13 CO Isotope Separation Tail Gas Purification Device and Method

Abstract

This invention relates to the field of gas purification technology, and specifically discloses a method that is easy to operate, has good purification effect, and produces purified gas with all indicators meeting electronic-grade application standards. 13 A CO isotope separation tail gas purification device includes, in sequence, a first diaphragm compressor, a dehydration tower, an adsorption tower, a light-weight gas removal tower, a dust collector, a first filter, a heavy-weight gas removal tower connected to the bottom of the light-weight gas removal tower, a second filter connected to the top of the heavy-weight gas removal tower, and a second diaphragm compressor connected to the second filter and outputting the purified CO product. A further disclosed... 13 A method for purifying CO isotope separation tail gas includes pressurizing and removing water from the CO tail gas to be purified, and adsorbing and removing gaseous impurities of a predetermined type from the tail gas; filtering the adsorbed tail gas for dust removal; distilling the filtered tail gas through a light gas removal tower and a heavy gas removal tower; filtering and compressing the distilled gas to obtain a purified CO product.

Description

Technical Field

[0001] This invention relates to the field of gas purification technology, and in particular to a... 13 CO isotope separation tail gas purification device and method. Background Technology

[0002] 13 CO gas is an important starting material for the synthesis of various carbon-13 labeled compounds, for example, in the synthesis of... 13 C-urea, then through 13 C-urea is used to prepare C-13 urea breath test kits for the diagnosis of Helicobacter pylori. Currently, low-temperature distillation is the main method used to produce them. 13 CO, specifically utilized 12 CO and 13 The difference in CO volatility enables 12 CO and 13 CO isotope separation, in 13 The production process of CO will generate a large amount of 12 CO exhaust gas, due to 12 CO is toxic and poses an environmental safety hazard, requiring treatment before release, which increases the risk of pollution. 13 The production cost of CO. Therefore, it is necessary to consider the production cost of CO. 13 The CO tail gas generated from CO isotope separation is recovered, for example, the recovered CO tail gas is recovered. 12 CO exhaust gas is used as an etching gas for semiconductor devices to create good economic benefits, reduce exhaust emissions and environmental pollution, and achieve resource recycling. However, when CO is used as a purging gas for semiconductor device etching, trace impurities in CO can cause defects in products with high-density integrated circuits. Therefore, high-purity CO used in large-scale integrated circuits requires a purity greater than 99.999%. 12 In the purification process of CO tail gas, it is necessary to remove impurities such as H2, CH4, O2, N2, CO2, H2O, Fe, and Ni metal ions from the tail gas.

[0003] Currently, CO purification methods mainly include distillation, adsorption, and membrane separation. Distillation is challenging due to the close boiling points of O2, N2, and CO. Furthermore, the similar molecular sizes of O2, N2, and CO make adsorption difficult to remove O2 and N2 impurities. During the transport and storage of high-purity gases, the use of steel pipelines and tanks leads to the continuous formation of impurities such as CO2, Fe, and Ni metal ions within the system. Limited by technological advancements, current membrane separation methods can only separate substances with significantly different molecular sizes from CO, such as H2, and cannot effectively separate CO from O2 and N2, resulting in significant purification difficulties and insufficient purification efficiency.

[0004] Furthermore, current CO gas purification mainly focuses on two aspects: one is the purification of syngas to produce high-purity hydrogen and high-purity CO, as described in Chinese invention patents ZL201610058980.X and ZL200610018674.X. However, in these methods, the CO gas is not derived from... 13 The components of the feed gas used in CO isotope separation tail gas and CO gas purification are also related to... 13 The components in the CO isotope separation tail gas are different, and the purity of the prepared CO gas does not reach the electronic grade standard of 99.999%. The second method is to prepare high-purity CO by cracking formic acid or sodium formate. The above methods are described in Chinese invention patents ZL201510593143.2, ZL201711293669.4, ZL201610779796.4, etc. However, the above methods mainly focus on the preparation process of CO raw materials, and the purity of the product depends on the source of raw materials. The gas purification effect is small, and the purity does not reach the standard of 99.999%. Summary of the Invention

[0005] Based on this, it is necessary to address 13 The purification of CO isotope separation exhaust gas is difficult and ineffective, resulting in gas purity that fails to meet electronic-grade application standards. This paper addresses the technical problem of providing an easy-to-operate method that achieves high purification efficiency, ensuring that all purified gas properties meet electronic-grade application standards. 13 CO isotope separation tail gas purification device and method.

[0006] A sort of 13 CO isotope separation tail gas purification device includes a first diaphragm compressor for receiving and compressing the CO tail gas to be purified, a dehydration tower connected to the output end of the first diaphragm compressor, an adsorption tower connected to the output end of the dehydration tower, a light-weight removal tower connected to the output end of the adsorption tower, a dust collector and a first filter installed on the connecting pipeline between the adsorption tower and the light-weight removal tower, a heavy-weight removal tower connected to the bottom of the light-weight removal tower, a second filter connected to the top of the heavy-weight removal tower, and a second diaphragm compressor connected to the output end of the second filter. The output end of the second diaphragm compressor outputs CO purified product.

[0007] 13 The CO isotope separation tail gas purification device also includes a first intermediate storage tank and a second intermediate storage tank. The first intermediate storage tank is installed on the connecting pipeline between the first diaphragm compressor and the dewatering tower, and is used to store the compression products of the first diaphragm compressor. The second intermediate storage tank is installed on the connecting pipeline between the second filter and the second diaphragm compressor, and is used to store the CO gas to be compressed and purified.

[0008] In one embodiment, the top of the light component removal tower is provided with a first pipeline, and a first condenser is provided on the first pipeline. The first condenser is connected to the inner cavity of the light component removal tower and the environment through the first pipeline. A light component discharge pipe for discharging light components is connected to the first condenser, and a first reflux pipe connected to the inner cavity of the light component removal tower is also provided at the bottom of the first condenser.

[0009] In one embodiment, the light-weight removal tower has a first liquid separator connected to the inner cavity of the light-weight removal tower near the bottom of the tower. The output end of the first liquid separator is connected to the connecting pipeline between the light-weight removal tower and the heavy-weight removal tower. A first reboiler is provided on the first liquid separator. The bottom of the heavy-weight removal tower has a heavy-weight removal pipeline. The tower body of the heavy-weight removal tower has a second liquid separator connected to the inner cavity of the heavy-weight removal tower near the bottom of the tower. The output end of the second liquid separator is connected to the heavy-weight removal pipeline. A second reboiler is provided on the second liquid separator.

[0010] In one embodiment, a second pipeline is provided at the top of the deweight removal tower, and a second condenser is provided on the second pipeline. The second condenser is connected to the inner cavity of the deweight removal tower through the second pipeline. A collection pipe is connected to the second condenser, and a second filter is provided on the collection pipe. A second reflux pipe connected to the inner cavity of the deweight removal tower is also provided at the bottom of the second condenser.

[0011] The present invention also discloses a 13 The CO isotope separation tail gas purification method includes the following steps:

[0012] S1: Pressurize the CO tail gas to be purified, and store it under pressure in the first intermediate storage tank. Remove water from the pressurized material and adsorb and remove the preset types of gaseous impurities in the tail gas.

[0013] S2: Dust removal and filtration of the adsorbed exhaust gas;

[0014] S3: The filtered tail gas is distilled through a light gas removal tower and a heavy gas removal tower;

[0015] In step S3, the filtered tail gas enters the middle of the light gas removal tower and undergoes a first distillation under the conditions of a bottom temperature of -180℃ to -150℃, a top temperature of -181℃ to -151℃, and a distillation pressure of 0.3MPa to 2.0MPa. The vapor phase from the first distillation is discharged through the top of the light gas removal tower. The tail gas flow rate entering the light gas removal tower is 3kg / h to 30kg / h, and the light gas discharge flow rate at the top of the light gas removal tower is 0.10kg / h to 2kg / h.

[0016] In step S3, a portion of the bottom liquid from the light-light removal tower is collected and enters the heavy-light removal tower. Secondary distillation is carried out under the conditions of a bottom temperature of -183℃ to -151℃, a top temperature of -184℃ to -152℃, and a distillation pressure of 0.2MPa to 1.9MPa. The distillation gas is condensed and output from the top of the heavy-light removal tower. The CO tail gas flow rate entering the heavy-light removal tower is 2.90kg / h to 28kg / h, the heavy-light removal flow rate at the bottom of the heavy-light removal tower is 0.10kg / h to 2kg / h, and the top collection rate of the heavy-light removal tower is 2.80kg / h to 26kg / h.

[0017] S4: Filter and compress the distillation gas, and store it under stable pressure in the second intermediate storage tank to obtain a purified CO product.

[0018] In one embodiment, in step S1, the CO tail gas to be purified is compressed using a diaphragm compressor and sequentially passed into a dehydration tower and an adsorption tower for dehydration and gas adsorption. The temperature of the CO tail gas to be purified is -20℃ to 30℃, the pressure of the diaphragm compressor is 1.5 to 3.0 MPa, the flow rate of the tail gas in the dehydration tower and adsorption tower is 3 kg / h to 30 kg / h, the adsorption pressure of the adsorption tower is 1.5 to 3.0 MPa, and the adsorption temperature is -80℃ to -10℃.

[0019] In one embodiment, condensers are respectively installed at the top of the light-weight removal tower and the top of the heavy-weight removal tower to condense the reflux liquid phase. The reflux ratio of the light-weight removal tower is 30 to 1500, and the reflux ratio of the heavy-weight removal tower is 3 to 50.

[0020] Implementing the present invention 13The CO isotope separation tail gas purification device and method sequentially connects a first diaphragm compressor, a dehydration tower, an adsorption tower, a light-weight gas removal tower, a dust collector, a first filter, a heavy-weight gas removal tower, a second filter, and a second diaphragm compressor. This allows for continuous tail gas purification operations including pressurization and dehydration, adsorption, filtration and dust removal, distillation, and filtration compression. This achieves continuous tail gas purification with low equipment investment, simple operation, high production capacity, high product yield, and good economic efficiency. After purification, the contents of O2 and N2, which have boiling points close to CO, are reduced to below 1 ppm, yielding a CO purified product with a purity greater than 99.999%. The combination of adsorption and distillation methods further reduces the content of H2O and CO2 impurities. All impurities are reduced to below 1 ppm, with methane and hydrogen reduced to below 0.5 ppm. Combining a dehydration tower and distillation can reduce iron and nickel metal ions to below 10 ppb. A light component removal tower is used to remove light components, and a heavy component removal tower is used to remove heavy components, thereby reducing the content of light and heavy component impurities in the distillation system. A dehydration tower and an adsorption tower are used to adsorb some impurity compounds, reducing the amount of light components removed and the amount of heavy components removed during continuous distillation, improving product yield, production capacity, and product quality. By controlling the distillation and adsorption parameters, the total impurity content can be reduced to less than 10 ppm, greatly improving the purity of CO. The high-purity CO product produced has stable quality and is suitable for large-scale continuous industrial production. Attached Figure Description

[0021] Figure 1 In one embodiment of the present invention 13 Schematic diagram of a CO isotope separation tail gas purification device;

[0022] Figure 2 In one embodiment of the present invention 13 Flowchart of CO isotope separation tail gas purification method. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] When high-purity CO is used in the purging and etching processes of semiconductor devices, the purity of the CO gas is critical to prevent damage to the semiconductor devices from trace impurities. Currently, the technical specifications for ultra-high purity CO used in semiconductors are shown in the table below:

[0025] Table 1 Technical Specifications of Electronic Grade High-Purity CO

[0026] carbon monoxide ≥99.999％ hydrogen ≤0.5ppm Nitrogen ≤4ppm oxygen ≤1ppm carbon dioxide ≤3ppm water ≤1ppm methane ≤0.5ppm iron ≤0.1ppm nickel ≤0.1ppm

[0027] 13 The main impurities in the CO isotope separation tail gas are H2, CH4, O2, N2, CO2, H2O, Fe, Ni metal ions, etc., with some concentrations as low as 1×10⁻⁶. -6 Even 1×10 -9 In order to obtain high-purity CO at the volume ratio (i.e., ppm or ppb) level, further purification is required to remove the above-mentioned impurities.

[0028] Among them, the boiling points of O2, N2 and CO are close, and the boiling point data of the three are shown in the table below:

[0029] Table 2 Boiling Point Indices for O2, N2, and CO

[0030] oxygen <![CDATA[O2]]> -183 Nitrogen <![CDATA[N2]]> -195.8 carbon monoxide CO -191.5

[0031] Because the boiling points of O2 and N2 are close to those of CO, distillation is difficult. At the same time, because the molecular sizes of oxygen, nitrogen, and CO are similar, it is difficult to remove oxygen and nitrogen impurities by adsorption. In the process of transporting and storing high-purity gases, due to the use of steel pipelines and storage tanks, impurities such as CO2, Fe, and Ni metal ions will continuously form in the system. These are the key challenges in the production of high-purity CO.

[0032] Based on this, the present invention provides a continuous purification method that combines multiple purification techniques. 13 The CO isotope separation tail gas purification device 10 is easy to operate, has good purification effect, and the purified gas meets all electronic grade application standards, enabling large-scale application of tail gas purification. For details, please refer to [link / reference]. Figure 1 In this embodiment 13 The CO isotope separation tail gas purification device 10 includes a first diaphragm compressor 101 for receiving and compressing the CO tail gas to be purified, a dehydration tower 102 connected to the output end of the first diaphragm compressor 101, an adsorption tower 103 connected to the output end of the dehydration tower 102, a light-weight removal tower 104 connected to the output end of the adsorption tower 103, a dust collector 105 and a first filter 106 installed on the connecting pipeline between the adsorption tower 103 and the light-weight removal tower 104, a heavy-weight removal tower 107 connected to the bottom of the light-weight removal tower 104, a second filter 108 connected to the top of the heavy-weight removal tower 107, and a second diaphragm compressor 109 connected to the output end of the second filter 108. The output end of the second diaphragm compressor 109 outputs the purified CO product. In this embodiment, water-absorbing resin particles, CaCl2, CaSO4, and other commonly available desiccants can be added to the dehydration tower 102. The adsorption tower 103 is equipped with a desiccant and a carbon dioxide adsorbent to remove H2O and CO2 from the tail gas.

[0033] Furthermore,13 The CO isotope separation tail gas purification device 10 also includes a first intermediate storage tank 110 and a second intermediate storage tank 111. The first intermediate storage tank 110 is located on the connecting pipeline between the first diaphragm compressor 101 and the dewatering tower 102, and is used to store the compression products of the first diaphragm compressor 101. The second intermediate storage tank 111 is located on the connecting pipeline between the second filter 108 and the second diaphragm compressor 109, and is used to store the CO gas to be compressed for purification. The first intermediate storage tank 110 serves as a temporary storage or buffer container for the CO compression tail gas and is used to stabilize the pressure of the CO compression tail gas. The second intermediate storage tank 111 serves as a storage container for the final CO product and is used to stabilize the pressure of the final CO product. After purification, the CO gas in the second intermediate storage tank 111 can be directly taken out, or the CO gas in the second intermediate storage tank 111 can be further passed into the second diaphragm compressor 109 for compression, compressing the gas into a packaging container such as a steel cylinder for transportation and storage of the CO gas.

[0034] exist 13 During the use of the CO isotope separation tail gas purification device 10, the tail gas to be purified is introduced into the first diaphragm compressor 101 through the input end of the first diaphragm compressor 101. Through the compression action of the first diaphragm compressor 101, the compressed tail gas passes through the dehydration tower 102 to remove H2O. In this embodiment, the first diaphragm compressor 101 is used to pressurize the CO tail gas to be purified, and a storage tank can also be provided to store the pressurized tail gas. After the tail gas enters the adsorption tower 103, the H2O and CO2 in the mixed gas are adsorbed by the adsorbent in the adsorption tower 103, thereby removing CO2 and further removing H2O from the tail gas. After removing H2O and CO2, the exhaust gas is filtered and then passed through a light component removal tower 104 to remove low-boiling-point light component impurities such as N2 and H2. Subsequently, under the action of a heavy component removal tower 107, CO is separated from heavy component impurities such as O2 and CH4. The CO is then output from the top of the heavy component removal tower 107, filtered by a second filter 108, and compressed by a second diaphragm compressor 109 to obtain a high-purity CO product. This embodiment... 13 The CO isotope separation tail gas purification device 10 is a continuous structure. After the CO tail gas to be purified enters the first diaphragm compressor 101, it is sequentially introduced into each device, where separation operations are performed, and finally discharged from the device. 13 The output of the CO isotope separation tail gas purification device 10, namely the end of the second diaphragm compressor 109, outputs high-purity CO products, enabling large-scale continuous purification of tail gas and reducing the difficulty of tail gas purification. Furthermore, by combining adsorption and distillation, and combining the dewatering tower 102 with distillation, various impurity indicators in the tail gas can be reduced to below the CO electronic grade application standard, meeting the requirements for the industrial application of CO gas.

[0035] In one embodiment, the dehydration tower 102 has a first feed inlet at its bottom that communicates with the first diaphragm compressor 101, and a first discharge outlet at its top; the adsorption tower 103 has a second feed inlet at its bottom that communicates with the first discharge outlet, and a second discharge outlet at its top. Thus, when the exhaust gas enters the dehydration tower 102 and the adsorption tower 103, it flows to the next device to remove H2O and CO2 from the exhaust gas.

[0036] Furthermore, in this embodiment, the feed inlet of the light-weight removal tower 104 is located in the middle of the light-weight removal tower 104, and the feed inlet of the heavy-weight removal tower 107 is located in the middle of the heavy-weight removal tower 107. Thus, after the light-weight removal tower 104 and the heavy-weight removal tower 107 are introduced, the tail gas is separated under a preset distillation pressure. The pre-distilled product is output in gaseous form from the top of the light-weight removal tower 104 or the heavy-weight removal tower 107, and the remaining material is output from the bottom of the light-weight removal tower 104 or the heavy-weight removal tower 107 to the next device or to an external device for unified processing.

[0037] Please refer to it again. Figure 1 The light component removal tower 104 has a first pipeline 1041 at its top, and a first condenser 1042 on the first pipeline. The first condenser 1042 is connected to the inner cavity of the light component removal tower 104 and the environment through the first pipeline. A light component discharge pipe is connected to the first condenser 1042 for discharging light components. The bottom of the first condenser 1042 is also provided with a first reflux pipe 1043 connected to the inner cavity of the light component removal tower 104 to reflux liquefied CO back into the light component removal tower 104. Near the bottom of the light component removal tower 104, a first liquid separator 1044 connected to the inner cavity of the light component removal tower 104 is provided on the tower body. The output end of the first liquid separator 1044 is connected to the connecting pipeline between the light component removal tower 104 and the heavy component removal tower 107. A first reboiler 1045 is provided on the first liquid separator 1044 to provide the heat required for distillation of the material in the light component removal tower 104. The bottom of the deweight removal column 107 is equipped with a deweight removal pipeline 1071. A second liquid separator 1072, communicating with the inner cavity of the deweight removal column 107, is located near the bottom of the column. The output end of the second liquid separator 1072 is connected to the deweight removal pipeline 1071, and a second reboiler 1073 is installed on the second liquid separator 1072. The second reboiler 1073 provides the heat required for distillation to the material inside the deweight removal column 107.

[0038] Furthermore, a second pipeline is provided at the top of the heavy-weight removal tower 107, and a second condenser 1075 is installed on the second pipeline. The second condenser 1075 is connected to the inner cavity of the heavy-weight removal tower 107 through the second pipeline. A collection pipe 1074 is connected to the second condenser 1075, and a second filter is installed on the collection pipe 1074. A second reflux pipe 1076, which is connected to the inner cavity of the heavy-weight removal tower 107, is also provided at the bottom of the second condenser 1075. By setting the second reflux pipe 1076, the liquefied CO is returned to the light-weight removal tower 104.

[0039] It should be noted that in this embodiment, the first condenser 1042 and the first reboiler 1045 can be an integral structure or connected by a pipeline, so that the gas treated by the first reboiler 1045 is condensed at the first condenser 1042 and returned to the light-weight gas removal tower 104. Similarly, the second condenser 1075 and the second reboiler 1073 can be an integral structure or connected by a pipeline, so that the gas treated by the second reboiler 1073 is condensed at the second condenser 1075 and returned to the heavy-weight gas removal tower 107. Furthermore, in this embodiment, both the first condenser 1042 and the second condenser 1075 are partial condensers, with part of the gas condensed and returned, and part discharged through the top pipeline of the tower.

[0040] Furthermore, in this embodiment, the reflux ratio of the light-weight removal tower 104 is 30–1500, and the reflux ratio of the heavy-weight removal tower 107 is 3–50. Liquid nitrogen is used as a cold source at the top of both the light-weight removal tower 104 and the heavy-weight removal tower 107; that is, liquid nitrogen is used as a cold source in the first condenser 1042 and the second condenser 1075. The cold nitrogen gas at the outlets of the first condenser 1042 and the second condenser 1075 is connected to the adsorption tower 103 to provide a cold source for the adsorption tower 103, thus achieving full utilization of the cooling capacity and saving more than 10% of liquid nitrogen. The light-weight removal tower 104 and the heavy-weight removal tower 107 are packed distillation towers with different distillation pressures. The packing material in the light-weight removal tower 104 and the heavy-weight removal tower 107 can be θ-rings, triangular spirals, or rolled perforated plates. The packing material is stainless steel, and the packing diameter is 2 mm–30 mm, preferably 2 mm–10 mm. Furthermore, the light-weight removal tower 104 and the heavy-weight removal tower 107 are made of stainless steel. The height of the light-weight removal tower 104 and the heavy-weight removal tower 107 is 2m to 15m, preferably 5m to 12m; the diameter is 50mm to 200mm, preferably 100mm to 150mm; the diameter of the water removal tower 102 and the adsorption tower 103 is 50mm to 300mm, and the height is 0.5m to 3m; the filtration accuracy of the first filter 106 and the second filter 108 is 0.003 micrometers to 0.5 micrometers.

[0041] In one embodiment, 13 The working process of CO isotope separation tail gas purification device 10 is as follows:

[0042] Recycling of the material to be purified 13The CO isotope separation tail gas is compressed by the first diaphragm compressor 101 into the first intermediate storage tank 110 at a pressure of 1.5–3.0 MPa, and then enters the dehydration tower 102 at a flow rate of 3 kg / h–30 kg / h. It then enters the adsorption tower 103 for adsorption at an adsorption pressure of 1.5–3.0 MPa and a temperature of -80℃–-10℃. The adsorbed CO passes through the dust collector 105 and the first filter 106, and then enters the middle of the light component removal tower 104 at a flow rate of 3 kg / h–30 kg / h. It undergoes a single distillation under conditions of a bottom temperature of -180℃–-150℃, a top temperature of -181℃–-151℃, and a distillation pressure of 0.3 MPa–2.0 MPa. The gaseous portion is discharged through the light component discharge pipe at the top of the tower at a flow rate of 0.10 kg / h–2 kg / h. Part of the liquid from the bottom of the light-light product removal column 104 enters the first reboiler 1045 at the bottom of the light-light product removal column 104, while part of it, through the bottom outlet, enters the heavy-weight product removal column 107 at a flow rate of 2.9 kg / h to 28 kg / h for secondary distillation. The bottom temperature of the heavy-weight product removal column 107 is -183℃ to -151℃, the top temperature is -184℃ to -152℃, and the distillation pressure is 0.2 MPa to 1.9 MPa. The vapor phase from the top of the heavy-weight product removal column 107 is collected and enters the second condenser 10 at the top of the heavy-weight product removal column 107. 75. The top condenser of the heavy removal tower 107 is a partial condenser. After condensation, the liquid phase is refluxed, and the gas phase, as electronic grade CO product, is collected after passing through the second filter 108 and enters the second intermediate storage tank 111 at a flow rate of 2.8 kg / h to 26 kg / h. After being compressed by the second diaphragm compressor 109, high-purity CO bottled product is obtained. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part of it is collected as heavy component impurities. The bottom discharge flow rate is 0.10 kg / h to 2 kg / h.

[0043] Please see Figure 2 The present invention also discloses a 13 CO isotope separation tail gas purification method 20, this method adopts the aforementioned 13 The CO isotope separation tail gas purification device 10 performs separation and purification operations, including the following steps:

[0044] S1: Pressurize the purified CO tail gas and store it under pressure in the first intermediate storage tank 110. Remove water from the pressurized material and adsorb and remove the preset types of gaseous impurities in the tail gas.

[0045] In step S1, the CO tail gas to be purified is compressed using a diaphragm compressor and sequentially introduced into the dehydration tower 102 and the adsorption tower 103 for dehydration and gas adsorption. The temperature of the CO tail gas to be purified is -20℃ to 30℃, the pressure of the diaphragm compressor is 1.5 to 3.0 MPa, the flow rate of the tail gas in the dehydration tower 102 and the adsorption tower 103 is 3 kg / h to 30 kg / h, the adsorption pressure of the adsorption tower 103 is 1.5 to 3.0 MPa, and the adsorption temperature is -80℃ to -10℃.

[0046] S2: Dust removal and filtration of the adsorbed exhaust gas.

[0047] In step S2, the exhaust gas output from the adsorption tower 103 is sequentially passed into the dust collector 105 and the first filter 106 to remove solid particulate impurities from the exhaust gas.

[0048] S3: The filtered tail gas is distilled through light gas removal tower 104 and heavy gas removal tower 107.

[0049] In step S3, the filtered tail gas enters the middle of the light gas removal tower 104 and undergoes a first distillation under the conditions of a bottom temperature of -180℃ to -150℃, a top temperature of -181℃ to -151℃, and a distillation pressure of 0.3MPa to 2.0MPa. The gas phase from the first distillation is discharged through the top of the light gas removal tower 104. The tail gas flow rate entering the light gas removal tower 104 is 3kg / h to 30kg / h, and the light gas discharge flow rate at the top of the light gas removal tower 104 is 0.10kg / h to 2kg / h. Part of the liquid from the bottom of the light component removal tower 104 enters the heavy component removal tower 107. Secondary distillation is carried out under the conditions of a bottom temperature of -183℃ to -151℃, a top temperature of -184℃ to -152℃, and a distillation pressure of 0.2MPa to 1.9MPa. The distillation gas is condensed and output from the top of the heavy component removal tower 107. The tail gas flow rate entering the heavy component removal tower 107 is 2.90 kg / h to 28 kg / h, the heavy component removal flow rate at the bottom of the heavy component removal tower 107 is 0.10 kg / h to 2 kg / h, and the top product rate of the heavy component removal tower 107 is 2.80 kg / h to 26 kg / h.

[0050] In this embodiment, only a portion of the bottom liquid from the light-weight removal tower 104 is collected and fed into the heavy-weight removal tower 107 for secondary distillation. The remaining portion of the bottom liquid from the light-weight removal tower 104 (i.e., the upper layer of the bottom liquid from the light-weight removal tower 104) is fed into the first reboiler 1045 through the first separator 1044 at the bottom of the light-weight removal tower 104 for reboiling, providing the heat required for distillation to the material inside the light-weight removal tower 104. Similarly, only a portion of the bottom liquid from the heavy-weight removal tower 107 is collected and processed. The remaining portion of the bottom liquid from the heavy-weight removal tower 107 (i.e., the upper layer of the bottom liquid from the heavy-weight removal tower 107) is fed into the second reboiler 1073 through the second separator 1072 at the bottom of the heavy-weight removal tower 107 for reboiling, providing the heat required for distillation to the material inside the heavy-weight removal tower 107.

[0051] Furthermore, in step S3, condensers are respectively installed at the top of the light-weight removal tower 104 and the top of the heavy-weight removal tower 107 to condense the reflux liquid phase. The reflux ratio of the light-weight removal tower 104 is 30–1500, and the reflux ratio of the heavy-weight removal tower 107 is 3–50. Specifically, a first condenser 1042 is installed at the top of the light-weight removal tower 104, and a second condenser 1075 is installed at the top of the heavy-weight removal tower 107. The first condenser 1042 is used to condense the gas at the top of the light-weight removal tower 104, and the second condenser 1075 is used to condense the gas at the top of the heavy-weight removal tower 107, liquefying the gas and refluxing it back into the distillation column. Liquid nitrogen is used as a cold source for the first condenser 1042 and the second condenser 1075, and the cold nitrogen gas from the outlets of the first condenser 1042 and the second condenser 1075 provides a cold source for the adsorption tower 103, achieving full utilization of the cooling capacity and saving more than 10% of liquid nitrogen.

[0052] In this embodiment, a light component removal tower 104 is used to remove light components, and a heavy component removal tower 107 is used to remove heavy components, thereby reducing the content of light and heavy component impurities in the distillation system. A dehydration tower 102 and an adsorption tower 103 are used to adsorb some impurity compounds, reducing the amount of light and heavy components removed during continuous distillation, improving product yield, operational safety, production capacity, and product quality. By combining the primary distillation of the dehydration tower 102 and the light component removal tower 104 with the secondary distillation of the heavy component removal tower 107, iron and nickel metal ions can be reduced to below 10 ppb. Combining the primary distillation of the adsorption tower 103 with the light component removal tower 104 and the secondary distillation of the heavy component removal tower 107 reduces the content of H2O and CO2 impurities to below 1 ppm, and methane and hydrogen to below 0.5 ppm.

[0053] S4: Filter and compress the distillation gas, and store it under stable pressure in the second intermediate storage tank 111 to obtain the CO purified product.

[0054] The following specific examples illustrate the separation and purification using the apparatus and method of the present invention. 13 The effect of CO isotope separation of tail gas was evaluated. The composition and content of the gas before and after purification were detected by gas chromatography with PDHID detector, and metal ions were detected by ICP-MS.

[0055] Example 1

[0056] The raw material gas has the following composition:

[0057] Table 3. Raw material gas phase composition of Example 1

[0058]

[0059] 13The parameters of the CO isotope separation tail gas purification device 10 are as follows: the water removal tower 102 and adsorption tower 103 have a diameter of 50 mm and a height of 0.5 m. The light-weight removal tower 104 and heavy-weight removal tower 107 are stainless steel distillation towers, packed with stainless steel θ-rings with a diameter of 2 mm. The distillation towers are 2 m high and 50 mm in diameter. The filtration accuracy of the first filter 106 and the second filter 108 is 0.003 microns.

[0060] The operation method is as follows:

[0061] The crude tail gas at -20℃ is compressed into the first intermediate storage tank 110 at a flow rate of 3 kg / h using the first diaphragm compressor 101. The pressure is 1.5 MPa. The gas then enters the dewatering tower 102 at a flow rate of 3 kg / h, and then enters the adsorption tower 103 for adsorption. The adsorption pressure is 1.5 MPa and the temperature is -80℃.

[0062] After adsorption, the CO passes through dust collector 105 and first filter 106, and then enters the middle of light-weight component removal tower 104 at a flow rate of 3 kg / h. Distillation is carried out under the conditions of bottom temperature of -180℃, top temperature of -181℃, and distillation pressure of 0.3 MPa. The gas phase is discharged through the light-weight component discharge outlet at the top of the tower at a flow rate of 0.40 kg / h and a reflux ratio of 30.

[0063] Part of the liquid from the bottom of the light component removal column 104 enters the first reboiler 1045 at the bottom of the light component removal column 104, while part of it passes through the bottom outlet and enters the feed inlet of the heavy component removal column 107 at a flow rate of 2.6 kg / h for rectification. The bottom temperature of the heavy component removal column 107 is -183℃, the top temperature is -184℃, and the rectification pressure is 0.2 MPa. The vapor phase from the top of the heavy component removal column 107 is collected and enters the second condenser 1075 at the top of the heavy component removal column 107. Condenser 1075 is a partial condenser. After condensation in the second condenser 1075, the liquid phase is refluxed, and the gas phase, as electronic-grade CO product, is collected after passing through the second filter at a flow rate of 2.5 kg / h and enters the second intermediate storage tank 111. After being compressed by the second diaphragm compressor 109, high-purity CO bottled product is obtained. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part is collected as heavy component impurities. The bottom discharge flow rate is 0.10 kg / h, and the reflux ratio is 3.

[0064] The impurity content in the purified CO gas was detected using analytical instruments. Table 4 shows the impurity content in the purified CO obtained in Example 1 of this invention. The purity of the purified high-purity CO was calculated to be 99.9999%.

[0065] Table 4 Gas parameters after purification in Example 1

[0066]

[0067] The cold nitrogen gas from the condenser outlets of the light removal tower 104 and the heavy removal tower 107 provides a cold source for the adsorption tower, and liquid nitrogen is also used to provide a cold source for the adsorption tower, reducing the total liquid nitrogen consumption during purification by 15%.

[0068] Example 2

[0069] The raw material gas has the following composition:

[0070] Table 5. Gas phase composition of raw materials in Example 2

[0071]

[0072] 13 The parameters of the CO isotope separation tail gas purification device 10 are as follows: the dewatering tower 102 and the adsorption tower 103 have a diameter of 300 mm and a height of 3 m. The light-weight removal tower 104 and the heavy-weight removal tower 107 are stainless steel distillation towers, packed with stainless steel rolled perforated plate packing with a diameter of 30 mm. The distillation towers have a height of 15 m and a diameter of 200 mm. The filtration accuracy of the first filter 106 and the second filter 108 is 0.5 microns.

[0073] The operation method is as follows:

[0074] The crude tail gas at 30℃ is compressed into the first intermediate storage tank 110 at a flow rate of 30 kg / h using the first diaphragm compressor 101. The pressure is 2.0 MPa. The crude gas then enters the dewatering tower 102 at a flow rate of 30 kg / h, and then enters the adsorption tower 103 for adsorption. The adsorption pressure is 2.0 MPa and the temperature is -10℃.

[0075] After adsorption, the CO passes through dust collector 105 and first filter 106, and then enters the middle of light component removal tower 104 at a flow rate of 30 kg / h. Distillation is carried out under the conditions of bottom temperature of -163℃, top temperature of -164℃, and distillation pressure of 1.0 MPa. The gas phase is discharged through the light component discharge outlet at the top of the tower at a flow rate of 2.0 kg / h and a reflux ratio of 200.

[0076] Part of the liquid from the bottom of the light component removal column 104 enters the first reboiler 1045 at the bottom of the light component removal column 104, while part of it passes through the bottom outlet and enters the feed inlet of the heavy component removal column 107 at a flow rate of 28 kg / h for rectification. The bottom temperature of the heavy component removal column 107 is -166℃, the top temperature is -167℃, and the rectification pressure is 0.8 MPa. The vapor phase from the top of the heavy component removal column 107 is collected and enters the second condenser 1075 at the top of the heavy component removal column 107. Condenser 1075 is a partial condenser. After condensation in the second condenser 1075, the liquid phase is refluxed, and the gas phase is collected as electronic-grade CO product after passing through the second filter at a flow rate of 26 kg / h. It enters the second intermediate storage tank 111 and is compressed by the second diaphragm compressor 109 to obtain high-purity CO bottled product. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part of it is collected as heavy component impurities. The bottom discharge flow rate is 2.0 kg / h, and the reflux ratio is 15.

[0077] The impurity content in the purified CO gas was detected using analytical instruments. Table 6 shows the impurity content in the purified CO obtained in Example 2 of this invention. The purity of the purified high-purity CO was calculated to be 99.9999%.

[0078] Table 6 Gas parameters after purification in Example 2

[0079]

[0080] The cold nitrogen gas from the condenser outlets of the light removal tower 104 and the heavy removal tower 107 provides a cold source for the adsorption tower, and liquid nitrogen is also used to provide a cold source for the adsorption tower, reducing the total liquid nitrogen consumption during purification by 10%.

[0081] Example 3

[0082] The raw material gas has the following composition:

[0083] Table 7. Gas phase composition of raw materials in Example 3

[0084]

[0085] 13 The parameters of the CO isotope separation tail gas purification device 10 are as follows: the dewatering tower 102 and the adsorption tower 103 have a diameter of 200 mm and a height of 2 m. The light-weight removal tower 104 and the heavy-weight removal tower 107 are stainless steel distillation towers, packed with stainless steel triangular spiral packing with a diameter of 10 mm. The distillation towers are 12 m high and 150 mm in diameter. The filtration accuracy of the first filter 106 and the second filter 108 is 0.006 microns.

[0086] The operation method is as follows:

[0087] The crude tail gas at 10℃ is compressed into the first intermediate storage tank 110 at a flow rate of 10 kg / h using the first diaphragm compressor 101. The pressure is 3.0 MPa. The crude gas then enters the dewatering tower 102 at a flow rate of 10 kg / h, and then enters the adsorption tower 103 for adsorption. The adsorption pressure is 3.0 MPa and the temperature is -30℃.

[0088] After adsorption, the CO passes through dust collector 105 and first filter 106, and then enters the middle of light component removal tower 104 at a flow rate of 10 kg / h. Distillation is carried out under the conditions of bottom temperature of -150℃, top temperature of -151℃, and distillation pressure of 2.0 MPa. The gas phase is discharged through the light component discharge outlet at the top of the tower at a flow rate of 0.2 kg / h and a reflux ratio of 1500.

[0089] Part of the liquid from the bottom of the light component removal column 104 enters the first reboiler 1045 at the bottom of the light component removal column 104, while part of it passes through the bottom outlet and enters the feed inlet of the heavy component removal column 107 at a flow rate of 9.8 kg / h for rectification. The bottom temperature of the heavy component removal column 107 is -151℃, the top temperature is -152℃, and the rectification pressure is 1.9 MPa. The vapor phase from the top of the heavy component removal column 107 is collected and enters the second condenser 1075 at the top of the heavy component removal column 107. Condenser 1075 is a partial condenser. After condensation in the second condenser 1075, the liquid phase is refluxed, and the gas phase, as electronic-grade CO product, is collected after passing through the second filter at a flow rate of 9.6 kg / h and enters the second intermediate storage tank 111. After being compressed by the second diaphragm compressor 109, high-purity CO bottled product is obtained. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part is collected as heavy component impurities. The bottom discharge flow rate is 0.2 kg / h, and the reflux ratio is 30.

[0090] The impurity content in the purified CO gas was detected using analytical instruments. Table 8 shows the impurity content in the purified CO obtained in Example 3 of this invention. The purity of the purified high-purity CO was calculated to be 99.9999%.

[0091] Table 8 Gas parameters after purification in Example 3

[0092]

[0093] The cold nitrogen gas from the condenser outlets of the light removal tower 104 and the heavy removal tower 107 provides a cold source for the adsorption tower, and liquid nitrogen is also used to provide a cold source for the adsorption tower, reducing the total liquid nitrogen consumption during purification by 10%.

[0094] Example 4

[0095] The raw material gas has the following composition:

[0096] Table 9. Gas phase composition of raw materials in Example 4

[0097]

[0098] 13 The parameters of the CO isotope separation tail gas purification device 10 are as follows: the dewatering tower 102 and adsorption tower 103 have a diameter of 200 mm and a height of 2 m. The light-weight removal tower 104 and heavy-weight removal tower 107 are stainless steel distillation towers, packed with 6 mm diameter stainless steel rolled perforated plate packing, with a height of 5 m and a diameter of 100 mm. The filtration accuracy of the first filter 106 and the second filter 108 is 0.003 microns.

[0099] The operation method is as follows:

[0100] The crude tail gas at 20℃ is compressed into the first intermediate storage tank 110 at a flow rate of 10 kg / h using the first diaphragm compressor 101. The pressure is 2.0 MPa. The crude gas then enters the dewatering tower 102 at a flow rate of 10 kg / h, and then enters the adsorption tower 103 for adsorption. The adsorption pressure is 2.0 MPa and the temperature is -20℃.

[0101] After adsorption, the CO passes through dust collector 105 and first filter 106, and then enters the middle of light component removal tower 104 at a flow rate of 10 kg / h. Distillation is carried out under the conditions of bottom temperature of -163℃, top temperature of -164℃, and distillation pressure of 1.0 MPa. The gas phase is discharged through the light component discharge outlet at the top of the tower at a flow rate of 0.2 kg / h and a reflux ratio of 500.

[0102] Part of the liquid from the bottom of the light component removal column 104 enters the first reboiler 1045 at the bottom of the light component removal column 104, while part of it passes through the bottom outlet and enters the feed inlet of the heavy component removal column 107 at a flow rate of 9.8 kg / h for rectification. The bottom temperature of the heavy component removal column 107 is -166℃, the top temperature is -167℃, and the rectification pressure is 0.8 MPa. The vapor phase from the top of the heavy component removal column 107 is collected and enters the second condenser 1075 at the top of the heavy component removal column 107. Condenser 1075 is a partial condenser. After condensation in the second condenser 1075, the liquid phase is refluxed, and the gas phase, as electronic-grade CO product, is collected after passing through the second filter at a flow rate of 9.6 kg / h and enters the second intermediate storage tank 111. After being compressed by the second diaphragm compressor 109, high-purity CO bottled product is obtained. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part is collected as heavy component impurities. The bottom discharge flow rate is 0.2 kg / h, and the reflux ratio is 10.

[0103] The impurity content in the purified CO gas was detected using analytical instruments. Table 10 shows the impurity content in the purified CO obtained in Example 4 of this invention. The purity of the purified high-purity CO was calculated to be 99.9999%.

[0104] Table 10 Gas parameters after purification in Example 4

[0105]

[0106] The cold nitrogen gas from the condenser outlets of the light removal tower 104 and the heavy removal tower 107 provides a cold source for the adsorption tower, and liquid nitrogen is also used to provide a cold source for the adsorption tower, reducing the total liquid nitrogen consumption during purification by 10%.

[0107] Example 5

[0108] The raw material gas has the following composition:

[0109] Table 11. Gas phase composition of raw materials in Example 5

[0110]

[0111] 13 The parameters of the CO isotope separation tail gas purification device 10 are as follows: the dewatering tower 102 and adsorption tower 103 have a diameter of 200 mm and a height of 2 m. The light-weight removal tower 104 and heavy-weight removal tower 107 are stainless steel distillation towers, packed with 6 mm diameter stainless steel rolled perforated plate packing, with a tower height of 10 m and a diameter of 120 mm. The filtration accuracy of the first filter 106 and the second filter 108 is 0.003 microns.

[0112] The operation method is as follows:

[0113] The crude tail gas at 20℃ is compressed into the first intermediate storage tank 110 at a flow rate of 3 kg / h using the first diaphragm compressor 101. The pressure is 2.0 MPa. The crude gas then enters the dewatering tower 102 at a flow rate of 3 kg / h, and then enters the adsorption tower 103 for adsorption. The adsorption pressure is 2.0 MPa and the temperature is -20℃.

[0114] After adsorption, the CO passes through dust collector 105 and first filter 106, and then enters the middle of light component removal tower 104 at a flow rate of 3 kg / h. Distillation is carried out under the conditions of bottom temperature of -163℃, top temperature of -164℃, and distillation pressure of 1.0 MPa. The gas phase is discharged through the light component discharge outlet at the top of the tower at a flow rate of 0.1 kg / h and a reflux ratio of 1200.

[0115] Part of the liquid from the bottom of the light component removal column 104 enters the first reboiler 1045 at the bottom of the light component removal column 104, while part of it passes through the bottom outlet and enters the feed inlet of the heavy component removal column 107 at a flow rate of 2.9 kg / h for rectification. The bottom temperature of the heavy component removal column 107 is -166℃, the top temperature is -167℃, and the rectification pressure is 0.8 MPa. The vapor phase from the top of the heavy component removal column 107 is collected and enters the second condenser 1075 at the top of the heavy component removal column 107. Condenser 1075 is a partial condenser. After condensation in the second condenser 1075, the liquid phase is refluxed, and the gas phase, as electronic-grade CO product, is collected after passing through the second filter at a flow rate of 2.8 kg / h and enters the second intermediate storage tank 111. After being compressed by the second diaphragm compressor 109, high-purity CO bottled product is obtained. Part of the liquid from the bottom of the heavy removal tower 107 enters the second reboiler 1073 at the bottom of the heavy removal tower 107, and part of it is collected as heavy component impurities. The bottom discharge flow rate is 0.1 kg / h, and the reflux ratio is 50.

[0116] The impurity content in the purified CO gas was detected using analytical instruments. Table 12 shows the impurity content in the purified CO obtained in Example 5 of this invention. The purity of the purified high-purity CO was calculated to be 99.9999%.

[0117] Table 12 Gas parameters after purification in Example 5

[0118]

[0119] The cold nitrogen gas from the condenser outlets of the light removal tower 104 and the heavy removal tower 107 provides a cold source for the adsorption tower, and liquid nitrogen is also used to provide a cold source for the adsorption tower, reducing the total liquid nitrogen consumption during the purification process by 12%.

[0120] Implementing the present invention 13The CO isotope separation tail gas purification device 10 and method sequentially connect a first diaphragm compressor 101, a dehydration tower 102, an adsorption tower 103, a light-weight gas removal tower 104, a dust collector 105, a first filter 106, a heavy-weight gas removal tower 107, a second filter 108, and a second diaphragm compressor 109. This allows for continuous tail gas purification operations including pressurization and dehydration, adsorption, filtration and dust removal, distillation, and filtration compression. This achieves continuous tail gas purification with low equipment investment, simple operation, high production capacity, high product yield, and good economic efficiency. After purification, the contents of O2 and N2, which have boiling points close to CO, are reduced to below 1 ppm, yielding a CO purified product with a purity greater than 99.999%. The combination of adsorption and distillation methods further enhances the purification of H2O, ... The CO2 impurity content is reduced to below 1 ppm, and methane and hydrogen to below 0.5 ppm. Combining the dehydration tower 102 with distillation can reduce iron and nickel metal ions to below 10 ppb. The light component removal tower 104 is used to remove light components, and the heavy component removal tower 107 is used to remove heavy components, thereby reducing the content of light and heavy component impurities in the distillation system. The dehydration tower 102 and adsorption tower 103 adsorb some impurity compounds, reducing the amount of light components removed and the amount of heavy components removed in the continuous distillation process, improving product yield, production capacity and product quality. By controlling the distillation and adsorption parameters, the total impurity content can be reduced to less than 10 ppm, which greatly improves the purity of CO. The high-purity CO product produced has stable quality and is suitable for large-scale continuous industrial production.

[0121] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A kind 13 The CO isotope separation tail gas purification device is characterized by... It includes a first diaphragm compressor for receiving and compressing the CO tail gas to be purified, a dehydration tower connected to the output end of the first diaphragm compressor, an adsorption tower connected to the output end of the dehydration tower, a light-weight removal tower connected to the output end of the adsorption tower, a dust collector and a first filter installed on the connecting pipeline between the adsorption tower and the light-weight removal tower, a heavy-weight removal tower connected to the bottom of the light-weight removal tower, a second filter connected to the top of the heavy-weight removal tower, and a second diaphragm compressor connected to the output end of the second filter. The output end of the second diaphragm compressor outputs the purified CO product. It also includes a first intermediate storage tank and a second intermediate storage tank. The first intermediate storage tank is installed on the connecting pipeline between the first diaphragm compressor and the dewatering tower, and is used to store the compression products of the first diaphragm compressor. The second intermediate storage tank is installed on the connecting pipeline between the second filter and the second diaphragm compressor, and is used to store the CO purified gas to be compressed; The light-weight removal tower is equipped with a first pipeline at its top, and a first condenser is installed on the first pipeline; the heavy-weight removal tower is equipped with a second pipeline at its top, and a second condenser is installed on the second pipeline; the cold nitrogen gas at the outlets of the first and second condensers is connected to the adsorption tower to provide a cold source for the adsorption tower, thereby achieving full utilization of the cooling capacity and saving more than 10% of liquid nitrogen. The adsorption pressure of the adsorption tower is 1.5 ~ 3.0 MPa, and the temperature is -80 ºC ~ -10 ºC; A desiccant is added to the water removal tower, and a desiccant and a carbon dioxide adsorbent are installed in the adsorption tower.

2. As described in claim 1 13 The CO isotope separation tail gas purification device is characterized by... The first condenser is connected to the inner cavity of the light component removal tower and the environment through a first pipeline. The first condenser is connected to a light component discharge pipe for discharging light components. The bottom of the first condenser is also provided with a first reflux pipe that is connected to the inner cavity of the light component removal tower.

3. As described in claim 2 13 The CO isotope separation tail gas purification device is characterized by... The light-weight removal tower has a first liquid separator pipe near the bottom of the tower, which communicates with the inner cavity of the light-weight removal tower. The output end of the first liquid separator pipe is connected to the connecting pipeline between the light-weight removal tower and the heavy-weight removal tower. A first reboiler is provided on the first liquid separator pipe. The bottom of the heavy-weight removal tower has a heavy-weight removal pipeline. The tower body of the heavy-weight removal tower has a second liquid separator pipe near the bottom of the tower, which communicates with the inner cavity of the heavy-weight removal tower. The output end of the second liquid separator pipe is connected to the heavy-weight removal pipeline. A second reboiler is provided on the second liquid separator pipe.

4. The method according to claim 3 13 The CO isotope separation tail gas purification device is characterized by... The second condenser is connected to the inner cavity of the de-weighting tower through a second pipeline. A collection pipe is connected to the second condenser, and a second filter is provided on the collection pipe. A second return pipe connected to the inner cavity of the de-weighting tower is also provided at the bottom of the second condenser.

5. A kind 13 The CO isotope separation tail gas purification method adopts the method described in any one of claims 1 to 4. 13 The CO isotope separation tail gas purification device is characterized by... Includes the following steps: S1: Pressurize the CO tail gas to be purified, and store it under pressure in the first intermediate storage tank. Remove water from the pressurized material and adsorb and remove the preset types of gaseous impurities in the tail gas. S2: Dust removal and filtration of the adsorbed exhaust gas; S3: The filtered tail gas is distilled through a light gas removal tower and a heavy gas removal tower; In step S3, the filtered tail gas enters the middle of the light-light gas removal tower and undergoes a first distillation under the conditions of a bottom temperature of -180 ºC ~ -150 ºC, a top temperature of -181 ºC ~ -151 ºC, and a distillation pressure of 0.3 MPa ~ 2.0 MPa. The vapor phase from the first distillation is discharged through the top of the light-light gas removal tower. The tail gas flow rate entering the light-light gas removal tower is 3 kg / h ~ 30 kg / h, and the light-light gas discharge flow rate at the top of the light-light gas removal tower is 0.10 kg / h ~ 2 kg / h. In step S3, a portion of the bottom liquid from the light-light removal tower is collected and enters the heavy-light removal tower. Secondary distillation is carried out under the conditions of a bottom temperature of -183 ºC ~ -151ºC, a top temperature of -184 ºC ~ -152 ºC, and a rectification pressure of 0.2 MPa - 1.9 MPa. The distillation gas is condensed and output from the top of the heavy-light removal tower. The tail gas flow rate entering the heavy-light removal tower is 2.90 kg / h ~ 28 kg / h, the heavy-light removal flow rate at the bottom of the heavy-light removal tower is 0.10 kg / h ~ 2 kg / h, and the top collection rate of the heavy-light removal tower is 2.80 kg / h ~ 26 kg / h. S4: Filter and compress the distillation gas, and store it under stable pressure in the second intermediate storage tank to obtain a purified CO product.

6. The method according to claim 5 13 The method for purifying CO isotope separation tail gas is characterized by... In step S1, the CO tail gas to be purified is compressed using a diaphragm compressor and sequentially passed into a dehydration tower and an adsorption tower for dehydration and gas adsorption. The temperature of the CO tail gas to be purified is -20 ºC ~ 30 ºC, the pressure of the diaphragm compressor is 1.5 ~ 3.0 MPa, the flow rate of the tail gas in the dehydration tower and adsorption tower is 3 kg / h ~ 30 kg / h, the adsorption pressure of the adsorption tower is 1.5 ~ 3.0 MPa, and the adsorption temperature is -80℃ ~ -10℃.

7. The method according to claim 6 13 The method for purifying CO isotope separation tail gas is characterized by... Condensers are installed at the top of the light-weight removal tower and the heavy-weight removal tower to condense the reflux liquid phase. The reflux ratio of the light-weight removal tower is 30 to 1500, and the reflux ratio of the heavy-weight removal tower is 3 to 50.

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