CN111359440A - Method and system for separating and purifying 14C isotope from waste - Google Patents

Method and system for separating and purifying 14C isotope from waste Download PDF

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Publication number
CN111359440A
CN111359440A CN202010190466.8A CN202010190466A CN111359440A CN 111359440 A CN111359440 A CN 111359440A CN 202010190466 A CN202010190466 A CN 202010190466A CN 111359440 A CN111359440 A CN 111359440A
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tower
exchange
separation
separating
purifying
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徐志红
沈佳宇
双加磊
桂媛
邬伟
徐武双
金志成
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Changshu Zhihe Environmental Technology Co ltd
JIANGSU HUAYI TECHNOLOGY CO LTD
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Changshu Zhihe Environmental Technology Co ltd
JIANGSU HUAYI TECHNOLOGY CO LTD
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D59/00—Separation of different isotopes of the same chemical element
    • B01D59/22—Separation by extracting
    • B01D59/26—Separation by extracting by sorption, i.e. absorption, adsorption, persorption
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
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Abstract

The invention belongs to the technical field of isotope separation and purification, and particularly relates to a method and a system for separating and purifying 14C isotopes from wastes. The method comprises the following steps: 1) and (3) refining a crude product: mixing 14C-CO2The crude product is subjected to two-stage condensation and then is sequentially subjected to evaporation and desublimation to obtain a pure product 14C-CO2(ii) a 2) Isotope separation and enrichment: the pure product 14C-CO obtained in the step 1)2Evaporated and then sent to an exchange column, 14C-CO2With the liquid phase 12C-CO from the top of the exchange column2Effecting exchange in an exchange column; 14C-CO2Discharging from the bottom of the exchange tower, and then feeding into a desorption tower for desorption to obtain an ultra-pure product 14C-CO2. The invention provides a method and a system for recovering 14C from nuclear waste, the method has the advantages of simple process steps, stable raw material source and low cost, and provides a new idea for industrial production of high-purity 14C isotopes. Furthermore, the 14C obtained by the separation system has high purityIt can reach more than 90%.

Description

Method and system for separating and purifying 14C isotope from waste
Technical Field
The invention belongs to the technical field of isotope separation and purification, and particularly relates to a method and a system for separating and purifying 14C isotopes from wastes.
Background
Carbon exists in various isotopes such as 12C, 13C, 14C and the like in nature, and the relative abundance of 12C and 13C is 98.89 percent and 1.11 percent respectively; 14C is only very trace and radioactive, and has a half-life of 5730 years.
As a radioactive isotope, the 14C isotope is a common source tracing index, can be applied to the fields of detection of helicobacter pylori (Hp), ADME (absorption, distribution, metabolism and excretion) research of medicines, other environmental detection and the like, and has wide application.
The natural radioactive carbon isotope (14C) is mainly derived from the reaction of neutrons generated by cosmic rays in the high-rise atmosphere and the stable nitrogen isotope 14N, and the generated 14C is combined with oxygen in the atmosphere to form carbon dioxide (14 CO)2) Enters the lower atmosphere, enters the ocean through sea-gas exchange and vertical mixing, and becomes an inorganic carbon source for life activities (such as assimilation of photosynthesis, chemoautotrophy and the like) of land and marine organisms.
However, the content of 14C in nature is very low, and is only 1.2 × 10-10% of the total weight of the composition. The preparation of 14C in nature is extremely difficult, the input cost of production equipment is high, and the enrichment difficulty is high.
Currently, 14C is produced mainly by irradiating AlN powder target material through a reactor. Such as literature (technical research on preparation of (14) C source material by irradiation of high-purity AlN through Chinese advanced research heap, < annual newspaper of Chinese atomic energy science institute > 2013, period 00). But the productivity is not large, the separation and purification are difficult, and the cost is high. Causing frequent shortages in the market, which in turn leads to high prices for the 14C isotope.
Nuclear power plant reactor fuel produces a large number of fission products during combustion, which produce about 80 radioisotopes. Radioactive elements are still present in high abundance in the waste from nuclear reactors. (Master thesis of dynamics of absorption and accumulation of gaseous 14C by plants.) Nuclear Power plant waste, including waste and waste streams, has 14C nuclide, typically 14C-CH4, 14C-CO2And the like exist in gas forms, the waste is generally generated by a pressurized water reactor in dozens of Ci every year, and the 14C of hundreds of Curie (Ci) is generated in a heavy water reactor every year.
Because of its long half-life and high toxicity, 14C accumulates in the environment causing radiation exposure much greater than noble gases and tritium. At present, the nuclide is mainly directly discharged through effluent, which not only causes radiation hazard to human bodies through various ways, but also causes environmental pollution; but also causes waste of resources.
Therefore, the separation and purification of the 14C isotope from the nuclear reactor waste meets the requirement of green production, and a new way is provided for the preparation of the 14C isotope. And the nuclear reactor has large waste amount and stable supply, so the method is suitable for large-scale industrial production. However, there is no report on this aspect.
Disclosure of Invention
In order to overcome the above problems in the prior art, it is an object of the present invention to provide a method for separating and purifying 14C isotopes from nuclear power plant waste.
Another object of the present invention is to provide a system for separating and purifying 14C isotopes from waste.
In order to achieve the above purpose, the invention provides the following technical scheme:
a method for separating and purifying 14C isotopes from nuclear power plant waste, comprising the steps of:
1) and (3) refining a crude product: mixing 14C-CO2The crude product is sequentially at-20 to 0 DEG CCarrying out two-stage condensation at-78.5 to-170 ℃, and then evaporating at-77 to 0 ℃ and desublimating at-78.5 to-170 ℃ in sequence to obtain a pure product 14C-CO2；
2) Isotope separation and enrichment: the pure product 14C-CO obtained in the step 1)2Evaporated and then sent to an exchange column, 14C-CO2With the liquid phase 12C-CO from the top of the exchange column2Effecting exchange in an exchange column; 14C-CO2Discharging from the bottom of the exchange tower, and then feeding into a desorption tower for desorption to obtain an ultra-pure product 14C-CO2.。
Preferably, the liquid phase 12C-CO in step 2)2Is prepared from organic or inorganic alkali and 12C-CO2In the form of a complex.
Specifically, an organic or inorganic base acts as a catalytic exchange reagent (for ease of representation, denoted by the letter R) to absorb 12CO2The reaction formula of the gas is as follows:
R(l)+12CO2(g)→R-12CO2(l)。
preferably, the organic base is selected from the group consisting of substituted or unsubstituted C1-C20 primary amines R-NH2Substituted or unsubstituted C1-C20 secondary amine R-NH-R ', substituted or unsubstituted C1-C20 tertiary amine (R, R') -N, substituted or unsubstituted C5-C10 nitrogen-containing aromatic ring.
Preferably, the substituted substituent is-Cl, -Br, -F or-OH.
Preferably, in the secondary amine, R or R' is an alkene or an alkane.
Preferably, in the tertiary amine, R, R' is an alkene or an alkane.
Preferably, the nitrogen-containing aromatic ring is pyridine.
Preferably, the solvent of R is substituted or unsubstituted C1-C20 alcohol containing 1-3 hydroxyl groups, substituted or unsubstituted C1-C10 ether, substituted or unsubstituted C1-C10 halohydrocarbon, substituted or unsubstituted C1-C10 ester, substituted or unsubstituted C1-C10 ketone, substituted or unsubstituted C6-C12 phenol, substituted or unsubstituted C1-C10 amine, substituted or unsubstituted C1-C10 alkane, substituted or unsubstituted C1-C10 alkene and substituted or unsubstituted C6-C14 aromatic hydrocarbon.
Preferably, the substituent is-Cl, -Br, -F or-OH.
Preferably with 12C-CO in the liquid phase2When the organic base is used for forming the complex, the concentration of the organic base is 0.001mol/L-10 mol/L.
Preferably, the inorganic base is selected from sodium hydroxide, potassium hydroxide, barium hydroxide or tetrabutylammonium hydroxide.
Preferably with 12C-CO in the liquid phase2When the inorganic base is used for forming the complex, the concentration of the inorganic base is 0.001mol/L-12 mol/L.
For example, the inorganic base is NaOH and the strong base absorbs CO2Will be converted into the corresponding form of carbonate (R) which, after further absorption, is converted into bicarbonate. The reaction formula is as follows:
2NaOH+CO2→Na2CO3+H2O
Na2CO3+CO2+H2O→2NaHCO3。
in the invention, the pure product 14CO obtained in the step 1)2By evaporation into an exchange column, 14C-CO2With 12C-CO2And (3) realizing exchange: under the action of catalytic filler, 14C-CO2With R-12CO in the liquid phase2Fast exchange of R-14CO2Entering a liquid phase, moving to the bottom of the tower, entering an analytical tower, and carrying out the following analytical reaction:
R-12CO2(l)+14CO2(g)→R-14CO2(l)+12CO2(g)。
gas phase CO discharged from the stripper2And the obtained product enters an absorption tower again to exchange again after being absorbed. In the above process, the enriched 14CO2And is discharged from the bottom of the exchange tower.
Preferably, the temperature in the exchange column of step 2) is between 0 ℃ and 100 ℃ and the pressure is between-0.09 MPa and 0.5 MPa.
Further preferably, the temperature is 10-40 ℃ and the pressure is-0.01-0.2 MPa.
Preferably, step 2)14C-CO2With 12C-CO in liquid phase2The exchange is realized under the action of catalytic filler, wherein the material of the catalytic filler is metal or surface oxide and alloy thereofOr one or more of surface oxides, high molecular materials and inorganic materials thereof.
Further preferably, the metal is copper, aluminum, iron, or the like.
Further preferably, the alloy is an alloy material composed of two or more elements of Fe, Cu, Al, Ni, Cr, Mn, and the like.
Further preferably, the polymer material is polypropylene, nylon or a surface-hydroxylated-grafted material thereof.
Further preferably, the inorganic material is a ceramic, glass, or the like.
Preferably, in the raw material nuclear power plant waste of the present invention, 14C-CO2The content of (A) is 0.01-10%; 14C-CH4The content of (A) is 0.01-90%; the content of 14C-CO is 0.01-90%.
Preferably, said 14CO2Evaporating the crude product at-70 deg.C to 0 deg.C after two-stage condensation, desublimating at-78.5 deg.C to-170 deg.C, and repeating the evaporating and desublimating operation for 1-3 times, such as 14CO2The crude product is evaporated at 20 ℃ after sequentially passing through-70 ℃, 90 ℃, 70 ℃ and 90 ℃ and then enters an isotope enrichment device.
Preferably, the 14C-CO of step 1)2The preparation method of the crude product comprises the following steps:
will contain 14C-CO, 14C-CH4Is oxidized by an oxidant to form a gas containing 14C-CO2The oxidant is one or more of permanganate, high chromate, iron oxide, copper oxide, sulfur oxide, phosphorus pentoxide, hydrogen peroxide, ozone, peracetic acid and oxygen.
Preferably, the 14C-CO of the present invention2The crude product was also treated as follows before the two-stage condensation:
1)CO2carrying; introducing CO2Introducing gas into an alkali solution for absorption, wherein the reaction formula is as follows:
such as B (OH)2+14C-CO2→BCO3+H2O
2) To base BCO3Adding acid solution to resolve CO 2.
The reaction formula is as follows: such as BCO3+H2SO4→BSO4+H2O+CO2
As the alkali in the step 1), alkali solution which can form insoluble carbonate, such as Ca (OH) is preferable2、Ba(OH)2Etc. form the form of calcium carbonate or barium carbonate.
The invention also provides a system for separating and purifying 14C isotope from waste, which comprises a gas oxidation system, a primary low-temperature cooling system, a secondary low-temperature cooling system and 14C-CO connected in sequence2A separation and enrichment system is arranged in the separation and enrichment system,
the 14C-CO2The separation and enrichment system comprises 12C-CO2/14C-CO2An exchange tower, a desorption tower and an absorption tower;
the outlet of the secondary cryogenic cooling system is in communication with the 12C-CO2/14C-CO2The air inlet of the exchange tower body is connected with the 12C-CO2/14C-CO2An outlet at the bottom of the exchange tower is connected with an air inlet of a resolving tower body, an air outlet at the bottom of the resolving tower is connected with an air inlet at the bottom of the absorption tower, and an air outlet at the top of the absorption tower is connected with an air inlet at the top of the exchange tower; the gas outlet at the top of the analysis tower is connected with the gas inlet at the bottom of the exchange tower; and the gas outlet at the top of the exchange tower is connected with the gas inlet of the absorption tower body.
Preferably, the primary cryogenic cooling system comprises a-20 to 0 ℃ cryotrap and a-78.5 to-170 ℃ cryotrap connected in series.
Preferably, the secondary cryogenic cooling system comprises a-77 to 0 ℃ cryotrap, a-78.5 to-170 ℃ cryotrap and a-77 to 0 ℃ cryotrap connected in series. CO cooled by primary low-temperature cooling system2After entering a secondary low-temperature cooling system, the mixture is evaporated and condensed, and finally evaporated and enters the next process in a gas form.
Preferably, the gas oxidation system is an oxidation bed.
Preferably, an absorption tank is further arranged between the gas oxidation system and the primary low-temperature cooling system, and the absorption tank is connected with the alkali liquor adding device and the acid liquor adding device.
Preferably, an alkaline adsorption resin is further arranged between the gas oxidation system and the primary low-temperature cooling system, and a heating device is arranged outside the adsorption resin. Preferably, the temperature of the heating device is raised to 30-200 ℃.
Firstly, gas enters into alkaline adsorption resin for adsorption, and then CO is heated by raising the temperature to ensure that2And (6) analyzing.
Compared with the prior art, the invention has the following beneficial effects:
(1) the invention provides a method for recovering 14C from nuclear waste, which has the advantages of simple process steps, stable raw material source and low cost, and provides a new idea for industrial production of high-purity 14C isotopes.
(2) The 14C prepared by the separation and purification method provided by the invention has high purity which can reach more than 90%.
(3) The invention provides a separation and purification system for recovering 14C from waste of a nuclear power station, which has a simple structure and low cost.
(4) The purity of 14C prepared by the separation and purification system provided by the invention is high and can reach more than 90%.
Drawings
FIG. 1 shows pure 14C-CO2Schematic flow diagram for enrichment;
FIG. 2 shows the preparation of pure 14C-CO from the starting materials as provided in example 12A flow chart of (1);
fig. 3 is a schematic diagram of the 14C separation and purification system provided in example 4.
Detailed Description
The method of the present invention is described below with reference to specific examples to make it easier to understand and understand the technical solution of the present invention, but the present invention is not limited thereto. The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
Example 1
As shown in fig. 1-2, a method for separating and purifying 14C isotopes from nuclear power plant waste comprises the following steps:
S1 14C-CO2the preparation of (1): 100L of the mixture contains 20 percent of 14C-CO and 70 percent of 14C-CH4Grade 10% 14C-CO2Introducing the mixed gas into KMnO4In solution, the passing speed is 100L/h, KMnO4The concentration of the solution is 1M, the volume is 100L, and the temperature is 70 ℃; obtaining 14CO2The total amount of crude products is 99.9L;
S2 CO2solid load
100L14CO2Crude product, with 100L/h CO210L of 2M Ba (OH) was introduced2In the solution, the temperature is room temperature; to obtain BaCO3Solid, filtering and drying, and totaling 880 g;
S3 CO2analysis of
200g of BaCO3Adding 2L of 1M sulfuric acid solution in batches, reacting at room temperature, allowing the generated gas to pass through a 0 ℃ low-temperature cold trap, introducing into a-90 ℃ low-temperature cold trap, and discharging the redundant gas; a total of 86g of dry ice solids were obtained;
S4 CO2purification of
Slowly heating 88g of the preliminarily obtained dry ice solid to-70 ℃, staying for 2h, and desublimating through a receiving bottle condensed at-90 ℃; slowly heating the receiving bottle at-90 deg.C to-70 deg.C, continuously sublimating the product, and desublimating with the subsequent receiving bottle at-90 deg.C to obtain pure 14CO2Material, 87g in total;
S5 14CO2separating and enriching
Pure product of 14CO2Evaporating to 50 deg.C, separating and enriching with 100mm diameter exchange tower, feeding into exchange tower, and introducing into 14C-CO exchange tower2With R-12CO in the liquid phase2Fast exchange of R-14CO2Entering a liquid phase, moving to the bottom of the tower, entering an analytical tower, and carrying out the following analysis reaction:
R-12CO2(l)+14CO2(g)→R-14CO2(l)+12CO2(g)。
gas phase CO discharged from the stripper2And the obtained product enters an absorption tower again to exchange again after being absorbed. In the above process, the enriched 14CO2And is discharged from the bottom of the exchange tower.
Wherein, the chemical catalytic exchange reagent R adopted in the exchange tower is a methanol solution of pyridine with the concentration of 1 mol/L; the catalytic filler in the exchange tower is aluminum;
the pressure in the tower is 0.2MPa, and the temperature is 50 ℃;
in this example, 14CO produced2The purity of (2) was 95%.
Example 2
A method for separating and purifying 14C isotopes from nuclear power plant waste, comprising the steps of:
S1 14C-CO2the preparation of (1): 100L of the mixture is mixed with 100L of 90 percent of 14C-CO and 9.99 percent of 14C-CH4Grade 0.01% 14C-CO2Introducing KMnO4In solution, the passing speed is 100L/h, KMnO4The concentration of the solution is 2M, the volume is 100L, and the temperature is 80 ℃; obtaining 14CO2The total amount of the crude products is 95.0L;
s2 preparation of 14CO from S12The crude gas firstly passes through a low-temperature cold trap at the temperature of minus 20 ℃, then is introduced into a low-temperature cold trap at the temperature of minus 170 ℃, and redundant gas is discharged;
S3 CO2purification of
Slowly heating the preliminarily obtained dry ice solid to 0 ℃, staying for 2 hours, and desublimating through a receiving bottle condensed at-170 ℃; slowly heating to-70 deg.C, continuously sublimating the product, and desublimating with subsequent-90 deg.C receiving bottle to obtain pure 14CO2A substance;
S4 14CO2separation of
Pure product of 14CO2Separating and enriching by adopting an exchange tower with the diameter of 100mm, wherein a chemical catalytic exchange reagent R adopted in the exchange tower is a methanol solution of pyridine, and the concentration is 1 mol/L; the catalytic filler in the exchange tower is macromolecular polypropylene.
The pressure in the tower is 0.2MPa, and the temperature is 30 ℃;
in this example, 14CO produced2The purity of (A) is 98%
Example 3
A method for separating and purifying 14C isotopes from nuclear power plant waste, comprising the steps of:
S1 14C-CO2the preparation of (1): 100L of KMnO4 solution containing 0.01% 14C-CO and 90% 14C-CH4 and 9.99% 14C-CO2 was added into 100L/h of KMnO4The concentration of the solution is 2M, the volume is 100L, and the temperature is 80 ℃; obtaining 14CO2The total amount of the crude products is 97.0L;
s2 preparation of 14CO from S12The crude gas firstly passes through a low-temperature cold trap at the temperature of minus 20 ℃, then is introduced into a low-temperature cold trap at the temperature of minus 170 ℃, and redundant gas is discharged;
S3 CO2purification of
Slowly heating the preliminarily obtained dry ice solid to 0 ℃, staying for 2 hours, and desublimating through a receiving bottle condensed at-78.5 ℃; then slowly heating the receiving bottle at-78.5 ℃ to-0 ℃, continuously sublimating the product, and sublimating by using the subsequent receiving bottle at-78.5 ℃ to obtain a pure product 14CO2A substance;
S4 14CO2separation of
Pure product of 14CO2Separating and enriching by adopting an exchange tower with the diameter of 100mm, wherein a chemical catalytic exchange reagent R adopted in the exchange tower is an aqueous solution of sodium hydroxide, and the concentration is 1 mol/L; the catalytic filler in the exchange tower is ferric oxide.
The pressure in the tower is 0.1MPa, and the temperature is 100 ℃;
in this example, 14CO produced2The purity of (2) was 91%.
Example 4
As shown in fig. 3, a separation and purification system for recovering 14C isotope from nuclear power plant waste comprises a gas oxidation system, a primary cryogenic cooling system, a secondary cryogenic cooling system and 14C-CO connected in sequence2A separation and enrichment system is arranged in the separation and enrichment system,
the 14C-CO2The separation and enrichment system comprises 12C-CO2/14C-CO2An exchange tower, a desorption tower and an absorption tower;
the outlet of the secondary cryogenic cooling system is in communication with the 12C-CO2/14C-CO2The air inlet of the exchange tower body is connected with the 12C-CO2/14C-CO2The outlet at the bottom of the exchange tower is connected with the air inlet of the analysis tower body, and the air outlet at the bottom of the analysis tower is connected with the air inlet of the analysis tower bodyThe gas inlet at the bottom of the absorption tower is connected, and the gas outlet at the top of the absorption tower is connected with the gas inlet at the top of the exchange tower; the gas outlet at the top of the analysis tower is connected with the gas inlet at the bottom of the exchange tower; the gas outlet at the top of the exchange tower is connected with the gas inlet of the absorption tower body;
in this embodiment, the primary cryogenic cooling system comprises a cryogenic trap at-20 to 0 ℃ and a cryogenic trap at-78.5 to-170 ℃ connected in series. The mixed gas is condensed by a low-temperature cold trap at the temperature of between 20 ℃ below zero and 0 ℃ to remove water and SO2And components with boiling point above-20 deg.C.
The mixed gas is treated by adopting a low-temperature cold trap at the temperature of between 78.5 ℃ below zero and 170 ℃ below zero, and CO is mainly used2The gas is desublimated into dry ice; the excess gas being ordinary O2，N2And the like, and can be directly discharged.
The secondary low-temperature cooling system comprises a-77-0 ℃ low-temperature cold trap, a-78.5-170 ℃ low-temperature cold trap and a-77-0 ℃ low-temperature cold trap which are sequentially connected. Under the action of a secondary low-temperature cooling system, the desublimated dry ice is heated and evaporated at the temperature of between-77 and 0 ℃ (such as-70 ℃), and nonvolatile components are directly discarded; purification of the gas can then be achieved by equipment desublimation at-78.5 to-170 ℃ (e.g., -80 ℃) and finally by one to multiple back and forth evaporations and desublimation at-77 to 0 ℃ (e.g., -70 ℃).
Pure product 14CO discharged from secondary low-temperature cooling system2And (4) entering a separation and enrichment system for further separation and enrichment to realize purification. Pure product of 14CO2The process of achieving further purification in the separation and enrichment system is as follows:
first, the pure product 14CO2From 12C-CO2/14C-CO2The air inlet of the exchange tower body enters the exchange tower,
under the action of catalytic packing in an exchange column, 14C-CO2With liquid phase R-12CO from the absorption column2Rapid exchange of exchanged R-14CO2Moving to the bottom of the tower, entering into a desorption tower, and desorbing the 14CO2The obtained product enters the exchange tower again, and the resolved liquid absorbent enters the absorption tower to absorb the 12C-CO at the top of the exchange tower2Then enters the exchange tower again for carrying outAnd then switched again. Ultra-pure 14C-CO after multiple exchanges2And is discharged from the tower body exhaust port of the exchange tower.
The 14C in the waste of the nuclear power station is separated and purified by the embodiment, and 14C-CO is detected2The purity of (A) is more than 90%.
Finally, it should be noted that the above-mentioned contents are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, and that the simple modifications or equivalent substitutions of the technical solutions of the present invention by those of ordinary skill in the art can be made without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A method for separating and purifying 14C isotopes from wastes of a nuclear power plant is characterized by comprising the following steps:
1) and (3) refining a crude product: mixing 14C-CO2The crude product is sequentially subjected to two-stage condensation at-20 to 0 ℃ and-78.5 to-170 ℃, and then is sequentially evaporated at-77 to 0 ℃ and desublimated at-78.5 to-170 ℃ to obtain a pure product 14C-CO2；
2) Isotope separation and enrichment: the pure product 14C-CO obtained in the step 1)2Evaporated and then sent to an exchange column, 14C-CO2With the liquid phase 12C-CO from the top of the exchange column2Effecting exchange in an exchange column; 14C-CO2Discharging from the bottom of the exchange tower, and then feeding into a desorption tower for desorption to obtain an ultra-pure product 14C-CO2.。
2. The method for separating and purifying 14C isotopes from nuclear power plant waste as claimed in claim 1, wherein the liquid phase 12C-CO in step 2) is 12C-CO2Is prepared from organic or inorganic alkali and 12C-CO2In the form of a complex.
3. The method for separating and purifying 14C isotopes from nuclear power plant waste as claimed in claim 2, wherein 12C-CO is in liquid phase2The compound is formed by using organic base, and the concentration of the organic base is 0.001mol/L-10 mol/L.
4. According to claim 2The method for separating and purifying 14C isotope from the nuclear power plant waste is characterized in that the isotope is separated from 12C-CO in liquid phase2The inorganic base is used for forming the compound, and the concentration of the inorganic base is 0.001mol/L-12 mol/L.
5. The method for separating and purifying 14C isotopes from nuclear power plant waste as claimed in any one of claims 1 to 4, wherein the temperature in the exchange column of step 2) is 0-100 ℃ and the pressure is-0.09-0.5 MPa.
6. Method for separating and purifying 14C isotopes from nuclear power plant waste according to any of claims 1 to 4, characterised in that step 2)14C-CO2With 12C-CO in liquid phase2The exchange is realized under the action of catalytic filler, wherein the material of the catalytic filler is one or more of metal or surface oxide thereof, alloy or surface oxide thereof, high molecular material and inorganic material.
7. Method for separating and purifying 14C isotopes from nuclear power plant waste according to any one of claims 1 to 4, characterised in that 14C-CO in the nuclear power plant waste2The content of (A) is 0.01-10%; 14C-CH4The content of (A) is 0.01-90%; the content of 14C-CO is 0.01-90%.
8. A14C isotope separation and purification system is characterized by comprising a gas oxidation system, a primary low-temperature cooling system, a secondary low-temperature cooling system and a 14C-CO isotope separation and purification system which are sequentially connected2A separation and enrichment system is arranged in the separation and enrichment system,
the 14C-CO2The separation and enrichment system comprises 12C-CO2/14C-CO2An exchange tower, a desorption tower and an absorption tower;
the outlet of the secondary cryogenic cooling system is in communication with the 12C-CO2/14C-CO2The air inlet of the exchange tower body is connected with the 12C-CO2/14C-CO2The outlet at the bottom of the exchange tower is connected with the air inlet of the analysis tower body, the liquid outlet at the bottom of the analysis tower is connected with the liquid inlet at the bottom of the absorption tower, and the absorption towerA liquid outlet at the top of the tower is connected with a liquid inlet at the top of the exchange tower; the gas outlet at the top of the analysis tower is connected with the gas inlet at the bottom of the exchange tower; and the gas outlet at the top of the exchange tower is connected with the gas inlet of the absorption tower body.
9. The system for separation and purification of a 14C isotope according to claim 8, wherein said primary cryogenic cooling system comprises a-20 to 0 ℃ cryogenic trap and a-78.5 to-170 ℃ cryogenic trap connected in series.
10. The system for separation and purification of 14C isotope according to claim 8, wherein said secondary cryogenic cooling system comprises a-77 to 0 ℃ cryogenic trap, a-78.5 to-170 ℃ cryogenic trap and a-77 to 0 ℃ cryogenic trap connected in series.
CN202010190466.8A 2020-03-18 2020-03-18 Method and system for separating and purifying 14C isotope from waste Pending CN111359440A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113270215A (en) * 2021-05-18 2021-08-17 清华大学 Liquid effluent from nuclear power plants14C automatic pretreatment device and treatment method
CN113979461A (en) * 2021-08-30 2022-01-28 中国船舶重工集团公司第七一八研究所 Method and system for recovering 14C in 14C-containing waste gas
CN114210205A (en) * 2021-09-16 2022-03-22 苏州思萃同位素技术研究所有限公司 Separation device and separation method for carbon-14 isotope
CN116002686A (en) * 2022-12-30 2023-04-25 无锡贝塔医药科技有限公司 A be used for separating to contain 14 In C target material 14 C method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113270215A (en) * 2021-05-18 2021-08-17 清华大学 Liquid effluent from nuclear power plants14C automatic pretreatment device and treatment method
CN113270215B (en) * 2021-05-18 2022-12-09 清华大学 Liquid effluents from nuclear power plants 14 C automatic pretreatment device and treatment method
CN113979461A (en) * 2021-08-30 2022-01-28 中国船舶重工集团公司第七一八研究所 Method and system for recovering 14C in 14C-containing waste gas
CN114210205A (en) * 2021-09-16 2022-03-22 苏州思萃同位素技术研究所有限公司 Separation device and separation method for carbon-14 isotope
CN116002686A (en) * 2022-12-30 2023-04-25 无锡贝塔医药科技有限公司 A be used for separating to contain 14 In C target material 14 C method

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