KR102254271B1 - Recycling process of a used impregnated adsorbents - Google Patents

Abstract

The present invention relates to a method for recycling a waste impregnated adsorbent which simultaneously removes radioactive material and an impregnated material from the waste impregnated adsorbent used for adsorption of the radioactive material generated in an air purification system such as a nuclear power plant, and also by removing only the radioactive material and the impregnated material without adding a change in the physical properties of the waste impregnated adsorbent, it is possible to reuse by recycling the adsorbent.

Description

Recycling process of a used impregnated adsorbents

The present invention is to provide a method of regenerating the waste impregnated adsorbent by simultaneously removing the adsorbed radioactive material and the impregnated material so that the waste impregnated adsorbent used in a nuclear power facility can be recycled.

The present invention is an adsorbent in which an impregnated material such as TEDA (Triethylenediamine) used to adsorb and remove radioactive iodine in a nuclear facility, that is, a waste impregnated adsorbent is impregnated from the waste impregnated adsorbent instead of classified and disposed of as radioactive solid waste. The present invention relates to a method of regenerating the waste impregnation adsorbent so that it can be reused by simultaneously removing the material and the radioactive material adsorbed on the impregnated material.

Impregnated adsorbents used in nuclear facilities refer to adsorbents that have increased chemical activity by adsorbing impregnated substances on the pore walls of the adsorbent in order to improve the adsorption efficiency of certain harmful substances that are difficult to remove with general adsorbents or to extend the use period of the adsorption tower. .

In other words, by physical adsorption by a general adsorbent, the adsorption capacity of radioactive iodine is large, but it is easily desorbed when the high humidity atmosphere or temperature rises. To overcome this problem, triethylenediamine (hereinafter, TEDA) or An impregnated adsorbent to which an impregnated material such as potassium iodide (hereinafter, referred to as KI) is adsorbed is used.

These impregnated adsorbents are replaced with new adsorbents when their adsorption performance decreases after a certain period of use, and the waste impregnated adsorbents generated at this time are classified into radioactive wastes including radioactive iodine, radioactive xenon, krypton, tritium, and radiocarbons. It is temporarily stored within. After storage for a certain period of time, radioactive iodine or radioactive xenon with a short half-life almost disappears, but contains a significant amount of tritium with a relatively long half-life (half-life of 12.3 years) or radiocarbon with a very long half-life (half-life, 5,730 years). .

Looking at the prior art for removing tritium and radiocarbon adsorbed on such a waste adsorbent, Korean Patent Registration No. 10-2001232 discloses the carbon compound by decompressing the waste activated carbon adsorbed with a carbon compound containing radiocarbon in a reactor. Detaching (step 1); Adsorbing oxygen to the waste activated carbon in the reactor (step 2); Performing primary degassing on the waste activated carbon in the reactor (step 3); Raising the temperature in the reactor (step 4); And performing secondary degassing on the waste activated carbon in the reactor (step 5). A method for removing radioactive materials in the waste activated carbon is disclosed. Korean Patent Publication No. 10-0376080 (2003) In 03. 15.), instead of disposing of the used impregnated activated carbon as radioactive solid waste, use an extraction solvent to extract and remove the impregnated material and adsorbed radioactive organic iodine from the used impregnated activated carbon, and then remove TEDA/KI. Disclosed is an apparatus and method for regenerating impregnated activated carbon which is re-imposed and reused in an exhaust treatment process for adsorbing radioactive organic iodine in a nuclear facility.

In other words, the most commonly used method of regeneration of waste impregnated adsorbents currently is to give considerable heat treatment time in a heating furnace, heat and sinter at a high temperature of about 1,000°C, and blow strong wind or steam to remove contaminants in the micropores of activated carbon. There is a method of removing or impregnating contaminated waste activated carbon in strong hydrochloric acid and washing dozens of times with a large amount of distilled water.

However, since the above method requires strong wind and water vapor to be injected, it has to be manufactured by complex special heating, and as it is activated at high temperatures, the amount of fuel used is high, so the regeneration cost is high, and the material adsorbed on the adsorbent is irreversible. In the case of adsorption, it is reported that the practicality is low because it is difficult to decompose or desorb the material.

In addition, the regeneration method of the waste impregnated adsorbent using strong hydrochloric acid has low regeneration efficiency, and there is a problem of environmental pollution as well as regeneration cost as a large amount of acid is used. In addition, according to the treatment method of the waste impregnated adsorbent according to the prior art, pores of the waste adsorbent are destroyed during treatment, so that reuse as an adsorbent becomes impossible.

The present invention is to provide a method of simultaneously removing radioactive materials and impregnated materials from a waste impregnated adsorbent used for adsorption of radioactive materials generated in an air purification system in a nuclear power plant or the like. In addition, it is to provide a reusable regeneration method of the adsorbent by removing only the radioactive material and the impregnated material without changing the physical properties of the waste impregnated adsorbent. However, the technical problem to be achieved by the present invention is not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problem, the ^{method of regenerating the waste impregnation adsorbent in which carbon compounds containing radiocarbon (14} C) and tritium ( ³ H) are adsorbed according to the present invention is: i) waste impregnation used in the powder reactor (10). A first step of filling an adsorbent; Ⅱ) a second step for vaporizing the carbon compound, and tritium ⁽³ H) is adsorbed impregnated material comprising the powder reactor 10. The radiocarbon ⁽¹⁴ C the temperature was raised to 150 ~ 300 ℃) from the pyecheom complex adsorbent ; Iii) a third step of discharging the impregnated material vaporized in the second step by applying a vacuum to the powder reactor 10; Iv) The powder reactor 10 is heated to 300 ~ 600 °C, and an inert gas containing 3 ~ 10% by volume of oxygen is added to maintain the internal pressure of the powder reactor 10 at 3 bar. containing radioactive carbon ⁽¹⁴ C) the residual carbon compounds and tritium fourth step of ⁽³ H) vaporizing the impregnated adsorbent material; V) a fifth step of discharging the impregnated material vaporized in the fourth step by applying a vacuum to the powder reactor 10; And vi) a sixth step of recovering the adsorbent removed by vaporization of the impregnated material;

The second step is heated to 150 ~ 250 ℃, the fourth step is raised to 300 ~ 600 ℃, the fourth step is preferably carried out in a state filled with an inert gas.

In addition, the fourth step is performed while the pressure inside the powder reactor 10 is maintained at 3 bar or more by being filled with an inert gas, wherein the inert gas is nitrogen or argon gas, and the inert gas contains 3 to 10 oxygen. Included in volume %, and the impregnating material is Triethylenediamine (TEDA), 4,4-Diaminodicyclohexylmethane, H examethylenediamine, 1,4-Diazacycloheptane, Diphenylethylenediamine (DPEN), o-Phenylenediamin, m-Phenylenediamin, p-Phenylenediamin, Dimethyl-4 -phenylenediamine (DMPD), Tetramethyl-1,4-phenylendiamine (TMPD), 2,5-Diaminotoluene, 4-methoxyaniline, 3-Nitroaniline, and at least one selected from the group consisting of 4-Nitroaniline, the adsorbent is diatomaceous earth, silica gel , Activated carbon, zeolite, activated alumina and molecular sieve (Molecular sieve) is preferably any one of.

According to the method of regeneration of the waste impregnated adsorbent according to the present invention, the process is simple and economical compared to the existing waste impregnating adsorbent treatment technology, and the residual amount of tritium and radiocarbon in the treated waste impregnated adsorbent is less than the self-disposal limit. It has the effect of showing a much lower concentration. Therefore, after removing the radioactive material and the impregnated material from the waste impregnated adsorbent, the impregnated material is re-adhered to produce an impregnated adsorbent, which can be recycled in the exhaust system of a nuclear facility.

Accordingly, it is possible to solve the problem of incineration or solidification of the waste impregnated adsorbent, and since the amount of waste of the waste impregnated adsorbent is reduced, the waste disposal cost is greatly reduced.

In addition, since the waste impregnated adsorbent can be regenerated and recycled as a high-quality impregnated adsorbent, the eco-friendly effect can be maximized.

1 is a process flow diagram of a method for regenerating a waste impregnated adsorbent according to the present invention,
2 is a schematic diagram of an apparatus for removing radioactive materials and impregnated materials according to the present invention.

In the present application, terms such as "include", "have" or "have" are intended to designate the existence of features, numbers, steps, components, parts, or combinations thereof described in the specification. It is to be understood that it does not preclude the presence or addition of features, numbers, steps, actions, components, parts, or combinations thereof.

In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning of the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate an overall understanding, the same reference numerals are used for the same elements in the drawings, and duplicate descriptions for the same elements are omitted.

Hereinafter, a method for regenerating a waste impregnated adsorbent according to the present invention will be described in detail with reference to the accompanying drawings. 1 is a process flow diagram of a method for regenerating a waste impregnated adsorbent according to the present invention, and FIG. 2 is a schematic diagram of an apparatus 200 for removing radioactive materials and impregnated substances according to the present invention.

Radioactive materials, including reproducing method of pyecheom complex adsorbent according to the present invention, a nuclear installation of the exhaust gas treatment system of pyecheom complex carbon compounds containing radioactive carbon ⁽¹⁴ C) from the adsorbent and tritium in the ⁽³ H), etc. By simultaneously desorbing and desorbing the impregnated material, the waste impregnated adsorbent is regenerated as an adsorbent.

Adsorbents used for air purification in nuclear power plants are contaminated by radioactivity and cannot be recycled, and they cannot be disposed of on their own at nuclear power plants, and are classified as radioactive solid waste and stored in nuclear power plants. In particular, the adsorbent used in the air purification system (HVAC) of nuclear facilities is used for the purpose of removing iodine (I) and xenon (Xe) from the emitted radioactive gases. Attached substances such as TEDA and KI are attached. In addition, the domestic nuclear power plants and complex pyecheom adsorbent that is generated from nuclear facilities has a significant amount of radioactive carbon ⁽¹⁴ C) and tritium ⁽³ H) has been confirmed that it remains.

The method for regenerating the waste impregnation adsorbent according to the present invention includes: i) a first step of filling the waste adsorbent used in the powder reactor 10; Ⅱ) a second step for vaporizing the carbon compound, and tritium ⁽³ H) is adsorbed impregnated material containing radioactive carbon ⁽¹⁴ C). The temperature was raised to the powder reactor 10 from the mounting pyecheom adsorbent; Iii) a third step of discharging the impregnated material vaporized in the second step by applying a vacuum to the powder reactor 10; Ⅳ) a fourth step of gasifying carbon compounds and tritium (impregnated with ³ H) The absorbent material comprises a radioactive carbon ⁽¹⁴ C) remaining in the adsorbent by raising the temperature of the mounting pyecheom the powder reactor 10; V) a fifth step of discharging the impregnated material vaporized in the fourth step by applying a vacuum to the powder reactor 10; And vi) a sixth step of recovering the adsorbent removed by vaporization of the impregnated material.

According to the present invention, the radioactive material and impregnated material removing device 200 for regenerating the waste impregnated adsorbent is a powder reactor equipped with an impeller that facilitates mixing of the waste impregnated adsorbent therein, as shown in FIG. (10), an oxygen gas supply device 20 for supplying oxygen gas into the powder reactor 10, and an inert gas supply device 25 for supplying an inert gas into the powder reactor 10 ) And a supply gas mixing device 30 for mixing the inert gas and oxygen gas, a mixed gas preheater for preheating the temperature of the mixed gas supplied to the inside of the powder reactor 10 to increase the removal efficiency of radioactive substances and impregnated substances (40), a decompression tank 50 for controlling the pressure inside the powder reactor 10, a condenser 60 and a condensate storage tank 70 for condensing moisture and impregnated substances removed from the adsorbent, and a powder reactor ( 10) And a vacuum pump 80 for controlling the pressure of the transfer pipe, an oxidation catalytic reactor 90 for converting the removed radioactive material and impregnated material into a gas component before discharging, and a radioactive material among gas components generated as a result of the reaction It is characterized by consisting of a _{dry scrubber 100 for absorbing radioactive carbon dioxide (CO 2} ), which constitutes the main component of, and a discharge fan 12 for discharging unreacted gas including the remaining inert gas after absorbing the radioactive material.

As described above, the radioactive material and impregnated material removing device 200 for regenerating the waste impregnated adsorbent has been described, but the configuration of the radioactive material and impregnated material removing device 200 is not limited.

The method for regenerating the waste impregnated adsorbent according to the present invention is a first step of filling the waste impregnated adsorbent used in a nuclear power facility into the powder reactor 10 provided in the radioactive material and impregnated material removing device 200 as described above. Will go through.

The waste impregnated adsorbent is used in the air purification system of nuclear facilities such as nuclear power plants, and is mainly used for the purpose of removing radioactive iodine or radioactive xenon, which are radioactive gases in the air. In addition, the waste impregnated adsorbent may be impregnated with an impregnating material in order to increase the adsorption and removal efficiency thereof.

According to the present invention, the waste impregnation adsorbent preferably has a large specific surface area such as activated carbon, diatomaceous earth, silica gel, zeolite, activated alumina, and molecular sieve, as well as capable of adsorbing an inert gas well.

Among the adsorbents, activated carbon has a non-polar or bipolar surface due to oxide groups and inorganic impurities on the surface, and can adsorb more non-polar and bipolar molecules than other adsorbents because of its large specific surface area. It is an adsorbent that is used in various ways.

Zeolite is a crystalline aluminosilicate that has a three-dimensional structure of alkali or alkaline earth elements such as Na, K, and Ca. It contains a large amount of desorption-free moisture with a three-dimensional network structure, and has high cation exchange capacity (CEC: cation exchange capacity). ) And gas, and has a uniform pore diameter, so it is widely applied as a molecular sieve, an adsorbent, a desiccant, and an ion exchanger.

Diatomaceous earth is a porous soil that is formed by accumulating the remains of diatoms, which are very fine single-celled organisms, on the sea floor or under the lake. It has a white clay shape, is light, and has a very high absorption rate.

In addition, silica gel is a transparent grain-shaped porous material made by treating an aqueous solution of sodium silicate with an acid. Since the silica gel has a large surface area, high mechanical strength against impact and friction, and strong in contact with moisture, it is the most widely used adsorbent as a dehumidifying agent.

In addition, the molecular sieve maintains relatively high adsorption properties regardless of relative humidity, and unlike silica gel and alumina gel, whose adsorption rate rapidly decreases with temperature, the adsorption rate gradually decreases, so the temperature is high. Or when the relative humidity is low.

According to the present invention, the adsorbent as described above is characterized in that an impregnation material is impregnated on the pore surface in order to increase the adsorption efficiency of radioactive gas such as radioactive iodine or radioactive xenon in air.

In the present invention, impregnation is also referred to as impregnation, and means that the impregnating material penetrates into the pore surface of the adsorbent to completely adhere to it.

According to the present invention, the impregnating material is Triethylenediamine (TEDA), 4,4-Diaminodicyclohexylmethane, hexamethylenediamine, 1,4-Diazacycloheptane, Diphenylethylenediamine (DPEN ), o -Phenylenediamin e , m -Phenylenediamin e , p -Phenylenediamin e , Dimethyl- At least one selected from the group consisting of 4-phenylenediamine (DMPD), Tetramethyl-1,4-phenylendiamine (TMPD), 2,5-Diaminotoluene, Dimethyl-4-phenylenediamine, 4-methoxyaniline, 3-Nitroaniline, and 4-Nitroaniline desirable.

The impregnated material according to the present invention is preferably in a solid state at room temperature and vaporized at 150 to 300°C.

As the first step as described above, the waste impregnated adsorbent filled into the inside of the powder reactor 10 provided in the radioactive material and impregnated material removal device 200 is then the powder reactor 10 as shown in FIG. the temperature was raised to pyecheom radioactive material and the radioactive material is adsorbed impregnated materials, such as carbon-carbon compounds and tritium ⁽³ H) containing ⁽¹⁴ C) is subjected to the second step to one vaporized away from the complex adsorbent.

The second step is a step of vaporizing the radioactive material such as radioactive carbon adsorption in the impregnated material impregnated in complex adsorbent contaminated pyecheom carbon compounds and tritium containing ⁽¹⁴ C) ⁽³ H) from the pyecheom complex adsorbent , By raising the temperature of the powder reactor 10 to 150 ~ 300 °C, the radioactive material and the impregnated material are vaporized at the same time. That is, when the temperature inside the powder reactor 10 is raised to 150 to 300° C., the impregnated material is converted to a gaseous state and is mostly vaporized from the waste impregnated adsorbent.

At this time, as the material is vaporized chamchak is vaporized with even radioactive substance, such as carbon compounds, and tritium ⁽³ H) including a radioactive carbon ⁽¹⁴ C) adsorbed on the impregnated material.

The impregnated material vaporized from the waste impregnated adsorbent as described above is vacuumed to the powder reactor 10 as a third step to discharge the vaporized impregnated material to the outside of the powder reactor 10 first.

In the second step, most of the impregnated material impregnated into the waste impregnated adsorbent is vaporized and removed, but the impregnated material remaining in the micropores of the waste impregnated adsorbent is completely removed, and the surface and structure of the waste impregnated adsorbent are functionalized to achieve vacuum. In order to activate the waste impregnated activated carbon during heat treatment, as a fourth step, the powder reactor 10 is reheated to vaporize and completely remove the radioactive material remaining in the waste impregnation adsorbent by vaporizing the adsorbed impregnated material.

According to the present invention, the fourth step is characterized in that the inside of the powder reactor 10 is heated to 300 ~ 600 °C. That is, when the temperature of the powder reactor 10 is raised to a temperature exceeding 600° C., the adsorbent may be carbonized and burned, so it is preferable to increase the temperature to 300 to 600° C.

That is, in order to remove the impregnated material as described above, the removal rate increases as the temperature of the powder reactor 10 increases, but when the temperature is raised to a temperature exceeding 600° C., the adsorbent is burned and regeneration becomes impossible.

Therefore, raising the temperature of the powder reactor 10 to 300 ~ 600 ℃ in the fourth step increases the vaporization rate of the impregnated material and smoothly regenerates the adsorbent without disrupting the microporous structure of the waste impregnated adsorbent. Can be.

According to the present invention, the fourth step is characterized in that it is performed after filling the inner space of the powder reactor 10 with an inert gas. It is preferable that the pressure inside the powder reactor 10 filled with an inert gas as described above is maintained at 3 bar or more.

That is, according to the present invention, the pressure inside the powder reactor 10 can be maintained at 3 bar or more by increasing the flow rate of the inert gas into the powder reactor 10.

In addition, according to the present invention, the inert gas flowing into the reactor in the fourth step is either nitrogen gas or argon gas, and the inert gas preferably contains 3 to 10% by volume of oxygen.

In the case of raising the internal temperature of the powder reactor 10 to 300 to 600°C by introducing an inert gas containing 3 to 10% by volume of oxygen into the powder reactor 10 in the fourth step as described above, The waste impregnated adsorbent is not combusted, and only the impregnated material attached to the waste impregnated adsorbent can be burned.

As described above, by burning only the impregnated material attached to the waste impregnated adsorbent without combustion of the impregnated adsorbent through the fourth step, regeneration of the adsorbent is possible without changing the pore structure.

In the fourth step, the impregnated material vaporized from the waste impregnated adsorbent goes through a fifth step in which a vacuum is applied to the powder reactor 10 and discharged to the second step.

According to the invention, a radioactive substance, such as carbon compounds, and tritium ⁽³ H) containing a ^carbon-(14 C) contained in the impregnated material discharged in the first step and the second step 42 it is processed through a process known It is done .

That is, a radioactive substance, such as carbon compounds, and tritium ⁽³ H) including a radioactive carbon ⁽¹⁴ C) collecting said complex pyecheom sorbent is disposed of in solidified by cement solidification or the like asphalt solidification.

According to the present invention, the second and fourth steps of vaporizing the impregnated material from the waste impregnated activated carbon are preferably performed in a stirring state using an impeller provided in the powder reactor 10.

In the case of performing the second and fourth steps while stirring the waste impregnated adsorbent filled in the powder reactor 10 as described above using an impeller, the waste impregnated adsorbent is uniformly heated so that the vaporization of the impregnated material is uniform. And accordingly, the regeneration efficiency of the waste impregnated adsorbent can be increased.

When the vaporized impregnated material is discharged from the waste impregnated adsorbent in the fifth step as described above, the regeneration of the waste impregnated adsorbent according to the present invention is completed by recovering the regenerated adsorbent in the sixth step.

Hereinafter, examples will be described in detail in order to describe the present invention in detail. However, embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art. In addition, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below.

<Comparative Example 1>

Impregnated activated carbon prepared by impregnating TEDA as an impregnating material using activated carbon, which is an adsorbent used in the air purification system of nuclear power plants, was used. _{As the radioactive material, the impregnated activated carbon was contaminated with a certain radioactive concentration using radioactive carbon dioxide (CO 2} ), which is a radioactive material generated in the air purification system of a nuclear power plant, and then used as a test piece of <Comparative Example 1> without performing a regeneration process Was used.

<Comparative Example 2>

In <Comparative Example 1>, impregnated activated carbon contaminated with an arbitrary radioactivity concentration was filled in the powder reactor 10, and the temperature of the powder reactor 10 was raised to 250°C, and then operated for 90 minutes without supply of an inert gas to be radioactive. The substance and the sesame seed were first vaporized, and the vaporized radioactive material and the sessile material were discharged, and then used as a test piece of <Comparative Example 2>.

<Comparative Example 3>

As in <Comparative Example 2>, the impregnated activated carbon from which the radioactive material and the sessile material were first removed was heated to 250° C., and nitrogen gas containing no oxygen was introduced into the powder reactor 10. It was supplied and operated for 90 minutes under the condition that the pressure inside the powder reactor 10 was 3 bar, and the radioactive material and the sesame material were vaporized and discharged secondarily, and used as a test piece of <Comparative Example 3>.

<Example 1>

After filling the powder reactor 10 with impregnated activated carbon from which radioactive materials and sessile materials were first removed as in Comparative Example 2, the temperature of the powder reactor 10 was raised to 300°C, and 3% by volume of oxygen was added. While supplying containing nitrogen gas to the inside of the powder reactor 10, it was operated for 90 minutes under a condition of maintaining a pressure of 2 bar to secondly evaporate and discharge radioactive materials and sesame substances to the test piece of <Example 1>. Was used.

<Example 2>

After filling the powder reactor 10 with impregnated activated carbon from which radioactive materials and sessile materials were first removed as in Comparative Example 2, the temperature of the powder reactor 10 was raised to 450°C, and 5% by volume of oxygen was added. While supplying containing nitrogen gas to the inside of the powder reactor 10 and maintaining a pressure of 3 bar for 90 minutes, the radioactive material and the impregnated material were secondarily vaporized and discharged to obtain a test piece of <Example 2>. Was used.

<Example 3>

After filling the powder reactor 10 with impregnated activated carbon from which radioactive materials and sessile materials were first removed as in Comparative Example 2, the temperature of the powder reactor 10 was raised to 600°C, and 10% by volume of oxygen was added. While supplying containing nitrogen gas to the inside of the powder reactor 10 and maintaining a pressure of 3 bar for 90 minutes, the radioactive material and the impregnated material were secondarily vaporized and discharged to the test piece of <Example 3>. Was used.

And the radioactivity concentration and the impregnated material for the <Comparative Examples 1 to 3> and <Examples 1 to 3> were evaluated in the following manner.

1) Measurement of radioactive concentration

Radioactive carbon was collected using 3-methoxypropylamine, a collection solution, by heating the test piece to 900°C using a high-temperature combustion furnace. The concentration of radioactive carbon was measured using a liquid scintillation counter, which had been calibrated for efficiency using a standard solution of radioactive carbon, after taking a certain amount of the collection solution in which radioactive carbon was collected and mixing it with the scintillation solution.

2) Measurement of sesame substance

TEDA remaining after being applied to activated carbon was measured by GC-FID (Gas Chromatography-Flame Ionization Detection) analysis.

3) Measurement of weight loss rate of impregnated activated carbon

The weight loss rate (%) according to the regeneration process of the waste impregnated activated carbon according to the present invention was measured according to the following equation.

Table 1 shows the results of measuring the residual concentration of TEDA for the test pieces of <Comparative Examples 1 to 3> and <Examples 1 to 3>.

Sample name Test Items Test Methods Test result Comparative Example 1 Triethylenediamine
(TEDA) GC-FID 5.51% by weight Comparative Example 2 3.52% by weight Comparative Example 3 2.23% by weight Example 1 Not detected Example 2 Not detected Example 3 Not detected

As shown in <Table 1>, as a result of measuring the concentration of TEDA with respect to the test pieces of <Comparative Examples 1 to 3>, the test piece of <Comparative Example 1>, that is, the removal process of the radioactive material and the sesame substance according to the present invention It was determined that 5.51% by weight of TEDA was attached to the test piece that was not carried out.

In addition, after filling the powder reactor 10 with impregnated activated carbon contaminated with an arbitrary radioactivity concentration in <Comparative Example 1>, the temperature of the powder reactor 10 was raised to 250 °C, and the temperature was raised to 250 °C to obtain an inert gas. In the case of the test piece of <Comparative Example 2> prepared by first evaporating radioactive materials and sesame substances by operating for 90 minutes without supply of, and discharging the evaporated radioactive substances and sesame substances, 3.52% by weight of TEDA was impregnated. It was measured to be.

And after filling the powder reactor 10 with impregnated activated carbon from which the radioactive material and the trapping material were first removed as in Comparative Example 3, the temperature of the powder reactor 10 was raised to 250°C, and the temperature of the powder reactor 10 was raised to 250°C. <Comparative Example 3, wherein nitrogen gas was supplied to the inside of the powder reactor 10 and operated for 90 minutes under the condition that the pressure inside the powder reactor 10 was 3 bar, and then radioactive materials and sesame substances were secondarily vaporized and discharged. In the case of the test piece of >, it was determined that 2.23% by weight of TEDA was attached.

That is, as in <Comparative Example 2> and <Comparative Example 3>, when removing radioactive materials and sessile substances, only the temperature of the powder reactor 10 is raised to 250°C, or oxygen is included in the powder reactor 10. In the case of supplying only nitrogen gas that has not been performed, there is no oxygen capable of combusting the impregnated material inside the powder reactor 10, so that the impregnated material is not burned, and a significant amount of the impregnated material remains.

However, when the radioactive material and the sesame material according to the present invention are first and secondly vaporized and discharged, the temperature of the powder reactor 10 is raised to 300° C. or higher, and at the same time, nitrogen gas containing 3 to 10% by volume of oxygen is Under the condition of maintaining a pressure of 3 bar while supplying the powder to the inside of the powder reactor 10, all of the TEDA impregnated on the pore surface of the activated carbon was burned by oxygen, so that TEDA was not detected from the test pieces of <Examples 1 to 3>. I didn't.

That is, in the test piece regenerated by the method for regenerating the waste impregnated adsorbent according to the present invention, it was determined that all TEDA was vaporized and not detected.

In addition, the results of measuring the concentration of radioactive carbon in the test pieces of <Comparative Examples 1 to 3> and <Examples 1 to 3> are shown in <Table 2>.

Sample name Test Items Test Methods Test result (Bq/g) Comparative Example 1 Radioactive carbon Liquid scintillation counting method 4.68 Comparative Example 2 3.21 Comparative Example 3 3.10 Example 1 0.459 Example 2 0.452 Example 3 0.338

As shown in <Table 2>, the concentration of radioactive carbon was measured in the range of 0.338 to 0.459 Bq/g from the test pieces of <Examples 1 to 3>, and 3.10 to 4.68 Bq of the test pieces of <Comparative Examples 1 to 3> Radioactivity concentration in the range of /g was measured.

That is, in the case of the test pieces of <Examples 1 to 3> according to the present invention, most of the radioactive carbon was burned and vaporized together with the impregnated material, so that the concentration of radioactive carbon was 0.459 Bq/g or less, so that the activated carbon was appropriately regenerated. It can be confirmed that it was done.

And, the weight loss for the test pieces of <Examples 1 to 3> is shown in <Table 3>.

Sample name Weight of input activated carbon (g) Weight of activated carbon after treatment (g) Weight loss rate (%) Example 1 250 236 5.6 Example 2 250 234 6.4 Example 3 250 233 6.8

In the case of the test pieces of <Examples 1 to 3>, weight loss occurred in 5.6% to 6.8% after treatment. From this, it can be confirmed that the activated carbon has been sufficiently regenerated so that it can be reused without significant deformation of the shape and pore characteristics of the activated carbon.

As described above, the adsorbent can be reused by re-adhering the impregnated material to the treated adsorbent by removing only the radioactive material and the adsorbent material without changing the shape and pore characteristics of the activated carbon.

As described above, according to the regeneration method of the waste impregnation adsorbent according to the present invention, the residual amounts of tritium and radiocarbon in the waste adsorbent can be regenerated at a concentration much lower than the self-disposal limit without changing the pore structure. By attaching it, it can be recycled in the exhaust system of nuclear facilities. Accordingly, waste treatment costs can be greatly reduced, and eco-friendly effects can be maximized.

The present invention has been described with reference to the experimental examples shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent other experimental examples are possible therefrom. In addition, those of ordinary skill in the art to which the present invention pertains will be able to understand that it is possible to easily transform into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative and non-limiting in all respects, and the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: powder reactor
12: exhaust fan
20: oxygen gas supply device
25: inert gas supply device
60: condenser
70: condensate storage tank
100: dry scrubber
200: radioactive material and impregnated material removal device

Claims (6)

A radioactive carbon ⁽¹⁴ C) carbon compounds and tritium play pyecheom method of mounting the adsorbent ⁽³ H) is adsorbed containing,
I) a first step of filling the waste impregnated adsorbent used in the powder reactor 10;
Ⅱ) a second step for vaporizing the carbon compound, and tritium ⁽³ H) is adsorbed impregnated material comprising the powder reactor 10. The radiocarbon ⁽¹⁴ C the temperature was raised to 150 ~ 300 ℃) from the pyecheom complex adsorbent ;
Iii) a third step of discharging the impregnated material vaporized in the second step by applying a vacuum to the powder reactor 10;
Iv) By raising the temperature of the powder reactor 10 to 300 ~ 600 ℃ and introducing an inert gas containing 3 ~ 10% by volume of oxygen, the internal pressure of the powder reactor 10 is maintained at 3 bar, carbon-carbon compounds and tritium containing ⁽¹⁴ C) remaining in the fourth step of ⁽³ H) vaporizing the impregnated adsorbent material;
V) a fifth step of discharging the impregnated material vaporized in the fourth step by applying a vacuum to the powder reactor 10; And
Vi) a sixth step of recovering the adsorbent removed by vaporization of the impregnated material.
The method according to claim 1,
The fourth step is a method for regenerating a waste impregnated adsorbent, characterized in that it is performed while supplying an inert gas.
The method according to claim 2,
The fourth step is a method of regenerating a waste impregnated adsorbent, characterized in that the fourth step is carried out while the pressure inside the powder reactor 10 is maintained at 3 bar or more by being filled with an inert gas.
The method according to claim 2,
The inert gas is nitrogen or argon gas, characterized in that the waste impregnated adsorbent regeneration method.
The method according to claim 1,
The impregnating material is Triethylenediamine (TEDA), 4,4-Diaminodicyclohexylmethane, hexamethylenediamine, 1,4-Diazacycloheptane, Diphenylethylenediamine ( DPEN), o -Phenylenediamine, m -Phenylenediamine, p -Phenylenediamine, Dimethyl-4-phenylenediamine (DMPD), Tetramethyl -1,4-phenylendiamine (TMPD), 2,5-Diaminotoluene, 4-methoxyaniline, 3-Nitroaniline, 4-Nitroaniline regeneration method of the impregnated adsorbent, characterized in that at least one selected from the group consisting of.
The method according to claim 1,
The adsorbent is a method for regenerating a waste impregnated adsorbent, characterized in that any one of diatomaceous earth, silica gel, activated carbon, zeolite, activated alumina, and molecular sieve.

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