A method and system for carbon dioxide purification based on temperature swing adsorption

Abstract

This invention relates to the field of energy-saving and environmentally friendly carbon dioxide purification technology, specifically a carbon dioxide purification method and system based on temperature-switching adsorption. The method includes: removing condensate impurities from pre-acquired industrial-grade carbon dioxide feed gas to obtain pre-treated carbon dioxide feed gas; desulfurizing the pre-treated carbon dioxide feed gas to obtain desulfurized carbon dioxide process gas; subjecting the desulfurized carbon dioxide process gas to temperature-switching adsorption to obtain low-impurity carbon dioxide process gas; distilling the low-impurity carbon dioxide process gas to remove heavy components to obtain refined carbon dioxide gas; and cooling and liquefying the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide. This invention can improve the precision of carbon dioxide purification in industrial production.

Description

Technical Field

[0001] This invention relates to the field of environmentally friendly and energy-saving gas purification technology, and in particular to a carbon dioxide purification method and system based on temperature-switching adsorption. Background Technology

[0002] Carbon dioxide purification is used to remove impurities from industrial-grade carbon dioxide feedstock through multiple stages to prepare electronic-grade liquid carbon dioxide that meets the requirements of high-end electronics applications. Taking semiconductor manufacturing as an example, by implementing carbon dioxide purification processes on industrial-grade carbon dioxide feedstock, high-purity, low-impurity electronic-grade liquid carbon dioxide can be obtained, thus meeting the stringent raw material requirements in semiconductor device manufacturing processes.

[0003] Existing technologies, such as the patent "Carbon Dioxide Purification System and Method in Flue Gas", application number: CN201210142125.9, include the following steps: compressing flue gas to form high-pressure flue gas; exchanging heat between the high-pressure flue gas and low-temperature air to form high-pressure low-temperature flue gas, so that some carbon dioxide in the high-pressure low-temperature flue gas is liquefied, wherein the pressure of the high-pressure low-temperature flue gas is 1.5MPa~2.5MPa and the temperature is -25℃~-35℃; before compression, the flue gas is first desulfurized to remove sulfur dioxide from the flue gas, and the flue gas is subjected to low-temperature plasma-induced oxidation to oxidize the sulfur dioxide in the flue gas into sulfur trioxide; the flue gas that has undergone low-temperature plasma-induced oxidation is reacted with an alkaline solution to react the sulfur trioxide in the flue gas with the alkaline solution to generate a solution containing SO4; and the liquefied carbon dioxide in the high-pressure low-temperature flue gas and the tail gas after removing the liquefied carbon dioxide are separated.

[0004] However, this method is simple in process and has low filtration efficiency for various impurities, which cannot meet the requirements of electronic-grade liquid carbon dioxide.

[0005] Currently, carbon dioxide purification methods typically involve workers setting fixed process parameters based on industry experience and manually processing industrial-grade carbon dioxide feedstock in stages. However, this method relies heavily on the experience of the workers, which can easily lead to substandard product purity and incomplete impurity removal. Therefore, improving the precision of carbon dioxide purification has become an urgent technical problem to be solved. Summary of the Invention

[0006] This invention provides a carbon dioxide purification method and system based on temperature-switching adsorption, which aims to meet the needs of industrial production and improve the accuracy and efficiency of carbon dioxide purification.

[0007] To achieve the above objectives, the present invention provides a carbon dioxide purification method based on temperature-switching adsorption, comprising: The pre-acquired industrial-grade carbon dioxide feed gas is subjected to condensate impurity removal treatment to obtain carbon dioxide pretreated feed gas. The carbon dioxide pretreatment feed gas is subjected to desulfurization treatment to obtain carbon dioxide desulfurization process gas; The carbon dioxide desulfurization process gas is subjected to temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas. The low-impurity carbon dioxide process gas is subjected to distillation to remove heavy components, thereby obtaining refined carbon dioxide gas; The refined carbon dioxide gas is cooled and liquefied to obtain electronic-grade liquid carbon dioxide.

[0008] Optionally, the step of removing condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain pre-treated carbon dioxide feed gas includes: The industrial-grade carbon dioxide feed gas was subjected to component analysis to obtain data on the impurity content of the feed gas. Based on the impurity content data of the raw gas, determine the impurity removal parameters for the raw gas; Based on the impurity removal parameters of the raw material gas, the industrial-grade carbon dioxide raw material gas is pressurized and cooled to obtain carbon dioxide pretreated raw material gas.

[0009] Optionally, the raw material gas impurity removal parameters include a compressor boosting pressure threshold and a cooler cooling temperature threshold; the step of pressurizing and cooling the industrial-grade carbon dioxide raw material gas based on the raw material gas impurity removal parameters to obtain carbon dioxide pretreated raw material gas includes: Based on the compressor boosting pressure threshold, the industrial-grade carbon dioxide feed gas is subjected to staged compressor boosting to obtain boosted carbon dioxide feed gas. Based on the cooling temperature threshold of the cooler, the carbon dioxide pressurized feed gas is subjected to gradient cooling by the cooler to obtain carbon dioxide cooled feed gas. The carbon dioxide cooling feed gas is subjected to gas-liquid separation to obtain carbon dioxide pretreated feed gas.

[0010] Optionally, the desulfurization treatment of the carbon dioxide pretreatment feed gas to obtain carbon dioxide desulfurization process gas includes: Based on a pre-constructed hydrolysis purification tower, the carbon dioxide pretreatment raw gas is hydrolyzed to obtain carbon dioxide hydrolysis process gas. Based on the pre-constructed coarse desulfurization tower, the carbon dioxide hydrolysis process gas is subjected to coarse desulfurization treatment to obtain carbon dioxide coarse desulfurization process gas. Based on the pre-constructed fine desulfurization tower, the carbon dioxide crude desulfurization process gas is subjected to deep desulfurization treatment to obtain carbon dioxide desulfurization process gas.

[0011] Optionally, the step of subjecting the carbon dioxide desulfurization process gas to temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas includes: Based on the pre-constructed dehydrocarbonization purification tower, the carbon dioxide desulfurization process gas is subjected to dehydrocarbonization treatment to obtain carbon dioxide dehydrocarbonization process gas. Based on a pre-constructed adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to impurity adsorption treatment to obtain carbon dioxide adsorbed process gas. The carbon dioxide adsorption process gas was subjected to trace water and small molecule hydrocarbon detection to obtain the adsorption process gas index detection compliance information; Based on the compliance information of the adsorption process gas indicators, the carbon dioxide adsorption process gas is collected to obtain low-impurity carbon dioxide process gas.

[0012] Optionally, the adsorption tower includes an activated alumina adsorption tower and a 3A molecular sieve adsorption tower; The pre-constructed adsorption tower is used to adsorb impurities from the carbon dioxide dehydrocarbonization process gas to obtain carbon dioxide adsorbed process gas, including: The hydrocarbon content of the carbon dioxide dehydrogenation process gas was tested to obtain hydrocarbon content compliance information; Based on the hydrocarbon content detection compliance information and the activated alumina adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to polar impurity adsorption treatment to obtain carbon dioxide crude dehydration process gas. Based on the 3A molecular sieve adsorption tower, the carbon dioxide crude dehydration process gas is subjected to small molecule hydrocarbon adsorption treatment to obtain carbon dioxide adsorbed process gas.

[0013] Optionally, the step of distilling the low-impurity carbon dioxide process gas to remove heavy components and obtain refined carbon dioxide gas includes: Based on a pre-constructed precision filter, the low-impurity carbon dioxide process gas is filtered for solid and colloidal impurities to obtain carbon dioxide filtered process gas. Based on the pre-constructed dual purification tower, the carbon dioxide filtration process gas is subjected to distillation separation to obtain distilled gaseous phase and bottom liquid. Based on the liquid in the reactor, the gaseous phase after distillation is collected to obtain purified carbon dioxide gas.

[0014] Optionally, the step of collecting the distilled gaseous phase based on the reactor liquid to obtain purified carbon dioxide gas includes: The liquid in the reactor is subjected to multi-index testing to obtain multi-index testing information of the liquid in the reactor, wherein the multi-index testing information of the liquid in the reactor includes information on whether the liquid in the reactor meets the standards or information on whether the liquid in the reactor does not meet the standards. Based on the multi-index compliance information of the reactor liquid, the gaseous phase after distillation is purified and collected to obtain refined carbon dioxide gas. Based on the information that the multiple indicators of the reactor liquid did not meet the standards, the reactor liquid was subjected to cyclic distillation and testing until the information of the multiple indicators of the reactor liquid met the standards, and gaseous matter was collected to obtain purified carbon dioxide gas.

[0015] Optionally, the cooling and liquefaction treatment of the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide includes: The purity of the refined carbon dioxide gas was tested to obtain purity test data; Based on the purity test data, the condenser cooling liquefaction temperature parameters and condenser pressure parameters are determined. Based on the condenser cooling liquefaction temperature parameters and condenser pressure parameters, the refined carbon dioxide gas is subjected to gradient cooling liquefaction to obtain electronic-grade liquid carbon dioxide.

[0016] To achieve the above objectives, the present invention also provides a carbon dioxide purification system based on temperature-switching adsorption, which employs the above-mentioned carbon dioxide purification method based on temperature-switching adsorption, comprising: The preliminary impurity removal module is used to remove condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain pre-treated carbon dioxide feed gas. The gas desulfurization module is used to desulfurize the carbon dioxide pretreated raw gas to obtain carbon dioxide desulfurization process gas. The temperature-switching adsorption treatment module is used to perform temperature-switching adsorption treatment on the carbon dioxide desulfurization process gas to obtain low-impurity carbon dioxide process gas. The gas distillation and heavy removal module is used to distill and remove heavy components from the low-impurity carbon dioxide process gas to obtain refined carbon dioxide gas, and to cool and liquefy the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide.

[0017] The present invention also provides an electronic device, the electronic device comprising: Memory, storing at least one instruction; and The processor executes the instructions stored in the memory to implement the carbon dioxide purification method based on temperature-switching adsorption described above.

[0018] The purification method and system of the present invention have the following advantages.

[0019] This invention involves treating pre-acquired industrial-grade carbon dioxide feed gas to remove condensate impurities, resulting in pre-treated carbon dioxide feed gas. This reduces the impurity load on the carbon dioxide purification process. The pre-treated feed gas is then desulfurized to obtain desulfurized process gas, ensuring complete removal of sulfur-containing impurities from gaseous carbon dioxide. Next, the desulfurized process gas undergoes temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas, achieving efficient removal of hydrocarbons and moisture, further purifying the carbon dioxide gas. Subsequently, the low-impurity carbon dioxide process gas is distilled to remove heavy components, yielding refined carbon dioxide gas, further improving its purity. Finally, the refined carbon dioxide gas is cooled and liquefied to obtain electronic-grade liquid carbon dioxide. This process ensures high purity of the electronic-grade liquid carbon dioxide, guarantees the product morphology meets application requirements, and improves the stability and reliability of large-scale industrial production. It is energy-saving, environmentally friendly, suitable for large-scale industrial production, and enhances production efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of a carbon dioxide purification method based on temperature-switching adsorption provided in an embodiment of the present invention. Figure 2 A functional block diagram of a carbon dioxide purification system based on temperature-switching adsorption provided in an embodiment of the present invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] This application provides a carbon dioxide purification method based on temperature-switching adsorption. The execution entity of the carbon dioxide purification method based on temperature-switching adsorption includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the carbon dioxide purification method based on temperature-switching adsorption can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0023] Reference Figure 1 The diagram shown is a schematic flow chart of a carbon dioxide purification method based on temperature-switching adsorption according to an embodiment of the present invention. In this embodiment, the carbon dioxide purification method based on temperature-switching adsorption includes: S1. The pre-acquired industrial-grade carbon dioxide feed gas is subjected to condensate impurity removal treatment to obtain carbon dioxide pretreated feed gas.

[0024] Industrial-grade carbon dioxide feedstock gas refers to carbon dioxide gas containing impurities such as sulfur compounds, hydrocarbons, moisture, and solid particles, whose purity does not meet the standards for electronic-grade use, and can originate from carbon dioxide gas generated during industrial production processes. Pretreated carbon dioxide feedstock gas is carbon dioxide feedstock gas with significantly reduced impurity content in the condensate.

[0025] In this embodiment, the industrial-grade carbon dioxide feed gas can first be subjected to component detection to determine the types and contents of impurities. Then, based on the detection results including the types and contents of impurities, appropriate compressor boosting pressure thresholds and cooler cooling temperature thresholds are determined. Subsequently, according to the aforementioned appropriate compressor boosting pressure thresholds, the industrial-grade carbon dioxide feed gas is boosted in stages using a multi-stage compressor to obtain boosted feed gas. Then, according to the aforementioned appropriate cooler cooling temperature thresholds, the boosted feed gas is subjected to gradient cooling using a cooler, gradually converting some impurities in the boosted feed gas into condensate. Finally, the condensate converted from these impurities is separated from the remaining gas using a gas-liquid separation device to obtain pretreated carbon dioxide feed gas.

[0026] Specifically, the process of removing condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain pre-treated carbon dioxide feed gas includes: The industrial-grade carbon dioxide feed gas was subjected to component analysis to obtain data on the impurity content of the feed gas. Based on the impurity content data of the raw gas, determine the impurity removal parameters for the raw gas; Based on the impurity removal parameters of the raw material gas, the industrial-grade carbon dioxide raw material gas is pressurized and cooled to obtain carbon dioxide pretreated raw material gas.

[0027] Understandably, the data on impurity content in raw gas refers to quantitative information that reflects the specific content of various impurities in industrial-grade carbon dioxide raw gas.

[0028] Raw gas impurity removal parameters refer to key process parameters determined based on raw gas impurity content data, used to guide impurity removal treatment. Raw gas impurity removal parameters mainly include compressor boost pressure threshold and cooler cooling temperature threshold.

[0029] This application embodiment can employ detection equipment such as gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS) to comprehensively analyze the combined components of industrial-grade carbon dioxide feedstock gas. The analysis focuses on the types of impurities such as sulfur compounds, hydrocarbons, moisture, nitrogen, and oxygen in the industrial-grade carbon dioxide feedstock gas, and the precise determination of the content values ​​of each impurity. Simultaneously, the initial purity of carbon dioxide in the industrial-grade carbon dioxide feedstock gas is recorded. Then, all the combined component detection results are compiled and summarized to form complete data on the impurity content of the feedstock gas, providing a reference for determining the impurity removal parameters of the industrial-grade carbon dioxide feedstock gas.

[0030] Then, by combining the content of various impurities in the raw gas impurity content data, and referring to the requirements of desulfurization, adsorption and other processes on the state of industrial-grade carbon dioxide raw gas, and by comprehensively considering the thermodynamic conditions of impurity condensation and conversion and equipment operating efficiency, as well as by process simulation calculation or comparison with historical data, appropriate compressor boosting pressure threshold and cooler cooling temperature threshold can be determined as raw gas impurity removal parameters. This ensures that after boosting and cooling, impurities in industrial-grade carbon dioxide raw gas can be converted into condensate to the greatest extent, while avoiding energy waste caused by excessive boosting or cooling.

[0031] Following this, in the purification system, industrial-grade carbon dioxide feed gas is fed into a multi-stage compressor according to a predetermined compressor boosting pressure threshold. Then, the pressure of the industrial-grade carbon dioxide feed gas is gradually increased to reach the compressor boosting pressure threshold through a step-by-step pressurization process, avoiding sudden pressure increases that could lead to unstable gas properties or equipment damage. Subsequently, the pressurized industrial-grade carbon dioxide feed gas is fed into a cooler, and the temperature of the pressurized industrial-grade carbon dioxide feed gas is gradually reduced using a gradient cooling method according to a predetermined cooler cooling temperature threshold, causing impurities such as moisture and some hydrocarbons to condense into condensate. Finally, the condensate formed by these impurities is separated from the gas whose main component is carbon dioxide through a gas-liquid separation device, and the separated gas is collected, which is the carbon dioxide pretreatment feed gas.

[0032] Specifically, the raw material gas impurity removal parameters include the compressor boost pressure threshold and the cooler cooling temperature threshold; The process of pressurizing and cooling the industrial-grade carbon dioxide feed gas based on the impurity removal parameters to obtain pretreated carbon dioxide feed gas includes: Based on the compressor boosting pressure threshold, the industrial-grade carbon dioxide feed gas is subjected to staged compressor boosting to obtain boosted carbon dioxide feed gas. Based on the cooling temperature threshold of the cooler, the carbon dioxide pressurized feed gas is subjected to gradient cooling by the cooler to obtain carbon dioxide cooled feed gas. The carbon dioxide cooling feed gas is subjected to gas-liquid separation to obtain carbon dioxide pretreated feed gas.

[0033] Understandably, the compressor boost pressure threshold refers to the final compressor boost pressure standard determined by combining the impurity content data of the raw material gas to facilitate the condensation and separation of target impurities in the industrial-grade carbon dioxide feed gas.

[0034] The cooler cooling temperature threshold refers to the final cooling value standard of the cooler, which is determined based on the impurity content data and impurity condensation characteristics of the raw material gas to promote the conversion of impurities in industrial-grade carbon dioxide feed gas into condensate.

[0035] Carbon dioxide boosted feedstock gas refers to the gaseous product of industrial-grade carbon dioxide feedstock gas after being boosted by a compressor in stages until the pressure reaches a preset boosting pressure threshold. It is important to know that the physical state of carbon dioxide boosted feedstock gas is more conducive to the condensation and separation of impurities during the subsequent cooling process.

[0036] Carbon dioxide cooled feedstock gas refers to the gaseous product whose temperature drops to a preset cooling temperature threshold after being cooled by a gradient cooling device.

[0037] This embodiment of the application can, after checking the operating status of the multi-stage compressor and ensuring stable equipment performance, divide the pressurization process of the multi-stage compressor into multiple gradient stages according to the aforementioned compressor pressurization pressure threshold. For example, if the compressor pressurization pressure threshold is 25 bar, it can be divided into three stages of 10 bar, 18 bar, and 25 bar to gradually increase the pressure. Then, industrial-grade carbon dioxide feed gas is continuously fed into the multi-stage compressor, and through the step-by-step compression action inside the multi-stage compressor equipment, the feed gas pressure is steadily increased to the compressor pressurization pressure threshold, so as to obtain pressurized carbon dioxide feed gas with the required pressure. This avoids the change in the form of impurities in the industrial-grade carbon dioxide feed gas or the wear and tear of the multi-stage compressor equipment caused by a sudden increase in pressure.

[0038] Next, based on the cooling temperature threshold of the cooler and the initial temperature of the carbon dioxide pressurized feed gas, a gradient cooling program for the cooler can be set. For example, if the cooling temperature threshold of the cooler is 5°C and the initial temperature of the carbon dioxide pressurized feed gas is 40°C, three cooling stages of 30°C, 15°C, and 5°C can be set. Subsequently, the carbon dioxide pressurized feed gas is introduced into the cooler, and the temperature is gradually reduced through heat exchange between the cooling medium and the carbon dioxide pressurized feed gas. The temperature of the carbon dioxide pressurized feed gas is monitored in real time during the cooling process to ensure a stable temperature transition at each stage and to avoid rapid cooling that could cause water in the carbon dioxide pressurized feed gas to freeze or impurities to condense unevenly, ultimately obtaining carbon dioxide cooled feed gas with the required temperature.

[0039] After this, the gradient-cooled carbon dioxide cooling feed gas can be passed into a gas-liquid separation device. The density difference between the carbon dioxide cooling feed gas and the condensate can be used to make the carbon dioxide cooling feed gas rise in the gas-liquid separation device, while the condensate settles to the bottom of the device due to gravity. At the same time, the separation effect can be further enhanced by the separation components inside the gas-liquid separation device, avoiding the condensate from being carried with the gas. The condensate impurities collected at the bottom of the gas-liquid separation device are periodically discharged, and the separated gas is then collected. This is the carbon dioxide pretreated feed gas with most of the condensate impurities removed.

[0040] S2. The carbon dioxide pretreatment raw gas is subjected to desulfurization treatment to obtain carbon dioxide desulfurization process gas.

[0041] Understandably, carbon dioxide desulfurization process gas refers to carbon dioxide gas that has undergone desulfurization treatment and whose sulfur impurity content meets the requirements of subsequent processes.

[0042] In this embodiment, carbon dioxide pretreated feed gas is passed into a hydrolysis purification tower filled with HT503 type hydrolysis catalyst, and the temperature and space velocity are controlled to generate suitable conditions. This allows organic sulfur compounds such as carbonyl sulfide and carbon disulfide in the carbon dioxide pretreated feed gas to be hydrolyzed into easily removed hydrogen sulfide, resulting in carbon dioxide hydrolysis process gas. Then, the carbon dioxide hydrolysis process gas is passed into a coarse desulfurization tower filled with KH314 type composite iron oxide desulfurizing agent. Through chemical adsorption, most of the hydrogen sulfide in the carbon dioxide hydrolysis process gas can be removed, resulting in coarse carbon dioxide desulfurization process gas. Finally, the coarse carbon dioxide desulfurization process gas is passed into a fine desulfurization tower filled with H310 type fine desulfurizing agent for deep desulfurization treatment, which can reduce the total sulfur content in the coarse carbon dioxide desulfurization process gas to the ppb level, thus obtaining carbon dioxide desulfurization process gas.

[0043] Specifically, the desulfurization treatment of the carbon dioxide pretreatment feed gas to obtain carbon dioxide desulfurization process gas includes: Based on a pre-constructed hydrolysis purification tower, the carbon dioxide pretreatment raw gas is hydrolyzed to obtain carbon dioxide hydrolysis process gas. Based on the pre-constructed coarse desulfurization tower, the carbon dioxide hydrolysis process gas is subjected to coarse desulfurization treatment to obtain carbon dioxide coarse desulfurization process gas. Based on the pre-constructed fine desulfurization tower, the carbon dioxide crude desulfurization process gas is subjected to deep desulfurization treatment to obtain carbon dioxide desulfurization process gas.

[0044] Understandably, a hydrolysis purification tower is a specialized device that is filled with a specific hydrolysis catalyst to convert organic sulfur in carbon dioxide gas into inorganic sulfur.

[0045] Carbon dioxide hydrolysis process gas refers to carbon dioxide gas that has been converted from organic sulfur to inorganic sulfur through hydrolysis treatment.

[0046] A coarse desulfurization tower is a specialized device that is filled with a large capacity of desulfurizing agent to remove most of the inorganic sulfur impurities from carbon dioxide gas.

[0047] The carbon dioxide crude desulfurization process gas refers to carbon dioxide gas that has undergone crude desulfurization treatment, in which most of the inorganic sulfur impurities have been removed. It is important to know that the carbon dioxide crude desulfurization process gas is not sulfur-free, but rather has a very low sulfur content.

[0048] A fine desulfurization tower is a specialized device that is filled with high-precision desulfurizing agent to reduce residual sulfur-containing impurities in carbon dioxide gas to extremely low levels.

[0049] In this embodiment, a sufficient amount of HT503 hydrolysis catalyst is first loaded into the hydrolysis purification tower. Then, the carbon dioxide pretreated feed gas is continuously introduced into the hydrolysis purification tower, and the temperature inside the tower is controlled within the catalyst's active temperature window. At the same time, the gas space velocity of the carbon dioxide pretreated feed gas is adjusted to ensure sufficient contact between the carbon dioxide pretreated feed gas and the HT503 hydrolysis catalyst. Under the catalytic action of the HT503 hydrolysis catalyst, organic sulfur compounds such as carbonyl sulfide and carbon disulfide in the carbon dioxide pretreated feed gas undergo hydrolysis reactions and are converted into hydrogen sulfide and carbon dioxide. At this time, the carbon dioxide gas at the outlet of the hydrolysis purification tower is collected to obtain the carbon dioxide hydrolysis process gas.

[0050] Next, the carbon dioxide hydrolysis process gas is introduced into the coarse desulfurization tower filled with KH314 composite iron oxide desulfurizing agent, and the gas flow rate of the carbon dioxide hydrolysis process gas is controlled to ensure that the carbon dioxide hydrolysis process gas and the KH314 composite iron oxide desulfurizing agent are in full contact. The iron oxide in the KH314 composite iron oxide desulfurizing agent undergoes a chemical adsorption reaction with the hydrogen sulfide in the carbon dioxide hydrolysis process gas, which can generate iron sulfide compounds, thereby removing most of the hydrogen sulfide impurities in the carbon dioxide hydrolysis process gas, thus forming the coarse carbon dioxide desulfurization process gas.

[0051] Finally, the coarse carbon dioxide desulfurization process gas is introduced into a fine desulfurization tower filled with H310 type fine desulfurizing agent. The pressure and temperature inside the fine desulfurization tower are controlled within a suitable range, allowing the coarse carbon dioxide desulfurization process gas to slowly pass through the desulfurizing agent bed of the fine desulfurization tower. It should be noted that the H310 type fine desulfurizing agent selectively adsorbs residual trace amounts of hydrogen sulfide and some organic sulfur impurities in the coarse carbon dioxide desulfurization process gas. When the total sulfur content in the coarse carbon dioxide desulfurization process gas is reduced to below ppb level, meeting the sulfur content requirements of electronic grade feed gas, carbon dioxide desulfurization process gas can be obtained.

[0052] S3. Perform temperature-switched adsorption treatment on the carbon dioxide desulfurization process gas to obtain low-impurity carbon dioxide process gas.

[0053] Understandably, low-impurity carbon dioxide process gas refers to carbon dioxide gas that has undergone temperature-switched adsorption treatment, resulting in a significant reduction in the content of impurities such as hydrocarbons and moisture.

[0054] In this embodiment, the carbon dioxide desulfurization process gas is first passed into a dehydrogenation purification tower filled with CC-20 catalyst. Then, the reaction temperature inside the dehydrogenation purification tower is adjusted to catalyze and remove most of the light hydrocarbon impurities in the carbon dioxide desulfurization process gas, resulting in carbon dioxide dehydrogenated process gas. Next, the hydrocarbon content of the carbon dioxide dehydrogenated process gas is tested. After confirming that the hydrocarbon content in the carbon dioxide dehydrogenated process gas meets the standard, the carbon dioxide dehydrogenated process gas is passed into an activated alumina adsorption tower to remove most of the moisture and polar impurities, resulting in crude carbon dioxide dehydrated process gas. Then, the crude carbon dioxide dehydrated process gas is passed into a 3A molecular sieve adsorption tower. Utilizing the pore size selectivity of the molecular sieve in the 3A molecular sieve adsorption tower, the remaining moisture and small molecule hydrocarbons in the crude carbon dioxide dehydrated process gas are deeply removed, resulting in carbon dioxide adsorbed process gas. Finally, the carbon dioxide adsorbed process gas is tested for trace water and small molecule hydrocarbons. After confirming that the content of trace water and small molecule hydrocarbons meets the standard, the carbon dioxide adsorbed process gas is collected to obtain low-impurity carbon dioxide process gas.

[0055] Specifically, the temperature-switched adsorption treatment of the carbon dioxide desulfurization process gas to obtain low-impurity carbon dioxide process gas includes: Based on the pre-constructed dehydrocarbonization purification tower, the carbon dioxide desulfurization process gas is subjected to dehydrocarbonization treatment to obtain carbon dioxide dehydrocarbonization process gas. Based on a pre-constructed adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to impurity adsorption treatment to obtain carbon dioxide adsorbed process gas. The carbon dioxide adsorption process gas was subjected to trace water and small molecule hydrocarbon detection to obtain the adsorption process gas index detection compliance information; Based on the compliance information of the adsorption process gas indicators, the carbon dioxide adsorption process gas is collected to obtain low-impurity carbon dioxide process gas.

[0056] It is understandable that a dehydrocarbonization purification tower refers to a specialized device that is filled with a dedicated dehydrocarbonization catalyst and is used to remove hydrocarbon impurities from carbon dioxide gas.

[0057] Carbon dioxide dehydrocarbonation process gas refers to carbon dioxide gas whose hydrocarbon impurity content has been significantly reduced after dehydrocarbonation treatment.

[0058] An adsorption tower is a specialized device filled with a specific adsorbent to remove moisture, polar impurities, and small molecule hydrocarbons from carbon dioxide gas. Adsorption towers typically include activated alumina adsorption towers and 3A molecular sieve adsorption towers.

[0059] Carbon dioxide adsorption process gas refers to carbon dioxide gas that has undergone impurity adsorption treatment, after which most of the remaining impurities have been removed. It should be noted that the purity of carbon dioxide adsorption process gas is close to electronic grade standards and needs to be verified through testing to ensure compliance.

[0060] Adsorption process gas index detection compliance information refers to the judgment information formed after confirming that the content of both types of impurities in the gas meets the preset standards through the detection of trace water and small molecule hydrocarbons.

[0061] In this embodiment, a sufficient amount of CC-20 catalyst is first loaded into the dehydrogenation purification tower, and then the carbon dioxide desulfurization process gas is continuously fed into the dehydrogenation purification tower. Thus, based on the activity characteristics of the CC-20 catalyst, the reaction temperature inside the dehydrogenation purification tower can be controlled within a suitable range. At the same time, the gas flow rate of the carbon dioxide desulfurization process gas is adjusted to ensure that the carbon dioxide desulfurization process gas and the CC-20 catalyst are in full contact. At this time, under the catalytic action of the CC-20 catalyst, most of the light hydrocarbons, non-methane total hydrocarbons and other hydrocarbon impurities in the carbon dioxide desulfurization process gas are removed. The gas at the outlet of the dehydrogenation purification tower is then collected to obtain the carbon dioxide dehydrogenation process gas.

[0062] Furthermore, the carbon dioxide dehydrogenation process gas is first passed into an adsorption tower filled with activated alumina. Activated alumina, with its large specific surface area and abundant pore structure, can adsorb most of the moisture and some polar impurities in the carbon dioxide dehydrogenation process gas, thus initially reducing the impurity load of the carbon dioxide dehydrogenation process gas. Subsequently, the carbon dioxide dehydrogenation process gas that has undergone preliminary adsorption is passed into an adsorption tower filled with 3A molecular sieve. 3A molecular sieve has a uniform pore size distribution, which can accurately adsorb the remaining trace amounts of moisture and small molecule hydrocarbons in the carbon dioxide dehydrogenation process gas, thereby achieving deep removal of impurities and obtaining carbon dioxide adsorbed process gas.

[0063] Next, a high-precision trace moisture analyzer and hydrocarbon analyzer can be used to sample and test the carbon dioxide adsorption process gas. The content of trace moisture and the total content of small molecule hydrocarbons in the carbon dioxide adsorption process gas are measured respectively. The test results of trace moisture content and total content of small molecule hydrocarbons are then compared with the pre-set electronic grade raw material gas impurity standards. If the content of trace moisture and total content of small molecule hydrocarbons are both lower than the electronic grade raw material gas impurity standards, the test is judged to be compliant, thus generating information on compliance of adsorption process gas indicators.

[0064] After confirming that the trace moisture content and total small molecule hydrocarbon content are both below the electronic-grade feed gas impurity standards, and generating information indicating that the adsorption process gas indicators meet the standards, the valve of the gas collection pipeline can be opened. This pipeline can then be used to continuously introduce the compliant carbon dioxide adsorption process gas into a dedicated gas storage container or directly to the feed pipeline of the distillation process, thus obtaining low-impurity carbon dioxide process gas. It is important to note that during the collection of the compliant carbon dioxide adsorption process gas, the gas flow rate and pressure need to be monitored in real time and kept stable.

[0065] It should be noted that the above-mentioned adsorption towers include activated alumina adsorption towers and 3A molecular sieve adsorption towers; The pre-constructed adsorption tower is used to adsorb impurities from the carbon dioxide dehydrocarbonization process gas to obtain carbon dioxide adsorbed process gas, including: The hydrocarbon content of the carbon dioxide dehydrogenation process gas was tested to obtain hydrocarbon content compliance information; Based on the hydrocarbon content detection compliance information and the activated alumina adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to polar impurity adsorption treatment to obtain carbon dioxide crude dehydration process gas. Based on the 3A molecular sieve adsorption tower, the carbon dioxide crude dehydration process gas is subjected to small molecule hydrocarbon adsorption treatment to obtain carbon dioxide adsorbed process gas.

[0066] Understandably, an activated alumina adsorption tower refers to a specialized adsorption device that is filled with activated alumina adsorbent and used for coarse dehydration and adsorption of polar impurities.

[0067] A 3A molecular sieve adsorption tower is a specialized adsorption device filled with 3A molecular sieve adsorbent for deep dehydration and adsorption of small molecule hydrocarbons.

[0068] Hydrocarbon content detection compliance information refers to the judgment information formed after confirming that the content of hydrocarbon impurities in the gas is lower than a preset threshold through hydrocarbon content detection.

[0069] The carbon dioxide crude dehydration process gas refers to carbon dioxide gas that has had most of its moisture and polar impurities removed after being treated by an activated alumina adsorption tower.

[0070] This application embodiment can use a high-precision hydrocarbon analyzer to sample and test the carbon dioxide dehydrogenation process gas, which can determine the content of non-methane total hydrocarbons in the carbon dioxide dehydrogenation process gas. At the same time, a detection threshold is set with reference to the hydrocarbon impurity standard of electronic-grade carbon dioxide. Then, the measured non-methane total hydrocarbon content is compared with the detection threshold. If the non-methane total hydrocarbon content is lower than the detection threshold, the dehydrogenation treatment effect is determined to be up to standard, thus forming hydrocarbon content detection compliance information. If the non-methane total hydrocarbon content is higher than or equal to the detection threshold, the carbon dioxide dehydrogenation process gas is returned to the dehydrogenation purification tower for reprocessing until the detection meets the standard.

[0071] After confirming that the non-methane hydrocarbon content in the carbon dioxide dehydrogenation process gas meets the standards, the carbon dioxide dehydrogenation process gas can be continuously fed into the activated alumina adsorption tower. At the same time, the gas flow rate of the carbon dioxide dehydrogenation process gas is controlled within an appropriate range to ensure that the carbon dioxide dehydrogenation process gas is in full contact with the adsorbent bed in the activated alumina adsorption tower. This avoids insufficient adsorption due to excessive flow rate. The activated alumina in the activated alumina adsorption tower can capture most of the moisture and some polar macromolecular impurities in the carbon dioxide dehydrogenation process gas through physical adsorption. Therefore, through the above process, a crude dehydrated carbon dioxide process gas with significantly reduced moisture and polar impurity content can be obtained.

[0072] Finally, the carbon dioxide crude dehydration process gas is passed into a 3A molecular sieve adsorption tower with a uniform pore structure. At the same time, the temperature and pressure inside the 3A molecular sieve adsorption tower are controlled within a suitable physical adsorption range to promote impurity adsorption. Then, the 3A molecular sieve in the 3A molecular sieve adsorption tower can be used to precisely adsorb the residual trace moisture and small molecule hydrocarbons in the carbon dioxide crude dehydration process gas, ultimately obtaining carbon dioxide adsorbed process gas with extremely low impurity content.

[0073] S4. The low-impurity carbon dioxide process gas is subjected to distillation to remove heavy components, thereby obtaining refined carbon dioxide gas.

[0074] Understandably, refined carbon dioxide gas refers to gaseous carbon dioxide that has undergone distillation to remove heavy components, and whose purity and impurity content meet the requirements for electronic grade.

[0075] In this embodiment, low-impurity carbon dioxide process gas is first passed through a precision filter to remove solid particles and colloidal impurities, resulting in filtered carbon dioxide process gas. Then, the filtered carbon dioxide process gas is passed through a dual purification tower, and the temperature and pressure parameters of the tower are adjusted to cause the filtered carbon dioxide process gas to expand, vaporize, and undergo distillation separation, yielding a distilled gaseous phase and a bottom liquid. Next, the bottom liquid undergoes multi-index testing. If the multi-index tests in the bottom liquid meet the standards, the distilled gaseous phase is directly collected to obtain purified carbon dioxide gas. If the tests fail to meet the standards, the bottom liquid is returned to the feed end of the dual purification tower for repeated distillation separation and multi-index testing until the multi-index tests in the bottom liquid meet the standards again, at which point the distilled gaseous phase is collected to obtain purified carbon dioxide gas.

[0076] Specifically, the process of removing heavy components from the low-impurity carbon dioxide process gas by distillation to obtain refined carbon dioxide gas includes: Based on a pre-constructed precision filter, the low-impurity carbon dioxide process gas is filtered for solid and colloidal impurities to obtain carbon dioxide filtered process gas. Based on the pre-constructed dual purification tower, the carbon dioxide filtration process gas is subjected to distillation separation to obtain distilled gaseous phase and bottom liquid. Based on the liquid in the reactor, the gaseous phase after distillation is collected to obtain purified carbon dioxide gas.

[0077] Understandably, a precision filter refers to a specialized device with high-precision filtration performance used to remove solid particles and colloidal impurities from gases.

[0078] Carbon dioxide filtration process gas refers to carbon dioxide gas that has undergone precision filtration to remove solid and colloidal impurities.

[0079] A twin purification tower is a specialized distillation device consisting of two distillation towers working together to achieve efficient separation of carbon dioxide gas from heavy component impurities.

[0080] The gaseous phase after distillation refers to the gaseous product formed when carbon dioxide gas with a low boiling point rises to the top of the column during the distillation separation process.

[0081] Bottom liquid refers to the liquid product formed when heavy impurities with higher boiling points settle to the bottom of the distillation column during the distillation process.

[0082] In this embodiment, low-impurity carbon dioxide process gas can be continuously fed through a high-precision filter. At the same time, the gas flow rate of the low-impurity carbon dioxide process gas is controlled within a preset range to avoid excessive flow rate causing blockage of the filter medium in the precision filter or impurity penetration. It should be noted that the filter medium captures mechanical impurities such as solid particles and colloids entrained in the low-impurity carbon dioxide process gas through physical interception, which can prevent such impurities from entering the distillation column in subsequent processes, causing scaling on the trays or a decrease in separation efficiency. Then, the gas at the outlet of the precision filter is collected to obtain clean carbon dioxide filtered process gas.

[0083] Then, the pre-constructed dual purification tower is preheated and debugged to ensure stable operation. The carbon dioxide filtration process gas is then introduced into the preheated and debugged dual purification tower, and the distillation temperature and pressure parameters inside the dual purification tower are adjusted to cause the carbon dioxide filtration process gas to expand and vaporize inside the dual purification tower and undergo gas-liquid countercurrent contact. At this time, because the carbon dioxide has a lower boiling point, it will rise to the top of the dual purification tower to form the distilled gaseous phase, while the heavy component impurities, because of their higher boiling point, will settle to the bottom of the dual purification tower to form the bottom liquid. Therefore, the distilled gaseous phase and the bottom liquid can be collected separately through the gas phase outlet at the top of the dual purification tower and the bottom liquid outlet, ensuring that the two types of products are completely separated without mutual entrainment.

[0084] During the collection of the bottom liquid, it is necessary to continuously monitor the changes in the liquid level and composition of the bottom liquid in the column. Combined with the stability of the distillation process parameters, the distillation separation effect of the carbon dioxide filtration process gas can be judged. If the bottom liquid level is in the normal range and the composition is stable, it indicates that the heavy component impurities have been completely removed. The distilled gas phase can be directly collected through the gas phase collection pipeline at the top of the dual purification column to form refined carbon dioxide gas.

[0085] Specifically, the step of collecting the distilled gaseous phase based on the reactor liquid to obtain purified carbon dioxide gas includes: The liquid in the reactor is subjected to multi-index testing to obtain multi-index testing information of the liquid in the reactor, wherein the multi-index testing information of the liquid in the reactor includes information on whether the liquid in the reactor meets the standards or information on whether the liquid in the reactor does not meet the standards. Based on the multi-index compliance information of the reactor liquid, the gaseous phase after distillation is purified and collected to obtain refined carbon dioxide gas. Based on the information that the multiple indicators of the reactor liquid did not meet the standards, the reactor liquid was subjected to cyclic distillation and testing until the information of the multiple indicators of the reactor liquid met the standards, and gaseous matter was collected to obtain purified carbon dioxide gas.

[0086] Understandably, the multi-index detection information of the reactor liquid refers to the general term for various index data and judgment results obtained after multi-index detection of the reactor liquid. The multi-index detection information of the reactor liquid can be divided into two categories: reactor liquid multi-index compliance information and reactor liquid multi-index non-compliance information.

[0087] The multi-index compliance information of the still liquid refers to the judgment information formed after the carbon dioxide purity and the content of various impurities of the still liquid meet the preset electronic grade standards. It should be noted that the multi-index compliance information of the still liquid is a prerequisite for directly collecting the gaseous phase after distillation.

[0088] The information indicating that multiple indicators of the still liquid do not meet the standards refers to the judgment information formed when the carbon dioxide purity or the content of a certain type of impurity in the still liquid does not meet the preset electronic grade standards. It should be noted that the information indicating that multiple indicators of the still liquid do not meet the standards is the trigger for the still liquid to undergo cyclic distillation testing.

[0089] In this embodiment, after extracting a sample of the bottom liquid from the double purification tower, a gas chromatograph, a trace impurity analyzer, and other equipment can be used to perform multi-index testing on the bottom liquid sample. These multi-index tests include the purity of carbon dioxide in the bottom liquid, the total sulfur content in the bottom liquid, the water content in the bottom liquid, and the hydrocarbon content in the bottom liquid. Then, each test data of the bottom liquid sample is compared with a preset electronic standard. If all test data meet the standard, multi-index compliance information of the bottom liquid is generated. If any one of the test data does not meet the standard, multi-index non-compliance information of the bottom liquid is generated.

[0090] When the multi-index detection information of the bottom liquid shows that the bottom liquid meets the standards, the gas phase purification and collection pipeline at the top of the dual purification tower can be opened, and the pressure and flow parameters of the gas phase purification and collection pipeline can be adjusted to a suitable range to avoid pressure fluctuations or impurity entrainment in the gas phase after distillation during the collection process. Then, the gas phase after distillation is further purified by a dedicated gas phase purification component to remove a small amount of light component impurities. Next, the treated gas phase after distillation is introduced into a high-pressure gas storage tank for collection. After collection, the indicators of the gas phase after distillation in the gas storage tank are checked. After confirming that there are no errors, the gas phase after distillation can be used as purified carbon dioxide gas.

[0091] When the multi-index detection information of the bottom liquid indicates that multiple indicators of the bottom liquid fail to meet the standards, the gaseous phase purification and collection pipeline at the top of the dual purification tower needs to be shut off. Then, the substandard bottom liquid in the bottom of the dual purification tower should be reintroduced into the feed end of the dual purification tower through the reflux pipeline, mixed with the newly input carbon dioxide filtration process gas, and the process parameters such as the rectification temperature, pressure, and reflux ratio in the dual purification tower should be readjusted. The mixed material should be subjected to secondary rectification separation. After the rectification state in the dual purification tower is stable, a newly generated bottom liquid sample should be drawn from the bottom of the tower again for multi-index detection. If the multi-index detection of the bottom liquid sample still fails to meet the standards, the above reflux, rectification, and detection operations should be repeated until the multi-index detection information of the bottom liquid sample indicates that the bottom liquid meets the standards. Then, the gaseous phase after rectification should be purified and collected according to the above operating procedure when the multi-index detection information of the bottom liquid meets the standards, so as to obtain refined carbon dioxide gas.

[0092] S5. The refined carbon dioxide gas is cooled and liquefied to obtain electronic-grade liquid carbon dioxide.

[0093] Electronic-grade liquid carbon dioxide refers to liquid carbon dioxide with extremely high purity and extremely low impurity content, which can be used in high-end electronic fields such as semiconductor manufacturing and optoelectronic device production.

[0094] In this embodiment, the purity of refined carbon dioxide gas is first tested to obtain accurate purity data. Then, based on the purity data and the pre-set quality requirements for electronic-grade liquid carbon dioxide, the cooling liquefaction temperature and pressure parameters of the condenser are determined. The refined carbon dioxide gas is then subjected to gradient cooling liquefaction through the condenser according to the cooling liquefaction temperature and pressure parameters to obtain electronic-grade liquid carbon dioxide.

[0095] Specifically, the cooling and liquefaction treatment of the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide includes: The purity of the refined carbon dioxide gas was tested to obtain purity test data; Based on the purity test data, the condenser cooling liquefaction temperature parameters and condenser pressure parameters are determined. Based on the condenser cooling liquefaction temperature parameters and condenser pressure parameters, the refined carbon dioxide gas is subjected to gradient cooling liquefaction to obtain electronic-grade liquid carbon dioxide.

[0096] Understandably, purity test data refers to the quantitative information on the purity of carbon dioxide and the content of various trace impurities obtained after testing the purity of refined carbon dioxide gas.

[0097] A condenser is a specialized device used to cool gaseous carbon dioxide and convert it into liquid form through heat exchange.

[0098] The cooling liquefaction temperature parameter refers to the final condenser cooling temperature determined based on purity test data, which enables refined carbon dioxide gas to be efficiently converted into liquid without affecting product quality.

[0099] The condenser pressure parameter refers to the internal pressure value of the condenser, which is determined based on purity test data and is adapted to the cooling liquefaction temperature to ensure the smooth liquefaction of carbon dioxide gas.

[0100] This application embodiment can use a high-precision gas chromatograph and a trace impurity analyzer to perform comprehensive purity testing on purified carbon dioxide gas, thereby determining the purity value of carbon dioxide in the purified carbon dioxide gas. At the same time, the content of trace impurities such as sulfur, moisture, and small molecule hydrocarbons in the purified carbon dioxide gas is verified. Then, the measured carbon dioxide purity value and the content of trace impurities such as sulfur, moisture, and small molecule hydrocarbons are compiled into complete purity test data, providing a reference for determining the internal parameters of the condenser.

[0101] Next, by combining the carbon dioxide purity and impurity content data from the purity test, and taking into account the gas-liquid phase change characteristics of carbon dioxide, the product form requirements of electronic-grade liquid carbon dioxide can be considered. Through process simulation calculations and phase change thermodynamic analysis, the appropriate condenser cooling liquefaction temperature can be determined. Then, based on the principle of temperature and pressure compatibility, the corresponding condenser pressure parameters can be determined. This will enable both efficient liquefaction of refined carbon dioxide gas and avoid impurity precipitation or abnormal product form due to improper parameters.

[0102] Finally, the internal pressure of the condenser is adjusted to the aforementioned condenser pressure parameters and kept stable. Then, refined carbon dioxide gas is continuously introduced into the condenser, and the temperature inside the condenser is gradually reduced using a gradient cooling method to avoid sudden temperature drops that could cause localized icing or impurity entrainment in the refined carbon dioxide gas. This continues until the temperature inside the condenser reaches the aforementioned condenser cooling liquefaction temperature parameters and remains stable. At this point, under the synergistic effect of the condenser cooling liquefaction temperature parameters and the condenser pressure parameters, the refined carbon dioxide gas can smoothly complete the gas-liquid phase transition, transforming into a liquid state. After the liquefaction process stabilizes, the liquid carbon dioxide in the condenser is collected; this is electronic-grade liquid carbon dioxide that meets electronic-grade standards. Carbon dioxide purity ≥ 99.999%, volatile hydrocarbon content ≤ 1.0 ppm, and moisture content ≤ 1.6 ppm.

[0103] This invention introduces several significant technological reforms, resulting in substantial advantages. Specifically, it removes condensate impurities from the pre-acquired industrial-grade carbon dioxide feedstock gas to obtain pretreated carbon dioxide feedstock gas, reducing the impurity load for the carbon dioxide purification process. The pretreated feedstock gas is then desulfurized to obtain desulfurized carbon dioxide process gas, ensuring complete removal of sulfur-containing impurities from gaseous carbon dioxide. Next, the desulfurized process gas undergoes temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas, achieving efficient removal of hydrocarbons and moisture, further purifying the carbon dioxide gas. Subsequently, the low-impurity carbon dioxide process gas is distilled to remove heavy components, obtaining refined carbon dioxide gas, further improving its purity. Finally, the refined carbon dioxide gas is cooled and liquefied to obtain electronic-grade liquid carbon dioxide. This process ensures both high purity and low impurity content of the electronic-grade liquid carbon dioxide, guarantees that the product morphology meets application requirements, and improves the stability and reliability of the process.

[0104] like Figure 2 The diagram shown is a functional block diagram of a carbon dioxide purification system based on temperature-switching adsorption provided in an embodiment of the present invention.

[0105] The carbon dioxide purification system 100 based on temperature-switching adsorption described in this invention can be installed in an electronic device. Depending on the functions implemented, the carbon dioxide purification system 100 based on temperature-switching adsorption may include a preliminary impurity removal module 101, a gas desulfurization treatment module 102, a temperature-switching adsorption treatment module 103, and a gas distillation and heavy metal removal module 104. The module described in this invention can also be referred to as a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and which are stored in the memory of the electronic device.

[0106] The impurity preliminary removal module 101 is used to remove condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain carbon dioxide pretreated feed gas. The gas desulfurization module 102 is used to desulfurize the carbon dioxide pretreated raw gas to obtain carbon dioxide desulfurization process gas. The temperature-switching adsorption treatment module 103 is used to perform temperature-switching adsorption treatment on the carbon dioxide desulfurization process gas to obtain low-impurity carbon dioxide process gas. The gas distillation and heavy removal module 104 is used to distill and remove heavy components from the low-impurity carbon dioxide process gas to obtain refined carbon dioxide gas, and to cool and liquefy the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide.

[0107] In detail, the modules in the carbon dioxide purification system 100 based on temperature-switching adsorption described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The method used is the same as the carbon dioxide purification method based on temperature-switching adsorption described above, and can produce the same technical effect, so it will not be repeated here.

[0108] Furthermore, the functional modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in the form of electronic device hardware, or in the form of hardware plus software functional modules.

[0109] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A carbon dioxide purification method based on temperature-switching adsorption, characterized in that, The method includes: The pre-acquired industrial-grade carbon dioxide feed gas is subjected to condensate impurity removal treatment to obtain carbon dioxide pretreated feed gas. The carbon dioxide pretreatment feed gas is subjected to desulfurization treatment to obtain carbon dioxide desulfurization process gas; The carbon dioxide desulfurization process gas is subjected to temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas. The low-impurity carbon dioxide process gas is subjected to distillation to remove heavy components, thereby obtaining refined carbon dioxide gas; The refined carbon dioxide gas is cooled and liquefied to obtain electronic-grade liquid carbon dioxide.

2. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, characterized in that, The process of removing condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain pretreated carbon dioxide feed gas includes: The industrial-grade carbon dioxide feed gas was subjected to component analysis to obtain data on the impurity content of the feed gas. Based on the impurity content data of the raw gas, determine the impurity removal parameters for the raw gas; Based on the impurity removal parameters of the raw material gas, the industrial-grade carbon dioxide raw material gas is pressurized and cooled to obtain carbon dioxide pretreated raw material gas.

3. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 2, characterized in that, The raw gas impurity removal parameters include the compressor boost pressure threshold and the cooler cooling temperature threshold. The process of pressurizing and cooling the industrial-grade carbon dioxide feed gas based on the impurity removal parameters to obtain pretreated carbon dioxide feed gas includes: Based on the compressor boosting pressure threshold, the industrial-grade carbon dioxide feed gas is subjected to staged compressor boosting to obtain boosted carbon dioxide feed gas. Based on the cooling temperature threshold of the cooler, the carbon dioxide pressurized feed gas is subjected to gradient cooling by the cooler to obtain carbon dioxide cooled feed gas. The carbon dioxide cooling feed gas is subjected to gas-liquid separation to obtain carbon dioxide pretreated feed gas.

4. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, characterized in that, The process of desulfurizing the carbon dioxide pretreated feed gas to obtain carbon dioxide desulfurization process gas includes: Based on a pre-constructed hydrolysis purification tower, the carbon dioxide pretreatment raw gas is hydrolyzed to obtain carbon dioxide hydrolysis process gas. Based on the pre-constructed coarse desulfurization tower, the carbon dioxide hydrolysis process gas is subjected to coarse desulfurization treatment to obtain carbon dioxide coarse desulfurization process gas. Based on the pre-constructed fine desulfurization tower, the carbon dioxide crude desulfurization process gas is subjected to deep desulfurization treatment to obtain carbon dioxide desulfurization process gas.

5. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, characterized in that, The process of subjecting the carbon dioxide desulfurization process gas to temperature-switched adsorption treatment to obtain low-impurity carbon dioxide process gas includes: Based on the pre-constructed dehydrocarbonization purification tower, the carbon dioxide desulfurization process gas is subjected to dehydrocarbonization treatment to obtain carbon dioxide dehydrocarbonization process gas. Based on a pre-constructed adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to impurity adsorption treatment to obtain carbon dioxide adsorbed process gas. The carbon dioxide adsorption process gas was subjected to trace water and small molecule hydrocarbon detection to obtain the adsorption process gas index detection compliance information; Based on the compliance information of the adsorption process gas indicators, the carbon dioxide adsorption process gas is collected to obtain low-impurity carbon dioxide process gas.

6. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 5, characterized in that, The adsorption tower includes an activated alumina adsorption tower and a 3A molecular sieve adsorption tower; The pre-constructed adsorption tower is used to adsorb impurities from the carbon dioxide dehydrocarbonization process gas to obtain carbon dioxide adsorbed process gas, including: The hydrocarbon content of the carbon dioxide dehydrogenation process gas was tested to obtain hydrocarbon content compliance information; Based on the hydrocarbon content detection compliance information and the activated alumina adsorption tower, the carbon dioxide dehydrogenation process gas is subjected to polar impurity adsorption treatment to obtain carbon dioxide crude dehydration process gas. Based on the 3A molecular sieve adsorption tower, the carbon dioxide crude dehydration process gas is subjected to small molecule hydrocarbon adsorption treatment to obtain carbon dioxide adsorbed process gas.

7. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, characterized in that, The process of removing heavy components from the low-impurity carbon dioxide process gas by distillation to obtain refined carbon dioxide gas includes: Based on a pre-constructed precision filter, the low-impurity carbon dioxide process gas is filtered for solid and colloidal impurities to obtain carbon dioxide filtered process gas. Based on the pre-constructed dual purification tower, the carbon dioxide filtration process gas is subjected to distillation separation to obtain distilled gaseous phase and bottom liquid. Based on the liquid in the reactor, the gaseous phase after distillation is collected to obtain purified carbon dioxide gas.

8. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 7, characterized in that, The process of collecting the distilled gaseous phase based on the reactor liquid to obtain purified carbon dioxide gas includes: The liquid in the reactor is subjected to multi-index testing to obtain multi-index testing information of the liquid in the reactor, wherein the multi-index testing information of the liquid in the reactor includes information on whether the liquid in the reactor meets the standards or information on whether the liquid in the reactor does not meet the standards. Based on the multi-index compliance information of the reactor liquid, the gaseous phase after distillation is purified and collected to obtain refined carbon dioxide gas. Based on the information that the multiple indicators of the reactor liquid did not meet the standards, the reactor liquid was subjected to cyclic distillation and testing until the information of the multiple indicators of the reactor liquid met the standards, and gaseous matter was collected to obtain purified carbon dioxide gas.

9. The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, characterized in that, The cooling and liquefaction treatment of the refined carbon dioxide gas to obtain electronic-grade liquid carbon dioxide includes: The purity of the refined carbon dioxide gas was tested to obtain purity test data; Based on the purity test data, the condenser cooling liquefaction temperature parameters and condenser pressure parameters are determined. Based on the condenser cooling liquefaction temperature parameters and condenser pressure parameters, the refined carbon dioxide gas is subjected to gradient cooling liquefaction to obtain electronic-grade liquid carbon dioxide.

10. A carbon dioxide purification system based on temperature-switching adsorption, characterized in that, The carbon dioxide purification method based on temperature-switching adsorption as described in claim 1, wherein the system comprises: The preliminary impurity removal module is used to remove condensate impurities from the pre-acquired industrial-grade carbon dioxide feed gas to obtain pre-treated carbon dioxide feed gas. The gas desulfurization module is used to desulfurize the carbon dioxide pretreated raw gas to obtain carbon dioxide desulfurization process gas. The temperature-switching adsorption treatment module is used to perform temperature-switching adsorption treatment on the carbon dioxide desulfurization process gas to obtain low-impurity carbon dioxide process gas. The gas distillation and heavy removal module is used to distill and remove heavy components from the low-impurity carbon dioxide process gas to obtain refined carbon dioxide gas. The refined carbon dioxide gas is then cooled and liquefied to obtain electronic-grade liquid carbon dioxide.

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