Method for removing reactive impurities in a noble gas

Abstract

The present application relates to the field of gas purification, in particular to a method for removing reactive impurities in rare gas, the method comprising the following steps: (S.1) catalytically oxidizing industrial-grade rare gas so that the reducing impurity gas therein is oxidized; (S.2) passing the rare gas treated by catalytic oxidation into an adsorption tower filled with impurity gas adsorbents containing oxygen adsorption units and carbon dioxide adsorption units for adsorption. Through the method in the present application, various reactive impurities in the rare gas can be effectively removed, and the purity of the rare gas is effectively improved. The adsorption purification method in the present application is simple in steps, low in cost, and is conducive to large-scale industrial application.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas purification, in particular to a method for removing reactive impurities in rare gas. BACKGROUND

[0002] Electronic gas is widely used in ion implantation, etching, vapor deposition, doping and other processes in the process of electronic product manufacturing, and is called the "food" and "source" of integrated circuit, liquid crystal panel, LED and photovoltaic materials. The performance of electronic semiconductor devices is closely related to the quality of electronic gas, so electronic gas is also called the "blood" of semiconductor manufacturing.

[0003] Electronic-grade rare gas is a key type of electronic gas, which plays an important role in the field of electronic semiconductors (such as lithography process and semiconductor growth process). The purity and quality stability of electronic-grade rare gas are the highest in the application process of electronic-grade rare gas in the field of electronic semiconductors. The process complexity and difficulty will be significantly improved with each N increase in the purity of electronic-grade rare gas and each order of magnitude decrease in the concentration of particles and metal impurities. If the purity or clarity of electronic-grade rare gas does not meet the standards, it will cause the quality of downstream products to be substandard, or it will spread pollution throughout the product line, resulting in the complete scrapping of products.

[0004] Electronic gas (laser gas) for lithography is used to generate light sources for lithography machines. Most of the lithography gas is rare gas, or a mixture of rare gas and fluorine. This mixture will form a plasma after being excited at high pressure. In this process, due to electron transition, fixed wavelength light will be generated. The wavelength of the light is directly related to the proportion of the mixer and the voltage. The excited light will generate the light source of the lithography machine after aggregation and filtering, and then the complex light path will be used for photolithography of silicon wafers. If other impurity gases are contained in the rare gas, it will cause the proportioning of the lithography gas to deviate, which will directly cause the wavelength of the light source of the lithography machine to change, ultimately causing the photolithography line width to deviate.

[0005] In the process of semiconductor production, rare gas is also commonly used for purging of crystal silicon in the growth process of crystal silicon, so that the purity of the obtained crystal silicon is higher. Once the rare gas contains reactive impurities, these reactive impurities are easy to react with the crystal silicon, thereby contaminating the obtained crystal silicon.

[0006] The reactive impurities in the rare gas usually include hydrogen, carbon monoxide, organic hydrocarbon gas and oxygen. In the prior art, liquefaction fractionation and physical adsorption are often used for purification. However, this method has the problem of poor purification effect, and also has the defect of large energy consumption in the purification process. SUMMARY

[0007] The present application is to overcome the defects that the reactive impurities in the rare gas are difficult to remove in the prior art, and provides a method for removing the reactive impurities in the rare gas to overcome the above shortcomings.

[0008] To achieve the above-mentioned application purposes, the present application is realized by the following technical solutions:

[0009] In the first aspect, the present application first provides a method for removing the reactive impurities in the rare gas, comprising the following steps:

[0010] (S.1) catalytically oxidizing the industrial-grade rare gas, so that the reducing impurity gas therein is oxidized;

[0011] (S.2) passing the rare gas after the catalytic oxidation treatment into the adsorption tower containing the impurity gas adsorbent for adsorption, and after the adsorption is completed, deep cooling treatment is performed to obtain the purified rare gas;

[0012] The impurity gas adsorbent in the step (S.2) comprises a polymer unit;

[0013] and an oxygen adsorption unit and a carbon dioxide adsorption unit grafted to the polymer unit;

[0014] The oxygen adsorption unit comprises a diene alcohol having a reducing property, a conjugated double bond structure or a phenolic structure;

[0015] The carbon dioxide adsorption unit is an amino acid residue comprising an amino group.

[0016] The purification step of the rare gas in the present application mainly comprises two steps of catalytic oxidation and chemical adsorption. In the catalytic oxidation step, the reducing impurities doped in the rare gas can be oxidized, so as to include the oxidation of hydrogen, carbon monoxide and organic hydrocarbon gas and other reducing gases, and finally water and carbon dioxide are obtained. Therefore, after the catalytic oxidation, the rare gas only contains reactive impurities such as water, carbon dioxide and oxygen, thereby greatly simplifying the composition ratio of the internal impurities in the rare gas.

[0017] After the catalytic oxidation, the rare gas containing reactive impurities such as water, carbon dioxide and oxygen is subjected to chemical adsorption, and in step (2), the rare gas is only needed to be passed into the adsorption tower containing the impurity gas adsorbent for adsorption, so as to adsorb the carbon dioxide and oxygen therein, and the remaining water can be removed by deep cooling treatment, and finally the rare gas with low impurity content and dryness is obtained.

[0018] For the impurity gas adsorbent, the prior art usually uses molecular sieve or activated carbon to adsorb the impurity gas in the rare gas, however, the molecular sieve or activated carbon is simple physical adsorption, the adsorption effect of which on the impurity gas is poor, and the problem of desorption is prone to occur, resulting in poor purification effect.

[0019] Therefore, the present application adopts chemical adsorption means to simultaneously adsorb carbon dioxide and oxygen with different properties in one adsorption process in view of the above problems existing in the conventional physical adsorption.

[0020] The adsorption principle of the impurity gas adsorbent in the present application is as follows:

[0021] Firstly, for oxygen, the adsorption of the impurity gas adsorbent in the present application on oxygen is mainly based on the oxygen adsorption unit grafted on the polymer unit, which contains diene alcohol, conjugated double bond structure or phenolic structure. These structures are very sensitive to oxygen, and when the oxygen impurity in the rare gas contacts the oxygen adsorption unit, it can react with the oxygen adsorption unit immediately, thereby effectively reducing the content of the oxygen impurity in the rare gas.

[0022] Secondly, for the adsorption of carbon dioxide, the prior art usually uses metal oxide, metal hydroxide or lithium-based adsorbent to adsorb carbon dioxide, but the adsorption temperature required by the above adsorbent in the process of adsorbing carbon dioxide is too high. For example, the capture amount of magnesium oxide solid particles for carbon dioxide is only 0.43 mmol / g at 200℃, and the adsorption temperature of lithium-based adsorbent is generally higher than 400℃. There is also a precedent in the prior art that liquid ammonia is used to treat carbon dioxide, but ammonia vapor in the liquid ammonia adsorbent is also easy to enter the rare gas, thereby polluting the rare gas after adsorption.

[0023] Therefore, the present application first includes the amino acid residue containing amino grafted on the polymer unit in the carbon dioxide adsorption unit of the impurity gas adsorbent in view of the above deficiencies, which can bring the following beneficial effects:

[0024] (1) The amino contained in the carbon dioxide adsorption unit is alkaline, and carbon dioxide is acidic, which belongs to acid-base reaction in the reaction process, thereby greatly reducing the difficulty of the reaction and facilitating the continuous forward reaction;

[0025] (2) The amino is fixed in the polymer unit in the present application, so that the ammonia molecule will not volatilize into the rare gas during the adsorption process, thereby polluting the rare gas;

[0026] (3) The carbon dioxide adsorption unit in the application contains amino acid residues, and the amino acid residues contain carbonyl groups, which have good affinity for carbon dioxide in noble gas, and are beneficial to attracting carbon dioxide, thereby prolonging the contact time of carbon dioxide and the impurity gas adsorbent, and further improving the adsorption effect of amino on carbon dioxide;

[0027] (4) The carbon dioxide adsorption unit in the application contains amino groups, and after reaction with carbon dioxide, it forms carbamic acid structure, which can form hydrogen bonds with impurity water in noble gas, so after chemical adsorption of carbon dioxide, it can also have the effect of physical adsorption of water in noble gas.

[0028] Therefore, after the noble gas in the application is adsorbed and purified in the adsorption tower containing the impurity gas adsorbent, the purity of the noble gas is greatly improved, thereby effectively meeting the purity requirements of noble gas in the field of electronic semiconductors.

[0029] As preferred, the catalytic oxidation step in step (S.1) is as follows:

[0030] The first filler containing copper oxide is filled into the catalytic oxidation tower, and the filler is heated to temperature T1, and industrial noble gas is introduced into the catalytic oxidation tower, so that the reducing impurity gas therein reacts with the filler at temperature T1, and the catalytic oxidation step is completed.

[0031] In the prior art, a certain amount of oxygen is usually continuously introduced into the noble gas during the catalytic oxidation of the reducing gas, so that the reducing gas doped therein is catalytically oxidized by the oxygen. However, this method has the following technical difficulties. First, the reducing impurities in each batch of noble gas to be treated need to be determined before catalytic oxidation, so that the amount of oxygen introduced is reasonably configured. This process is relatively cumbersome. Second, since the noble gas in the application is an industrial noble gas, the content of reducing impurities therein is relatively low, so the preparation of oxygen is more precise and difficult. If the preparation is not proper, the content of reducing gas impurities will not be reduced, and the content of oxygen impurities will be increased.

[0032] In the application, copper oxide is directly used as an oxidizing agent. After the noble gas is introduced into the copper oxide, the reducing gas therein can react with the copper oxide at high temperature, for example, hydrogen can react with the copper oxide to generate water and elemental copper, carbon monoxide can react with the copper oxide to generate carbon dioxide and elemental copper, and organic hydrocarbon gas can react with the copper oxide to generate carbon dioxide, water and elemental copper. Therefore, the application can effectively treat the reducing gas in the noble gas without introducing other impurities, and simplifies the composition ratio of the internal impurities in the noble gas.

[0033] Meanwhile, after the copper oxide catalytic oxidation for a certain time, the newly formed elemental copper can also react with oxygen, thereby continuing to adsorb the copper oxide, and the newly formed copper oxide can further participate in the reaction with the reducing gas, thereby effectively reducing the oxygen content in the rare gas.

[0034] As a preference, the catalytic oxidation tower further comprises a second filler composed of manganese, iron, cobalt or silver oxides.

[0035] In the present application, the second filler in the catalytic oxidation tower can effectively promote the reaction between the copper oxide and the reducing gas as a catalyst, thereby reducing the reaction temperature.

[0036] As a preference, the mass ratio of the second filler to the first filler is 0.05-1%.

[0037] As a preference, the temperature T1 is 300-450℃.

[0038] As a preference, the preparation method of the impurity gas adsorbent in step (S.2) is as follows:

[0039] (1) Preparation of monomer 1 containing an oxygen adsorption unit:

[0040] The compound containing a hydroxyl group and an oxygen adsorption unit is reacted with acryloyl chloride to obtain intermediate I;

[0041] Intermediate I is reacted with a silane containing both silicon hydride and alkoxy to undergo a silicon hydride addition reaction to obtain monomer I containing an oxygen adsorption unit;

[0042] (2) Preparation of monomer II containing a carbon dioxide adsorption unit:

[0043] The carboxyl group in the amino acid is acylated with carboxyl chloride, and then reacted with hydroxyethyl acrylate to obtain intermediate II;

[0044] Intermediate II is reacted with a silane containing both silicon hydride and alkoxy to undergo a silicon hydride addition reaction to obtain monomer II containing a carbon dioxide adsorption unit;

[0045] (3) Monomer I and monomer II are mixed and hydrolyzed to obtain a silica aerogel with an oxygen adsorption unit and a carbon dioxide adsorption unit, which is crushed to obtain the impurity gas adsorbent.

[0046] As a preference, the compound containing a hydroxyl group and an oxygen adsorption unit in step (1) includes any one or a combination of more than one of retinol, vitamin C, vitamin E, and dopamine.

[0047] As a preference, the amino acid includes at least two amino groups.

[0048] As a preference, the amino acid includes any one or a combination of lysine, arginine, glutamine, and asparagine.

[0049] As a preference, the pressure of the adsorption tower in the step (S.2) is 0.1-0.5 MPa, and the adsorption temperature is 50-80℃.

[0050] Therefore, the present application has the following beneficial effects:

[0051] (1) Through the method in the present application, various reactive impurities in the rare gas can be effectively removed, and the purity of the rare gas is effectively improved;

[0052] (2) The present application mainly uses chemical adsorption, supplemented by physical adsorption, and the adsorption of various reactive impurities in the rare gas is more excellent;

[0053] (3) The adsorption purification method in the present application has simple steps and low cost, which is conducive to large-scale industrial application. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 It is a photo of the silica aerogel block obtained by preliminary crushing in the preparation of the impurity gas adsorbent I in the present application.

[0055] Figure 2 It is an electron microscope photo of the impurity gas adsorbent I. DETAILED DESCRIPTION

[0056] The present application will be further described below in combination with the drawings and specific examples in the specification. Those skilled in the art will be able to implement the present application based on these descriptions. In addition, the examples of the present application involved in the following description are generally only a part of the examples of the present application, not all the examples. Therefore, based on the examples in the present application, all other examples obtained by those skilled in the art without making creative efforts shall belong to the scope of protection of the present application.

[0057] Preparation of monomer I

[0058] Preparation of monomer (I-I): Under nitrogen protection, retinol 2.86 g (10 mmol) was dissolved in 50 ml of dichloromethane, and then a mixed solution of trimethoxysilyl chloride 1.57 g (10 mmol) and 20 ml of dichloromethane was added dropwise at-10℃. After 3h of reaction, the solvent was evaporated to obtain the crude monomer (I-I), which was purified by column to obtain the monomer (I-I). The reaction formula is shown in the following formula (1):

[0059]

[0060] Preparation of monomer (I-II): α-Tocopherol 4.24 g (10 mmol) was dissolved in 50 ml of dichloromethane under nitrogen protection, and then a mixed solution of trimethoxychlorosilane 1.57 g (10 mmol) and 20 ml of dichloromethane was added dropwise thereto at -10°C. After reaction for 3 hours, the solvent was evaporated to obtain a crude monomer (I-II), and the monomer (I-II) was obtained after purification by column chromatography. The reaction formula is shown in the following formula (2):

[0061]

[0062] Preparation of monomer (I-II): α-Tocopherol 4.24 g (10 mmol) was dissolved in 50 ml of dichloromethane under nitrogen protection, and then a mixed solution of trimethoxychlorosilane 1.57 g (10 mmol) and 20 ml of dichloromethane was added dropwise thereto at -10°C. After reaction for 3 hours, the solvent was evaporated to obtain a crude monomer (I-II), and the monomer (I-II) was obtained after purification by column chromatography. The reaction formula is shown in the following formula (2):

[0063]

[0064] Preparation of monomer (I-II): α-Tocopherol 4.24 g (10 mmol) was dissolved in 50 ml of dichloromethane under nitrogen protection, and then a mixed solution of trimethoxychlorosilane 1.57 g (10 mmol) and 20 ml of dichloromethane was added dropwise thereto at -10°C. After reaction for 3 hours, the solvent was evaporated to obtain a crude monomer (I-II), and the monomer (I-II) was obtained after purification by column chromatography. The reaction formula is shown in the following formula (2):

[0065]

[0066] Preparation of monomer (I-II): α-Tocopherol 4.24 g (10 mmol) was dissolved in 50 ml of dichloromethane under nitrogen protection, and then a mixed solution of trimethoxychlorosilane 1.57 g (10 mmol) and 20 ml of dichloromethane was added dropwise thereto at -10°C. After reaction for 3 hours, the solvent was evaporated to obtain a crude monomer (I-II), and the monomer (I-II) was obtained after purification by column chromatography. The reaction formula is shown in the following formula (2):

[0067] Preparation of monomer (II-I):

[0068] (1) Protection of amino group: Ethyl trifluoroacetate (11 mmol) was dissolved in 10 ml of anhydrous diethyl ether under nitrogen protection, and stirred at 0°C for 10 minutes. Lysine (5 mmol) was added, and the reaction mixture was stirred at the same temperature for 1 hour. After removal of the solvent, the residue was purified by flash column chromatography to obtain lysine protected by amino group. The reaction formula is shown in the following formula (5):

[0069] (2) Under nitrogen, dissolve lysine with protected amino group (3.38 g 10 mmol) in 20 mL dichloromethane, add oxalyl chloride (4.25 mL, 48.40 mmol), stir the resulting mixture at room temperature for 30 minutes, then slowly heat the mixture under reflux for 30 minutes. Concentrate the mixture under vacuum, dissolve the residue in THF, concentrate the solution under vacuum again to obtain lysine with protected amino group and acyl chloride, which is shown in the following formula (6):

[0070]

[0071] (3) Under nitrogen, dissolve hydroxyethyl acrylate (1.16 g 10 mmol) in 30 mL dichloromethane, then at -10°C, drop into the mixture a mixture containing lysine with protected amino group and acyl chloride (3.56 g 10 mmol) and 20 mL dichloromethane, after 3 hours of reaction, evaporate the solvent to obtain the crude intermediate (II-I), purify by column to obtain intermediate (II-I), which is shown in the following formula (7):

[0072]

[0073] (4) Under nitrogen, dissolve intermediate (II-I) (4.36 g 10 mmol) in 5% K2CO3 MeOH / H2O (50 mL) and stir the solution at 23°C for 4 hours. Add H2O (3 mL), saturate with NaCl solution, then extract with CH2Cl2 (5 x 15 mL). Dry (Na2SO4) the combined organic extracts and concentrate under reduced pressure to obtain intermediate (II-II), which is shown in the following formula (8):

[0074]

[0075] (5) Under nitrogen, dissolve intermediate (II-II) (2.44 g 10 mmol) and trimethoxysilane (1.46 g 12 mmol) in 20 mL toluene, add 0.1 g Karstedt catalyst (platinum catalyst) to the mixture, after 5 hours of reflux reaction, add 1 g activated carbon to the reaction solution, stir at room temperature for 1 hour for adsorption, then filter to obtain the filtrate, evaporate the solvent in the filtrate to obtain monomer (II-I), which is shown in the following formula (8):

[0076]

[0077] Preparation of monomer (II-II): The preparation method of monomer (II-II) is similar to that of monomer (II-I), the difference is that lysine is replaced by glutamine, and the structure of monomer (II-II) is shown in the following formula (9):

[0078]

[0079] Preparation of monomer (II-III): the preparation method of monomer (II-III) is similar to that of monomer (II-I), except that lysine is replaced by alanine, and the structure of monomer (II-III) is shown in the following formula (10):

[0080]

[0081] Preparation of impurity gas adsorbent

[0082] Preparation of impurity gas adsorbent I:

[0083] Under the protection of nitrogen, the monomer (I-I), the monomer (II-I) and the tetraethyl orthosilicate are mixed uniformly according to the mass ratio of 3:3:4 to obtain a mixed monomer;

[0084] The raw materials are weighed according to the mass ratio: ethanol: mixed monomer: deionized water: ammonia water = 4:1:1:0.16.

[0085] According to the proportion, the ethanol, the ethyl orthosilicate and the deionized water are added into the beaker in sequence, and then mixed and stirred for 90 min. After being mixed uniformly, it is left to stand for 24 h, so that the mixed monomer is fully hydrolyzed. Then, the stirring is started again for 60 min. The pH value is adjusted to 6-7 by using ammonia water. Then, it is poured into a sealed container, so as to form a wet gel. After aging, it is taken out of the mold, soaked in n-hexane, so as to replace the water and ethanol in the wet gel. Subsequently, the wet gel is dried at normal temperature and pressure for two days, and then placed in a vacuum drying oven. The initial temperature is 30℃, and the temperature is increased by 5℃ per hour until the temperature is increased to 70℃. The temperature is kept at 70℃ for 24 h. After preliminary crushing, the silica aerogel block (as shown in Figure 1 ) is obtained. After being crushed again and passed through a 500-mesh sieve, the impurity gas adsorbent I (the electron microscope image is as shown in Figure 2 ) is obtained.

[0086] Preparation of impurity gas adsorbent II:

[0087] The preparation method of the impurity gas adsorbent II is the same as that of the impurity gas adsorbent I, except that the mixed monomer is obtained by mixing the monomer (II), the monomer (II-I) and the tetraethyl orthosilicate.

[0088] Preparation of impurity gas adsorbent III:

[0089] The preparation method of the impurity gas adsorbent III is the same as that of the impurity gas adsorbent I, except that the mixed monomer is obtained by mixing the monomer (I-III), the monomer (II-I) and the tetraethyl orthosilicate.

[0090] Preparation of impurity gas adsorbent IV:

[0091] The impurity gas adsorbent III is prepared in the same way as the impurity gas adsorbent I, except that the mixed monomers are obtained by mixing monomer (I-IV), monomer (II-I) and tetraethyl orthosilicate.

[0092] Preparation of the impurity gas adsorbent V:

[0093] The impurity gas adsorbent V is prepared in the same way as the impurity gas adsorbent I, except that the mixed monomers are obtained by mixing monomer (I-I), monomer (II-II) and tetraethyl orthosilicate.

[0094] Preparation of the impurity gas adsorbent VI:

[0095] The impurity gas adsorbent VI is prepared in the same way as the impurity gas adsorbent I, except that the mixed monomers are obtained by mixing monomer (I-I), monomer (II-III) and tetraethyl orthosilicate.

[0096] Example 1

[0097] The method for removing reactive impurities in argon gas comprises the following steps:

[0098] (S.1) The copper oxide (first filler) is filled into a catalytic oxidation tower, and the filler is heated to a temperature of 450°C. Industrial-grade helium (4N) is introduced into the catalytic oxidation tower, and the supply flow rate of the industrial-grade argon is 0.5 Nm 3 / h, and the pressure is 0.5 MPa. The reducing impurity gas therein is allowed to react with the first filler at a temperature of 450°C, and the catalytic oxidation step is completed, so that the reducing impurity gas therein is oxidized.

[0099] (S.2) The argon gas after the catalytic oxidation treatment is introduced into an adsorption tower containing the impurity gas adsorbent I for adsorption. The supply flow rate of the argon gas is 1 Nm 3 / h, the pressure is 0.5 MPa, and the adsorption temperature is 75°C. After the adsorption is completed, deep cooling treatment is performed by using a cold well to remove the residual water vapor, and the purified argon gas is obtained.

[0100] Example 2

[0101] The method for removing reactive impurities in argon gas comprises the following steps:

[0102] (S.1) The copper oxide (first filler) is filled into a catalytic oxidation tower, and the filler is heated to a temperature of 450°C. Industrial-grade helium (4N) is introduced into the catalytic oxidation tower, and the supply flow rate of the industrial-grade argon is 0.5 Nm 3 / h, and the pressure is 0.5 MPa. The reducing impurity gas therein is allowed to react with the first filler at a temperature of 450°C, and the catalytic oxidation step is completed, so that the reducing impurity gas therein is oxidized.

[0103] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent II for adsorption, the argon gas supply flow rate is 1 Nm 3 / h, the pressure is 0.3 MPa, the adsorption temperature is 75°C, after the adsorption is completed, the remaining water vapor is removed through the cold well for cryogenic treatment, and the purified argon gas is obtained.

[0104] Example 3

[0105] The method for removing the reactive impurities in the argon gas comprises the following steps:

[0106] (S.1) The copper oxide (first filler) is filled into the catalytic oxidation tower, and the filler is heated to a temperature of 450°C, the industrial-grade argon gas (4N) is introduced into the catalytic oxidation tower, the supply flow rate of the industrial-grade argon gas is 0.5 Nm 3 / h, the pressure is 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, the catalytic oxidation step is completed, and the reducing impurity gas therein is oxidized;

[0107] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent III for adsorption, the argon gas supply flow rate is 1 Nm 3 / h, the pressure is 0.3 MPa, the adsorption temperature is 75°C, after the adsorption is completed, the remaining water vapor is removed through the cold well for cryogenic treatment, and the purified argon gas is obtained.

[0108] Example 4

[0109] The method for removing the reactive impurities in the argon gas comprises the following steps:

[0110] (S.1) The copper oxide (first filler) is filled into the catalytic oxidation tower, and the filler is heated to a temperature of 450°C, the industrial-grade argon gas (4N) is introduced into the catalytic oxidation tower, the supply flow rate of the industrial-grade argon gas is 0.5 Nm 3 / h, the pressure is 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, the catalytic oxidation step is completed, and the reducing impurity gas therein is oxidized;

[0111] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent IV for adsorption, the argon gas supply flow rate is 1 Nm 3 / h, the pressure is 0.3 MPa, the adsorption temperature is 75°C, after the adsorption is completed, the remaining water vapor is removed through the cold well for cryogenic treatment, and the purified argon gas is obtained.

[0112] Example 5

[0113] The method for removing the reactive impurities in the argon gas comprises the following steps:

[0114] (S.1) The first filler containing copper oxide is filled into the catalytic oxidation tower, and the filler is heated to a temperature of 450°C. Industrial-grade argon (4N) is introduced into the catalytic oxidation tower at a flow rate of 0.5 Nm 3 / h, and the pressure is 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, and the catalytic oxidation step is completed, so that the reducing impurity gas therein is oxidized.

[0115] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent V for adsorption, and the argon gas is supplied at a flow rate of 1 Nm 3 / h, the pressure is 0.3 MPa, and the adsorption temperature is 75°C. After the adsorption is completed, deep cooling treatment is performed by a cold well to remove residual water vapor, and purified argon gas is obtained.

[0116] Example 6

[0117] A method for removing reactive impurities in argon gas, comprising the following steps:

[0118] (S.1) The first filler containing copper oxide is filled into the catalytic oxidation tower, and the filler is heated to a temperature of 450°C. Industrial-grade argon (4N) is introduced into the catalytic oxidation tower at a flow rate of 0.5 Nm 3 / h, and the pressure is 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, and the catalytic oxidation step is completed, so that the reducing impurity gas therein is oxidized.

[0119] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent V for adsorption, and the argon gas is supplied at a flow rate of 1 Nm 3 / h, the pressure is 0.3 MPa, and the adsorption temperature is 75°C. After the adsorption is completed, deep cooling treatment is performed by a cold well to remove residual water vapor, and purified argon gas is obtained.

[0120] Example 7

[0121] A method for removing reactive impurities in argon gas, comprising the following steps:

[0122] (S.1) The first filler containing copper oxide and the second filler containing manganese dioxide in a mass ratio of 0.05% of the first filler are filled into the catalytic oxidation tower, and the filler is heated to a temperature of 320°C. Industrial-grade argon (4N) is introduced into the catalytic oxidation tower at a flow rate of 0.5 Nm 3 / h, at a pressure of 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, completing the catalytic oxidation step, so that the reducing impurity gas therein is oxidized;

[0123] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent I to be adsorbed, the argon gas supply flow rate is 1 Nm 3 / h, at a pressure of 0.3 MPa, and an adsorption temperature of 75°C, after the adsorption is completed, deep cooling treatment is carried out through the cold well to remove the residual water vapor, and the purified argon gas is obtained.

[0124] Example 8

[0125] The method for removing the reactive impurities in the argon gas comprises the following steps:

[0126] (S.1) The copper oxide (first filler) and silver oxide (second filler) accounting for 0.05% of the mass of the first filler are filled into the catalytic oxidation tower, and the filler is heated to a temperature of 350°C, and the industrial-grade argon gas (4N) is introduced into the catalytic oxidation tower, the supply flow rate of the industrial-grade argon gas is 0.5 Nm 3 / h, at a pressure of 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, completing the catalytic oxidation step, so that the reducing impurity gas therein is oxidized;

[0127] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent I to be adsorbed, the argon gas supply flow rate is 1 Nm 3 / h, at a pressure of 0.1 MPa, and an adsorption temperature of 80°C, after the adsorption is completed, deep cooling treatment is carried out through the cold well to remove the residual water vapor, and the purified argon gas is obtained.

[0128] Example 9

[0129] The method for removing the reactive impurities in the argon gas comprises the following steps:

[0130] (S.1) The copper oxide (first filler) and manganese dioxide (second filler) accounting for 0.1% of the mass of the first filler are filled into the catalytic oxidation tower, and the filler is heated to a temperature of 300°C, and the industrial-grade argon gas (4N) is introduced into the catalytic oxidation tower, the supply flow rate of the industrial-grade argon gas is 0.5 Nm 3 / h, at a pressure of 0.5 MPa, so that the reducing impurity gas therein reacts with the first filler at a temperature of 450°C, completing the catalytic oxidation step, so that the reducing impurity gas therein is oxidized;

[0131] (S.2) The argon gas after the catalytic oxidation treatment is introduced into the adsorption tower containing the impurity gas adsorbent I to be adsorbed, the argon gas supply flow rate is 1 Nm3 / h, the pressure was 0.5 MPa, and the adsorption temperature was 50°C. After the adsorption was completed, the residual water vapor was removed by cryogenic treatment using a cold well, and purified argon gas was obtained.

[0132] Example 10

[0133] A method for removing reactive impurities from krypton gas includes the following steps:

[0134] (S.1) Copper oxide (first packing) and silver oxide (second packing) in a mass ratio of 0.05% to the first packing were filled into a catalytic oxidation tower, and the packing was heated to a temperature of 350°C. Industrial-grade krypton gas (5N) was supplied to the catalytic oxidation tower at a flow rate of 0.5 Nm 3 / h, and the pressure was 0.5 MPa. The reducing impurity gas therein reacted with the first packing at a temperature of 450°C, and the catalytic oxidation step was completed, so that the reducing impurity gas therein was oxidized.

[0135] (S.2) The krypton gas subjected to the catalytic oxidation treatment was supplied to an adsorption tower containing impurity gas adsorbent I, and was adsorbed at a flow rate of 1 Nm 3 / h, and the pressure was 0.3 MPa. The adsorption temperature was 75°C, and after the adsorption was completed, the residual water vapor was removed by cryogenic treatment using a cold well, and purified krypton gas was obtained.

[0136] Example 11

[0137] A method for removing reactive impurities from xenon gas includes the following steps:

[0138] (S.1) Copper oxide (first packing) and manganese dioxide (second packing) in a mass ratio of 0.05% to the first packing were filled into a catalytic oxidation tower, and the packing was heated to a temperature of 320°C. Industrial-grade xenon gas (4N) was supplied to the catalytic oxidation tower at a flow rate of 0.5 Nm 3 / h, and the pressure was 0.5 MPa. The reducing impurity gas therein reacted with the first packing at a temperature of 450°C, and the catalytic oxidation step was completed, so that the reducing impurity gas therein was oxidized.

[0139] (S.2) The xenon gas subjected to the catalytic oxidation treatment was supplied to an adsorption tower containing impurity gas adsorbent I, and was adsorbed at a flow rate of 1 Nm 3 / h, and the pressure was 0.3 MPa. The adsorption temperature was 75°C, and after the adsorption was completed, the residual water vapor was removed by cryogenic treatment using a cold well, and purified xenon gas was obtained.

[0140] The contents of impurity gases in the rare gases purified in Examples 1 to 11 are shown in Table 1 below.

[0141] Table 1

[0142]

[0143] From the data in the above table, it can be seen that the method in the present application can play a good adsorption effect on the reactivity impurities in various types of industrial-grade rare gases, and after the impurity removal treatment in the present application, the content of the reactivity impurities in the rare gases is greatly reduced from ppm level to ppb level, which can meet the requirements of the electronic semiconductor field (such as photolithography process and semiconductor growth process) for the purity and quality stability of the electronic-grade rare gases.

[0144] In terms of details, in step (S.1), a certain amount of second filler composed of manganese, iron, cobalt or silver oxides is doped in the first filler, which can play a good catalytic effect on the reducing impurities in the rare gases, so that they are more easily oxidized, thereby greatly simplifying the composition ratio of the internal impurities in the rare gases.

[0145] Meanwhile, by comparing Example 6 with Examples 1-5, it can be seen that the number of amino groups in the monomer II in the impurity gas adsorbent has a more obvious relationship with the adsorption of carbon dioxide, and when a monomer containing multiple amino groups is selected, it can effectively improve the adsorption effect of carbon dioxide.

Claims

1. A method for removing reactive impurities in a rare gas, characterized by, The method comprises the following steps: (S.1) catalytically oxidizing industrial-grade noble gas so that reducing impurity gas therein is oxidized; (S.2) passing the noble gas after the catalytic oxidation treatment into an adsorption tower containing an impurity gas adsorbent for adsorption, and after the adsorption is completed, performing cryogenic treatment to obtain purified noble gas; The impurity gas adsorbent in step (S.2) comprises a polymer unit; and an oxygen adsorption unit and a carbon dioxide adsorption unit grafted to the side chain of the polymer unit; The oxygen adsorption unit comprises a diene alcohol, a conjugated double bond structure or a phenolic structure with reducing property; The carbon dioxide adsorption unit is an amino acid residue comprising an amino group; The preparation method of the impurity gas adsorbent in step (S.2) is as follows: (1) reacting a compound containing a hydroxyl group and an oxygen adsorption unit with a silane containing an alkoxy group to obtain a monomer I containing an oxygen adsorption unit; (2) acyl chlorinating a carboxyl group in an amino acid, then reacting with hydroxyethyl acrylate to obtain an intermediate II, and then reacting the intermediate II with a silane containing both silicon hydrogen and an alkoxy group to undergo a silicon hydrogen addition reaction to obtain a monomer II containing a carbon dioxide adsorption unit; (3) mixing and hydrolyzing the monomer I and the monomer II to obtain a silica aerogel with an oxygen adsorption unit and a carbon dioxide adsorption unit, and crushing the silica aerogel to obtain the impurity gas adsorbent.

2. The method for removing reactive impurities in noble gas according to claim 1, wherein the catalytic oxidation step in step (S.1) is as follows: a first filler containing copper oxide is filled into a catalytic oxidation tower, and the filler is heated to a temperature T1, and industrial-grade noble gas is passed into the catalytic oxidation tower, so that the reducing impurity gas therein reacts with the first filler at the temperature T1 to complete the catalytic oxidation step.

3. The method for removing reactive impurities in noble gas according to claim 2, wherein the catalytic oxidation tower further comprises at least a second filler composed of oxides of manganese, iron, cobalt or silver.

4. The method for removing reactive impurities in noble gas according to claim 3, wherein the mass ratio of the second filler to the first filler is 0.05-1%.

5. The method for removing reactive impurities in noble gas according to claim 2 or 3 or 4, wherein the temperature T1 is 300-450°C.

6. The method for removing reactive impurities in noble gas according to claim 1, wherein the compound containing a hydroxyl group and an oxygen adsorption unit in step (1) comprises any one or a combination of multiple of retinol, vitamin C, vitamin E and dopamine.

7. The method for removing reactive impurities in noble gas according to claim 1, wherein the amino acid comprises at least two amino groups.

8. The method for removing reactive impurities in noble gas according to claim 7, wherein the amino acid comprises any one or a combination of multiple of lysine, arginine, glutamine and asparagine. ​ ​ ​ ​ ​ ​ ​ 9. The method for removing reactive impurities in a noble gas according to Claim 1, wherein the pressure of the adsorption tower in the step (S.2) is 0.1 to 0.5 MPa, and the adsorption temperature is 50 to 80°C.

9. The method for removing reactive impurities in a noble gas according to Claim 1, wherein the pressure of the adsorption tower in the step (S.2) is 0.1 to 0.5 MPa, and the adsorption temperature is 50 to 80°C.

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