A method for simultaneous separation 13 C and 18 Method and apparatus for isotopes of O

Abstract

The application discloses a method and device for simultaneously separating 13 C and 18 O isotopes, which comprises the following steps: in a multistage cascade tower composed of n separation units, n>=2, through countercurrent contact of gaseous CO2 and liquid-phase organic amine salt containing CO2, 13 C and 18 O isotopes are exchanged and separated, CO2 is exchanged step by step in the exchange tower of the multistage cascade tower, and the liquid-phase organic amine salt is decomposed and exchanged step by step in the decomposition tank and the exchange tower of the multistage cascade tower. In the application, the chemical exchange method under normal temperature and pressure is adopted, and the application has the characteristics of simple process, easy operation, low requirement for equipment, small investment, stable operation and the like, and can simultaneously produce 13 C and 18 O isotopes in the same set of series-connected devices, greatly reduces the production cost of each isotopic product, has strong market competitiveness, and embodies the development concept of green, economic and circular economy.

Description

Technical Field

[0001] This invention belongs to the field of isotope separation technology, specifically relating to a method for simultaneous separation 13 C and 18 Methods and apparatus for using O isotopes. Background Technology

[0002] Carbon-13 ( 13 C) Urea is one of the gold standards for Helicobacter pylori detection, and the market demand is huge. However, China does not yet have the production capacity for carbon-13 stable isotopes and is completely dependent on imports. Internationally... 13 The only method for producing carbon isotopes is cryogenic distillation, most notably the CO cryogenic distillation method in the United States and the methane cryogenic distillation method in Japan. Both of these methods require the use of toxic and hazardous separation media and need to operate stably and continuously at ultra-low temperatures of -170°C, placing high demands on equipment and resulting in significant energy consumption. Therefore, there is an urgent need to develop a green and easy-to-operate method. 13 The production process of C isotopes has broken the foreign monopoly.

[0003] also, 18 O isotopes, as raw materials for the synthesis of 18F radionuclide, a PET imaging agent, have wide applications in nuclear medicine diagnostics. However, due to... 18 O isotope products have long been dependent on a few companies, resulting in high prices and long supply cycles. Currently, globally... 18 The main method for producing oxygen isotopes is through water distillation. However, due to the numerous gas-liquid phase transformations involved in the cascaded tower process of water distillation, the energy consumption is relatively high. Furthermore, the single-stage separation coefficient is low, requiring significant equipment investment.

[0004] In conclusion, developing green and low-energy-consumption technologies is essential. 13 C and 18 Separation technology for O isotopes is urgently needed. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the purpose of this invention is to provide a method for simultaneously separating... 13 C and 18 Methods and apparatus for using O isotopes.

[0006] To achieve the above objectives and technical effects, the technical solution adopted by this invention is as follows: A simultaneous separation 13 C and 18 The method using O isotopes includes the following steps: In a multi-stage cascade tower consisting of n separation units, where n≥2, the separation is carried out by countercurrent contact of gaseous CO2 and liquid organic amine salts containing CO2.13 C and 18 The O isotope is exchanged and separated, CO2 is exchanged step by step in the exchange tower of the multi-stage cascade tower, and liquid organic amine salts are decomposed and exchanged step by step in the decomposition vessel and exchange tower of the multi-stage cascade tower.

[0007] This invention provides a method for simultaneous separation 13 C and 18 The method using O isotopes includes the following steps: The raw material gas CO2 enters the exchange tower located in the middle and comes into contact with the internal liquid phase, where it is absorbed and undergoes isotope exchange. 13 Carbon (C) enters the liquid phase and accumulates at the bottom of the exchanger. A portion of the liquid phase leaving the bottom of the exchanger is transported to the liquid phase inlet at the top of the next stage exchanger and flows downwards. This process continues until the liquid phase enters the liquid phase inlet at the top of the final stage exchanger, where it flows downwards and undergoes isotope exchange with the rising gas phase. High-purity C is then obtained at the bottom of the final stage exchanger. 13 C-CO2, the other liquid phase leaving the bottom of the exchange tower enters its corresponding connected decomposition vessel, where it is decomposed into gas and liquid phases respectively. The gas phase returns to its corresponding connected exchange tower, flows upward, and exchanges isotopes with the liquid phase. The liquid phase leaving the decomposition vessel returns sequentially to the previous stage decomposition vessel. The liquid phase in the decomposition vessel connected to the intermediate exchange tower is transported to the liquid phase inlet at the top of the current stage exchange tower, flows downward, and exchanges isotopes with the feed gas CO2. The gas phase exiting from the top of the intermediate exchange tower is transported to the gas phase inlet at the bottom of the next-stage exchange tower, flows upward, and contacts the liquid phase flowing down from the top of the tower for isotope exchange. It then enters the gas phase inlet at the bottom of the next-stage exchange tower, and so on, entering the first-stage exchange tower for isotope exchange with the liquid phase flowing down from the top of the first-stage exchange tower. Finally, high-purity gas is obtained at the top of the tower. 18 O-CO2.

[0008] Furthermore, each separation unit includes a connected decomposition vessel and an exchange tower, wherein the previous stage exchange tower in the multi-stage cascaded tower enriches... 13 The liquid phase after step C is transported to the top of the next stage exchange column, and the CO2 gas at the top of the next stage exchange column flows to the bottom of the previous stage exchange column. 13 C isotopes are enriched at the bottom of the final exchange tower. 18 O is enriched at the top of the first-stage exchange tower.

[0009] The present invention also provides a method for simultaneous separation 13 C and 18The device for O isotopes includes a multi-stage cascade tower consisting of n separation units, where n ≥ 2. Each separation unit includes a connected decomposition vessel and an exchange tower. The exchange tower located in the middle is the feed tower for the raw material gas CO2. The bottom of the previous stage exchange tower in the multi-stage cascade tower is connected to the top of the next stage exchange tower. The previous stage exchange tower enriches... 13 The liquid phase after step C is transported to the top of the next stage exchange column, and the CO2 gas at the top of the next stage exchange column flows to the bottom of the previous stage exchange column. 13 C isotopes are enriched at the bottom of the final exchange tower. 18 O is enriched at the top of the first-stage exchange tower.

[0010] Furthermore, the separation unit comprises nine units, namely, a first-level switching tower, a second-level switching tower, a third-level switching tower, a fourth-level switching tower, a fifth-level switching tower, a sixth-level switching tower, a seventh-level switching tower, an eighth-level switching tower, and a ninth-level switching tower. The first-level switching tower, the second-level switching tower, the third-level switching tower, and the fourth-level switching tower are... 18 The O isotope enrichment device, wherein the fifth, sixth, seventh, eighth, and ninth stage exchange towers are... 13 C isotope enrichment device.

[0011] Furthermore, the top of the fifth-stage exchange tower is connected to the gas phase inlet of the bottom of the fourth-stage exchange tower, the top of the fourth-stage exchange tower is connected to the gas phase inlet of the bottom of the third-stage exchange tower, the top of the third-stage exchange tower is connected to the gas phase inlet of the bottom of the second-stage exchange tower, and the top of the second-stage exchange tower is connected to the gas phase inlet of the bottom of the first-stage exchange tower. The carbon dioxide gas exiting from the top outlet of the fifth-stage exchange tower... 18 O is slightly enriched. 13 C is slightly diluted and transported to the fourth-level exchange tower, from where it leaves. 18 O isotopes continuously accumulate in the next higher exchange tower, reaching enrichment at the top of the first exchange tower, resulting in an abundance greater than 98%. 18 O product, waste CO2 gas is discharged from the bottom of the fourth-stage exchange tower.

[0012] Furthermore, the bottom of the fifth-stage exchange tower is connected to the top of the sixth-stage exchange tower, the bottom of the sixth-stage exchange tower is connected to the top of the seventh-stage exchange tower, the bottom of the seventh-stage exchange tower is connected to the top of the eighth-stage exchange tower, and the bottom of the eighth-stage exchange tower is connected to the top of the ninth-stage exchange tower, thus enriching the liquid phase from the bottom of the fifth-stage exchange tower. 13 The liquid phase after stage C is transported to the top of the sixth-stage exchange column and then continuously enriched in the next stage exchange column, achieving enrichment at the bottom of the ninth-stage exchange column, yielding an abundance greater than 99%. 13 Product C.

[0013] Furthermore, the fifth-stage exchange tower has the largest diameter, while the diameters of the exchange towers on the front and rear sides gradually decrease.

[0014] Furthermore, the exchange tower is an exchange section with an inner diameter of 20-5000 mm, and uses structured packing or random high-efficiency packing. The structured packing includes wire mesh corrugated packing, mesh corrugated packing and plate corrugated packing, and the random high-efficiency packing includes θ mesh ring packing, triangular spiral ring and rectangular spiral ring. The packing materials include phosphor bronze, stainless steel, oxidized stainless steel, ceramic, glass and plastic.

[0015] Furthermore, the temperature of the exchange tower is 18-28℃, the temperature of the decomposition vessel is 75-120℃, and the working pressure is 0-5 kPa. The exchange system of the exchange tower uses an organic solution of amines. The solution consists of an organic amine that can absorb carbon dioxide and a solvent. The concentration of the organic amine solution is 0.2-3 mol / L. The organic amine that can absorb carbon dioxide includes one or a combination of several of the following: n-propylamine, dipropylamine, tripropylamine, n-butylamine, sec-butylamine, tert-butylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, tri-n-butylamine, n-hexylamine, di-n-hexylamine, monoethanolamine, diethanolamine, and monopropanolamine. The solvent includes one or a combination of several of the following: methanol, ethanol, propanol, butanol, hexane, n-octane, ethyl acetate, isopropyl acetate, dipropylamine, triethylamine, tripropylamine, isobutylamine, and trimethyl dibutyl ketone.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) This invention can simultaneously produce [products] on the same set of connected devices. 13 C and 18 The two isotope products, O and O, have greatly reduced the production costs of their respective isotope products and have strong market competitiveness.

[0017] 2) This invention uses a chemical exchange method under normal temperature and pressure conditions to produce... 13 C and 18 O isotopes have the advantages of simple process, easy operation, low equipment requirements, low investment and stable operation. They overcome the disadvantages of traditional low temperature distillation methods for CO and methane, such as flammability and explosiveness, high equipment requirements and high operation difficulty. At the same time, they also avoid the disadvantage of large energy consumption in the phase change process of water distillation.

[0018] 3) This invention uses a chemical exchange method to directly produce products with an abundance of over 99%. 13 C isotopes overcome the bottleneck of low-temperature distillation, which can only achieve 93% purity, and the energy consumption and material loss problems caused by the need for secondary conversion distillation.

[0019] 4) This invention uses a chemical exchange method to produce... 13 C and18 O isotopes were used, and systems with high separation coefficients were obtained through solvent screening. The separation coefficients of binary and ternary systems such as di-n-hexylamine / ethanol + n-octane were: α( 13 C / 12 C) = 1.012, α ( 18 O / 16 O) = 1.008, all higher than 13 Cryogenic distillation of 1.01 and 18 The separation coefficient of water distillation using O isotopes is 1.006, requiring fewer theoretical plates and reducing equipment investment.

[0020] 5) This invention uses packing oxidation technology to oxidize the stainless steel surface, which greatly improves the wettability and ductility of the packing surface, allowing the gas and liquid phases to have a larger contact exchange surface on the packing surface, thus greatly improving the separation efficiency per meter of packing.

[0021] 6) The raw materials used in this invention are simple and readily available. The organic reagents are inexpensive and can be recycled within the exchange tower. The isotope distillation process does not require the consumption of organic reagents. Gaseous carbon dioxide is ordinary CO2; this greenhouse gas is converted into valuable organic compounds through chemical exchange. 13 C and 18 O isotope products not only turn waste into treasure, but also overcome the use of toxic and harmful substances in traditional low-temperature distillation processes. The whole process embodies the development concept of green, economical, and circular economy.

[0022] 7) This invention uses a chemical exchange method to produce... 13 C and 18 O isotope production scale-up is relatively simple. At the same time, the exchange tower used in this invention has a larger diameter, which facilitates installation and verification of tower verticality. This overcomes the problems that traditional low-temperature distillation can only increase production capacity by arranging more tubes in parallel, the verticality of the tubes is difficult to install, and the entire unit needs to be shut down if a single tube leaks.

[0023] 8) This invention adopts a liquid-phase cascade process, which directly pumps the organic material containing carbon dioxide from the front tower to the top of the subsequent tower. This greatly reduces the process required by traditional chemical exchange methods in small-scale tests, which involves decomposition and then transporting the gas to the top of the subsequent tower for absorption. This not only greatly reduces the related energy consumption, but also makes the material concentration of each tower relatively stable. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention. Detailed Implementation

[0025] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0026] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0027] Example 1

[0028] like Figure 1 As shown, a method of simultaneous separation 13 C and 18 The O isotope apparatus comprises a multi-stage cascaded tower consisting of nine separation units. Each separation unit includes a decomposition vessel and an exchange tower connected in series. For ease of distinction, the exchange towers connected sequentially from the previous stage to the next stage are designated as the first-stage exchange tower 1, the second-stage exchange tower 2, the third-stage exchange tower 3, the fourth-stage exchange tower 4, the fifth-stage exchange tower 5, the sixth-stage exchange tower 6, the seventh-stage exchange tower 7, the eighth-stage exchange tower 8, and the ninth-stage exchange tower 9. The bottom of the fifth-stage exchange tower 5 is connected to the liquid phase inlet at the top of the sixth-stage exchange tower 6 via a fifth-stage liquid phase pump 51. The bottom of the fifth-stage exchange tower 5 is also connected to the fifth-stage decomposition vessel 52. The fifth-stage decomposition vessel 52 is connected to the liquid phase inlet at the top of the fifth-stage exchange tower 5 via a transfer pump 53. The top of the fifth-stage exchange tower 5 is connected to the gas phase inlet at the bottom of the fourth-stage exchange tower 4 via a fifth-stage gas phase pump 54, and so on.

[0029] First-level exchange tower 1, second-level exchange tower 2, third-level exchange tower 3, and fourth-level exchange tower 4 are 18 The carbon dioxide gas exiting from the top outlet of the fifth-stage exchange tower (5th stage) of the O isotope enrichment device contains... 18 O is slightly enriched, while 13 C is slightly diluted, and the above gas is transported to the fourth-stage exchange tower 4 using the fifth-stage gas phase pump 54, and then... 18 O isotopes continuously accumulate in the preceding exchange tower, eventually... 18 O was enriched at the top of the first-stage exchange tower 1, yielding an abundance greater than 98%. 18 O product, waste CO2 gas is discharged from the bottom of the fourth-stage exchange tower 4.

[0030] Level 5 Exchange Tower 5, Level 6 Exchange Tower 6, Level 7 Exchange Tower 7, Level 8 Exchange Tower 8, and Level 9 Exchange Tower 9 are... 13 The C isotope enrichment device, consisting of five exchange towers, with the first-stage exchange tower being the most enriched.13 The liquid phase after stage C is transported to the top of the subsequent exchange tower. The CO2 gas at the top of the subsequent exchange tower is returned to the bottom of the preceding exchange tower. Therefore, the feed gas CO2 enters from the fifth-stage exchange tower (tower 5). 13 C isotopes are continuously transferred from the fifth-stage exchange tower (stage 5) to subsequent exchange towers, eventually... 13 C isotopes were enriched at the bottom of the ninth-stage exchange tower (stage 9), yielding an abundance greater than 99%. 13 Product C ( 13 C-CO2).

[0031] It should be noted that the fifth-stage exchange tower 5, located in the center of the multi-stage cascade tower, is the feed tower for the raw material gas CO2 and has the largest tower diameter. The tower diameters of the exchange towers on the front and rear sides gradually decrease.

[0032] The exchange tower is the exchange section, with an inner diameter of 20-5000 mm. The exchange tower uses either structured or random high-efficiency packing. The packing includes structured packing and random packing. Structured packing includes wire mesh corrugated packing, mesh corrugated packing, and plate corrugated packing. Random high-efficiency packing includes θ-ring packing, triangular spiral rings, rectangular spiral rings, etc. Packing materials include phosphor bronze, stainless steel, oxidized stainless steel, ceramics, glass, and plastics.

[0033] The temperature of the exchange tower is 18-28℃; the temperature of the decomposition vessel is 75-120℃, and the working pressure is 0-5kpa.

[0034] The exchange system of the exchange tower uses an organic solution of amines. The solution consists of organic amines that can absorb carbon dioxide and organic solvents. The concentration of the organic amine solution is 0.2-3 mol / L. Organic amines that can absorb carbon dioxide include: n-propylamine, dipropylamine, tripropylamine, n-butylamine, sec-butylamine, tert-butylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, tri-n-butylamine, n-hexylamine, di-n-hexylamine, monoethanolamine, diethanolamine, and monopropanolamine. Solvents include: methanol, ethanol, propanol, butanol, hexane, n-octane, ethyl acetate, isopropyl acetate, dipropylamine, triethylamine, tripropylamine, isobutylamine, and trimethyl dibutyl ketone, or a combination of two of these.

[0035] A simultaneous separation 13 C and 18 The method using O isotopes includes the following steps: Within a multi-stage cascade tower consisting of nine separation units, the separation is achieved through countercurrent flow of gaseous CO2 and liquid organic amine salts containing CO2. 13 C and 18 Exchange separation of O isotopes 13 C and 18The separation of O isotopes is achieved through the exchange of isotope-containing liquid and CO2 gas on the surface of the packing material in the exchange tower. CO2 is continuously exchanged in each exchange tower, and the liquid organic amine is continuously decomposed and exchanged in each decomposition vessel and exchange tower. The specific steps of this method include: The raw material gas CO2 enters the fifth-stage exchange tower 5 through the feed inlet located in the middle of the tower, and comes into contact with the liquid phase falling from the top of the fifth-stage exchange tower 5 to carry out isotope exchange. 13 C enters the liquid phase and accumulates at the bottom of the fifth-stage exchanger (5). A portion of the liquid phase leaving the bottom of the fifth-stage exchanger (5) is pumped by the fifth-stage liquid phase pump (51) to the liquid phase inlet at the top of the next-stage exchanger (sixth-stage exchanger (6)) and flows downwards. A portion leaving the bottom of the sixth-stage exchanger (6) is pumped by the sixth-stage liquid phase pump (61) to the liquid phase inlet at the top of the next-stage exchanger (seventh-stage exchanger (7)) and flows downwards, and so on. The liquid phase enters the liquid phase inlet at the top of the final-stage exchanger (ninth-stage exchanger (9)) and flows downwards, undergoing isotope exchange with the rising gas phase. High-purity C is obtained at the bottom of the final-stage exchanger. 13 C-CO2; The remaining liquid phase exiting from the bottom of the sixth-stage exchange tower 6, the seventh-stage exchange tower 7, the eighth-stage exchange tower 8, and the ninth-stage exchange tower 9 enters their respective connected decomposition vessels, namely the sixth-stage decomposition vessel 62, the seventh-stage decomposition vessel 71, the eighth-stage decomposition vessel 81, and the ninth-stage decomposition vessel 91, where it is decomposed into gas and liquid phases, respectively. The gas phase in the sixth-stage decomposition vessel 62, the seventh-stage decomposition vessel 71, the eighth-stage decomposition vessel 81, and the ninth-stage decomposition vessel 91 returns to their respective connected exchange towers, namely the sixth-stage exchange tower 6, the seventh-stage exchange tower 7, the eighth-stage exchange tower 8, and the ninth-stage decomposition vessel 91. The liquid phase flows upward in the nine-stage exchange tower 9 and exchanges isotopes with the liquid phase flowing down from the top of the tower. The liquid phases leaving the sixth-stage decomposition vessel 62, the seventh-stage decomposition vessel 71, the eighth-stage decomposition vessel 81, and the ninth-stage decomposition vessel 91 return to the previous stage decomposition vessel, namely the fifth-stage decomposition vessel 52, the sixth-stage decomposition vessel 62, the seventh-stage decomposition vessel 71, and the eighth-stage decomposition vessel 81, respectively. The liquid phase of the fifth-stage decomposition vessel 52 is sent to the liquid phase inlet at the top of the fifth-stage exchange tower 5 by the transfer pump 53, flows downward, absorbs the raw material gas CO2, and exchanges isotopes with the rising gas phase. The gas phase exiting from the top of the fifth-stage exchange tower 5 is sent to the gas phase inlet at the bottom of the fourth-stage exchange tower 4 by the fifth-stage gas phase pump 54, flows upward, and contacts the liquid phase flowing down from the top of the tower for isotope exchange. The gas phase exiting from the top of the fourth-stage exchange tower 4 is enriched... 18 The gaseous phase of O enters the gas inlet at the bottom of the third-stage exchange column 3, and so on, entering the first-stage exchange column 1, where it undergoes isotope exchange with the liquid phase flowing down from the top of the first-stage exchange column 1. Finally, high-purity O is obtained at the top of the column. 18O-CO2. The liquid phases flowing out from the bottom of the first-stage exchange tower 1, the second-stage exchange tower 2, the third-stage exchange tower 3, and the fourth-stage exchange tower 4 respectively enter their corresponding connected decomposition vessels, namely the first-stage decomposition vessel 11, the second-stage decomposition vessel 21, the third-stage decomposition vessel 31, and the fourth-stage decomposition vessel 41, where they are decomposed into gas and liquid phases. The liquid phases are then pumped by liquid phase pumps into the liquid phase inlets at the top of the corresponding exchange towers (first-stage exchange tower 1, second-stage exchange tower 2, third-stage exchange tower 3, and fourth-stage exchange tower 4). The gas phases from the first-stage decomposition vessels 11, second-stage decomposition vessels 21, and third-stage decomposition vessels 31 sequentially enter the gas phase inlets at the bottom of the next-stage exchange tower for isotope exchange again. The gas phase decomposed in the fourth-stage decomposition vessel 41 is discharged as waste gas.

[0036] Example 2

[0037] On nine cascaded towers, each 30 meters high. 13 C and 18 O isotope separation. The separation system was 1.5 mol / L di-n-hexylamine / 10% ethanol + 90% n-octane. The diameters of the first-stage exchange tower 1, second-stage exchange tower 2, third-stage exchange tower 3, fourth-stage exchange tower 4, fifth-stage exchange tower 5, sixth-stage exchange tower 6, seventh-stage exchange tower 7, eighth-stage exchange tower 8, and ninth-stage exchange tower 9 were 57 mm, 89 mm, 133 mm, 159 mm, 273 mm, 219 mm, 159 mm, 108 mm, and 76 mm, respectively. Exchange towers with a diameter greater than 100 mm used stainless steel structured packing, while exchange towers with a diameter less than 100 mm used triangular spiral packing. The packing material is used. The operating temperature of the above 9 towers is 18℃, the pressure is 5kpa, the heating temperature of the decomposition vessel is 120℃, and the operating flow rates of the first-stage exchange tower 1, the second-stage exchange tower 2, the third-stage exchange tower 3, the fourth-stage exchange tower 4, the fifth-stage exchange tower 5, the sixth-stage exchange tower 6, the seventh-stage exchange tower 7, the eighth-stage exchange tower 8, and the ninth-stage exchange tower 9 are 5L / h, 16L / h, 24L / h, 40L / h, 80L / h, 60L / h, 45L / h, 30L / h, and 12L / h, respectively.

[0038] In this embodiment, the raw material gas CO2 enters from the fifth-stage exchange tower (tower 5) and reacts with the liquid organic amine salt containing CO2 falling from the tower. 13 C isotope exchange. 13 C isotopes are enriched at the bottom of the fifth-stage exchange tower (stage 5). 18 O isotopes are enriched at the top of the fifth-stage exchange tower 5. Then, the initially enriched isotopes are pumped away from the bottom of the fifth-stage exchange tower 5 by the fifth-stage liquid pump 51. 13 The organic solution C is pumped to the top of the sixth-stage exchange column 6, where it continues to exchange with the rising CO2 gas, finally reaching the bottom of the ninth-stage exchange column 9 to obtain 99.2% CO2. 13C₂-CO₂. Preliminary enrichment at the top of the fifth-stage exchange tower. 18 O-CO2 is pumped to the fourth-stage exchange tower 4 via the fifth-stage gas-phase pump 54, where it continues to react with the liquid-phase organic amine salt containing CO2 in the fourth-stage exchange tower 4. 18 O isotope exchange 18 O isotopes continue to be enriched in the preceding gas-phase exchange towers. Waste gas is discharged from the bottom of the fourth-stage exchange tower (4th stage), while 70% is enriched at the top of the first-stage exchange tower (1st stage). 18 O-CO2.

[0039] Example 3

[0040] Conducted on nine cascaded towers, each 30 meters high. 13 C and 18 O isotope separation. The separation system was 1.5 mol / L di-n-hexylamine / 5% ethanol + 95% triethylamine. The diameters of the first-stage exchange tower 1, second-stage exchange tower 2, third-stage exchange tower 3, fourth-stage exchange tower 4, fifth-stage exchange tower 5, sixth-stage exchange tower 6, seventh-stage exchange tower 7, eighth-stage exchange tower 8, and ninth-stage exchange tower 9 were 32 mm, 57 mm, 89 mm, 159 mm, 273 mm, 219 mm, 159 mm, 108 mm, and 76 mm, respectively. Exchange towers with a diameter greater than 100 mm used oxidized stainless steel structured packing, while those with a diameter less than 100 mm used rectangular spiral random packing. The operating temperature of the exchange towers was 22℃, the pressure was 3 kPa, and the heating temperature of the decomposition vessel was 110℃. The operating flow rates of the first-level switching tower 1, the second-level switching tower 2, the third-level switching tower 3, the fourth-level switching tower 4, the fifth-level switching tower 5, the sixth-level switching tower 6, the seventh-level switching tower 7, the eighth-level switching tower 8, and the ninth-level switching tower 9 are 2L / h, 8L / h, 18L / h, 35L / h, 80L / h, 60L / h, 45L / h, 30L / h, and 12L / h, respectively.

[0041] In this embodiment, the raw material gas CO2 enters from the fifth-stage exchange tower (tower 5) and reacts with the liquid organic amine salt containing CO2 falling from the tower. 13 C isotope exchange. 13 C isotopes are enriched at the bottom of the fifth-stage exchange tower (stage 5). 18 O isotopes are enriched at the top of the fifth-stage exchange tower 5. Then, the initially enriched isotopes are pumped away from the bottom of the fifth-stage exchange tower 5 by the fifth-stage liquid pump 51. 13 The organic solution C is pumped to the top of the sixth-stage exchange column 6, where it continues to exchange with the rising CO2 gas, finally reaching the bottom of the ninth-stage exchange column 9 to obtain 99.3% CO2. 13 C-CO2. Preliminary enrichment at the top of the fifth-stage exchange tower. 18O-CO2 is pumped to the fourth-stage exchange tower 4 via the fifth-stage gas-phase pump 54, where it continues to react with the liquid-phase organic amine salt containing CO2 in the fourth-stage exchange tower 4. 18 O isotope exchange 18 O isotopes continue to be enriched in the preceding gas-phase exchange towers. Waste gas is discharged from the bottom of the fourth-stage exchange tower (4th stage), while 98% isotopes are enriched at the top of the first-stage exchange tower (1st stage). 18 O-CO2.

[0042] Example 4

[0043] Conducted on nine cascaded towers, each 30 meters high. 13 C and 18 O isotope separation. The separation system was 1 mol / L di-n-butylamine / isopropyl acetate. The diameters of the first-stage exchange tower 1, second-stage exchange tower 2, third-stage exchange tower 3, fourth-stage exchange tower 4, fifth-stage exchange tower 5, sixth-stage exchange tower 6, seventh-stage exchange tower 7, eighth-stage exchange tower 8, and ninth-stage exchange tower 9 were 32 mm, 57 mm, 89 mm, 159 mm, 273 mm, 219 mm, 159 mm, 108 mm, and 76 mm, respectively. Exchange towers with a diameter greater than 100 mm used oxidized stainless steel structured packing, while exchange towers with a diameter less than 100 mm used θ-dispersed packing. The operating temperature of the exchange towers was 25℃, the pressure was 2 kPa, and the heating temperature of the decomposition vessel was 105℃. The operating flow rates of the first-level switching tower 1, the second-level switching tower 2, the third-level switching tower 3, the fourth-level switching tower 4, the fifth-level switching tower 5, the sixth-level switching tower 6, the seventh-level switching tower 7, the eighth-level switching tower 8, and the ninth-level switching tower 9 are 2.5L / h, 10L / h, 20L / h, 40L / h, 80L / h, 65L / h, 48L / h, 32L / h, and 15L / h, respectively.

[0044] In this embodiment, the raw material gas CO2 enters from the fifth-stage exchange tower (tower 5) and reacts with the liquid organic amine salt containing CO2 falling from the tower. 13 C isotope exchange. 13 C isotopes are enriched at the bottom of the fifth-stage exchange tower (stage 5). 18 O isotopes are enriched at the top of the fifth-stage exchange tower 5. Then, the initially enriched isotopes are pumped away from the bottom of the fifth-stage exchange tower 5 by the fifth-stage liquid pump 51. 13 The organic solution C is pumped to the top of the sixth-stage exchange column 6, where it continues to exchange with the rising CO2 gas, finally reaching the bottom of the ninth-stage exchange column 9 to obtain 99.4% CO2. 13 C-CO2. Preliminary enrichment at the top of the fifth-stage exchange tower. 18 O-CO2 is pumped to the fourth-stage exchange tower 4 via the fifth-stage gas-phase pump 54, where it continues to react with the liquid-phase organic amine salt containing CO2 in the fourth-stage exchange tower 4. 18 O isotope exchange18 O isotopes continue to be enriched in the gas phase at the previous stage of the exchange tower. Waste gas is discharged from the bottom of the fourth stage exchange tower (4th stage), and 98.1% is enriched at the top of the first stage exchange tower (1st stage). 18 O-CO2.

[0045] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0046] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for simultaneous separation 13 C and 18 The method using O isotopes is characterized by... Includes the following steps: In a multi-stage cascade tower consisting of n separation units, the separation is carried out by countercurrent contact between gaseous CO2 and liquid organic amine salts containing CO2. 13 C and 18 The O isotope is exchanged and separated, CO2 is exchanged step by step in the exchange tower of the multi-stage cascade tower, and liquid organic amine salts are decomposed and exchanged step by step in the decomposition vessel and exchange tower of the multi-stage cascade tower; wherein, each separation unit includes a decomposition vessel and an exchange tower connected to each other. The raw material gas CO2 enters the exchange tower located in the middle and comes into contact with the internal liquid phase, where it is absorbed and undergoes isotope exchange. 13 Carbon (C) enters the liquid phase and accumulates at the bottom of the exchanger. A portion of the liquid phase leaving the bottom of the exchanger is transported to the liquid phase inlet at the top of the next stage exchanger and flows downwards. This process continues until the liquid phase enters the liquid phase inlet at the top of the final stage exchanger, where it flows downwards and undergoes isotope exchange with the rising gas phase. High-purity C is then obtained at the bottom of the final stage exchanger. 13 C-CO2, the other liquid phase leaving the bottom of the exchange tower enters its corresponding connected decomposition vessel, where it is decomposed into gas and liquid phases respectively. The gas phase returns to its corresponding connected exchange tower, flows upward, and exchanges isotopes with the liquid phase. The liquid phase leaving the decomposition vessel returns sequentially to the previous stage decomposition vessel. The liquid phase in the decomposition vessel connected to the intermediate exchange tower is transported to the liquid phase inlet at the top of the current stage exchange tower, flows downward, and exchanges isotopes with the feed gas CO2. The gas phase exiting from the top of the intermediate exchange tower is transported to the gas phase inlet at the bottom of the next-stage exchange tower, flows upward, and contacts the liquid phase flowing down from the top of the tower for isotope exchange. It then enters the gas phase inlet at the bottom of the next-stage exchange tower, and so on, entering the first-stage exchange tower for isotope exchange with the liquid phase flowing down from the top of the first-stage exchange tower. Finally, high-purity gas is obtained at the top of the tower. 18 O-CO2.

2. A method for simultaneous separation according to claim 1 13 C and 18 The method using O isotopes is characterized by... The upper-level exchange tower in the multi-stage cascaded tower is enriched 13 The liquid phase after step C is transported to the top of the next stage exchange column, and the CO2 gas at the top of the next stage exchange column flows to the bottom of the previous stage exchange column. 13 C isotopes are enriched at the bottom of the final exchange tower. 18 O is enriched at the top of the first-stage exchange tower.

3. A method for simultaneous separation 13 C and 18 The device for O isotope is characterized by, It is used to implement the simultaneous separation as described in claim 1 or 2. 13 C and 18 The method using O isotopes involves an apparatus comprising a multi-stage cascade tower consisting of n separation units. Each separation unit includes a connected decomposition vessel and an exchange tower. The exchange tower, located in the middle, serves as the feed tower for the raw material gas CO2. The bottom of the previous stage exchange tower is connected to the top of the next stage exchange tower, and the previous stage exchange tower enriches... 13 The liquid phase after step C is transported to the top of the next stage exchange column, and the CO2 gas at the top of the next stage exchange column flows to the bottom of the previous stage exchange column. 13 C isotopes are enriched at the bottom of the final exchange tower. 18 O is enriched at the top of the first-stage exchange tower.

4. A method for simultaneous separation according to claim 3 13 C and 18 The device for O isotope is characterized by, The separation unit consists of nine units, sequentially designated as a first-level switching tower, a second-level switching tower, a third-level switching tower, a fourth-level switching tower, a fifth-level switching tower, a sixth-level switching tower, a seventh-level switching tower, an eighth-level switching tower, and a ninth-level switching tower. The first-level switching tower, the second-level switching tower, the third-level switching tower, and the fourth-level switching tower are... 18 The O isotope enrichment device, wherein the fifth, sixth, seventh, eighth, and ninth stage exchange towers are... 13 C isotope enrichment device.

5. A method for simultaneous separation according to claim 4 13 C and 18 The device for O isotope is characterized by, The top of the fifth-stage exchange tower is connected to the bottom of the fourth-stage exchange tower, the top of the fourth-stage exchange tower is connected to the bottom of the third-stage exchange tower, the top of the third-stage exchange tower is connected to the bottom of the second-stage exchange tower, and the top of the second-stage exchange tower is connected to the bottom of the first-stage exchange tower. Carbon dioxide gas exits from the top outlet of the fifth-stage exchange tower. 18 O is slightly enriched. 13 C is slightly diluted and transported to the fourth-level exchange tower, from where it leaves. 18 O isotopes continuously accumulate in the next higher exchange tower, reaching enrichment at the top of the first exchange tower, resulting in an abundance greater than 98%. 18 O product, waste CO2 gas is discharged from the bottom of the fourth-stage exchange tower.

6. A method for simultaneous separation according to claim 4 13 C and 18 The device for O isotope is characterized by, The bottom of the fifth-stage exchange tower is connected to the top of the sixth-stage exchange tower, the bottom of the sixth-stage exchange tower is connected to the top of the seventh-stage exchange tower, the bottom of the seventh-stage exchange tower is connected to the top of the eighth-stage exchange tower, and the bottom of the eighth-stage exchange tower is connected to the top of the ninth-stage exchange tower. The liquid phase is enriched from the bottom of the fifth-stage exchange tower. 13 The liquid phase after stage C is transported to the top of the sixth-stage exchange column and then continuously enriched in the next stage exchange column, achieving enrichment at the bottom of the ninth-stage exchange column, yielding an abundance greater than 99%. 13 Product C.

7. A method for simultaneous separation according to claim 4 13 C and 18 The device for O isotope is characterized by, The fifth-stage exchange tower has the largest diameter, while the diameters of the exchange towers on the front and rear sides gradually decrease.

8. A method for simultaneous separation according to claim 3 13 C and 18 The device for O isotope is characterized by, The exchange tower is an exchange section with an inner diameter of 20-5000 mm. It uses structured packing or random high-efficiency packing. The structured packing includes wire mesh corrugated packing, mesh corrugated packing and plate corrugated packing. The random high-efficiency packing includes θ mesh ring packing, triangular spiral ring and rectangular spiral ring. The packing materials include phosphor bronze, stainless steel, ceramic, glass and plastic.

9. A method for simultaneous separation according to claim 3 13 C and 18 The device for O isotope is characterized by, The temperature of the exchange tower is 18-28℃, the temperature of the decomposition vessel is 75-120℃, and the working pressure is 0-5 kPa. The exchange system of the exchange tower uses an organic solution of amines. The solution consists of an organic amine that can absorb carbon dioxide and a solvent. The concentration of the organic amine solution is 0.2-3 mol / L. The organic amine that can absorb carbon dioxide includes one or a combination of several of the following: n-propylamine, dipropylamine, tripropylamine, n-butylamine, sec-butylamine, tert-butylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, tri-n-butylamine, n-hexylamine, di-n-hexylamine, monoethanolamine, diethanolamine, and monopropanolamine. The solvent includes one or a combination of several of the following: methanol, ethanol, propanol, butanol, hexane, n-octane, ethyl acetate, isopropyl acetate, dipropylamine, triethylamine, tripropylamine, isobutylamine, and trimethyl dibutyl ketone.

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