Chemical absorption liquid for removing methyl iodide and preparation method thereof

Abstract

The invention relates to a chemical absorption liquid for removing methyl iodide and a preparation method thereof, and belongs to the technical field of underwriting. The chemical absorption liquid comprises the following raw materials in percentage by mass: 0.2-5% of sodium thiosulfate, 1-10% of long-chain alkyl trimethyl ammonium halide, 0-1% of sodium hydroxide, 0-10% of polyethylene polyamine and the balance of water. The number of long-chain carbon atoms in the long-chain alkyl trimethyl ammonium halide is greater than 8; the chemical absorption liquid is prepared by completely dissolving and uniformly mixing the components. According to the chemical absorption liquid, the long-chain alkyl trimethyl ammonium halide salt is introduced as a surfactant for the first time, has a solubilizing effect, and can greatly reduce the gas-liquid mass transfer resistance of methyl iodide, so that efficient absorption of radioactive and non-radioactive methyl iodide is realized; the chemical absorption liquid is not only suitable for normal temperature, but also suitable for high-temperature and high-humidity environments, and harmful gas can be purified in a solution washing or solution spraying mode.

Description

TECHNICAL FIELD

[0001] The present application relates to a chemical absorption liquid for removing methyl iodide and a preparation method thereof, and belongs to the field of environmental protection. BACKGROUND

[0002] Methyl iodide is a kind of radioactive substance, which is released from the reactor in the state of severe accident of nuclear power plant. Methyl iodide is chemically inert and volatile, and can be enriched in human thyroid through breathing, causing long-term high-dose irradiation of human thyroid and leading to thyroid cancer.

[0003] The existing chemical absorption liquid for absorbing the leaked radioactive methyl iodide in the state of severe accident of nuclear power plant mainly consists of sodium hydroxide, sodium thiosulfate and deionized water, but the removal efficiency of the chemical absorption liquid for radioactive methyl iodide is low. In order to improve the removal efficiency of the chemical absorption liquid for radioactive methyl iodide, the Paul Scherrer Institute in Switzerland proposes to directly add a phase transfer catalyst such as Aliquat 336 (trade name) into the chemical absorption liquid. However, the phase transfer catalyst is difficult to dissolve in water, and will be stratified and aggregated after a long time, resulting in poor stability of the chemical absorption liquid, and the phase transfer catalyst has the risk of being flammable and explosive.

[0004] The Chinese patent application with the publication number CN 117373719A discloses a chemical absorption liquid for removing radioactive methyl iodide, which adds polyethylene polyamine into the sodium thiosulfate and sodium hydroxide solution to improve the absorption efficiency of the absorption liquid for methyl iodide. The addition of 1% diethylene triamine in the mass fraction of (1% sodium thiosulfate + 0.5% sodium hydroxide) aqueous solution can improve the absorption efficiency of methyl iodide from 30% to 41%. Although the addition of diethylene triamine can improve the absorption efficiency of the absorption liquid for methyl iodide to a certain extent, the improvement is limited. The literature research results (Atomic Energy Science and Technology, Vol. 47, No. 11, 2013. P 2125-P2130) show that the main reason for the low absorption efficiency of the alkaline sodium thiosulfate absorption liquid for methyl iodide is the large gas-liquid mass transfer resistance of methyl iodide. Although the addition of polyethylene polyamine can reduce the mass transfer resistance to a certain extent and improve the absorption efficiency of the absorption liquid for methyl iodide, the improvement is limited.

[0005] Therefore, it is still necessary to further develop an absorption liquid with higher absorption efficiency for methyl iodide to reduce the release of radioactivity and protect the safety of people and the surrounding environment. SUMMARY

[0006] In order to overcome the defects of the prior art, the present application aims to provide a chemical absorption liquid for removing methyl iodine and a preparation method thereof, wherein long-chain alkyl trimethyl ammonium halide salt is first introduced as a component of the chemical absorption liquid, and a chemical absorption liquid capable of safely, stably and efficiently removing methyl iodine is obtained.

[0007] In order to achieve the object of the present application, the following technical solutions are provided.

[0008] A chemical absorption liquid for removing methyl iodine, wherein, based on the total mass of raw materials of the chemical absorption liquid being 100%, the components and their mass fractions are as follows:

[0009]

[0010] The number of carbon atoms in the long-chain alkyl trimethyl ammonium halide salt is greater than 8, and if the number of carbon atoms is too low, the long-chain alkyl trimethyl halide salt tends to lose the effect of removing methyl iodine in the absorption liquid.

[0011] Further, the halogenation in the long-chain alkyl trimethyl ammonium halide salt refers to chlorination or bromination, that is, the long-chain alkyl trimethyl ammonium halide salt is long-chain alkyl trimethyl ammonium chloride salt or long-chain alkyl trimethyl ammonium bromide salt.

[0012] Still further, the long-chain alkyl trimethyl ammonium halide salt is cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride or octadecyl trimethyl ammonium chloride.

[0013] Further, the polyethylene polyamine is at least one of diethylene triamine, triethylene tetramine and tetraethylene pentamine.

[0014] A preparation method of the chemical absorption liquid for removing methyl iodine according to the present application, and the method steps are as follows:

[0015] First, sodium thiosulfate and sodium hydroxide are dissolved in water, and then polyethylene polyamine and long-chain alkyl trimethyl ammonium halide salt are added in sequence, and stirring is performed until all components are completely dissolved and uniformly mixed, to obtain a chemical absorption liquid for removing methyl iodine; when the mass fraction of polyethylene polyamine and / or sodium hydroxide is 0%, the substance with a mass fraction of 0% is not added.

[0016] Advantages

[0017] (1) The present application provides a chemical absorption liquid for removing methyl iodine, wherein long-chain alkyl trimethyl ammonium halide salt is first introduced as a surfactant, has a solubilizing effect, can greatly reduce the mass transfer resistance between gas and liquid of methyl iodine, and thus realizes the purpose of high-efficiency absorption of methyl iodine by the absorption liquid.

[0018] (2) The present application provides a chemical absorption solution for removing methyl iodide, which first introduces long-chain alkyl trimethyl ammonium halide salt. Because long-chain alkyl trimethyl ammonium halide salt has good solubility in water, it can form a uniform, stable and safe aqueous solution, and there is no risk of separation from water or explosion.

[0019] (3) The present application provides a chemical absorption solution for removing methyl iodide, which first introduces long-chain alkyl trimethyl ammonium halide salt. The number of long-chain carbon atoms in long-chain alkyl trimethyl ammonium halide salt needs to be greater than 8. If the carbon number is too low, the removal effect of long-chain alkyl trimethyl ammonium halide salt on methyl iodide in the absorption solution will tend to disappear.

[0020] (4) The present application provides a chemical absorption solution for removing methyl iodide, which is not only suitable for normal temperature conditions, but also suitable for high temperature and high humidity conditions.

[0021] (5) The present application provides a chemical absorption solution for removing methyl iodide, which can not only purify harmful gases by solution washing method, but also purify harmful gases by solution spraying method.

[0022] (6) The present application provides a chemical absorption solution for removing methyl iodide, which is not only suitable for the purification of radioactive iodine and methyl iodide, but also suitable for the efficient removal of non-radioactive methyl iodide. DETAILED DESCRIPTION

[0023] The present application will be further described in conjunction with specific embodiments, wherein the methods are all conventional methods unless otherwise specified, and the raw materials can be obtained from public commercial channels unless otherwise specified.

[0024] The absorption efficiency of the chemical absorption solution prepared in Test Examples 1-12 and Comparative Examples 1-4 on methyl iodide was tested, and the testing method was as follows:

[0025] A mixture of methyl iodide and air was used as sample gas, and the mass concentration of methyl iodide in the sample gas was 50 mg / m 3 A stainless steel tank with an inner diameter of 20 cm and a height of 1.5 m was used as an absorption cell, and 50 kg of the chemical absorption solution was added to the absorption cell; the sample gas was preheated to the absorption temperature, and then introduced into the sample cell at a flow rate of 10 L / min; the temperature of the sample cell was set to be the same as the preheating temperature, and the pressure of the sample cell was the absorption pressure; after the sample gas was fully reacted with the chemical absorption solution in the absorption cell, it was discharged from the sampling port; Agilent 7890A gas chromatography was used to detect the concentration of methyl iodide in the sample gas at the sampling port, and the detector of the gas chromatography was an electron capture detector (ECD).

[0026] Example 1

[0027] A chemical absorption solution for removing methyl iodide, each component and its mass fraction, based on the total mass of the raw materials of the chemical absorption solution being 100%, are as follows:

[0028] Sodium thiosulfate 0.2%, cetyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, and the rest is deionized water.

[0029] A preparation method of the chemical absorption solution for removing methyl iodide described in the present embodiment, the method steps are as follows:

[0030] Sodium thiosulfate, sodium hydroxide, and cetyltrimethylammonium chloride are sequentially added to deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0031] Performance test:

[0032] The chemical absorption solution described in the present embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is atmospheric pressure, and the absorption temperature is 80°C. The test results show that the absorption efficiency of the chemical absorption solution described in Example 1 for methyl iodide in sample gas can reach 78%.

[0033] Example 2

[0034] A chemical absorption solution for removing methyl iodide, each component and its mass fraction, based on the total mass of the raw materials of the chemical absorption solution being 100%, are as follows:

[0035] Sodium thiosulfate 5%, cetyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, and the rest is deionized water.

[0036] A preparation method of the chemical absorption solution for removing methyl iodide described in the present embodiment, the method steps are as follows:

[0037] Sodium thiosulfate, sodium hydroxide, and cetyltrimethylammonium chloride are sequentially added to deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0038] Performance test:

[0039] The chemical absorption solution described in the present embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3The ratio of the mass of the chemical absorption liquid (kg) to the concentration of methyl iodide in the sample gas (mg / m

[0040] Example 3

[0041] A chemical absorption liquid for removing methyl iodide, each component and its mass fraction, based on the total mass of the raw materials of the chemical absorption liquid being 100%, are as follows:

[0042] Sodium thiosulfate 1%, hexadecyl trimethyl ammonium bromide 1%, sodium hydroxide 0.5%, diethylene triamine 10%, and the rest is deionized water.

[0043] A preparation method of the chemical absorption liquid for removing methyl iodide described in the present embodiment, the method steps are as follows:

[0044] Sodium thiosulfate, sodium hydroxide, diethylene triamine, and hexadecyl trimethyl ammonium bromide are sequentially added to deionized water in turn, and stirred until each component is completely dissolved and uniformly mixed, to obtain a chemical absorption liquid for removing methyl iodide.

[0045] Performance test:

[0046] The chemical absorption liquid described in the present embodiment is used to absorb methyl iodide in sample gas, the mass of the chemical absorption liquid (kg) and the concentration of methyl iodide in the sample gas (mg / m 3 The ratio of the mass of the chemical absorption liquid (kg) to the concentration of methyl iodide in the sample gas (mg / m

[0047] Example 4

[0048] A chemical absorption liquid for removing methyl iodide, each component and its mass fraction, based on the total mass of the raw materials of the chemical absorption liquid being 100%, are as follows:

[0049] Sodium thiosulfate 1%, hexadecyl trimethyl ammonium chloride 10%, sodium hydroxide 0.5%, diethylene triamine 10%, and the rest is deionized water.

[0050] A preparation method of the chemical absorption liquid for removing methyl iodide described in the present embodiment, the method steps are as follows:

[0051] Sodium thiosulfate, sodium hydroxide, diethylene triamine, and hexadecyl trimethyl ammonium chloride are sequentially added to deionized water in turn, and stirred until each component is completely dissolved and uniformly mixed, to obtain a chemical absorption liquid for removing methyl iodide.

[0052] Performance test:

[0053] The chemical absorption liquid of the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1, the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid of the embodiment 4 for methyl iodide in sample gas can reach 98%.

[0054] Embodiment 5

[0055] A chemical absorption liquid for removing methyl iodide, wherein the total mass of raw materials of the chemical absorption liquid is 100%, and the components and mass fractions are as follows:

[0056] 1% of sodium thiosulfate, 10% of cetyltrimethylammonium chloride, 10% of diethylenetriamine, and the rest is deionized water.

[0057] A preparation method of the chemical absorption liquid for removing methyl iodide of the embodiment, and the method steps are as follows:

[0058] Sodium thiosulfate, diethylenetriamine, and cetyltrimethylammonium chloride are sequentially added into deionized water in sequence, and stirred until the components are completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0059] Performance test:

[0060] The chemical absorption liquid of the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1, the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid of the embodiment 5 for methyl iodide in sample gas can reach 98%.

[0061] Embodiment 6

[0062] A chemical absorption liquid for removing methyl iodide, wherein the total mass of raw materials of the chemical absorption liquid is 100%, and the components and mass fractions are as follows:

[0063] 1% of sodium thiosulfate, 10% of cetyltrimethylammonium chloride, 1% of sodium hydroxide, 10% of diethylenetriamine, and the rest is deionized water.

[0064] A preparation method of the chemical absorption liquid for removing methyl iodide of the embodiment, and the method steps are as follows:

[0065] Sodium thiosulfate, diethylenetriamine, and cetyltrimethylammonium chloride are sequentially added into deionized water in sequence, and stirred until the components are completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0066] Performance test:

[0067] The chemical absorption solution of the embodiment was used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in the sample gas was 1:1, the absorption pressure was normal pressure, and the absorption temperature was 80°C. The test results showed that the absorption efficiency of the chemical absorption solution of Example 6 for methyl iodide in sample gas could reach 98%.

[0068] Example 7

[0069] A chemical absorption solution for removing methyl iodide, with the total mass of raw materials of the chemical absorption solution being 100%, the components and mass fractions thereof being as follows:

[0070] Sodium thiosulfate 1%, dodecyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, diethylenetriamine 10%, and the rest being deionized water.

[0071] A preparation method of the chemical absorption solution for removing methyl iodide of the embodiment, the steps of the method being as follows:

[0072] Sodium thiosulfate, sodium hydroxide, diethylenetriamine, and dodecyltrimethylammonium chloride were sequentially added to deionized water, and stirred until the components were completely dissolved and uniformly mixed, to obtain a chemical absorption solution for removing methyl iodide.

[0073] Performance test:

[0074] The chemical absorption solution of the embodiment was used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in the sample gas was 1:1, the absorption pressure was normal pressure, and the absorption temperature was 80°C. The test results showed that the absorption efficiency of the chemical absorption solution of Example 7 for methyl iodide in sample gas could reach 69%.

[0075] Example 8

[0076] A chemical absorption solution for removing methyl iodide, with the total mass of raw materials of the chemical absorption solution being 100%, the components and mass fractions thereof being as follows:

[0077] Sodium thiosulfate 1%, dodecyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, diethylenetriamine 10%, and the rest being deionized water.

[0078] A preparation method of the chemical absorption solution for removing methyl iodide of the embodiment, the steps of the method being as follows:

[0079] Sodium thiosulfate, sodium hydroxide, diethylene triamine and tetradecyl trimethyl ammonium chloride are added into deionized water in sequence, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0080] Performance test:

[0081] The chemical absorption solution described in the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1, the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption solution described in Example 8 for methyl iodide in sample gas can reach 89%.

[0082] Example 9

[0083] A chemical absorption solution for removing methyl iodide, with the total mass of raw materials of the chemical absorption solution being 100%, each component and the mass fraction thereof are as follows:

[0084] Sodium thiosulfate 1%, octadecyl trimethyl ammonium chloride 1%, sodium hydroxide 0.5%, diethylene triamine 10%, and the rest is deionized water.

[0085] A preparation method of the chemical absorption solution for removing methyl iodide described in the embodiment, the method steps are as follows:

[0086] Sodium thiosulfate, sodium hydroxide, diethylene triamine and octadecyl trimethyl ammonium chloride are added into deionized water in sequence, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0087] Performance test:

[0088] The chemical absorption solution described in the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption solution described in Example 9 for methyl iodide in sample gas can reach 99%.

[0089] Example 10

[0090] A chemical absorption solution for removing methyl iodide, with the total mass of raw materials of the chemical absorption solution being 100%, each component and the mass fraction thereof are as follows:

[0091] Sodium thiosulfate 1%, octadecyl trimethyl ammonium chloride 1%, sodium hydroxide 0.5%, diethylene triamine 10%, and the rest is deionized water.

[0092] A preparation method of the chemical absorption liquid for removing methyl iodide is provided in the embodiment, and the method steps are as follows:

[0093] Sodium thiosulfate, sodium hydroxide, diethylene triamine and cetyl trimethyl ammonium bromide are sequentially added into deionized water in turn, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0094] Performance test:

[0095] The chemical absorption liquid in the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1, the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid in Example 10 for methyl iodide in sample gas can reach 93%.

[0096] Example 11

[0097] A chemical absorption liquid for removing methyl iodide, wherein, based on the total mass of raw materials of the chemical absorption liquid being 100%, the components and mass fractions thereof are as follows:

[0098] Sodium thiosulfate 1%, cetyl trimethyl ammonium chloride 1%, sodium hydroxide 0.5%, triethylene tetramine 10%, and the rest is deionized water.

[0099] A preparation method of the chemical absorption liquid for removing methyl iodide is provided in the embodiment, and the method steps are as follows:

[0100] Sodium thiosulfate, sodium hydroxide, diethylene triamine and cetyl trimethyl ammonium bromide are sequentially added into deionized water in turn, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0101] Performance test:

[0102] The chemical absorption liquid in the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in the sample gas is 1:1, the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid in Example 11 for methyl iodide in sample gas can reach 94%.

[0103] Example 12

[0104] A chemical absorption liquid for removing methyl iodide, wherein, based on the total mass of raw materials of the chemical absorption liquid being 100%, the components and mass fractions thereof are as follows:

[0105] Sodium thiosulfate 1%, cetyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, tetraethylenepentamine 10%, and the rest is deionized water.

[0106] A preparation method of the chemical absorption liquid for removing methyl iodide according to the embodiment, the method steps are as follows:

[0107] Sodium thiosulfate, sodium hydroxide, diethylenetriamine and cetyltrimethylammonium chloride are sequentially added into deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0108] Performance test:

[0109] The chemical absorption liquid according to the embodiment is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid according to Example 12 for methyl iodide in sample gas can reach 89%.

[0110] Comparative Example 1

[0111] A chemical absorption liquid for removing methyl iodide, in which the total mass of raw materials of the chemical absorption liquid is 100%, the components and their mass fractions are as follows:

[0112] Sodium thiosulfate 1%, sodium hydroxide 0.5%, and the rest is deionized water.

[0113] A preparation method of the chemical absorption liquid for removing methyl iodide according to the comparative example, the method steps are as follows:

[0114] Sodium thiosulfate and sodium hydroxide are added into deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption liquid for removing methyl iodide.

[0115] Performance test:

[0116] The chemical absorption liquid according to the comparative example is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption liquid to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption liquid according to Comparative Example 1 for methyl iodide in sample gas can reach 30%.

[0117] Comparative Example 2

[0118] A chemical absorption liquid for removing methyl iodide, in which the total mass of raw materials of the chemical absorption liquid is 100%, the components and their mass fractions are as follows:

[0119] Cetyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, and the rest is deionized water.

[0120] A preparation method of the chemical absorption solution for removing methyl iodide according to the present comparison example, the steps of the method are as follows:

[0121] Cetyltrimethylammonium chloride and sodium hydroxide are added to deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0122] Performance test:

[0123] The chemical absorption solution according to the present comparison example is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test results show that the absorption efficiency of the chemical absorption solution according to the present comparison example for methyl iodide in sample gas can reach 23%.

[0124] Comparison Example 3

[0125] A chemical absorption solution for removing methyl iodide, in which the total mass of raw materials of the chemical absorption solution is 100%, the components and their mass fractions are as follows:

[0126] Sodium thiosulfate 1%, sodium hydroxide 0.5%, diethylene triamine 1%, and the rest is deionized water.

[0127] A preparation method of the chemical absorption solution for removing methyl iodide according to the present comparison example, the steps of the method are as follows:

[0128] Sodium thiosulfate, sodium hydroxide and diethylene triamine are sequentially added to deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0129] Performance test:

[0130] The chemical absorption solution according to the present comparison example is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test results show that the absorption efficiency of the chemical absorption solution according to the present comparison example for methyl iodide in sample gas can reach 41%.

[0131] Comparison Example 4

[0132] A chemical absorption solution for removing methyl iodide, in which the total mass of raw materials of the chemical absorption solution is 100%, the components and their mass fractions are as follows:

[0133] Sodium thiosulfate 1%, octyltrimethylammonium chloride 1%, sodium hydroxide 0.5%, and the rest is deionized water.

[0134] A preparation method of the chemical absorption solution for removing methyl iodide according to the present comparative example, the steps of the method are as follows:

[0135] Sodium thiosulfate, sodium hydroxide and octyltrimethylammonium chloride are sequentially added into deionized water, and stirred until each component is completely dissolved and uniformly mixed to obtain a chemical absorption solution for removing methyl iodide.

[0136] Performance test:

[0137] The chemical absorption solution according to the present comparative example is used to absorb methyl iodide in sample gas, the ratio of the mass (kg) of the chemical absorption solution to the concentration (mg / m 3 ) of methyl iodide in sample gas is 1:1; the absorption pressure is normal pressure, and the absorption temperature is 80°C. The test result shows that the absorption efficiency of the chemical absorption solution according to Comparative Example 4 for methyl iodide in sample gas can reach 31%.

[0138] According to the test results of Examples 1-12 and Comparative Examples 1-4, the chemical absorption solution according to the present application can efficiently remove methyl iodide in gas phase.

[0139] The scope of the present application is not limited to this, and those skilled in the art should understand that any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application all fall within the protection scope and disclosure scope of the present application.

Claims

1. A chemical absorbent for removing methyl iodine, characterized in that: Based on the total mass of the chemical absorption liquid raw material being 100%, the individual components and their mass fractions are as follows: The remainder is water; Long-chain alkyl trimethyl ammonium halide salts have more than 8 long-chain carbon atoms.

2. The chemical absorption solution for removing methyl iodine according to claim 1, characterized in that: The halogenation in the long-chain alkyltrimethyl ammonium halide salt is chlorination or bromination, that is, the long-chain alkyltrimethyl ammonium halide salt is a long-chain alkyltrimethyl ammonium chloride salt or a long-chain alkyltrimethyl ammonium bromide salt.

3. The chemical absorption solution for removing methyl iodine according to claim 2, characterized in that: The long-chain alkyl trimethyl ammonium halide salts are hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, or octadecyltrimethylammonium chloride.

4. A chemical absorption solution for removing methyl iodine according to any one of claims 1 to 3, characterized in that: Polyethylene polyamine is at least one of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

5. A method for preparing a chemical absorption solution for removing methyl iodine as described in any one of claims 1 to 4, characterized in that: Sodium thiosulfate and sodium hydroxide are first dissolved in water, and then polyethylene polyamine and long-chain alkyl trimethyl ammonium halide are added in sequence. The mixture is stirred until all components are completely dissolved and mixed evenly to prepare a chemical absorbent for removing methyl iodine. When the mass fraction of polyethylene polyamine and / or sodium hydroxide is 0%, substances with a mass fraction of 0% do not need to be added.

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