Nitric oxide adsorption purifier

Abstract

The application discloses a nitric oxide adsorption purifier which is installed at a gas outlet of a nitric oxide storage device. The adsorption purifier contains two adsorbents which are respectively used for adsorbing and separating nitrous oxide and laughing gas in nitric oxide gas. The application can separate the laughing gas and the nitrous oxide in the nitric oxide, so that the purity of the nitric oxide is recovered and improved.

Description

Technical Field

[0001] This invention belongs to the field of special gas technology, specifically relating to a nitric oxide adsorption purifier. Background Technology

[0002] Nitric oxide (NO) is widely used in the chemical, electronics, aerospace, metrology, life sciences, and medical fields.

[0003] Nitric oxide readily undergoes a disproportionation reaction under normal temperature and high pressure to produce nitrous oxide (N₂O) and nitrogen dioxide (NO₂), thereby reducing the purity of nitric oxide gas and affecting its application in high-end scenarios such as electronics. When nitric oxide cylinders are stored, the content of nitrous oxide and nitrogen dioxide can reach 200 ppm after 15 days at 3.5 MPa, and after 60 days at 2 MPa, resulting in a decrease in the purity of nitric oxide and an increase in the content of impurities (nitrous oxide and nitrogen dioxide). Even if a significant amount of nitric oxide remains in the cylinder due to prolonged storage, it can still be used, but the high content of impurities (nitrous oxide and nitrogen dioxide) makes it unusable directly. Returning the cylinders to the factory for reprocessing would result in significant waste. Therefore, the purpose of this invention is to restore and improve the purity of nitric oxide in nitric oxide cylinders containing high levels of nitrous oxide and nitrogen dioxide impurities through simple treatment, enabling them to meet usage requirements. Summary of the Invention

[0004] To address the above technical problems, this invention discloses a nitric oxide adsorption purifier, which is installed at the outlet of a nitric oxide storage device to separate nitrous oxide and nitrogen dioxide from nitric oxide, thereby restoring and improving the purity of nitric oxide.

[0005] To achieve the above-mentioned technical objectives, the technical solution of the present invention is a nitric oxide adsorption purifier, which is installed at the outlet of an oxygen monoxide storage device. The adsorption purifier contains two adsorbents, which are used to adsorb and separate nitrogen dioxide and nitrous oxide from oxygen monoxide gas, respectively.

[0006] The preparation method of the adsorbent 1 used for adsorbing and separating nitrogen dioxide is as follows:

[0007] 1.1. Add aluminum sulfate solution dropwise into ammonium bicarbonate solution, stir, and react to produce basic aluminum ammonium carbonate;

[0008] 1.2. After filtration and drying, basic aluminum ammonium carbonate powder is obtained;

[0009] 1.3. After mixing basic aluminum ammonium carbonate powder, grade 1 cellulose, and PEG2000, water is added. After the mixture becomes viscous, it is extruded and molded. The mass ratio of basic aluminum ammonium carbonate powder to grade 1 cellulose and PEG2000 is 100:3:2.

[0010] 1.4. After molding, it is placed in a muffle furnace and heated to dry to obtain alumina;

[0011] 1.5. Immerse alumina in an ethanol solution of ethylenediamine; this treatment can reduce the active sites of alumina and prevent the disproportionation of nitric oxide.

[0012] 1.6. Vacuum treatment of impregnated alumina;

[0013] 1.7. Immerse alumina in a mixed solution of glycine and NaOH;

[0014] 1.8. Remove the impregnated alumina and dry it to obtain adsorbent 1;

[0015] The method for preparing the adsorbent 2 used for adsorbing and separating nitrous oxide is as follows:

[0016] 2.1 Weigh out P123 and dissolve it in HCl solution, stirring until dissolved;

[0017] 2.2 Add alumina powder and tetraethyl orthosilicate to the solution obtained in 2.1; the alumina powder is treated in steps 1.1 to 1.6, excluding step 1.3;

[0018] 2.3 Stirring, add the mixed solution to the hydrothermal reactor for reaction;

[0019] 2.4 After cooling, the solid was obtained by filtration, and then heated and dried to obtain adsorbent 2.

[0020] Preferably, in step 1.1, the aluminum sulfate solution is added dropwise to the 50°C ammonium bicarbonate solution at a rate of 10 ml / min while stirring, and the stirring speed is 100 rpm, until no more precipitate is formed.

[0021] Preferably, the drying in step 1.2 is performed at 70°C for 2 hours.

[0022] Preferably, in step 1.4, the muffle furnace is heated to 500°C at a rate of 1°C / min and maintained for 2 hours.

[0023] Preferably, the pore size of the alumina obtained in step 1.4 is 30-70 nm.

[0024] Preferably, in step 1.5, the alumina is immersed in an ethanol solution of 5% ethylenediamine by volume for 24 hours; in step 1.6, the immersed alumina is vacuum treated at 100°C.

[0025] Preferably, in step 1.7, the alumina is immersed in a 1:1 mixed solution of 0.5 mol / L glycine and 0.5 mol / L NaOH for 24 hours.

[0026] Preferably, in step 2.1, the ratio of P123 to HCl solution is 5g:100ml, and the concentration of HCl solution is 2mol / L; in step 2.2, the weight ratio of added alumina powder, tetraethyl orthosilicate and P123 is 2:2:1.

[0027] Preferably, the stirring in step 2.3 is carried out at 35°C for 8 hours.

[0028] Preferably, in section 2.3, the reaction conditions in the hydrothermal reactor are 100°C for 24 hours.

[0029] Preferably, in step 2.4, the temperature is increased to 500°C at a rate of 5°C / min and maintained for 2 hours.

[0030] Preferably, the two adsorbents in the nitric oxide adsorption purifier are placed in two separate containers.

[0031] In this article, P123 is a triblock copolymer, whose full name is: polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, and its molecular formula is: PEO-PPO-PEO.

[0032] The nitric oxide adsorption purifier of this invention comprises at least two containers, each containing an adsorbent: adsorbent 1 for adsorbing and separating nitrogen dioxide and adsorbent 2 for adsorbing and separating nitrous oxide. In use, the nitric oxide adsorption purifier is installed at the outlet of a nitric oxide storage tank. The valve is opened, connecting the two containers of the adsorption purifier to the storage tank (cylinder). Nitrous oxide and nitrogen dioxide impurities in the nitric oxide gas are then adsorbed and removed by adsorbent 1 and adsorbent 2 in the adsorption purifier, respectively, thereby increasing the purity of the nitric oxide in the storage tank and ensuring that the nitric oxide meets usage requirements.

[0033] The beneficial effects of this invention are as follows: Nitric oxide is extremely unstable; conventional adsorbents and NaOH both lead to the disproportionation reaction of NO. This invention, through a specially formulated adsorbent, solves the problem of increased impurity content and decreased purity of nitric oxide after long-term storage. Even if the content of nitrous oxide and nitrogen dioxide in the storage container (cylinder) exceeds the standard, they can be separated by an adsorption purifier to obtain a high-purity nitric oxide product for application. Furthermore, this invention is simple and convenient, requires minimal equipment investment, and has low cost; nitric oxide cylinders stored for extended periods can be put into use after simple treatment. Detailed Implementation

[0034] The technical solutions of this application will be further described below with reference to specific embodiments, but this application is not limited to these embodiments.

[0035] Example 1:

[0036] A nitric oxide adsorption purifier is provided, wherein the adsorption purifier is installed at the outlet of an oxygen monoxide storage device, and the adsorption purifier comprises two containers and two adsorbents, which are used to adsorb and separate nitrogen dioxide and nitrous oxide from oxygen monoxide gas, respectively.

[0037] The method for preparing the adsorbent 1 used for adsorbing and separating nitrogen dioxide is as follows:

[0038] 1.1. Add aluminum sulfate solution dropwise to ammonium bicarbonate solution at 50℃ at a rate of 10 ml / min, stirring at 100 rpm, to form basic aluminum carbonate ammonium. Continue adding until no more precipitate is formed.

[0039] 1.2. After filtration, dry at 70℃ for 2 hours to obtain basic aluminum ammonium carbonate powder;

[0040] 1.3. Mix 100g of basic aluminum ammonium carbonate powder, 3g of grade 1 cellulose, and 2g of PEG2000, add an appropriate amount of water, and after it becomes viscous, extrude it into strips;

[0041] 1.4. After forming, place it in a muffle furnace and heat it to 500℃ at a rate of 1℃ / min, and hold it for 2 hours to obtain alumina with a main pore size distribution of 30-70nm;

[0042] 1.5. Immerse the alumina in a 5% ethylenediamine ethanol solution for 24 hours;

[0043] 1.6. Vacuum-treated impregnated alumina at 100℃;

[0044] 1.7. Immerse alumina in a 1:1 mixed solution of 0.5 mol / L glycine and 0.5 mol / L NaOH for 24 h;

[0045] 1.8. Remove the impregnated alumina and dry it at 200℃ for 3 hours to obtain adsorbent 1. The preparation method of adsorbent 2 for adsorbing and separating nitrous oxide is as follows:

[0046] 2.1 Weigh 5g of P123 and dissolve it in 100mL of 2mol / L HCl solution, stirring at 35℃ to dissolve;

[0047] 2.2 Add 10g of alumina powder (after steps 1.1 to 1.6, excluding step 1.3) and 10g of tetraethyl orthosilicate to the solution;

[0048] 2.3 Stir at 35℃ for 8 hours; then add the mixed solution to a hydrothermal reactor and incubate at 100℃ for 24 hours;

[0049] 2.4 After cooling, the solid was filtered and heated to 500℃ at a rate of 5℃ / min and held for 2 hours to obtain adsorbent 2.

[0050] The adsorbents 1 and 2 prepared above were respectively placed into containers to form a nitric oxide adsorption purifier. This adsorption purifier was installed at the outlet of a nitric oxide cylinder, and then the contents of nitrogen dioxide and nitrous oxide in the cylinder were tested. Table 1 shows the changes in the contents of nitrogen dioxide and nitrous oxide impurities in NO gas purified by this invention before and after purification.

[0051] Table 1

[0052]

[0053] As shown in Table 1, the content of nitrous oxide and nitrogen dioxide is greatly reduced after adsorption and removal by adsorbent 1 and adsorbent 2, with the removal rate reaching a maximum of 100% and a minimum of 99.26%.

[0054] One application of this invention is the purification of nitric oxide from nitric oxide cylinders that have been stored for a long time. After prolonged storage, nitric oxide undergoes a disproportionation reaction to produce nitrous oxide (N₂O) and nitrogen dioxide (NO₂). However, a significant amount of nitric oxide remains in the cylinder and can still be used. But due to the high content of impurities (nitrous oxide and nitrogen dioxide), it cannot be used directly, and returning the cylinders to the factory for reprocessing would result in considerable waste. Therefore, this invention is used to adsorb and purify nitrous oxide and nitrogen dioxide in the cylinders. As shown in Table 1, the adsorption and purification effect of this invention is excellent; the impurities are almost completely adsorbed, and the purified nitric oxide gas fully meets the needs of production use.

[0055] This invention requires minimal equipment investment and is simple and convenient to implement; it can be completed simply by installing an adsorption purifier containing two adsorbents at the gas cylinder outlet. The nitrogen monoxide gas treated by this invention has increased purity and lower impurity content, meeting the requirements of many industries.

[0056] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of this application, and these all fall within the protection scope of this application.

Claims

1. A nitric oxide adsorption purifier, characterized in that the adsorption purifier is installed at the outlet of a nitric oxide storage device, and the adsorption purifier contains two adsorbents, which are used to adsorb and separate nitrogen dioxide and nitrous oxide from nitric oxide gas, respectively. The method for preparing the adsorbent 1 used for adsorbing and separating nitrogen dioxide is as follows: 1.

1. Add aluminum sulfate solution dropwise into ammonium bicarbonate solution, stir, and react to produce basic aluminum ammonium carbonate; 1.

2. After filtration and drying, basic aluminum ammonium carbonate powder is obtained; 1.

3. After mixing basic aluminum ammonium carbonate powder, grade 1 cellulose, and PEG2000, water is added. After the mixture becomes viscous, it is extruded and molded. The mass ratio of basic aluminum ammonium carbonate powder to grade 1 cellulose and PEG2000 is 100:3:

2. 1.

4. After molding, it is placed in a muffle furnace and heated to dry to obtain alumina; 1.

5. Immerse alumina in an ethanol solution of ethylenediamine; 1.

6. Vacuum treatment of impregnated alumina; 1.

7. Immerse alumina in a mixed solution of glycine and NaOH; 1.

8. Remove the impregnated alumina and dry it to obtain adsorbent 1; The method for preparing the adsorbent 2 used for adsorbing and separating nitrous oxide is as follows: 2.1 Weigh out P123 and dissolve it in HCl solution, stirring until dissolved; 2.2 Add alumina powder and tetraethyl orthosilicate to the solution obtained in 2.1; the alumina powder is treated in steps 1.1 to 1.6, excluding step 1.3; 2.3 Stirring, add the mixed solution to the hydrothermal reactor for reaction; 2.4 After cooling, the solid was obtained by filtration, and then heated and dried to obtain adsorbent 2; The two adsorbents in the nitric oxide adsorption purifier are placed in two separate containers.

2. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In step 1.1, aluminum sulfate solution is added dropwise to ammonium bicarbonate solution at 50°C at a rate of 10 ml / min while stirring. The stirring speed is 100 rpm, and the addition continues until no more precipitate is formed.

3. The nitric oxide adsorption purifier as described in claim 1, characterized in that, The drying in step 1.2 is performed at 70°C for 2 hours.

4. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In step 1.4, the muffle furnace is heated to 500°C at a rate of 1°C / min and maintained for 2 hours.

5. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In step 1.5, the alumina is immersed in an ethanol solution of 5% ethylenediamine by volume for 24 hours; in step 1.6, the alumina after immersion is subjected to vacuum treatment at 100°C.

6. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In step 1.7, alumina is immersed in a 1:1 mixed solution of 0.5 mol / L glycine and 0.5 mol / L NaOH for 24 hours.

7. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In step 2.1, the ratio of P123 to HCl solution is 5g:100ml, and the concentration of HCl solution is 2mol / L; in step 2.2, the weight ratio of added alumina powder, tetraethyl orthosilicate and P123 is 2:2:

1.

8. The nitric oxide adsorption purifier as described in claim 1, characterized in that, In section 2.4, the temperature is increased to 500°C at a rate of 5°C / min and maintained for 2 hours.

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