Method for removing trace moisture from carbon dioxide

Abstract

Provided is a method for removing trace moisture from carbon dioxide. The method comprises the following steps: firstly uniformly mixing tetrapropylammonium hydroxide with deionized water to obtain solution A; dissolving potassium metaaluminate in solution A to obtain solution B; dropwise adding tetraethyl orthosilicate to solution B, and stirring and mixing to obtain solution C; transferring solution C to a hydrothermal kettle for a reaction for at least 2 hours, taking out the reactant after the reaction is finished, washing the reactant with water, and centrifugally separating and drying the reactant; continuing heating to 550ºC and performing calcination for at least 2 h to obtain K-ZSM-5; preparing an ethanolic solution of potassium ethoxide, infiltrating the K-ZSM-5 with the ethanolic solution of potassium ethoxide, and removing ethanol from the infiltrated K-ZSM-5 under vacuum to obtain an adsorbent; and filling an adsorption column with the adsorbent, introducing carbon dioxide into the adsorption column, and removing water from the carbon dioxide by means of a chemical adsorption method. The adsorbent preparation method disclosed in the present invention is simple and involves readily available materials; high temperature is not required throughout an impurity removal stage; and the impurity removal method is simple and has high efficiency, and the moisture content can be reduced to 20 ppb or less.

Description

A method for removing trace water from carbon dioxide Technical Field

[0001] The present invention relates to the technical field of special gas purification, and in particular to a method for removing trace moisture from carbon dioxide. Background Art

[0002] Due to scCO2's extremely low surface tension, it can clean delicate electronic components without causing damage. Once cleaning or etching is complete, simply release the pressure, and the CO2 evaporates from the microporous structure, leaving no residue, achieving simultaneous etching, cleaning, and drying. Furthermore, CO2 is inexpensive, readily available, non-toxic, chemically stable, and non-flammable, making it considered a safe and environmentally friendly cleaning medium.

[0003] CO2 is a nonpolar solvent with a zero dipole moment. Therefore, CO2 can effectively remove nonpolar and weakly polar organic contaminants from wafers, such as silicones, aliphatic hydrocarbons with small carbon numbers, and oils. The physicochemical properties of scCO2 near its critical point, such as viscosity, diffusion coefficient, and solubility, are highly sensitive to changes in temperature and pressure. Based on these properties, the solubility of some contaminants on the wafer in the scCO2 medium can be controlled by adjusting temperature and pressure. By reducing the pressure, the CO2 can remove the contaminants, achieving the goal of wafer cleaning. However, the solubility of polar substances on the wafer in the scCO2 medium is low, and cosolvents such as propylene carbonate, acetylacetone, and acetic acid are often required to increase their solubility for effective cleaning. When used as a cleaning agent, scCO2 has very high water content requirements, requiring it to be below 50 ppb. However, achieving this level is difficult using conventional adsorption and distillation methods.

[0004] In this regard, the present application provides a method for removing trace moisture in carbon dioxide, which effectively reduces the moisture in carbon dioxide to 20ppb through chemical adsorption, making it suitable for wafer cleaning and selective etching, which is obviously of practical significance.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to provide a method for removing trace moisture in carbon dioxide, by preparing an adsorbent and filling it into an adsorption column, so as to effectively reduce the moisture in carbon dioxide through chemical adsorption.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for removing trace moisture in carbon dioxide, comprising the following steps:

[0008] S1. Preparation of K-ZSM-5: First, tetrapropylammonium hydroxide and deionized water were uniformly mixed to obtain solution A; potassium metaaluminate was dissolved in solution A to obtain solution B; ethyl orthosilicate was dropwise added to solution B, stirred and mixed; solution C was transferred to a hydrothermal autoclave and reacted for at least 2 hours. After the reaction, the reactants were removed, washed with water, centrifuged, and dried; the temperature was continued to rise to 550°C and calcined for at least 2 hours to obtain K-ZSM-5;

[0009] S2. Preparation of adsorbent: preparing an ethanol solution of potassium ethoxide, soaking the K-ZSM-5 prepared in step S1 in the ethanol solution of potassium ethoxide, and removing ethanol from the soaked K-ZSM-5 under vacuum to obtain an adsorbent;

[0010] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0011] Preferably, in step S1, the molar ratio of potassium metaaluminate to tetraethyl orthosilicate added is 1:25-100.

[0012] Preferably, in step S1, the amount of potassium metaaluminate added is 0.005 mol to 0.02 mol, and the amount of ethyl orthosilicate added is 1 mol.

[0013] Preferably, in step S1, the mass ratio of tetrapropylammonium hydroxide to deionized water is 1:1 to 4:1.

[0014] Preferably, in step S1, the specific preparation method of solution C is to dropwise add ethyl orthosilicate into solution B at a rate of 1 mL / min, stirring in an ice-water bath during the process, and continuing stirring for 2 hours after the completion of the dropwise addition to obtain solution C.

[0015] Preferably, in step S1, the temperature of the hydrothermal reaction in the hydrothermal kettle is 150° C. to 190° C., and the time of the hydrothermal reaction is 12 h to 36 h.

[0016] Preferably, in step S1, the specific method of calcination is: continue heating at a heating rate of 1°C / min and calcine at 550°C for 6 hours.

[0017] Preferably, in step S2, the concentration of potassium ethoxide in the ethanol solution of potassium ethoxide is 6% to 24%.

[0018] Preferably, in step S3, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed with water by a 5A molecular sieve, and the water content is 1 ppm.

[0019] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0020] In the above, when the water content of the carbon dioxide after passing through the adsorption column is less than 50 ppb, the adsorption is considered to be completed.

[0021] In the above, the principle that the prepared adsorbent can absorb water is that the microporous structure of ZSM-5 can absorb water; potassium ethanol can react with water to produce potassium hydroxide and ethanol, and ethanol can be adsorbed by the microporous structure of ZSM-5.

[0022] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] 1. The present invention prepares an adsorbent by reacting tetrapropylammonium hydroxide, potassium metaaluminate, and ethyl orthosilicate. By controlling the raw material ratio and hydrothermal reaction conditions, the adsorbent can reduce the water content in carbon dioxide through chemical adsorption to below 20 ppb, ensuring the application of the critical carbon dioxide medium in wafer cleaning and selective etching.

[0024] 2. The preparation method of the adsorbent disclosed in the present invention is simple, the materials are easily available, high temperature is not required for the entire impurity removal stage, the impurity removal method is simple, the efficiency is high, and it is suitable for promotion and use. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0028] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.49 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 170°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0029] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 24% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0030] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0031] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:100.

[0032] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0033] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0034] Example 2

[0035] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0036] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 170°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0037] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 24% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0038] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0039] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0040] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0041] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0042] Example 3

[0043] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0044] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 150°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0045] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 24% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0046] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0047] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0048] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0049] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0050] Example 4

[0051] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0052] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 190°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0053] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 24% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0054] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0055] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0056] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0057] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0058] Example 5

[0059] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0060] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 1.96 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 170°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0061] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 24% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0062] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0063] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:25.

[0064] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0065] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0066] Example 6

[0067] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0068] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 150°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0069] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 6% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0070] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0071] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0072] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0073] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0074] Example 7

[0075] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0076] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 150°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0077] S2. Preparation of adsorbent: A potassium ethoxide ethanol solution with a potassium ethoxide concentration of 12% was prepared, the K-ZSM-5 prepared in step S1 was soaked in the potassium ethoxide ethanol solution, and the ethanol was removed from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0078] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0079] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0080] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0081] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0082] Example 8

[0083] This embodiment relates to a method for removing trace moisture from carbon dioxide, which specifically includes the following steps:

[0084] S1. Preparation of K-ZSM-5: First, 200 g of tetrapropylammonium hydroxide and 50 g of deionized water were mixed uniformly to obtain solution A; 0.98 g of potassium metaaluminate was dissolved in solution A to obtain solution B; 104 g of ethyl orthosilicate was dropwise added to solution B at a rate of 1 mL / min, with stirring in an ice-water bath during the process, and stirring was continued for 2 h after the dropwise addition was completed to obtain a mixed solution C; the mixed solution C was transferred to a 300 mL hydrothermal autoclave and heated at 150°C for 24 h; after the reaction was completed, the reactants were removed, washed with water, centrifuged, and dried at 100°C; the temperature was increased at a rate of 1°C / min and calcined at 550°C for 6 h to obtain K-ZSM-5;

[0085] S2. Preparation of adsorbent: preparing an ethanol solution of potassium ethoxide with a potassium ethoxide concentration of 18%, soaking the K-ZSM-5 prepared in step S1 in the ethanol solution of potassium ethoxide, and removing ethanol from the soaked K-ZSM-5 at 70° C. under vacuum to obtain the adsorbent;

[0086] S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

[0087] In the above, in step S1, the molar ratio of potassium metaaluminate to ethyl orthosilicate added is 1:50.

[0088] In the above, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by 5A molecular sieve and has a moisture content of 1 ppm.

[0089] Preferably, in step S3, the carbon dioxide gas is heated at 200h -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

[0090] The raw material contents and reaction conditions used in Examples 1 to 8 are shown in Table 1 below.

[0091] Table 1

[0092] The carbon dioxide adsorbed by the above-mentioned Examples 1 to 8 was tested respectively, and the test results are shown in Table 2 below.

[0093] Table 2

[0094] It is obvious from the above table that, under the same conditions, the adsorbent prepared with a silicon-aluminum ratio of 50:1 has the best adsorption capacity;

[0095] Under the same conditions, the adsorption capacity of the prepared adsorbent is the best when the hydrothermal reaction temperature is 170℃;

[0096] When other conditions are the same, the adsorbent prepared has the best adsorption capacity when the silicon-aluminum ratio is 50:1;

[0097] When other conditions were the same, the adsorption capacity of the prepared adsorbent was the best when the concentration of potassium ethoxide was 24%.

[0098] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for removing trace moisture from carbon dioxide, characterized in that: The following steps are involved: S1. Preparation of K-ZSM-5: First, tetrapropylammonium hydroxide and deionized water were uniformly mixed to obtain solution A; potassium metaaluminate was dissolved in solution A to obtain solution B; ethyl orthosilicate was dropwise added to solution B, stirred and mixed; solution C was transferred to a hydrothermal autoclave and reacted for at least 2 hours. After the reaction, the reactants were removed, washed with water, centrifuged, and dried; the temperature was continued to rise to 550°C and calcined for at least 2 hours to obtain K-ZSM-5; S2. Preparation of adsorbent: preparing an ethanol solution of potassium ethoxide, soaking the K-ZSM-5 prepared in step S1 in the ethanol solution of potassium ethoxide, and removing ethanol from the soaked K-ZSM-5 under vacuum to obtain an adsorbent; S3. Fill the adsorbent into the adsorption column, pass carbon dioxide into the adsorption column, and remove water from the carbon dioxide using chemical adsorption.

2. The method for removing trace moisture from carbon dioxide according to claim 1, wherein: In step S1, the molar ratio of potassium metaaluminate to tetraethyl orthosilicate is 1:25-100.

3. The method for removing trace moisture from carbon dioxide according to claim 2, wherein: In step S1, the amount of potassium metaaluminate added is 0.005 mol to 0.02 mol, and the amount of ethyl orthosilicate added is 1 mol.

4. The method for removing trace moisture from carbon dioxide according to claim 1, wherein: In step S1, the mass ratio of tetrapropylammonium hydroxide to deionized water is 1:1 to 4:

1.

5. The method for removing trace moisture from carbon dioxide according to claim 1, wherein: In step S1, the specific preparation method of solution C is to dropwise add ethyl orthosilicate into solution B at a rate of 1 mL / min, stirring in an ice-water bath during the process, and continuing stirring for 2 hours after the dropwise addition is completed, thereby obtaining solution C.

6. The method for removing trace moisture from carbon dioxide according to claim 1, wherein: In step S1, the temperature of the hydrothermal reaction in the hydrothermal kettle is 150° C. to 190° C., and the time of the hydrothermal reaction is 12 h to 36 h.

7. The method for removing trace moisture from carbon dioxide according to claim 1, wherein: In step S1, the specific method of calcination is: continue to increase the temperature at a heating rate of 1°C / min and calcine at 550°C for 6 hours.

8. The method for removing trace moisture from carbon dioxide according to claim 1, characterized in that: In step S2, the concentration of potassium ethoxide in the ethanol solution of potassium ethoxide is 6% to 24%.

9. The method for removing trace moisture from carbon dioxide according to claim 1, characterized in that: In step S3, the carbon dioxide introduced into the adsorption column is carbon dioxide that has been adsorbed by a 5A molecular sieve and has a moisture content of 1 ppm.

10. The method for removing trace moisture in carbon dioxide according to claim 1, characterized in that: In step S3, the carbon dioxide gas is heated to 200 h. -1 The air velocity passes through the adsorption column filled with adsorbent, and the carbon dioxide moisture after passing through the adsorption column is tested.

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