A device and method for purifying nitric oxide gas

Abstract

The present application relates to a kind of purification method of nitric oxide gas, comprising the following steps: crude nitric oxide gas is imported into extraction column, and the extraction phase obtained after extraction is imported into resolution column for temperature resolution;Nitric oxide gas resolved is imported into ethanol absorption tower after alkali washing tower and condenser;Again imported into the adsorption tower filled with 13X molecular sieve;After adsorption, the gas is collected into product collection bottle, and the purity of more than 99.99% nitric oxide product is obtained.The present application uses ferrous sulfate solution as extractant, extracts refined nitric oxide, realizes the efficient extraction of nitric oxide by the coordination reaction of ferrous ion and nitric oxide in the purification process, then uses ethanol as absorbent, utilizes the significant difference in solubility of nitric oxide and nitrous oxide in ethanol, can selectively absorb the nitrous oxide impurity difficult to remove, finally uses 13X molecular sieve to further remove nitrous oxide, which is beneficial to reduce disproportionation reaction and improve product purity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas purification, in particular to a device and method for purifying nitric oxide gas. BACKGROUND

[0002] Nitric oxide is a permanent gas, colorless, odorless, slightly soluble in water, soluble in ethanol and carbon disulfide and other solvents, its liquid or solid state at low temperature shows blue. Nitric oxide has a wide range of applications in many fields such as fine chemical industry, environmental protection, medical treatment, scientific research and electronics, for example, in the chemical industry to prepare nitric acid, used in nitration process, used as emergency stop agent in polyvinyl chloride industry, used as propellant in space rockets and satellites, etc. In recent years, with the rapid development of the semiconductor industry, the demand for nitric oxide has grown rapidly due to its use in silicon oxide film formation, oxidation and chemical vapor deposition, etc., and the purity requirement is continuously improved, and the demand for high-purity (99.99%) nitric oxide gas is in short supply.

[0003] Patent CN108163823A discloses a method for preparing 4N purity nitric oxide gas, which comprises adding dilute sulfuric acid to sodium nitrite solution to generate crude nitric oxide, and then performing alkali washing, dehydration and primary drying. The gas after primary drying is sequentially subjected to deep drying by modified molecular sieves C2 and C5, and then subjected to adsorption treatment by a deep cold adsorber to collect the product with 4N purity. The modification process of the modified molecular sieves C2 and C5 is as follows: the molecular sieves C2 and C5 are soaked in a 10% nitric acid solution, taken out after 24 hours, and activated and dried at 300°C for 8 hours. Patent CN118651826A discloses a method for refining nitric oxide gas, which comprises adding reaction raw materials, i.e. dilute sulfuric acid and sodium nitrite saturated solution, into a synthesis reactor to generate crude nitric oxide gas. The crude nitric oxide gas is sequentially subjected to alkali washing and condensation dehydration, and finally subjected to three-stage adsorption under deep cooling conditions to obtain nitric oxide gas with purity not less than 99.99%.

[0004] In the above-mentioned patents, during the preparation of nitric oxide, nitric oxide will undergo disproportionation reaction, resulting in a decrease in the yield of nitric oxide. Meanwhile, multi-stage adsorption will also promote the disproportionation reaction of nitric oxide gas, producing nitrogen dioxide and nitrous oxide, which affects the purity and yield of the product.

[0005] Therefore, there is a need to invent a simple, safe and efficient method and device for purifying nitric oxide gas to improve the purity and yield of nitric oxide gas. SUMMARY

[0006] In order to overcome the above-mentioned problems existing in the prior art, the purpose of the present application is to provide a device and method for purifying nitric oxide gas, which can simply, economically and efficiently remove impurities in crude nitric oxide gas, while reducing the loss of nitric oxide gas.

[0007] To achieve the object of the present application, the specific technical solutions provided by the present application are as follows:

[0008] A device for purifying nitric oxide gas comprises an extraction tower, a resolution tower, an alkali washing tower, a condenser, an ethanol absorption tower and an adsorption tower connected in sequence.

[0009] An extraction tower feed port is arranged at the middle position of the extraction tower, and an extraction tower discharge port is arranged at the bottom of the extraction tower.

[0010] A resolution tower feed port is arranged at the middle position of the resolution tower, and a resolution tower discharge port is arranged at the top end position of the resolution tower.

[0011] An alkali washing tower feed port is arranged at the bottom end position of the alkali washing tower, and an alkali washing tower discharge port is arranged at the top end position of the alkali washing tower.

[0012] A condenser feed port is arranged at one end of the condenser, and a condenser discharge port is arranged at the other end of the condenser.

[0013] An ethanol absorption tower feed port is arranged at the bottom end position of the ethanol absorption tower, and an ethanol absorption tower discharge port is arranged at the top end position of the ethanol absorption tower.

[0014] An adsorption tower feed port is arranged at the bottom of the adsorption tower, and an adsorption tower discharge port is arranged at the top of the adsorption tower.

[0015] The extraction tower feed port is in communication with a crude gas source pipeline, the extraction tower discharge port is in communication with the resolution tower feed port pipeline, the resolution tower discharge port is in communication with the alkali washing tower feed port pipeline, the alkali washing tower discharge port is in communication with the condenser feed port pipeline, the condenser discharge port is in communication with the ethanol absorption tower feed port pipeline, the ethanol absorption tower discharge port is in communication with the adsorption tower feed port pipeline, and the adsorption tower discharge port is in communication with a product collection unit pipeline.

[0016] Preferably, the ratio of the diameter and height of the extraction tower is 38:4800, an extractant inlet is further arranged at the top end position of the extraction tower, the extractant inlet is in communication with an extractant tank, and the amount of extractant added is 1 / 4-1 / 3 of the volume of the extraction tower.

[0017] Preferably, the ratio of the diameter and height of the resolution tower is 38:4800, a tower kettle heater is arranged at the bottom of the resolution tower, an extractant outlet is further arranged at the bottom position of the resolution tower, and the extractant outlet of the resolution tower is in communication with an extractant recovery tank.

[0018] Preferably, the ratio of the diameter and height of the alkali washing tower is 1:30, the alkali washing tower is internally filled with sodium hydroxide solution, and the amount of sodium hydroxide solution added is 1 / 3-2 / 3 of the volume of the alkali washing tower.

[0019] Preferably, the condenser is further provided with a refrigerant inlet and a refrigerant outlet, which are communicated with a refrigerant storage tank respectively.

[0020] Preferably, the ethanol absorption tower has a diameter to height ratio of 1:30, and is internally filled with anhydrous ethanol, and the anhydrous ethanol is added in an amount of 1 / 3-2 / 3 of the volume of the ethanol absorption tower; the adsorption tower has a diameter to height ratio of 45:1000, and is internally filled with 13X molecular sieve.

[0021] Preferably, a first valve is arranged on the pipeline connecting the crude product gas source and the extraction tower, a second valve is arranged on the pipeline connecting the extraction tower and the desorption tower, a third valve is arranged on the pipeline connecting the desorption tower and the caustic washing tower, a fourth valve is arranged on the pipeline connecting the caustic washing tower and the condenser, a fifth valve is arranged on the pipeline connecting the condenser and the ethanol absorption tower, a sixth valve is arranged on the pipeline connecting the ethanol absorption tower and the adsorption tower, and a seventh valve is arranged on the pipeline connecting the adsorption tower and the product collecting unit.

[0022] The application further provides a method for purifying nitric oxide gas, which is implemented by the device for purifying nitric oxide gas and comprises the following steps.

[0023] The crude nitric oxide gas is introduced into the extraction tower, and an extractant is fed into the extraction tower from the extractant inlet at the upper end of the extraction tower; after extraction, the obtained extraction phase is introduced into the desorption tower for temperature-rising desorption, and the extractant is recovered from the extractant outlet at the bottom of the desorption tower; the desorbed nitric oxide gas is introduced into the ethanol absorption tower after passing through the caustic washing tower and the condenser; the gas after ethanol absorption in the ethanol absorption tower is introduced into the adsorption tower filled with 13X molecular sieve; the gas after adsorption is collected into a product collecting bottle, and a nitric oxide product with a purity greater than 99.99% is obtained.

[0024] Preferably, the flow rate of the crude nitric oxide gas introduced into the extraction tower is 5-10 L / min, and the extractant in the extraction tower is a ferrous sulfate solution with a concentration of 1-1.3 mol / L.

[0025] Preferably, the temperature of the extraction phase is raised to 100-120 ℃ during desorption in the desorption tower; the caustic washing tower is internally filled with a 5% sodium hydroxide solution; and the refrigerant in the condenser is dichloromethane, and the refrigerant temperature is -30 ℃.

[0026] The device and method for purifying nitric oxide gas have the following beneficial effects:

[0027] 1. This invention uses ferrous sulfate solution as the extractant, achieving efficient extraction of nitric oxide through the coordination reaction between ferrous ions and nitric oxide. This method not only reduces the occurrence of disproportionation reactions but also improves extraction efficiency and reduces the loss of nitric oxide gas, laying a good foundation for subsequent purification steps.

[0028] 2. In the purification process, this invention innovatively uses ethanol as the absorbent. Utilizing the significant difference in solubility between nitric oxide and nitrous oxide in ethanol, this invention can selectively absorb nitrous oxide impurities that are difficult to remove. Furthermore, by using 13X molecular sieves for further deep removal, this invention successfully reduces the nitrous oxide content in the product to extremely low levels, thereby significantly improving the product's purity.

[0029] 3. The purification device of this invention is rationally designed with tight connections between components, reducing the possibility of gas leakage. Simultaneously, by recovering the extractant and utilizing renewable ethanol as the absorbent, this invention reduces production costs and environmental pollution. Furthermore, the dichloromethane refrigerant used in the condenser also has high environmental performance, meeting the green requirements of modern industrial production. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the nitric oxide gas purification device of the present invention;

[0031] The markings in the diagram are as follows: 1. Crude gas source; 2. Extraction tower; 3. Stripping tower; 4. Tower bottom heater; 5. Alkali washing tower; 6. Condenser; 7. Ethanol absorption tower; 8. Adsorption tower; 9. Product collection bottle; 10. Refrigerant storage tank; 11. Extractant recovery tank; 12. Extractant tank. Detailed Implementation

[0032] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0033] Device Examples

[0034] like Figure 1 The diagram shows a schematic of the nitric oxide gas purification device of the present invention. This embodiment provides a device for purifying nitric oxide gas, comprising an extraction tower 2, a stripping tower 3, an alkaline washing tower 5, a condenser 6, an ethanol absorption tower 7, and an adsorption tower 8 connected in sequence. Through the sequentially arranged extraction tower 2, stripping tower 3, alkaline washing tower 5, condenser 6, ethanol absorption tower 7, and adsorption tower 8, this device can achieve highly efficient purification of nitric oxide gas. Each independent processing unit targets specific impurities for removal, thereby ensuring that the final obtained nitric oxide gas has high purity.

[0035] The extraction column 2 is provided with an extraction column feed port at the middle position, an extraction column discharge port at the bottom, and an extractant inlet at the top end position, and the ratio of the diameter to the height of the extraction column 2 is 38:4800; the extractant inlet is connected with an extractant tank 12, the extractant is fed into the extraction column 2 from the extractant tank 12, and the addition amount of the extractant is 1 / 4-1 / 3 of the volume of the extraction column 2; the extraction column feed port is connected with a crude gas source 1 pipeline, and the extraction column discharge port is connected with a desorption column 3. Through the coordination reaction between the extractant and ferrous ions and nitrogen monoxide in the extraction column 2, efficient extraction of nitrogen monoxide is realized, and the occurrence of disproportionation reaction is reduced.

[0036] The desorption column 3 is provided with a desorption column feed port at the middle position and a desorption column discharge port at the top end position, and is provided with a column kettle heater 4 at the bottom and an extractant outlet at the bottom position; the ratio of the diameter to the height of the desorption column 3 is 38:4800; the extraction column discharge port is connected with the desorption column feed port pipeline, the desorption column 3 extractant outlet is connected with an extractant recovery tank 11, and the desorption column discharge port is connected with an alkali washing tower 5. Through the recovery and reuse of the extractant in the desorption column 3, the extraction effect is ensured, and the waste of the extractant is reduced.

[0037] The alkali washing tower 5 is provided with an alkali washing tower feed port at the bottom end position and an alkali washing tower discharge port at the top end position, and the ratio of the diameter to the height of the alkali washing tower 5 is 1:30; the alkali washing tower 5 is filled with a sodium hydroxide solution with a mass concentration of 5%, and the addition amount of the sodium hydroxide solution is 1 / 3-2 / 3 of the volume of the alkali washing tower 5; the alkali washing tower discharge port is connected with a condenser 6. The alkali washing tower 5 is filled with a sodium hydroxide solution with a suitable concentration and volume, which can effectively remove the acidic impurities nitrogen dioxide and carbon dioxide without causing resource waste and environmental problems.

[0038] One end of the condenser 6 is provided with a condenser feed port, and the other end is provided with a condenser discharge port; the alkali washing tower discharge port is connected with the condenser feed port pipeline; the condenser 6 is further provided with a refrigerant inlet and a refrigerant outlet, which are respectively connected with a refrigerant storage tank 10; and the condenser discharge port is connected with an ethanol absorption tower 7. The circulating refrigerant in the condenser 6 can effectively cool the gas to a suitable temperature and remove the moisture.

[0039] The ethanol absorption tower 7 is provided with an ethanol absorption tower feed port at the bottom end position and an ethanol absorption tower discharge port at the top end position; the ratio of the diameter to the height of the ethanol absorption tower 7 is 1:30; the ethanol absorption tower 7 is filled with anhydrous ethanol; the addition amount of the anhydrous ethanol is 1 / 3-2 / 3 of the volume of the ethanol absorption tower 7; the condenser discharge port is connected with the ethanol absorption tower feed port pipeline; and the ethanol absorption tower discharge port is connected with an adsorption tower 8. The anhydrous ethanol filled in the ethanol absorption tower 7 can selectively absorb the nitrous oxide impurities in the gas which are difficult to remove.

[0040] The adsorption tower 8 is provided with an adsorption tower feed port at the bottom and an adsorption tower discharge port at the top, and the ratio of the diameter to the height of the adsorption tower 8 is 45:1000. The adsorption tower 8 is internally filled with 13X molecular sieve. The ethanol absorption tower discharge port is in pipeline communication with the adsorption tower feed port, and the adsorption tower discharge port is in pipeline communication with the product collection bottle 9. The 13X molecular sieve can further deeply remove nitrous oxide and moisture, thereby ensuring that the final obtained nitric oxide gas meets the high-purity requirement.

[0041] The first valve is arranged on the pipeline communication between the crude product gas source 1 and the extraction tower 2. The second valve is arranged on the pipeline communication between the extraction tower 2 and the elution tower 3. The third valve is arranged on the pipeline communication between the elution tower 3 and the alkali washing tower 5. The fourth valve is arranged on the pipeline communication between the alkali washing tower 5 and the condenser 6. The fifth valve is arranged on the pipeline communication between the condenser 6 and the ethanol absorption tower 7. The sixth valve is arranged on the pipeline communication between the ethanol absorption tower 7 and the adsorption tower 8. The seventh valve is arranged on the pipeline communication between the adsorption tower 8 and the product collection bottle 9.

[0042] The implementation principle of the embodiment is that the crude nitric oxide gas is introduced into the extraction tower 2, and an extraction agent is introduced at the same time. The extraction agent is subjected to coordination reaction with the nitric oxide to remove most of the impurities. The extracted phase after extraction is introduced into the elution tower 3, and the nitric oxide gas is eluted again by heating. The eluted gas is introduced into the alkali washing tower 5 to remove the acidic impurities of nitrogen dioxide and carbon dioxide. Then, the gas is introduced into the condenser 6 to remove the moisture. Finally, the gas is introduced into the ethanol absorption tower 7 and the adsorption tower 8. The anhydrous ethanol in the ethanol absorption tower 7 can selectively absorb the nitrous oxide impurities which are difficult to remove in the gas. The 13X molecular sieve in the adsorption tower 8 can further deeply remove the nitrous oxide and moisture, so that the high-purity nitric oxide gas is obtained.

[0043] Method embodiment 1

[0044] The embodiment provides a method for purifying nitric oxide gas, which is implemented by using the device for purifying nitric oxide gas in the device embodiment, and comprises the following steps.

[0045] The crude nitric oxide gas with a purity of 99% is introduced into the extraction tower 2 at a flow rate of 8L / min, and an extraction agent is introduced into the extraction tower 2 from the extraction agent inlet at the upper end of the extraction tower 2. The extraction agent is a 1mol / L ferrous sulfate solution. After the extraction is completed, the extracted phase is introduced into the elution tower 3 for elution by heating. During the elution, the temperature is increased to 110℃. At the same time, the extracted agent eluted from the elution tower 3 is discharged from the extraction agent outlet at the bottom of the elution tower 3, and the extraction agent is recovered.

[0046] The resolved gas is introduced into the caustic washing tower 5, which is filled with a 5% mass concentration sodium hydroxide solution. After the gas is washed to remove nitrogen dioxide and carbon dioxide impurities, it is introduced into the condenser 6 to remove water by condensation. The refrigerant in the condenser 6 is dichloromethane, and the refrigerant temperature is -30°C.

[0047] After the gas passes through the condenser 6, it is introduced into the ethanol absorption tower 7, where the nitrous oxide impurities in the gas are absorbed by anhydrous ethanol. After ethanol absorption, the gas is introduced into the adsorption tower 8 filled with 13X molecular sieve to further remove nitrous oxide and moisture. The gas after adsorption is collected into the product collection bottle 9, and a 99.994% purity nitric oxide product is obtained.

[0048] Method embodiment 2

[0049] The present embodiment provides a method for purifying nitric oxide gas, which utilizes the device for purifying nitric oxide gas in the device embodiment, including the following steps:

[0050] The crude nitric oxide gas with a purity of 99% is introduced into the extraction tower 2 at a flow rate of 8L / min, and an extraction agent is fed from the extraction agent inlet at the upper end of the extraction tower 2. The extraction agent is a 1.2mol / L ferrous sulfate solution. After extraction, the extraction phase is introduced into the resolution tower 3 for temperature resolution. During resolution, the temperature is raised to 120°C, and the resolved extraction agent is discharged from the extraction agent outlet at the bottom of the resolution tower 3 for extraction agent recovery.

[0051] The resolved gas is introduced into the caustic washing tower 5, which is filled with a 5% mass concentration sodium hydroxide solution. After the gas is washed to remove nitrogen dioxide and carbon dioxide impurities, it is introduced into the condenser 6 to remove water by condensation. The refrigerant in the condenser 6 is dichloromethane, and the refrigerant temperature is -30°C.

[0052] After the gas passes through the condenser 6, it is introduced into the ethanol absorption tower 7, where the nitrous oxide impurities in the gas are absorbed by anhydrous ethanol. After ethanol absorption, the gas is introduced into the adsorption tower 8 filled with 13X molecular sieve to further remove nitrous oxide and moisture. The gas after adsorption is collected into the product collection bottle 9, and a 99.994% purity nitric oxide product is obtained.

[0053] Method embodiment 3

[0054] The present embodiment provides a method for purifying nitric oxide gas, which utilizes the device for purifying nitric oxide gas in the device embodiment, including the following steps:

[0055] The crude nitric oxide gas with 99% purity is introduced into the extraction tower 2 at a flow rate of 10 L / min, while the extractant, i.e. the ferrous sulfate solution with a concentration of 1.3 mol / L, is fed from the extractant inlet at the upper end of the extraction tower 2. After the extraction is completed, the obtained extraction phase is introduced into the elution tower 3 for temperature elution. During the elution, the temperature is raised to 100°C, while the eluted extractant is discharged from the extractant outlet at the bottom of the elution tower 3 for extractant recovery.

[0056] The eluted gas is introduced into the caustic washing tower 5, which is filled with the sodium hydroxide solution with a mass concentration of 5% inside. After the removal of the nitrogen dioxide and carbon dioxide impurities through caustic washing, the gas is introduced into the condenser 6 for condensation and water removal. The refrigerant in the condenser 6 is dichloromethane, and the refrigerant temperature is -30°C.

[0057] After the gas passes through the condenser 6, it is introduced into the ethanol absorption tower 7, in which the nitrous oxide impurities in the gas are absorbed by anhydrous ethanol. After the ethanol absorption, the gas is introduced into the adsorption tower 8 filled with 13X molecular sieve, for further deep removal of the nitrous oxide and moisture. After the adsorption, the gas is collected into the product collection bottle 9, and the obtained nitric oxide product has a purity of 99.992%.

[0058] The above description is only the preferred embodiments of the present application, and does not limit the present application in any form. Although the present application has been disclosed as the above preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, are still within the scope of the present application.

Claims

1. An apparatus for purifying nitric oxide gas, characterized by comprising: The device comprises an extraction tower, a resolution tower, an alkali washing tower, a condenser, an ethanol absorption tower and an adsorption tower which are sequentially connected; An extraction tower feed inlet is arranged at the middle position of the extraction tower, and an extraction tower discharge outlet is arranged at the bottom of the extraction tower; A resolution tower feed inlet is arranged at the middle position of the resolution tower, and a resolution tower discharge outlet is arranged at the top end position of the resolution tower; An alkali washing tower feed inlet is arranged at the bottom end position of the alkali washing tower, and an alkali washing tower discharge outlet is arranged at the top end position of the alkali washing tower; A condenser feed inlet is arranged at one end of the condenser, and a condenser discharge outlet is arranged at the other end of the condenser; An ethanol absorption tower feed inlet is arranged at the bottom end position of the ethanol absorption tower, and an ethanol absorption tower discharge outlet is arranged at the top end position of the ethanol absorption tower; An adsorption tower feed inlet is arranged at the bottom of the adsorption tower, and an adsorption tower discharge outlet is arranged at the top of the adsorption tower; The extraction tower feed inlet is in communication with a crude product gas source pipeline, the extraction tower discharge outlet is in communication with the resolution tower feed inlet pipeline, the resolution tower discharge outlet is in communication with the alkali washing tower feed inlet pipeline, the alkali washing tower discharge outlet is in communication with the condenser feed inlet pipeline, the condenser discharge outlet is in communication with the ethanol absorption tower feed inlet pipeline, the ethanol absorption tower discharge outlet is in communication with the adsorption tower feed inlet pipeline, and the adsorption tower discharge outlet is in communication with the product collection unit pipeline; The ratio of the diameter and height of the extraction tower is 38:4800, an extractant inlet is further arranged at the top end position of the extraction tower, the extractant inlet is in communication with an extractant tank, and the amount of the extractant added is 1 / 4-1 / 3 of the volume of the extraction tower; The ratio of the diameter and height of the resolution tower is 38:4800, a tower kettle heater is arranged at the bottom of the resolution tower, an extractant outlet is further arranged at the bottom position of the resolution tower, and the extractant outlet of the resolution tower is in communication with an extractant recovery tank; The ratio of the diameter and height of the alkali washing tower is 1:30, the alkali washing tower is internally filled with sodium hydroxide solution, and the amount of the sodium hydroxide solution added is 1 / 3-2 / 3 of the volume of the alkali washing tower; The condenser is further provided with a refrigerant inlet and a refrigerant outlet, and the refrigerant inlet and the refrigerant outlet are respectively in communication with a refrigerant storage tank; The ratio of the diameter and height of the ethanol absorption tower is 1:30, the ethanol absorption tower is internally filled with anhydrous ethanol, the amount of the anhydrous ethanol added is 1 / 3-2 / 3 of the volume of the ethanol absorption tower, the ratio of the diameter and height of the adsorption tower is 45:1000, and the adsorption tower is internally filled with 13X molecular sieve.

2. The apparatus for purifying nitric oxide gas according to claim 1, wherein A first valve is arranged on the communication pipeline between the crude product gas source and the extraction tower, a second valve is arranged on the communication pipeline between the extraction tower and the resolution tower, a third valve is arranged on the communication pipeline between the resolution tower and the alkali washing tower, a fourth valve is arranged on the communication pipeline between the alkali washing tower and the condenser, a fifth valve is arranged on the communication pipeline between the condenser and the ethanol absorption tower, a sixth valve is arranged on the communication pipeline between the ethanol absorption tower and the adsorption tower, and a seventh valve is arranged on the communication pipeline between the adsorption tower and the product collection unit.

3. A method for purifying nitric oxide gas using the apparatus for purifying nitric oxide gas according to any one of claims 1 to 2, characterized by, The method comprises the following steps: The crude nitric oxide gas is fed into the extraction tower, while the extractant is fed into the extractant inlet at the upper end of the extraction tower. After the extraction is completed, the obtained extraction phase is fed into the desorption tower for temperature desorption, while the extractant is recovered from the extractant outlet at the bottom of the desorption tower. The desorbed nitric oxide gas is fed into the ethanol absorption tower after being washed by the alkali washing tower and the condenser. The gas absorbed by ethanol in the ethanol absorption tower is fed into the adsorption tower filled with 13X molecular sieve. The gas after adsorption is collected into a product collection bottle, and the obtained nitric oxide product has a purity of greater than 99.99%.

4. The method of purifying nitric oxide gas according to claim 3, wherein The flow rate of the crude nitric oxide gas fed into the extraction tower is 5-10 L / min, and the extractant in the extraction tower is a ferrous sulfate solution, and the concentration of the ferrous sulfate solution is 1-1.3 mol / L.

5. The method of purifying nitric oxide gas according to claim 3, wherein When the extraction phase is desorbed in the desorption tower, the temperature is increased to 100-120°C. The alkali washing tower is filled with a sodium hydroxide solution with a mass concentration of 5%. The refrigerant in the condenser is dichloromethane, and the refrigerant temperature is -30°C.

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