exchange, a magnetically levitation centrifugal compressor for eliminating mechanical friction and an expander for achieving refrigeration; a gas-liquid cyclone separator for separating the gas-liquid mixture, a microchannel condenser for achieving condensation and a dynamic expansion valve for controlling pressure are provided between the cold end outlet of the low-temperature vortex tube refrigerator and the deep-cold adsorption tower.

[0012] Further improvements are: the deep-cold adsorption tower includes a gradient temperature control jacket for controlling the temperature inside the tower, a layered filling adsorbent for improving the adsorption rate and a microwave regeneration module for achieving adsorbent regeneration; the membrane separation component consists of a support layer for providing structural support, a selective layer for achieving gas selective separation and a protective layer for enhancing the mechanical properties of the membrane.

[0013] Further improvements are: the multi-physics field sensor array is evenly arranged on the connecting pipes between the modules of the system, the propagation time and attenuation of the sound wave in the mixed gas are measured by the acoustic sensor, the sound speed and sound attenuation distribution are calculated, and the temperature field, velocity field and concentration field are reconstructed. The distributed edge computing unit analyzes the temperature field, concentration field and pressure field data in real time, and dynamically adjusts the operating parameters of each module of the system through the chaos optimization algorithm.

[0014] A further improvement is that it also includes a waste cooling recovery device, which is connected between the cryogenic adsorption tower and the supply port of the carbon dioxide raw gas to be purified through a pipeline, and exchanges heat between the low-temperature exhaust gas discharged from the cryogenic adsorption tower and the carbon dioxide raw gas in the supply port of the carbon dioxide raw gas to be purified.

[0015] The beneficial effects of the present invention are as follows: the present invention breaks through the limits of traditional refrigeration through the synergistic effect of the three-stage centrifugal compressor and the vortex tube refrigeration, achieves deep cooling, and significantly improves the carbon dioxide liquefaction efficiency. At the same time, the system uses the pressure balance valve to dynamically couple the gradient temperature control of the deep-cold adsorption tower and the membrane separation component, effectively solving the problem of gas-liquid entrainment in the phase change process, and combining highly selective adsorption materials and composite membrane separation technology to ensure that the carbon dioxide purity reaches ultra-high standards. Moreover, through the synergy of high-temperature cascade refrigeration and low-temperature vortex refrigeration, the gradient temperature control layered adsorption of the deep-cold adsorption tower and the dynamic separation of the membrane separation component are integrated to form a multi-dimensional purification system, which greatly improves the recovery efficiency. In addition, the system is equipped with a multi-physical field sensor array to monitor the temperature, concentration and flow rate distribution in real time, and combined with the intelligent optimization algorithm of the distributed edge computing unit to dynamically control the operating parameters, which can significantly improve the energy efficiency ratio and operating stability, and realize the efficient purification and green production of carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the connection structure of each module of the carbon dioxide purification system based on multi-stage cryogenic coupling of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] Carbon dioxide is a carbon oxide with the chemical formula C02. At room temperature and pressure, it is a colorless and odorless or colorless and odorless gas with a slightly sour taste when dissolved in water. It is also a common greenhouse gas and a component of air. It is a gas with a strong pungent odor. If people inhale too much carbon dioxide, there is a risk of suffocation or even death.

[0019] At the same time, carbon dioxide is also a widely used industrial raw material. It is mainly used as a raw material for the manufacture of soda ash, fertilizers, and the synthesis of methanol and inorganic salts. It is also used for quenching steel castings and for the manufacture of dry ice. Liquid carbon dioxide is used in welding, fermentation industry, cooling, food and beverages, sugar making, and medical local anesthesia. It can also be used as an anti-foaming agent for large steel castings, a plant growth promoter, an antioxidant, and a fire extinguishing agent.

[0020] In recent years, with the development of the economy and the increase in sustainable development efforts, the demand for CO2 has also increased. Therefore, the number of companies recycling CO2 has increased, and the CO2 production capacity and demand have also increased year by year. Faced with the demand for carbon dioxide for different uses, purifying carbon dioxide has also become an inevitable trend.

[0021] according to Figure 1 As shown, this embodiment provides a carbon dioxide purification system based on multi-stage cryogenic coupling, which consists of a pretreatment module, a multi-stage compression cooling module, a cryogenic coupling separation module, an adsorption separation module and an intelligent control module, wherein:

[0022] The pretreatment module is connected to the supply port of the carbon dioxide raw gas to be purified through a pipeline. It receives the carbon dioxide raw gas to be purified and performs corresponding pretreatment for the system to remove H2S, moisture and hydrocarbon impurities. It includes a cyclone dust collector, an ozone oxidation reactor and a temperature swing adsorption tower connected in sequence. The cyclone dust collector uses centrifugal force to remove large particles of dust in the carbon dioxide raw gas to improve gas purity. The ozone oxidation reactor is used to remove organic impurities, and the temperature swing adsorption tower is used to absorb moisture.

[0023] The multi-stage compression cooling module is connected to the pretreatment module through a pipeline, receives the pretreated gas and performs multi-stage compression processing. It consists of a three-stage centrifugal compressor and a plate-fin heat exchanger in series. The outlet gas temperature is ≤-45°C. The three-stage centrifugal compressor heats and pressurizes the pretreated carbon dioxide feed gas, increases the gas pressure to enhance the subsequent liquefaction efficiency, and provides sufficient thermodynamic driving force for the plate-fin heat exchanger. The plate-fin heat exchanger performs heat exchange on the heated and pressurized carbon dioxide feed gas. The high-temperature and high-pressure gas enters the plate-fin heat exchanger and performs countercurrent heat exchange with the low-temperature cold source (refrigerant). The gas temperature is greatly reduced, and part of the CO2 begins to liquefy. At the same time, the cooling capacity is recovered to reduce the total energy consumption of the system.

[0024] The cryogenic coupling separation module is connected to the multi-stage compression cooling module through pipelines and integrates a high-temperature cascade refrigerator and a low-temperature vortex tube refrigerator. The high-temperature cascade refrigerator provides sufficient cooling capacity through the refrigeration cycle to condense the high-pressure carbon dioxide gas into liquid, ensuring that the carbon dioxide enters the adsorption separation module in liquid form, improving purification efficiency. The low-temperature vortex tube refrigerator further reduces the temperature of the incompletely condensed carbon dioxide gas through physical methods, reducing dependence on traditional refrigerants and minimizing environmental impact.

[0025] The adsorption separation module is connected to the cryogenic coupling separation module through a pipeline, and includes a cryogenic adsorption tower and a membrane separation component. The cryogenic adsorption tower and the membrane separation component are dynamically coupled by a pressure balance valve. The cryogenic adsorption tower is filled with MOFs material, the adsorption temperature is -60 to -80 ° C, the pressure is 2 to 5 MPa, and the membrane separation component is a hollow fiber membrane group.

[0026] The intelligent control module is electrically connected to each module of the system and dynamically adjusts the operating parameters of each module. It is equipped with a multi-physics field sensor array and a distributed edge computing unit. The multi-physics field sensor array can obtain the temperature, velocity and concentration information of the gas during the carbon dioxide purification process in real time, detect abnormal situations in time, and ensure the safety and stability of the purification process. The distributed edge computing unit analyzes the temperature field, concentration field and pressure field data obtained from the multi-physics field sensor array in real time, and dynamically adjusts the operating parameters of each module of the system through a chaotic optimization algorithm.

[0027] In this embodiment, the cyclone dust collector uses centrifugal force to cause the dust-laden carbon dioxide feed gas to rotate at high speed inside the device, generating centrifugal force that flings heavier particles toward the wall. The particles then fall into the hopper under the action of gravity, thereby achieving gas-solid separation. The structure is simple, maintenance is convenient, and the capture efficiency of particles with a diameter greater than 5 μm is high.

[0028] The ozone oxidation reactor includes a honeycomb TiO2 catalyst carrier and a UV excitation module. The specific surface area of ​​the honeycomb TiO2 catalyst carrier is ≥200m 2 / g, the ozone dosage is 0.5~1.2g / Nm 3 By utilizing the photocatalytic properties of TiO2, under ultraviolet light irradiation, it can effectively oxidize and remove organic impurities in the raw gas. The ultraviolet excitation module activates the honeycomb TiO2 catalyst carrier layer by emitting ultraviolet light of a specific wavelength, enhancing its photocatalytic performance, and jointly ensuring the purity of the carbon dioxide raw gas, creating good conditions for the subsequent purification process.

[0029] In this embodiment, the temperature swing adsorption tower includes an upper molecular sieve layer and a lower activated carbon-loaded CuO catalyst layer. The upper molecular sieve layer is used to adsorb moisture (dew point ≤ -70°C), and the lower activated carbon-loaded CuO catalyst layer catalytically oxidizes H2S to elemental sulfur at 80-120°C.

[0030] In this embodiment, the three-stage centrifugal compressor includes a first-stage impeller, a second-stage impeller, and a third-stage impeller. The gas enters the first-stage impeller, the second-stage impeller, and the third-stage impeller in sequence, gradually increasing the pressure and temperature of the carbon dioxide in the feed gas. The process is as follows:

[0031] First stage compression: Gas enters the first stage impeller, and the pressure and temperature begin to rise;

[0032] Secondary compression: The gas compressed in the first stage enters the second stage impeller, where the pressure and temperature are further increased;

[0033] Three-stage compression: The gas after the second-stage compression enters the third-stage impeller and eventually reaches the required high-pressure state;

[0034] The plate-fin heat exchanger is connected in series with the three-stage centrifugal compressor and uses several layers of alternating metal plates and fins to increase the heat exchange area and achieve efficient heat exchange between cold and hot fluids.

[0035] In this embodiment, the high temperature cascade refrigerator includes a spiral wound heat exchanger (heat exchange area density 800m 2 / m 3 ), magnetic levitation centrifugal compressor (isentropic efficiency ≥ 92%) and expander (using 3D printed titanium alloy impeller, adiabatic efficiency ≥ 88%). The spirally wound heat exchanger achieves efficient heat exchange through a spiral winding structure. The magnetic levitation centrifugal compressor uses magnetic levitation bearing technology to eliminate mechanical friction, improve operating efficiency, and reduce energy consumption. The expander performs external work and consumes internal energy by adiabatically expanding the high-pressure refrigerant gas, resulting in a significant reduction in gas temperature and achieving a cooling effect.

[0036] Between the cold end outlet of the low temperature vortex tube refrigerator and the deep cold adsorption tower, there are gas-liquid cyclone separator (separation efficiency ≥ 99.9%), microchannel condenser (heat transfer coefficient ≥ 5000W / (m 2 K) and a dynamic expansion valve (opening adjustment accuracy ±0.5%). The gas-liquid cyclone separator uses the principle of centrifugal force to fling droplets in the gas-liquid mixture toward the wall to achieve gas-liquid separation. The microchannel condenser achieves rapid heat exchange and improves condensation efficiency by increasing the contact area between the refrigerant and the tube wall. The dynamic expansion valve can accurately control the refrigerant flow and pressure to ensure stable operation of the system.

[0037] In this embodiment, the cryogenic adsorption tower includes a gradient temperature control jacket, layered filling adsorbents and a microwave regeneration module (frequency 2.45 GHz, power density 0.5-3 W / g), wherein the gradient temperature control jacket is formed by setting a jacket on the outer wall of the adsorption tower and passing a heat medium or cooling medium of different temperatures to form a temperature gradient from bottom to top, forming a temperature field of -80°C (bottom) to -30°C (top), and the layered filling adsorbents are different types of adsorbents filled in the adsorption tower in a specific order, and each layer of adsorbent is for different impurities or gas components. The microwave regeneration module uses a microwave generator and a waveguide to send microwaves to the adsorbent to heat and regenerate it;

[0038] The membrane separation component is a hollow fiber membrane group. At -20°C and a pressure difference of 1.5MPa, the CO2 permeation rate is ≥1200GPU and the CO2 / N2 selectivity is ≥180. The hollow fiber membrane group is composed of a support layer, a selection layer and a protective layer. The support layer is a polysulfone hollow fiber with a pore size of 50nm and a porosity of 75%, which provides mechanical strength and structural support to prevent membrane deformation or rupture. The selection layer adopts a polyethylene amine / graphene quantum dot composite coating with a thickness of 80 to 120nm, has gas selective permeability, and realizes the selective separation of specific gases such as carbon dioxide. The protective layer is polydimethylsiloxane with a thickness of 5 to 8μm, which covers the surface of the selection layer to enhance the mechanical properties of the membrane and prevent damage without affecting the gas permeability.

[0039] In this embodiment, a multi-physics sensor array is evenly arranged on the connecting pipes between the modules of the system. Acoustic sensors are used to measure the propagation time and attenuation of sound waves in the mixed gas, calculate the sound velocity and sound attenuation distribution, and reconstruct the temperature field, velocity field, and concentration field. The details are as follows:

[0040] Sound wave propagation time measurement: By measuring the time it takes for a sound wave to propagate in a gas, the speed of sound can be calculated. The speed of sound is closely related to the temperature and composition of the gas, and thus can reflect the temperature and concentration information of the gas.

[0041] Acoustic wave attenuation measurement: When sound waves propagate in gas, they attenuate. The degree of attenuation is affected by the gas composition and temperature. By measuring the attenuation of sound waves, the concentration and temperature distribution of the gas can be obtained.

[0042] Data processing and reconstruction: The collected sound velocity and attenuation data are processed and the temperature, velocity, and concentration fields within the measured area are reconstructed using an inversion algorithm. This provides an important basis for real-time monitoring and control of the carbon dioxide purification process.

[0043] By using acoustic sensors, there is no need for direct contact with the gas, which reduces interference with the system and the need for maintenance. By placing a multi-physics sensor array in areas with the most significant vibration amplitude or the most prominent vibration characteristics (connecting pipes between modules), key parameters of the carbon dioxide purification system can be effectively monitored, optimizing system performance and reducing operating costs.

[0044] The distributed edge computing unit dynamically adjusts the operating parameters of each system module, specifically including the following steps:

[0045] Data analysis: Distributed edge computing units analyze data acquired by the multi-physics sensor array and extract characteristic information reflecting the system's operating status, such as temperature distribution, concentration changes, and pressure fluctuations.

[0046] Multi-source data fusion: Utilizes spatiotemporal alignment algorithms to resolve data heterogeneity issues, achieve fusion of multi-source data, and obtain comprehensive system status information;

[0047] Initialization parameters: Initialize the parameters of the chaos optimization algorithm, such as population size, number of iterations, etc., based on the current state of the system and historical data;

[0048] Chaotic mapping and dynamic adjustment: Chaotic mapping is used to generate random sequences, initialize the population, avoid falling into local optimality, dynamically adjust control parameters, and enhance the algorithm's global search capability and convergence speed;

[0049] Parameter optimization: Through the chaos optimization algorithm, the operating parameters of each module of the system are optimized to find the best parameter combination to improve the operating efficiency and stability of the system;

[0050] Parameter distribution: The optimized operating parameters are distributed to the control units of each module to dynamically adjust system operating parameters, such as cooling power, adsorption cycle, pressure balance valve opening, etc.

[0051] Real-time feedback and iterative optimization: During system operation, the operating results are continuously monitored, and parameters are fine-tuned based on feedback results to achieve iterative optimization and ensure that the system is always in the optimal operating state.

[0052] In this embodiment, a waste cooling recovery device is connected between the cryogenic adsorption tower and the supply port of the carbon dioxide raw gas to be purified through a pipeline. The waste cooling recovery device exchanges heat between the low-temperature exhaust gas discharged from the cryogenic adsorption tower and the carbon dioxide raw gas in the supply port of the carbon dioxide raw gas to be purified, thereby reducing the total energy consumption of the system.

[0053] When the carbon dioxide purification system based on multi-stage cryogenic coupling is actually used, the carbon dioxide raw gas in the carbon dioxide raw gas supply port is introduced into the pretreatment module for pretreatment, and the carbon dioxide raw gas containing CO2 (20-50%) is removed of impurities to H2S <1ppm and water dew point ≤-70°C through the pretreatment module; the pretreated gas is introduced into the multi-stage compression cooling module, and the multi-stage compression cooling module is used to compress the gas to 4.5MPa and cool it to -55°C; the cooled gas is introduced into the cryogenic coupling separation module, and the cryogenic coupling separation module produces a -95°C refrigerant, so that more than 90% of the CO2 in the gas is condensed and liquefied and separated; the uncondensed gas is introduced into the adsorption separation module, and the cryogenic adsorption tower in the adsorption separation module is used to selectively adsorb CO2. After adsorption saturation, the temperature is raised to 40°C for desorption to obtain CO2 gas with a purity of ≥99.5%. The desorbed gas is purified for a second time through the membrane separation component, realizing the entire carbon dioxide purification work based on multi-stage cryogenic coupling, and the final CO2 purity is ≥99.99% and the recovery rate is ≥95%.

[0054] The system of the present invention is applied to refinery tail gas treatment, and the measured data are as follows:

[0055] Processing capacity 2000Nm 3 / h, inlet CO2 concentration of 32%, outlet CO2 purity of 99.9993%, methane residue <0.5ppm, the system continuously operates for 8000h without frosting failure, GWP value <100 (traditional Freon solution >2000), and meets the electronic grade CO2 standard (SEMI C12-0708).

[0056] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A carbon dioxide purification system based on multi-stage cryogenic coupling, comprising a pretreatment module, a multi-stage compression cooling module, a cryogenic coupling separation module, an adsorption separation module, and an intelligent control module, which are sequentially connected by pipelines, characterized in that: The pretreatment module is connected to the supply port of the carbon dioxide raw gas to be purified through a pipeline. The pretreatment module includes a cyclone dust collector for filtering dust, an ozone oxidation reactor for removing organic impurities and a temperature-variable adsorption tower for adsorbing moisture. The multi-stage compression and cooling module includes a three-stage centrifugal compressor for heating and pressurizing the carbon dioxide raw gas and a plate-fin heat exchanger for heat exchange of the heated and pressurized carbon dioxide raw gas. The deep-cold coupling separation module integrates a high-temperature cascade refrigerator for condensing carbon dioxide gas and a low-temperature vortex tube refrigerator for further cooling the carbon dioxide gas. The adsorption separation module includes a deep-cold adsorption tower and a membrane separation component dynamically coupled by a pressure balancing valve. The intelligent control module is configured with a multi-physical field sensor array and a distributed edge computing unit and dynamically adjusts the operating parameters of each module.

2. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The cyclone dust collector achieves gas-solid separation of the carbon dioxide raw gas through centrifugal force, and the ozone oxidation reactor includes a honeycomb TiO2 catalyst carrier layer for oxidizing and removing organic impurities and an ultraviolet excitation module for activating the catalyst.

3. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The temperature swing adsorption tower comprises an upper molecular sieve layer for adsorbing moisture and a lower activated carbon-loaded CuO catalyst layer for catalytically oxidizing H2S to elemental sulfur.

4. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The three-stage centrifugal compressor consists of a first-stage impeller, a second-stage impeller and a third-stage impeller. The plate-fin heat exchanger is connected in series with the three-stage centrifugal compressor and realizes efficient heat exchange between cold and hot fluids through several layers of alternately arranged metal plates and fins.

5. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The high-temperature cascade refrigerator consists of a spirally wound heat exchanger for achieving heat exchange, a magnetically levitated centrifugal compressor for eliminating mechanical friction, and an expander for achieving refrigeration. A gas-liquid cyclone separator for separating the gas-liquid mixture, a microchannel condenser for achieving condensation, and a dynamic expansion valve for controlling pressure are provided between the cold end outlet of the low-temperature vortex tube refrigerator and the deep-cold adsorption tower.

6. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The cryogenic adsorption tower includes a gradient temperature control jacket for controlling the temperature inside the tower, a layered adsorbent for improving the adsorption rate, and a microwave regeneration module for regenerating the adsorbent. The membrane separation component consists of a support layer for providing structural support, a selection layer for achieving selective gas separation, and a protective layer for enhancing the mechanical properties of the membrane.

7. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: The multi-physics field sensor array is evenly arranged on the connecting pipes between the modules of the system. The propagation time and attenuation of the sound wave in the mixed gas are measured by the acoustic sensor, the sound speed and sound attenuation distribution are calculated, and the temperature field, velocity field and concentration field are reconstructed. The distributed edge computing unit analyzes the temperature field, concentration field and pressure field data in real time, and dynamically adjusts the operating parameters of each module of the system through the chaos optimization algorithm.

8. The carbon dioxide purification system based on multi-stage cryogenic coupling according to claim 1, characterized in that: It also includes a waste cooling recovery device, which is connected between the cryogenic adsorption tower and the supply port of the carbon dioxide raw gas to be purified through a pipeline, and exchanges heat between the low-temperature tail gas discharged from the cryogenic adsorption tower and the carbon dioxide raw gas in the supply port of the carbon dioxide raw gas to be purified.

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