A separation 14 Continuous production method of C isotopes

Abstract

This application belongs to the field of carbon isotope separation technology and aims to solve the problem of separation 14 C isotope equilibrium time is long and separation efficiency is low. 14 The continuous production method of C isotope is to continuously introduce the 14 C of CO2 raw gas, and the composite absorbent absorbs the reaction, so that 14 C is enriched in the liquid phase, 12 C is enriched in the gas phase and enters the first-level extraction and analysis kettle to decompose into enriched 14 C CO2 gas and composite absorbent, enrichment 14 The CO2 gas from C enters the first-stage absorption and enrichment tower, and each stage enriches the CO2 gas from the decomposition kettle. 14 The CO2 gas of C enters the next level absorption and enrichment tower, repeats the reaction process, and the composite absorbent extracted by the first level extraction and decomposition kettle is transported to the absorption and extraction towers of each level or transported to the absorption and enrichment towers of each level. This application adopts liquid phase mixing, shortens the equilibrium time, improves the separation efficiency, and realizes continuous and efficient separation. 14 C isotope.

Description

Technical Field

[0001] This application belongs to the field of carbon isotope separation technology, and in particular relates to a method for separating 14 A method for the continuous production of C isotopes. Background Art

[0002] Waste discharged from nuclear power plants includes 14 C, 14 The emission of C has become a key issue. If these emissions are treated by volume reduction and separation and recovery, 14 C isotopes will have significant social and economic benefits. 14 C isotope products can not only produce high value-added products, but also reduce nuclear pollution and protect the ecological environment.

[0003] at present, 14 The main C isotope separation processes with promising industrialization prospects are chemical exchange and cryogenic distillation. Both methods have the disadvantages of low separation efficiency, high energy consumption, and long equilibrium time. In particular, the long equilibrium time is a problem for high abundance C isotope separation. 14 The equilibrium of C isotope separation often takes hundreds of days, which is the biggest problem in the start-up phase. Therefore, how to reduce the equilibrium time is the key. 14 An important research direction of C isotope separation. Chinese patent CN202111084972.X discloses a method for separating carbon 14 isotopes. This separation method performs isotope separation by means of a gas phase cascade. The bottom of the first-stage decomposition kettle is connected to the top of the first-stage exchange tower through a liquid delivery pump, and the bottoms of the decomposition kettles of other stages other than the first stage are connected to the first-stage decomposition kettle through a liquid pipeline 2. This separation method eliminates the absorption tower at each stage, and the separation system is closer to an ideal cascade, which reduces the separation efficiency of the exchange tower. Although it can reduce energy consumption, it does not solve the problem. 14 The problems of long C isotope separation equilibrium time and low separation efficiency. Summary of the Invention

[0004] The purpose of this application is to provide a separation 14 The continuous production method of C isotopes solves the problem of separation by existing separation methods. 14 The long equilibrium time of C isotopes and low separation efficiency are solved to achieve continuous and efficient separation. 14 C isotope.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] A separation 14 A method for continuous production of C isotopes, comprising:

[0007] S1: Continuously introduce the liquid containing 14 The CO2 raw gas of C enters the first-level absorption and extraction tower and undergoes absorption reaction with the countercurrent composite absorbent. The composite absorbent that has absorbed CO2 continues to undergo exchange reaction with the gas phase CO2. 14 C is enriched in the liquid phase, 12 C is enriched in the gas phase;

[0008] S2: Enrichment 14 The composite absorption liquid of C enters the first-level extraction and decomposition kettle and is decomposed into enriched 14 C CO2 gas and composite absorbent, enrichment 14 The CO2 gas from C enters the first-stage absorption and enrichment tower;

[0009] S3: enrichment from the top of each level of enrichment and analysis kettle 14 The CO2 gas from C enters the next level absorption and enrichment tower, and is enriched 14 The CO2 gas and composite absorption liquid of C are repeatedly absorbed and exchanged;

[0010] S4: The composite absorbent extracted by heating in the first-stage extraction and desorption kettle is transported to the absorption and extraction towers at various levels or to the absorption and enrichment towers at various levels to circulate and use the composite absorbent;

[0011] S5: After absorption-exchange reaction, it is discharged through the three-stage enrichment and desorption kettle 14 CO2 gas, part of the gas returns to the three-stage absorption and enrichment tower, and part of the gas is used as the product 14 CO2 gas is extracted and discharged through the first-level absorption and extraction tower 12 CO2 gas.

[0012] As an practicable method, the composite absorbent flows in a countercurrent manner in a primary absorption and enrichment tower, and the composite absorption liquid that has absorbed the CO2 raw gas undergoes an exchange reaction with the countercurrent CO2 raw gas in the extraction section of the primary absorption and extraction tower.

[0013] As an implementable approach, 14 The intake volume of CO2 raw gas of C is 2L / h~20000L / h, and the feed concentration of composite absorbent is 0.01mol / L~5mol / L.

[0014] As a feasible method, the first stage extraction and decomposition kettle is heated to decompose into enrichment 14 C of CO2 gas and composite absorbent, wherein the enriched 14 The CO2 in C enters the middle section of the next absorption and extraction tower, and repeats the process of the first-stage absorption and extraction tower and the extraction and desorption kettle until the last stage of extraction and desorption kettle.

[0015] As an practicable method, the composite absorbent heated and decomposed by the first-stage extraction and decomposition kettle is transported to the top inlet of the second-stage absorption and enrichment tower by a liquid transfer pump, the decomposed composite absorbent of the second-stage enrichment and decomposition kettle is transported to the top inlet of the first-stage absorption and enrichment tower by a liquid phase transfer pump, the composite absorbent of the first-stage enrichment and decomposition kettle is transported to the top inlet of the tertiary absorption and enrichment tower by a liquid phase transfer pump, and the tertiary enrichment and decomposition kettle is transported to the top inlet of the first-stage absorption and extraction tower by a liquid phase transfer pump, thereby forming a circulating flow of the composite absorbent.

[0016] As a feasible method, the temperature in each stage of the absorption and extraction tower and each stage of the absorption and enrichment tower is 10°C~40°C, and the pressure in the tower does not exceed 0.15MPa.

[0017] As an practicable manner, the composite absorbent is a mixed solution of diethanolamine and ethanol, and the concentration of diethanolamine is 1 mol / L.

[0018] As an practicable method, the absorption and extraction tower adopts two stages and the absorption and enrichment tower adopts five stages for separation, including:

[0019] Continuously introduce 14 The CO2 raw gas of C undergoes absorption-exchange reaction with the composite absorbent flowing from the top of the tower in the first absorption and extraction tower, and after passing through the second absorption and extraction tower, 14 The C isotope is gradually exchanged into the composite absorption liquid;

[0020] Absorption and extraction 14 The composite absorption liquid of C is heated and decomposed into enriched 14 The CO2 gas and composite absorbent of C, the composite absorbent of the first extraction and analysis kettle is transported to the top of the second absorption and extraction tower for reflux, and the composite absorbent of the second extraction and analysis kettle is transported to the top of the first absorption and extraction tower for reflux. After the second extraction and analysis kettle is analyzed, the enrichment 14 The CO2 gas from C enters the middle section of the first-stage absorption and enrichment tower;

[0021] Absorption enrichment 14 The composite absorption liquid of C is heated and decomposed into enriched 14 C isotope CO2 gas and composite absorbent, enriched in each stage of desorption reactor 14 The C isotope CO2 gas flows into the middle of the next-stage absorption and enrichment tower; the composite absorbent of the first-stage enrichment and desorption kettle is transported to the top of the third-stage absorption and enrichment tower for reflux, the composite absorbent of the third-stage enrichment and desorption kettle is transported to the top of the fifth-stage absorption and enrichment tower for reflux, the composite absorbent of the fifth-stage enrichment and desorption kettle is transported to the top of the second-stage absorption and enrichment tower for reflux, the composite absorbent of the second-stage enrichment and desorption kettle is transported to the top of the fourth-stage absorption and enrichment tower for reflux, and the composite absorbent of the fourth-stage enrichment and desorption kettle is transported to the top of the first-stage absorption and enrichment tower for reflux;

[0022] Discharged from the top of the five-stage enrichment and desorption kettle 14 CO2 gas is discharged from the first-level absorption and extraction tower 12 CO2 gas.

[0023] As an implementable approach, 14 The CO2 feed gas feed rate of C is 120L / h. 14 The abundance of C is 1.1%, the temperature in each level of absorption and extraction tower and absorption and enrichment tower is 25°C, and the pressure is 0.1 MPa.

[0024] In addition, the present application also provides a separation 14 A continuous production device for C isotopes, which implements the above method, comprises a first-stage absorption and extraction tower, a first-stage absorption and enrichment tower, a second-stage absorption and enrichment tower, a third-stage absorption and enrichment tower, a first-stage extraction and desorption kettle, a first-stage enrichment and desorption kettle, a second-stage enrichment and desorption kettle, and a third-stage enrichment and desorption kettle;

[0025] The first-level absorption and extraction tower is connected to the first-level extraction and decomposition kettle and the first-level absorption and enrichment tower, the first-level extraction and decomposition kettle is also connected to the first-level absorption and enrichment tower and the second-level absorption and enrichment tower, the first-level absorption and enrichment tower is also connected to the second-level absorption and enrichment tower and the second-level enrichment and decomposition kettle, the first-level enrichment and decomposition kettle is also connected to the second-level absorption and enrichment tower and the tertiary absorption and enrichment tower, the second-level absorption and enrichment tower is also connected to the second-level enrichment and decomposition kettle and the tertiary absorption and enrichment tower, the second-level enrichment and decomposition kettle is also connected to the tertiary absorption and enrichment tower, the tertiary absorption and enrichment tower is also connected to the tertiary enrichment and decomposition kettle, and the tertiary enrichment and decomposition kettle is also connected to the first-level absorption and extraction tower.

[0026] Compared with the prior art, the separation provided by this application 14 The continuous production method of C isotopes has the following beneficial effects:

[0027] This method uses 14 In the square cascade for C isotope separation, the gas phase flows step by step in the exchange towers, and the liquid phase does not flow in the cascade order, but adopts a mixed flow process of staggered mixed flow between the exchange towers. This mixed flow process has significant advantages in the start-up stage. 14 The C isotope abundance gradient is larger than that of the traditional process, which makes the chemical exchange process have a greater mass transfer driving force, improves the separation efficiency, and obtains 14 The C isotope abundance is even higher, reaching over 99%.

[0028] More importantly, the present invention adopts liquid phase mixing flow to shorten the equilibrium time, which is beneficial to 14 C isotope separation is of great significance and is also an important guarantee for achieving industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for the technical description.

[0030] Figure 1 Separation provided for this application 14 Flowchart of the continuous production method of C isotopes;

[0031] Figure 2 Separation provided for this application 14 Schematic diagram of the apparatus used in the continuous production method of C isotopes.

[0032] Description of reference numerals:

[0033] 1. Primary absorption and extraction tower; 2. Primary absorption and enrichment tower; 3. Secondary absorption and enrichment tower; 4. Third-stage absorption and enrichment tower; 5. Primary extraction and desorption kettle; 6. Primary enrichment and desorption kettle; 7. Secondary enrichment and desorption kettle; 8. Third-stage enrichment and desorption kettle; 9. CO2 raw gas; 10. Composite absorbent; 11. Liquid phase feed pump. DETAILED DESCRIPTION

[0034] The following is further explained in detail through specific implementation methods.

[0035] See also Figure 1 and Figure 2 This application discloses a method for separating 14 The continuous production method of C isotopes comprises the following steps:

[0036] S1: The composite absorbent 10 is sent to the absorption and extraction towers and the absorption and enrichment towers at each level through the liquid phase feed pump 11, and the liquid containing 14 The CO2 raw gas 9 of C, the CO2 raw gas 9 reaches the absorption section of the first absorption and extraction tower 1 through various absorption and extraction towers, and undergoes absorption reaction with the composite absorbent 10 flowing in the tower in the reverse direction. The composite absorption liquid that has absorbed the CO2 raw gas 9 undergoes exchange reaction with the countercurrent CO2 raw gas 9 in the extraction section of the first absorption and extraction tower 1. 14 C is enriched in the liquid phase, 12 C is enriched in the gas phase. The composite agent that absorbs CO2 is a composite absorption liquid.

[0037] S2: Enriched 14 The composite absorption liquid of C enters the first-level extraction and analysis kettle 5, and is decomposed again into the enriched 14 C of CO2 gas and composite absorbent 10, which is enriched 14 The CO2 in C enters the middle section of the first-stage absorption and enrichment tower 2, and begins the absorption-exchange reaction process in the enrichment section.

[0038] S3: In the enrichment tower process, each stage of enrichment and decomposition kettle top enrichment14 The CO2 gas from C enters the middle section of the next level absorption and enrichment tower and is enriched. 14 C of CO2 gas and composite absorption liquid repeated absorption-exchange reaction process.

[0039] S4: The composite absorbent 10 heated and decomposed by the first-stage extraction and decomposition kettle 5 is no longer transported in the order of cascade, but can be transported to the middle section of other-stage absorption and extraction towers, or transported to the middle section of other-stage absorption and enrichment towers. The flow of the composite absorbent 10 can be sequential or reverse, forming a cyclic flow of the composite absorbent 10.

[0040] S5: After a long period of enrichment 14 After the absorption-exchange reaction of the CO2 gas and the composite absorption liquid, a high abundance of CO2 is obtained in the last stage of enrichment and desorption kettle. 14 C of CO2 gas, part of this gas returns to the last stage absorption enrichment tower, and part of it is used as product 14 CO2 gas is extracted and discharged from the top of the first-stage absorption and extraction tower 1 12 CO2 gas.

[0041] S1 contains 14 The intake volume of the CO2 raw material gas 9 of C is 2L / h~20000L / h, preferably 100L / h~1000L / h.

[0042] In the above method, the temperature in each stage of the absorption and extraction tower and the absorption and enrichment tower is 10°C to 40°C, preferably 15°C to 25°C, and the pressure in each stage of the absorption and extraction tower and the absorption and enrichment tower is 0 to 0.15 MPa, preferably 0.1 MPa.

[0043] In S1 , the feed concentration of the composite absorbent 10 is 0.01 mol / L to 5 mol / L, preferably 1 mol / L to 2 mol / L.

[0044] Preferably, the process flow of the composite absorbent 10 does not follow the cascade sequence, but rather a jump mixed flow process with a large concentration difference is selected.

[0045] By continuously introducing CO2 raw gas 9, continuous production of high abundance can be achieved 14 C isotope products.

[0046] Example 1

[0047] See also Figure 2 This embodiment is a separation 14 A method for continuous production of C isotopes, comprising:

[0048] S1: The composite absorbent 10 is sent to the absorption and extraction towers and the absorption and enrichment towers at each level through the liquid phase feed pump 11, and the liquid containing 14 The CO2 raw gas 9 of C, the CO2 raw gas 9 reaches the absorption section of the first absorption and extraction tower 1 through various absorption and extraction towers, and undergoes absorption reaction with the composite absorbent 10 flowing in the tower in the reverse direction. The composite absorption liquid that has absorbed the CO2 raw gas 9 undergoes exchange reaction with the countercurrent CO2 raw gas 9 in the extraction section of the first absorption and extraction tower 1. 14 C is enriched in the liquid phase, 12 C is enriched in the gas phase.

[0049] S2: Enriched 14 The composite absorption liquid of C enters the first-stage extraction and analysis kettle 5, where it is heated and decomposed into 14 C of CO2 gas and composite absorbent 10, which is enriched 14 The CO2 in C enters the middle section of the next absorption and extraction tower, and repeats the process of the first-level absorption and extraction tower 1 and the extraction and desorption kettle until the last level of extraction and desorption kettle. 14 The CO2 gas of C enters the middle section of the first-stage absorption and enrichment tower 2, and begins the absorption-exchange reaction process of the enrichment section.

[0050] S3: In the enrichment tower process, each stage of enrichment and decomposition kettle top enrichment 14 The CO2 gas from C enters the middle section of the next level absorption and enrichment tower and is enriched. 14 C of CO2 gas and composite absorption liquid repeated absorption-exchange reaction process.

[0051] S4: The composite absorbent 10 heated and decomposed by the first-stage extraction and decomposition kettle 5 is transported to the top inlet of the second-stage absorption and enrichment tower by a liquid transfer pump. The decomposed composite absorbent 10 in the second-stage enrichment and decomposition kettle 7 is transported to the top inlet of the first-stage absorption and enrichment tower by a liquid phase transfer pump 11. The composite absorbent 10 in the first-stage enrichment and decomposition kettle is transported to the top inlet of the tertiary absorption and enrichment tower 4 by a liquid phase transfer pump 11. The tertiary enrichment and decomposition kettle 8 is transported to the top inlet of the first-stage absorption and extraction tower 1 by a liquid phase transfer pump 11, thereby forming a circulating flow of the composite absorbent 10.

[0052] S5: After a long period of enrichment 14 After the absorption-exchange reaction between the CO2 gas and the composite absorption liquid, the high-abundance CO2 is discharged from the top of the three-stage enrichment and desorption kettle 8. 14 C of CO2 gas, part of this gas returns to the third-stage absorption enrichment tower 4 tower kettle, part of it is used as product 14 CO2 gas is extracted. On the other side, it is discharged at the top of the first-level absorption and extraction tower. 12 CO2 gas.

[0053] In this embodiment, a stream containing 14 The rate of CO2 raw material of C is 2L / h~20000L / h, preferably 100L / h~1000L / h. At this preferred rate, all baffle towers have good gas-liquid flow performance and high gas-liquid exchange efficiency.

[0054] In this embodiment, the temperature in each stage of the absorption and extraction tower and the absorption and enrichment tower is 10°C~40°C, preferably 15°C~25°C. Under this preferred temperature condition, the reaction process of each stage of the absorption and extraction tower and the absorption and enrichment tower is the most stable, and the reaction rate is faster. There is no need to perform heat exchange treatment on each tower, and the energy consumption is the lowest. The pressure in each stage of the absorption and extraction tower and the absorption and enrichment tower is 0~0.15MPa, preferably 0.1MPa.

[0055] In this embodiment, the feed concentration of the composite absorbent 10 is 0.01 mol / L~5 mol / L, preferably 1 mol / L~2 mol / L. Under this preferred feed concentration condition, the CO2 gas in each tower is absorbed more completely and the gas-liquid exchange efficiency is higher.

[0056] Example 2

[0057] This embodiment provides a separation 14 The continuous production device of C isotope is used to implement the method described in Example 1. Figure 2 The device includes a first-level absorption and extraction tower 1, a first-level absorption and enrichment tower 2, a second-level absorption and enrichment tower 3, a third-level absorption and enrichment tower 4, a first-level extraction and decomposition kettle 5, a first-level enrichment and decomposition kettle 6, a second-level enrichment and decomposition kettle 7, and a third-level enrichment and decomposition kettle 8.

[0058] The first-level absorption and extraction tower 1 is connected to the first-level extraction and decomposition kettle 5 and the first-level absorption and enrichment tower 2, the first-level extraction and decomposition kettle 5 is also connected to the first-level absorption and enrichment tower 2 and the second-level absorption and enrichment tower 3, the first-level absorption and enrichment tower 2 is also connected to the second-level absorption and enrichment tower 3 and the second-level enrichment and decomposition kettle 7, the first-level enrichment and decomposition kettle 6 is also connected to the second-level absorption and enrichment tower 3 and the tertiary absorption and enrichment tower 4, the second-level absorption and enrichment tower 3 is also connected to the second-level enrichment and decomposition kettle 7 and the tertiary absorption and enrichment tower 4, the second-level enrichment and decomposition kettle 7 is also connected to the tertiary absorption and enrichment tower 4, the tertiary absorption and enrichment tower 4 is also connected to the tertiary enrichment and decomposition kettle 8, and the tertiary enrichment and decomposition kettle 8 is also connected to the first-level absorption and extraction tower 1.

[0059] Specifically, a liquid-phase transfer pump 11 is provided on the pipeline connecting the first-stage extraction and decomposition kettle 5 and the second-stage absorption and enrichment tower 3, a liquid-phase transfer pump 11 is provided on the pipeline connecting the first-stage enrichment and decomposition kettle 6 and the third-stage absorption and enrichment tower 4, a liquid-phase transfer pump 11 is provided on the pipeline connecting the second-stage enrichment and decomposition kettle 7 and the first-stage absorption and enrichment tower 2, and a liquid-phase transfer pump 11 is provided on the pipeline connecting the third-stage enrichment and decomposition kettle 8 and the first-stage absorption and extraction tower 1.

[0060] The upper portion of the primary absorption and extraction tower 1 is connected to a liquid phase feed pump 11 via a pipeline, and the liquid phase feed pump 11 is connected to the lower portion of the tertiary enrichment and desorption kettle 8 via a pipeline. The lower portion of the primary absorption and extraction tower 1 is connected to the upper portion of the primary extraction and desorption kettle 5 via a pipeline, and the lower portion of the primary absorption and extraction tower 1 is connected to the upper portion of the primary absorption and enrichment tower 2 via a pipeline.

[0061] The upper part of the first-stage extraction and decomposition kettle 5 is connected to the middle part of the first-stage absorption and enrichment tower 2 through a pipeline, the lower part of the first-stage extraction and decomposition kettle 5 is connected to the liquid phase feed pump 11 through a pipeline, and the liquid phase feed pump 11 is connected to the upper part of the second-stage absorption and enrichment tower 3 through a pipeline.

[0062] The upper part of the first-stage absorption and enrichment tower 2 is connected to the liquid phase feed pump 11 through a pipeline, the liquid phase feed pump 11 is connected to the lower part of the second-stage enrichment and desorption kettle 7 through a pipeline, and the lower part of the first-stage absorption and enrichment tower 2 is connected to the upper part of the second-stage absorption and enrichment tower 3 through a pipeline.

[0063] The upper part of the first-stage enrichment and desorption kettle 6 is connected to the upper part of the second-stage absorption and enrichment tower 3 through a pipeline, the lower part of the first-stage enrichment and desorption kettle 6 is connected to the liquid phase feed pump 11 through a pipeline, and the liquid phase feed pump 11 is connected to the upper part of the third-stage absorption and enrichment tower 4 through a pipeline.

[0064] The lower part of the secondary absorption and enrichment tower 3 is connected to the upper part of the secondary enrichment and desorption kettle 7 through a pipeline, and the lower part of the secondary absorption and enrichment tower 3 is connected to the upper part of the tertiary absorption and enrichment tower 4 through a pipeline.

[0065] The upper part of the secondary enrichment and desorption kettle 7 is connected to the middle part of the tertiary absorption and enrichment tower 4 through a pipeline. The lower part of the tertiary absorption and enrichment tower 4 is connected to the upper part of the tertiary enrichment and desorption kettle 8 through a pipeline, and the lower part of the tertiary enrichment and desorption kettle 8 is connected to the upper part of the primary absorption and extraction tower 1 through a pipeline.

[0066] Example 3

[0067] This embodiment adopts a separation process of a two-stage absorption and extraction tower and a five-stage absorption and enrichment tower.

[0068] The composite absorbent 10 fed into the absorption and extraction tower is a mixed solution of diethanolamine and ethanol, with a diethanolamine concentration of 1 mol / L and containing 14 The C isotope CO2 raw gas is introduced into the first-stage absorption and enrichment tower 1 at a rate of 120 L / h at a height of 5 m. 14 The abundance of C is 1.1%. The temperature in each absorption and extraction tower and absorption and enrichment tower is 25℃ and the pressure is 0.1MPa. The CO2 raw gas 9 undergoes absorption-exchange reaction with the composite absorbent 10 flowing from the top of the tower in the first absorption and extraction tower 1. After passing through the second absorption and extraction tower, 14 The C isotope is gradually exchanged into the composite absorption liquid.

[0069] Enriched 14 The composite absorption liquid of C isotope is heated and decomposed into enriched 14 The C isotope CO2 gas and composite absorbent 10, the composite absorbent 10 of the first extraction and analysis kettle 5 is transported to the top of the second absorption and extraction tower for reflux, and the composite absorbent of the second extraction and analysis kettle is transported to the top of the first absorption and extraction tower 1 for reflux. 14 The CO2 gas with C isotope enters the middle section of the first-stage absorption and enrichment tower.

[0070] In the enrichment section, 14 The composite absorption liquid of C isotope is heated and decomposed into enriched 14 C isotope CO2 gas and composite absorbent 10, each level of desorption kettle enrichment 14 The C isotope CO2 gas flows into the middle of the next stage absorption and enrichment tower.

[0071] The composite absorbent 10 of the first-stage enrichment and desorption kettle 6 is sent to the top of the third-stage absorption and enrichment tower 4 for reflux by the liquid-phase feed pump 11, the composite absorbent 10 of the third-stage enrichment and desorption kettle 8 is sent to the top of the fifth-stage absorption and enrichment tower for reflux by the liquid-phase feed pump 11, the composite absorbent 10 of the fifth-stage enrichment and desorption kettle is sent to the top of the second-stage absorption and enrichment tower 3 for reflux by the liquid-phase feed pump 11, the composite absorbent 10 of the second-stage enrichment and desorption kettle 7 is sent to the top of the fourth-stage absorption and enrichment tower for reflux by the liquid-phase feed pump 11, and the composite absorbent 10 of the fourth-stage enrichment and desorption kettle is sent to the top of the first-stage absorption and enrichment tower 6 for reflux by the liquid-phase feed pump 11.

[0072] Finally, CO2 gas is discharged from the top of the first-stage absorption and extraction tower 1. 14 The abundance of C isotope is 0.011%, the gas flow rate is 119.5L / h, and the CO2 gas discharged from the top of the five-stage enrichment and desorption reactor is 14 The abundance of the C isotope is 85%, and the gas flow rate is 0.5 L / h.

[0073] It should be noted that the enrichment of the extracted segment 14 C composite absorption liquid is used for absorption and extraction 14 The composite absorption liquid of C, the enrichment section is enriched 14 C composite absorption liquid is used for absorption and enrichment 14 C's composite absorption liquid.

[0074] Example 4

[0075] This embodiment adopts a separation process of a first-stage absorption and extraction tower and a third-stage absorption and enrichment tower.

[0076] The composite absorbent 10 fed into the absorption and extraction tower is a mixed solution of diethanolamine and ethanol, with a diethanolamine concentration of 1 mol / L and containing 14 The C isotope CO2 raw gas 9 is introduced into the first-stage absorption and enrichment tower at 10m at a rate of 600L / h. 14 The abundance of C is 1.1%, the temperature in each level of absorption and extraction tower and absorption and enrichment tower is 20°C, and the pressure is 0.14 MPa.

[0077] The CO2 raw gas 9 flows into the primary absorption and extraction tower 1 and undergoes absorption-exchange reaction with the composite absorbent flowing in the tower in the reverse direction. 14 C isotope enrichment in the liquid phase, 12 The C isotope is enriched in the gas phase. The composite absorption liquid is decomposed into enriched 14 C of CO2 gas and composite absorption liquid, which is enriched 14 The CO2 in C enters the middle section of the next-stage absorption and enrichment tower, and begins the absorption-exchange reaction process in the enrichment section.

[0078] In the enrichment section, the enriched liquid coming out from the top of each enrichment and decomposition kettle 14 The CO2 gas from C enters the middle section of the next level absorption and enrichment tower and is enriched. 14 The CO2 gas and the composite absorption liquid repeat the absorption-exchange reaction process.

[0079] The composite absorbent 10 heated and decomposed from the first-stage extraction and decomposition kettle 5 is transported by the liquid feed pump to the top inlet of the second-stage absorption and enrichment tower 3 for reflux, the composite absorption liquid from the second-stage enrichment and decomposition kettle 7 is transported by the liquid phase feed pump 11 to the top inlet of the first-stage absorption and enrichment tower 2 for reflux, the composite absorbent 10 from the first-stage enrichment and decomposition kettle 5 is transported by the liquid phase feed pump 11 to the top inlet of the tertiary absorption and enrichment tower 4 for reflux, and the composite absorption liquid from the tertiary enrichment and decomposition kettle 8 is transported by the liquid phase feed pump 11 to the top of the first-stage absorption and extraction tower 1 for reflux, thereby forming a circulating flow of the composite absorbent 10.

[0080] Finally, CO2 gas is discharged from the top of the first-stage absorption and extraction tower 1. 14 The abundance of C isotope is 0.011%, the gas flow rate is 598.4L / h, and the CO2 gas discharged from the top of the three-stage enrichment and desorption reactor is 14 The abundance of the C isotope is 99%, and the gas flow rate is 1.6 L / h.

[0081] The above description is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A separation 14 A method for the continuous production of C isotopes, characterized in that include: S1: Continuously introduce the liquid containing 14 The CO2 raw gas of C enters the first-level absorption and extraction tower and undergoes absorption reaction with the countercurrent composite absorbent. The composite absorbent that has absorbed CO2 continues to undergo exchange reaction with the gas phase CO2. 14 C is enriched in the liquid phase, 12 C is enriched in the gas phase; S2: Absorption and extraction 14 The composite absorption liquid of C enters the first-level extraction and decomposition kettle and is decomposed into enriched 14 C of CO2 gas and composite absorbent, extract 14 The CO2 gas from C enters the first-stage absorption and enrichment tower; S3: enrichment from the top of each level of enrichment and analysis kettle 14 The CO2 gas from C enters the next level absorption and enrichment tower, and is enriched 14 The CO2 gas and composite absorption liquid of C are repeatedly absorbed and exchanged; S4: The composite absorbent heated and decomposed by the first-stage extraction and decomposition kettle is transported to the absorption and extraction towers of each stage or to the absorption and enrichment towers of each stage to circulate the composite absorbent; wherein, the composite absorbent heated and decomposed by the first-stage extraction and decomposition kettle is transported to the top inlet of the second-stage absorption and enrichment tower by a liquid feed pump, the decomposed composite absorbent of the second-stage enrichment and decomposition kettle is transported to the top inlet of the first-stage absorption and enrichment tower by a liquid phase feed pump, the composite absorbent of the first-stage enrichment and decomposition kettle is transported to the top inlet of the tertiary absorption and enrichment tower by a liquid phase feed pump, and the tertiary enrichment and decomposition kettle is transported to the top inlet of the first-stage absorption and extraction tower by a liquid phase feed pump, thereby forming a circulated use of the composite absorbent; S5: After absorption-exchange reaction, it is discharged through the three-stage enrichment and desorption kettle 14 CO2 gas, part of the gas returns to the three-stage absorption and enrichment tower, and part of the gas is used as the product 14 CO2 gas is extracted and discharged through the first-level absorption and extraction tower 12 CO2 gas.

2. Separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that In S1, the composite absorbent flows in a countercurrent direction in the primary absorption and enrichment tower, and the composite absorption liquid that has absorbed the CO2 raw gas undergoes an exchange reaction with the countercurrent CO2 raw gas in the extraction section of the primary absorption and extraction tower.

3. The separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that S1 contains 14 The intake volume of CO2 raw gas of C is 2L / h~20000L / h, and the feed concentration of composite absorbent is 0.01mol / L~5mol / L.

4. The separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that In S2, the first-stage extraction and decomposition kettle is heated and decomposed into enriched 14 C of CO2 gas and composite absorbent, wherein the enriched 14 The CO2 in C enters the middle section of the next absorption and extraction tower, and repeats the process of the first-stage absorption and extraction tower and the extraction and desorption kettle until the last stage of extraction and desorption kettle.

5. The separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that The temperature in each stage of the absorption and extraction tower and each stage of the absorption and enrichment tower is 10°C to 40°C, and the pressure in the tower does not exceed 0.15MPa.

6. The separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that The composite absorbent is a mixed solution of diethanolamine and ethanol, and the concentration of diethanolamine is 1 mol / L.

7. The separation according to claim 1 14 A method for the continuous production of C isotopes, characterized in that The absorption and extraction tower adopts two stages and the absorption and enrichment tower adopts five stages for separation, including: Continuously introduce 14 The CO2 raw gas of C undergoes absorption-exchange reaction with the composite absorbent flowing from the top of the tower in the first absorption and extraction tower, and after passing through the second absorption and extraction tower, 14 The C isotope is gradually exchanged into the composite absorption liquid; Absorption and extraction 14 The composite absorption liquid of C is heated and decomposed into enriched 14 The CO2 gas and composite absorbent of C, the composite absorbent of the first extraction and analysis kettle is transported to the top of the second absorption and extraction tower for reflux, and the composite absorbent of the second extraction and analysis kettle is transported to the top of the first absorption and extraction tower for reflux. After the second extraction and analysis kettle is analyzed, the enrichment 14 The CO2 gas from C enters the middle section of the first-stage absorption and enrichment tower; Absorption enrichment 14 The composite absorption liquid of C is heated and decomposed into enriched 14 C isotope CO2 gas and composite absorbent, enriched in each stage of desorption reactor 14 The C isotope CO2 gas flows into the middle of the next-stage absorption and enrichment tower; the composite absorbent of the first-stage enrichment and desorption kettle is transported to the top of the third-stage absorption and enrichment tower for reflux, the composite absorbent of the third-stage enrichment and desorption kettle is transported to the top of the fifth-stage absorption and enrichment tower for reflux, the composite absorbent of the fifth-stage enrichment and desorption kettle is transported to the top of the second-stage absorption and enrichment tower for reflux, the composite absorbent of the second-stage enrichment and desorption kettle is transported to the top of the fourth-stage absorption and enrichment tower for reflux, and the composite absorbent of the fourth-stage enrichment and desorption kettle is transported to the top of the first-stage absorption and enrichment tower for reflux; Discharged from the top of the five-stage enrichment and desorption kettle 14 CO2 gas is discharged from the first-level absorption and extraction tower 12 CO2 gas.

8. The separation according to claim 7 14 A method for the continuous production of C isotopes, characterized in that contain 14 The CO2 feed gas feed rate of C is 120L / h. 14 The abundance of C is 1.1%, and the temperature in each level of absorption and extraction tower and absorption and enrichment tower is 25°C and the pressure is 0.1 MPa.

9. A separation 14 A continuous production device for C isotopes, which implements the method according to any one of claims 1 to 6, characterized in that: It includes a first-stage absorption and extraction tower, a first-stage absorption and enrichment tower, a second-stage absorption and enrichment tower, a third-stage absorption and enrichment tower, a first-stage extraction and desorption kettle, a first-stage enrichment and desorption kettle, a second-stage enrichment and desorption kettle, and a third-stage enrichment and desorption kettle; The first-level absorption and extraction tower is connected to the first-level extraction and decomposition kettle and the first-level absorption and enrichment tower, the first-level extraction and decomposition kettle is also connected to the first-level absorption and enrichment tower and the second-level absorption and enrichment tower, the first-level absorption and enrichment tower is also connected to the second-level absorption and enrichment tower and the second-level enrichment and decomposition kettle, the first-level enrichment and decomposition kettle is also connected to the second-level absorption and enrichment tower and the tertiary absorption and enrichment tower, the second-level absorption and enrichment tower is also connected to the second-level enrichment and decomposition kettle and the tertiary absorption and enrichment tower, the second-level enrichment and decomposition kettle is also connected to the tertiary absorption and enrichment tower, the tertiary absorption and enrichment tower is also connected to the tertiary enrichment and decomposition kettle, and the tertiary enrichment and decomposition kettle is also connected to the first-level absorption and extraction tower.

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